An electronic apparatus includes a first apparatus that carries out a plurality of functions, and a second apparatus that is coupled to the first apparatus. The second apparatus comprises a control unit that includes a processing unit for supplying commands to the first apparatus for carrying out the selected one of the plurality of functions: a display driver for displaying on a display a screen utilized to select one of the plurality of functions; and a memory slot operable to receive a memory stick that includes a key file for activating at least one other function. When the key file is uninstalled, the plurality of functions executable by the first apparatus include basic functions, and alternatively when the key file is installed, the plurality of executable functions include both the basic functions and at least one other function upon the processing unit validating authorization data stored on the key file.

1. Field of the Invention
The present invention relates to an electronic apparatus having a plurality of functions in which only a part of functions is generally available, remaining functions being individually made available as optional functions. Also, the present invention relates to a system for managing situations in which optional functions in such electronic apparatus are made available or unavailable.
2. Description of the Related Art
In most of electronic apparatuses, not only some basic functions are available but also optional functions are additionally made available as per user's requests.
In most of electronic apparatuses in which optional functions may be made available additionally, it has been customary that basic functions alone are mounted on the electronic apparatus, other apparatus having optional functions mounted thereon being attached to the electronic apparatus (see Cited Patent Reference 1, for example).
[Cited Patent Reference 1]: Japanese Published Patent Application No. 2002-283651 (paragraphs 0015-0017, FIG. 2)

Electronic apparatus, function selection method of electronic apparatus and management system of electronic apparatus


A polyimide precursor composition includes a polyimide precursor including a condensation polymer of a tetracarboxylic dianhydride composed of a first tetracarboxylic dianhydride having a benzene ring to which two carboxylic anhydride groups are bonded and a second tetracarboxylic dianhydride other than the first tetracarboxylic dianhydride, and a diamine compound; a tertiary amine compound; and a water-soluble solvent containing at least one kind selected from the group consisting of water and aqueous alcohol, wherein the polyimide precursor and the tertiary amine compound are dissolved in the water-soluble solvent.

1. Technical Field
The present invention relates to a polyimide precursor composition, a method for preparing a polyimide precursor, a polyimide molded article, and a method for preparing a polyimide molded article.
2. Related Art
A polyimide resin is a material having characteristics of high durability and excellent heat resistance, and is widely used in electronic material applications.

This patent is subject to a terminal disclaimer.

Polyimide precursor composition, method for preparing polyimide precursor, polyimide molded article, and method for preparing polyimide molded article


A laser printer cartridge comprising including: a housing; a photosensitive drum; a developer cylinder including an inner magnetic member and a coaxial outer sleeve, the internal magnetic member being adjustably mounted on the housing and the outer sleeve being mounted so as to allow rotation about the common axis of the internal magnetic member and the outer sleeve; and means for adjusting the angular position of said internal magnetic member with respect to the housing.

This invention relates to laser printers and more particularly to methods of manufacturing, calibrating, and remanufacturing laser printer cartridges.
The construction and operation of the print engine of a typical laser printer is shown in FIG. 1. Laser printers typically convert a laser signal 10 to a printed image by creating a latent image on a laser-sensitive-photosensitive drum 20 and developing the latent image into a visible image by applying toner powder to the latent image. The toner is transferred from a toner reservoir 30 to photosensitive drum 20 by a developer cylinder 40.
The photosensitive drum 20 is typically an extruded aluminum cylinder. In operation, the surface of the photosensitive drum carries a negative charge. The exterior surface of the photosensitive drum 20 is coated with a layer of an organic-photoconductive material (OPC). The OPC material acts as a photodiode; when exposed to light it becomes electrically conductive in one direction. The photosensitive drum 20 is electrically connected to ground in such a way that charge deposited on exposed portions of the surface of the drum can be conducted from the OPC layer, to the photosensitive drum, and to ground. When a region of the surface of the photosensitive drum 20 is illuminated it becomes conductive and charge is drained from that region (to ground). Areas on the surface of the photosensitive drum 20 which are not illuminated by the laser do not become photoconductive. In typical applications, the charge at a point on the surface which has not been illuminated is -600 V and the charge at a point which has been illuminated is -100 V. The difference in charges over the surface of the drum form a latent image.
The latent image on the surface of the photosensitive drum 20 is developed into a visible image by the application of toner to the laser-exposed regions of the photosensitive drum 20 by the developer cylinder 40. The developer cylinder 40 functions as a valve which regulates the transfer toner from a toner tank or reservoir 30 to the photosensitive drum 20. The developer cylinder 40 generally includes a rotating metallic sleeve 50 with a fixed magnetic member 60 positioned coaxially within the developer cylinder. The developer cylinder is positioned adjacent the photosensitive drum, with its axis parallel to that of the photosensitive drum. A toner cavity or reservoir is positioned adjacent to the developing cylinder 40. The toner generally consists of a fine powder of composite particles. The composite particles include a black plastic resin in which smaller particles of iron are encapsulated. As a point on the surface of the developer cylinder sleeve 50 rotates past the toner supply the magnetic member disposed within the rotating developer cylinder sleeve 50 attracts toner particles onto the surface of the developer cylinder sleeve 50. The depth of the layer of toner on the developer cylinder sleeve 50 is often controlled by a height-control metering blade 70, the gap between the blade and the surface of the developer cylinder controlling the thickness of the toner layer developer sleeve 50.
The developer cylinder 40 is connected to a negative power supply and thus the toner particles on the developing cylinder 40 acquire a negative surface charge. This charge is such that, as the developer cylinder sleeve 50 rotates and brings toner particles into close proximity to the photosensitive drum 20, the particles are attracted to the areas of the photosensitive drum which have been exposed (these areas have a charge of -100 v) and repelled from the areas which have not been exposed (these areas have a charge of -600 v). Transfer of the toner particles is further assisted by applying an AC potential to the developer cylinder 40. The AC potential contributes to overcoming the attraction between the toner particles and the internal magnetic member 60 of the developer cylinder 40 and helps to pull toner on the unexposed areas of the photosensitive drum 20 back to the developer cylinder. A visible image, formed by adherence of toner particles to illuminated areas of the photosensitive drum 20, is thus formed.
The visible image formed on the photosensitive drum 20 is then transferred to paper. Paper, traveling at the same speed at which the surface of the photosensitive drum 20 is rotating, is brought into contact with the photosensitive drum by pickup roller 80 and feed rollers 90. A transfer corona assembly 100, the long axis of which is parallel to the axis of the photosensitive drum 20, is positioned such that the paper passes between the photosensitive drum 20 and the transfer corona assembly 100. (A corona element ionizes the air surrounding it. Ionized air is a conductor of electricity thus the ionized region, or corona, allows a positive charge to migrate to the surface of the paper.) The transfer corona wire 105 produces and deposits a strong positive charge on the back of the paper (the surface not in contact with the pd). This positive charge results in the transfer of the negatively charged toner particles from the photosensitive drum 20 to the paper. As the paper and drum continue to move, the paper peels away from the photosensitive drum 20 and is fed by feeder 110 to a fusing station 120 where the toner is melted and forced into the paper by heat and pressure rollers 125.
After transfer of the image to the paper the rotation of the photosensitive drum 20 carries the region of the surface which has transferred its toner to paper to a cleaning station 130. The cleaning station prepares the surface of the photosensitive drum 20 for a new image. Leftover toner is removed by a urethane cleaning blade 140 which scrapes toner from the photosensitive drum 20 into a waste cavity 150. A sweeper blade 160 in the waste cavity 150 sweeps toner away from the area near the photosensitive drum 20. Erase lamps 170 electrostatically clean the photosensitive drum 20 by illuminating the OPC to neutralize residual charge.
Further rotation of the photosensitive drum 20 brings the cleaned surface to a conditioning station 180. Conditioning consists of the application of a uniform negative charge of -600 V on the surface of the photosensitive drum 20. This charge is deposited on the photosensitive drum 20 by the primary corona assembly 190. The primary corona assembly is positioned with its long axis parallel to the axis of the photosensitive drum 20.
The photosensitive drum 20, developer cylinder 40, toner, toner cavity 30, toner height metering blade 70, cleaner blade 140, waste cavity 150, and primary corona assembly 190 are often contained in a single module referred to as a developer of laser printer cartridge 200. The laser printer cartridge 200 is easily removed and replaced and contains the components most subject to wear or depletion, e.g., the photosensitive drum 20, developer cylinder 40, and toner.

Recycling Technologies International Corporation


A hammer shank and a separate shank butt component for a grand piano hammer assembly with increased rigidity, reduced inertia, and the collateral benefits of increased efficiency of manufacture and maintenance. Hammer shank comprises a long cylindrical member that is connected at one end to a traditional grand piano hammer and at the other end to a novel shank butt. Shank butt comprises: a hammer shank hole, a knuckle slot, a set of two flange attachment holes, and a void area. A traditional grand piano knuckle is attached to the knuckle slot. The shank butt is connected to the repetition flange of the piano. The invention provides the capability for a piano to be played with less touch weight on the keys and therefore provides a more responsive piano keyboard. The invention also allows for full “retrofitability” of hammer assembly into all existing grand piano brands. Embodiments include a composite shank butt that is a molded article and a composite hammer shank that is an extruded or molded article.

This invention relates to key operated percussion devices such as pianos and, more specifically, to the hammer assemblies of such devices. A hammer assembly according to this invention comprises a hammer 40, hammer shank 30, shank butt 20, and knuckle 240.
A piano produces sound as a result of a complicated mechanical chain reaction which starts with the pianist depressing a piano key which in turn actuates a piano action associated with the key which in turn rotates a hammer assembly associated with the piano action which in turn strikes a piano string or strings to make sound.
More specifically, a depressed key 10 gives rise to motion of the damper head assembly (not shown), separating the damper head from the associated set of strings 35, setting the strings ready to accept vibrations. The depressed key 10 also actuates the piano action 15 thereby pushing or "throwing" the associated hammer 40 and hammer shank 30 into the associated set of strings or string 35. The hammer 40 strikes the strings, generating a piano tone. The piano action 15 then receives or "catches" the hammer 40 and hammer shank 30 after it strikes the strings 35 and rebounds back against the action 15. When the pianist releases the depressed key 10, the key 10 returns to the rest position, and permits the damper head assembly to return contact with the vibrating strings 35. The vibrations are absorbed by the damper head assembly, and the piano tone is terminated.
With a grand piano 45, a certain amount of kinetic energy is required when depressing a key 10 in order to move a hammer 40 as imparted by the piano action 15 to the integrated hammer shank (20 and 30). When a key 10 is depressed, the repetition base 70 is pushed upward pivotally about the repetition flange 90. The jack 50 is simultaneously moved upward pivotally about point 100 in the clockwise direction and pivotally about repetition flange 90 in the counterclockwise direction, resulting in a general upward motion. The jack 50 lifts the balancier 60, which also moves upward from double pivot motion, this time about the repetition flange 90 and point 110. The jack 50 raises the knuckle 80 along with the integrated hammer shank (20 and 30) thereby lifting the hammer 40 upwards towards the piano strings 35. The knuckle 80 also slides along the guide surface of the balancier 60. These both cause the hammer 40 to move upward by rotation about point 105 towards the set of horizontally stretched strings or string 35 associated with that key 10. The hammer 40 moves with "free rotation" powered by the knuckle 80 sliding along the balancier 60. The hammer shank 30 is further rotated and disconnects from the balancier 60 in order for the hammer 40 to strike the strings 35.
Likewise, with an upright piano 115, a certain amount of kinetic energy is required when depressing a key 10 in order to move a hammer 40 as imparted by the piano action 15 to the shank butt 20 and hammer shank 30. As the key 10 is depressed, the wippen 120 is pushed up to pivotally move upward, causing the jack 130 to move up together with the wippen 120. The jack 130 is pivotally arranged on the wippen 120. The hammer 40 is then pushed up by the jack 130 through the shank butt 20, and pivotally moves toward a set of vertically stretched strings or string 35. Then, as the jack 130 comes into contact with a regulating button 140, the jack 130 is prevented from moving up and loses contact with the shank butt 20. The hammer 40 and hammer shank 30 continue to move upwards, without contact with the jack 130, and are thus thrown into the string or strings 35 to create piano tone.
At this point, on both grand pianos and upright pianos, conventional wooden hammer shanks 30 bend somewhat before whipping around to strike the strings. This phenomenon can be verified by simple high speed photography of hammer motion resulting from practically every instance of piano playing. The more virtuosic the particular piano piece played, the greater the bending or deflection of the hammer shanks 30. This is because virtuosic piano pieces require greater key depression strength with faster key depression repetitions, which results in more forceful and more frequent hammer assembly rotations. As with all deflection motion, the greater the force applied on the body, the greater the deflection.
Since the energy absorbed by a bending of hammer shank 30 does not directly translate into the production of music, it is wasted energy or energy loss of the system. Thus, more key depression energy is required in order to produce music as a result of the bending of a hammer shank 30. Therefore, the elimination of hammer shank 30 deflection lowers the threshold energy requirement for the creation of sound. Hence the elimination of hammer shank 30 deflection results in a more responsive piano that requires less touch weight on the keys to play the piano.
The grand piano prior art consists of an integral shank butt 20 and hammer shank 30, hereafter known as an "integrated hammer shank", made of wood, typically hornbeam or maple wood. The prior art does not consist of separate shank butt 20 and hammer shank 30 components. Prior art hammer shanks 30 come in one standard diameter or cross sectional area that can be thinned to reduce mass. The reduced mass is particularly required in the treble section because of the need to make the hammer rebound more quickly from the string. Prior art hammer shanks 30 are thinned on an increasing basis gradually as the pitch of the string or strings 35 associated with the particular hammer shank increases. For manufacturing efficiency, this thinning is not continuous but rather is stepped by three separate groups—"thin", "medium", and "thick". "Thick" hammer shanks are not trimmed at all and are used on the bass end of the piano. Hammers 40 are glued onto the hammer shank end of the integrated hammer shank (20 and 30). The integrated hammer shank (20 and 30) is connected to a hammer shank flange 95 by a center pin. The shank flange 95 is attached to the shank rail on the piano. The deflection referenced above occurs in the integrated hammer shank (20 and 30).
The applicants have conducted experimental analysis on grand piano integrated hammer shanks (20 and 30) made of hornbeam wood in order to determine their average rigidity. An integrated hammer shank (20 and 30) was clamped tight and secure on the shank butt end while weight was applied at 4.00″ from the clamping point. A 4″ effective length was used as this length is typical for grand piano integrated hammer shanks (20 and 30). Deflection 250 was measured at 3.79″ from the clamping point. Deflection 250 from various weights was recorded. See FIG. 3 for a depiction of the setup used to quantify the rigidity of the prior art integrated hammer shanks (20 and 30). The results of the deflection experiment are summarized in the table below.
Prior Art Integrated Hammer Shank Rigidity Test
"Thick" HB"Medium" HB"Thin" HBAverageAverageAverageWeight AppliedDeflectionDeflectionDeflection(lbs)(inches)(inches)(inches)00001.00.0660.0600.0752.00.1320.1190.1513.00.1960.1770.2304.00.2630.2400.3115.00.3330.3070.3916.00.4120.3470.473
The relationship is linear, i.e. deflection 250 varies linearly in relation to the change in weight applied. Thus, the degree of deflection, which is inversely proportional to rigidity, of the integrated hammer shank (20 and 30) may be represented by a constant. In this case, the constant is given in the units of inches of deflection 250 per pound of weight applied and is determined by dividing the deflection number by the weight number listed above. The degree of deflection 250, defined as "deflectability", of the hornbeam integrated hammer shank (20 and 30) going form thick, medium, to thin is 0.066 in/lbs, 0.060 in/lbs, and 0.077 in/lbs respectively. The standard deviation of these measurements is less than 0.0015 in/lbs in all cases. Note the smaller the deflectability measurement, the greater the rigidity of the integrated hammer shank (20 and 30). Also note that hornbeam wood has greater specific gravity than that of maple wood and is, thus, more rigid than maple wood. Therefore, hornbeam integrated hammer shanks (20 and 30) are more rigid than their maple counterparts.
The complicated mechanical chain reaction required to strike piano strings deeply affects the music generated by the piano. With most string instruments, the musician touches the strings directly with his hand or directly through a non-dynamic instrument such as a pick or a bow. Conversely, the pianist must depend on a series of mechanical actions, assembled from many small parts, to strike the strings. A pianist varies the speed, force, repetition, acceleration, timing, and other characteristics in near endless combinations when depressing and releasing keys in order to produce various piano tones to yield artistic piano music.
The preferred "feel" of a piano action has come into acceptance more from tradition rather than from methods associated with modern engineering and material science. In the early 1900's, manufacturers used the best available materials at the time, to practically produce high quality piano actions. Hardwood and felt were the primary materials used to produce piano actions at that time. For better or for worse, pianists, to this day, strongly prefer wood/felt actions simply because they deliver the feel consistent with what they grew up with, leading to the propagation of more wood/felt actions, leading to newer generations of pianists learning to play on wood/felt actions, leading to the same preference with new generations, and so on.
Relative to more modern materials, such as composites or plastics, wood is an inefficient raw material from which to manufacture piano action components. Wooden action pieces must be drilled to produce the holes required for pivotal connections and assembly with other action components. The hole-drilling process is a laborious and costly process as compared to the production of molded piano action pieces with holes accurately formed therein during the initial molding process. Also, the production of any finished wooden piece necessarily involves relatively large quantities of wasted material in the form of saw dust, which is inefficient and wasteful.
Wood is hydroscopic, i.e. wood swells or shrinks as its moisture content changes in response to the environmental. This can cause binding in the action. Additionally, after repeated occurrences, this causes compression of the wood leading to failure of the piano action component. For instance, wooden flanges often crack due to expansion from a rise in moisture content, as the screw crushes the wood in the flange where it is fastened to the rail.
Moreover, wood has different strengths in different directions, complicating manufacturing processes, also resulting in reduced manufacturing efficiencies. Additionally, wood has inferior rigidity and strength as compared to modern composites and plastics. In particular, rigidity and strength is of the utmost importance to the hammer assembly portion of the complicated mechanical chain reaction of a piano.
Finally, the lifespan of wooden piano action components is limited as compared to that of other materials such as composites or plastics because wood eventually crumbles into dust after a certain amount of environmental cycles. On the other hand, composite piano action components would have several times the life span of that of their wood counterparts and thus result in more efficient manufacture and maintenance of a piano.


The machine for producing coffee beverages comprises a device to contain coffee powder and another device to supply a fluid to produce the coffee beverage, both devices being reciprocally mobile so that when connected together they form a coffee powder infusion chamber. The container device connected to the machine is removable. The machine comprises an interception tap for water or liquid in the form of a hollow body having at, least a first and second communicating space with the exterior and equipped with a piston connected in sliding mode to the internal part, forming together with said body at least four chambers inside which steam or liquid can be passed alternatively. The fluid supply device is connected to the boiler so that it is heated by the heat dispersed from the boiler.

Traditional machines comprise a device to hold the ground coffee and the water united in a single unit that also forms the ground coffee infusion chamber; moreover, the machines also include a dosing device for the ground coffee, a moving action mechanism, a boiler, etc.
In the known machines, the container-supply device is removable, for example, for cleaning or maintenance purposes. In fact the container-supply device is the part that is most often soiled because it is always in contact with the ground coffee and because the infusion operation occurs inside this device.
However, washing of this device is extremely difficult, and in certain cases, can also damage the machine. In fact, it is very complicated to obtain access to the internal parts of the container-supply device, and this hinders correct and complete cleaning, especially of the filter.
Moreover, since the container-supply device includes parts that move relative to one another, it is possible that the lubricant is removed, or that certain components are removed or displaced from their correct position during washing operations. The consequences are easy to imagine, both in terms of possible machine damage and in terms of unsatisfactory coffee quality.
A further problem with traditional machines concerns the fact that the machine will produce good quality coffee only when the intervals between one coffee production operation and the next are very short. In the machines for the production of a coffee (in particular domestic versions) that are used with average frequency, the time lapse between the preparation of one cup of coffee and the next is generally too long to guarantee that the internal machine parts, and in particular the water pipes, are still hot. Therefore the quality of the coffee produced by the machine is limited.


A connecting structure of a printed circuit board of a liquid crystal display (LCD) module includes a double side printed circuit board and a single side printed circuit board. With the design of the double side printed circuit board having a solder element with two solder surfaces with a plurality of plated through holes (PTHs), and the design of the opening neighboring the solder element, the conducting surface of the single side printed circuit board may easily accord with the structural requirements to select the corresponding solder surface for performing welding.

1. Field of Invention
The present invention relates to a connecting structure of a printed circuit board. More particularly, the present invention relates to a connecting structure of a flexible printed circuit board of a liquid crystal display (LCD) module.
2. Related Art
Recently, because the objectives of the electronic products are light, thin, short and small, many electronic devices develop according to the objectives, and the using of the flexible printed circuit board totally accord with the requirement of the modern technology. In addition, due to the unique flexibility of the flexible printed circuit board, the three-dimensional stereo wiring may be easily accomplished together with the spatial configuration, such that the flexible printed circuit board is widely used, particularly, it is usually applied in the LCD module, so as to serve as the bridge electrically connecting different circuit elements.
Referring to FIG. 1, it is a schematic view of the connecting structure of the flexible printed circuit board of the conventional LCD module. As shown in FIG. 1, the LCD module 10 mainly includes a LCD panel 16, a backlight module 17, a first flexible printed circuit board 13, a second flexible printed circuit board 14 and a mainboard printed circuit board 18.
The LCD panel 16 is connected to the mainboard printed circuit board 18 through the first flexible printed circuit board 13, so as to achieve the signal transmission. The backlight module 17 uses the second flexible printed circuit board 14 as the carrier of the circuit. Usually, the second flexible printed circuit board 14 is connected to the first flexible printed circuit board 13 by welding, and the first flexible printed circuit board 13 is connected to the mainboard printed circuit board 18.
A solder surface 131 is formed on the first flexible printed circuit board 13. The second flexible printed circuit board 14 has an extending portion 15, and a conducting surface 12 is formed on the extending portion 15. Through the welding of the conducting surface 12 and the solder surface 131, the effect of the electrical connection between the LCD panel 16 and backlight module 17 is achieved.
Usually, the first flexible printed circuit board 13 is a double side printed circuit board structure, and its connecting position with the second flexible printed circuit board 14 is at a solder surface 131 on one side of the first flexible printed circuit board 13. The second flexible printed circuit board 14 mainly adopts the double side printed circuit board structure, both of the two sides have a conducting surface 12, and the two conducting surfaces 12 may be welded with the solder surface 131.
As shown in FIGS. 2A and 2B, a sectional view and a top view of the conventional connecting structure of the first flexible printed circuit board of the double side printed circuit board structure and the second flexible printed circuit board of the double side printed circuit board structure are shown. A plurality of first pads 21 and a plurality of second pads 22 are respectively disposed on the solder surface 131 and the conducting surface 12, wherein the area of the first pad 21 may be larger than, equal to or less than the area of the second pad 22. In the figures disclosed by this embodiment, the area of the first pad 21 is larger than the area of the second pad 22. During the welding operation, according to the structural requirements, the second pad 22 on any conducting surface 12 is selected to correspond to the first pad 21 on the solder surface 131 to get into contact with each other. Because the area of the first pad 21 is larger than the area of the second pad 22, the first pad 21 still leaves a protruding portion 21a after contacting, the solder 23 may be welded with the non-contacted second pad 22 through the protruding portion 21a. Moreover, a part of the solder located on the first pad 21 spills to the second pad 22 on the other side through the plated through holes (PTHs) formed on the second pad 22.
Although the above bonding structure is convenient for the bonding process, the second flexible printed circuit board of the double side printed circuit board structure is expensive, and the production cost is increased correspondingly.
Therefore, in order to save the material cost, the conventional method changes to adopt the second flexible printed circuit board of the single side printed circuit board structure, according to different connecting manners, the connecting structures usually have the following two configurations.
As shown in FIGS. 3A and 3B, a sectional view and a top view of the conventional first connecting structure of the first flexible printed circuit board of the double side printed circuit board structure and the second flexible printed circuit board of the single side printed circuit board structure are shown. The second pads 22 disposed on the second flexible printed circuit board and the first pads 21 disposed on the first flexible printed circuit board are not directly contacted, that is, the second pads 22 and the first pads 21 are disposed on the same side of the flexible printed circuit board. During the welding operation, the solder 23 is used to connect the protruding portion 21a of the first pad 21 and the second pad 22. However, whether the strength of the welding structure is appropriate becomes a hidden trouble of the product yield. Usually, in order to make the welding structure have the substantive bonding strength, it is necessary to provide enough amount of solder, thus the tin bead is usually too big, causing the problems on the product assembling or the appearance dimension. On the contrary, if the amount of the solder is not enough, the bonding section is too small, it is impossible to provide enough bonding strength, and the tin crack is easily generated because of the external force, thus resulting in the poor electrical connecting.
As shown in FIGS. 4A and 4B, a sectional view and a top view of the second conventional connecting structure of the first flexible printed circuit board of the double side printed circuit board structure and the second flexible printed circuit board of the single side printed circuit board structure are shown. Different from the connecting method shown in FIGS. 3A and 3B, the second pad 22 and the first pad 21 are bonded by contacting directly. In order to make the solder 23 sandwiched between the solder surface 131 and the conducting surface 12 achieve the melting state, it is necessary to increase the welding temperature and to prolong the welding time. However, the heat energy must be transmitted though the protective layer of the flexible printed circuit board, usually the circuit board is burnt and becomes black. Because the solder 23 is located between the two pads, during the welding process, it is not easy to observe the melting condition of the solder 23, so usually the false bonding occurs, resulting in the poor electrical connecting, and thereby influencing the product yield.

Connecting structure of printed circuit board of liquid crystal display module


Flame-retarding additives that may also have insulating properties are disclosed that include at least one carbonate salt, and at least one additional salt, active ingredient or combination thereof. In addition, methods of forming flame-retarding additives are disclosed that include providing at least one carbonate salt, providing at least one additional salt, active ingredient or combination thereof; and combining the at least one carbonate salt along with the at least one additional salt, active ingredient or combination thereof to form the flame-retarding additive. Flame-retarding additives disclosed may also comprise at least one filler material, including sand or white sand. These additives may also be included in paints and a number of processed building materials.

Many of the conventional building materials, including wood, wood composites, siding, glass, roofing, paint, insulation, flooring, foam insulation and related materials can be either flammable or present hazardous risks when in contact with extreme heat and/or fire. In addition, many of these materials are not designed to provide the high degree of insulative properties that are now in demand among consumers, as energy prices increase and temperatures fluctuate. For example, building materials used in most structures such as dwellings, commercial facilities and storage facilities include fabrication components such as wood, wood products, plastics, other synthetic materials and socalled composite materials. In addition, many of these man-made materials such as plastics, synthetics and composite materials utilize binder materials which are highly volatile when heated and which are highly flammable and, in some instances, actually explosive in character.
As a result of the pervasive and continuing use of flammable or combustible materials in construction, consumers have recognized and imperative need for protective materials which attempt to either render such materials to be flame or fire resistant or to provide a substantial improvement in heat insulation and resistive character. In addition, in high-fire risk areas and warmer climates, improved building materials that can not only resist attack by fire, but also insulate the enclosed spaces would be welcome.
U.S. Pat. No. 4,095,985 issued to Brown discloses thermal barrier compositions in which a composition is particularly adapted for coating structural surfaces to provide them with a thermal carrier to protect them from the detrimental effects of fire comprises an aqueous mixture of (a) lithium mica, (b) wollastonite, (c) aluminum trihydrate, (d) nepheline syenite, and (e) soda bicarbonate. The composition may be diluted with water to facilitate application. The composition may also contain raw vermiculite, sodium aluminum sulfate, borax, calcium sulfate, sodium silicate and other additives to improve the fireproofing, insulation and/or structural strength properties of the material.
U.S. Pat. No. 5,112,533 issued to Pope et al. discloses fire suppression compositions, which are produced by reaction of lignosulfonates with carbonate of soda to produce low-cost chemical reagents useful for fighting fires in progress or for treating flammable materials to render them non-flammable. Methods for producing the fire retardant compositions in liquid, foam or adhesive form are also disclosed.
U.S. Pat. No. 4,168,175 issued to Shutt discloses fire retardant compositions, which are generally non-caking compositions of intimately intermixed ammonium phosphate, e.g. mono and/or diammonium phosphate; sodium tetraborate containing molecularly bound water, e.g. the decahydrate, borax; and fractured finely ground solid powder particles of soda-containing silicate glass which have a high and irregular surface area and an active dry moisture absorbent surface condition for maintaining the particles of ammonium phosphate and sodium tetraborate in moisture protected disposition and for inhibiting the tendency of such particles to adhere to one another.
U.S. Pat. No. 4,515,633 issued to Cruz. Jr discloses polymeric materials combined with modified hydrated magnesium aluminosilicates, where the aluminosilicates are treated with aqueous acidic solutions and subjected to controlled agitation to convert highly porous concertina-shaped granular hydrated magnesium aluminosilicates into groups of electrolyte insensitive platelets. Water slurries of the groups of platelets when dried to form coherent, continuous sheets which when mechanically disintegrated may be reslurried in water. The modified heat exfoliated magnesium aluminosilicates are adapted for use in fire retardant, loose fill cellulose insulation, paper and pulp products, synthetic polymeric materials, coatings such as fire retardant acoustic coatings, dog foods, defoliants and the like.
U.S. Pat. No. 4,218,502 issued to Graham et al. discloses fire retardant products, such as asphalt roofing material, made fire-retardant by inclusion of a layer of intumescable hydrate soluble silicate particles. Preferred soluble silicate particles carry a protective moisture-resistant coating which increases the life of the roofing material, and also makes possible convenient manufacture of the particles. The protective coating includes a metal cation capable of reacting with the silicate ion of the core particle to form a reaction product that is less soluble than the core particle. The reaction is believed to seal any openings in the protective coating, thereby lengthening the effective life of the coating. Besides utility in roofing materials, the coated particles are useful as fire-retardant additives in many other products, including polymeric articles, sheet materials, coating compositions, etc,
U.S. Pat. No. 5,480,587 issued to Musselman et al. discloses materials that may be used as fire retardant additives that includes a discussion of a method of modifying an inorganic material which evolves gases and/or vapors at a temperature which is detrimental to the processing the temperature of polymer or paper systems, so that the modified material can be used as a fire retardant additive with that polymer or paper system. The method comprises the steps of: (1) providing a first material; (2) treating the first material to remove the portion which involves gas which is detrimental to the processing of the polymer or paper system; and (3) combining a second material with the first material to create a modified material which does not evolve gas at a temperature which is detrimental to the processing of the paper or polymer system.
U.S. Pat. Nos. 5,695,691 and 5,948,323 issued to McLaughlin et al. discloses flame retardants and smoke suppressing compounds, along with the methods of manufacturing them, which includes compounds that provide flame retardancy and/or smoke suppressant properties to fibers, textiles, polymeric articles, paper, paint, coating and insulation. More particularly, these compounds include colloidal-sized particles of hydrated salts, organic phosphates, metal borates, polyamides, solid halogenated flame retardants with a melting point greater than 250° C., molybdenum compounds, metallocenes, antimony compounds, zinc compounds, bismuth compounds and other solid chemicals which act as flame retardants or smoke suppressants.
Although there appear to be about as many patents and patent applications related to fire retardant compositions and additives as there are chemicals in the Merck Index, one thing is clear when reviewing the conventional art related to fire retardants and insulation materials—there is no one additive that is a) simple to manufacture, b) simple in its list of components, c) easily incorporatable into and onto a number of building materials, and d) able to function as both a fire retardant and insulator. Surprisingly, an additive has been discovered and produced that meets all of these goals and desirable attributes. This additive will be disclosed herein.

Fire-resistant and insulating additives for building materials, their methods of production and uses thereof


According to the prior art, through-holes in components are often introduced after the production (casting) of the component. This entails additional outlay in terms of time and equipment. The time required can be considerably shortened if a casting mold is designed in such a way that the through-hole is at least in part formed by corresponding projections being formed on the inner wall and/or the outer wall of the casting mold.

Components which are designed as hollow bodies with complex geometries and complex through-holes in the region of an outer wall of the component can be produced in various ways.
Many components, in particular metallic components made from alloys, are produced by casting processes, for example by the investment casting process. In this process, in a first step a casting mold which at least in part represents the negative of the component to be produced is produced from a wax model of the component by the wax model being encased in ceramic.
Through-holes in the walls of hollow components, such as for example film-cooling holes in turbine components, are usually introduced at a later stage by means of a laser and its laser beams, as shown by U.S. Pat. No. 6,329,015 B1. The laser beam guidance is very complex. This entails remachining of the casting or of the directionally solidified component. Consequently, processes for producing a casting with holes which are introduced at a later stage, in particular through-holes, are therefore time-consuming.


Forming a semiconductor device in an NVM region and in a logic region using a semiconductor substrate includes forming a dielectric layer and forming a first gate material layer over the dielectric layer. In the logic region, a high-k dielectric and a barrier layer are formed. A second gate material layer is formed over the barrier and the first material layer. Patterning results in gate-region fill material over the NVM region and a logic stack comprising a portion of the second gate material layer and a portion of the barrier layer in the logic region. An opening in the gate-region fill material leaves a select gate formed from a portion of the gate-region fill material adjacent to the opening. A control gate is formed in the opening over a charge storage layer. The portion of the second gate material layer is replaced with a metallic logic gate.

1. Field
This disclosure relates generally to semiconductor processing, and more specifically, to a method for forming a split-gate device.
2. Related Art
Many semiconductor devices include, or embed, non-volatile memory (NVM) transistors with other transistor types on the same integrated circuit (IC). The manufacturing processes for the different transistor types may not be the same, requiring that the processes be integrated. For example, to integrate NVM with, for example, CMOS (complementary metal oxide semiconductor), the CMOS process may be modified to include the process steps necessary to fabricate the NVM cell and the supporting devices.
Flash NVM is commonly embedded in, for example, system-on-a-chip (SoC) integrated circuits having CMOS logic circuitry. The flash NVM may include a charge storage layer comprising nanocrystals or an ONO (oxide-nitride-oxide) layer. The memory cell may also include a control gate comprising polysilicon, a metal, or both. In addition, it may be desirable to use a high-k (where k refers to the dielectric constant of the material) gate dielectric in the logic transistor. Integrating the non-volatile memory cell with the logic transistor having the metal gate and the high-k gate dielectric on the same integrated circuit may require many additional process steps.
What is needed is a process integration methodology to efficiently embed an NVM cell array with metal gate/high-k dielectric logic transistors.


The present invention provides a laminated glass for vehicles exerting the functions that are difficult to be made compatible in combinations such as (1) a shade band in an interlayer and an optical device such as a CCD camera, (2) a heat shielding interlayer and an optical device, and (3) a heat shielding interlayer and a combiner. In this laminated glass for vehicles, the interlayer includes a first region and a second region that is either enclosed by the first region or formed by partially recessing an edge portion of the first region. The first region is provided with a light reducing function that imparts a light transmittance loss at least of visible light, and in the second region, the interlayer has a light transmittance loss of visible light that is smaller than that in the first region.

To improve a glare reducing property and a heat shielding property, a laminated glass for vehicles such as a windshield sometimes has a band-shaped shade region (a shade band) that is colored green, blue or the like. Although a shade-band may be provided on a surface of a glass sheet, it generally is formed by partially coloring an interlayer for joining glass sheets along a strip. There is a region in windshields where by law a visible light transmittance should be a predetermined value (e.g. 70%) or more. In this description, this field hereinafter is often referred to as "a visual field region". Thus, a shade-band should be formed out of the visual field region, and generally is arranged in an upper area of the windshield.
To absorb heat radiation and ultraviolet rays, colored glass sheets frequently are used for a laminated glass for vehicles, especially for automobiles. Typical colored glass sheets include a green glass sheet that contains more iron-based ingredients than usual. Nowadays, it is proposed that an interlayer also has an infrared ray absorbing function. For example, this function can be added to the interlayer by dispersing electrically conductive minute particles of ITO (indium tin oxide) or the like into the film made of a thermoplastic resin such as polyvinylbutyral (PVB), as disclosed in JP8-259279A. This infrared ray absorbing function derived from an interlayer mostly is imparted to the whole area of the windshield that includes the visual field region.
In recent years, the need for installing various devices in vehicles has arisen so as to achieve an ITS (intelligent transport system) communication or the like. Examples of the devices include a photoreceiver such as a CCD (charge coupled device) camera or a rain sensor for detecting the light that has a wavelength in a visible and infrared range and that passes through a window glass, especially a windshield. When the photoreceiver is installed on the interior surface of a windshield, it is desirable that the photoreceiver is arranged in an upper region of the windshield so as to secure safety and exert the function of the photoreceiver sufficiently.
However, as explained above, a shade-band frequently is formed in the upper region. The shade band considerably lowers the light transmittance of the windshield in a visible and infrared range, and thus deteriorates the sensitivity of the photoreceiver that receives the light through the windshield. Therefore, conventionally, the position of the photoreceiver is forced to change or the use of the photoreceiver with the shade band should be abandoned. Similarly, when the windshield includes an interlayer that has a heat shielding property, the sensitivity of the photoreceiver cannot help decreasing, especially when the photoreceiver detects infrared rays.
Some vehicles have a HUD (head-up display) for displaying information that is necessary for driving such as a vehicle speed on a windshield. A HUD requires a light source installed inside the vehicle and a reflectance increasing film (combiner) for reflecting the light from the source toward the eyes of the operator. In general, the combiner is formed on an inside surface of the windshield within its visual field region.
However, in the windshield that includes a heat-shielding interlayer, the film as well as a combiner lowers the visible light transmittance of the windshield. Thus, the transmittance in the region where the combiner is formed is sometimes below the legal limit. When the windshield includes a colored glass sheet that is excellent in a heat shielding property, the replacement of the colored glass sheet by a normal clear glass sheet increases the visible light transmittance of the windshield. However, this replacement for increasing the visible light transmittance in a partial region decreases the heat shielding property over the whole region.
As explained above, (1) a shade band and a photoreceiver, (2) a heat shielding interlayer and a photoreceiver, and (3) a heat shielding interlayer and a combiner are difficult to be made compatible with each other in a practical use since the shade band and the heat shielding film decrease the light transmittance.
Conventionally, when the need for partially changing the optical property of the windshield arises, a thin film is partially formed on the glass sheet. This is convenient to specify the region where the property should be changed for a HUD combiner or the like since the glass sheet is cut into a predetermined shape prior to a lamination step. A ceramic print that should be formed in a frame shape in a windshield is printed on the surface of the glass sheet.
On the other hand, when the need for imparting some function to a relatively wide region or the whole region of a windshield arises, the function is frequently added into an interlayer of the windshield. This is because the addition of functional materials into an interlayer that is made of organic materials is often advantageous in reducing a manufacturing cost, and an interlayer is used for forming a shade band or adding electrically conductive minute particles, for example. In most cases, interlayers are supplied to a lamination step in a rolled-up state, and thus it is considered inappropriate to treat them partially in regions that correspond with predetermined regions of windshields.
Thus, under these circumstances, to achieve the combinations of (1) to (3), an anti-reflecting film should be formed on a predetermined region of a windshield where a photoreceiver should be arranged so as to increase the light transmittance of the region. However, when relying on such a conventional approach, the sensitivity of the photoreceiver cannot be restored sufficiently or the reflectance of the combiner needs to be lowered for the legal limitation on the visible light transmittance.

Laminated glass for vehicles and method for manufacturing the same


The present invention is based on the discovery that parenteral nutrition (PN) induced liver disease, e.g. fatty liver disease, can be prevented and even reversed by administration of primarily omega-3-fatty acid with PN rather than the administration of the standard intravenous lipid emulsions that contain primarily plant derived omega-6 fatty acid. Thus, the present invention provides a method for treating or preventing liver disease in a human patient obtaining nutritional support through PN. The method comprises intravenous administration of an effective amount of an omega-3-fatty acid emulsion to the patient, wherein the patient is not administered phytosterols or plant derived fatty acids, e.g. omega-6 fatty acids derived from a plant source, and wherein the administration of the omega-3-fatty acid emulsion to the patient is for a period greater than three weeks. Preferably, the administration is for a period of greater than six weeks. More preferably, the administration is for a period greater than three months.

Nutrition support through Parenteral Nutrition (PN) is necessary when patients can not be fed orally, for example when a patient has an impaired GI tract and is unable to tolerate enteral feedings.
PN is a solution that contains fluids, carbohydrates, electrolytes, proteins, amino acids, vitamins; and trace minerals. PN is administered concurrently with an intravenous lipid emulsion that provides essential fatty acids. Commercially available lipid emulsions that are currently used for parenteral use include Intralipid® (Clintec), Liposyn® and Liposyn II® (Abbott Laboratories), Travemusion® (Baxter Healthcare), and Soyacal® (Alpha Therapeutics). These lipid emulsions are composed of a vegetable oil, such as soybean oil or safflower oil, an emulsifying agent such as egg phospholipids, glycerol, and water. Thus, the fatty acid content consists of primarily of the essential omega-6 fatty acids.
The use of PN in patients of all ages has been associated with liver disease, ranging from hepatic steatosis to cirrhosis and ultimately liver failure (1-4, 13-17). Investigators have proposed that it is deficiencies or toxicities of the PN solution that lead to hepatic injury (22-24) and relatively little attention has been given to idea that the lipids delivered with PN pose the problem. In fact, a leading pediatrics textbook, Principles and Practice of Pediatrics, indicates that there is little evidence to suggest that intravenous fat or glucose are associated with the liver disease hepatic cholestasis (Frank A Oski, Deangelis, C D, Feigin R D, McMillan J A, Warshaw, J B, J B lippincott Company 3rd edition: page 1914 (Philadelphia)).
A fish oil based lipid emulsion Omegaven® (Fresenius Kabi), has been developed and used in the European market. Omegaven® is a 10% fish oil emulsion with a high percentage of omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosapentaenoic acid (DHA). Simultaneous intravenous administration of Omegaven with a basic lipid emulsion such as Intralipid® provides what is believed to be an optimal ratio of omega-3 to omega-6 fatty acids. The combination of an omega-6 fatty acid lipid emulsion and a seal oil based emulsion, which is rich in omega-3 fatty acids, has also been proposed for use in PN (PCT WO 03/055323).
A study in a newborn pig model showed that intravenous administration of fish oil, which consists of primarily omega-3 fatty acids, reduced parenteral nutrition-induced cholestasis (39). However, the study was only 3 weeks in duration and long-term effects from administration of omega-3 fatty acids alone were not evaluated. In fact, the idea that one could remove an essential fatty acid from the standard regime of nutritional support by PN has not been accepted by those skilled in the art. It is believed that reduction of an essential fatty acid, such as omega-6, during a long-term therapy would clearly result in fatty acid deficiency and deterioration of the health of the patient.
PN associated liver disease is a significant drawback of parenteral nutrition. It presents a severe problem in newborns and infants who are a significant risk of developing chronic liver disease (18, 19). In addition, the prolonged use of PN in children and adults ultimately leads to non-alcoholic fatty liver disease (NAFLD). Thus, there is a need in the art to identify a means for nutritional support that does not lead to such devastating disease.

Treatment and prevention of liver disease associated with parenteral nutrition (PN)


A packaged semiconductor device having an integrated circuit (IC) die, a flexible tube, and a metal slug. During assembly, a first end of the tube is mounted on a surface of the IC die and a second end of the tube extends away from the die surface. The exposed portions of the surface of the IC die are encased in a molding compound, which also encases the perimeter of the tube. After molding, the tube may be filled with metal to improve conduction of heat away from the die top. If the tube is formed of a soft material like rubber then the tube will not damage the die top during attachment thereto.

The present invention relates generally to semiconductor packaging, and more particularly, to a semiconductor package with a tube-based heat spreader.
With the miniaturization of integrated circuits, heat removal has become more important. If heat is not adequately dissipated from an integrated circuit die, then the integrated circuit could overheat, resulting in decreased performance and possibly even failure. To help dissipate heat, some conventional packaged semiconductor devices are configured with heat spreaders. In general, a heat spreader disperses heat emitted from an integrated circuit to an area of the package that is away from the integrated circuit.
Heat spreaders are usually made of metal such as copper because of its good thermal characteristics. Typically one end or side of the heat spreader is attached to a surface of the die and the other end or side of the heat spreader is exposed. However, since the heat spreader comprises metal, when it is attached to the die top, it can damage the die and the underlying integrated circuit. Thus, it would be advantageous to have a heat spreader that is less likely to damage the die top when attached thereto.

Semiconductor device with tube based heat spreader


In a communication system (300), a controller interface (302) provides for monitoring of channel activity in order to determine communication devices (400) which are communicating using old encryption information. Upon a key management controller (306) determining that one or more communication devices are using an old encryption scheme, the key management controller (306) establishes communications with the communication device(s) (400) and provides them with the new encryption information.

During the process of providing communication devices such as radios with new encryption information using radio frequency (RF) transmissions ("over-the-air"), messages are sent to individual radios or groups of radios with the new programming information. A typical reprogramming sequence known as "rekeying" provides a radio with new encryption key(s) which the radio can begin to use in order to encrypt/decrypt future communication messages. With a communication key management controller providing new encryption information periodically, the security of communications between communication devices in the system is increased, since it would be futile for an eavesdropper to attempt to decode the encrypted transmissions given the fact that periodically the encryption scheme is changed.
During the process of reprogramming the radios during an encryption rekey sequence, if a radio is turned off, is out of range of the communication system, or is in a condition where the programming information can not reach the radio, that radio(s) would be unable to communicate with the rest of the communication system when the new encryption information goes into effect. Given the complexity of reprogramming radios over-the-air, there is a very good possibility that some number of communication units in the system will lose communications with the system due to some failure in the rekeying process as mentioned before.
Current over-the-air-rekeying (OTAR) systems attempt to compensate for this problem by sending the encryption information on a periodic basis to field units which have not acknowledged the initial rekey command. These re-try attempts are typically sent only a limited number of times and the duration of time between successive retries is usually increased, so that these retries do not increase the loading on the system. Unfortunately, this retry process does not assure that a field unit will be rekeyed promptly when it returns to an active service state (e.g., when it attempts to communicate with another unit). Furthermore, after the key management controller stops the retry process and no more retry attempts are sent, a field unit may have no chance of regaining entry into future encrypted communications.
In present communication system designs, the solution to the previously mentioned rekeying short comings is to increase the number and the frequency of the retries by the key management controller. This however has a negative impact on system capacity and interferes with future rekeying processes (e.g., if some radios have yet to be rekeyed from the previous rekey operation and new rekey sequence is now being sent out). Thus a need exists for a method and apparatus for providing new programming information such as encryption information to communication devices in a more efficient and timely manner.

Method and apparatus for over-the-air programming of communication devices


The present invention provides a local clean microenvironment near optical surfaces of an extreme ultraviolet (EUV) optical assembly maintained in a vacuum process chamber and configured for EUV lithography, metrology, or inspection. The system includes one or more EUV optical assemblies including at least one optical element with an optical surface, a supply of cleaning gas stored remotely from the one or more optical assemblies and a gas delivery unit comprising: a plenum chamber, one or more gas delivery lines connecting the supply of gas to the plenum chamber, one or more delivery nozzles configured to direct cleaning gas from the plenum chamber to a portion of the EUV assembly, and one or more collection nozzles for removing gas from the EUV optical assembly and the vacuum process chamber.

In order to keep pace with the ever increasing demand for smaller and smaller integrated circuit devices improved precision is needed in device fabrication and diagnostic tools. Extreme ultraviolet (EUV) lithography, EUV metrology and EUV inspection represent the next generation in integrated circuit processing and analysis technology, using 13.5 nm ultraviolet light. EUV light is highly absorbable by most media. For example, EUV light may be readily absorbed by a plasma light source used to generate the EUV light, an image mask, intervening air molecules and generally any other medium the EUV photons may encounter.
In order to mitigate the impact of EUV photon absorption, EUV lithography, metrology and inspection processes take place in a vacuum process chamber. Generally, an EUV optical system includes one or more highly reflective multilayer coated mirrors (e.g., molybdenum/silicon (Mo/Si) coated mirrors), which function as Bragg diffractors, reflecting EUV light at λ=13.5 nm via interlayer interference. In addition, these mirrored optical surfaces are occasionally coated with a protective layer, such as a protective layer of ruthenium (Ru) or some other type of protective cap layer, that is both highly reflective and resistant to oxidation. EUV photons or secondary electrons resulting from the emission process can contribute to contamination of optical surfaces in the vacuum process chamber through oxidation or carbonaceous growth on the mirrored optical surface. In addition, scattered radiation from the plasma source can induce outgassing from the vacuum chamber's internal surfaces and components. EUV mask inspection systems include various optics, sensors, adhesives, electric wiring, motors, and numerous other components. Although carefully screened for materials choices and cleaned to be compatible with ultra-clean vacuum (UCV), all these components will outgas. The residual contaminants, as a result of outgassing products, consist of many different contaminating compounds. In addition, residual gases may include hydrogen, oxygen, argon and xenon. Therefore, the UCV environment in a typical EUV mask inspection system will include background gas constituents containing these residual contaminants and gasses. For example, the resulting contaminants may include water molecules, light and heavy hydrocarbons, metal hydrides, inorganics, acids, bases, siloxanes, nitrides and other chemical compounds and species that can also interact with and contaminate optical surfaces.
To ensure maximum EUV inspection system optical throughput and uptime one must minimize the light intensity loss due to gas absorption and optical surface contamination. A UCV operating environment is preferred in EUV inspection systems. Specifically, UCV systems need to be ultrahigh purity with very low contaminants concentrations. UCV environments generally have lower impurity levels, thus require a much higher level of cleaning relative to ultrahigh vacuum (UHV) environments. For example, the partial pressures of contaminants such as hydrocarbons need to be at approximately ˜10−12 mbar, with water partial pressure below ˜10−7 mbar. In addition, the system can operate at relative high pressure compared to UHV. For example, the inspection system can operate at total pressures in the range of 0.1-10 Pa rather than low vacuum levels typical of ultrahigh vacuum (UHV) systems.
Either form of surface contamination, whether by oxidation, carbonaceous growth, or by other chemical species leads to increased absorption (and decreased reflection) of EUV photons, which in turn affects the uniformity of reflectivity throughout the given EUV optical system. For example, a typical EUV inspection, metrology or lithography tool typically requires reflecting EUV photons through a series of such mirrors, and even these highly reflective optical surfaces will reflect only 70% of EUV photons under optimal conditions. Therefore, even a minimal level of optical surface contamination, and the corresponding loss of reflectivity, can drastically impact the overall throughput of the EUV optical assembly. Maintaining optimal reflectivity throughout the system, and thus optimal throughput, requires the reduction and prevention of both oxidation, carbonaceous or other types of contamination growth on optical surfaces.
FIGS. 1A and 1B depict an optical assembly 100 with a small (˜25 mm diameter) multilayered Mo/Si mirror 16 or a large (˜250 mm diameter) multilayered Mo/Si mirror 22. Each mirror has a highly reflective optical surface 18 which may include an additional ruthenium capping layer. Incident EUV photons 12 strike the optical surface 18 and a majority of these EUV photons are reflected (14) by the optical surface 18. Absorbed EUV photons and secondary radiation contribute to the formation of contaminants 20 on the optical surface 18. It is, therefore, desirable to provide a method and system that cures the defects identified in the above prior art.

System and method for cleaning optical surfaces of an extreme ultraviolet optical system


Rigidity is improved at a part where side frame pieces overlap each other in a side frame. In a vehicle seat provided with a seat back frame, a side frame 10 of the seat back frame has a first side frame piece 20 and a second side frame piece 30 partially overlapping each other in a direction of extension of the side frame 10. The side frame 10 has an overlapping part 40 where both the first side frame piece 20 and the second side frame piece 30 overlap each other. At the overlapping part 40, the side frame pieces overlap each other in a state where a plurality of closed regions 41 and 42 closed by being surrounded by both side frame pieces are formed in a cross section of the overlapping part 40 intersecting with the direction of extension of the side frame 10.

In some conveyance seats provided with an inner frame, a side frame positioned in a side end portion of the frame is configured by a plurality of side frame pieces overlapping each other (see, for example, PATENT LITERATURE 1). In the seat device that is described in PATENT LITERATURE 1, the side frame of a seat back frame is divided into one upper frame piece and one lower frame piece and the upper and lower frame pieces partially overlap each other.
In a case where the plurality of side frame pieces constitute the side frame, an easy change in seat size is possible by the size of one of the side frame pieces being unified between products and the sizes of the remaining side frame pieces being changed between products. In other words, a flexible response to seat size variations is possible by the plurality of side frame pieces constituting the side frame.


A method and apparatus for reconstructing an image of an object using a three dimensional (3D) computerized tomographic (CT) imager having a cone beam radiation source and detector arrangement for acquiring measurement data. Before the acquisition of measurement data during an imaging operation of the apparatus, image reconstruction processing information dependant on the geometric parameters of the imager and required for processing of the acquired measurement data for developing contributions to the final reconstruction of the image, is pre-calculated and stored. During an imaging operation of the apparatus, the acquired measurement data is processed using the pre-calculated image reconstruction processing information for reconstructing the image.

1. Field of the Invention
The present invention relates generally to computed tomographic (CT) imaging apparatus that performs three-dimensional (3D) image reconstruction by processing cone beam measurement data representative of an object, and more specifically, to calculating and storing before imaging operation of the apparatus, image reconstruction information dependant on geometric parameters of the imaging apparatus and required for processing of the acquired measurement data in accordance with a cone beam image reconstruction algorithm. During imaging operation of the apparatus, use of the pre-calculated information greatly speeds up the run-time processing of the image reconstruction algorithm.
2. Description of the Background Art
Recently a system employing cone beam geometry has been developed for three-dimensional (3D) computed tomographic (CT) imaging that includes a cone beam x-ray source and a 2D area detector. An object to be imaged is be scanned, preferably over a 360.degree. angular range and along its length, by any one of various methods: i.e., by rotating the x-ray source in a scan path about the object while the object is being translated, by rotating and translating the source while the object remains stationary, or by rotating the object while one of the source or object is translated. These scanning techniques are all equivalent in that the position of the area detector is fixed relative to the source, and relative rotational and translational movement between the source and object provides the scanning (irradiation of the object by radiation energy). The cone beam approach for 3D CT has the potential to achieve 3D imaging in both medical and industrial applications with improved speed, as well as improved dose utilization when compared with conventional 3D CT apparatus (i.e., a stack of slices approach obtained using parallel or fan beam x-rays).
As a result of the relative movement of the cone beam source to a plurality of source positions (i.e., "views") along the scan path, the detector acquires a corresponding plurality of sets of cone beam projected measurement data (referred to hereinafter as measurement data), each set of measurement data being representative of x-ray attenuation caused by the object at a respective one of the source positions. After acquisition, the measurement data is processed for reconstructing a 3D image of the object.
As compared with the processing required for reconstructing an image when using an x-ray source supplying parallel or fan beams, the processing of the measurement data acquired when using a cone beam source is computationally much more complex. This is because when using a parallel or fan beam source, the measurement data is already directly representative of a 2D Radon transform of a cross-section of the object. However, this is not the case when using a cone beam source. Processing of the measurement data acquired using a cone beam source comprises:
1) conversion of the measurement data to Radon derivative data. This may be accomplished using the techniques described in U.S. Pat. No. 5,257,183 entitled METHOD AND APPARATUS FOR CONVERTING CONE BEAM X-RAY PROJECTION DATA TO PLANAR INTEGRAL AND RECONSTRUCTING A THREE-DIMENSIONAL COMPUTERIZED TOMOGRAPHY (CT) IMAGE OF AN OBJECT issued Oct. 26, 1993, hereby incorporated by reference,
2) conversion of the Radon derivative data to Radon data at polar grid points using, for example, the technique described in U.S. Pat. No. 5,446,776 entitled TOMOGRAPHY WITH GENERATION OF RADON DATA ON POLAR GRID POINTS issued Aug. 8, 1995, also hereby incorporated by reference, and
3) performing an inverse 3D Radon transformation of the Radon data using known techniques, such as those described in detail in the forenoted U.S. Pat. No. 5,257,183 for reconstructing image data that, when applied to a display, provides a view of the 3D CT image of the object.
As generally described in the forenoted U.S. Pat. No. 5,257,183, in order to provide a complete set of measurement data for accurate 3D (and even 2D) imaging of an object (or a region of interest in an object), it is necessary to satisfy completeness criteria. These criteria are well known, and are described in detail, for example, by Smith, B. D., in the publication "Image Reconstruction From Cone-Beam Projections, Necessary and Sufficient Conditions and Reconstruction Methods", IEEE Transactions Medical Imaging, MI-4 (1985), pp. 14-25. Basically, what is required is that any plane passing through the object or region of interest must intersect the scan path at one or more locations. The completeness criteria are also discussed in U.S. Pat. No. 5,383,119 entitled METHOD AND APPARATUS FOR ACQUIRING COMPLETE RADON DATA FOR EXACTLY RECONSTRUCTING A THREE-DIMENSIONAL COMPUTERIZED TOMOGRAPHY IMAGE OF A PORTION OF AN OBJECT RADIATED BY A CONE BEAM SOURCE issued on Jan. 17, 1995, hereby incorporated by reference. Additionally, this patent notes that the acquired data set is complete only if it can be processed so as to provide data at every point in the Radon space of a so-called "region of support". The "region of support" topologically corresponds to the field of view occupied by the region of interest of the object in real space. The Radon data is typically acquired by exposing the entire object within the field of view to an irradiating source.
As described in the forenoted U.S. Pat. No. 5,383,119, 3D image reconstruction techniques have difficulties imaging objects and regions which have a rather long or tall dimension. Generally, the detector must have a height and width large enough to cover the height and width of a projection of the object or region of interest on the detector, otherwise, some x-ray data would be missing. If the height or length of an object or region of interest is great, it is often impractical or difficult to obtain a detector array with sufficient height to obtain complete measurement data from the object or region of interest.
Sufficient filling of the Radon space by apparatus having various scanning trajectories (paths) and using an area detector which has a height that is less than the height of the region of interest being imaged are known for performing an exact image reconstruction. For example, in the above-noted U.S. Pat. No. 5,383,119, a rather complex technique is described for manipulating the acquired cone beam data so as to discard and recover data, as appropriate, so that only measurement data directly attributable to the region of interest is used for image reconstruction. In U.S. Pat. No. 5,463,666 entitled HELICAL AND CIRCLE SCAN REGION OF INTEREST COMPUTERIZED TOMOGRAPHY issued Oct. 31, 1995, hereby incorporated by reference, a cone beam CT imaging system is disclosed in which a region of interest portion of an object can be imaged without blurring or artifact introduction from imaging portions of the object not within the region of interest. A controllably movable source and relatively small area detector are controlled so as to define a scan path consisting of a central spiral portion having one circle portion at each end of the spiral portion which is level with upper and lower boundaries, respectively, of the region of interest. The switch from a spiral path to a circular path is necessary in order to obtain complete cone beam data at the upper and lower boundaries of the region of interest without blurring caused by imaging portions of the object that are outside the region of interest, as described in greater detail in the forenoted U.S. Pat. No. 5,463,666.
U.S. Pat. No. 5,463,666 also describes a data combination processing technique useful in a 3D CT imaging system having a relatively small area detector. Briefly, to determine the value of each point in Radon space, measurement data acquired from each of several different source positions must be individually processed, each individual processing contributing a fractional amount to the final determination of the value.
Although the techniques noted above describe the theory for exactly reconstructing an image using cone beam measurement data, a practical implementation of the processing turns out to be quite problematic. Not only is the amount of measurement data to be processed very large and rapidly acquired, but the calculations required on the acquired data are quite complex. For example, if one decides to reconstruct an object with 200.times.200.times.200=8.multidot.10.sup.6 (voxel=volume element of the object), for good quality one needs to obtain the object's 3-D Radon transform with a multiple (e.g., 4) amount of Radon samples, i.e., 32.multidot.10.sup.6 samples, and then perform the Radon inversion. The most computationally expensive part of the object reconstruction is the calculation of the Radon derivative date (step 1 noted above). As noted in detail in the forenoted U.S. Pat. No. 5,463,666, measurement data from several source positions typically contribute to each Radon sample by way of data combination, thus one needs to calculate about 100.multidot.10.sup.6 line integral derivatives. Each line integral derivative requires the calculation of 200.multidot.10.sup.6 single line integrals, since one uses the difference between two closely spaced line integrals to calculate a single line integral derivative. However, before one can perform these line integral derivative calculations, one has to compute for each Radon sample which source positions will provide the measurement data that must be processed, and determine the lines on the measurement data along which the integration must be performed. These latter determinations involve highly nonlinear calculations and are therefore computationally costly. In order to compute the contributing source positions, one has to intersect the source scanning path with the Radon integration plane as explained in the forenoted U.S. Pat. No. 5,463,666. When using a spiral scan path, this requires the solution of transcendental equations, which are computationally expensive. Furthermore, in addition to determining the lines on the measurement data along which the integration must be performed, one also has to calculate the appropriate end points of those lines for data combination purposes and region-of-interest masking. The complexity of these above-noted calculations leads to severe bottlenecks in processing of the measurement data, so as to prevent rapid and efficient image reconstruction.
Additionally, since image reconstruction requires processing of Radon space data, but the data being acquired during the imaging operation of the apparatus is cone beam projected measurement data, the run-time (imaging operation) processing of the measurement data results in fragmentary development of the Radon data, thereby adding further complexity to the already severe processing difficulties.
It would be desirable to provide a method and apparatus for processing of the cone beam measurement data in a manner that reduces the above described computational complexities and difficulties, thereby allowing a more efficient implementation of an exact cone beam reconstruction algorithm.
Although the above-noted problems are already known, so far experts have only devised techniques for reducing the amount of measurement data that is to be processed. For example, U.S. Pat. Nos. 5,461,650 and 5,333,164 by Kwok C. Tam are representative of some of these prior art techniques. U.S. Pat. No. 5,461,650 entitled METHOD AND SYSTEM FOR PRE-PROCESSING CONE BEAM DATA FOR RECONSTRUCTION FREE OF INTERPOLATION-INDUCED ARTIFACTS A THREE DIMENSIONAL COMPUTERIZED IMAGE, issued Oct. 24, 1995, is representative of "masking" techniques wherein the amount of measurement data that is required for image reconstruction processing is truncated by defining areas on the detector array from which measurement data is to be discarded. U.S. Pat. No. 5,333,164 by Mr Kwok Tam entitled METHOD AND APPARATUS FOR ACQUIRING AND PROCESSING ONLY A NECESSARY VOLUME OF RADON DATA CONSISTENT WITH THE OVERALL SHAPE OF THE OBJECT FOR EFFICIENT THREE DIMENSIONAL IMAGE RECONSTRUCTION, issued Jul. 26, 1994, is representative of techniques for truncating the image reconstruction processing by selectively retaining for further processing only those Radon data points that are in the objects' Radon region of support. Although such truncations of the measurement data or the Radon data points results in an overall improvement in the speed of reconstructing an image, they do so by discarding data so it is not processed, not by improvement in the speed or efficiency of the processing of the actual measurement data that develops contributions to the final reconstruction of the image.
It would be desirable to provide an improvement in the speed or efficiency of the actual processing of the measurement data that develops contributions to the final reconstruction of the image.

Pre-calculated hitlist for reducing run-time processing of an exact cone beam reconstruction algorithm


A wiring member which becomes substantially symmetrical on the plane of an electrostatic chuck unit is connected to the tip end of an RF introduction rod between the RF introduction rod and the electrostatic chuck unit in order to make uniform generation of an electric field due to bias RF which becomes a cause of plasma damage. The connection point between the electrostatic chuck unit and the wiring member may be single or plural.

1. Technical Field
The present invention relates to a plasma processing apparatus for processing an object to be treated, in particular a semiconductor wafer or a substrate for liquid crystal, a semiconductor manufacturing apparatus such as a high-density plasma (HDP) CVD apparatus, and an electrostatic chucking unit used for the corresponding semiconductor manufacturing apparatus.
2. Related Arts
Generally, a plasma etching apparatus, plasma CVD apparatus, ion implantation apparatus, sputtering apparatus, etc., are available as a plasma processing apparatus used for manufacturing semiconductor devices, liquid crystal display devices, etc. A high-density plasma (HDP)-CVD apparatus, which carries out CVD (chemical vapor deposition) by generating high-concentration plasma, of these plasma processing apparatuses is used for forming an interlayer insulation film, trench embedding film, or passivation film in a semiconductor apparatus.
Conventionally, this type of HDP-CVD apparatus is provided with a vacuum chamber into which a processing gas can be introduced and from which the inner gas can be discharged, and an RF coil disposed so as to surround the vacuum chamber. By driving the RF coil by an RF power source, high-density plasma is generated in the vacuum chamber. There may be cases where an electrostatic chucking unit (ESC) that electrostatically supports and fixes a semiconductor wafer, etc., which is an object to be treated, is disposed in the vacuum chamber of the HDP-CVD apparatus.
In Japanese Unexamined Patent Publication No. Hei-10-242244 (1st prior art), an HDP-CVD apparatus equipped with an electrostatic chucking unit (ESC) is disclosed. The HDP-CVD apparatus disclosed in the first prior art has a unipolar electrostatic chuck unit for attracting a semiconductor wafer or other substrate onto a surface of the dielectric film coated on the chuck unit by means of electrostatic attraction of an inductive charge. Where the electrostatic chuck unit is used, it is possible to dispose and treat two wafer sheets thereon. In detail, the electrostatic chuck unit disclosed in the first prior art is provided with a cylindrical chuck body formed of a dielectric and a dielectric layer formed on two circular regions of the chuck body opposed to each other. Also, at the same time, a water-cooling channel for cooling the chuck body itself and a helium channel for cooling the wafer are provided in the chuck body. Further, the chuck body is connected to a bias RF source by a power source line, and bias RF voltage is applied to the chuck body through the power source line, where charge plasma is generated in a processing area, and a wafer is electrostatically attracted onto and fixed on the chuck surface with electrostatic attraction of an inductive charge based on the charge plasma.
On the other hand, in the specification of Japanese Unexamined Patent Publication No. 2003-160138 (2nd prior art), an HDP-CVD apparatus is shown, which has an electrostatic chuck unit in the vacuum chamber thereof. The electrostatic chuck unit shown in the second prior art is provided with an ESC (electrostatic chuck structure) stage, an RF introducing rod, connected to the stage and the bias RF power source, which supplies bias RF from the bias RF power source to the ESC stage, and a bias RF wiring, extending from the RF introducting rod, which is connected to the ESC stage. In addition, where plasma processing is carried out by generating high-power and high-density plasma using the electrostatic chuck of the second prior art, it has been pointed out that unfavorable damage occurs in a substrate to be plasma-treated, for example, a semiconductor wafer, and as a result, product yield is remarkably lowered.
Herein, a detailed description is given with the HDP-CVD apparatus shown in the second prior art with reference to drawings. Referring to FIG. 1 and FIG. 2, the HDP-CVD apparatus shown therein is a processing portion of a cluster type vacuum processing apparatus. The processing portion has a vacuum chamber 10, and the vacuum chamber 10 has a ceramic dome 11 with an opening at its top and a channel body (lower chamber) 12 connected to the dome 11. The dome 11 and the channel body 12 define the interior space of the vacuum chamber 10.
A top coil 15 is disposed on the top of the dome 11. On the other hand, a side RF coil 16 is disposed sideways of the dome 11. Further, a side nozzle 18 for jetting a gas to the side of the dome 11 is provided inside the dome 11. With such a construction, plasma generating space is provided at the upper part of the dome 11, and processing space is provided at the lower part of the dome 11.
As illustrated, a ceramic plate (herein, A1N plate) 26, a heater plate 28 and a cooling plate 30 are laminated in this order and provided on the top coil 15 secured at the top portion of the dome 11. Also, a nozzle 32 is provided so as to protrude inside the dome 11 at the middle part of the top portion of the dome 11, and the nozzle 32 is connected to the top 02 line and top silane line, which extend through an opening formed between the cooling plate 30, heater plate 28 and ceramic plate 26. Also, the dome 11 and the entire members incidental thereto are enclosed by a lid cover 35. Further, the top coil 15 and side coil 16 are connected to the RF power source 36, and a source RF voltage is applied from the RF power source 36 to these coils 15 and 16.
On the other hand, a turbo pump 22 for exhausting air from the vacuum chamber 10 is connected to the bottom of the channel body (lower chamber) 12 via a slot valve 20 and a gate valve 21. In addition, a slit valve 24 and a remote plasma generator (applicator) 27 are provided at the side portion of the channel body 12.
Furthermore, a cathode body 40 for supporting and fixing an object to be processed (herein, a semiconductor wafer) is disposed in the processing space defined by the channel body 12 so as to be opposed to the top nozzle 32, and an electrostatic chuck unit 44 is installed in the processing space between the cathode body 40 and the side nozzle 18.
The electrostatic chuck unit 44 illustrated is electrically connected to the bias RF power source 42 secured outside the vacuum chamber 10, and a bias RF voltage of 13.56 kHz is supplied from the bias RF power source 42 to the electrostatic chuck unit 44 via a power supply shaft, that is, the RF introduction rod 46.
Herein, the electrostatic chuck unit 44 includes a supporting member 441 formed by a dielectric for supporting a substrate such as a semiconductor wafer and a conductive member 442 formed by a conductive material such as aluminum, and the conductive member 442 is connected to the RF introduction rod 46 via a wiring member 443. A combination of the electrostatic chuck unit 44, wiring member 443 and RF introduction rod 46 is herein called as an "electrostatic chuck member."
In the HDP-CVD apparatus thus constructed, when a bias RF voltage is supplied from the bias RF power source 42, charge plasma is generated, and the semiconductor wafer is electrostatically attracted on the upper surface of the electrostatic chuck by electrostatic attraction based on an inductive charge by the charge plasma and is fixed thereat.
Here, with reference to FIG. 2, a further detailed description is given of a construction of the electrostatic chuck unit 44 that composes the cathode body 40 used for a prior art plasma processing apparatus. FIG. 2 shows a connection between the electrostatic chuck unit 44 and the RF introduction rod 46 when the electrostatic chuck unit 44 is observed from the rear side of the cathode body 40. As illustrated, the RF introduction rod 46 is connected, at one point, to the conductive member 442 of the electrostatic chuck unit 44 by the wiring member 443.
However, the first prior art discloses only an electrostatic chuck unit having two electrostatic chucking surfaces and capable of processing two wafer sheets. It does not disclose any connection position, etc., between the electrostatic chuck unit and a power source line. Therefore, in the first prior art, no consideration is taken of distortion of an electromagnetic field based on an application position of the electrostatic chuck unit, to which a bias RF voltage is applied from the bias RF source, and influences thereof.
On the other hand, it has been pointed out, in the second prior art, that the electric field in the vacuum chamber is locally increased due to overlapping of the electric field based on the source RF output portion and the electric field generated in the application position of the bias RF in the ESC stage, whereby plasma is biased, and plasma damage is produced at a partial area of silicon wafer. Taking the same into consideration, the second prior art discloses that it is possible to mitigate plasma damage in wafer by determining the application position of the bias RF in the ESC stage at a position apart from the electric field based on the source RF output portion (that is, a position as far from the RF introduction rod as possible).
However, the second prior art only points out alternation of the positions of the source RF output portion and the bias RF application point. The second prior art does not disclose any means for making uniform the electric field inside the ESC stage.
Further, according to experiments made by the present inventor, as in the second prior art, it is made clear that only alteration of the connection position of the bias RF wiring connected to the RF introduction rod is insufficient to make distribution of the electric field in the vacuum chamber uniform.
Next, it is confirmed that, where, using a HDP-CVD apparatus shown in FIG. 1 and FIG. 2, a MOS transistor is produced on a semiconductor wafer incorporated in the electrostatic chuck unit 44, plasma damage is intensively generated at the connection part between the wiring member 443 for introducing bias RF and the electrostatic chuck unit 44, and in the vicinity thereof.
To make this clear, a description is given of the results of experiments in the case where a prior art plasma processing apparatus was used. First, a method for evaluating gate breakdown voltage using an antenna ratio has been known as a technology for evaluating plasma damage in a CVD apparatus. Herein, the antenna ratio expresses the ratio (SH/SG) of the area (SG) of a gate electrode of a MOS transistor formed as a device and the area (SH) of wiring connected to the gate electrode. Since the larger the antenna ratio becomes, the wider the area exposed to plasma becomes, deterioration of the gate breakdown voltage becomes remarkable. In addition, in a case of a device having a fixed antenna ratio, the higher the intensity of plasma is, the greater the deterioration of the gate breakdown voltage of the device becomes.
Using such an evaluation method, the gate breakdown voltage of the MOS transistor in a semiconductor wafer manufactured by a prior art HDP-CVD apparatus shown in FIG. 1 and FIG. 2 was evaluated, and the results shown in FIG. 3 were obtained. FIG. 3 shows the positions of the chips in the wafer which are subjected to plasma damage. For example, ▪ shows the chip which is subjected to plasma damage and whose breakdown voltage is 5 kV or low. In FIG. 3, the number of chips of ▪ is 17. Also, the number of chips whose breakdown voltage is 6.2 kV or low and larger than 6 is 36, for example.
As shown in FIG. 3, it has been found that, even in a case where the antenna ratio is comparatively small, for example, antenna ratio=5K, a number of chips which are subjected to plasma damage were produced, and the number of chips which are subjected to plasma damage was increased as the antenna ratio becomes larger and larger for 20K, 45K and 125K. Also, it is found that, where the connection position of the RF introduction rod 46 shown in FIG. 2 is taken into consideration, chips in which plasma damage occurred were unevenly generated at the connection position side by the wiring member 443 between the electrostatic chuck unit 44 and RF introduction rod 46. It can be presumed that this situation occurred due to strain in the electric field generated when closing the bias RF power source 42.

Plasma processing apparatus, semiconductor manufacturing apparatus and electrostatic chucking unit used thereof


A multi-level inverter topology is disclosed. A power converter circuit converts a DC source at its input to provide an alternating current (AC) at its output. The power converter circuit may have a controller operably attached to multiple series connections of switches. The controller may control one or more of the multiple series connections of switches to convert a DC input to provide multi-level AC voltages with DC offset across two terminals of the power converter circuit. The multi-level AC voltages with DC offset may then be converted by use of a plurality of series connections of switches to provide a single-phase AC voltage at a first output terminal with respect to at least one of a neutral potential, an earth potential, or a terminal of the power converter circuit.

A multilevel inverter is a power electronic device that is capable of providing a desired alternating current (AC) voltage level at its output. The desired AC voltage output is output by conversion of one or more input direct current (DC) voltage levels at the multilevel inverter input. A multilevel inverter with three or more output voltage levels may provide a combined voltage (Vout) at its output. Compared to an inverter with two levels of voltage combined together at its output, the combined voltage (Vout) of the multilevel inverter may have a lower differential change in voltage with respect to time. The lower differential change in voltage may therefore provide a lower harmonic distortion of the combined voltage (Vout). The lower harmonic distortion of the combined voltage (Vout) may therefore provide an increased smoothness of the combined voltage (Vout). Increased smoothness of the combined voltage (Vout) may be proportional to the increase in the number of output voltage levels. However, the smoother combined voltage (Vout) of the multilevel inverter may demand a controller with increased complexity. The increased number of output voltage levels may also further demand an increased number of components for the realization of the multilevel inverter. The increased number of components may include more switches when compared to the inverter with two levels of voltage combined together at its output. The inverter with two levels of voltage combined together at its output may require a controller with less complexity.