A ball grid array (BAG) package includes a substrate having a central aperture. Traces are coupled to a lower surface of the substrate. First ends of the traces support an electronic component in the central aperture. Interconnection balls are formed on second ends of the traces. The interconnection balls extend from the second ends of the traces, through the substrate, and protrude above a second surface of the substrate.

1. Field of the Invention
The present invention relates generally to the packaging of electronic components. More particularly, the present invention relates to a ball grid array package.
2. Description of the Related Art
Ball grid array (BGA) packages are well known to those of skill in the art. BGA packages contained an electronic component. The electronic component was mounted to a substrate. The bond pads of the electronic component were electrically connected to a plurality of solder balls, sometimes called interconnection balls, on a lower surface of the substrate of the BGA package. The solder balls were arranged in an array hence the name ball grid array package.
Advantageously, by arranging the solder balls in an array, a high density of interconnects could be formed in a relatively small area. For this reason, the BGA package became increasingly popular as the number of required interconnects to the electronic component increased.
However, as the art moved to smaller and lighter weight electronic devices, it became increasingly important that the thickness of the BGA package used within these electronic devices was small. Disadvantageously, the conventional BGA package was relatively thick. Accordingly, the conventional BGA package was not well suited for use with smaller and lighter weight electronic devices.
In accordance with one embodiment of the present invention, a ball grid array (BGA) package includes a substrate having a central aperture. Electrically conductive traces are coupled to a lower surface of the substrate. An electronic component is flip chip mounted to first ends of the traces by electrically conductive bumps, the traces supporting the electronic component in the central aperture.
Electrically conductive interconnection balls are formed on second ends of the traces. The interconnection balls extend from the second ends of the traces, through the substrate, and protruding above a second surface of the substrate.
Advantageously, the BGA package is relatively thin compared to prior art BGA packages. In particular, by mounting the electronic component in the central aperture, the thickness of the BGA package is minimized. Accordingly, the BGA package is well suited for use with miniature lightweight electronic devices, which require thin and lightweight BGA packages.
In accordance with an alternative embodiment of the present invention, a stacked BGA package includes an upper substrate having a first central aperture. Electrically conductive upper traces are coupled to a lower surface of the upper substrate, the upper traces comprising pinholes. A first electronic component is flip chip mounted to first ends of the upper traces by electrically conductive first bumps, the upper traces supporting the first electronic component in the first central aperture.
The stacked BGA package further includes a lower substrate having a second central aperture. Electrically conductive lower traces are coupled to a lower surface of the lower substrate. A second electronic component is flip chip mounted to first ends of the lower traces by electrically conductive second bumps, the lower traces supporting the second electronic component in the second central aperture.
Interconnection rods extend from the lower traces, through the lower substrate, through the pinholes, through the upper substrate, and to a height above an upper surface of the upper substrate.
Advantageously, since the interconnection rods pass through the pinholes, the interconnection rods are locked to the upper traces. Accordingly, the reliability of the electrical connection between the interconnection rods and the upper traces is extremely high. In this manner, the reliability of the stacked BGA package is maximized.
Further, the amount of area on the larger substrate, e.g., printed circuit mother board, allocated for interconnection with the stacked BGA package is reduced compared to mounting the first and second electronic components separately as separate BGA packages. Advantageously, the stacked BGA package in accordance with this embodiment of the present invention is well suited for use with smaller and lighter weight electronic devices.
These and other features and advantages of the present invention will be more readily apparent from the detailed description set forth below taken in conjunction with the accompanying drawings.


A process is provided for flash-spinning plexifilamentary fiber from pitch. The fibers can be stabilized and graphitized. The flash-spinning requires polyethylene amounting to 0.3 to 3.5% of the spin mixture (4 to 20% in the resultant fiber) for satisfactory plexifilament formation.

1. Field of the Invention
This invention relates to a process for converting pitch into fibers. More particularly the invention concerns a process for flash-spinning pitch into plexifilamentary fibers and the fibers produced thereby. The fibers, particularly those formed from mesophase-forming pitch, are suitable as precursors for "carbon" or "graphite" reinforcing fibers.
2. Description of the Prior Art
Processes for preparing carbon or graphite fibers of very high Young's modulus of elasticity and very high tensile strength are disclosed, for example, by Singer, U.S. Pat. No. 4,005,183, "High Modulus, High Strength Carbon Fibers Produced from Mesophase Pitch", and by Diefendorf et al, U.S. Pat. No. 4,208,267, "Forming Optically Anisotropic Pitches", which disclosures are hereby incorporated by reference. In these known processes the anisotropic or mesophase content of the pitch is increased to a concentration in the range of 40 to well over 90% by a first step in which a coal-tar or petroleum pitch is heat soaked or solvent extracted. Singer discloses heating the starting pitch in an inert atmosphere at temperatures in the range of 350.degree. to 450.degree. C. for a time sufficient to produce a pitch with a mesophase content in the range of 40 to 90%, the lower temperature requiring as much as a week and the higher temperatures, between 1-40 hours. Diefendorf et al discloses washing the starting pitch with solvent (e.g., benzene) and drying the benzene insoluble fraction. After the heat soaking or solvent extraction, fibers are prepared by (a) melting the thusly prepared mesophase pitch at a temperature in the range of about 340.degree. to 380.degree. C., (b) melt spinning, centrifugal spinning or blow spinning the molten pitch into fibers, (c) setting and stabilizing the fibers and (d) then graphitizing the fibers at a temperature in the range of 2,500.degree. to 3,000.degree. C. Generally, the fibers produced from molten pitch by the known processes (i.e., step b above) are very brittle and difficult to handle. Accordingly, it is an object of this invention to provide a process for preparing precursors for stabilization (i.e., step c above) that are less fragile and easier to handle than the precursor fibers of the known processes and to provide carbon fibers having a high surface area for use in absorption and filtration applications.
Techniques for flash-spinning synthetic, crystalline, organic polymers into fibers in the form of plexifilamentary strands are disclosed by Blades et al, U.S. Pat. No. 3,081,519. According to Blades et al, the crystalline polymer is dissolved in an organic solvent and then, at a temperature above the boiling point of the solvent and under at least autogenous pressure, the polymer solution is extruded through an orifice into a region of lower temperature and substantially lower pressure, whereby the solvent flash-evaporates and a plexifilamentary fibrous structure is formed and cooled. Among the many crystalline polymers disclosed as suitable for use in the process are polyethylene, polypropylene, polyhexamethylene adipamide, polycaprolactam, polyethylene terephthalate, etc. Polyhydrocarbons, such as polyethylene and polypropylene, are preferred. However, Blades et al does not disclose flash-spinning of non-crystalline materials, such as pitch, or the making of carbon or graphite fibers.


A cooling package in a power module comprises a first side for placing one or more semiconductor components; one or more holes for placing one or more magnetic components; and a second side with one or more connection parts. Therefore, all components of a power module which need to dissipate the heat have two thermal dissipation paths, therefore the heat inside the module can be greatly reduced.

In sealed environment, such as outdoor telecom radio units, the whole unit is water proof which means no fan inside the product, therefore the power module's heat dissipation path is the only conduction through heat sink. Consequently, most of power modules need de-rating over 50% current (As shown by FIG. 1) in sealed environment.
For high power stranded power module, there are two technical solutions that exist in the prior art, one is multilayer PCB (Printed Circuit Board) power module (As shown by FIG. 2), the winding for magnetic component 107 is designed in the multilayer PCB 101, and another one is aluminum base power module (As shown by FIG. 3), it has two-story structure, all discrete power semiconductor 201 and magnetic component 202 are mounted in aluminum base board 205, control circuit is in control board 207, there is multiple connection pin 206 to connect these two boards.
For multilayer PCB module, the top side is in contact with heat sink 102 for cooling by TIM (Thermal Interface Material) 103, input pin 104 and output pin 105 in bottom side is mounted to mother board 106 only for electrical connection. For aluminum base power module which is a two-story structure, power semiconductor component 201 and magnetic components 202 are mounted to aluminum plate 203 which can contact heat-sink 204 by TIM 205 for cooling, small pin 206 in aluminum plate 203 connects with control board 207 for communication, input pin 208 and output pin 209 are mounted with mother board 210 for electrical connection. For aluminum board 203, between aluminum base 211 and copper 212, there is TIM 213 inside, the lower the thermal resistance for TIM the higher the cost. Intension to increase power density, one way is increasing efficiency which is not economical and limited by electric technology; another way is minimizing thermal resistance with heat sink.
But both solutions have shortages, for PCB, and all components which need to dissipate the heat, including magnetic component, power semiconductor component, and controller, only have one cooling path which is used to conduct the heat to heat-sink by TIMs. The TIM is used for compensating the mechanical tolerance. Therefore, the module has very high thermal resistance in system, for sealed environment; there is no airflow inside. Consequently, the power module has to de-rate the output power a lot.


Packages and methods of formation are described. In an embodiment, a system in package (SiP) includes first and second redistribution layers (RDLs), stacked die between the first and second RDLs, and conductive pillars extending between the RDLs. A molding compound may encapsulate the stacked die and conductive pillars between the first and second RDLs.

Field
Embodiments described herein relate to semiconductor packaging. More particularly embodiments relate to fan out system in packages (SiPs).
Background Information
The current market demand for portable and mobile electronic devices such as mobile phones, personal digital assistants (PDAs), digital cameras, portable players, gaming, and other mobile devices requires the integration of more performance and features into increasingly smaller spaces. As a result, various multiple-die packaging solutions such as system in package (SiP) and package on package (PoP) have become more popular to meet the demand for higher component density devices.
System in package (SiP) structures typically include two or more dissimilar die in a single package as a functional system or sub-system. For example, logic and memory may be combined into a single package, along with other components such as passive devices, MEMS devices, sensors, etc. The die within a SiP can be stacked vertically or arranged horizontally on a carrier. The die are commonly connected with off-chip wire bonds or solder bumps. A SiP may be assembled on an interposer to fan out electrical terminals for an integrated product.
More recently, package on package (PoP) structures have become increasingly popular. PoP technology generally involves the installation of two or more packages on top of each other with a standard interface to rout signals between them. High component density devices may commonly have a memory package installed on top of a logic package or system on chip (SoC) package. Common PoP structures include an interposer between the top and bottom packages to fan out electrical terminals.

Fan out system in package and method for forming the same


An electric cable (2) includes a conductor (2a) which comprises a plurality of strands (21) and an insulation sheath (2b) which covers an outer periphery of the conductor (2a). An insulation displacement terminal (5) effects an insulation displacement connection with the conductor (2a) with the strands (21) being compressed into a slot width in which a contact resistance is in a stable area and the strands are not cut. The terminal (5) comprises: a slot (5a) having a given slot width (WS): a first pair of slopes (5b) opposed to each other and formed on an open part of the slot (5a) at an upper side with respect to an inserting direction of the electric cable (2), the first pair of slopes (5b) being adapted to guide the electric cable (2) into the slot (5a); and a second pair of slopes (5c) opposed to each other and formed on the open part of the slot (5a) at a lower side with respect to the direction of insertion of the electric cable. The second pair of slopes (5c) are adapted to compress and rearrange the strands (21) in the electric cable. The slot width (WS), an opening width (WS1) of the first pair of slopes (5b), an opening width (WS2) of the second pair of slopes (5c), an outer diameter (D) of the insulation sheath (2b) in the electric cable (2), and an outer diameter (d) of the conductor (2a) in the electric cable (2) are set to satisfy the following relationship: EQU WS1>D>d>WS2>WS; and 0.8.gtoreq.WS2/d.gtoreq.0.7.

This invention relates to an insulation displacement terminal which can effect stable insulation displacement connection with a conductor comprising a number of fine strands.
For convenience of explanation, a conventional insulation displacement terminal will be described below by referring to the drawings. FIG. 6A is a perspective view of a conventional insulation displacement terminal.
FIGS. 7A and 7B are graphs which illustrate relationships between a slot width and the number of cutoff strands and between the slot width and a contact resistance, respectively.
Heretofore, in order to connect a conductor in an electric cable, for example, a wire harness for an automotive vehicle or the like to a terminal in a manner of insulation displacement connection, an insulation displacement terminal 1, as shown in FIG. 6A, has been used which is provided with a slot 1a having a given slot width WS. The slot 1a in the insulation displacement terminal 1 is provided on an open part with a pair of slopes 1 b each having a wire (electric cable) guide angle a with respect to a longitudinal axis of the slot or a direction of insertion of the electric cable. Such an insulation displacement terminal requires a maximum force when an insulation sheath in the electric cable is stripped. This maximum force is called a stripping force for an insulation sheath.
In a design of the insulation displacement terminal, after a relationship between the wire guide angle a and the stripping force for insulation sheath has been found, the wire guide angle a is selected so that a force applied to the insulation displacement terminal or an insulation displacement tool becomes minimum. In order to maintain stabilization of insulation displacement connection of the conductor, the slot width SW is set so that the strands of the conductor are compressed without causing any cutoff of the strands, so that the strands behave as if they were a single wire as a whole, and so that the contact resistance between the conductor and the insulation displacement terminal becomes stable. That is, as shown in FIG. 7A, the slot width WS is designed so that no cutoff of the strands is caused and the contact resistance is in an allowable area of stabilization.
On the other hand, an electric cable to be used in movable parts in an apparatus which effects a sliding, rotating, or bending motion requires high flexibility. A conductor having a number of fine strands is suitable for satisfying such a requirement (hereinafter referred to a flexible conductor). Such a flexible conductor has a nominal cross sectional area and a number of strands, such as more than fifteen (15) in 0.3 mm.sup.2, more than nineteen (19) in 0.5 mm.sup.2, more than thirty (30) in 0.75 mm.sup.2, more than thirty-seven (37) in 1.25 mm.sup.2, or the like.
However, since the strands of the flexible conductor move irregularly and are not stable as a whole when a load is applied to the conductor, there is a problem in which the contact resistance is not stable, if a inflexible conductor having the same nominal cross sectional area is combined with a flexible conductor in which the contact resistance becomes stable in the slot width WS.
If the slot width WS is set to be narrower in order to make the contact resistance of the flexible conductor stable, a part of the strands are cut at the edges b on the intersections between the slopes 1b each having the wire guide angle a and the flat surfaces of the slot 1a when the conductor is inserted into the slot 1a, and thus the strands are not compressed fully. Consequently, a contact load between the strands or between the strands and the terminal does not become great and ultimately the contact resistance does not remain stable.
Even if the slot width WS is changed to find the stable area of the flexible conductor, as shown in FIG. 7B, the strands move irregularly and become unstable as a whole when the slot width WS is wide, while the stands are cut when the slot width is narrow. Accordingly, there is no slot width WS in which the contact resistance is in the stable area and the insulation displacement connection can not be effected.

Harness System Technologies Research, Ltd.


A polarizing filter includes a portion with a filtering layer having a plurality of openings extending therethrough, where this portion has a maximum physical thickness in a radiation travel direction which is less than approximately one wavelength of the radiation being filtered. A method of making the filter includes: forming a filtering layer over a substrate; creating a plurality of openings through a portion of the filtering layer; and separating the filtering layer from the substrate.

Detectors for infrared radiation or visible radiation typically include a substrate having on one side thereof a two-dimensional array of pixel detectors, arranged in rows and columns. In certain applications, it is desirable to polarize the radiation traveling to the pixel detectors. For this purpose, a micropolarizing filter can be provided over the array of pixel detectors.
A typical micropolarizing filter includes a rigid substrate having a thickness of approximately 600 microns, and a metal layer on one side of the substrate. The substrate is made of a material through which the radiation of interest can pass. For example, in the case of infrared radiation, the substrate can be gallium arsenide (GaAs). The metal layer can be any one of a number of different types of metal. The metal layer is typically a thin layer of gold, with a thickness of approximately 1 micron, and with a plurality of groups of parallel slots extending through it. Each group of slots corresponds to and is aligned with a respective pixel detector, and effects polarization of radiation traveling to that pixel detector. While pre-existing filters of this type have been generally adequate for their intended purposes, they have not been satisfactory in all respects.
For example, visible radiation and infrared radiation have wavelengths falling in a range from approximately 1 micron to 12 microns. Since the substrate is many times thicker than a wavelength of the radiation of interest, the substrate can produce undesirable optical effects. For example, the substrate typically causes a degree of scattering and/or defocusing of the radiation, such that a portion of the radiation traveling toward any given pixel detector ends up being misdirected toward one or more neighboring pixel detectors. As a result, there is a degree of optical cross-talk between the detectors. The large thickness of the substrate can affect the focal point of the detector front lens, and can also cause a significant degree of optical loss within the filter, such that the filter is not very efficient.
Another consideration is that the substrate has a relatively high index of refraction. Consequently, in order to achieve an effective degree of polarization, which is commonly known as a high extinction ratio, an anti-reflection (AR) coating is needed on each side of the substrate, and the pitch between the adjacent slots in the metal layer needs to be relatively small. In order to achieve a small pitch, fine lithography is needed for fabrication of the metal layer, which in turn increases the fabrication cost.
A further disadvantage of the relatively thick GaAS substrate is that it has limited optical transparency. Therefore, when the filter is being installed on a detector array, the detectors cannot easily be seen through the filter, and it is difficult to achieve accurate alignment between the filter and the detectors. In fact, it is fairly common to incur the cost and effort of using a laser to ablate alignment holes in the substrate, in order to be able to visually see through it for purposes of achieving accurate alignment with the substrate.

Thin micropolarizing filter, and a method for making it


A communications network comprising a cellular local area wireless network includes a plurality of access points connected to a housed computer and each other, and a plurality of mobile units each mobile unit being arranged for association with an access point. The mobile units are arranged to periodically scan for and identify the most eligible access point for association on the basis of the criteria of best quality signal strength and loading factor. In order to identify when mobile units are being removed from a predetermined area, access points having directional antennae are situated adjacent exit points to detect when mobile units are in a vicinity. Each mobile unit may include paging facilities, including the capability of transmitting information in a coded form known both to the unit and to a host, and power-saving facilities.

1. Field of the Invention
The invention relates generally to cellular networks. In particular the invention relates to a local area wireless network including a plurality of mobile units and a plurality of access points.
2. Description of the Related Art
Wireless local area networks (LAN'S) are used in business applications such as inventory, price verification mark-down, portable point of sale, order entry, shipping, receiving and package tracking. Such systems are often proprietary systems wherein the operator carries a mobile unit such as a hand-held computer communicating with a house computer via one of a plurality of access points connected to the house computer and to one another, each access point interacting with the house computer to create a wireless cell.
In order to achieve inter-operability of the various proprietary systems a draft standard IEEE 802.11 has been proposed (the IEEE 802.11 draft specification is available for public inspection).
The draft standard includes features such as 1 Mbps and 2 Mbps data rates, carrier sense multiple access/collision avoidance (CSMA/CA), a power-save mode for battery-operated mobile stations, seamless roaming in a full cellular network, high throughput operation, diverse antenna systems designed to eliminate "dead spots", and an easy interface to existing network infrastructures.
The term "roaming" relates to the scanning by each mobile unit of all access points to identify and associate with an eligible access point. Roaming between cells provides great flexibility and is particularly advantageous in locations that are difficult to wire, for simple relocation of work stations, and for portable work stations. The IEE 802.11 protocol supports either direct-sequence or frequency-hopping spread-spectrum systems, as well as infrared communications. Each access point executes a unique hopping pattern across 79 non-overlapping frequencies at a rate of one hop every 100 milliseconds, 66 hopping patterns being specified in the IEEE 802.11 draft standard and being selected to minimize the possibility of interference. Frequency hopping spread-spectrum systems are preferred by the majority of users as they allow increased capacity and decreased interference.
Although the IEEE 802.11 draft specification provides the basic packet types which can enable roaming it does not actually set the roaming algorithm. According to the draft specification the mobile unit determines the access point with which it will associate and the access point must accept the mobile unit unless it is defective or certain alarm conditions exist, such as memory full. There is, however, no suggestion of how, or by what criteria, other than those mentioned above, the mobile unit might select an appropriate access point, or the optimum access point.
U.S. Pat. No. 5,276,680 relates to a communication system including a plurality of portable units and a plurality of controllers wired to a network. Each portable unit polls all of the controllers to establish whether it can associate with any controller and receives a response from any controller having less than a predetermined number of portable units already associated therewith.

Power-saving arrangement and method for mobile units in communications network


An ultrasonic CMP polishing pad analyzer is disclosed. The analyzer provides a manufacturer or other user an ability to inspect a CMP polishing pad without removing the pad from the CMP machine by creating and displaying a topographical image of an in-service polishing pad. The analyzer includes an ultrasonic transducer and an analyzer body mounted to the CMP machine such that the ultrasonic transducer is positioned to receive reflected ultrasonic signals from a surface of the polishing pad.

Advances in electronic devices generally include reducing the size of the components that form integrated circuits. As semiconductor devices have become more highly integrated in recent years, circuit interconnections have become finer and distances between those circuit interconnections have become smaller. For example, in the case of photolithography, which can form interconnections smaller than 0.5 μm wide, surfaces on which pattern images are to be focused should be as flat as possible. Further, with smaller circuit components the value of each unit area of a semiconductor wafer becomes higher because the ability to use all of the wafer area for integrated circuit components improves. To properly form an integrated circuit that employs a much higher percentage of usable wafer area, contaminant particle counts on the semiconductor wafer surface must be reduced to very low levels. In order to clean a semiconductor wafer and remove unwanted particles, a process known as chemical mechanical polishing or chemical mechanical planarizing (hereinafter "CMP") has become popular.
The polishing is typically accomplished using a polishing pad attached to a platen surface of a CMP machine. A workpiece to be polished, such as a semiconductor wafer, is arranged in a manner such that a surface to be polished faces the polishing pad. The polishing pad and workpiece are independently rotated while an abrasive liquid or slurry is supplied onto the polishing pad. The workpiece is then pressed against the polishing pad at a predetermined pressure and the surface of the workpiece is polished to a flat mirror finish.
Polishing pads have a limited service life and become less effective over time. In turn, this results in inconsistent quality in the semiconductor wafers. As the polishing pad begins to lose its effectiveness, the semiconductor wafers polished later in the pad's life may be less smooth, possibly resulting in significant amounts of lost or unsaleable product. Thus, the polishing pads must be changed from time to time.
Current methods of determining the wear of a polishing pad, and thus whether the polishing pad is in need of replacement, are unsatisfactory. Analysis of the pad typically requires visual inspection. However, the pad usually cannot be visually inspected without removing the polishing pad from the CMP machine. Once removed, the polishing pad typically cannot be placed back on the machine, even if visual inspection determines some usable life remains. As a result, statistical analysis, based on experimental determination of pad wear over time under various operating conditions, is often used to make decisions about pad replacement. This is unsatisfactory for the reason, among others, that statistical analysis represents an average based on the wear of previous pads and is unable to account for any one particular pad or variations in quality or aberrant pads of inferior quality.
Furthermore, analysis of each polishing pad typically takes several hours or more and is often conducted by highly paid, highly skilled technicians whose time might be better used on other projects.
Another method of monitoring and analyzing polishing pad effectiveness is performing an analysis of the smoothness of the polished semiconductor wafer product. However, due to other steps required in wafer manufacture, this analysis is impractical until later in the manufacturing process. Thus, by the time defects in any one polishing pad are discovered and needed replacement is determined, the worn out pad may already have improperly polished many wafers remaining upstream of a suitable wafer analysis point, resulting in significant loss of product that must be discarded or recycled.
Conversely, using methods such as statistical analysis may also result in removing the polishing pad too soon, meaning that the full usable life of the polishing pad has not been obtained, resulting in the inefficient use of consumable materials. Thus, this also results in undesirable and uneconomic business practices.
What is needed is a system that can provide more efficient analysis of CMP polishing pads. What is also needed is a system that can analyze CMP polishing pads without removing the pad from the CMP machine.


A rotatable payload support turret for operation in a potentially hazardous environment includes a fixed element attached to a vehicle or fixed structure and a rotatable element, supported for rotation with respect to the fixed element. The turret includes a camera payload having a pointing direction configured to be upwardly pointing. An annular clearance gap formed between the fixed element and the rotatable element is sealed by a conventional gas tight magnetic fluid seal element. A wiper seal is also provided in the clearance gap between the location of the magnetic fluid and the external environment to prevent breakdown of the magnetic fluid by elements of the potentially hazardous environment. The clearance gap may also form a labyrinth seal having up to three legs that are oriented to oppose a gravitational force direction. In addition, the fixed element may include a fluid repelling feature for repelling streams of incoming fluids thereby deflecting elements of the potentially hazardous environment away from an outer opening of the clearance gap.

1. Field of the Invention
The invention provides a method and apparatus for sealing a rotary joint formed between a fixed element and a rotatable element. In particular, a rotary joint formed between a fixed member a rotating member includes a continuous annular clearance gap formed between the fixed member and the rotating member. The clearance gap is sealed to prevent environmental elements from penetrating the clearance gap by providing a combination of sealing elements and features, including a labyrinth seal configuration, a wiper seal and a conventional gas-tight fluid seal within the clearance gap. In addition, the fixed member include features for repelling damaging external environmental elements thrust upon it by wind or wave action.
2. Description of the Prior Art
Turret mounted airborne camera systems are used in military and public safety for search and rescue, surveillance and reconnaissance. Turret mounted airborne camera systems are also used by the news media for generating broadcast quality images. Airborne camera systems comprise a sensor payload having one or more radiation detecting sensors with each sensor having an associated optical system for forming an image of a scene or object onto the sensors. The payload may include one or more radiation emitters such as a laser, for laser range finding, or another radiation source for illuminating a scene or object at a desired spectral range. In general, each sensor or emitter system of the payload has a limited field of view for receiving radiation from or emitting radiation to and the limited field of view may be adjustable in size by increasing or decreasing optical magnification. A central axis of the field of view defines a pointing direction.
In one prior art example of an airborne camera configuration, manufactured by FLIR SYSTEMS of North Billerica Mass., (the assignee of the present invention), the sensor/emitter payload is housed within a sealed spherical, or ball, housing that includes one or more sealed apertures for receiving or emitting radiation therethrough. (See FLIR product Ultra 8500. ) The payload includes a visible light intensifying or low light visible camera, an infrared camera, and a laser illuminator. The pointing direction of each payload element is substantially pointed at the same location in a far field of the sensor/emitter system. The ball housing is supported by a motorized turret that rotates the ball about two axes for directing the pointing direction onto a desired target area. The turret is configured to rotate the payload ball by about 180 degrees in elevation to direct the pointing direction from an axis normal to the ground to an axis directed at either horizon. The turret is also configured to rotate the payload ball continuously in azimuth to direct the pointing direction over a 360 degree range. The example airborne camera system is available for mounting on a helicopter or a fixed wing aircraft. It is usually the case that such an airborne camera system is carried on the underside of the aircraft with the pointing direction being generally directed toward the ground during operation. While airborne camera systems are usually well protected from airborne environmental hazards such shock, vibration, high speed airflow, rain, extreme temperature variations and the like, airborne camera systems have heretofore been designed with a downward facing turret and ball assembly.
Recently, the demand for increased surveillance in many areas has lead to the need for camera systems of similar design and capabilities to be mounted on land and sea vehicles as well as onto fixed structures. In early attempts to meet these demands, standard turret mounted airborne camera systems have been mounted onto ships, land vehicles and fixed structures for land and sea based missions. However, in land and sea based applications, it is has nearly always been the case that the camera system is mounted on the topside of the vehicle or fixed structure with its turret and ball assembly facing upward. However, using a standard airborne camera with its turret and ball assembly facing upward has proved to be problematic. In particular, land and sea based camera systems have been damaged by environmental elements penetrating seals and contaminating the payload ball and the turret motor drive systems. Users of upward facing turret and ball assemblies have experienced contaminate penetration failures caused by wind blown sand and other particulate matter as well as rain on land, and by wind and wave driven water and salt fog or mist at sea. One reason for these failures has been shown to be that the upward facing turret is particularly susceptible to contaminates collecting in and filling the upward facing annular clearance gap between a fixed turret base and a rotating turret member. In particular, the turrets upward facing 360 degree azimuth rotation mechanism is susceptible to contaminate penetration. While the azimuth rotation mechanism of prior art camera systems include a conventional magnetic fluid gas-tight seals in its annular clearance gap, applicants have found that the fluid of the gas-tight seals breaks down quickly in the presence of environmental contaminates that make contact with the magnetic fluid. Since the azimuth rotary joint faces downwardly in airborne cameras, contaminants were unable to collect in the clearance gap and contact the magnetic fluid. However, when the clearance gap faces upward, there is a need to provide additional sealing in the gap to prevent environmental contaminates from coming into contact the magnetic fluid of the gas tight seal.
In one prior art example of magnetic fluid seal used in combination with another seal, U.S. Pat. No. 4,890,940 by Schmidt et al. teaches a ball bearing that includes a gas tight fluid seal formed between one end of an inner and an outer race of the ball bearing. The fluid seal comprises a magnet circuit for providing a flux path in which a magnetic fluid is contained within a thin an annular clearance gap formed between the inner and outer races. The magnetic fluid forms a gas tight seal between an internal bearing environment and an external environment. Schmidt et al. teach a pre-seal positioned between the fluid seal and the internal bearing environment for preventing bearing lubricant from mixing with the magnetic fluid and altering its magnetic properties. The pre-seal, taught by Schmidt et al., utilizes the continuous high rotational velocity of the bearing inner race combined with a particular shape of a pre-seal wall facing the inner race to generate a centrifugal force local to the pre-seal wall facing the inner race and the centrifugal force pushes lubricant away from the pre-seal. The pre-seal is also configured to provide an annular liquid trapping groove for trapping magnetic fluid that may become separated from the gas seal. While the pre-seal of Schmidt et al. includes features that help to keep the internal bearing lubricant separated from the magnetic fluid of the gas seal, the pre-seal of Schmidt et al. still leaves an unsealed annular gap between the rotating inner race and the fixed outer race and this gap may be penetrated by contaminants. Moreover, the pre-seal, of Schmidt et al., requires continuous high speed rotation to generate the centrifugal force necessary to repel bearing lubricant from the seal area. However, the azimuth rotation of the present invention does not rotate continuously nor does it rotate at high speed so that a pre-seal of the type taught by Schmidt et al. would be ineffective. Moreover, the pre-seal of Schmidt et al. is particularly designed for one contaminate, the bearing lubricant, which has known properties and the seal may not be affective in sealing the gap from a variety of contaminants having different properties. Accordingly, there is a need for a pre-seal that is usable for preventing a variety of contaminates having different properties from reaching a magnetic fluid used in a gas-tight magnetic seal when the rotation of the rotary joint is a not continuous and not at a high velocity.


A method for determining an effect of via/contact pattern density in via/contact etch rate of a wafer includes determining a neutral etchant species number flux intersecting each via/contact mouth as a function of local layout characteristics and determining variations in the neutral etchant species flux number as a function of the via/contact pattern density in a wafer scale. The comparison of these number fluxes provides the capability to discriminate an underetched or an overetched via/contact from normal vias/contacts satisfying an etch tolerance criterion. Chip designers can modify the layout design to minimize via/contact failures. Chip manufacturers can modify the etching process to minimize via/contact failures.

1. Field
The present invention relates to via/contact etch rates in semiconductor chip design and manufacturing, and more particularly to determining the via/contact pattern density effect in via/contact etch rate.
2. Related Art
Using a plasma etch process to create vias in the manufacturing of semiconductor chips is known in the art. Typically, based on currently employed dual-damascene technology metal lines are deposited with the electroplating process step into a dielectric layer previously patterned in the plasma etch process step. A patterned photoresist layer is deposited on top of the interlayer dielectric (ILD). Where the ILD is not covered by the photoresist, etchant from the plasma etches a feature. One of the most common integration schemes used today for 90 nm and 65 nm technological nodes is referred to as dual-inlaid "Via First Trench Last" (VFTL), meaning the via structure is etched before the trench. Ideally, the via is etched until an opening reaches an etch stop layer (dielectric barrier) previously deposited on the top of underneath metal layer. This barrier is etched (open) at the very last step in this VFTL scheme when the trench was etched, photoresist was striped, and the organic was removed. However, sometimes a via is over-etched or under-etched, affecting wafer yield. In an under-etch, the etching process stops before it reaches the etch stop layer, and inadequate electrical contact results. In an over-etch, the etching process continues even after it reaches the etch stop layer. This results in via CD widening, which can be responsible for the underneath metal line side-wall erosion. A similar situation takes place with the contact etch. The only difference is employment of silicide layers as etch stop layers and the absence of the trench etch step in process flow. A variety of control techniques are used for detection of the etch stop point to avoid the over-etch/under-etch. Aa an example of this technique we can mention an optical emission spectroscopy. When etch profile reaches the underneath etch stop layer, or silicide layer in the case of the contact etch, a sensing device detects a trace concentration of specific molecules in the gas phase and the etch process is terminated. Existing variation in etch rate can result in the situation that some of the vias/contacts will be still under-etched while some other already over-etched when the etch is stopped.
Variations in via/contact etch rates can result in the over-etch and under-etch of vias/contacts. This can be due to non-uniform via/contact density patterns on a wafer. FIGS. 1A–1B are simplified diagrams of a via layout on a wafer surface and a cross-section of vias in a via-layer, respectively. As illustrated in FIG. 1A, the vias are not uniformly distributed across a layout, leading to the microloading effect, which means a depletion in reactive gas species, which are needed for surface etching reactions (etchant), in the wafer regions where a higher etchant consumption occurs due to the greater via/contact density. This happens because of a reactant transport (by means of gas phase diffusion and flow) limitations which do not allow alleviation of concentration gradients over the length scale of the via/contact density variations. Additional variations in via/contact etch rates come from the neighbor features competiting for etchant species. As illustrated in FIG. 1B, when vias are close together, their respective regions of the surrounding gas phase, which supply etchant species for etching reactions, may overlap. These regions are restricted by the line of sight forming the solid angle from which the plasma bulk can be observed from the via inside. Because of a ballistic nature of the reactant transport, which takes place at the typical gas pressures used for plasma etch, only reactant located inside this solid angle can reach a corresponding feature and participate in etching reactions. These vias, characterized by overlapped gas phase "supply" regions should "share" reactants, that results in further reduction in etch rate. Local configuration in vias/contacts location strongly influences this overlap resulting in enhanced variations in etch rates. Some specific fragments of the via/contact layout can be responsible for creation of a strong reactant flux depletion resulting in severe via/contact under-etch.
Accordingly, there exists a need for a method for determining the effect of via/contact pattern density in via/contact etch rate. By determining this effect, chip designers can check the layout design regarding elimination of hot spots responsible for a prospective via/contact under-etch and modify it to minimize via/contact failures. Similarly, chip manufacturers can modify the etching process to minimize via/contact failures. The present invention addresses such a need.

Method for determining via/contact pattern density effect in via/contact etch rate


A method for visualizing and efficiently making comparisons of communication system performance utilizing predicted performance, measured performance, or other performance data sets is described. A system permits visualizing the comparisons of system performance data in three-dimensions using fluctuating elevation, shape, and/or color within a three-dimensional computer drawing database consisting of one or more multi-level buildings, terrain, flora, and additional static and dynamic obstacles (e.g., automobiles, people, filing cabinets, etc.). The method enables a design engineer to visually compare the performance of wireless communication systems as a three-dimensional region of fluctuating elevation, color, or other aesthetic characteristics with fully selectable display parameters, overlaid with the three-dimensional site-specific computer model for which the design was carried out.

1. Field of the Invention
The present invention generally relates to engineering and management systems for the design of wireless and wired communication systems and, more particularly, to a method for comparing the performance of wireless and wired systems in any environment (e.g., buildings, floors within a building, campuses, within cities, an outdoor setting, etc.) using a three-dimensional (3-D) visualization method.
2. Description of the Prior Art
As communication systems proliferate, radio frequency (RF) coverage within and around buildings, and radio signal penetration into and out of buildings, has become a critical design issue for communications engineers who must design and deploy cellular telephone systems, paging systems, or new wireless technologies such as personal communication systems (PCS), wireless local area networks (WLAN), and local multi-point distribution systems (LMDS). Emerging hand-held appliances will increasingly use wireless access methods, necessitating the need for tools and methods that allow technicians and engineers to rapidly install such wireless infrastructure. Also, the fiber optic and baseband networks needed to carry internet traffic will proliferate rapidly in the future, as well. In addition, RF networks involving micromachinery, RF identification tags, and optical communication links are of increasing interest due to the rapid miniaturization of communication devices and sensors, and the rapid proliferation of fiber optic bandwidth in and around campuses. Designers are frequently requested to determine if a radio transceiver location or base station cell site can provide adequate, reliable service throughout a room, a building, an entire city, a campus, a shopping mall, or any other environment. The costs of in-building and microcellular wireless communication devices are diminishing while the workload for wireless system design engineers and technicians to deploy such systems is increasing sharply. Given these factors, rapid engineering design and deployment methods accompanied by comprehensive system performance visualization and analysis methods are vital to wireless communication system designers.
In addition, recent research efforts by AT&T Laboratories, Brooklyn Polytechnic, and Virginia Tech are described in papers and technical reports entitled: S. Kim, B. J. Guarino, Jr., T. M. Willis III, V. Erceg, S. J. Fortune, R. A. Valenzuela, L. W. Thomas, J. Ling, and J. D. Moore, "Radio Propagation Measurements and Predictions Using Three-dimensional Ray Tracing in Urban Environments at 908 MHZ and 1.9 GHz," IEEE Transactions on Vehicular Technology, vol. 48, no. 3, May 1999 (hereinafter "Radio Propagation"); L. Piazzi, H. L. Bertoni, "Achievable Accuracy of Site-Specific Path-Loss Predictions in Residential Environments," IEEE Transactions on Vehicular Technology, vol. 48, no. 3, May 1999 (hereinafter "Site-Specific"); G. Durgin, T. S. Rappaport, H. Xu, "Measurements and Models for Radio Path Loss and Penetration Loss In and Around Homes and Trees at 5.85 GHz," IEEE Transactions on Communications, vol. 46, no. 11, November 1998; T. S. Rappaport, M. P. Koushik, J. C. Liberti, C. Pendyala, and T. P. Subramanian, "Radio Propagation Prediction Techniques and Computer-Aided Channel Modeling for Embedded Wireless Microsystems," ARPA Annual Report, MPRG Technical Report MPRG-TR-94-12, Virginia Tech, July 1994; T. S. Rappaport, M. P. Koushik, C. Carter, and M. Ahmed, "Radio Propagation Prediction Techniques and Computer-Aided Channel Modeling for Embedded Wireless Microsystems," MPRG Technical Report MPRG-TR-95-08, Virginia Tech, July 1994; T. S. Rappaport, M. P. Koushik, M. Ahmed, C. Carter, B. Newhall, and N. Zhang, "Use of Topographic Maps with Building Information to Determine Antenna Placements and GPS Satellite Coverage for Radio Detection and Tracking in Urban Environments," MPRG Technical Report MPRG-TR-95-14, Virginia Tech, September 1995; T. S. Rappaport, M. P. Koushik, M. Ahmed, C. Carter, B. Newhall, R. Skidmore, and N. Zhang, "Use of Topographic Maps with Building Information to Determine Antenna Placement for Radio Detection and Tracking in Urban Environments," MPRG Technical Report MPRG-TR-95-19, Virginia Tech, November 1995; and S. Sandhu, M. P. Koushik, and T. S. Rappaport, "Predicted Path Loss for Rosslyn, Va., Second set of predictions for ORD Project on Site Specific Propagation Prediction," MPRG Technical Report MPRG-TR-95-03, Virginia Tech, March 1995.
The papers and technical reports are illustrative of the state-of-the-art in site-specific radio wave propagation modeling. While most of the above papers describe a comparison of measured versus predicted RF signal coverage and present tabular or two dimensional (2-D) methods for representing and displaying predicted data, they do not report a comprehensive method for visualizing and analyzing wireless system performance. The "Radio Propagation" and "Site-Specific" papers make reference to 3-D modeling, but do not offer novel display methods or graphical techniques to enable a user to visualize signal coverage or interference in 3-D. Furthermore, there do not exist effective methods that allow a wireless communications technician or designer to rapidly display predicted performance values, or to compare, through visualization, differences in predicted performance values between alternate network design concepts within a particular specified environment.
Common to all wireless communication system designs as well as wired network designs is the desire to maximize the performance and reliability of the system while minimizing the deployment costs. Ways to minimize cost include the use of computer aided design tools that manage many aspects of the design process. Such tools also help create methods that enable the engineer or technician to work quickly. Consider a wireless system, for example. Analyzing radio signal coverage and interference is of critical importance for a number of reasons. A design engineer must determine if an environment that is a candidate for a wireless system contains too much noise or interference, or if the existing wireless system will provide sufficient signal power throughout the desired service area. Alternatively, wireless engineers must determine whether local area coverage will be adequately supplemented by existing large scale outdoor wireless systems, or macrocells, or whether indoor wireless transceivers, or picocells, must be added. The placement of these cells is critical from both a cost and performance standpoint. The design engineer must predict how much interference can be expected from other wireless systems and where it will manifest itself within the environment. Prediction methods which are known to the inventors and which are available in the literature provide well accepted methods for computing coverage or interference values for many cases. However, the implementation of such models are generally very crude, and rely on cumbersome spreadsheets, or inefficient operating platforms in research laboratories with little support and little visualization capability. Inevitably, performance measurements must be made in the environment of interest in order to generate the proper prediction models, or to at least verify the chosen prediction models for acceptable accuracy or reliability.
Depending upon the design goals, the performance of a wireless communication system may involve a combination of one or more factors. For example, the total area covered in adequate received signal strength (RSSI), the area covered in adequate data throughput levels, and the number of customers that can be serviced by the system are among the deciding factors used by design engineers in planning the placement of communication equipment comprising the wireless system. Thus, maximizing the performance of a wireless system may involve the complex analysis of multiple, potentially unrelated factors. The ability to display the results of such analysis in a manner easily interpretable by design engineers is invaluable in wireless system deployment. Three dimensional (3-D) visualization of wireless system operating parameters provides the user with rapid assimilation of large data sets and their relation to the physical environment. As wireless systems proliferate, these issues must be resolved quickly, easily, and inexpensively, in a systematic and repeatable manner.
There are many computer aided design (CAD) products on the market that can be used to design a computerized model of an environment. WiSE™ from Lucent Technology, Inc., SignalPro™ from EDX, PLAnet™ by Mobile Systems International, Inc., (later known as Metapath Software International, now part of Marconi, P.L.C.) and TEMS from Ericsson, Wizard by Safco Technologies, Inc. (now part of Agilent Technologies, Inc.), are examples of CAD products developed to aid in the design of wireless communication systems.
Lucent Technology, Inc., offers WiSE™ as a design tool for wireless communication systems. The WiSE system predicts the performance of wireless communication systems based on a computer model of a given environment using a deterministic radio coverage predictive technique known as ray tracing.
EDX offers SignalPro® as a design tool for wireless communication systems. The SignalPro system predicts the performance of wireless communication systems based on a computer model of a given environment using a deterministic RF power predictive technique known as ray tracing.
Mobile Systems International, Inc., (now a part of Marconi, P.L.C.), offers PLAnet™ as a design tool for wireless communication systems. The PLAnet system predicts the performance of macrocellular wireless communication systems based upon a computer model of a given environment using statistical and empirical predictive techniques. Ericsson Radio Quality Information Systems offers TEMS™ as a design and verification tool for wireless communication indoor coverage. The TEMS system predicts the performance of indoor wireless communication systems based on a building map with input base transceiver locations and using empirical radio coverage models.
The above-mentioned design tools have aided wireless system designers by providing facilities for predicting the performance of wireless communication systems and displaying the results in the form of flat, two-dimensional grids of color or flat, two-dimensional contour regions. Such displays, although useful, are limited by their two-dimensional nature in conveying all nuances of the wireless system performance. For example, slight variations in color present in a two-dimensional grid of color, which may represent changes in wireless system performance that need to be accounted for, may be easily overlooked. Furthermore, as wireless systems proliferate, the ability to visually predict and design for coverage and interference is of increasing value.
Common to all communication system designs, regardless of technology, size or scale, is the need for measurement data at some point in the design process. For environments which are candidates for wireless communication systems, it is essential to first conduct a measurement campaign to determine spectral occupancy, noise levels, interference levels, or available channels.
Whether in the initial design stage or the final verification stage, or during ongoing maintenance during the lifecycle of a communication system, no communication system is implemented without the input and use of measurement data. However, measurement acquisition within in-building environments is much more tedious and time consuming than in the macrocellular environment where measurement acquisition is carried out using Global Positioning System data to determine the location of the measurement being taken. Global Positioning System (GPS) data, which so many RF engineers have come to rely upon for outdoor measurement acquisition, is not an option for microcell environments in most cases, and is extremely difficult to use reliably within buildings, due to the clutter and resulting attenuation of the GPS satellite signal levels within urban areas and within manmade structures. While new methods, such as the Qualcomm SnapTrack indoor GPS system may offer long-term promise for in-building location, today's readily available GPS solutions are expensive and are seldom available to engineers or technicians tasked with the deployment, measurement, or optimization of in-building or microcell networks. Therefore, recording real-time measurement data within a building becomes a laborious, time-consuming task involving scratched notes and blueprints and manual data entry which are both expensive and ineffectual in many respects.
In addition to measuring RF signal properties from emitted base transceivers there is also a need to measure data throughput time in computer data networks. Throughput time is the time required to transfer a record or file of known size from one computer to another. In order to standardize the measurement of data throughput time for comparison or verification purposes, files of a set size (e.g., 100K) are used and transferred in packet sizes such as 512 bytes. Similar to RF signal attenuation, data throughput time, and each of a many number of other important network measurement parameters, such as packet latency, bit error rate, packet error rate, and bit rate throughput, is also a function of transmission distance and signal obstruction (e.g. walls, doors, partitions), as well as multipath propagation and the specific radio modem design.
Presently, there are no known effective visualization techniques that allow an engineer or wireless technician to display measurement results or rapidly compare, through visualization, various measurement results of various performance measurements of a particular communication network, or collection of networks, within a particular specified environment over time, frequency, or space. Various signal property measurement acquisition tools and systems have been developed to aid in the design of wireless communication systems such as PenCat™, Walkabout PCS™ and TEMS Light.
LCC International Inc. offers the PenCat™ as a pen-based collection and analysis tool for wireless communication design that runs on a small hand-held tablet computer. The PenCat™ system enables a user to roam about a building, take signal property measurement data at a location in the building using a receiver linked to the tablet computer, and link the measured data to that building location on a computer map representing the building by tapping the appropriate portion of the map on the computer screen with a stylus pen. The building map can be entered into the PenCat™ system by either scanning blueprints, sketching the building within the application, or importing from another source. PenCAT uses two dimensional bit maps to model the building environment. Safco Technologies, Inc. (now part of Agilent Technologies, Inc.) offers the Walkabout PCS™ system as a portable survey coverage system for use in indoor or outdoor wireless communication system design. Similar to PenCat™, the Walkabout PCS™ system utilizes a hand-held computer linked to a receiver for measuring signal properties at a given location and linking the measured property data to that location represented on a stored computer map. Also similar to the Safco Walkabout is the Agilent 74XX indoor measurement system, which also uses a bitmap floor plan. Ericsson Radio Quality Information Systems offers the TEMS Light system as a verification tool for wireless communication indoor coverage. The TEMS Light system utilizes a Windows-based graphical interface with two dimensional bit map drawings on a mobile computer linked to a receiver to allow a user to view a stored building map, make location specific data measurements, and link the measured data to the represented location on the stored computer map. Unlike other in-building communication measurement systems, InFielder™ by Wireless Valley Communications, Inc. merges measurement data with periodic updates of position location on a three-dimensional model of the physical environment. The InFielder™ product concept is disclosed in U.S. patent application Ser. No. 09/221,985 filed Dec. 29, 1998, and the contents of this application are herein incorporated by reference. However, as originally disclosed in the aforementioned patent application, InFielder, does not offer an efficient method for rapidly viewing and comparing measurement data in a 3-D environment such that measurement values, and comparisons of measurement values, may be quickly determined and inferred by the user.

System and method for efficiently visualizing and comparing communication network system performance


According to one embodiment, an etching solution used for etching of silicon nitride is provided. The etching solution includes phosphoric acid, an acid, silicic acid compound, and water. The phosphoric acid has a first acid dissociation exponent pKa1. The acid has an acid dissociation exponent smaller than the first acid dissociation exponent pKa1. A mass ratio M1/M2 of mass M1 of the phosphoric acid to mass M2 of the acid having the acid dissociation exponent smaller than the first acid dissociation exponent pKa1 is within a range of 0.82 or more and 725 or less.

In recent years, in the manufacture of a semiconductor device, a technique for selectively removing silicon nitride from a substrate including silicon oxide (SiO2) and silicon nitride (Si3N4) is demanded.
As such a technique, wet etching using a phosphoric acid aqueous solution is widely used. In this wet etching, the above-described substrate is immersed in a phosphoric acid aqueous solution warmed to approximately 150° C. for a certain time.
In this wet etching, the increase of the ratio of the etching rate of silicon nitride to the etching rate of silicon oxide, or the selection ratio is demanded. As a method for increasing the selection ratio, wet etching using a mixed solution including sulfuric acid, phosphoric acid, and water is studied.

Etching solution, etching method, and method for manufacturing an electronic component


Systems and methods for semiconductor fabrication management. A processing unit receives an engineering change request (ECR) comprising information regarding new engineering for a wafer lot, generates an ECR reminder comprising information regarding the ECR request, transmits the ECR reminder to a client operator through a communication device, receives a reply corresponding to the ECR reminder, determines a reply result indicating whether the ECR is accepted by detecting the reply, and transmits the reply result to a manufacturing execution system (MES).

The invention relates to fabrication management technology, and more particularly, to fabrication management methods and systems responding to engineering changes.
A conventional semiconductor factory typically includes the requisite fabrication tools to process semiconductor wafers under operations, such as photolithography, chemical-mechanical polishing, or chemical vapor deposition. During manufacturing, the semiconductor wafer passes through a series of process steps, which are performed by various fabrication tools. For example, in the production of an integrated semiconductor product, the semiconductor wafer passes through up to 600 process steps. Costs for such automated production are influenced to a great extent by the question as to how well and efficiently the manufacturing process can be monitored or controlled, so that the ratio of defect-free products to the overall number of products manufactured (i.e., yield ratio) achieves as great a value as possible.
Changes in process flow, operating recipes, or others, may improve yield during semiconductor manufacturing. These engineering changes are typically applied to specific wafer lots after confirmation from client operators. Conventionally, operators spend much time communicating various engineering changes to relevant clients, and even more time managing responses thereto. This labor-intensive management method severely hinders efficiency.

Fabrication management systems and methods

Taiwan Semiconductor Manufacturing Co., Ltd.


A light source, particularly suited for surgical and other medical illumination applications, includes an electrodeless lamp assembly, a reflector having the electrodeless lamp assembly mounted therein and high frequency power source for supplying high frequency power to the electrodeless lamp assembly. The electrodeless lamp assembly includes an electrodeless high intensity discharge lamp capsule including a light transmissive discharge envelope enclosing a discharge volume containing a mixture of starting gas and chemical dopant material excitable by high frequency power to a state of luminous emission. The luminous emission has a color rendering index greater than 85 and preferably has a color rendering index greater than 90. The luminous emission preferably has low energy in the spectral range of 800 to 1000 nanometers relative to energy in the visible spectral range. The electrodeless lamp assembly further includes at least one electric field applicator for coupling high frequency power to the lamp capsule.

The need for improved medical examination and surgical lamps is driven by surgeon and operating room nurse preferences for superior illumination during modern surgical procedures, which frequently take many hours. Examples of such time-intensive procedures are limb reattachments in post trauma situations, open heart surgery and organ transplants. Shadow-free illumination of deep body cavities is required to eliminate eye strain and fatigue of the operating staff. It is also important to minimize downtime of the lamps and to simplify maintenance.
Surgeons respond in part to color characteristics of the body parts being observed. However, perceived color is influenced by the illuminating light. There is therefore a need for surgical lamps having high color rendering values. Also, surgeons must look closely at small body parts and into narrow cavities. There is therefore a need for a high level of illumination. For similar reasons, there is a need for lamps with acceptable color temperature, which can be moved and directed at will (universal burn position) and which provide shadow-free illumination of the operating zone. Long lamp life is also important.
The light source is commonly focused on the patient, thereby heating the operating area. Prolonged or high level heating of the patient can be injurious. There is therefore a need for a surgical lamp that minimizes temperature rise in the operating area, while delivering superior illumination.
A surgical lighting system has a stringent set of requirements. It must provide a high light level to the operating area with a spectral distribution and intensity that both supports the surgeon in his or her task, yet is not detrimental to the patient. There should be no dark shadows in the operating area, and the patient's tissue, organs and blood should be illuminated with the correct color. The perception of the smallest tissue features during the surgical procedure can be important. Sometimes the surgeon wants to see into deep body cavities, so light should come from many directions. Tissue desiccation can become an issue as body tissues exposed during surgery rapidly lose moisture. Consequently, the patient must not be excessively radiated with infrared energy which would dry the tissue. The radiant energy in the spectrum between 800 and 1000 nanometers should be kept to a minimum, as this is a spectral band of absorption by tissue and water, and contributes nothing to visual perception. Yet this spectral band is present in almost all conventional sources.
As shown in FIG. 8, the light from the surgical illuminator, for general surgery, should have color coordinates that fall within an area described by a five-sided polygon 400 on the 1931 CIE Chromaticity Diagram. Correlated color temperatures within this polygon range from 3500K to 6700K, but the color temperature of the surgical illuminator is nominally preferred to be at 4500K. A color rendering index (CRI) greater than 85 and preferably greater than 90 is required for this light source. In addition, the specific saturated red color rendering index (R9), which is not included in the computation of general CRI should be high, for example, above 60.
Surgical light sources should be flicker-free and have the ability to maintain their color properties for any lamp position. These requirements have been the major impediments to the introduction of electroded metal halide lamps into the surgical lighting area. Surgical illumination requires instant hot restart or operation of a backup illumination system following a short power interruption. Lamp life should be in excess of 1000 hours. Tungsten halogen lamps used in critical surgical applications usually undergo periodic preventive replacement. Surgical lamps must also be explosion-proof and free of electromagnetic interference (EMI), as the lamps operate in close proximity to explosive gases and highly sensitive electronic monitoring equipment.
In prior art surgical illuminators, a light source is placed inside a large area polygon reflector to direct light to the operating area from as large a spatial angle as possible. This has the advantage of reducing shadowing in the operating area by the surgeon's head and shoulders. Typically, a tungsten halogen lamp is used. Significant light filtering is necessary to eliminate the sizable component of infrared radiation generated by a tungsten halogen lamp. The infrared light filter also color corrects the tungsten halogen lamp by suppressing some red radiation to produce a higher color temperature. The normal color correction of tungsten halogen lamps then has a tendency to reduce the saturated red, or R9, index, which can affect viewing.
Electrodeless high intensity discharge (EHID) lamps have been described extensively in the prior art. In general, EHID lamps include an electrodeless lamp capsule containing a volatilible fill material and a starting gas. The lamp capsule is mounted in a fixture which is designed for coupling high frequency power to the lamp capsule. The high frequency power produces a light-emitting plasma discharge within the lamp capsule. Recent advances in the application of high frequency power to lamp capsules operating in the tens of watts range are disclosed in U.S. Pat. No. 5,070,277, issued Dec. 3, 1991, to Lapatovich; U.S. Pat. No. 5,113,121, issued May 12, 1992, to Lapatovich, et al.; U.S. Pat. No. 5,130,612, issued Jul. 14, 1992, to Lapatovich et al.; U.S. Pat. No. 5,144,206, issued Sep. 1, 1992, to Butler et al.; and U.S. Pat. No. 5,241,246, issued Aug. 31, 1993, to Lapatovich, et al. As a result, compact EHID lamps and associated applicators have become practical.
The above patents disclose small, cylindrical lamp capsules wherein high frequency energy is coupled to opposite ends of the lamp capsule with a 180.degree. phase shift. The applied electric field is generally colinear with the axis of the lamp capsule and produces a substantially linear discharge within the lamp capsule. The fixture for coupling high frequency energy to the lamp capsule typically includes a planar transmission line, such as a microstrip transmission line, with electric field applicators, such as helices, cups or loops, positioned at opposite ends of the lamp capsule. The microstrip transmission line couples high frequency power to the electric field applicators with a 180.degree. phase shift. The lamp capsule is typically positioned in a gap in the substrate of the microstrip transmission line and is spaced above the plane of the substrate by a few millimeters, so that the axis of the lamp capsule is colinear with the axes of the field applicators.
Electrodeless high intensity discharge lamps for use in automotive illumination systems are disclosed in the aforementioned U.S. Pat. Nos. 5,070,277 and 5,113,121 and in U.S. Pat. No. 5,299,100 issued Mar. 29, 1994 to Bellows et al. These systems require good light quality, reliability and long life, but are not required to provide exceptional color rendering. Consequently, the use of sodium scandium chemistry is common in EHID automotive headlamps, with general color rendering indexes of about 60-70. Thus, prior art EHID lamps have not met the requirements discussed above for surgical illumination.
Electrodeless lamps are also disclosed in U.S. Pat. No. 5,508,592 issued Apr. 16, 1996 to Lapatovich et al; U.S. Pat. No. 5,498,937 issued Mar. 12, 1996 to Korber et al; U.S. Pat. No. 5,498,928 issued Mar. 12, 1996 to Lapatovich et al; U.S. Pat. No. 5,471,109 issued Nov. 28, 1995 to Gore et al; U.S. Pat. No. 5,448,135 issued Sep. 5, 1995 to Simpson; U.S. Pat. No. 5,359,264 issued Oct. 25, 1994 to Butler et al; U.S. Pat. No. 5,339,008 issued Aug. 16, 1994 to Lapatovich et al; and U.S. Pat. No. 5,280,217 issued Jan. 18, 1994 to Lapatovich et al.

Electrodeless high intensity discharge medical lamp


A fire-fighting monitor includes a body that has a fluid passageway and an inlet and an outlet. The inlet is adapted to mount to a base on a fire truck, and the body is configured so that the outlet is rotatable about a vertical axis over a 360 degree range of motion. In addition, the body is configured such that the outlet is rotatable about a horizontal axis over one range of motion of about 195 degrees in one form and about 270 degrees in another form.

The present invention relates to a firefighting monitor and, more specifically, to a firefighting monitor that is particularly suitable for use with fire trucks, including aircraft rescue firefighting (ARFF) trucks.
An ARFF truck is a special category of firefighting truck that is used to respond to aircraft ground emergencies. Like most fire trucks, an ARFF truck has an articulating boom with a monitor mounted to the end of the boom and also another monitor mounted at its bumper. The boom monitor is typically used to provide a water, chemical, or foam attack from a raised position above the aircraft, while the bumper monitor is typically used to provide a water, chemical, or foam attack from the under belly of the aircraft. The greater the speed of delivery of the fluids or foam, the better the outcome.
While attempts have been made to increase the size of the monitors and thereby increase the flow of the fluid or foam, with increased size typically comes increase in weight and cost to manufacture.

Elkhart Brass Manufacturing Company, Inc.


A detection unit is disclosed for arrangement in the main magnet of an MR device, which has both an RF transceiver system and a PET detector. In at least one embodiment the RF transceiver system is divided into two parts and the two parts are arranged upstream and downstream of the PET detector in the longitudinal direction of the patient tunnel. The RF transceiver system and PET detector are applied to the same image volume. In at least one other embodiment, an MR device is equipped with the detection unit, and in at least one other embodiment, a method operates the detection unit.

Magnetic resonance tomography (MR or MRT) is an imaging method for displaying tissue in the human or animal body. MRT is based on the principle of nuclear spin resonance, in accordance with which atomic nuclei such as the hydrogen nuclei present in large numbers in the body exhibit a magnetic moment. They can thereby be excited with electromagnetic radiation in the radio frequency region (RF radiation) in an applied external magnetic field, and emit this radiation shortly thereafter. This RF radiation is detected with an antenna that mostly also generates the exciter pulse; this is why use is made of the term RF transceiver system, or RF coil, for short.
The magnetic field is mostly generated by a superconducting main magnet that is integrated in a field generating unit that encloses a horizontal patient tunnel into which the patient to be examined is pushed. The main magnetic field then runs parallel to the longitudinal direction of the tubes, in the so called z direction.
The resonant frequency of the atomic nuclei is directly proportional to the applied main magnetic field. Consequently, the spatial coding inside an image volume is achieved by virtue of the fact that so called gradient fields are applied in addition to the main magnetic field during the measurement; these are briefly applied magnetic fields with as linear as possible a gradient in the x, y or z directions. The gradient fields are mostly generated by specific gradient coils that are arranged inside the field generating unit.
A further medical imaging method is positron emission tomography (PET). As a nuclear medicine method, PET is suitable, in particular, for displaying biochemical processes in the body, for example for finding tumors and metastases. In this case, the patient is administered a tracer with a radionuclide that is distributed in the body and emits radioactive radiation in the form of positrons in the process. After a short time, the positrons decay into two opposite gamma quanta that are captured by suitable detectors. These are mostly arranged around the body as an annular PET detector. For example, the photons are captured by a matrix, made from scintillation crystals, in which each photon produces a scintillation upon striking. Said scintillation is, in turn, captured and amplified by photodetectors, for example by photomultiplier tubes or avalanche photodiodes.
Interest has recently been taken in combining MRT and PET with one another in one device in order to be able to apply the two imaging modalities simultaneously or shortly after one another to the same patient. This requires arranging the two units of MR-RF transceiver system and PET detector required for data acquisition inside the (mostly superconducting) main magnet and MR gradient coil.
In an obvious solution, to this end a PET detector is inserted into the patient tunnel of the field generating unit of an MR device, and, in turn, an RF transceiver unit is inserted into the PET detector ring. However, this arrangement is problematic, since the RF coil and PET detector exert a negative mutual influence: the currents inside the PET detector generate interference fields that are captured by the RF coil and can lead to interference signals. Since it is arranged between the examination region and the PET detector, the RF coil, in turn, can lead to scattering of gamma quanta and thus reduce the sensitivity of the PET detector. Moreover, nesting the RF coil and PET detector ring from the inside to the outside strongly reduces the inside diameter remaining for the patient inside the main magnet, and this can, in particular, result in the measurement being incapable of being carried out given a patient who is claustrophobically disposed or overweight.
An example of an MR device in which a PET detector is arranged between the gradient coil and the RF transceiver system is illustrated in FIG. 2. FIG. 2 shows a longitudinal half of the field generating unit 9 of an MR device, with further components integrated therein, in cross section. The dashed and dotted line 2 represents the middle line of the substantially tubular field generating unit 9. Permanently integrated in the field generating unit 9 is a gradient coil 3 that is likewise approximately tubular and that has coils for generating x, y and z gradients.
Inserted into the gradient coil 3 is a PET detector ring 4, an RF shield 6, a support tube 5 and an RF transceiver system 7. The RF shield 6 ensures that the RF fields are shielded against the PET ring during excitation of the RF coil 7. The RF coil 7 is provided with a cladding 8 against the examination region and/or patient tunnel 13.
The design illustrated in FIG. 2 therefore has the advantage that a whole body examination is thereby possible. The designation "body coil" is also used for an RF coil 7, integrated permanently in the main magnet 9, according to FIG. 2, which permits excitation and detection over the entire examination region.
On the other hand, the arrangement illustrated in FIG. 2 has the abovementioned disadvantages, for example it diminishes the onion skin type design of the patient tunnel. In order still to enable a sufficiently large inside diameter, the distance between the RF shield 6 and the RF conductor structures that is required for the formation of the field return space and thus for a good quality of the RF coil 7 must be strongly reduced inside the coil 7.

Detection unit including an RF transceiver system and a pet detector


A system, method and article of manufacture are provided for the automatic recovery from errors encountered during an automated Licensed Internal Code (LIC) update on a storage controller. The present invention functions with a concurrent or nonconcurrent automated LIC update. The automated recovery from many error conditions is transparent to the attached host system and on-site service personnel, resulting in an improvement in the LIC update process.

Computing systems often include one or more host computers (hosts) for processing data and running application programs, direct access storage devices (DASDs) for storing data, and a storage controller for controlling the transfer of data between the hosts and the DASD. Storage controllers, also referred to as control units or storage directors, manage access to a storage space that often comprises numerous hard disk drives. Hosts may communicate Input/Output (I/O) requests to the storage space through the storage controller.
To maintain availability in the event of a failure, many storage controllers provide redundant hardware clusters. Each hardware cluster comprises a processor complex, cache, nonvolatile storage (NVS), and separate power supplies. The NVS in one cluster backs up write data from the cache in the other cluster so that if one cluster fails, the write data in the cache of the failed cluster is stored in the NVS of the surviving cluster. After a cluster fails, all I/O requests would be directed to the surviving cluster. When both clusters are available, each cluster may be assigned to handle I/O requests for specific logical storage devices configured within the physical storage devices.
It is necessary to periodically update the software on each of the clusters of the storage controller. Multiple hardware devices within each of the clusters may need software updates resulting in a complicated and time consuming process. This process is typically done manually by qualified service personnel. When problems are encountered during the update process the service personnel may have to perform repair actions and then start over with the software update process. This adds further to the time to update the software and may contribute to increased downtime for the storage controller. Frequently errors encountered during the LIC update result in returning to the beginning of the update process after a repair action. This adds further to the time required to perform the LIC software update and contributes to increased unavailability of the storage controller, directly impacting customer satisfaction and access. There is a need for an automated system that automatically recovers from errors and resumes operation of the LIC update process at an appropriate point in the LIC update process.

Automated error recovery of a licensed internal code update on a storage controller

International Business Machines Corporation


This invention relates to methods for testing elongation and cracking of coating arrays. The method includes simultaneously applying an elongating force to each of a plurality of coatings, and monitoring the cracks and thickness decrease in each coating. A relative performance characteristic of each coating is then determined based on a correlation between a detected crack and/or thickness decrease in the coating, and the corresponding elongating force.

This invention relates to a method for determining mechanical properties of coating arrays. More particularly, the invention allows for the characterization of elongation and cracking of small-size coatings arranged in an array format.
Elongation properties of a coating material are of importance for automotive, telecommunication, and other applications. Conventional methods of elongation measurements involve the use of a large size coating material of about 100 mm in width and 150 mm in length, application of a conical mandrel test apparatus followed by a visual inspection of crack formation and measurement of the distance from the farthest end of the crack to the small end of the mandrel. The disadvantages of this standard method are the need to use a large coating area to obtain measurable parameters, manual measurements, difficulties in evaluation of several coatings simultaneously, and low sensitivity of measurements. A variety of test methods for elongation have been reported. These include the use of a CCD camera to measure the distance between the grid lines and calculate the elongation, automatic tensile test devices, devices to measure elongation due to bending under load, the use of lasers for noncontact elongation measurements and for the enlargement of the measuring range of speckle measuring systems of elongation.
Unfortunately, these techniques do not provide the capabilities for measurements of a large number of small-size coatings. What is needed are devices and methods for determining a variety of mechanical properties of multiple coating arrays. Such applications are of interest in combinatorial development of coating formulations and coatings.
The present invention solves the above-described problems by providing methods for testing elongation and cracking of coating arrays. In one embodiment, the method comprises simultaneously applying an elongating force to each of a plurality of coatings, and monitoring for a decrease in coating thickness and/or for cracks in each of the coatings. A relative performance characteristic of each coating is then determined based on a correlation between a measured decrease in coating thickness and/or a detected crack, and the corresponding force.
In another embodiment, the method comprises applying a plurality of coatings to a plurality of substrates wherein each coating is applied to a different substrate. The substrates are secured in a test arrangement and a force is applied to the substrates in order to bend the coating on each substrate. A detection system is then used to visualize cracks in the coatings and/or any decrease in coating thickness.
In still another embodiment of the present invention, the substrates are made of a deformable material. The substrates are preferably in the form of a geometrical shape having a curved surface. The force applied to the substrates modifies the shape of each substrate, thereby causing the coating on the substrate to bend and produce cracks. A detection system is used to visualize the cracks in the coatings and/or a decrease in coating thickness.
A further embodiment comprises applying at least one coating to a substrate, and forming the substrate into at least one coil having a specific diameter. A detection system is then used to visualize any cracks in the coating and/or a decrease in coating thickness.
Further aspects and advantages of the present invention will be more clearly apparent to those skilled in the art during the course of the following description, references being made to the accompanying drawings which illustrate some preferred forms of the present invention and wherein like characters of reference designate like parts throughout the drawings.

Elongation and cracking testing and optical characterization of small-size coatings and materials


The invention relates to a method of modeling reference data in an information system (IS), characterized in that it is based on a Unified Modeling Language (UML) model of reference data for the IS listed in deposits of application data for the IS. Any reference data in the IS is defined by a specialized concept inheriting the characteristics of a generic concept. The method comprises steps in which the following actions are carried out:                grouping the concepts into categories according to logical criteria;        building a categories diagram in which the categories are grouped according to a predefined typing of categories, wherein the categories are related to each other by UML dependence relations, each materialized in one reference data;        making groups of generic concepts in the same category consistent with deposits of application data in the IS by applying the principle according to which reference data defined by specialized concepts inheriting generic concepts in a same category and possessing an identical specialization necessarily belong to the data deposit of a unique application; and        defining a direction for UML dependence relations relating the said categories to each other, the said direction of UML dependence relations depending firstly on typing of categories, and secondly on the deposit of the reference data containing the relation.

1. Field of the Invention
This invention relates to a method of modeling reference data in an information system (IS) and an algorithm based on this modeling in order to localize deposits of reference data for an information system.
Therefore, the invention relates to the domain of software techniques.
2. Description of the Related Art
In an organization, an IS is composed of the set of all elements that contribute to the processing and circulation of information in the organization (database, application software, procedures, documentation, etc.) including the information system itself (central processing unit, peripherals, operating system, etc.). Therefore, the IS is composed of the human and technical means necessary for the storage and processing of information in an organization.
An IS is modeled in the IS design phase and it consists of creating a virtual representation of processes used by businesses in an organization and information stocks and flows providing input to these processes.
One known method called MERISE is the most widespread method used for designing an information system. It is a computer analysis method dedicated to setting up an IS. The MERISE method is based on separation of data and processing to be done in several conceptual and physical models. Among these models, the Conceptual Data Model (CDM) is used to set up a clear representation of IS data and defines functional dependences of these data between themselves. The purpose of the CDM is to formally write data that will be used by the IS. Therefore, it is an easily understandable representation of data used to write the IS using entities. An entity is the representation of a material or immaterial element that plays a role in the system that is to be described. Entities of the same type, in other words with the same definition, are grouped within a set called an entities class. Semantic links may exist between several entities. Thus, relations are defined to represent these semantic links and a relation class contains all relations of the same type (therefore that connect entities belonging to the same entity classes).
However, data modeling proposed in a Conceptual Data Model originating from the MERISE method cannot be used to translate the concept of the reference value of a data item or a reference relation between two items of data.
The concept of IS reference data relates to data produced by an application that supplies official values for these data. This concept of reference data is extremely important in an IS, particularly when it is required to create or update the urbanism of an IS. Data are often manipulated through several applications and their values can thus be modified by the different players involved in the IS. Moreover, if an IS is to remain efficient or if its services are to be improved, it must necessarily progress at the same rate as the organization develops and its strategy changes. Urbanism work then consists of defining the main lines of these developments and continuous changes, and setting up a simpler interconnection between the different systems and applications of the IS.
In this context, the concept of a reference value for a data item or a relation between two data items is very important to optimize urbanism of an IS. Each application of an IS that has reference data in its data deposit must be capable of offering these reference data to client applications. Obviously, this concept of a data offer by a supplier to customers has an influence on the functional urbanism of the IS.
The Conceptual Data Model derived from the MERISE method is incapable of representing homogenous data groups or dependence relations between these groups, although these are useful for representing the concept of reference. This method does not enable construction of a model using principles based on IS reference data and is therefore limited in terms of optimizing the functional urbanism phase of an IS.
Moreover, modeling of data proposed in a Conceptual Data Model derived from the MERISE Method is also limited in that it cannot locate deposits of reference data for new data in an IS. However, this is a very important characteristic necessary to optimize urbanism of an IS.
Thus, considering the above, one purpose of this invention is to propose a method for modeling data of an IS that overcomes the disadvantages of prior art as mentioned above, and particularly that is capable of defining a diagrammatic representation of the concept of a reference value of a dependence relation between two items of data and data themselves.
Another purpose of this invention is to propose a method for localizing deposits of reference data for new data in an IS, to support principles of the proposed modeling method, that determines which data deposit contains a reference data item, in other words the particular application responsible for the data.

Method of modelling reference data and use of this method for localization of reference data in an information system