A screening machine on a frame with a hopper having a conveyor belt. The conveyor belt discharges particulate material poured into the hopper into a rotating barrel screen or vibrating planar screen for sifting the material. A hammermill apparatus is pivotably mounted on a hood member to an arm that is pivotably mounted to the frame of the machine. The hammermill is positioned above the conveyor belt at the discharge end. The hammermill can pivot upwardly relative to the arm upon striking a large object on the conveyor belt, and a spring mounted to the arm and the hood biases the hammermill back to its original position. A hydraulic ram is drivingly linked to the arm for manually or automatically displacing the hammermill relative to the conveyor belt.

1. Field of the Invention
This invention relates generally to an apparatus for separating according to size a quantity of particulate material that contains various sizes of particles, and more particularly relates to an apparatus with at least one moving screen that separates particulate material according to size by the particulate falling through the screen or screens.
2. Description of the Related Art
Moving screens are used to sort material by size in various industries including mining, construction, waste disposal, landscaping and demolition. Some screens are substantially planar and vibrate at least partially in a direction transverse to the plane of the screen. Material placed on the screen vibrates with the screen and the particles that are smaller than the openings in the screen fall through and collect beneath the screen or are conveyed to a location spaced from the screen, such as by a chute and/or conveyor belt.
Other screens are not planar but are cylindrical, and these screens are called barrel or "trommel" screens. Barrel screens have at least one screen that is cylindrically shaped to form a cage-like screening structure. The barrel screen's longitudinal axis is angled relative to horizontal during use, and the barrel screen is rotated about its longitudinal axis. The material to be processed is placed in the open mouth of the higher end and the rotation and the angled axis cause the material to tumble toward the lower end with smaller, screened material falling down through the apertures of the screen. The material that does not pass through the screen is discharged out of the open mouth of the lower end. The screened material can accumulate on the ground below the barrel screen or can fall onto a conveyor belt or chute that is positioned to catch the material and convey it out from beneath the screen. Likewise, the material that passes out of the lower end of the barrel screen can fall on the ground or be conveyed away on a chute or conveyor belt.
A typical barrel screen apparatus has a barrel screen with a length that is greater than its diameter, and a conveyor belt that is aligned lengthwise beneath the barrel. The lengthwise conveyor extends out the front or the rear of the apparatus, or a lateral conveyor receives the material from the lengthwise conveyor and conveys it laterally at any position intermediate the two ends of the apparatus or at one of the two ends. Other barrel screen apparatuses have different barrels and permit the screened material to fall onto the ground below the barrel.
Portable barrel screening machines are known in the prior art. Conventional portable barrel screening machines have an input conveyor, a rotary barrel screen and a longitudinal conveyor beneath the barrel screen, all of which are mounted together on frame. The frame is provided with wheels at one end and a "fifth wheel" at the opposite, for connection to a conventional semi-tractor vehicle or is mounted on tracks. Other conventional barrel screening machines have a planar screen followed by a first conveyor that receives the material that passes through the planar screen, a barrel screen that receives the material from the first conveyor and a second conveyor that receives the material that falls through the barrel screen and conveys it away from the barrel.
The material that is to be screened by conventional machines is typically fed into the receiving end of a barrel screen by a conveyor belt, onto which material is dumped. The material that is first poured onto the conveyor is not always processed prior to entering the barrel screen. If the material is processed before entering the barrel screen, it is processed by a large planar screen or a hammermill, followed by a conveyor that conveys the pre-screened material into the barrel screen as described above.
The prior art configurations have the disadvantage that the length required for the apparatus is large. If the material is not pre-processed, the barrel screen must be very long to sufficiently screen the charge of particulate. Alternatively, if the material is pre-processed by a planar screen or a hammermill, the entire apparatus is especially long due to the second conveyor's length. These long machines cannot be transported easily over the road. Therefore, the need exists for a screening machine that is effective, but can be transported easily.


A material scrap submergence device comprises a body (10) of heat resistant and/or a refractory material that includes a side wall (12) and a base (14) that define a submergence chamber (10). The refractory body (10) can include passages (24) that receive rods (22). The rods (22) can place the refractory body (10) under compression. In another embodiment, the body is confined by a frame (72) attached to the body. The submergence chamber (10) can also be used as a gas injection chamber.

In the recycling of metals, aluminum scrap pieces are melted for treatment and processing. A large portion of the aluminum scrap pieces are thin walled as a result of the mechanical shaping action from which they were formed. Melting thin walled scrap pieces is difficult because rapid submergence in molten metal is severely hampered since thin walled scrap pieces tend to float on molten metal. Unfortunately, extended exposure to the hostile atmosphere in a traditional melting furnace results in extremely high oxidation loss.
In a typical melting operation, a melting furnace is provided with an enclosed hearth and a connected open sidewell. Usually the sidewell is divided into a pump well and a melting bay. A pump or other molten metal flow inducing apparatus is positioned in the pump well and pumps molten metal from the hearth to the melting bay. Sometimes the melting bay is further divided into a chargewell and a drosswell. Metal scrap pieces are fed into the melting bay, particularly the chargewell.
A variety of apparatus have been used in the melting bay, specifically in the chargewell, to facilitate the submergence of the scrap metal below the surface of the molten metal bath. Three major types of systems exist. The first type includes mechanical systems constructed primarily of a rotor that creates a molten metal flow from the top surface. The second type of system uses a mechanical device to physically push the scrap below the melt surface (elephant feet/well-walkers). The third type of system relies on the shape of the chamber to create a metal flow that submerges scrap pieces in the chargewell. Particularly, the flow of molten metal into the chargewell is manipulated in such a manner to achieve a vortex that draws chips from the top surface into the bath.
In known systems that rely on the shape of the chamber to create a metal vortex flow, the chargewell is typically made of a refractory material. Significant stress is imparted on the chargewell because the temperature of the molten metal inside of the chargewell is very high and the lower portion of the chargewell is typically submerged in the furnace while the upper portion of the charge well is not. This can create a large temperature gradient between the refractory material in the lower portion of the chargewell and the refractory material in the upper portion of the chargewell. In addition, the forces created by the high speed metal circulation impart stresses on the chamber walls. Since the chamber is often an integral component of the furnace, repair of the walls, or in fact even cleaning, can be a difficult and expensive undertaking, particularly in the form of furnace downtime.

This patent is subject to a terminal disclaimer.


A single latch circuit is coupled to each bit line in a multiple level cell memory device to handle reading multiple data bits. The circuit is comprised of a latch having an inverted node and a non-inverted node. A first control transistor selectively couples the non-inverted node to a latch output. A second control transistor selectively couples the inverted node to the latch output. A reset transistor is coupled between the inverted node and circuit ground to selectively ground the circuit when the transistor is turned on.

Memory devices are typically provided as internal, semiconductor, integrated circuits in computers or other electronic devices. There are many different types of memory including random-access memory (RAM), read only memory (ROM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), and flash memory.
Flash memory devices have developed into a popular source of non-volatile memory for a wide range of electronic applications. Flash memory devices typically use a one-transistor memory cell that allows for high memory densities, high reliability, and low power consumption. Common uses for flash memory include personal computers, personal digital assistants (PDAs), digital cameras, and cellular telephones. Program code and system data such as a basic input/output system (BIOS) are typically stored in flash memory devices for use in personal computer systems.
As the performance and complexity of electronic systems increase, the requirement for additional memory in a system also increases. However, in order to continue to reduce the costs of the system, the parts count must be kept to a minimum. This can be accomplished by increasing the memory density of an integrated circuit.
Memory density can be increased by using multiple level cells (MLC). MLC memory can increase the amount of data stored in an integrated circuit without adding additional cells and/or increasing the size of the die. The MLC method stores two or more data bits in each memory cell.
A multilevel cell has multiple Vt windows that each indicate a different state as shown in FIG. 1. Multilevel cells take advantage of the analog nature of a traditional flash cell by assigning a bit pattern to a specific voltage range stored on the cell. This technology permits the storage of two or more bits per cell, depending on the quantity of voltage ranges assigned to the cell.
For example, a cell may be assigned four different voltage ranges of 200 mV for each range. Typically, a dead space or margin of 0.2V to 0.4V is between each range. If the threshold voltage of the cell is within the first range, the cell is storing a 11. If the threshold voltage is within the second range, the cell is storing a 10. This continues for as many ranges that are used for the cell. MLC requires tight control of the threshold voltages in order to use multiple threshold levels per cell.
One critical parameter of MLC flash memory integrated circuits is the transistor count of the sense amplifier that is used to read the programmed values in the cells. The high parallelism of flash memory devices requires that the same sense amplifier data latch be used at least one for each bit line being read out of the array. This problem is worse for MLC devices since the circuits need to handle two bits from each bit line. This greatly increases the number of transistors required for read-modify-write operations.
Due to intense competition and consumer desire for longer battery life in electronic devices, manufacturers must constantly find ways to reduce the quantity of components in devices while maintaining reliability. For the reasons stated above, and for other reasons stated below that will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for reducing the quantity of transistors required in sense amplifier data latches in MLC memory devices.

Single latch data circuit in a multiple level cell non-volatile memory device


A reactor having a shell comprising one or more reactor tubes located within the shell, said reactor tube or tubes comprising a plurality of catalyst receptacles containing catalyst; means for providing a heat transfer fluid to the reactor shell such that the heat transfer fluid contacts the tube or tubes; an inlet for providing reactants to the reactor tubes; and an outlet for recovering products from the reactor tubes; wherein the plurality of catalyst receptacles containing catalyst within a tube comprises catalyst receptacles containing catalyst of at least two configurations.

The present invention relates to a process for carrying out equilibrium limited reactions in the presence of a heterogeneous catalyst. More particularly, it relates to a process in which the temperature is controlled and the process is optimised. Still more particularly, it relates to a process for producing sulphur trioxide.
Many chemical reactions are reversible. In these reactions the forward reaction of the reactants to the desired product is accompanied by a reverse reaction in which the desired product reverts to the reactants. These processes will reach equilibrium where the rate of forward reaction matches the rate of the reverse reaction. Such reactions are said to be equilibrium limited.
There are a large number of reactions which fall into this category. An often used example to illustrate an equilibrium limited reaction is the oxidation of sulphur dioxide to form sulphur trioxide which proceeds in accordance with the equation:SO2+½O2↔SO3
In an equilibrium reaction of this type, there is an equilibrium constant Kc which is normally expressed as the ratio of the concentration of the product to the starting material.
The oxidation of sulphur dioxide is a highly exothermic reaction and from the Van't Hoff equation it is possible to understand the dependence of the equilibrium constant on the temperature of the reaction. Typically Van't Hoff equation is expressed as:
      ln      (            K     1             K     2          )    =                    -      Δ                     H      r             R             (               1             T       2                -           1             T       1                   )      where K1 is the equilibrium constant at absolute temperature T1, K2 is the equilibrium temperature at absolute temperature T2, R is the universal gas constant and ΔHr is the heat of reaction.
This equation illustrates that as the temperature increases the value of the equilibrium constant for an exothermic reaction decreases and hence the equilibrium position of the reaction moves towards the left. It will therefore be understood that in order to achieve a high conversion of the reactants to the products, the temperature of the reactor must be reduced sufficiently so that the equilibrium constant favours a higher concentration of the products than reactants.
For the particular equilibrium reaction of sulphur dioxide oxidation to sulphur trioxide, the equilibrium constant temperature dependence is often depicted as a chart showing the amount of sulphur dioxide converted to sulphur trioxide versus temperature. An example of this chart is illustrated in FIG. 1. Generally it is known that higher temperatures lead to higher kinetic reaction rates but since at higher temperatures the equilibrium constant favours higher concentrations of reactants, the amount of conversion to the desired products that can be achieved is limited. In the oxidation of sulphur dioxide to sulphur trioxide, the conversion rate is defined as the percentage of sulphur dioxide oxidised to the desired product. Thus as the reaction proceeds and the temperature rises, it is necessary to cool the reactants so that the equilibrium constant increases and the conversion of the sulphur dioxide is maximised.
In the conventional industrial process, simple fixed beds of catalyst are used. These beds will operate adiabatically with the temperature rising rapidly as the reactants flow across the catalyst in the bed. The result is that each bed can only perform a limited amount of oxidation before the equilibrium limit is reached. Once this point is reached, the gas has to be recovered from the adiabatic bed and cooled to move away from the equilibrium point. The cooled gas is then fed to a new fixed adiabatic bed such that further oxidation can occur. FIG. 2 illustrates a typical temperature profile for a reaction including this intermediate cooling
Whilst the problem associated with equilibrium limited reaction have been discussed with reference to the oxidation of sulphur dioxide, it will be understood that the issues applies equally to any other equilibrium limited reactions such as those for the reaction of ammonia and methanol.
A further problem associated with the oxidation of sulphur dioxide is that any unreacted sulphur dioxide remaining at the end of the process represents an environmental issue that needs to be removed from the exhaust gas before this can be vented to the atmosphere. It is therefore desirable to ensure that conversion is as high as possible to minimise sulphur dioxide emissions.
The conversion of sulphur dioxide to sulphur trioxide may be achieved by passing the sulphur dioxide through a series of adiabatic beds until typically 90% to 95% of it has been converted to sulphur trioxide. Then, in order to shift the gas composition further away from the equilibrium position, the gas is cooled and scrubbed with dilute sulphuric acid. This scrubbing step absorbs the product sulphur trioxide. The resulting product lean gas stream can then be reheated and fed to one or more further reaction beds where further reaction takes place to achieve typically more than 99.7% conversion of the sulphur dioxide. This is considered to be the minimal acceptable level of conversion that allows the exhaust gas to be vented to the atmosphere without further treatment. However, it will be understood that it is necessary to cool the gas stream before it is passed to the absorber. This need for cooling, the absorber itself and the post absorption reheating adds significantly to the capital and operation costs of the process.
FIG. 3 is a schematic representation of a reactor system for this arrangement including an intermediate absorption located before the final bed. In the example illustrated, the gas fed to the first adiabatic bed 2 in line 1 will be a mixture of sulphur dioxide, oxygen and nitrogen. This is fed to the bed at a temperature of about 690K. As the gases pass over the bed, reaction occurs and about 60% to about 70% of the sulphur dioxide is oxidised. A stream of unreacted gases and the sulphur trioxide formed is removed in line 3. This stream will have been heated to a temperature of about 870K. This is then cooled in heat exchanger 4 with the heat being recovered in line 5. The gases are cooled to about 700K before being passed in line 6 to the second catalyst bed 7 where further oxidation occurs. The gas stream recovered in line 8 will contain about 90% sulphur dioxide and will have been heated to about 750K. This is then cooled in heat exchanger 9 with the heat being recovered in line 10. The gas is passed to the third catalyst bed 12 in line 11 where further reaction occurs. The gas stream recovered in line 13 will include about 95% sulphur dioxide and will be at a temperature of about 720K. This is then cooled in heat exchanger 14 before being passed to intermediate absorber 15 in which the product is recovered by being scrubbed with sulphuric acid. The unreacted sulphur dioxide is passed in line 16 to heat exchanger 17 where it is heated to about 690K before being passed to the fourth catalyst bed 19 in line 18. Further reaction is carried out in this bed and the product stream is removed in line 20 at a temperature of about 700K. About 99.9% of the sulphur dioxide will have been converted. The four reaction beds 2, 7, 12 and 19 may be located in the same reactor shell 21. In this arrangement, impervious plates 22 are located between the catalyst beds 2, 7 12 and 19 are located between the beds.
The cost implications of this approach are prohibitive where only small volumes of sulphur dioxide are to be processed. In these cases, the adopted process is to accept a lower level of sulphur dioxide conversion and to omit the intermediate absorption stage. In this approach, after the removal of the product sulphur trioxide, any remaining sulphur dioxide is removed via an end of pipe treatment system. Whilst this process does not have the high costs associated with the absorption system, the requirement to provide and operate the end of pipe treatment system does add to the costs of the process.
Whichever system is used, there is always a post reactor absorption stage in which the sulphur trioxide is absorbed into sulphuric acid. The systems which include an absorption step before the final catalyst bed are known as a 'double contact acid plant' while those with only the end of pipe treatment system are known as a 'single contact acid plant'.
Similar processing problems arise with other equilibrium reactions.
A still further problem associated with equilibrium limited reactions is that associated with the optimum reaction temperature. Adiabatic multistage reactors with intermediate cooling are used particularly where the reaction proceeds selectively to give a single product but is limited by the equilibrium conditions. As discussed above, intermediate cooling is used to displace the gas temperature in the direction of higher equilibrium conversion. In exothermic reactions, such as the production of ammonia, sulphur trioxide and methanol, the equilibrium conversion to the target product decreases with increasing temperature. This is illustrated in FIG. 4.2A in Ullmann's Encyclopedia of Industrial Chemistry, Vol B4, 1992.
For a given conversion, at low temperatures the catalyst activity is reduced and the reaction will proceed slowly. As the temperature increases, the catalytic activity increases and the reaction rate also increases. However, as the temperature approaches the equilibrium point, the reaction rate will gradually decrease until the forward reaction matches the reverse reaction and the net reaction rate reduces to zero.
A temperature can therefore be found at which the reaction rate, with respect to the product, becomes a maximum. This temperature will be below the equilibrium temperature but will not be so low that the reaction becomes too slow for the reaction to operate kinetically. These points can be plotted to form a maximum reaction rate curve which is known as the locus of optimal reaction rate or Maximum Rate Locus (MRL). This is illustrated in FIG. 4.2B in Ullmann's Encyclopedia of Industrial Chemistry, Vol B4, 1992.
In the case of adiabatic reaction control the temperature increases linearly with the achieved conversion Δx according to the equation:
      Δ      T    =         -               Δ                   h       g                      l      G                                 ·             C       o                      ·             C               p                G                          ·    Δ         x   where each adiabatic reaction pathway of an exothermic reaction lies on a straight line of gradient ΔT/Δx as illustrated in FIG. 4.2A in Ullmann's Encyclopedia of Industrial Chemistry, Vol B4, 1992. A practical reaction pathway for a multistage adiabatic reaction can thus be derived from FIG. 4.2 in Ullmann's Encyclopedia of Industrial Chemistry, Vol B4, 1992 by joining straight-line sections for the adiabatic reaction to vertical lines for the temperature reduction due to indirect intermediate cooling as illustrated in FIG. 4.2C in Ullmann's Encyclopedia of Industrial Chemistry, Vol B4, 1992.
The kinetic optimum reaction pathway with the smallest required catalyst volume results when the trajectory follows, in a large number of small steps, the line of maximum reaction rate. In practice, the apparatus and equipment expenditure involved in using a large number of stages must be balanced against the savings in catalyst.
Conventional multistage reactors for this class of reaction often are limited to around three to five stages as otherwise the capital cost of the plant becomes excessive. However, it can be seen that in this case even if the capital cost is kept low a lot of the catalyst bed is operating at temperatures which are far from the optimum temperature and in the case of lower operating temperatures, the catalyst is not being fully utilised in its ability to perform the reaction. In this case, a much larger volume of catalyst is necessary which makes the cost of the catalyst higher and the size of the reactor larger.
Similar issues apply where the equilibrium reaction is an endothermic reaction.

Process and reactor comprising a plurality of catalyst receptacles

Johnson Matthey Davy Technologies Limited


A load detecting device includes a sensor element including a function for generating and detecting a vibration within a single element, the sensor element converting a load or an acceleration into a detection signal, a driving portion for outputting a driving signal for vibrating the sensor element, a vibration detecting portion for extracting the detection signal from the sensor element and for detecting a vibration characteristic value of the sensor element, a wiring for electrically connecting the sensor element, the driving portion and the vibration detecting portion to one another, and for transmitting a superimposed signal constituted by superposition of the driving signal from the driving portion and the detection signal from the sensor element, and a calculating portion for calculating one of or both of a load and an acceleration applied to the sensor element based on the vibration characteristic value from the vibration detecting portion.

A known load detecting device detects, using a piezoelectric element, not only a presence of a human body but also abnormality in a human body by extracting a human body-specific vibration component caused by heartbeat, breathing, and the like. For example, JP2000-230853A discloses a load detecting device including a vibration detecting means, a vibration characteristics calculating means, and a load calculating means. The vibration detecting means is arranged on a supporting member for supporting a human body and including a vibration generating portion and a vibration detecting portion provided adjacent to each other. The vibration characteristics calculating means calculates vibration characteristics through propagation of vibration generated by the vibration generating portion on the basis of an output signal from the vibration detecting portion. The load calculating means calculates a load applied to the vibration detecting means based on an output signal from the vibration characteristic calculating means. The vibration generating portion and the vibration detecting portion are both constituted by piezoelectric element. The load detecting device can be installed in a small space with the least trouble accordingly.
According to the load detecting device disclosed, however, since vibration is generated by one piezoelectric element and then the vibration is detected by other piezoelectric element, a piezoelectric member for generating vibration and a piezoelectric member for detecting the vibration are separately required. Thus, in order to measure distribution of load applied to a face of the supporting member and the like, a great number of pair of piezoelectric members for generating and detecting the vibration are necessary, which leads to complication of a structure and increase of a cost of the device.
Thus, a need exists for a load detecting device whose structure remains simple at a time of detection of distribution of load, and cost can be decreased.


Golf bag having elongated tubular body and shoulder strap assembly comprising first and second straps, each having first and second ends; and bridge member having first and second ends and being disposed undetachably between second end of first strap and second end of second strap; the elongated tubular body configured to be detachably adjoined to first end of first strap, first end of second strap, second end of first strap, and second end of second strap. Strap may have a first section, second section and third section that are configured to be adjacent the wearer's front, shoulder, and back, respectively; third section has curve with upper portion extending vertically with respect to wearer and lower portion extending horizontally with respect to wearer. A concave radius rcc can extend from strap first end to approximate the second end; wherein rcc>a convex radius rcv at the strap second end.

Both professional and recreational golfers use their golf bags for many different purposes today. The bags are normally designed to carry clubs and balls, and accessories such as head covers, towels, hats, umbrellas, and golf tees. Many golf courses require that golfers walk the entire course and carry their own bags. Thus, the golfer is constantly placing the bag over his/her shoulders, removing the bag from their shoulders, and placing the bag down or standing-up the bag using a support leg mechanism on the bag. The golfer is also constantly removing and placing different clubs in the bag depending upon the shot being made. Thus, the golf bag needs to be durable, relatively lightweight, and comfortable to carry.
Many golf bags have a two strap system so the golfer can bear the weight of the bag on both shoulders. The first strap fits over a person's first shoulder and the second strap fits over the second shoulder. These dual straps tend to help improve the weight distribution of the bag and less weight stress is placed on each shoulder. The person carrying the bag tends to have better balance while walking with the bag because of this improved weight distribution.
However, two strap systems can have some drawbacks. For example, the golfer may easily place the first strap over the first shoulder, but then have difficulty finding and swinging the second strap over the second shoulder. The golfer may have to twist their back and arms at odd angles in order to swing the second shoulder strap over their second shoulder. This turning and twisting can lead to back and arm injuries. Additionally, once the two-strap system is mounted about the golfer's shoulders, a golfer can have difficulty keeping the bag distributed across the golfer's back sufficiently to maintain an even gate while progressing along the terrain of the course.
Thus, golf bag manufacturers continue to develop improved dual shoulder strap assemblies which better facilitate both mounting of the straps about the golfer's shoulders as well as achieving and maintaining excellent distribution of the bag's weight across the golfer's back on the course. Such improved golf bags, if meanwhile durable, possessing high mechanical strength, and producible cost effectively within existing golf bag manufacturing processes, would be particularly useful and desirable. The current golf bag of the invention addresses and solves these needs.

Golf bag incorporating dual shoulder strap assembly


A stackable ball grid array (BGA) or fine ball grid array (FBGA) semiconductor package particularly suitable for board-on-chip or chip-on-board applications in which a low profile BGA or FBGA semiconductor package is needed. The stackable ball grid array (BGA) or fine ball grid array (FBGA) provides a semiconductor package that is capable of being burned in and tested in a more efficient and cost effective manner than prior known BGA or FBGA semiconductor packages. A high density, low profile memory module incorporating a plurality of the disclosed BGA or FBGA semiconductor packages in a stacked arrangement is further disclosed.

1. Field of the Invention
The present invention generally relates to board-on-chip and chip-on-board ball grid array, including fine ball grid array, semiconductor chip packages. The present invention more particularly relates to constructing ball grid array semiconductor chip packages that are particularly suitable for being burned-in and tested in a more efficient and cost-effective manner. The subject invention further provides stackable ball grid array semiconductor chip packages which may be used to form highly dense, low-profile microelectronic components in which the semiconductor chip, or device, is better protected.
2. State of the Art
Ball grid array (BGA), including fine ball grid array (FBGA), semiconductor device packages are well known in the art. For convenience, a representative prior art BGA package is shown in drawing FIGS. 1 through 3. BGA chip packages, such as exemplary chip package 10, often comprise a substrate 12, such as a printed circuit board, having an elongated aperture 14 extending through the middle thereof. A semiconductor die or device 16, such as a dynamic random access memory (DRAM) device for example, is mounted on the opposite or bottom side of the substrate which is not viewable in drawing FIG. 1. Semiconductor die or device 16 most often will have a plurality of bond pads 20 in single column or multiple columns on an active surface 18 of semiconductor die 16. The active surface 18 of semiconductor die 16 is shown facing upward and can be viewed through aperture 14 in drawing FIG. 1. Substrate 12 is provided with an upwardly facing top surface 22, as shown in drawing FIG. 1, having a plurality of contact or bond pads 24 located along the periphery of aperture 14. Circuit traces 26 located on or within substrate 12 serve to electrically connect bond pads 20 to respective electrically conductive, connective elements such as solder balls 28. The electrically conductive elements typically comprise solder balls in electrical communication with and attached to a contact pad (not shown in FIGS. 1–3), or can merely be a solder ball placed directly upon, or in electrical communication with, the termination point of a selected circuit trace 26. Gold-filled or other conductive metal-based solder balls are frequently used. Alternatively, conductive balls made of a conductive-filled epoxy material having specifically preselected conductive qualities are also frequently used. The conductive elements or balls are arranged in a grid array pattern wherein the conductive elements or solder balls 28 are of a preselected size or sizes and are spaced from each other at one or more preselected distances, or pitches. Hence, the term "fine ball grid array" (FBGA) merely refers to a particular ball grid array pattern having what are considered to be relatively small conductive elements or solder balls 28 being spaced at very small distances from each other resulting in dimensionally small spacings or pitch. As generally used herein, the term "ball grid array" (BGA) encompasses fine ball grid arrays (FBGA) as well as ball grid arrays. Typical solder ball sizes can be approximately 0.6 mm or less and the solder balls may have a spacing or pitch of approximately 0.80 mm or less. However, the present invention is not limited with respect to a particular solder ball diameter or pitch.
Contact or bond pads 20 on active surface 18 of semiconductor die 16 are electrically and, to an extent mechanically, attached to respective contact pads 24 located on active surface 18 of substrate 12 by way of respective bond wires 30 by wire bonding methods known and practiced within the art.
Referring now to drawing FIGS. 2 and 3, which are cross-sectional views taken along line 2/3—2/3 as shown in drawing FIG. 1, bottom side or surface 32 of substrate 12 and nonactive side 36 of semiconductor die 16 are denoted. Semiconductor die or device 16 is attached to bottom side 32 of substrate 12 by any suitable adhesive 34. Illustrated in drawing FIG. 3 is an encapsulant 38 disposed over contact pads 24, bond wires 30, and bond pads 20 so as to protect and secure the somewhat fragile bond wires and bond sites from environmentally induced corrosion or other physical harm during immediately subsequent processing, storage, shipment, further processing, and ultimately during end use.
For quality control purposes, as well as manufacturing efficiency, it is standard practice to burn-in and electrically test semiconductor chip packages, such as representative prior art chip package 10, prior to installing the packages on the next-higher level of assembly, such as upon a dual in-line memory module (DIMM). Those chip packages that do not successfully undergo burn-in and testing are either reworked and retested or scrapped in accordance with economic feasibilities of the particular chip package being manufactured. In order to perform such pre-installation burn-in and testing, that is, intentionally subjecting the packages to elevated voltages and temperatures and then running preliminary, and perhaps diagnostic, tests on BGA chip packages such as BGA chip package 10, the chip packages must be mounted in specifically designed test tooling. A simplified illustration of representative test tooling 40 is shown in drawing FIG. 4. Generally, each BGA chip package 10 is placed in chip-receiving cell 44 of tray or holder 42. Chip package 10 usually has, but may not have, encapsulant 38 disposed thereon at the time of burn-in and testing. Upon chip package 10 being properly seated in tray 42, probe head 46 is moved toward chip package 10 in the direction of the arrow so as to engage each probe 48 with a corresponding conductive element such as solder ball 28. Upon BGA chip package 10 being burned-in and tested, probe head 46 is withdrawn from the chip package and the chip package is removed from test tray or holder 42 and forwarded on for further processing depending on the test results.
Because there are typically a large number of such solder balls to be contacted by a like number of probes for each chip package which must be arranged in a precise array or pattern in order to make electrical contact with the underlying solder balls, the test tooling is quite expensive, as well as time consuming, to construct. The time and expense factors of providing specific test tooling for each type of BGA chip having a wide variety of ball grid array patterns is compounded when the particular BGA chips to be burned-in and tested are of the fine ball grid array variety wherein the balls and spacing are quite small, thereby making the construction of the chip package test tooling even more time consuming and expensive. Furthermore, the specific test tooling to be devised must not only accommodate, burn-in, and test a single chip package, but must also be able to simultaneously accommodate, burn-in, and test a significant number of other chip packages, which may or may not have been segmented from a common substrate and are usually positioned and accompanied by respective cells of test tooling so that production quantities can be produced economically. Thus, it can be appreciated that the time and expense of constructing BGA chip package test tooling which, by necessity, has a multiplicity of probes specifically sized and arranged in patterns which must exactly correspond to the respective solder ball array being tested, are significant hindrances to quickly introducing BGA chip packages and, in particular, FBGA chip packages having new and different solder ball array patterns to the very competitive semiconductor chip marketplace. Furthermore, the test probes of the test tooling must be designed not to unduly damage the solder balls which will ultimately be used to electrically and mechanically connect the chip package to the next level of assembly by solder ball attachment methods used within the art.
U.S. Pat. No. 5,977,784, issued to Pai on Nov. 2, 1999, and related U.S. Pat. No. 5,831,444, issued to Pai on Nov. 3, 1998, are directed toward a method and apparatus for testing BGA chip packages wherein chip packages are placed within a self-centering test housing wherein contacts of the chip package are brought into contact with respective matching contact pads in order to burn-in and test the chip package. However, the testing apparatus of Pai must be provided with matching test contacts having the same array or pattern of the contact pads of the chip package to be tested in order to properly test the chip package. Thus, the substrate in which the test pads are located must be specifically manufactured to match the specific grid array of the chip package to be tested, giving rise to previously discussed unwanted new product lead times and expenses.
U.S. Pat. No. 6,018,249 issued to Akram et al. on Jan. 25, 2000, and assigned to the assignee of the present invention, provides a further example of a testing system for the testing of chip packages having external contacts or bumps arranged in a BGA or FBGA pattern. Notwithstanding the desirable features of the Akram et al. patent, the disclosed testing system includes matching contacts being provided and suitably positioned for respectively connecting with a correspondingly positioned external contact or bump on the chip package to be tested.
U.S. Pat. No. 5,677,566 issued to King et al. on Oct. 14, 1997, and assigned to the assignee of the present invention, is directed toward overcoming a problem in the industry wherein bare chips are continuously made increasingly smaller yet the chip-molded, plastic resin encapsulated, package-to-external circuit electrical connection typically remains at a previous, industry-set size and configuration when chips were larger. The semiconductor chip package taught by the King et al. U.S. Pat. No. 5,677,566 patent is provided with a lead frame having leads that generally originate near the center of the package and extend generally laterally outwardly over the chip toward and, if desired, beyond the periphery of the encapsulating material which generally defines the chip package. The innermost region of each conductive lead is wire bonded to a respective bond pad located on the active surface of the chip. The conductive leads near the periphery of the chip are exposed for accommodating a solder ball or other conductive element on the upper surface of the package, which is ultimately to be mounted on a printed circuit board in accordance with previous industry standards. The laterally protruding outer end portions of the individual conductive leads facilitate testing of the chip as the ends can be contacted with presently used testing equipment. After testing, the protruding ends can be trimmed flush with the exterior of the plastic resin package. Alternatively, the laterally protruding outer end portions of the conductive leads may be trimmed prior to encapsulating the entire chip package with plastic resin. Although suitable for many applications, providing the separate lead frame and fully encapsulating the chip package of King et al. may unnecessarily add to the complexity and cost of manufacturing chips to be used in other applications.
U.S. Pat. No. 5,731,709, issued to Pastore et al. on Mar. 24, 1998, discloses a ball grid array semiconductor device and apparatus for testing the device. In particular, Pastore et al. disclose a chip mounted on the top surface of a substrate which has a plurality of conductive castellations positioned around the periphery of the substrate serving as redundant electrical connections that are in communication with respective bond pads on the semiconductor chip. The conductive castellations, which are disclosed as being conductive vias that have been formed in the substrate which are subsequently trimmed to define the periphery of the substrate, thereby cutting the conductive vias in half, are engaged by specifically designed test apparatus to avoid directly contacting solder balls located on the top surface of the substrate. The test apparatus includes a test socket designed to accommodate the semiconductor device having contact members to make contact with the conductive castellations located about the periphery. The disclosed test apparatus appears to have been specifically designed to accommodate the disclosed semiconductor device. Thus, it would appear that added monetary costs would be incurred upon constructing and incorporating such test apparatus, or at least the disclosed test socket, into a production line.
In addition to the semiconductor packaging industry being driven to increase the number of solder balls or conductive contacts that is to be included within a BGA chip package of a given surface area, the industry is also being driven to reduce the overall height or profile of packaged semiconductor chips so that components and modules incorporating such chips can be made yet smaller and more compact. Thus, the industry is seeking ways in which BGA chip packages can be constructed so as to further reduce their individual height. Furthermore, the industry is seeking ways in which BGA chip packages may be stacked one upon another, which are, in turn, attached to a substrate or board to provide modules, such as dual in-line memory modules, of ever slimmer profiles.
An example of a lead chip design in a BGA package is shown in U.S. Pat. No. 5,668,405, issued to Yamashita on Sep. 16, 1997. The Yamashita patent discloses a semiconductor device that has a lead frame attached to the semiconductor chip. Through-holes are provided in a base film that allows solder bumps to connect via the lead frame to the semiconductor device. The Yamashita patent requires several steps of attaching the semiconductor device to the lead frame, then providing sealing resin, and then adding a base film and forming through-holes in the base film. A cover resin is added before solder bumps are added in the through-holes to connect to the lead frame. Thus, the resulting structure lacks the ability to stack devices one on top of another and further requires special test tooling be provided to match the particular grid pattern of the solder bumps.
U.S. Pat. No. 5,677,566, issued to King et al. on Oct. 14, 1997, referenced earlier herein, discloses a semiconductor chip package that includes discrete conductive leads with electrical contact bond pads on a semiconductor chip. The lead assembly is encapsulated with a typical encapsulating material and the solder balls or conductive elements are formed to protrude through the encapsulating material to contact the conductive leads and make contact with an external circuit. Although the semiconductor chip has the leads wire bonded to bond pads located in the center of the die, thereby allowing the conductive leads to be more readily protected upon being encapsulated by the encapsulating material, the chip package construction of the King et al. patent lacks the ability to be stacked one upon another.
With respect to stacking semiconductor chip packages, there are various methods of stacking semiconductor devices in three-dimensional integrated circuit packages known within the art. One such design is disclosed in U.S. Pat. No. 5,625,221, issued to Kim et al. on Apr. 29, 1997. The Kim et al. patent discloses a semiconductor package assembly that has recessed edge portions which extend along at least one edge portion of the assembly. An upper surface lead is exposed therefrom and a top recess portion is disposed on a top surface of the assembly. A bottom recess portion is disposed on the bottom surface of the assembly, such that when the assembly is used in fabricating a stacked integrated circuit module, the bottom recess portion accommodates leads belonging to an upper semiconductor assembly to provide electrical interconnection therebetween. Unfortunately, the assembly requires long lead wires from the semiconductor chip to the outer edges of the assembly. These lead wires add harmful inductance and unnecessary signal delay and can form a weak link in the electrical interconnection between the semiconductor chip and the outer edges. Further, the device profile is a sum of the height of the semiconductor chip, the printed circuit board to which it is bonded, the conductive elements, such as the solder balls, and the encapsulant that must cover the chip and any wire bonds used to connect the chip to the printed circuit board. So, reducing the overall profile is difficult because of the geometries required in having the lead pads on the semiconductor chip along the outer periphery with extended lead wires reaching from the chip to the outer edges of the assembly.
It can be appreciated that one of the favorable attributes of BGA chip packages is that the total height or overall thickness of the chip package is quite thin compared to other chip packages. Thus, BGA chip packages lend themselves to be especially suitable for incorporation within memory modules such as SDRAM modules and, in particular, dual in-line memory modules (DIMM).
Accordingly, what is needed within the art is a ball grid array chip package that can be easily burned-in and tested by existing test tooling. Another need within the art is for low-profile ball grid array chip packages that can be stacked so as to have a minimum amount of stack height to allow the production of low-profile dual in-line memory modules, for example. Such low-profile stackable packages would ideally have a lower profile than otherwise provided in the prior art and would ideally be producible with as few production steps as is feasible, yet provide adequate protection of the semiconductor chip during shipping and handling.

Method for ball grid array chip packages having improved testing and stacking characteristics


A polymer-modified asphalt composition containing (a) about 80 to 99.7 weight percent of a polymer-asphalt reaction product prepared by reacting (i) about 100 parts by weight of an asphalt having an initial viscosity at 60.degree. C. of from 100 to 20,000 poise, with (ii) about 0.5 to 11 parts by weight a glycidyl-containing ethylene copolymer containing about 0.1 to about 20 weight percent glycidyl moieties and having a weight-average molecular weight of from about 10,000 to about 1,000,000; and (b) about 0.3 to 20 weight percent of a styrene/conjugated-diene block copolymer having a weight-average molecular weight of from about 100,000 to about 1,000,000.

1. Field of the Invention
This invention relates to polymer-modified asphalt compositions. More particularly, this inventions relates to polymer-modified asphalt compositions prepared from asphalt, a glycidyl-containing ethylene copolymer and a block copolymer derived from styrene and a conjugated-diene.
2. Description of the Related Art
It is well known that polymers can be used to modify the rheological properties of asphalt. A wide variety of polymers have been used for this purpose and numerous polymer-modified asphalt compositions are known in the art.
For example, polymer-modified asphalt compositions prepared using styrene/conjugated-diene block copolymers are described in "Modification of Asphalt by Block Polymers of Butadiene and Styrene" by G. Kraus, Rubber Chemistry and Technology, Vol. 55, No. 5, November-December 1982. Polymer-modified asphalts are also discussed in "Asphalt and Polymer Modified Asphalt Properties Related to the Performance of Asphalt Concrete Mixes" by J. L. Goodrich, Proc. of the Association of Asphalt Paving Technologists, Vol. 52, pp. 116-160 (1988).
Additionally, U.S. Pat. No. 4,217,259, issued Aug. 12, 1980 to C. R. Bresson, discloses an asphaltic concrete composition comprising an asphalt, a mineral aggregate, and a radial teleblock diene/monovinyl aromatic copolymer having a weight ratio of diene to monovinyl aromatic monomer of at least about 75/25 to about 90/10 and a weight average molecular weight of from about 150,000 to about 300,000. The asphaltic concrete compositions disclosed in this patent are taught to exhibit excellent flexural fatigue test characteristics.
Similarly, U.S. Pat. No. 4,172,061, issued Oct. 23, 1979 to C. R. Bresson, discloses an asphaltic concrete composition comprising an asphalt, a mineral aggregate, and composition using a sufficient amount p a hydrogenated radial teleblock diene/monovinyl aromatic copolymer having a weight ratio of diene to monovinyl aromatic monomer of about 70/30 and a weight average molecular weight of from about 70,000 to about 150,000.
U.S. Pat. No. 4,585,816, issued Apr. 29, 1986 to J. F. Vitkuske et al., discloses a method of preparing a mixture of asphalt and a block copolymer of AB(BA).sub.n configuration, wherein n is an integer from 1 to 10, block A is a vinyl aromatic and block B is a diene.
U.S. Pat. No. 4,145,322, issued Mar. 30, 1979 to P. Maldonado et al., discloses a process for preparing a bitumen-polymer composition comprising 80 to 98% by weight of a bitumen having a penetration value between 30 and 220, 2 to 20% by weight of a block copolymer of styrene and a conjugated-diene having a molecular weight between 30,000 and 300,000, and 0.1 to 3% by weight of sulfur. The bitumen-polymer compositions of this patent are taught to have excellent mechanical properties even at low temperatures.
U.S. Pat. No. 3,440,195, issued Apr. 22, 1969 to G. W. Norcross, discloses a thermoplastic sealing composition comprising a product obtained by heating at a temperature between about 200.degree. F. (93.degree. C.) and about 400.degree. F. (204.degree. C.) for at least 6 hours a mixture of (1) from 3.0 to 5.5 parts by weight of an asphalt and (2) a block copolymer comprising from 12 to 20 percent by weight of a polystyrene homopolymer block and the remainder a block of a copolymer of styrene and butadiene, the total weight of styrene in the block copolymer being less than 30 percent.
Styrene/conjugated-diene block copolymers have also been used in combination with other types of polymers to prepare polymer-modified asphalt compositions. For example, U.S. Pat. No. 3,978,014, issued Aug. 31, 1976 to E. J. van Beem et al., discloses a bituminous composition comprising 75 to 92 weight percent of a bituminous component, 4 to 15 weight percent of a block copolymer of monoalkenyl aromatics and conjugated alkadienes, and 4 to 15 weight percent of a thermoplastic polymer having a molecular weight higher than 10,000, a solubility parameter between 7.8 and 8.8 and a crystallinity of less than 60 percent at 25.degree. C. The bituminous compositions disclosed in this patent are taught to have improved properties with regard to storage stability, penetration, softening point, breaking point and adhesion.
Similarly, U.S. Pat. No. 4,282,127, issued Aug. 4, 1981 to H. F. M. Desgouilles, discloses a bitumen-based composition containing a ternary mixture of 52 to 78 weight percent bitumen, 20 to 40 weight percent polyolefin, and 2 to 8 weight percent of a butadiene-styrene copolymer. The bitumen-based compositions disclosed in this patent are taught to be useful for sealing purposes.
More recently, epoxide-containing ethylene copolymers, such as glycidyl-containing ethylene copolymers, have been used to prepared polymer-modified asphalts. For example, PCT International Application WO 91/09907, published Jul. 11, 1991, discloses a thermoplastic polymer-linked-asphalt composition prepared by reacting asphalt with an epoxide-containing reactant polymer, preferably a glycidyl-containing ethylene copolymer. The polymer-linked-asphalt product disclosed in this application is taught to be particularly useful in road paving and roofing applications. This patent application additionally teaches on page 18, lines 11-30 that certain non-reactive diluent polymers may be added to the asphalt compositions disclosed therein.
Although various polymer-modified asphalt compositions are known in the art, there still exists a need in the asphalt industry for improved polymer-modified asphalt compositions. In part, this is due to the fact that new asphalt performance criteria or specifications are continually being developed by various state and federal agencies in an effort to increase the effective life of paved roads and other asphalt products under diverse climatic conditions. Not all existing polymer-modified asphalt compositions are able to meet these new, more stringent specifications. Accordingly, a need exists for improved polymer-modified asphalt compositions and methods for preparing such compositions.
It has now been discovered that polymer-modified asphalt compositions having excellent performance properties can be prepared using the novel combination of a glycidyl-containing ethylene copolymer and a styrene/conjugated-diene block copolymer. Moreover, this unique combination of copolymers has been found to be especially useful for adjusting the rheological properties of an asphalt to meet certain asphalt specification requirements.

Polymer-modified asphalt composition and process for the preparation thereof

Chevron Research and Technology Company, a division of Chevron U.S.A. Inc.


The present invention is a laser (12) having a resonator (28) between an output coupling mirror (20) and a high-reflection mirror (26). A photoelastic plate (38) is incorporated in a photoelastic cell (24), or a photoelastic mirror (36) used in place of the high-reflection mirror (26). The photoelastic plate (38) is placed in the resonator (28) and introduces an artificial anisotropy to the laser (12). The photoelastic plate (38) has privileged directions (34), which are aligned with the axes of the artificial anisotropy. A magnetic field (32) is applied transversely to the resonator (28), in alignment with one of the privileged directions (34), to produce two orthogonal linearly polarized frequencies in an output beam (30) with the Zeeman effect.

The use of interferometry to measure changes in lengths, distances, and optical paths is well known in industry. Collectively such practice can be termed interferometric displacement measurement. In performing such measurement both homodyne and heterodyne techniques may be used, with the latter having come to be overwhelmingly preferred today. Of present interest are heterodyne techniques using two optical frequencies produced with a single laser device.
In general, in a single mode laser only one frequency of oscillation may be produced. In order to allow more than one frequency to oscillate simultaneously, new boundary conditions have to be introduced into the laser resonator so that more than one gain profile is formed. Each profile then provides gain for a respective polarization of light. The application of a magnetic field to at least part of the laser gain medium is one well known way to accomplish this, and inserting a birefringent material into a laser resonator to create a photoelastic effect producing different optical path lengths for different polarizations of light is another.
When a magnetic field is applied to a single longitudinal mode laser cavity, two oscillation frequencies may be produced which have orthogonal polarizations and are separated in frequency symmetrically with respect to the absolute frequency of the laser (its natural resonant frequency). This is commonly termed the Zeeman effect, and lasers using it are called Zeeman lasers. In a Zeeman laser the magnetic field may be applied along the same direction as the axis of the laser resonator (axially or longitudinally; to avoid confusion with longitudinal mode lasers, "axial" or "axially" are used hereinafter) or perpendicular to the axis of the laser resonator (transversely).
For axial type Zeeman lasers the frequency components produced have opposite circular polarizations and the maximum frequency split is typically a few megahertz, e.g., for He-Ne lasers approximately 4 MHz. [He-Ne lasers are used herein as examples. However it should be appreciated that the Zeeman effect may be obtained in other laser mediums and that the present invention may therefore also use such alternate mediums.] For transverse type Zeeman lasers the frequency components produced have opposite linear polarizations and the maximum frequency split is typically only a few kilohertz, e.g., for He-Ne lasers approximately 300 KHz.
The split dual frequencies obtainable with Zeeman lasers are particularly useful for interferometric displacement measurement using heterodyne techniques. A key benefit is that the Zeeman split is symmetric with respect to the absolute frequency, which can be determined very precisely for the particular laser medium used. It follows that the frequency for each frequency component can also be precisely determined. Zeeman lasers also achieve high signal-to-noise ratios. In interferometric displacement measurement these characteristics permit the interference fringes produced by the motion of a target object to be accurately measured, and the total displacement of the target may then be calculated by integrating the total number of such fringes through time. This method of displacement measuring is accurate and reliable, and has found wide use in industry.
In displacement interferometry the maximum obtainable frequency split imposes a limit on target speed during measurement (velocity=.lambda./2* Doppler frequency). For example, if a measurement target object is moved such that the Doppler effect causes a decrease in the frequency split, the measured frequency can decrease all the way to zero and the interferometer can cease to function. For axial He-Ne Zeeman lasers the maximum target movement rate, commonly called the "slew rate", is approximately 1.2 m/sec. For transverse He-Ne Zeeman lasers the maximum slew rate is considerably less (<0.1 m/sec). Today axial He-Ne Zeeman lasers are widely used in industry, but it is becoming increasingly desirable to perform displacement measurement using still higher slew rates.
One way to increase the frequency split produced by Zeeman type lasers is to apply a stronger magnetic field to the laser resonator. However, there are practical limits to this. As the magnetic field is made increasingly strong, a point is reached at which the gain medium starts to behave in a non-linear fashion, and second order Zeeman effects then cause unwanted modes and frequencies to appear. This confuses the detectors used in interferometer systems. Overly strong magnetic fields also push the gain of the media away from the absolute frequency, dramatically decreasing the laser power produced, until the point at which lasing stops entirely. Thus, there is an upper limit to the frequency split obtainable using the Zeeman effect.
The larger frequency split obtainable with axial type Zeeman lasers is the reason they are primarily used in industry today, despite the disadvantage that they produce circularly polarized light. This is a disadvantage in interferometry because linear polarized light is needed. To convert the output of axial type Zeeman lasers to linear polarizations, quarter-wave plates must be used. However, such conversion is never perfect, producing considerable noise that can severely complicate interferometric measurement. This also results in considerable loss in usable beam power. It should be particularly noted that transverse type Zeeman lasers do not suffer from this inherent disadvantage.
Other techniques than the Zeeman effect can also be used to create multiple frequencies for use in interferometry. One well known example is insertion of a birefringent material into a laser cavity to produce a birefringence. However, such other techniques generally also suffer a common shortcoming: they have a minimum obtainable frequency split of approximately 40 MHz, which is simply not practical for use in most current interferometry applications. Thus, current techniques are not able to produce split dual frequencies for interferometry in a range extending from roughly 4 MHz to 40 MHz.
Since the application of an axial magnetic field imposes a limit in the maximum frequency split obtainable, and the addition of birefringence imposes a limit in the minimum frequency split obtainable, it would seem logical that combining these techniques might produce a frequency split with no range limitations. However, there are physical laws adversely affecting such direct combination. When the Zeeman effect is produced by application of an axial magnetic field, the two frequencies produced are circularly polarized. However, since photoelastic birefringence materials can only produce different optical paths for linearly polarized light, this approach does not work. Alternately, when the Zeeman effect is produced by application of transverse magnetic field, the two frequencies produced are linearly polarized, but the natural anisotropy of the laser system produces a whole new set of problems.
Without a magnetic field, there are also two mutually perpendicular axes from the natural anisotropy of the laser itself, and it is the principal axis of this anisotropy which provides the least loss for an electromagnetic wave. Thus one component occurs in the polarization plane parallel to the principal axis, and saturation of the population drives the other component so that its polarization plane is perpendicular to the principal axis. Because the two components of a single longitudinal mode are strongly coupled with each other, the laser output falls within a locking frequency range, which provides linearly polarized light at a single frequency in some circumstances.
In a transverse Zeeman laser, the applied magnetic field defines the orientations for emitting linearly polarized light, namely a .pi.-component having a polarization plane parallel to the magnetic field and a .sigma.-component having a polarization plane perpendicular to the magnetic field. [The optical convention of referring to horizontal and vertical polarizations as p- and s-components is not used herein. Instead the physics convention of referring to .pi.- and .sigma.-components based upon the direction of the applied field is used, because it avoids confusion with light beam directions.] The polarizations of established light inside a laser are thus not only determined by the applied magnetic field, but also influenced by the natural anisotropy of the laser. The orientation of the linearly polarized laser beam can switch into some directions which are neither the direction of the applied magnetic field, which can easily be controlled, nor the orientations of the anisotropy of the laser, which cannot be controlled. Because it is desirable to use two mutually perpendicular linearly polarized components having a frequency split of several MHz for interferometric measurement, these characteristics of the transverse Zeeman laser prevent it from wide application in present precision measurement applications.
Accordingly, new techniques for achieving split dual frequencies having orthogonal linear polarizations for interferometric measurement are needed, particularly ones which produce frequency splits in the range from 4 MHz to 40 MHz.


A method of controlling a color image forming apparatus capable of preventing an image from being distorted at a boundary of a color image region due to mis-registration to improve printing quality. The method includes determining whether original image data is in a color image region, detecting boundary region information on a plurality of color channels when the original image data is in the color image region, selecting a channel to be extended using the detected boundary region information, and extending the selected channel.

1. Field of the Invention
The present general inventive concept generally relates to a method of controlling a color image forming apparatus, and more particularly, to a method of controlling a color image forming apparatus to compensate for distortion of an output image caused by a mis-registration during a printing of a color document.
2. Description of the Related Art
In general, an image forming apparatus converts a document created by a user who desires to print the document through an application program or an image photographed by the user using a digital camera into coded data to print the data on a recording paper so that the user can see the data.
An image forming apparatus capable of performing color printing includes toners of various colors, such as cyan (C), magenta (M), yellow (Y), and black (B). The color of printed data is realized by the combination of the toners of the various colors to be printed.
Different from a black-and-white printer, the color image forming apparatus paints one surface many times with different colors to print a color document. At this time, if in the process of painting one surface with various colors, the colors cannot be accurately painted on precise locations due to various reasons, such a phenomenon is referred to as mis-registration.
In particular, due to the mis-registration, dots of various colors scatter at a boundary of a color image so that remarkable image distortion may occur.
In this case, the dots of the various colors scatter at the boundary of the color image due to the mis-registration.
This is because positions of C, M, Y, and K dots on an image do not coincide with positions of the dots generated during the printing.
That is, the C, M, Y, and K dots deviate from the positions where the dots are to be marked due to a mechanical error, so that such a phenomenon occurs.
An image is distorted due to the mis-registration so that picture quality deteriorates.

Controlling color image formation by extending color channels based on boundary region information to compensate for mis-registration distortions


Aspects of the disclosure describe methods and systems for performing an antivirus scan using file level deduplication. In an exemplary aspect, prior to performing an antivirus scan on files stored on at least two storage devices, a deduplication module calculates a respective hash for each respective file stored on the storage devices. The deduplication module identifies a first file stored the storage devices and determines whether at least one other copy of the first file exists on the storage devices. In response to determining that another copy exists, the deduplication module stores the first file in a shared database, replaces all copies of the first file on the storage devices with a link to the first file in the shared database, and performs the antivirus scan on (1) the first file in the shared database and (2) the files stored on the storage devices.

Inside large organizations, there may be hundreds of thousands of computing devices including employee workstations, servers, mobile devices, tablet computers and the like. To keep the organization secure from data theft or corruption, the data on these devices must be scanned continuously for viruses and/or other malicious software. The regular scanning of the data on all of these devices can take a considerable time, however, and may overwhelm individual devices, storage disks and the networks they are attached to. An additional problem exists in that there may be duplicates of files stored in several locations on several computing devices—this may further increase scanning times significantly and also wastes processing power that can be used for another purpose.
There is a need, then, for a solution reduces the amount of time required for scanning all data across the organization, taking into account duplicate content while simultaneously minimizing anti-virus scanning procedures in an effective manner.

System and method for performing an antivirus scan using file level deduplication


Diamino polyacetate benzene compounds are used as a selective fluorescence probe, sensor, or binders for divalent metal ions. The compounds provide for uses as divalent metal ion sensors in diagnostic applications and binders for environmental and medical treatments.

With increased awareness for the detrimental impact of metals on human health and environment, it is highly desirable to develop more sensitive and selective probes for the detection of metal ions in biological and environmental samples. A variety of divalent metal ions are known to be involved in the structural, catalytic, and regulatory aspects of the biological system, and some such metal ions serve as prognostics of certain human diseases. For example, Cu2+, Zn2+, and Fe2+ have been found to be involved in aggregating β-amyloid peptides during the onset of the Alzheimer's disease. However, due to the lack of metal ion specific probes, the relative contribution of one type of metal ion versus the other in causing the disease is not clearly understood. The inability to differentiate among different types of divalent metal ions in biological samples has been one of the major impediments in the area of bio-analytical chemistry.
Although there has been some success in detection of biologically significant metal ions by developing fluorescence probes (e.g., fura-2 for Ca2+), most of the probes exhibit cross reactivity for other metal ions. This is not surprising since both physical and electronic properties of these metal ions are not too disparate, and they tend to exhibit comparable binding affinities with their cognate chelating agents. Consequently, not only synthetic (organic) probes but also enzymatic probes exhibit cross-reactivities among metal ions. Presently, quinoline-sulfonamide containing compounds and their derivatives are regarded to be as the "gold" standards for detecting low concentrations of Zn2+, albeit such compounds also exhibit selectivity for Cu2+. The origin of such selectivity appears to be encoded by facile changes in the coordination state of Zn2+ versus Cu2+. Unexpectedly, the invention herein describes a method for the synthesis and use of novel Zn2+ selective fluorescent compounds that exhibit a high specificity for Zn2+ with low reactivity to other divalent metal ions.


A dried adhesive coating is manufactured by steps of: a) providing a composition comprising a solution of a polymer, wherein at least 1 wt % of said polymer based on the molecular weight Mw are catechol groups, and wherein the concentration of said polymer in said composition is from 0.1 to 250 mg/ml, b) adjusting the pH of the composition to a value from about ó to about 7, either (i) before applying the composition to the surface to be coated or (ii) after applying the composition to the surface to be coated, c) applying the composition to the surface to be coated to obtain an adhesive coating on at least a part of the surface, and d) drying the coating.

In prior art it is well known that when the pH of a protein comprising DOPA residues is raised above about 5, auto oxidation of DOPA to dopaquinone is achieved. It is well known that this auto oxidation is faster with a higher pH.
In adhesive compositions intended for biological tissue it is not suitable to have very high or very low pH. From a perspective of sensitive tissues a pH value of about 5.5 to 7.5 is often suitable. It was always anticipated that such a low pH give too slow curing of the adhesive. Previous strategies to increase the speed of the adhesion have been to raise pH, as disclosed in WO 2003/051418, to lower the pH and use a concentrated solution as disclosed in WO 2004/005421, or add periodate ions as disclosed in WO 2003/080137.
WO 2003/051418 discloses method for attaching two surfaces or for coating a surface comprising the steps of a) providing a bioadhesive composition consisting of an aqueous solution of a bioadhesive polyphenolic protein derived from a byssus-forming mussel, which protein comprises 30-300 amino acids and consists essentially of tandemly linked peptide repeats comprising 3-15 amino acid residues, wherein at least 3% and preferably 6-30% of the amino acid residues of said protein are DOPA, wherein the concentration of said protein in said bioadhesive composition is within the range of 10-50 mg/ml; b) providing a strongly alkaline solution with a pH of 10 or more; c) (i) mixing said composition and said strongly alkaline solution and applying the mixture to at least one of two surfaces to be attached to each other or (ii) applying said composition and said strongly alkaline solution sequentially, without any specific order, to at least one of two surfaces to be attached to each other, thereby mixing the bioadhesive composition and the strongly alkaline solution; d) optionally joining said surfaces to each other; and e) leaving said surfaces for sufficiently long time for curing to occur. There is also disclosed a corresponding kit.
WO 2003/051418 further discloses mostly when using the polyphenolic proteins as adhesives the pH has had to be raised to neutral or slightly basic (commonly to from 5.5 to 7.5) in order to facilitate oxidation and curing of the protein. However it is added that curing is slow and results in poor adhesive strength. It is also taught that addition of oxidizers, fillers cross-linking agents often is necessary. The selected pH is from a perspective of adhesives to be used for tissues.
WO 2004/005421 discloses use of a composition as a sole component for attaching two surfaces to each other or for coating a surface, said composition consisting of an acidic aqueous solution of a bioadhesive polyphenolic protein derived from a byssus-forming mussel, which protein comprises 30-300 amino acids and that consists essentially of tandemly linked peptide repeats comprising 3-15 amino acid residues, wherein at least 3% and preferably 6-30% of the amino acid residues of said protein are DOPA, where the pH of said acidic solution is 4 or less, and wherein the concentration said protein is 10-250 mg/ml.
WO 2003/080137 discloses a method for attaching two surfaces or for coating a surface comprising the steps of a) providing a bioadhesive composition consisting of an aqueous solution of a bioadhesive polyphenolic protein, which protein comprises 30-300 amino acids and consists essentially of tandemly linked peptide repeats comprising 3-15 amino acid residues, wherein at least 3% and preferably 6-30% of the amino acid residues of said protein are DOPA; b) providing a preparation comprising periodate ions; c) mixing said bioadhesive composition and preparation comprising periodate ions so that the periodate ions constitutes at least 1.80 mmol/g of the final composition; d) (i) applying the mixture to at least one of two surfaces to be attached to each other or (ii) applying said composition and said preparation comprising periodate ions without any specific order, to at least one of two surfaces to be attached to each other, thereby mixing the bioadhesive composition and preparation comprising periodate ions; e) optionally joining said surfaces to each other; and f) leaving said surfaces for sufficiently long time for curing to occur.
Although the strategies used in the prior art give cured compositions there is room for improvement regarding the adhesive. For instance the strength of the adhesive may be improved.
Another problem in the prior art is how to provide an improved adhesive which can be dried, stored and used after a period of storage.
Yet another problem is how to provide a tissue friendly adhesive.


A method of forming an etch stop layer 40 above a fuse 16 in a fuse opening (or window) 92 using a specialized 2 stage etch process. The invention has two important features: First, the etch stop layer 40 is formed from a polysilicon layer (P2 or P4) that is used to fabricate semiconductor devices on a substrate. The etch stop layer 40 is preferably formed of polysilicon layer to is used to from a contact to the substrate 10 (P2) or to form part of a capacitor (P4). Second, a specialized two stage etch process is used where the second stage etches the etch stop layer 40 while simultaneously forming a passivation layer 114 over a metal pad 85. The method comprises: forming fuses 16 over said isolation regions 10 over the fuse area 15; forming a first dielectric layer 30 overlying the fuses 16; forming an etch stop layer 40 over the first dielectric layer 30; forming an insulating layer 43 over the etch stop layer; forming a fuse opening 92 in the insulating layer 43 by etching, in a first etch stage, thorough fuse photoresist openings 90A and stopping the first etch stage on the etch stop layer 40; and etching though the etch stop layer 40 in the fuse opening 92 in a second etch stage.

1. Field of the Invention
This invention relates generally to the fabrication of etch stops for openings through dielectric layers over fuses for semiconductor devices and more particularly to the uses of an etch stop layer over fuses and a specialized etch process that forms a fuse opening without etch an exposed metal pad.
2. Description of the Prior Art
Fuses can be used to rewire memory and logic circuits. For example, in dynamic or static memory chips, defective memory cells may be replaced by blowing fuses associated with the defective cells, and activating a spare row or column of cells. This circuit rewiring using fusible links allows considerable enhanced yields and reduces the production costs. Also, logic circuits may also be repaired or reconfigured by blowing fuses. For example, it is common to initially fabricate a generic logic chip having a large number of interconnected logic gates. Then, in a final processing step, the chip is customized to perform a desired logic function by disconnecting the unnecessary logic elements by blowing the fuses that connect them to the desired circuitry. Still other applications of laser-blown fuses are possible. There are two methods for blowing fuses: (a) using a laser and (b) passing a high current through the fuse. The portion of the fuse and thin insulating layer which is melted away or "blown" must not deposit or interfere with near-by devices. A laser is often used to break the fuse forming an electrical open by heating the fuse to a high temperature. It is conventional to have an opening through insulating layers over the fuse in the area where the fuse will be broken.
The inventor has found major problems the process of forming opening over fuses. As the number of metal layers and inter metal dielectric (IMD) layers increases, it is more difficult to accurately etch a fuse opening to a precise depth. This etch variability changes the thickness of dielectric layer overlying the fuse. The varying dielectric layer thickness over the fuse reduces the laser fuse cutting rate and yields. Moreover, the additional inter metal dielectric layers, the dielectric layer uniformity within wafer and wafer to wafer create difficulty in accurately etching fuse openings.
The importance of overcoming the various deficiencies noted above is evidenced by the extensive technological development directed to the subject, as documented by the relevant patent and technical literature. The closest and apparently more relevant technical developments in the patent literature can be gleaned by considering: U.S. Pat. No. 5,292,677 (Dennison) that teaches a reduced mask CMOS process for fabricating stacked capacitor multi-megabit dynamic random access memories utilizing single etch stop layer for contacts. An etch stop layer is deposited on a DRAM wafer after formation of the PMOS and NMOS transistors. U.S. Pat. No. 4,997,789 (Keller) shows an etch stop for a contact plug process. U.S. Pat. No. 5,256,597 (Gambino) shows an etch stop for an interconnect patterning. U.S. Pat. No. 5,536,678 (Peek) shows another etch stop configuration.
However, there still exists a need for an improved etch process with etch stops to form fuse windows through dielectric layers.

Etch recipe for embedded DRAM passivation with etch stopping layer scheme

Taiwan Semiconductor Manufacturing Company, Ltd.


A polycarbonate-based resin composition excelling in not only impact resistance but also other physical properties comprises 6 to 90% by weight of a polycarbonate/polyorganosiloxane copolymer, 10 to 60% by weight cf glass fibers and 0 to 84% by weight of a polycarbonate resin. The amount of the polyorganosiloxane contained in the resin components is in a range of 0.5 to 40% by weight.

1. Field of the Invention
The present invention relates to a polycarbonate-based resin composition and, more particularly, to a glass fiber-reinforced polycarbonate-based resin composition excelling specially in impact resistance and is suitable for use in various industrial materials.
Prior Art
Polycarbonate resins excel in mechanical strength, electrical characteristics, transparency, etc., and find various applications in the form of engineering plastics.
Additionally, there is known a glass fiber-reinforced polycarbonate resin in which glass fibers are incorporated into a polycarbonate resin to improve its rigidity and dimensional stability.
However, the addition of glass fibers tends to give rise to a drop of Izod impact strength due to brittle fracture. For that reason, compositions comprising such glass fiber-reinforced polycarbonate resins and further including an organo-polysiloxane have been proposed (see Japanese Patent Publication No. 35929/1984 and Japanese Patent Laid-Open (Kokai) Publication No. 501860/1982).
A problem with molded or otherwise shaped articles obtained from such compositions is, however, that they are poor in insulating properties.
With that problem in mind, compositions of glass fiber-reinforced polycarbonate resins containing a small amount of organopolysiloxane/polycarbonate copolymers have been proposed (see Japanese Patent Kokai Publication No. 160052/1980).
While such compositions are improved in terms of impact resistance to some extent, their impact resistance is still not enough to find use in fields for which especially high impact resistance is needed, for instance, chassis or electrically powered tool fields.


Disclosed are terpolymer adhesives comprising three different repeating domains: a catechol containing domain, a zwitterionic domain, and a crosslinking domain. In specific examples, the polymer can contain a 3,4-dihydroxy-L-phenylalanine (DOPA) segment which contains a catechol group, a poly(sulfobetaine methacrylate) (polySBMA), and poly(ethylene glycol) dimethacrylate (PEGDMA) for light crosslinking. Alternatively, a photocleavable nitrobenzyloxycarbonyl containing crosslinker can be used. The disclosed polymers can be used as biomedical adhesives, such as to prevent leakage from the sutured intestinal tissue.

Biomedical adhesive polymers are nonmetallic materials which possess the ability to join together two tissue surfaces by bonding. Tissues targeted by biomedical adhesives cover everything from hard tissues (bone, tooth, cartilage) to soft tissues (most other organs). The most extensively studied area of application of biomedical adhesives is the replacement of conventional wound closure methods such as sutures and staples (F. Scognamiglio, et al., J. Biomed. Mater. Res., Part B 2016, 104, 626-639; K. Park, J. Controlled Release 2014, 190, 3-8; W. D. Spotnitz. Am. Surg. 2012, 78, 1305-1321). In addition to wound closure, biomedical adhesives have also been applied as hemostatic agents, sealants, wound dressings, and drug delivery matrices (L. Serra, et al., Eur. J. Pharm. Biopharm. 2009, 71, 519-528; J. Xu, et al., Biomaterials 2015, 37, 395-404).
Conventional biomedical adhesives come in two major forms, the first being fully-synthetic adhesives including cyanoacrylate-based adhesives (e.g., Dermabond, Omnex, Histoacryl blue, Glubran 2, Surgiseal, Gluseal, Pattex, and Indermil) and poly(ethylene glycol) (PEG)-based adhesives. The second class of adhesives includes protein-based adhesives primarily containing fibrin (e.g., Tisseel, Crosseal, and Evicel), gelatin (e.g., GRF glue and Gluetiss), and albumin (e.g., BioGlue)(W. D. Spotnitz, AORN J. 2014, 100, 160-176; S. S. Kommu, et al., Rev. Urol. 2015, 17, 150-159; W. D. Spotnitz. ISRN Surg. 2014, 203943; S. P. Mandell, et al., Expert Opin. Biol. Ther. 2014, 14, 821-830; W. D. Spotnitz, et al., Clin. Appl. Thromb./Hemostasis 2010, 16, 497-514; W. D. Spotnitz, et al., Transfusion 2008, 48, 1502-1516; N. F. Pursifull, et al., Curr. Opin. Neurol. 2007, 17, 396-401). These current adhesives are widely applicable but suffer from a number of shortcomings. Cyanoacrylate adhesives, for example, are incompatible with internal soft tissue because of the stiffness of the resulting adhesive layer as well as the moderate amount of heat generated during the curing process. Protein-based adhesives which utilize rapid crosslinking action between serum and crosslinkers (stored separately in a dual-barreled syringe) offer certain advantages but suffer from poor temporal and spatial control during application. Additionally, the most common crosslinking agent, glutaraldehyde, may pose some safety concerns (T. Takigawa, et al., J. Occup. Health 2006, 48, 75-87). Therefore, the design of a biomedical adhesive to combat these shortcomings would be of high value to the surgical and greater medical community and there exists a strong need for new advanced functional materials in the field of biomedical adhesives, as well as in other fields. The compositions and methods disclosed herein address these.
Additionally, recent research has seen a trend of multifunctionality in biomedical adhesives with such functions as sensitivity toward external stimuli and drug delivery being combined with the traditional properties of a conventional polymer adhesive (B. T. Michal, et al., ACS Appl. Mater. Interfaces, 2016, 8, 11041-11049; M. A. C. Stuart, et al., Nat. Mater., 2010, 9, 101-113; L. Serra, et al., Eur. J. Pharm. Biopharm., 2009, 71, 519-528; T. Harper, et al., ACS Appl. Mater. Interfaces, 2017, 9, 1830-1839; Y. Jiao, et al., Colloids Surf., B, 2016, 140, 361-372). Stimulus-responsive adhesive polymers offer the ability to change their chemical structure upon receiving stimuli from the environment, often resulting in a significant change of bulk properties. Such stimuli include pH changes, light, changes in temperature, electricity, magnetic fields and mechanical forces (D. Kuckling, et al., in Polymer Science: A Comprehensive Reference, eds. K. Matyjaszewski and M. Möller, Elsevier, Amsterdam, 2012, vol. 8, pp. 377-413). Stimuli-responsive polymers are already used for a variety of applications including sensors, drug delivery, tissue engineering, and reconstructive polymer architectures. Recent advances in polymer synthesis and characterization has granted researchers the ability to precisely introduce functional groups within a macromolecular architecture, an advancement that functional polymers have leveraged to great effect. However, there are relatively few studies involving adhesive polymers containing multiple functionalities with the ability to respond to external stimuli, mainly because of the synthetic challenge still present in creating such polymers. What are thus needed are new stimuli-responsive multifunctional polymer adhesives and methods of making and using them. The compositions and methods disclosed herein also address these needs.

Zwitterionic crosslinked polymer-based adhesives

THE FLORIDA STATE UNIVERSITY RESEARCH FOUNDATION, INC.


Disclosed herein is a heat radiating substrate including: a heat radiating plate having a step formed so that one side and the other side thereof have thicknesses different from each other; a conductor pattern layer formed over the heat radiating plate and including a mounting pad on which a control device and a power device are mounted and a circuit pattern; and an insulating layer formed between the heat radiating plate and the conductor pattern layer.

1. Technical Field
The present invention relates to a heat radiating substrate and a method of manufacturing the same.
2. Description of the Related Art
Recently, in accordance with the development of an electronic industry, the demand for improvement in a function of an electronic component has rapidly increased. Further, in accordance with slimness and lightness of the electronic components, in connection with a circuit board on which the electronic components are mounted, a large number of electronic products should be integrated in a small area of the circuit board.
Meanwhile, high heat generating devices generating high heat, such as a power device, a light emitting diode (LED), and the like, are mounted on the circuit board. In the case in which the heat generated by the high heat generating devices are not rapidly radiated, a temperature of the circuit board is raised to cause an operation of the heat generating device to be disabled and cause a malfunction of the heat generating device. Therefore, research into a heat radiating substrate, which is a circuit board with improved heat radiation characteristics, has been conducted.
A heat radiating substrate according to the prior art has a structure in which both of a power device generating high heat and a control device vulnerable to heat are mounted on a heat radiating plate (U.S. Pat. No. 6,432,750). In addition, the heat radiating plate is made of a material having excellent heat conductivity in order to radiate the heat of the power device. In this case, since the power device and the control device are mounted on the same heat radiating plate, the heat generated from the power device may be conducted to the control device through the heat radiating plate. Therefore, the control device is affected by the heat generated from the power device, such that it may malfunction.

Heat radiating substrate and method of manufacturing the same


A computer-implemented method, carried out by one or more processors, for a modified asynchronous replication session. In an embodiment, the method comprises the steps of acquiring a lock on a volume configuration, where the lock prevents changes to the volume configuration between a first volume and a second volume at a remote site. Internal control block information is updated, where the update includes at least a volume serial number of the first volume matching a volume serial number of the second volume. Responsive to updating internal control block information, the acquired lock is released to allow changes to the volume configuration.

In the present day, High Availability (HA) solutions provide the ability to recover from storage failures at a production site, while Disaster Recovery (DR) solutions provide the ability to recover from regional disasters. Combining the two solutions, High Availability and Disaster Recovery, allow for a more comprehensive coverage of production data at the production site. However, there are instances where the combination of High Availability and Disaster Recovery may not provide desired coverage during certain failure modes. In one example of a failure mode, issues related to storage at the Disaster Recovery site may result in a loss of Disaster Recovery protection. In another example, after performing Disaster Recovery, data may not be protected by a High Availability solution.

High availability protection for asynchronous disaster recovery

International Business Machines Corporation