A process for enhancing the activity of a catalyst metal particulate for hydrogenation reactions comprising calcining the particulate in an oxidant-containing atmosphere to partially oxidize it thereby forming a porous layer of oxides thereon, treating with an solution capable of oxidizing the calcined metal particulate and comprising a compound of a hydrogenation catalyst metal to where said metal particulate has absorbed a volume of solution equal to at least about 10% of its calculated pore volume and activating it by treatment with a hydrogen-containing gas at elevated temperatures thereby forming a dispersed active metal catalyst. Preferably, the treated particulate is calcined a second time under the same conditions as the first before final activation with a hydrogen-containing gas. The metal particulate is preferably sized after each calcination and any agglomerates larger than 250 microns are comminuted to a desired size.

The production of higher hydrocarbon materials from synthesis gas, i.e. carbon monoxide and hydrogen, commonly known as the Fischer-Tropsch ("F-T") process, has been in commercial use for many years. Such processes rely on specialized catalysts. The original catalysts for the Fischer-Tropsch synthesis were nickel. Nickel is still the preferred catalyst for hydrogenation of fats and specialty chemicals. Over the years, other metals, particularly iron and cobalt, have become preferred in the Fischer-Tropsch synthesis of higher hydrocarbons whereas copper has been the catalyst of choice for alcohol synthesis. Cobalt is particularly preferred for Fischer-Tropsch synthesis due its high productivity and comparatively low methane selectivity. As the technology of these syntheses developed over the years, the catalysts have become more refined and have been augmented by other metals and/or metal oxides that function to promote their catalytic activity. Promoter metals or metal oxides include, without intended limitation, Ru, Os, Ir, Mo, W, Cu, Si, Cr, Ti, Mg, Mn, Zr, Hf, Al, Th and the like. It is generally recognized that the choice of a particular metal or alloy for fabricating a catalyst to be utilized in Fischer-Tropsch synthesis will depend in large measure on the desired product or products.
In 1924, M. Raney prepared a nickel hydrogenation catalyst by a process known today as the Raney Process. For purposes of simplicity, the term "Raney" will be utilized herein as a generic term to describe the process, alloys and catalysts obtained thereby. This specific synthesis, in essence, comprises forming at least a binary alloy of metals, at least one of which can be extracted, and extracting it thereby leaving a porous residue of the non-soluble metal or metals that possess catalytic activity. The residue, or non-extractable, catalyst metals are the art-recognized group of metals described above. The extractable metals, typically aluminum, are likewise an art-recognized group. Once alloys are formed of at least one member of each of these groups of metals, they are ground to a fine powder and treated with strong caustic, such as sodium hydroxide, to leach the extractable metal from the residue metal or metals.
There exist many variations of the basic preparation of Raney catalysts such as, for example, deposition of alloys onto a preformed support by flame spraying, (U.S. Pat. No. 4,089,812), formation of the alloy by surface diffusion of aluminum on a non-leachable metal substrate (U.S. Pat. No. 2,583,619), and forming pellets from the powdered alloys for use in fixed bed reactions vessels (U.S. Pat. No. 4,826,799, U.S. Pat. No. 4,895,994 and U.S. Pat. No. 5,536,694). These developments have made possible the use of shaped Raney catalysts in fixed bed reaction vessels.
Particularly suited for the production of hydrocarbons by Fischer-Tropsch synthesis from synthesis gas are Dispersed Active Metals ("DAM") which are primarily, i.e. at least about 50 wt. %, preferably at least 80 wt. %, composed of one or a mixture of metals such as described above and are, without further treatment, capable of catalyzing Fischer-Tropsch synthesis. DAM catalysts may be prepared by any of a number of art-recognized processes. An extensive review of process of forming DAM catalysts can be found in "Active Metals", Edited by Alois Furstner, published by VCH Verlagsgesellschaft mbH, D-69451 Weinheim (FRG) in 1996 and the references cited therein. Methodologies described therein include the Reike method, the use of ultrasound, reduction of metal salts, colloids, nanoscale cluster and powders. Other relevant references include, for example, the preparation of amorphous iron catalyst by high intensity sonolysis of iron pentacarbonyl, Suslick et al., Nature, Vol. 353, pp 414-416 (1991) and the formation of single domain cobalt clusters by reduction of a cobalt salt with hydrazine, Gibson et el., Science, Vol. 267, pp 1338-1340, (1998). Finally, intermetallic alloys, particularly those known for forming metal hydrides, such as LaCo5, can be formed into a fine powder by the application of hydrogen adsorption/desorption cycles. Such catalysts can also be prepared by thermal or chemical decomposition of metal formates or oxalates.
It will be appreciated that a means of producing DAM catalysts having enhanced activity for hydrogenation reactions would be of significant value. In particular, an important aspect of the value of a catalyst for the Fischer-Tropsch process, in addition to its activity, is its selectivity. This property, commonly referred to as "methane selectivity", is the ratio of the percent of feed material converted to desired higher hydrocarbons to that of short chain hydrocarbons produced, primarily methane. In accordance with the present invention, it has been found that DAM catalysts possessing enhanced activity and methane selectivity can be produced from particulate metals, such as Fischer-Tropsch cobalt catalysts, by a process that is both simple and economical.

ExxonMobil Research and Engineering Company


An antenna uses an at least substantially straight microstrip line as the feed for a linear array. A row of microstrip loops is located on a side of the feed line and at least substantially parallel to the feed line. Multiple iterations of this arrangement may be used to form a planar array antenna.

The vast majority of vehicles currently in use incorporate vehicle communication systems for receiving or transmitting signals. For example, vehicle audio systems provide information and entertainment to many motorists daily. These audio systems typically include an AM/FM radio receiver that receives radio frequency (RF) signals. These RF signals are then processed and rendered as audio output.
Vehicle video entertainment systems are gaining in popularity among motorists who want to provide expanded entertainment options to rear seat passengers, such as children. Rear seat passengers in vehicles equipped with video entertainment systems can watch movies or play video games to pass time during lengthy trips.
Some vehicle video entertainment systems incorporate tuners capable of receiving broadcast signals in the VHF and UHF frequency bands. Such systems allow passengers to watch broadcast television, further expanding their entertainment options. However, programming is limited to local broadcast stations. In addition, picture and sound quality is limited by the analog nature of the broadcast signals. Further, signal quality may be poor in some areas, such as remote locations.
Satellite-based broadcast systems, such as Direct Broadcast Satellite (DBS), provide subscribers with digital television programming. Because the signals used by DBS systems are digital, picture and sound quality is enhanced relative to traditional analog broadcasting systems. In addition, a DBS transmitter can provide coverage for a much larger geographic area than the terrestrial-based transmitters used by analog broadcasters. For example, it is possible to travel across a large portion of the United States without needing to change channels as different metropolitan areas are entered and exited.
Some conventional DBS receivers use a circularly polarized microstrip linear or planar array antenna to receive satellite signals. Circular polarization has long been used for communications, among other applications. Circular polarization is particularly well-suited for applications involving mobile receivers because the orientation of a circularly polarized signal does not change relative to the receiver as the receiver moves. Circularly polarized microstrip linear array antennas are preferably characterized by high efficiency, small beam walking, and good axial ratio at the satellite look angles.
Conventional microstrip linear array antennas include the rampart line linear array antenna and the loop line linear array antenna. Both of these types of microstrip linear array antennas suffer from large losses and extensive beam walking. Another conventional type of microstrip linear array antenna, known as the herringbone linear array antenna, does not provide a good axial ratio off its mechanical boresight.


Various semiconductor chip packages and methods of making the same are disclosed. In one aspect, a method of manufacturing is provided that includes coupling a solder bump to a side of a semiconductor chip and bringing the solder bump into contact with a conductor pad coupled to a substrate and positioned in an opening of a solder mask on the substrate. The conductor pad has a first lateral dimension and the opening has a second lateral dimension that is larger than the first lateral dimension. A metallurgical bond is established between the solder bump and the conductor pad.

1. Field of the Invention
This invention relates generally to semiconductor processing, and more particularly to methods and apparatus for electrically connecting a semiconductor chip to a package substrate.
2. Description of the Related Art
Many present day semiconductor chips are mounted to a package substrate that is, in-turn, mounted to another printed circuit board. A package substrate is typically larger in size than its companion chip. A package substrate serves several purposes. In one aspect, a package substrate provides a convenient interface between a typically small semiconductor chip and a normally much larger printed circuit board. In another aspect, a package substrate provides a mounting surface and conductive pathways for a variety of passive components, such as capacitors, that are useful for the operation of but cannot be easily incorporated into a semiconductor chip.
In order to serve as an interface between a semiconductor chip and a printed circuit board, a typical package substrate includes a collection of conductor lines that may be interspersed in several different layers of insulating material. A variety of schemes are used to link the substrate conductor lines to a printed circuit board. Pins, solder balls and land pads are examples of structures used to connect to a printed circuit board. Similarly, a variety of techniques are used to electrically connect a semiconductor chip to the conductor lines of a package substrate. Two such techniques are bond line connections and flip-chip solder bump connections.
In one conventional flip-chip solder bump design, a package substrate includes a mounting surface that is destined to receive a semiconductor chip. The mounting surface includes a collection of conductive bump pads and component pads. A solder mask is formed on the mounting surface and patterned lithographically with a series of openings that lead to the bump pads and the component pads. The openings leading to the bumps pads are patterned with a lateral dimension that is smaller than the lateral dimension of the bump pad. In one conventional design, the bump pads have a round footprint. In another conventional design, the bumps pads have a rectangular footprint. A solder stencil is next placed on the solder mask. The solder stencil has an array of openings that line up vertically with the collection of openings in the solder mask. Solder is pressed into the openings and the stencil is removed. To provide the solder structures present in the bump pad openings with an improved and consistent shape, a coining operation is performed. The coined solder structures are often referred to as a "pre-solders". Conventional pre-solders are typically composed of low temperature melting point solders, such as tin-lead eutectics.
To interface with the pre-solders of the package substrate, the semiconductor chip is provided with a group of solder bumps. Some conventional chip solder bumps are composed of high lead content lead-tin solder. To form the solder bumps in such cases, a high lead content lead-tin solder is deposited on conductive bump pads of the semiconductor chip. The semiconductor chip (usually at the wafer stage) is next heated to a high enough temperature to reflow the solder bumps. The wafer is subsequently diced into individual chips. A given individual chip is seated on a package substrate so that the solder bumps of the chip are brought into contact with the pre-solders of the package substrate and a reflow is performed to merge the solder bumps and pre-forms into conductive pillars. The metallurgical bonding between the high lead content tin-lead solder bumps and the pre-solders is not the result of the melting and wetting of both the low melting point eutectic pre-solders and the high melting point solder bumps. Rather, the reflow is performed at a little above the melting point of the eutectic pre-solders but well below the melting point of the high lead content solder bumps such that the metallurgical bonding is due to pre-solder liquification and wetting to the solid phase solder bumps. Thus, by using eutectic pre-solders, the substrate need not be subjected to potentially damaging high temperatures that would be necessary to melt the high lead content tin-lead bumps.
The foregoing conventional pre-solder design has been successfully used on a number of package designs. However, the materials, tools and processing time required to form an array of pre-solders do represent cost items that add to the overall cost of producing a packaged semiconductor chip.
The present invention is directed to overcoming or reducing the effects of one or more of the foregoing disadvantages.

Semiconductor chip bump connection apparatus and method


A semiconductor component comprises a semiconductor body that has its underside secured on a metallic substrate and is joined at its upper side to an auxiliary member composed of a material having great thermal conductivity and which serves as a heat buffer. This auxiliary member increases the loadability of the semiconductor component with respect to additional, thermal stressing pulses.

The invention is directed to a semiconductor component comprising a semiconductor body that has its underside secured on a metallic substrate.
For example, EP-A-0 242 626 discloses a semiconductor component of this type. One must thereby often proceed on the basis of a brief-duration thermal stressing that is present, for instance, given employment of such a component as a switch in a load circuit. Such a pulse-shaped stressing, however, can lie above the admissiblt continuous load without a destruction of the component occurring as a result thereof insofar as the thermal stressing pulses lead to a temperature of the semiconductor component that does not even briefly exceed a maximum value.

Semiconductor component and method for the manufacture thereof


An iPVD system uses a high density inductively coupled plasma (ICP) at high pressure of at least 50 mTorr to deposit uniform ultra-thin layer of a tantalum nitride material barrier material onto the sidewalls of high aspect ratio nano-size features on semiconductor substrates, preferably less than 2 nm thick with less than 4 nm in the field areas. The process includes depositing an ultra-thin TaN barrier layer having a high nitrogen concentration that produces high resistivity, preferably at least 1000 micro-ohm-cm. The ultra-thin TaN film is deposited by a low deposition rate process of less than 20 nm/minute, preferably 2-10 nm/min, to produce the high N/Ta ratio layer without nitriding the tantalum target. The layer provides a barrier to copper (Cu) diffusion and a high etch resistant etch-stop layer for subsequent deposition-etch processes.

In the metallization of high aspect ratio vias and trenches on semiconductor wafers, it is required that the barrier and seed layer have good sidewall coverage. Physical Vapor Deposition (PVD) processes have long been recognized as having certain advantages, namely their simplicity, their cleanliness, and other long known factors. However, most applications of PVD processes in semiconductor manufacture have encountered performance limitations, which have motivated the use of otherwise less desirable processes to overcome these limitations. For example, CVD processes are often resorted to for achieving high conformity and ALD processes are resorted to for achieving ultra-thin films.
Ionized PVD deposition have been preferred for barrier and seed layer metallization in advanced IC wafers in many applications. For example, IPVD has been used for applying tantalum nitride (TaN) barrier layers for copper (Cu). Ionized PVD provides good sidewall and bottom coverage in via and trench structures. However, as the geometries shrink and as the via dimensions go down below 0.15 micrometers, ionized deposition requirements become more critical. Therefore, it is highly desirable to have an ionized PVD process where bottom and sidewall coverage are well balanced and overhang is minimized.
Many prior art attempts to provide TaN barrier layers that effectively prevent oxidation of copper due to movement of oxygen from low-K dielectric substrates have resulted in the loss of conformality of the deposited film or nitridation of the tantalum target or other degradations in process performance.
Accordingly, there is a need to provide for the PVD of barrier layers of materials including TaN that overcome the problems of the prior art. Further, there remains a need to better control step coverage of the metal or the overhang that typically develops during the deposition step.

Barrier deposition using ionized physical vapor deposition (iPVD)


The present invention is concerned with a catalyst composition comprising titanium-, zirconium- and/or hafnium amidinate complexes and/or titanium-, zirconium- and/or hafnium guanidinate complexes and organo aluminium and/or organic zinc compounds, a coordinative chain transfer polymerization (CCTP) process employing the catalyst composition as well as long chain aluminium alkyls and subsequent alcohols obtained by such process.

The polymerization of olefins with the use of Ziegler-Natta catalysts is an established technique known since the early 1950s and is widely applied in industry. Ziegler-Natta catalysts are based on transition metal compounds, especially titanium and organoaluminium compounds. Numerous metal complexes have been described in the literature as catalysts for olefin polymerization, among the publications are literature references teaching amidinate and guanidinate metal complexes and their use as polymerization catalysts such as WO 97/45434, U.S. Pat. Nos. 5,777,120 and 5,502,128. Bis(trimethylsilyl)benzamidinate zirconium dichlorides are taught by D. Herskovics-Korine in JOURNAL OF ORGANOMETALLIC CHEMISTRY, vol. 503, no. 2, 15 Nov. 1995, pages 307-314 as active catalysts in presence of a co-catalyst (methylaluminoxane, MAO) for polyethylene (PE) production. The use of Titanium monoamidinate-MAO catalysts for the polymerization of propene, styrene, and 1,3-butadiene is taught by Liguori et al. in MACRO-MOLECULES, vol. 36, no. 15, 1 Jul. 2003, pages 5451-5458. M. Zhou et al. in JOURNAL OF ORGANOMETALLIC CHEMISTRY, vol. 692, no. 23, 6 Oct. 2007, pages 5195-5202 teach the use of tris guanidinato zirconium and hafnium complexes as catalysts for PE production in presence of a co-catalyst MAO or Et2AlCl. A further publication of M. Zhou et al. in INORGANIC CHEMISTRY COMMUNICATIONS, vol. 10, no. 11, 18 Oct. 2007, pages 1262-1264 relates to the synthesis and structure of non-symmetric zirconium guanidinato dimer complexes and their use in PE production in combination with MAO, MMAO (modified MAO) and Et2AlCl. A review by S. Collins of different amidinate and guanidate catalysts and their use as polymerization catalysts is published in COORDINATION CHEMISTRY REVIEWS, vol. 255, no. 1-2, 1 Jan. 2011, pages 118-138. None of the above references is concerned with CCTP yielding oligomers of relatively low molecular weight and allowing the production of long chain alcohols or alpha olefins. Moreover, none of the catalyst systems is capable of producing Al-terminated oligomers.
A great variety of catalysts capable of catalyzing coordinative chain transfer polymerization (CCTP) has been proposed in the literature. CCTP is commonly used to control and modify molecular weights of polymers. These transition metal based catalysts are typically used together with co-catalysts which usually act as chain transfer agents. Suitable co-catalysts include alkyl zinc, alkyl aluminium, alkyl aluminium halides and alkyl alumoxanes, commonly used together with inert, non-coordinating ion forming compounds (activator), Lewis and Brönstedt acids and mixtures thereof. Such prior art processes are disclosed in W. P. Kretschmer et al.; Chem. Eur. J. 2006, 12, 8969-8978 and S. B. Amin, T. J. Marks; Angew. Chem. 2008, 120, 2034-2054 and Zinck et al.; Chem. Rev. 2013; DOI: dx.doi.org/10.1021/cr300289z.
One characteristics of CCTP is that polymer chains are end-capped with the respective main group metal of the co-catalyst and can be further functionalized (M. Bialek, J. Polym. Sci.: Part A: Polym. Chem. 2010, 48, 3209-3214 and W. P. et al., Dalton Trans. 2010, 39, 6847-6852).
CCTP typically requires the use of a metal complex as catalyst, a co-catalyst and optionally an activator. In the understanding of the present invention the co-catalyst is a chain transfer agent and may optionally but not necessarily be an activator at the same time. The activator may be for example a compound different from the chain transfer agent and not functioning as a chain transfer agent. Such activator in the understanding of the invention is under above circumstances not called a co-catalyst and only an activator.
Catalyst systems used in CCTP are often prone to ligand transfer from the catalyst onto the co-catalyst which results in a decreased activity (W. P. Kretschmer, B. Hessen, A. Noor, N. M. Scott, R. J. Kempe, Organomet. Chem. 2007, 692, 4569-4579). Especially, at high co-catalyst to catalyst ratios the catalyst activity is remarkably decreased. Hence, all known catalyst systems suffer from un-wanted olefin production due to β-hydride elimination. It is therefore an objective of the present invention to provide highly active catalysts showing only minor β-hydrid elimination and accordingly less side products (I. Haas, W. P. Kretschmer, R. Kempe, Organometalics 2011, 30, 4854-4861). Besides the total chain transfer efficiency should be close to 100%. In addition the catalyst should be capable of operating at high co-catalyst to catalyst ratios thereby suppressing β-hydrid elimination in view of the fact that the co-catalyst acts as chain transfer agent.
EP 0329891 A2 for instance discloses certain low molecular weight polyethylene alcohols having an average chain length of from about 20 to about 500 carbon atoms and a polydispersity of 1.04 to 1.20 and their conversion to end-functionalized polymers by introducing a functional group which replaces the hydroxyl group of the alcohol. The following functional groups are taught: halogen, alkanolamine, carboxyl, thiol, amine, quaternized amine radical, amide, quaternized dialkylamine, amine oxide, silyl and others.
The object of the present invention is to find stable highly active and selective metal complexes which are capable of polymerizing or co-polymerizing olefins and to finally transfer the produced carbon chain onto a co-catalyst. The co-catalyst thereby acts as a chain transfer agent and is functionalized with the carbon chain after the transfer. Subsequent to the transfer the obtained molecules can be derivatized via oxidation and hydrolyzation to yield functionalized carbon chains, in particular hydroxy terminated carbon chains. A further objective of the present invention is to provide a catalyst which can be prepared in an easy and economical fashion.

Amidinate and guanidinate complexes, their use as chain transfer polymerization catalysts and long chain alcohols obtained by such process


A method for remanufacturing an electronic assembly includes removing a first portion of an assembly housing to expose an underside of an enclosed circuit assembly. One or more solder joints on the underside of the circuit assembly are associated with at least one component that is also affixed to a portion of the housing. The opened electronic assembly is lowered onto a desoldering fixture having a plurality of solder pots configured to encompass, and thus desolder, the solder joints associated with the component that is affixed to a portion of the housing. Once the affected solder joints are melted, the remaining portion of the housing and the component affixed thereto may be lifted away, exposing the top surface of the circuit assembly for analysis, repair, and or adjustment.

With the advent of integrated electronics, electrical circuits have largely eliminated mechanical and electromechanical features in many applications, reducing the maintenance and adjustment chores associated with such applications. However, these electrical circuits as well as the mechanical aspects of the circuit housing, attachment points, and so on, may still occasionally require maintenance, adjustment, or even replacement. For example, power circuits may be exposed to excess heat and may be degraded. Vibration and other mechanical forces may affect the circuits and/or their housings or their connections to other circuit elements. However, due to the relative permanence of integrated circuit assemblies, these assemblies are not often configured for easy disassembly.
Compounding this problem, integrated circuits and other electrical assemblies are often connected to other circuitry via metallic solder because of its strength as an adhesive as well its relatively low impedance to the flow of electrical current. Solder enters a liquid state at a much lower temperature than many other metals, allowing ease of application, and remains conductive through repeated thermal cycling.
With the advent of the PCB (printed circuit board), the use of solder became widespread as a means of connecting components to PCB's. A PCB typically comprises a fiber or fiberglass board covered with metallic circuit traces, having components attached to the board in prescribed locations to contact the traces. Typically, such components have one or more "pins" or leads attached to the component that extend, parallel to one another, in one direction. During assembly, these leads are inserted through holes in the PCB (and in the overlying metallic traces) and are soldered to the traces. Often, the traces are shaped into "pads" or contacts at the points of insertion to ensure better attachment and conductivity between the component pins and the traces. PCBs made in this way tend to be cost effective, robust and reliable.
As noted above, however, electronic assemblies sometimes require disassembly, and such disassembly may require removal of one or more components from the board. It is often advantageous to affix certain assemblies to a housing or other nearby structure for purposes of heat transfer, mechanical support, and so on. However, by joining the board and housing in a semi-permanent manner, this practice can render one side of the board inaccessible, requiring desoldering of components to allow the remainder of the board to be accessed for inspection and repair.
Most solders melt at temperatures that are high enough to damage the housings and internal circuitry of many electrical components. In addition, mechanical stress and strain imposed during insertion and removal of components may weaken or damage components. Ideally, circuit components should be desoldered without damaging the components in question to the extent they are salvageable, and without causing damage to any surrounding components through the application of excess heat or mechanical strain.
Thus, desoldering and disassembly must be executed with care. At the same time, for large scale remanufacturing operations, efficiency is important, and removing and replacing multipin devices from PCBs by hand is still a slow and tedious process. Often, it is performed using a soldering iron and braided wick, or with a vacuum soldering iron to melt and remove solder. However, these methods require skill and care to prevent damage to the PCB, and the complexity and failure rate of these techniques essentially preclude efficient large-scale use.
Although a complete solution to this problem has never been found, certain attempts have been made over the years. For example, U.S. Pat. No. 4,506,820 to John Brucker describes a limited system for desoldering multipin components from printed circuit boards. According to the system of the '820 patent, a large shallow solder pot, in combination with a flexible mask, is used to apply molten solder to a selected area of a printed circuit board so as to desolder a selected device. Essentially, the '820 mask is applied to all surfaces of the board for which desoldering is not desired. In this manner, the components at the masked locations will in principle remain soldered when the entire assembly is exposed to the solder bath in the large shallow solder pot, and any unmasked components will be desoldered. However, in addition to the need to supply a pool of molten solder as large as the entire PCB, the '820 method also requires the design, creation, application, and removal of masks, with all attendant costs and complications. In addition, regardless of whether the '820 masks function properly during a given use, they do not appear to provide a robust and cost-effective solution for repetitive desoldering tasks.

Electronic assembly remanufacturing system and method


The invention involves a process for controlling the rotational speed of a drive motor during a start-up period, in a drive train, containing at least one starter element that can be coupled to the drive motor, in a rotationally fixed manner, in the form of a hydrodynamic coupling, containing a primary blade wheel and a secondary blade wheel, which form together at least one toroid-shaped working space. According to the invention, the rotational speed of the drive motor is set as a function of the power that can be consumed by the hydrodynamic coupling. The consumable power can be controlled or regulated.

The invention involves a process for controlling the rotational speed of a drive motor.
Processes for controlling the rotational speed of a drive motor, in particular, during the start up period, in a drive train, in particular for use in motor vehicles, including at least one drive motor and a start up element that can be coupled with it, at least indirectly, are known in a multitude of different embodiments with regard to the variables triggering the controlling operation, i.e. the input variables of the control device, the dependence of the control variables on other variables and the correcting variables. It is generally known that, in drive trains of motor vehicles, including an intemal combustion engine, especially Otto or diesel engines, and a start up element that can be mechanically or hydrodynamically coupled to them, as a correcting variable for the rotational speed control of the drive motor, a variable is formed that at least indirectly characterizes the adjustment of the power output stage of the drive motor—throttle valve or injection nozzle—and the adjustment device—throttle valve or injection nozzle—is triggered in this way. Reference is made to, as a representative example, "Diesel injection technology" by Bosch, VDI-Publishers 1993, pages 162-on. Start up period is understood here to be the time span of the operating period of the drive train, which is characterized by a run-up of the drive unit from the start, i.e. the start up of the drive motor until the change into a higher gear level in bypassing the hydrodynamic starter element.
When hydrodynamic couplings are used as a start up element in motor vehicles, they are designed in such a manner that a filling of the hydrodynamic coupling can occur automatically during the start up period, for example, depending on the rotational speed of the drive motor or retarded from it. However, it has been shown that dynamic systems behavior becoming set in this way, characterized by the characteristic line of the coupling, is characterized in that high torque can only be transferred at high rotational speeds of the drive motor. This means, however, for embodiment of the drive motor as an internal combustion engine, that the consumption-optimized range in the performance characteristics of the motor, and thus an operating method that is low in hazardous materials, is not achieved and furthermore, for the transfer of high torque a correspondingly high power drive motor is always necessary.

Method for regulating the speed of a drive motor


The present invention discloses a high light-extraction efficiency LED structure, wherein metallic pads and metallic mesh wires made of an aluminum-silver alloy are formed on an LED, whereby the high-reflectivity aluminum-silver alloy makes the light incident on the metallic pads and metallic mesh wires reflected once more or repeatedly and then emitted from the surface or lateral side of the LED, wherefore the present invention can decrease the light loss and increase the light-extraction efficiency.

Refer to FIG. 1 for a conventional light-emitting diode (LED), wherein an N-type gallium nitride layer (n-GaN) 2, a multi-layer quantum well (MQW) 3, a P-type gallium nitride (p-GaN) 4 are sequentially epitaxially grown on a substrate 1; then a P-type metallic pad (p-Pad) 5 and an N-type metallic pad (n-Pad) 6 are coated on the abovementioned epitaxial layers. If the LED is to be used as a high-power and large-size LED, metallic mesh wires 7 and 8 are simultaneously coated on the epitaxial layers during coating the P-type metallic pad 5 and the N-type metallic pad 6. For a high-power and large-size LED, a high-reflectivity reflecting layer 9 is further coated on the grinded and polished substrate 1 to increase the brightness of the LED by reflection.
In a high-power and large-size LED, the P-type metallic pad 5, the N-type metallic pad 6 and the metallic mesh wires 7 and 8 are usually uniformly distributed on the light-emitting region and occupy a considerable area. The conventional P-type metallic pad 5, N-type metallic pad 6 and metallic mesh wires 7 and 8 are usually made of indium tin oxide (ITO), nickel/gold, or chromium/gold. However, ITO has a problem of peel-off and is likely to react with silver. When cooperating with silver, the nickel/gold or chromium/gold has a reflectivity of only 50-60%, absorbs a considerable amount of light, and results in an unneglectable light loss, which not only decreases the brightness of LED but also generates waste heat. Thus, the service life of LED is decreased by high temperature.

High light-extraction efficiency light-emitting diode structure


A method for manufacturing an electronic device and an electronic device are disclosed. In an embodiment the method comprises forming an opening in an isolation layer, isotropically etching the opening thereby forming an extended opening with curved sidewalls, and forming a conductive material in the opening.

Generally, discrete transformers and optocouplers are used to transmit signals from one electrical circuit to another electrical circuit without direct electrical contact between the two electrical circuits. However, discrete transformers and optocouplers are relatively large, heavy, and expensive, and in the case of optocouplers, aging may be a problem.
Another way to transmit signals from one electrical circuit to another electrical circuit without direct electrical contact is a coreless transformer. While a discrete transformer comprises a core to direct the magnetic flux, the coils of a coreless transformer can be placed close enough to each other so that the core can be spared.

Method for fabricating a coil by way of a rounded trench


A method of and system for detecting a measurement error. The method includes: receiving measurement data from a measurement unit and user expression data from a user; corresponding each of the received measurement data and expression data to any one section of a plurality of sections; and checking whether or not the corresponding two sections are consistent with each other, to detect an error of any one of the measurement data and the expression data when they are not consistent. The system includes: a measurement unit for measuring measurement data; a user inputting unit for receiving expression data from a user; a memory for storing a plurality of sections classifying values of the measurement data and the expression data; a section detecting unit for corresponding each of the measurement data and the expression data to any one of the stored plurality of sections; and an error detecting unit for checking whether or not the corresponding two sections are consistent, to detect an error of any one of the measurement data and the expression data when they are not consistent.

1. Field of the Invention
The present invention relates to a method of and system for detecting a measurement error, and more particularly, to a method of and system for detecting a measurement error in which measurement unit data and user expression data for the same environment or the same item are cross-checked to detect a measurement error, thereby warning a user or providing the user with feedback information depending on the detected measurement error.
2. Description of Related Art
Recently, as concerns about personal health have increased, many people have begun to enjoy regular exercise such as running, walking and the like so as to maintain health. During exercise, an exerciser often desires to know exactly how much exercise he or she has accomplished by measuring for example, calorie consumption. Accurate measures of such information help an exerciser meter his or her exercise and thus maintain his or her health.
Accordingly, measurement devices for simply and conveniently measuring an exercise amount such as calorie consumption have been recently manufactured and used. However, the measurement devices have a drawback in that when measurement data such as calorie consumption has an error, a health management based on the measurement data is deteriorated.

Method and system for detecting measurement error


Processes for making ivalent germanium and tin compounds are provided. The divalent germanium and tin compounds have been found to be efficient catalysts for the formation of polyurethanes.

Coating manufacturers have achieved significant progress in developing novel components for polyurethanes to improve coating properties, although a need remains for novel catalyst systems. The usual catalysts for forming polyurethanes are dibutyltindilaurate and tertiary amines. Dialkyl and trialkyltin derivatives, classes of the compounds to which dibutyltindilaurate belongs, have been discussed as having some issues regarding human toxicity. See, for example, Boyer, I. J., Toxicology, 1989, 55, 253 and Lytle, T. F.; Manning, C. S.; Walker, W. W.; Lytle, J. S.; Page, D. S., Appl. Organomet. Chem., 2003, 17, 653. Divalent tin compounds as disclosed herein, which do not have alkyl-tin bonds, have now been found to be suitable as catalysts for polyurethane formation.
Organometallics of the group 14 elements, particularly dibutyltin derivatives, are known to catalyze transesterification, transcarbamoylation and urethane formation. While there has been progress in development of novel components for polyurethanes to improve coating properties, a need remains for novel catalyst systems. Typical catalysts for processes including transesterification, transcarbamolylation and urethane formation are dibutyltindilaurate and tertiary amines. Dialkyl and trialkyltin derivatives, classes of the compounds to which dibutyltindilaurate belongs, have some toxicity to humans; therefore, less toxic catalysts are desired.
Jousseaume, B. et al., ("Air Activated Organotin Catalysts for Silicone Curing and Polyurethane Preparation" (1994) Organometallics 13:1034), and Bernard, J. M. et al. (U.S. Pat. No. 6,187,711) describe the use of distannanes as latent catalysts.
Co-owned and co-pending U.S. Pat. Applications (CL-3191, CL-3464 and CL-3193), all hereby incorporated by reference in their entirety, describe different classes of tin and germanium compounds useful as catalysts. (CL-3191) describes divalent tin compounds stabilized by phenoxy groups with bulky ortho-substituents. (CL-3193) describes quadrivalent tin and germanium compounds containing more than one triorganylsilyl groups connected to tin or germanium.

Processes for making stabilized divalent germanium and tin compounds


A system, such as an extension service, receives a first public key that is derivable based at least in part on a secret that is shared between at least a first device and a second device. The system, in an embodiment, derives a cryptographic key based at least in part on the first public key and transmits a second public key that enables another system to derive the cryptographic key. In an embodiment, the cryptographic key is a symmetric key and the system lacks access to a first private key that corresponds to the first public key.

The security of computing resources and associated data is of high importance in many contexts. As an example, networks of computing devices may be utilized to provide a robust set of services to their users. In many cases, a service of a computing resource service provider provides various types of functionality to a plurality of client and utilizes various types of computer security measures to, for example, protect from unauthorized access to communications between a service and a client. A cryptographic key, such as a symmetric key, can be used by a server and client to communicate with cryptographically verifiable assurances of confidentiality, authenticity, and/or integrity.
As described above, a service can be used to provide various types of functionality to a client, and in some cases, there may be advantages to cost and efficiency of a system to off-load tasks of the service to another entity, such as a child service or micro-service. For security reasons, it may be desirable to not expose a cryptographic key that is accessible by a server and a client to another entity such as a child service or micro-service. Furthermore, it may be desirable to not require a client to re-provision data storage systems to support communications with a child service or micro-service.

Mechanism to allow third party to use a shared secret between two parties without revealing the secret


A tissue stimulation system and computer software and method of operating the system is provided. An array of electrodes is placed contact with tissue of a patient (e.g., neural tissue), and electrical current is conveyed within the electrode array, thereby creating a stimulation region in the tissue. Electrical current is shifted between cathodes of the electrode array in incremental steps over a range, thereby causing displacement of the stimulation region at substantially uniform distances over the incremental steps. The electrical current may be shifted between the cathodes in accordance with a sigmoid-like function of a position of the stimulation region. A navigation table containing a series of states and corresponding gradually and non-uniformly changing electrical current values can be accessed, in which case, the electrical current may be shifted between the cathodes by incrementing through the states of the navigation table.

Spinal cord stimulation (SCS) is a well-accepted clinical method for reducing pain in certain populations of patients. Spinal cord stimulator and other implantable tissue stimulator systems come in two general types: radio-frequency (RF)-controlled and fully implanted. The type commonly referred to as an "RF" system includes an external transmitter inductively coupled via an electromagnetic link to an implanted receiver-stimulator connected to one or more leads with one or more electrodes for stimulating tissue. The power source, e.g., a battery, for powering the implanted receiver, as well as control circuitry to command the receiver-stimulator, is contained in the external controller—a hand-held sized device typically worn on the patient's belt or carried in a pocket. Data/power signals are transcutaneously coupled from a cable-connected transmission coil placed over the implanted receiver-stimulator. The implanted receiver-stimulator receives the signal and generates the stimulation. In contrast, the fully implanted type of stimulating system contains the control circuitry, as well as a power supply, e.g., a battery, all within an implantable pulse generator (IPG), so that once programmed and turned on, the IPG can operate independently of external hardware. The IPG is turned on and off and programmed to generate the desired stimulation pulses from an external programming device using transcutaneous electromagnetic or RF links.
Whether an RF-controlled or fully implanted system is used, the electrode leads are implanted along the dura of the spinal cord. Individual wires within one or more electrode leads connect with each electrode on the lead. The electrode leads exit the spinal column and attach to one or more electrode lead extensions, when necessary. The electrode leads or extensions are typically tunneled along the torso of the patient to a subcutaneous pocket where the IPG or RF receiver-stimulator is implanted. The IPG or RF transmitter can then be operated to generate electrical pulses that are delivered, through the electrodes, to the dorsal column and dorsal root fibers within the spinal cord. The stimulation creates the sensation known as paresthesia, which can be characterized as an alternative sensation that replaces the pain signals sensed by the patient. Individual electrode contacts (the "electrodes") are arranged in a desired pattern and spacing in order to create an electrode array.
In order to achieve an effective result from SCS, the lead or leads must be placed in a location, such that the electrical stimulation will cause paresthesia. The paresthesia induced by the stimulation and perceived by the patient should be located in approximately the same place in the patient's body as the pain that is the target of treatment. If a lead is not correctly positioned, it is possible that the patient will receive little or no benefit from an implanted SCS system. Thus, correct lead placement can mean the difference between effective and ineffective pain therapy. Once the leads are correctly positioned, a "fitting procedure" is performed by electronically programming the electrode array with a set of parameters that best addresses the painful site. Thus, electrode programming may be used to pinpoint the stimulation area correlating to the pain. Such electrode programming ability is particularly advantageous after implantation should the leads gradually or unexpectedly move, thereby relocating the paresthesia away from the pain site. With electrode programmability, the stimulation area can often be moved back to the effective pain site without having to reoperate on the patient in order to reposition the lead and its electrode array.
Electrodes can be selectively programmed to act as anodes (positive), cathodes (negative), or left off (zero). Other parameters that may be controlled or varied in SCS include the frequency of pulses provided through the electrode array, pulse width, and the amplitude of pulses delivered. Amplitude may be measured in milliamps, volts, etc., as appropriate, depending on whether the system provides stimulation from current sources or voltage sources. With some SCS systems, and in particular, SCS systems with independently controlled current or voltage sources, the distribution of the current to the electrodes (including the case of the pulse generator or receiver, which may act as an electrode) may be varied such that the current is supplied via numerous different electrode configurations. In different configurations, the electrodes may provide current (or voltage) in different relative percentages of positive and negative current (or voltage). Moreover, there may be some electrodes that remain inactive for certain electrode configurations, meaning that no current is applied through the inactive electrode. The number of electrodes available, combined with the ability to generate a variety of complex stimulation pulses, presents a huge selection of electrode configurations and electrical pulse parameters (together referred to as "sets of stimulation parameters") to the user.
To facilitate such selection, the physician or clinician generally programs the IPG, external controller, and/or external patient programmer through a computerized programming station or programming system. This programming system can be a self-contained hardware/software system, or can be defined predominantly by software running on a standard personal computer (PC). The PC or custom hardware can have a transmitting coil attachment to actively control the characteristics of the electrical stimulation generated by the IPG or transmitter to allow the optimum stimulation parameters to be determined based on patient feedback and for subsequently programming the IPG, external controller and/or external patient programmer with the optimum stimulation parameters.
A known practice for current-controlled stimulation systems is to select a few basic electrode configurations by selecting the polarity (anode, cathode, or inactive) and fractionalized current (percentage of current) sourced or sunk by each electrode either manually or automatically, and then refining these basic electrode configurations by gradually adjusting the polarity and fractionalized current flowing through the electrodes.
For example, FIG. 1 illustrates four different electrode configurations (using 16 electrodes) that can be tested. Each row specifies the polarity on each electrode. In exemplary electrode configuration 1, electrode 3 is an anode, electrode 2 is a cathode, and the remaining electrodes are inactive, with electrode 3 sourcing 100% of the current and electrode 2 sinking 100% of the current. In exemplary electrode configuration 2, electrode 13 is an anode, electrode 5 is a cathode, and the remaining electrodes are inactive, with electrode 13 sourcing 100% of the current and electrode 5 sinking 100% of the current. In exemplary electrode configuration 3, electrodes 6 and 14 are anodes, electrodes 3 and 11 are cathodes, and the remaining electrodes are inactive, with electrodes 6 and 14 respectively sourcing 45% and 55% percent of the current, and electrodes 3 and 11 respectively sinking 30% and 70% of the current. In exemplary electrode configuration 4, electrodes 1, 6, 9, and 14 are anodes, electrodes 3, 4, 11, and 12 are cathodes, and the remaining electrodes are inactive, with electrodes 1, 6, 9, and 14 respectively sourcing 15%, 21%, 22%, and 42%, and electrodes 3, 4, 11, and 12 respectively sinking 15%, 21%, 22%, and 42% of the current. Each of the basic electrode configurations creates a stimulation region having a nominal position within the spinal cord tissue.
Each of the basic electrode configurations can be refined by gradually moving the current sourced or sunk by the anodes and cathodes to adjacent electrodes, thereby electronically steering the stimulation region relative to the nominal position to determine the optimum refined electrode configuration. Electrical steering can be performed in accordance with a steering or navigation table. For example, as shown in FIG. 2, a portion of an exemplary navigation table can be used to gradually modify the exemplary basic stimulation set 2 of FIG. 1. As can be seen, exemplary electrode configuration 2 is represented by stimulation set 291 in FIG. 2. Current can be incrementally moved from cathode electrode 5 to cathode electrode 6 as one steps downward through the navigation table, and from cathode electrode 5 to cathode electrode 4 as one steps upward through the navigation table. The step size of the current should be small enough so that steering of the current does not result in discomfort to the patient, but should be large enough to allow refinement of a basic electrode configuration in a reasonable amount of time. In the illustrated embodiment, the current step size is 5%.
While the navigation table illustrated in FIG. 2 dictates that the current will be shifted between electrodes in uniform current steps, the stimulation region will actually move in non-uniform steps (i.e., the distance moved between steps is not uniform). This non-uniformity may cause some of the portions of the navigation table to be largely redundant in terms of clinical effect, while other portions of the navigation table may move the stimulation region in relatively large steps, potentially skipping useful electrode configurations. This hypothesis gains support from a computational model and anecdotal reports from the field. The model suggests that shifting current between anodes only minimally moves the stimulation region (<5% of movement of the stimulation region), and that much of the stimulation region movement occurs when shifting current between adjacent cathodes. Reports from the field also suggest that most of the paresthesia changes occur during shifts in current between the cathodes. The model also indicates that movement of the stimulation region during cathode current shifting is not linear. For example, the model predicts that nearly half of the stimulation region movement occurs when current is shifted between 60/40 and 40/60 splits in current percentage between two cathodes. That is, half of the movement of the paresthesia change may occur in only four navigation steps assuming a current shifting resolution of 5%. Thus, some portions of the navigation table may have too high of a current shifting resolution, thereby unnecessarily increasing navigation time, while other portions of the navigation table may have too low of a current shifting resolution, thereby ignoring potentially relevant electrode configurations.
There, thus, remains a need for an improved method and system for shifting current between electrical stimulation electrodes.

System and method for uniformly displacing a region of neural stimulation

Boston Scientific Neuromodulation Corporation


Disclosed are a composite material having an anti-wear property and a process for producing the same. The composite material includes a matrix of a low melting point Sn alloy having a melting point of from 80.degree. to 280.degree. C., and metallic dispersing particles dispersed in the matrix in an amount of from 10 to 50% by volume. When the composite material is utilized to make a rough mold for preparing a prototype, it sharply improves the anti-wear property of the rough mold, and it can be re-used for a plurality of times without adversely affecting the sharply improved anti-wear property. The composite material provides the advantages effect best when the metallic dispersing particles are Fe-C alloy dispersing particles and/or Fe-W-C alloy dispersing particles which were subjected to a surface treatment including an Sn or Ni electroplating followed by a ZnCl.sub.2 .cndot.NH.sub.4 Cl flux depositing.

1. Field of the Invention
The present invention relates to a composite material having an anti-wear property.
2. Description of the Related Art
There has been a low melting point alloy which exhibits a good flowing ability and a superb molding ability when heated and melted. The low melting point alloy is used in order to produce a rough mold for preparing a prototype by casting, for instance, it is used to produce a rough pressing die, a rough injection molding mold or the like by casting.
As the low melting point alloy, there is a binary eutectic alloy including Bi and Sn, e.g., a low melting point Bi-Sn eutectic alloy (hereinafter referred to as "Conventional Example Alloy No. 1"). Further, there is another low melting point alloy (hereinafter referred to as "Conventional Example Alloy No. 2") which is set forth in Japanese Unexamined Patent Publication (KOKAI) No. 2-25,533. Conventional Example Alloy No. 2 is made by adding Sb to the Conventional Example Alloy No. 1, and it is precipitated as solid solution. These two low melting point alloys, Conventional Example Alloy No. 1 and Conventional Example Alloy No. 2, have a melting point of about 139.degree. C. and about 200.degree. C., respectively, and they are based on the binary eutectic alloy.
Three pressing dies were prepared by casting by using Conventional Example Alloy No. 1, Conventional Example Alloy No. 2 and a commercially available alloy including Zn as the principal component (hereinafter referred to as Conventional Example Alloy No. 3) in order to evaluate the advantages and disadvantages of the 3 alloys. Conventional Example alloy No. 3 is made by MITSUI KINZOKU KOGYO CO., LTD. and sold under a trade name of "ZAS," and it has a melting point of 380.degree. C. approximately. The evaluation was conducted as follows: The 3 conventional alloys were made into test pieces in a rectangular parallelepiped having a size of 15 mm.times.15 mm.times.120 mm, and the test pieces were assembled in a pressing die as illustrated in FIG. 6. Then, a plurality of galvanized steel sheets having a thickness of 1.6 mm were pressed with the 3 pressing dies, and cross sectional worn areas of the test pieces illustrated in FIG. 7 were measured for wear amounts (in mm.sup.2) with respect to the number of pressing shots in order to examine the anti-wear property of the 3 conventional alloys. As a result, it was found that Conventional Example Alloy No. 1 and Conventional Example Alloy No. 2 reduce the time required for producing the pressing die (or the test pieces) and are superior in the working ability and the manufacturing cost because they have a melting point far lower than that of Conventional Example No. 3. However, it was found that they are far inferior in the anti-wear property. For instance, as illustrated in FIG. 1, the anti-wear property of the test pieces made from Conventional Example Alloy Nos. 1 and 2 (designated with "a1" and "a2" curves, respectively, in the drawing) were remarkably inferior to that of the test pieces made from Conventional Example Alloy No. 3 (designated with "a3" curve in the drawing).

Composite material having anti-wear property and process for producing the same


A transducerless position determining system and method of using the same for determining the relative position of a mechanical member or component which is driven by an electric motor within an electromechanical system. The transducerless position determining system includes a microcontroller with a software model that simulates the acceleration, deceleration and velocity characteristics of the electric motor as a function of applied voltage thereto and the load characteristics of the electromechanical system. The applied voltage is sampled electronically to monitor its amplitude level, and microcontroller software and associated circuitry is used to accurately detect application and removal of the applied voltage to the electric motor. While taking into account the simulated acceleration and deceleration of the electric motor, the software model controls a software-based variable speed counter which increments and decrements relative to the direction of motor operation at a rate of speed proportional therewith. The proportional data generated by the variable speed counter correlates with the relative position of the movable component, and can be converted and scaled for appropriate display purposes. The system uses a predetermined reference position of the mechanical component within the electromechanical system to correlate re-synchronization of the software model for the electric motor.

The instant invention is related generally to position determining systems, and more specifically to a position determining system which does not require the use of an electronic position indicating transducer for determining the relative position of a movable member or component within an electromechanical system.
Generally, it is often desirable to monitor the position of a movable mechanical component or subsystem within a larger system. In an electromechanical system, this is conventionally accomplished electronically, through the use of an electronic position indicating transducer. Such electronic position indicating transducers may be of any of a variety of configurations (i.e., resistive, capacitive, optical, etc., either rotary or linear). Nearly all such transducers have an associated cost therewith which may be significant in relation to the size of the electromechanical system in which it is used. In many applications, such as one where the environment may be hostile to the transducer, or where the transducer is prohibitively expensive, it may be quite desirable, if possible, to eliminate the transducer altogether.
For instance, in one such application related to the use of personal watercraft devices, it is desirable to measure the position of a rotary shaft which controls the position of the watercraft's jet nozzle. Altering the position of the jet nozzle changes the attitude of the craft in the water, thus achieving the function of trim. This is analogous to adjusting the "trim" on other boats and marine vehicles so equipped with this function. In relation to such personal watercraft, cost is a significant concern, as the electromechanical system involved is not of large scale. Also, there are significant reliability concerns over the use of such a transducer for measuring the position of the jet nozzle, since such personal watercraft are commonly subjected to the harsh marine environment of substantial vibration and corrosive salt water. Nevertheless, on personal watercraft equipped with such a trim function, it is desirable for the operator of such craft to have knowledge of the position of the jet nozzle at all times. For these reasons, it can be seen that it would be particularly advantageous to provide a position determining system for use in such application which does not require the use of such a position indicating transducer. To this end, the instant invention, as described herein and throughout the appended claims, solves the above problems by providing a transducerless position determining system and method of using the same for applications, such as that described above, where it may not be desirable to incorporate such a transducer.

Transducerless position determining system and method for the same


A method of making a ceramic arc tube for a metal halide lamp comprises the steps of forming as an integral unit a hollow body having one open end and a substantially closed end. The substantially closed end includes an outwardly extending capillary tube having an electrode receiving aperture therein that communicates with the hollow body. An end cap is then formed for closing the open end. The end cap comprises an annular portion and an extending capillary tube, The end cap is fitted into the open end of the hollow body to form a pre-assembly. The pre-assembly is then fired to seal the end cap to the hollow body to form an assembly and the assembly is subsequently fired to sinter the same.

Ceramic arc tubes of materials such as polycrystalline alumina with one or more additives to control grain size have been used as the discharge vessel or arc tube for high-pressure sodium lamps. Recently, such arc tubes have been employed with metal halide lamps. See, for example, U.S. Pat. No. 5,424,609. Such arc tubes have comprised 5 piece structures including a cylindrical body, a pair of end closures or buttons, and a pair of electrode receiving rods or capillary tubes sealed to the buttons. Manufacture of such arc tubes required extrusion or pressing of the components, as well as multiple assembly and heat treatment steps that increased handling and, therefore, cost.
Additionally, three piece structures have been proposed. In U.S. Pat. No. 4,766,347 there is shown an arc tube having only a ceramic body with electrode receiving rods sealed directly therein. U.S. Pat. No. 5,426,343 discloses a three-piece structure wherein a sealing button has an extending electrode rod receiving member integral therewith.
All of these approaches require extra heating and handling steps.

Method of making a ceramic arc tube for metal halide lamps


Disclosed is a wireless communication apparatus for receiving a code-spread transmission signal. The wireless communication apparatus includes: an RF section; and a baseband section, wherein, in the baseband section, despreaders of an integral submultiple, which is 1/n1, of the number of chips of a spread code are arranged in parallel, and there is provided a propagation measurement section that measures a propagation channel by using the plurality of despreaders a plurality of times in a time-division manner and performing despread of each period corresponding to a chip rate of the spread code.

1. Field of the Invention
The present invention relates to a wireless communication apparatus, a wireless communication method, a propagation measurement apparatus and a propagation measurement method for receiving a spectrum-spread transmission signal. In particular, the present invention concerns a wireless communication apparatus, a wireless communication method, a propagation measurement apparatus and a propagation measurement method for performing propagation measurement using a preamble section of the spectrum-spread transmission signal.
More specifically, the present invention relates to a wireless communication apparatus, a wireless communication method, a propagation measurement apparatus and a propagation measurement method for performing propagation measurement by despread of each spread code in the baseband section having a clock frequency not more than a chip rate in an RF section. In particular, the present invention concerns a wireless communication apparatus, a wireless communication method, a propagation measurement apparatus and a propagation measurement method for performing propagation measurement using a plurality of despreaders that despread each chip of a short code, in consideration of a trade-off between speed enhancement and circuit scale and power consumption.
2. Description of the Related Art
Canonical standards concerning wireless networks can include IEEE (The Institute of Electrical and Electronics Engineers) 802.11 (e.g., see non-patent document 1), HiperLAN\2 (e.g., see non-patent document 2 or 3), IEEE802.15.3, and Bluetooth communication, for example. The IEEE802.11 has enhanced standards such as IEEE802.11a, IEEE802.11b, etc. depending on differences of wireless communication systems and frequency bands.
Further, in recent years, so-called "ultra-wideband (UWB) communication" for carrying out wireless communication that uses a very wide frequency band such as 3 GHz-10 GHz is attracting attention as a short-distance, ultra-high-speed wireless communication system, and is expected to be put to practical use (e.g., see non-patent document 4). At present, a data transmission system having a packet structure including a preamble is being developed as an access control system of ultra-wideband (UWB) communication, in IEEE802.15.3 and the like.
The UWB communication has high time resolution by employing very narrow pulses, and this property enables "Ranging" for radar and positioning. In particular, recent UWB communications can include high-speed data transmission exceeding 100 Mbps (e.g., see patent document 1) along with the original ranging function (e.g., see patent document 1).
It is anticipated that WPAN (Wireless Personal Access Network) represented by the UWB as short-distance communication will be employed in various kinds of household electrical appliances and CE (Consumer Electronics) devices in the feature, and home networks and P-to-P transmission exceeding 100 Mbps between CE devices are expected to be achieved. If the use of millimeter wave bands becomes widespread, it becomes possible to achieve short-distance wireless communication exceeding 1 Gbps and also an ultra-high-speed DAN (Device Area Network) for short-distance communication including a storage device etc.
A recent trend is to put SS (Spread Spectrum) based wireless LAN systems to practical use. With the spread spectrum, even if there is communication using the same frequency in the neighborhood, a C/I required for enabling normal communication can be set below 0 dB. That is, even if a communication apparatus detects a signal of another apparatus at the same level as that of the apparatus, the apparatus can still communicate. In particular, the spread spectrum is convenient to use in the UWB since the occupied bandwidth of the UWB is originally much wider than the required bit rate.
The SS systems include the DS (Direct Spread) system. According to this system, the transmission side multiplies an information signal by a random code sequence called a PN (Pseudo Noise) code to spread an occupied band for transmission. The reception side multiplies the received spread information signal by the PN code to despread the information signal for reproduction.
The UWB transmission system includes two types: DS-UWB and impulse-UWB. The DS-UWB system maximizes spread speeds of DS information signals. The impulse-UWB system employs an impulse signal sequence having a very short period of approximately several hundreds of picoseconds.
The DS-UWB system can control spectra using PN code speeds, but needs to operate logic circuits with a high speed of the order of GHz, so that undesirably the power consumption easily increases. On the other hand, the impulse-UWB system can be configured in combination with a pulse generator and a low-speed logic circuit, so that there is an advantage of reducing the current consumption. However, disadvantageously, it is difficult to control spectra using the pulse generator.
Both systems can achieve high-speed data transmission by spreading signals to an ultra wide frequency band such as 3 GHz to 10 GHz for transmission and reception. The occupied bandwidth is of the order of GHz, and the occupied bandwidth divided by the center frequency (e.g., 1 GHz-10 GHz) is approximately 1. The occupied bandwidth is ultra wideband compared to bandwidths normally used in wireless LANs based on the W-CDMA or cdma2000 system, and the SS (Spread Spectrum) or OFDM (Orthogonal Frequency Division Multiplexing) system.
Conventionally, there has been used a Gaussian monocycle pulse as an impulse signal for UWB transmission. Let us compare a Gaussian monocycle pulse with a rectangular wave monocycle pulse to examine requirements for the device linearity in pulse generation. An example here uses the rectangular wave monocycle pulse of Tp=200 [ps] and 1 [V]. The Gaussian monocycle pulse follows the equation below. In the equation, constants such as 3.16 and 3.3 are found to provide a spectrum equivalent to the rectangular wave monocycle pulse.
                              x                                                                          (            t            )                          =                  3.16                                t                          T              p                                                      exp                                                              [                                          (                                  3.3                                                        t                                          T                      p                                                                      )                            2                        ]                                              (        1        )
FIG. 23 shows time waveforms. FIG. 24 shows a comparison between frequency characteristics of power spectrum densities for these monocycle pulses. The power spectrum densities [W/Hz=J] in the case where the voltage pulses are transmitted at one pulse per second and are driven under the condition of 50 ohms are shown in FIG. 24.
As can be seen from FIG. 24, a pulse of 100 MHz will yield the power density 80 dB higher than this value. The pulse peak here indicates a power density of approximately −211 dBJ. Consequently, the pulse of 100 MHz yields approximately −131.3 [dBW/Hz=dBJ] just equivalent to the FCC specification of −41.3 [dBm/MHz].
Therefore, the following can be concluded.
(1) The Gaussian monocycle pulse is almost the same as the rectangular wave monocycle pulse in the transmission band. (2) The Gaussian monocycle pulse generates a higher peak voltage than the rectangular wave monocycle pulse, requires the linearity, and makes processing difficult including power amplification.
The conventional UWB communication uses monocycle pulses. FIG. 25 shows the frequency characteristics of power spectrum densities in FIG. 24 in terms of antilogarithms instead of decibels. Though there is no special need for using antilogarithms, the linear representation of energy provides many intuitive benefits.
The spectrum has the following two requirements.
(1) The FCC specifications for spectrum masks disable radiation of 3 GHz or less. (2) The band ranging from 4.9 GHz to 5.3 GHz contains a 5-GHz wireless LAN that should be avoided.
The following can be observed from the linearly displayed power spectrum.
(1) If the above-mentioned requirements are not satisfied, only about half of the power [3 dB] is transmitted. (2) A pulse wave form is expected to be disturbed. The receiving side allows just another half of the energy to pass through a matched filter. (3) There is caused a loss of 6 dB or more in total.
FIG. 26 shows a configuration example (conventional example) of a receiver in the UWB communication system. The configuration of the receiver in FIG. 26 is similar to that of a DS-SS (direct sequence spread spectrum) receiver.
The example in FIG. 26 assumes that the VCO oscillates at the same frequency as the pulse frequency.
The receiver follows the VCO timing and generates a pulse train having data all set to zeros. Using this, the receiver generates three waveforms each deviated for half of pulse width Tp, i.e., Tp/2, and multiplies them by a received signal.
By intentionally deviating the VCO frequency a small amount at the time of detecting a pulse position, a pulse timing match will occur at some point in time (Sliding Correlation).
When a pulse timing match occurs, the energy increases as a result of the multiplication, making it possible to detect the pulse position.
When the pulse position is detected, the intentionally deviated VCO frequency is returned to the correct frequency. At the same time, a tracking operation takes place in order to maintain this timing.
The received signal is multiplied by the waveforms deviated for ±Tp/2 against the center (puncture) to find energies. Differences are used to detect positive and negative values corresponding to positive and negative pulse position errors. These values are supplied to loop filters and are used as control voltages for the pulse position tracking.
However, the receiver configured as shown in FIG. 26 needs to divide a signal path into three and use three multiplication-oriented circuits, thus complicating the circuitry.
Further, the receiver needs to change frequencies for search and tracking operations. The time needed for this changeover prolongs the time for synchronization establishment.
Pulse positions need to be correctly detected under a noise environment. For this purpose, it is necessary to detect that the energy increases more than once. A frequency is intentionally deviated by a slight amount. After the energy increases more than once, resulting values are averaged. Thereafter, pulse positions needed to be detected. Consequently, the time to establish the synchronization becomes lengthy.
Analog circuits are used to configure systems for frequency deviation and tracking. However, analog circuits are often complex and are subject to variance, making it difficult to ensure stable operations.
Energy values are used for the pulse position detection and tracking, thus degrading the S/N ratio and characteristics.
[Patent document 1] PCT Japanese Translation Patent Publication No. 2002-517001
[Non-patent document 1] International Standard ISO/IEC 8802-11:1999 (E) ANSI/IEEE Std 802.11, 1999 Edition, Part11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications
[Non-patent document 2] ETSI Standard ETSI TS 101-761-1V1.3.1 Broadband Radio Access Networks (BRAN); HIPERLAN Type 2; Data Link Control (DLC) Layer; Part1: Basic Data Transport Functions
[Non-patent document 3] ETSI TS 101 761-2 V1.3.1 Broadband Radio Access Networks (BRAN); HIPERLAN Type 2; Data Link Control (DLC) Layer; Part2: Radio Link Control (RLC) sublayer
[Non-patent document 4] NIKKEI ELECTRONICS Mar. 11, 2002, pp. 55-66 "Ultra Wideband: Revolutionary Wireless Technology is Born"
In addition to the above-mentioned related art, there have been proposed by the present assignee a technique related to the present invention as disclosed in U.S. patent application Ser. No. 2004-0179582.

Wireless communication apparatus, wireless communication method, propagation measurement apparatus and propagation measurement method


The present invention relates to a refrigerator. A refrigerator according to the present invention comprises a pair of fixed rails 12 installed on both side walls of inner surfaces of a storage space 11; a pair of movable rails 22 combined with the fixed rails so as to be drawn forward with respect to the fixed rails 12; a food storage container 30 supported on the movable rails 22; a linkage mechanism for moving the storage container 30 upward in a certain range; and a holding means for holding the storage container 30 at a position where the storage container has moved upward by the linkage mechanism. The linkage mechanism includes first and second links 40 and 50, both ends of each of which are pivotably connected to each movable rail 22 and to the storage container 30. According to the refrigerator of the present invention, it is easy to take foods in and out of the storage container of the storage space positioned at a lower position of the refrigerator.

1. Field of Invention
The present invention relates to a refrigerator, and more particularly, to a refrigerator which is configured such that a storage container can be lifted from its lower position to its upper position to allow foods to be easily taken in and out of the storage container for storing the foods therein.
2. Description of the Prior Art
FIG. 1 is shows a cross section of a portion of a refrigerator according to a prior art. Referring to the figure, a storage space 2 formed at an upper portion of the refrigerator is opened and closed by a door 4. A storage container 6 is installed in the storage space 2. The storage container 6 can pivot forward by means of guide levers 9 which are elastically supported to a fixed block 8 in one direction.
Thus, if a user draws the storage container 6 forward in a state where the door 4 positioned at the upper portion is opened, the storage container 6 comes down to a front lower position of the storage space 2 while pivoting about rear ends of the guide levers 9. If the storage container 6 is drawn forward as above, it is shifted from the upper position to the lower position. Thus, it is possible for the user to easily take the foods out of the storage container 6.
According to the prior art, it is easy to take the foods in and out of the storage container 6 by drawing down the storage container 6 in the storage space 2 positioned at the upper portion of the refrigerator.
However, the prior art does not disclose a structure for lifting up another storage container 6 positioned at the lower portion of the storage space 2. That is, in order to take foods in and out of a storage space provided at a lower portion of the refrigerator, the user should fully bend himself/herself forward. To bend himself/herself forward may cause lumbago and make it inconvenient to take foods in and out the storage container.


A user interface for multimedia centers advantageously utilizes hand-held inertial-sensing user input devices to select channels and quickly navigate the dense menus of options. Extensive use of the high resolution and bandwidth of such user input devices is combined with strategies to avoid unintentional inputs and with dense and intuitive interactive graphical displays.

Interactive multimedia centers are characterized by an increasing number of channels of programming available and an increasing amount of functionality offered. The increased number of available channels results from increased program availability from such services as cable and satellites. New types of functionality include recording, time-shifting, and convergence with the Internet. These increases in available programming and functionality result in a dense and complex user interface in an environment that typically does not have a desktop for a mouse or keyboard, the standard input devices for the complex user interfaces typical of personal computers. Rather, the typical user input devices of choice for televisions and multi-media centers is one or more infra-red (IR) remote controls laden with pushbuttons, including arrow, keypad and dedicated function buttons. These button-laden remote controls are utilized for the selection of channels and functions and for onscreen navigation. However, current interactive televisions and multi-media centers now have too many channels and functions for this type of interface to be effective and a more efficient interface is desired.
One bottleneck in this interactive interface is the button-laden remote control. Remote controls typically provide directional arrow buttons for limited incremental on-screen navigation and a baffling array of dedicated buttons for the numerous functions. Pressing the "arrow keys" generally selects the adjacent on-screen element in the direction associated with the arrow. While simple to understand and implement, this step-wise interface is slow and tedious and an impediment to the efficient interaction with the large number of channels and functions in interactive television and multi-media centers.
A second bottleneck is the graphical user interface itself. Program guides, also referred to as "grid guides," are commonly used for displaying available programming. Program guides generally display six to ten horizontal bands, with each band representing channels of available programming. Each horizontal band is broken into segments representing the time when programming changes, which commonly occurs on the hour or half-hour. Users typically scroll and/or page up and down through the available channels in a large loop connected end-to-beginning. Scrolling/paging up generally moves lower in channel number and scrolling/paging down moves higher in the channel listings. Scrolling/paging right in a program guide takes the user ahead in time to scheduled programming and scrolling/paging left goes back in time through the scheduled programming.
Interaction with elements in a program guide is done with the directional arrow buttons on the remote control representing up, down, left, and right. These buttons are generally configured to operate in a step-wise fashion. That is, one click of the button represents one incremental move in the corresponding direction. Also, typical of most program guides are auto-highlighting elements referred to as "Program Cells" within the program guide. As the user steps up and down and back and forth within the program grid, Program Cells are highlighted in sequence, one at a time, indicating the user's interactive position in the display.
As cable, satellite, and internet-delivered programming increases, the small number of programs that fit on a standard program guide display becomes an increasingly smaller percentage of all programs available to the user. Moving through the entire channel lineup and seeing which programs are favorites or what types of programs are available by theme becomes an ever more tedious undertaking. Users may compensate for this in a variety of ways, ranging from memorizing the channel numbers of favorites or remembering how many pages down a desired channel is from another. Providers may attempt to compensate by positioning preferred programs "up front," but at the expense of viewer choice and control. However, neither of these solutions is sufficient and a new type of user interface is required to overcome this problem.
Preferably, such an interface and controller would allow efficient navigation, selection and activation in a dense interface that requires fewer individual buttons on the remote control and allows the user to view the screen rather than the remote control while making selections. Unlike a computer interface, the preferred new interface would not use a mouse, as no desktop is generally available in a television environment, and the interface would not require an on screen cursor.


A sheet conveying apparatus includes: a first conveying unit driven by a first motor; a second conveying unit which is driven by a second motor and situated downstream from the first conveying unit; abnormality detecting unit for detecting an abnormality in the apparatus; a clock unit for counting a predetermined time following the timing of detection of an abnormality by the abnormality detecting unit; and control unit for separately stopping the motors when the abnormality detecting unit has detected an abnormality. The control unit stops the second motor in response to the output from the abnormality detecting unit and stops the first motor a predetermined time there-after in response to the output from the clock unit.

1. Field of the Invention
The present invention relates to a sheet conveying apparatus comprising a plurality of drive motors for conveying sheets. The sheet conveying apparatus is suitable for use in laser beam printers, copying machines, etc.
2. Description of the Related Art
Image forming apparatus, such as a laser beam printer, which performs printing by transferring a toner image formed on the drum to a predetermined area of a recording sheet, generally comprises two motors provided respectively for driving the printing section for continuously forming images and driving the sheet feeding section for supplying sheets to the printing section. These separate motors facilitate efficient print position control including timing control of electrostatic initialization of the printing section, sheet pick-up from the sheet stacker in the sheet feeding section, and re-feeding by the sheet feeding section in accordance with the image forming timing of the printing section. Such print position control can be performed simply by controlling the operations of the individual motors.
However, because the separate drive systems for the sheet feeding section and the printing section have different moments of inertia and cause different drive losses, they require different lengths of time to stop in response to a motor stop signal. In many image forming apparatuses, the printing section, situated downstream of the sheet feeding section, has a larger moment of inertia and therefore requires a longer time to stop than the sheet feeding section. If an emergency stop motor signal is output in such an apparatus due to, for example, sheet jamming, while a sheet is being transferred from the sheet feeding section to the printing section, the sheet is held tense between the two sections. That is because the printing section forcibly pulls the sheet from the sheet feeding section. In such cases, the drive systems, the drum and the like receive excessively large loads, thereby reducing the durability and service life of the apparatus.

Sheet conveying apparatus with stop timing delay of upstream conveying motor


A chemical mechanical polishing (CMP) method utilizes a polishing pad (21) and an under pad (20). The under pad (20) has an edge portion (24) and a central portion (22). The central portion (22) has either a shore D hardness less than a shore D hardness of the portion (24), greater slurry absorption than the edge portion (24), or more compressibility than the edge portion (24). This composite material under pad (20) will improve polishing uniformity of a semiconductor wafer (39). In addition, the use of the polishing pads (20 and 21) allows for greater final wafer profile control than was previously available in the art (FIGS. 4-6).

In the integrated circuit (IC) industry, chemical mechanical polishing (CMP) is being used to polish both metallic and dielectric layers. In order to chemically mechanically polish (CMP) a wafer, a platen/table is provided where a polishing pad is placed on top, of the platen. A chemical slurry is then dispensed on the polishing pad and the polishing pad is rotated. While the polishing pad is spinning, a semiconductor wafer, which is attached to a wafer carrier, is brought in contact with the slurry-covered wafer pad. A chemical and mechanical interaction between the slurry, the polishing pad, and a top surface of the wafer results in material being removed from a top surface of the wafer whereby a planar top surface topography of the wafer is achieved after a certain polishing time period.
A problem confronted by chemical mechanical process engineers is the fact that the polish rate of the center of the semiconductor wafer is much slower or different from the polish rate at the edge of the wafer. These different polishing rates, which are due to lack of uniform slurry transport, rotational speed variations across the radial surface of the wafer, etc., result in the polished surface of the wafer being substantially non-uniform. This non-uniformity CMP problem is clearly illustrated in prior art FIG. 1. FIG. 1 illustrates a semiconductor wafer 10. A top surface of the semiconductor wafer 10 has been polished in FIG. 1. FIG. 1 illustrates a central portion 12 of the wafer 10 and an edge portion 14 of the wafer 10. As can be clearly seen from FIG. 1, the central portion 12 of the wafer 10 has been polished at a much slower rate than the edge portion of the wafer 14 resulting in a thicker central portion of the wafer 10. The difference in wafer-scale material thickness after completion of chemical mechanical polish processing results in reduced yield due to either over-polishing at the edge 14 or under-polishing at the center 12.
The integrated circuit (IC) industry has tried many different methods in an attempt to reduce the non-uniform polishing surface illustrated in FIG. 1. A first method has attempted to make polishing pads that have varying pore densities across a surface of the pad. In one form, a pore density at the edge of the polishing pad is increased when compared to a pore density of the pad near the center of the wafer. This difference in pore density results in the edge of the wafer being exposed to less pad polishing surface while the center of the wafer is exposed to more polishing surface. This difference in polishing surface from the edge 14 to the center 12 may, under certain circumstances, improve chemical mechanical polishing uniformity. However, the changing of the pore density throughout a pad has some disadvantageous effects. First, the changing of the pore density of a chemical mechanical polishing pad does not reduce slurry transport problems associated with CMP non-uniformity. In fact, more pores at the edge may exacerbate this transport problem causing even further non-uniformity than before under certain processing conditions. Therefore, the uniformity improvement resulting from the use of changing pore densities of pads is self-limiting and not overly controllable.
In a second method, the integrated circuit industry has attempted to provide geometric shapes on the surface of a polishing pad to improve slurry transport. For example, geometric grooves have been formed within a top surface of the polishing pad to allow for improved uniformity of slurry transport which aids in polishing uniformity. However, it has been shown that use of grooves on polishing pad surfaces does not eliminate the non-uniformity of the polished surface and is difficult to control in a repeatable manner over pad lifetime.
In addition, the integrated circuit industry has attempted to use overhang polishing in order to render a center polish rate of a wafer and an edge polish rate of a wafer more uniform. Overhang polishing is a process whereby an edge of the wafer is moved off of the edge of a polishing pad so that a portion of the wafer is on the polishing pad while an edge portion of the wafer is not in contact with the polishing pad. In other words, an edge portion of the wafer is periodically not exposed to any polishing surface. By reducing the polish surface area exposed to the edge, the theory is that the edge polish rate will be reduced. Overhang polishing is limited since the overhang of the wafer with respect to the polishing pad can only be slight in order to avoid wafer breakage and serious wafer damage. Therefore, the uniform correcting nature of overhang polishing is inherently limited and typically results in small uniformity improvements that do not entirely eliminate the non-uniformity problem.
The integrated circuit (IC) industry has attempted to apply a backside air pressure to the center of a wafer in order to mechanically bow a wafer such that a polishing rate of a center portion of a wafer is increased with respect to the edge of the wafer. However, the backside air pressure, which is applied to the backside of a wafer, cannot exceed the mechanical pressure applied to the wafer by the wafer carrier. This inherent limitation of the use of backside air is necessary since if backside air pressure increases above the mechanical down pressure of the wafer, the wafer will no longer stay in proper position on the polishing equipment. Therefore, there is inherent limitations in backside air pressure which does not allow the industry to obtain adequate wafer polishing uniformity when backside air pressure is the only uniformity-correcting mechanism used.
Therefore, a need exists for a polishing method and/or a polishing system which will improve the center to edge uniformity of a polished semiconductor wafer and enhance the degree of controllability of the edge-to-center polish rates.

Method of chemical mechanical polishing (CMP) using an underpad with different compression regions and polishing pad therefor