In accordance with the present invention, two types of polymeric dielectric systems useful in construction of a high-temperature electrostatic chuck are disclosed. Further, a high temperature power connection for transmitting power from a supply source to a conductive extension from the electrostatic chuck conductive layer is described. The first polymeric dielectric system provides for the use of polyimide films which do not require an adhesive to adhere to an underlying substrate support platen. The self-adhering polyimide film comprises from one to three layers of polyimide material, wherein at least one outer layer of polyimide material is thermoplastic in nature, for the purpose of adhesion and/or encapsulation. When the film comprises two layers, one of the layers is a non-thermoplastic polyimide having an increased glass transition temperature of about 350.degree. C. or greater. When the film comprises three layers, typically the center layer is the non-thermoplastic polyimide, with the upper and lower layers being a thermoplastic polyimide. The thermoplastic polyimide is placed in contact with a substrate to which it is to bond (such as the surface of a conductive platen used to support a semiconductor workpiece) and heat and pressure are applied to cause the thermoplastic polyimide to flow and bond to the substrate. The second polymeric dielectric system provides for the use of a liquid polyamic acid or modified polyimide precursor which is cured in place against a substrate to provide a polyimide-comprising film adhered to the substrate. Depending on the composition of the polyamic acid or modified polyimide precursor, various degrees of crystallinity can be achieved in the cured, solid polyimide.

1. Field of the Invention
The present invention pertains to an electrostatic chuck used to hold substrates in position during semiconductor processing. The electrostatic chuck is capable of functioning at temperatures greater than 175.degree. C., and preferably greater than 300.degree. C. The electrostatic chuck includes at least one conductive layer positioned between two Polyimide comprising dielectric layers. A specially designed electrical connector capable of operating at the same elevated temperatures is used to supply power from a high DC power source to the conductive layer within the electrostatic chuck.
2. Brief Description of the Background Art
Electrostatic chucks are devices which have gained wide usage in the semiconductor field for clamping semiconductor wafers during manufacturing processes. These chucks eliminate the need for mechanical clamping mechanisms, which are often clumsy and induce contamination into processing chambers. In addition, a clamping mechanism rests on the surface of the substrate and prevents full face utilization of the surface of the substrate. The most popular electrostatic chucks are multilayered structures fabricated using polyimide for the dielectric layers. Polyimide has desirable properties such as high temperature stability (relative to other organic polymers), good dielectric behavior, and excellent mechanical properties. To date, such electrostatic chucks have been used primarily in plasma etching processes, since these processes are carried out at about 130.degree. C. or less. The 130.degree. C. temperature is about the maximum sustainable operational temperature for electrostatic chucks fabricated from conventional polyimides used in combination with non-polyimide adhesive layers. For example, a non-polyimide adhesive layer is frequently used to attach the bottom polyimide of an electrostatic chuck to an underlying metallic pedestal. The underlying pedestal or platen is used to support the semiconductor substrate, to provide heating and cooling of the substrate, and to act as an electrode in many applications.
U.S. Pat. No. 4,645,218 to Ooshio et al., issued Feb. 24, 1987, describes an electrostatic chuck having: an electrostatic attraction body; an electrostatic conductive support body for supporting the electrostatic attraction body; channels for passing cooling medium through the support body; and, a means for covering the exposed surfaces of the support body, except the portion over which the workpiece is placed. The electrostatic attraction body comprises an insulation layer and an adhesive layer which bonds the insulation layer to an underlying platen or pedestal. The insulation layer is a three film composite having a polyimide or polyester upper and bottom dielectric film with an electrode film sandwiched between the upper and bottom dielectric films. The electrostatic chuck is said to be used in a process apparatus such as a dry-etching apparatus, with no reference given as to operational temperatures.
U.S. Pat. No. 4,897,171 to Tadahiro Ohmi, issued Jan. 30, 1990 discloses a wafer susceptor capable of adsorbing a wafer by an electrostatic force and of regulating an electric potential of the wafer to a predetermined value in time. The susceptor comprises a first conductive electrode which includes its flat surface covered with a thin insulating film; a second conductive electrode which is electrically insulated from the first conductive electrode and is disposed so that its surface is flush with the surface of the thin insulating film which covers the first conductive electrode; a means for imparting a specified electric potential to the second conductive electrode; and a means for applying a predetermined voltage between the first conductive electrode and the second conductive electrode.
U.S. Pat. No. 5,221,403 to Nozawa et al., issued Jun. 22, 1993, describes a wafer support table used in a vacuum chamber of a magnetron plasma etching apparatus. The wafer support table includes a member having an electrostatic chuck for supporting the wafer on its upper surface. The electrostatic chuck is constituted of two insulating sheets (polyimide, for example) having an electrically conductive sheet positioned between the insulating sheets. The electrically conductive sheet consists of copper, for example. The maximum operational temperature given is 70.degree. C. to 80.degree. C.
U.S. Pat. No. 5,250,137 to Arami et al., issued Oct. 5, 1993, describes a plasma etching apparatus including an electrostatic chuck constructed of two insulating films having a conductive layer sandwiched therebetween. The conductive layer is said to be made of copper, for example, with the insulating films being made of polyimide, for example. A power supply head is also described which includes a coil spring within an insulating cylindrical body, where the coil spring serves to push upward the power supply head to permit connection of the head to an exposed conductive layer within the electrostatic chuck. No particular temperature of operation is described or claimed.
U.S. Pat. No. 5,275,683 to Arami et al., issued Jan. 4, 1994, discloses a wafer mount useful in a plasma etching apparatus. The mount includes an electrostatic chuck member arranged on top of a susceptor, the electrostatic chuck member having a rim which is curved downward along the curved rim section of the susceptor, departing from the marginal portion of a semiconductor wafer mounted thereon. The electrostatic chuck sheet is said to comprise a pair of polyimide resin films with a thin conductive film such as a copper foil sealed between the polyimide resin films. The films are particularly recommended to be made of a non-crystallized aramid resin having a thickness of about 50 .mu.m, as an alternative to a polyimide resin. The maximum temperature discussed is about 35.degree. C.
U.S. Pat. No. 5,314,573 to Higuchi et al., issued May 24, 1994, describes a dry etching method for anisotropic etching of a semiconductor wafer. The apparatus used comprises an electrostatic chuck having a chuck body constituting the lower electrode, and an electrostatic suction sheet which is flexible and disposed to cover the upper surface of the chuck body. The electrostatic suction sheet included two insulating polyimide sheets and a conductive sheet interposed between the two polyimide sheets. The two polyimide sheets are fused to each other such that the fused portion covers the periphery of the conductive sheet. The maximum operational temperature described for use of the electrostatic chuck is about 130.degree. C.
Although electrostatic chucks using polymeric insulating layers are frequently described for plasma etching at temperatures of 130.degree. C. or less, they have not been described for use at higher temperatures, to the knowledge of applicants. This is due principally to performance limitations of the polymeric adhesives used to attach them to an underlying substrate surface. In any case, it would be highly advantageous to have an electrostatic chuck capable of functioning at temperatures of 200.degree. C. or higher which is fabricated from polymeric insulating layers which tend to be less expensive and offer improved flexibility over ceramics and various oxides which might be used as an alternative.

Electrical connector for power transmission in an electrostatic chuck


The present invention provides a screen suitable for reducing the longitudinal dimension of a set. The present invention includes two prism sections. One is a totally reflective prism section (10) provided at the image generation source side of a Fresnel lens sheet (6). The other is a refractive prism section (11) provided at the image-watching side of the Fresnel lens sheet. The refractive prism section (11) includes a refractive face (e) for refracting incident light and making the light exit toward the image-watching side, a plane (f) approximately parallel to the principal plane of the Fresnel lens sheet, and a connection face (g) for continuously forming the face (e) and the plane (f).

(1) Field of the Invention
The present invention relates to an image display apparatus for enlarging the image generated by an image generation source, and displaying the image in a projection format on a transmissive screen. The invention also relates to the screen and Fresnel lens sheet used for the image display apparatus.
(2) Description of the Related Art
A projection type of image display apparatus (hereinafter, called the set in some cases) projects, in enlarged form onto a transmissive screen via a projection lens and/or the like, the image displayed by the projection cathode-ray tube or liquid-crystal display apparatus (or the like) that functions as a compact image generation source, and thus forms that image on the transmissive screen.
Such a type of set is required to be thinned down (longitudinally downsized) to reduce weight, costs, and an installation space requirement. Known configurations of transmissive screens for use with a thinned-down set include the configuration described in, for example, WO/02/27399 (hereinafter, referred to as Patent Document 1).

Screen, Fresnel lens sheet used for the same, and image display apparatus using the same


A bat or racquet for a new ball catching game has a handle and a head, the head having an orifice through which the ball can pass and also having a net-like material against which the caught ball strikes. The net-like material is attached to a pair of opposed elements which are slidable in a frame inside the bat. The opposed elements are spring-loaded with the springs being arranged to be off-centre for the elements to snap between a first ball-receiving condition, and a second ball-capturing condition.

1. Field of the Invention
This invention relates to a bat for a catching game.
2. Description of the Related Art
There are many games which involve the catching of a ball with a bat, racquet or the like and the ball is then thrown from the bat. Such games include pelota and lacrosse.
Beach tennis bats are also known, but it is an object of the present invention to provide a new game which can be played anywhere and which gives young and old excellent enjoyment and exercise.


A boat trailer has an extendible tongue and includes a trailer body along with a tongue having a hitch attachment on one end thereof for removably attaching the tongue to a vehicle. A telescoping tongue is fixedly attached to the boat trailer body and has a pair of roller brackets attached thereto for telescoping the tongue. Each roller bracket is movably attached to the tongue for rolling engagement therewith. A latching mechanism is attached to the tongue for removably locking the tongue to one of the roller brackets on the telescoping tongue to thereby latch the tongue to the telescoping tongue to prevent the telescoping tongue and trailer body from moving relative to the tongue when in a latched position and to allow the telescoping tongue and trailer body to telescope relative to the tongue when the latching mechanism is unlatched from the roller bracket. The latching mechanism has a spring loaded latching arm having a catch for engaging and locking dog on one bracket and has a lever release arm coupled to the latching arm to release the latch arm from the dog to thereby allow the telescoping tongue to telescope relative to the tongue.

The present invention relates to a boat trailer and especially to a boat trailer having an extending tongue mechanism for use in launching or loading a boat onto the boat trailer.
As any boat enthusiast knows who trails his boat to a ramp or shore for launching, there are severe limitations to the conventional boat trailers which prevent the enthusiast from launching or retrieving his boat in shallow water or at low tide or in the event that his boat has a deep keel, such as, for example, in the case of sailboats which are provided with relatively deep fixed keels. While these adverse conditions are not always present when the boater wishes to enjoy the pleasures afforded by boating or sailing, they nevertheless may limit his full use of his or her boat.
There have been attempts in the prior art to minimize the loss of full use of boats for the operator by arranging boat trailer tongues with extension devices which permit the operator to elongate the tongue so that the vehicle towing the trailer need not drive his vehicle too close to or into the water's edge, and yet be able to move the trailer further out into the water thereby avoiding inadvertent scraping of the bottom of the launch site by his boat keel.
Another disadvantage with some of the conventional tongue and extension mechanisms is that these extensions are integrated into and are a part of the tongue itself, and thereby become too expensive for the average boater. These arrangements require that those boaters who presently own and operate conventional boat trailers must discard their boat trailer and purchase a new one in the event that they need the same only occasionally. In any event, the trailers of the prior art require an expensive apparatus that is not necessarily utilized for all boating opportunities.
Prior art boat trailer structures include an extension device in U.S. Pat. No. 4,169,611 to Smith et al. which is a dedicated piece of structure which is integrally incorporated into the boat trailer tongue. The same disadvantage is also generally found with the trailer hitch arrangement disclosed in U.S. Pat. No. 3,326,573 to Neitzey, Jr.
Examples of other telescoping trailers may be seen in the U.S. patents to Englehardt et al., U.S. Pat. No. 2,944,835; and to Neitzey, Jr., U.S. Pat. No. 3,326,573; and in the prior art patent to Kelley, U.S. Pat. No. 3,142,494; and in the patents to Lusk, U.S. Pat. No. 3,738,684; and Williams, et al., U.S. Pat. No. 3,032,353; and Moody, et al., U.S. Pat. No. 3,083,986; and Thurman, U.S. Pat. No. 3,428,336; and Walters, U.S. Pat. No. 4,331,346; and Sprague, U.S. Pat. No. 4,623,161; and Pierce, U.S. Pat. No. 4,232,990; and Foster, U.S. Pat. No. 3,989,266; and Grice, U.S. Pat. No. 5,011,177.
The present invention distinguishes from these prior patents by being a boat trailer having an extending tongue which is easily added to or adapted to an existing boat trailer which simplifies the locking and unlocking of the telescoping arm which telescopes on roller brackets having two boat tongues, one extending relative to the other in parallel fashion.


The present invention provides an apoptosis inducer and a therapeutic agent for eosinophilic diseases which comprises, as an active ingredient, an antibody which reacts specifically with eosinophils and induces apoptosis of eosinophils; and a method for inducing eosinophil apoptosis using the antibody, and a method for specifically reducing or removing eosinophils in peripheral blood or tissues using the antibody.

Eosinophils are implicated in various diseases including allergic diseases, and are thought to play an important role in generating morbidity of allergic diseases such as chronic bronchial asthma and atopic dermatitis [Adv. Immunol., 39, 177(1986), Immunol. Today, 13, 501(1992)].
In addition to the above diseases, eosinophils are also implicated in diseases generally referred to as hypereosinophilic syndrome (HES), such as eosinophilia, eosinophilic enterogastritis, eosinophilic leukemia, eosinophilic granuloma and Kimura's disease [Ann. Intern. Med., 97, 78 (1982)].
Eosinophilic granuloma is nonneoplastic cryptogenic lesion, which is an osteolytic and focal, and is known to be associated with remarkable tissue cosinophulia [U.S. Armed Forces Med. J., 2, 1085 (1951)]. According to the registry of bone tumor patients in Japan (1972-1984), 379 out of 404 bone tumor patients (93.8%) suffered from eosinophilic granuloma. Hence, in addition to inflammatory diseases, such as allergy, eosinophils can cause other various diseases.
Interleukin-5 (hereinafter referred to as IL-5), interleukin-3 (hereinafter referred to as IL-3) and granulocyte-macrophage colony-stimulating factor (hereinafter referred to as GM-CSF), which are members of cytokine family, are involved in regulating the differentiation, proliferation and activation of eosinophils. Of these cytokines, IL-5 is known to act specifically on eosinophils and specifically induce the terminal differentiation [Proc. Natl. Acad. Sci. U.S.A., 85, 2288 (1988)].
An anti-IL-5 antibody has been developed as an anti-inflammatory agent. A humanized anti-IL-5 antibody, SB-240563 (Smithkline Beecham), is effective in reducing the number of eosinophils in peripheral blood of mild asthma patients (100th Annual Meetings of the American Society for Clinical Pharmacology and Therapeutics, March/1999). Moreover, a humanized anti-IL-5 antibody, Sch-55700 (CDP-835) (Scherring-Plough/Celltech) is known to inhibit lung eosinophilia induced by antigens in allergic monkey models [Arzneimittel-Forschung, 49, 779 (1999)].
In vitro, IL-3 and/or GM-CSF can activate eosinophils or prolong their survival [J. Clin. Invest., 81, 1986 (1988)]. Further, IL-3 and/or GM-CSF acts also predominantly on the induction of immature eosinophils from myeloid stem cells [Blood, 76, 1956 (1990)]. Furthermore, chemokines such as eotaxin and RANTES (regulated on activation normal T-cell expressed and secreted), induce the chemotaxis of eosinophils to inflamed site [Clin. Exp. Allergy, 26, 1005 (1996)]. Stem cell factors (hereinafter referred to as SCF) are involved in the accumulation of eosinophils to lung in allergic bronchitis. In addition to IL-5, there are many factors affecting function of eosinophils.
Eosinophils are divided into subgroups, normodense eosinophils and hypodense eosinophils. Eosinophils have been shown to be hypodense eosinophils upon activation [Immunology, 47, 531 (1982)]. Hypodense eosinophils are also referred to as activated eosinophils. It has been reported that a qualitative change occurs in addition to a quantitative change in eosinophils in the peripheral blood of an HES patients [Clin. Exp. Immunol., 24, 423 (1976)]. Activated eosinophils have been implicated in the severity of HES symptom [Am. J. Cardiol., 52, 321 (1983)]. Aside from HES patients, activated eosinophils have been also found in the peripheral blood, and in bronchoalveolar lavage fluid (BALF) of a patient with bronchial asthma [Am. Rev. Respir. Dis, 132, 981 (1985)]. Various receptors, such as those of cytokines, are expressed on activated eosinophils (hypodense eosinophils) [J. Immunol., 142, 4416 (1989)]. Compared to normodense eosinophils, these hypodense eosinophils show elevated sensitivities against IL-5 [Clin. Exp. Immunol., 85, 312 (1991); J. Exp. Med., 172, 1347 (1990)].
The above-mentioned activated eosinophils are also known to survive in vitro without the cytokines inducing in the differentiation and proliferation of eosinophils [J. Exp. Med., 170, 343(1989)]. Thus, the properties of activated eosinophils are similar to those of eosinophils which infiltrate tissues, such as alveoli [Int. Arch. Allergy Immunol., 120, 91 (1999)]. A detailed explanation of why activated eosinophils become cytokine-independent remains unknown, however, their degranulation and prolonged survival are likely to be induced by various vital functional molecules other than IL-5.
Substances having inhibition activity on cytokines or chemokines that are involved in the differentiation or proliferation of eosinophils have been considered as agents that inhibit the eosinophil functions. However, in most cases these agents do not act on cytokine-independent eosinophils that have been activated and infiltrated into inflamed areas. Hence, eosinophil-specific inhibition and the induction of cellular death of activated eosinophils are necessary to inhibit the functions of any eosinophil.
However, no anti-inflammatory agent, so far, has been known to induce apoptosis of activated eosinophils.
Current major treatment for patients with eosinophilic diseases consists of administration with steroid. However, steroid administration is often associated with side effects. Specifically, the treatment has some other problems, such that patient's pathological condition may return to the original state when steroid administration is discontinued, and prolonged steroid administration may induce steroid resistance. As for now, it is difficult to inhibit the eosinophilia and there exists no way other than the symptomatic treatment thereof.

Methods using eosinophil-specific apoptosis inducer


A method for administering clinical trial material includes a method for administering clinical trial material, comprising the steps of providing at least one kit containing a plurality of bottles, each with two separate indicia appearing thereon, at least one of the bottles containing a quantity of clinical material at a first dosage, and another at least one of the bottles containing one of a quantity of the clinical material at a second dosage, a quantity of control drug and a placebo; identifying first and second study groups, each providing a treatment schedule for administering dosages of at least one of the clinical material, the control drug and the placebo, the first and second study groups having different treatment schedules; randomly assigning patients to the first and second study groups; assigning at least one investigator to administer the contents of the plurality of bottles; telephone means accessible to the investigator and having a keypad; providing sponsor computer means including telephony capabilities and for storing information, disseminating information, and instructions over the telephone to the investigators, and for receiving information and instructions over the telephone from the investigators, the computer means operable, upon being contacted by the investigator, to identify which of the plurality of bottle of the kit is to be disseminated to an identified patient, but requiring the investigator to confirm selection of the correct bottle by requesting the investigator to enter into the telephone keypad one of the identifying indicia appearing on the selected bottle; and distributing the at least one kit to said investigator.

Clinical trials of new drugs provide critical data on the drug's effectiveness, dosage requirements and possible adverse side effects. Unlike marketing strategies developed and applied to the introduction and sales of a new drug, it is desired and sometimes necessary in clinical studies to conceal or "blind" the drug to be studied. Blinding the clinical study is believed necessary to prevent bias from the participants--patients, investigators and sponsors--from comprising the results. Blinded studies can also enhance marketability of a product by more credibly demonstrating the favorable health and economic advantages, such as greater therapeutic efficacy and fewer adverse effects, when compared with a marketed drug or placebo. In addition, many governments require blinded clinical studies for approval of a new drug. (See 21 C.F.R. 314.26 and European Union's Directive 91/507/EEC).
Common types of blinding used in clinical studies are outlined in Table 1:

Method for administering clinical trail material


The invention relates in general to a cutting and clamping sleeve contact for contacting a cable core transversely to the sleeve axis, and in particular for cable cores of the telecommunication technology. The contact is made of a metal sleeve shell and includes a clamping slot for the insulated cable core and a cutting and clamping contact slot within the sleeve for the stripless termination of the cable core. The present invention also relates to a method for producing the cutting and clamping sleeve contact. A portion 13 of a sleeve shell 12 is bent off radially into an interior of the sleeve body 12 and is provided with a cutting/clamping contact slot 2. A clamping slot 3 is opposite to the cutting/clamping contact slot 2 and is cut into the sleeve shell 15. The present invention improves the cutting and clamping sleeve contact, with regard to the independence of the cutting/clamping slot 2 from the movements at the clamping slot 3, and with regard to the observation of accurate tolerances.

A similar cutting and clamping sleeve contact of the aforementioned species is known from the German Patent DE 37 09 376 C1. In this document, shell portions are cut free from the metal sleeve shell and are bent off towards the interior of the sleeve as contact legs, so as to form the cutting and clamping contact slot. The clamping slot for holding the insulated cable core is formed by the end edges of the round, oval or polygonal sleeve body being disposed in a small distance. It is disadvantageous, herein, that widening of the clamping slot for the insulated cable core will also cause widening of the cutting and clamping contact slot for the stripless termination of the cable core. This happens in particular, when the contact legs, which are bent off towards the interior of the sleeve and form the cutting and clamping contact slot, are bent from an area adjacent the clamping slot and towards an interior. This further happens when the cable cores having a relatively thick insulating sheath and a small core diameter are terminated at the sleeve contact. The thick insulating sheath widens the clamping slot, resulting in corresponding widening of the cutting and clamping contact slot which may then not be capable to contact the thin wire anymore.
Further, it has been shown that the prior art cutting and clamping sleeve contact exhibited relatively large tolerances of the slot widths from one sleeve contact to other when bending the contact legs together for forming the slot width of the cutting and clamping sleeve contact. Thus, production of the contact slot is practically impossible with acceptable tolerances.


A computer system is operable to identify subfields that differ in two data elements using a bit matrix compare function between a first matrix filled with pattern elements and a reference pattern.

Most general purpose computer systems are built around a general-purpose processor, which is typically an integrated circuit operable to perform a wide variety of operations useful for executing a wide variety of software. The processor is able to perform a fixed set of instructions, which collectively are known as the instruction set for the processor. A typical instruction set includes a variety of types of instructions, including arithmetic, logic, and data movement instructions.
Arithmetic instructions include common math functions such as add and multiply. Logic instructions include logical operators such as AND, NOT, and invert, and are used to perform logical operations on data. Data movement instructions include instructions such as load, store, and move, which are used to handle data within the processor.
Data movement instructions can be used to load data into registers from memory, to move data from registers back to memory, and to perform other data management functions. Data loaded into the processor from memory is stored in registers, which are small pieces of memory typically capable of holding only a single word of data. Arithmetic and logical instructions operate on the data stored in the registers, such as adding the data in one register to the data in another register, and storing the result in one of the two registers or in a third register.
Oftentimes comparison of data will require comparison of multiple subfields of data. This typically entails execution of numerous instructions per field.

Inclusive or bit matrix to compare multiple corresponding subfields


Transport and in-space assembly of spacecraft from not-qualified-for-launch, low cost parts/modules. Any number of spacecraft or parts thereof are built inexpensively for space usage when they are transported in a manner that does not subject them to stresses of the launch environment. Such spacecraft/parts are transported whole, or in component pieces, in protective containment, i.e., qualified containers which meet all of the applicable safety and performance requirements for containers launched into space. These whole or component pieces of spacecraft may then be tested and deployed and/or assembled and deployed by either robot or human activity. The spacecraft, when at times modular, are assembled so as to form larger structures in space. This piecewise method of construction provides a significant increase in cost-effectiveness concerning both radical spacecraft design and spacecraft-to-launch vehicle qualification processes.

Not Applicable
Not Applicable
1. Field of the Invention
This invention relates, in general, to spacecraft and their assembly, transport to and placement in exospheric environment. In particular, it involves a radical departure from the current state of the art in that it forgoes the modern practice of designing and building orbital and interplanetary craft, regardless of their required degree of structural strength, to the standards necessary to survive the rigors of rocket launch shocks, vibrations and g-forces. This departure from the current practice consists in special containerization of spacecraft components or modules, conventional rocket transport of the components/modules to an orbital assembly locus, and final in-orbit assembly and deployment by human or robotic effort.
2. Description of Related Art
The designer of spacecraft, particularly those bearing delicate devices such as scientific instrumentation, has been confronted with serious difficulties in designing mechanical and electrical articles/ devices that must survive a severe transport environment of shock, vibration, acoustical coupling, decompression and thermal variation. Today, spacecraft are flown on launch vehicles of the United States Space Transportation System (STS) as well as vehicles from China, Russia, Israel and the European Union. Common to all of these vehicles, under the best of circumstances, is the requirement that any spacecraft, or other payload that flies on them, be designed to survive acceleration, vibration, and acoustic forces that are several times those they will experience in space. These design requirements literally drive the cost and scheduling of a spacecraft mission and thereby define a problem well known in the field, that of acquiring spacecraft rocket launch-survivability at high cost and heavier than (technically) necessary construction.
U.S. Pat. No. 5,271,582 shows a spacecraft constructed of multiple payloads (modules) and which is rocket-launched and placed in earth orbit as a unitary article. To place this craft in space by a conventional launch vehicle, it must be constructed to standards such as NASA STD 5003, which will ensure its survival in the launch and space environments. Such standards, when met by a system or component/sub-system, including special containers or packaging, acquire a launch/ rocket-transport/space qualification, i.e., are certified and termed xe2x80x9cqualifiedxe2x80x9d.
In the present practice, whole satellites/spacecraft must be qualified for acceptance aboard, and launched by conventional launch vehicles. The aforesaid requirement for qualification, therefore, militates the high cost design and construction of all satellites/spacecraft.
The deficiencies and limitations of prior art and practice, in the launching and space posturing of space systems, craft or satellites (hereinafter, xe2x80x9ccraftxe2x80x9d), are overcome by my method. First, a desired craft is designed as an ensemble of modular sub-systems/ components/ devices that may be readily assembled by human and/or robot effort, cognizant of the fact that the modules need not be fabricated to xe2x80x9cqualifiedxe2x80x9d standards, but only to those necessary to perform their intended functions, in their intended environments. For example (and as will be further delineated hereafter), craft are in fabrication that utilize this modular concept and whose structures are made from sheet or formed aluminum rather than costly machined aluminum and expensive composites. Their average structural design costs plunge as much as 90%; so also may the costs associated with deployable booms, antennas, or other appendages. A concurrent advantage of using the instant transporting method is elimination of the second and third most common failures plaguing spacecraft today-separation failure and malfunction in deploying appendages in space. Another asset is the ability to test spacecraft and replace failing modules/ components before final deployment.
In preparation for launch, an assembled craft, or an assemblage of components (module) of a craft is placed within a container that is itself qualified, without the (contained) craft/assemblage being so qualified. Thus, the craft or assemblages that can be put together (be built into a craft) by robot or human methods are materially less expensive than those built in current practice.
The individual pieces, parts, system or subsystem parts that are carried aloft in the manner described are assembled, say as modular parts, into an operating spacecraft that can be deployed into orbit or remain a fixed part of the space station. The spacecraft will be made of fit-together subassemblies (components or modules) that can be assembled into an operating satellite, or used to construct larger space vehicles. The spacecraft will have, but are not limited to, batteries, solar arrays, attitude control devices, structural and propulsion elements, and science, engineering, or commercial payloads.
After launch and space positioning are accomplished, a craft is built in space or in orbiting facilities best exemplified by the U.S. Space Shuttle or the International Space Station (ISS). The craft would then be deployed from the orbiting facility, to proceed on the mission for which it was designed.

Transportation of unqualified spacecraft or component to space


A method for forming an anti-reflective coating (ARC) layer within a fabrication and a fabrication having the anti-reflective coating (ARC) layer formed therein. To practice the method, there is first provided a substrate. There is then formed over the substrate a reflective layer. There is then formed upon the reflective layer an organic polymer anti-reflective coating (ARC) layer, where the organic polymer anti-reflective coating (ARC) layer is formed from an organic polymer anti-reflective coating (ARC) material which is not susceptible to a hydrolysis reaction. There may then be formed upon the organic polymer anti-reflective coating (ARC) layer a photoresist layer which is photoexposed and developed to form a patterned photoresist layer which may be employed as an etch mask for forming a patterned reflective layer from the reflective layer. The patterned reflective layer so formed is formed with uniform and reproducible linewidth dimension.

1. Field of the Invention
The present invention relates generally to anti-reflective coating (ARC) layers employed within fabrications having reflective layers formed therein. More particularly, the present invention relates to organic polymer anti-reflective coating (ARC) layers employed within fabrications having reflective layers formed therein.
2. Description of the Related Art
Microelectronics fabrications are formed from microelectronics substrates over which are formed patterned microelectronics conductor layers which are separated by microelectronics dielectric layers.
In the process of forming patterned microelectronics conductor layers within microelectronics fabrications, as well as forming other patterned reflective layers within microelectronics fabrications, it is common in the art of microelectronics fabrication to employ an anti-reflective coating (ARC) layer formed interposed between: (1) a blanket reflective layer from which is formed the patterned reflective layer, such as the patterned conductor layer; and (2) a blanket photoresist layer from which is subsequently formed a patterned photoresist layer which is employed to define the patterned reflective layer, such as the patterned conductor layer. Such blanket anti-reflective coating (ARC) layers are desirable within microelectronics fabrications since they attenuate standing wave reflections from the blanket reflective layer when photoexposing the blanket photoresist layer, which standing wave reflections would otherwise lead to inhomogeneous photoexposures of the blanket photoresist layer and an attendant compromise of the patterned photoresist layer linewidth uniformity and reproducibility, which in turn leads to a correlating compromise of the patterned reflective layer linewidth uniformity and reproducibility.
Although blanket anti-reflective coating (ARC) layers may be formed within microelectronics fabrications from any of several anti-reflective coating (ARC) materials, such as but not limited to inorganic thin film anti-reflective coating (ARC) materials and organic polymer anti-reflective coating (ARC) materials, organic polymer anti-reflective coating (ARC) materials are often preferred when forming anti-reflective coating (ARC) layers within microelectronics fabrications since organic polymer anti-reflective coating (ARC) materials may be coated onto reflective layers within microelectronics fabrications through use of methods analogous or equivalent to methods employed in forming blanket photoresist layers upon those blanket organic polymer anti-reflective coating (ARC) layers within those microelectronics fabrications.
While anti-reflective coating (ARC) layers formed from organic polymer anti-reflective coating (ARC) materials are thus desirable within the art of microelectronics fabrication, anti-reflective coating (ARC) layers formed from organic polymer anti-reflective coating materials are not formed entirely without problems within microelectronics fabrications.
In particular, it is known in the art of microelectronics fabrication that anti-reflective coating (ARC) layers when formed from polyimide organic polymer anti-reflective coating (ARC) material compositions incorporating dyes, additives and solvents as are appropriate to specific microelectronics fabrications often suffer from problems including but not limited to: (1) void formation, such as pinhole void formation, within the polyimide organic polymer anti-reflective coating (ARC) layers; and (2) delamination of the polyimide organic polymer anti-reflective coating (ARC) layers from blanket reflective layers or blanket photoresist layers interposed between which the organic polymer anti-reflective coating (ARC) layers are formed. Problems such as void formation within polyimide organic polymer anti-reflective coating (ARC) layers within microelectronics fabrication and delamination of polyimide organic polymer anti-reflective coating (ARC) layers from adjoining layers within microelectronics fabrications are undesirable within the art of microelectronics fabrication since such problems often contribute to difficulties in ultimately forming patterned reflective layers of uniform and reproducible linewidth within microelectronics fabrications.
It is thus towards the goal of forming organic polymer anti-reflective coating (ARC) layers within microelectronics fabrications with attenuated void formation within those organic polymer anti-reflective coating (ARC) layers and with attenuated delamination of those organic polymer anti-reflective coating (ARC) layers from adjoining layers within the microelectronics fabrications within which are formed those organic polymer anti-reflective coating (ARC) layers that the present invention is directed.
Various polyimide organic polymers materials, polyimide organic polymer material compositions and uses thereof, have been disclosed in the art of microelectronics fabrication.
For example, Mueller et al., in U.S. Pat. No. 4,927,736, discloses a series of hydroxy polyimide organic polymer materials and a series of high temperature positive photoresist compositions which may be formed from the series of hydroxy polyimide organic polymer materials. The hydroxy polyimide organic polymer materials may be synthesized by condensation of an appropriate hydroxy substituted aminophenol with an appropriate dianhydride to form a hydroxy polyimide organic polymer material which may be incorporated into a high temperature positive photoresist composition from which may be formed a high temperature positive photoresist layer which in turn may be developed with an aqueous base developer.
In addition, Maeda et al., in U.S. Pat. No. 5,320,935, discloses a method for forming a series of poly(amide)imide precursor polymer materials having pendant hydroxyphenyl groups, where the poly(amide)imide precursor polymer materials may be employed within high temperature photoresist compositions. The high temperature photoresist compositions in turn exhibit excellent shelf stability and good photosensitivity.
Finally, Katou et al., in U.S. Pat. No. 5,342,739, which is related to and co-assigned with U.S. Pat. No. 5,320,935, disclose a method for forming a negative photoresist pattern employing a negative photoresist composition formed in part from the poly(amide)imide precursor polymer materials disclosed within U.S. Pat. No. 5,342,739. The negative photoresist composition additionally employs a quinonediazide in conjunction with a poly(amide)imide precursor polymer material to form the negative photoresist composition having the excellent shelf stability and the good photosensitivity.
Desirable in the art of microelectronics fabrication are methods and materials through which there may be formed organic polymer anti-reflective coating (ARC) layers within microelectronics fabrications, where the organic polymer anti-reflective coating (ARC) layers when formed within the microelectronics fabrications have: (1) attenuated pinhole formation within the organic polymer anti-reflective coating (ARC) layers; and (2) attenuated delamination of the organic polymer anti-reflective coating (ARC) layers from layers adjoining the organic polymer anti-reflective coating (ARC) layers. It is towards the foregoing goals that the present invention is directed.

Hydrolytically stable organic polymer material for organic polymer anti-reflective (ARC) layer

Chartered Semiconductor Manufacturing Ltd.


Stepper motor winding current regulation methods and apparatus continuously and bi-directionally sense winding current to determine both the magnitude of the winding current and the slope of a waveform representing the winding current. The magnitude and slope information is used to more precisely control periods of current rise and characteristics of fast and slow current decay during pulse-width modulation (“PWM”) regulation cycles. Winding current rise and decay shaping is based upon the sensed magnitude of the winding current, the magnitude of the winding current regulation set-point ITRIP, whether the sensed winding current is greater than or less than ITRIP at a selected sampling time, whether the sensed winding current is increasing or decreasing when a waveform of the sensed winding current crosses over ITRIP, and whether or not the magnitude of ITRIP changes during a PWM cycle in response to a receipt of a subsequent DAC code.

In stepper motors, motor position is controlled by regulating electrical current in each motor winding. Different stepper motor designs may have different numbers of windings, with the current waveform in each winding leading or lagging current waveforms associated with the other windings. For purposes of this disclosure, current regulation in a single winding is referred to as an example of the current regulation in each winding.
The current waveform in a given motor winding is, in many modern implementations, shaped by an output of a digital-to-analog converter (DAC). As is well-known in the art, a DAC output waveform, when viewed with sufficient magnification, is formed in a stair-stepped shape. For each digital input code ("DAC code"), an ideal DAC maintains a corresponding analog output voltage level. For example, a series of adjacent input codes (e.g., 00000000, 00000001, 00000010, and 00000011 in the case of binary input codes) applied sequentially at a DAC input results in a stair-stepped output waveform shape with each step up of equivalent magnitude to the previous step up.
In the case of a stepper motor, each DAC input code results in a different mechanical rotational position of the stepper motor rotor. As such, any particular section of the waveform is stair-stepped upward for increasing currents and stair-stepped downward for decreasing currents. Micro-stepping resolution, the number of steps in an electrical 360 degree revolution, is limited by the accuracy with which each motor winding current level can be regulated during the constant current portion of each step. That is, once a DAC input code is applied and the winding current reaches a level corresponding to the top of the DAC step up or to the bottom of the DAC step down, that level of winding current is regulated to avoid any further mechanical rotation or vibration of the rotor until a different DAC input code is applied. Absent such regulation, factors such as supply voltage variations and changes in mechanical loads on the stepper motor may cause winding current to vary during the duration of the desired step.
Like many methods of electrical voltage and current regulation, stepper motor winding current regulation may be hysteresis-based. That is, the regulation method may allow the winding current to ramp up to a set-point level corresponding to an applied DAC code. The set-point level of winding current is referred to herein as "ITRIP." When a forward voltage is applied across the winding, winding current ramps up during a period referred to herein as the "t_ON" period. When the winding current reaches ITRIP, the regulation mechanism then either disallows active drive to the winding or reverses voltage polarity across the winding during a period referred to herein as the "t_OFF" period. During a first portion or all of the t_OFF period referred to herein as the "decay" period, the winding current ramps down toward zero. If the negatively-sloped winding current reaches zero, the regulation mechanism may maintain the winding current at zero for the duration of the t_OFF period until allowing another ramp up to ITRIP. The sum of the t_ON period and the t_OFF period is referred to herein as a PWM cycle.
It is noted that multiple PWM cycles may occur over the duration of any step associated with a given DAC input code. For example, a stepper motor controlling vertical paper positioning in an inkjet printer may move to a particular position and remain at that position for hundreds of milliseconds while the inkjet head moves across the sheet of paper horizontally or even for several seconds to allow ink to dry on the sheet of paper before ejecting the sheet. Several or many PWM current regulation cycles may occur during these periods while the same DAC input code is applied to or latched into the vertical positioning stepper motor to create a corresponding DAC analog output level.
The slope of the decay waveform associated with the t_OFF period is important in the overall scheme of regulating the stepper motor current for the duration of a given step. The inability of conventional decay modes to precisely regulate average current level and ripple in the windings at a particular step may significantly limit micro-stepping resolution for a given stepper motor configuration.
FIG. 1 is a prior-art schematic diagram of a typical "H-bridge" switching apparatus 100 used to regulate stepper motor current. Four switches S1-S4 are sequenced by current regulation logic (not shown) to control current through the winding 110. The current paths 115, 120, and 125 and corresponding directions are indicated by the dashed lines. Feedback to the current regulation logic is provided by a voltage drop across a sense resistor 130 corresponding to current flowing along the paths 115 and 120.
FIG. 2 is a series of prior-art waveform diagrams illustrating various modes of operation of the H-bridge 100 associated with known methods of stepper motor current regulation. Considering now FIG. 2 in light of FIG. 1, the regulation logic turns switches S1 and S2 to a conductive state to ramp up current along the path 115 and through the winding 110 during the t_ON period 215 as shown in the three graphs of FIG. 2. Feedback from the sense resistor 130 may be ignored by the regulation logic during a blanking period tBLANK in order to avoid erratic feedback caused by abrupt current changes in the winding 110 at the start of t_ON.
The three graphs of FIG. 2 illustrate three different decay modes implemented by various prior-art current regulation logic circuits in conjunction with the H-bridge 100. Each decay mode controls the rate of decay of the current waveform through the stepper motor winding. The motor winding current decay rate is controlled in an effort to control jitter in the overall current waveform, particularly at waveform peaks where the slope of the current waveform changes direction and at zero cross-over points where the waveform changes polarity.
The decay portion 220 of the slow decay waveform 222 corresponds to the current path 125 of FIG. 1, implemented by enabling switches S2 and S3 to a conductive state and disabling switches S1 and S4 of the H-bridge 100. Disabling switches S1 and S4 prevents motor drive voltage VM from being applied across the motor winding 110. Enabling switches S2 and S3 allows the slow decay current waveform 220 to slowly dissipate through internal resistance associated with the current path 125. A potential problem exists with slow decay mode, particularly for smaller regulated currents. Energy stored in the inductance of the motor winding 110 may not dissipate completely and take the slow decay current waveform 220 to a sufficiently low level by the end of the t_OFF period and prior to the start of the next PWM cycle. This problem may impose a lower limit on the magnitude of current that may be finely regulated and thus on the driver DAC step size and resolution.
The decay portion 230 of the fast decay waveform 232 corresponds to the current path 120 of FIG. 1, implemented by enabling switches S3 and S4 to a conductive state and disabling switches S1 and S2 of the H-bridge 100. The latter configuration of switches reverses the polarity of voltage applied across the motor winding 110, causing the decay portion 230 of the fast decay current waveform 232 to rapidly decrease to zero. A potential problem with fast decay mode is that the discharge rate of the motor winding 110 during the decay period associated with the decay waveform 230 is approximately equal to the charge rate associated with the t_ON period 215. This may result in choppy regulation reflected as excessive ripple in the overall current waveform, particularly at waveform peaks where the DAC step period is large relative to the DAC step magnitude. The latter problem may impose a limitation on the DAC step size and resolution as the step size becomes low relative to the magnitude of the ripple.
A fixed mixed-mode of decay 240 is known. Fixed mixed-mode is implemented by initially configuring the switches S1-S4 of the H-bridge 100 as described above for fast decay mode 232 to create a period of fast decay t_FAST 250 corresponding to decay waveform portion 255. The H-bridge 100 is then switched to the configuration described above for slow decay mode 222 to create a period of slow decay t_SLOW 260 corresponding to the decay waveform portion 265. One problem with fixed mixed decay mode is that the periods 250 and 260 associated with the fast and slow decay periods, respectively, typically result from a compromise for a given motor and supply voltage. Also, a particular ratio of fixed periods 250 and 260 may be better suited to some current levels and waveform slopes than to others.

Dynamic mixed-mode current decay apparatus and methods


A polyurethane composition containing solid beads dispersed therein, is formed of a microcellular polyurethane foam, and the composition has a storage modulus of elasticity at 40° C. of 270 MPa or more as measured by means of a dynamic elasticity measuring device. Another polyurethane composition of this invention contains solid beads dispersed therein, that are capable of swelling with or are soluble in an aqueous medium. The former composition has excellent flattening capability, and the latter composition can provide a polished surface which combines good flatness and good uniformity and can also reduce scratches on the surface.

Typical materials requiring surface flatness at high level include a single-crystal silicon disk called a silicon wafer for producing semiconductor integrated circuits (IC, LSI). The surface of the silicon wafer should be flattened highly accurately in a process of producing IC. LSI etc., in order to provide reliable semiconductor connections for various coatings used in manufacturing the circuits. In the step of polishing finish, a polishing pad is generally stuck on a rotatable supporting disk called a platen, while a workpiece such as a semiconductor wafer is stuck on a polishing head. By movement of the two, a relative speed is generated between the platen and the polishing head while polishing slurry having abrasive grains is continuously supplied to the polishing pad, to effect polishing processing.
As the polishing pad, foamed polyurethane or the like having a pore structure having a function capable of retaining supplied slurry is used. However, such foamed polyurethane is poor in surface hardness. A polishing pad having hollow fine spheres entrapping high-pressure gas or water-soluble polymer powder dispersed in matrix resin such as polyurethane, as described in Japanese Patent No. 3013105 and JP-A 2000-71168, has been proposed as the polishing pad used in highly accurate polishing. Such a polishing pad secures a pore structure by the hollow fine spheres dispersed in polyurethane, and is endowed with high modulus of elasticity to a certain extent and rendered highly hard by the fine hollow spheres, thus improving flatness (relationship between the difference in level of a convex in a pattern in a device wafer and an abrasion loss of a concave in the pattern by polishing) to a certain extent. For example, IC-1000™ manufactured by Rodel is known as such a polishing pad. The hollow fine spheres can achieve high modulus of elasticity to a certain extent, but does not satisfy sufficient flatness because its effect of achieving high modulus of elasticity is limited due to the presence of the hollow structure. As is also described in a book, Toshiro Dohi et al.: Detailed Semiconductor CMP Techniques (in Japanese), Kogyo Chosakai, page 117 (2000), a hard pad capable of further improving flatness is necessary in consideration of application to elements in the next generation.
Further, a polishing pad having finely foamed or thermally foamed, fine hollow spheres dispersed in polyurethane is also described in JP-A 11-322877, JP-A 11-322878 etc. In particular, JP-A 11-322878 proposes a polishing pad having specific fine hollow spheres of finely foamed or thermally foamed polystyrene dispersed therein. However, such a polishing pad is not endowed with high modulus of elasticity and does not satisfy sufficient flatness.
Accordingly, an object of this invention is to provide a polyurethane composition capable of forming a polishing pad having a pore structure and being excellent in flatness.
For the purpose of improving flatness, a non-foamed hard polishing pad (for example, IC-2000™, manufactured by Rodel) can be used. As shown in the book supra (the same page supra), however, such a hard polishing pad causes the problem of scratches on the polished surface of a workpiece. The non-foamed polishing pad cannot sufficiently retain slurry abrasive grains on the surface of the polishing pad during polishing, and is thus not desirable from the viewpoint of polishing speed.
A polishing pad endowed with high elasticity by dispersing rigid solid beads in place of the hollow fine spheres is anticipated to improve the flatness of the polishing pad. Although flatness is improved by endowing the polishing pad with highly elasticity, the uniformity of a wafer as a whole is deteriorated when such a polishing pad is used. That is, both flatness and uniformity cannot be satisfied by merely dispersing rigid beads such as polystyrene beads. Further, the polishing pad endowed with high elasticity has a serious problem of scratches (scars) of the polished surface of a workpiece.
Use of polyurethane as the matrix resin forming the polishing pad is appreciated as described above. Such polyurethane is produced generally by curing an isocyanate-terminated prepolymer with a chain extender. A chlorine atom-containing chain extender such as 4,4′-methylenebis(o-chloroaniline), which is poor in reactivity and readily regulates curing reaction, is used as the chain extender. However, polyurethane (polishing pad) obtained by using the chlorine atom-containing chain extender as a starting material generates dangerous dioxins upon combustion after use and is thus not capable of thermal recycling (thermal recovery by combustion), thus raising a problem that there is no method for disposal except for landfill disposal.
Accordingly, an object of this invention is to provide a polyurethane composition capable of forming a polishing pad which can satisfy both flatness and uniformity and can reduce scratches. A still other object of this invention is to provide a polyurethane composition being capable of flatness improvement and scratch reduction which cannot be simultaneously achieved by the conventional polishing pad, being capable of thermal recycling of the polishing pad after use, and being not harmful to the environment.

This patent is subject to a terminal disclaimer.

Polyurethane composition and polishing pad


A semiconductor device in which stable and low resistance ohmic contact can be obtained in a base contact region without decreasing the emitter-base reverse breakdown voltage and the current amplification factor is disclosed. In this semiconductor device, p.sup.++ -type base contact layer 8 having an impurity concentration higher than that of p.sup.+ -type base layer 5 is formed in a region spaced apart by a predetermined distance from n.sup.+ -type emitter layer 7 on the main surface of p.sup.+ -type base layer 5. Thus, p.sup.++ -type base contact layer 8 having a high concentration does not contact n.sup.+ -type emitter layer 7, and also the current amplification factor and the emitter-base breakdown voltage are not decreased. Since p.sup.++ -type base contact layer 8 is formed so as to have a diffusion depth shallower than that of n.sup.+ -type emitter layer 7, the lateral spread of p.sup.++ -type base contact layer 8 can be reduced. Therefore, the side of p.sup.++ -type base contact layer 8 having a high concentration can be effectively prevented from contacting the side of n.sup.+ -type emitter layer 7 even when the elements are made smaller.

1. Field of the Invention
The present invention relates to semiconductor devices and a manufacturing method thereof, and more particularly, to a semiconductor device having a bipolar transistor and a manufacturing method thereof.
2. Description of the Background Art
Conventionally, a bipolar transistor is known as one of semiconductor elements. FIG. 22 is a cross section of a semiconductor device including a conventional bipolar transistor. Referring to FIG. 22, a conventional semiconductor device having a bipolar transistor includes a p.sup.+ -type silicon substrate 101; an n.sup.+ -type buried diffusion layer 102 which is formed in a predetermined region on a main surface of p.sup.+ -type silicon substrate 101; an n.sup.- -type epitaxial layer 103 which is formed on the entire main surface of p.sup.+ -type silicon substrate 101; a p.sup.+ -type isolation layer 104 which is formed in a predetermined region of n.sup.- -type epitaxial layer 103; an n.sup.+ -type collector layer 106 which is formed in a predetermined region on a main surface of n.sup.- -type epitaxial layer 103 surrounded by p.sup.+ -type isolation layer 104; a p.sup.+ -type base layer 105 which is formed in a region on the main surface of n.sup.- -type epitaxial layer 103 spaced apart by a predetermined distance from n.sup.+ -type collector layer 106; and an n.sup.+ -type emitter layer 107 which is formed in a predetermined region on a main surface of p.sup.+ -type base layer 105.
Also, a conventional semiconductor device having a bipolar transistor includes an insulating oxide film 109 which is formed on the main surface of n.sup.- -type epitaxial layer 103 and having contact holes 109a, 109b, and 109c formed respectively on n.sup.+ -type emitter layer 107, p.sup.+ -type base layer 105, and n.sup.+ -type collector layer 106; titanium silicide (TiSi.sub.2) films 110a, 110b, and 110c which are formed to contact the surface of n.sup.+ -type emitter layer 107, p.sup.+ -type base layer 105, and n.sup.+ -type collector layer 106 respectively in contact holes 109a, 109b, and 109c; titanium nitride (TiN) films 111a, 111b, and 111c which are formed respectively on titanium silicide films 110a, 110b, and 110c; aluminum interconnection films 112a, 112b, and 112c which are formed respectively on titanium nitride films 111a, 111b, and 111c; and a protection film 113 which is formed to cover the entire surface.
Titanium silicide films 110a, 110b, and 110c are formed to make ohmic contact with n.sup.+ -type emitter layer 107, p.sup.+ -type base layer 105 and n.sup.+ -type collector layer 106 respectively. Titanium nitride films 111a, 111b, and 111c serve as barrier layers for preventing aluminum alloy spike caused by aluminum interconnection layers 112a, 112b, and 112c formed thereon. A collector region is structured by n.sup.- -type epitaxial layer 103 and n.sup.+ collector layer 106 in a region surrounded by p.sup.+ -type isolation layer 104.
FIGS. 23-31 are cross sectional views showing a manufacturing process of a semiconductor device including a conventional bipolar transistor shown in FIG. 22. Referring to FIGS. 23-31, a manufacturing process of a conventional semiconductor device will be described.
As shown in FIG. 23, n.sup.+ -type buried diffusion layer 102 is formed in p.sup.+ -type silicon substrate 101. Then, n.sup.- -type epitaxial layer 103 is formed on the entire surface of p.sup.+ -type silicon substrate 101. p.sup.+ -type isolation layer 104 is formed in a predetermined region of n.sup.- -type epitaxial layer 103. Insulating oxide film 109 is formed on a main surface of n.sup.- -type epitaxial layer 103.
As shown in FIG. 24, p-type impurity is introduced via insulating oxide film 109 into a predetermined region on the main surface of n.sup.- -type epitaxial layer 103 surrounded by p.sup.+ -type isolation layer 104 through, for example, the ion implantation method. Then, p.sup.+ -type base layer 105 having resistance value of 100-1000 .OMEGA./.quadrature., diffusion depth of 0.3-1.5 .mu.m, and surface impurity concentration of about -5.times.10.sup.18 cm.sup.-3 is formed by activating the introduced p-type impurity.
As shown in FIG. 25, a photoresist 120 is formed by using photolithography in a predetermined region on insulating oxide film 109. Using photoresist 120 as a mask, insulating oxide film 109, where an emitter electrode, a base electrode and a collector electrode of the bipolar transistor are to be made, is etched anisotropically, and thereby contact holes 109a, 109b, and 109c are formed. Photoresist 120 is then removed.
As shown in FIG. 26, a photoresist 121 is formed by using photolithography so as to cover the region, where the base electrode of the bipolar transistor is to be made, is formed. Then, n-type impurity such as arsenic ions (As.sup.+) is implanted on the entire surface. Photoresist 121 is then removed. Then, n.sup.+ -type collector layer 106 and n.sup.+ -type emitter layer 107 are formed as shown in FIG. 27 by activating the ion-implanted impurity.
As shown in FIG. 28, titanium (Ti) film 122 having a thickness of the range from about 40 to about 100 nm is formed. Then heat treatment is conducted for about 30 seconds in N.sub.2 atmosphere under the temperature condition of 750.about.850.degree. C. Thereby, titanium silicide films 110a, 110b, and 110c and titanium nitride layer 111 are formed as shown in FIG. 29. More particularly, titanium silicide films 110a, 110b, and 110c are formed by silicide reaction between titanium film 122 (see FIG. 28) and silicon in n.sup.- -type epitaxial layer 103, while the rest of titanium film 122 (see FIG. 28) is nitrided by N.sub.2 gas to be titanium nitride layer 111.
As shown in FIG. 30, aluminum interconnection layer 112 is formed on titanium nitride layer 111. A photoresist 123 is formed by photolithography at a predetermined region on aluminum interconnection layer 112. Using photoresist 123 as a mask, titanium nitride films 111a, 111b, and 111c and aluminum interconnection films 112a, 112b, and 112c are formed as shown in FIG. 31 by etching aluminum interconnection layer 112 and titanium nitride layer 111 anisotropically. Resist 123 is then removed.
Finally, as shown in FIG. 32, protection film 113 is formed on the entire surface. The conventional semiconductor device having a bipolar transistor is thus completed.
As mentioned above, in the conventional semiconductor device having a bipolar transistor, titanium silicide films 110a, 110b, and 110c are formed by utilizing silicide reaction between titanium layer 122 and substrate silicon so as to obtain ohmic contact with n.sup.+ -type emitter layer 107, p.sup.+ -type base layer 105, and n.sup.+ -type collector layer 106.
However, p-type impurity in p.sup.+ -type base layer 105 is taken in titanium silicide film 110b due to silicide reaction between titanium and silicon. FIG. 33 is an impurity profile along line X.sub.1 --X.sub.1 in a step before silicide reaction shown in FIG. 28. FIG. 34 is an impurity profile along line X.sub.2 --X.sub.2 in a step after silicide reaction shown in FIG. 29. Referring to FIGS. 33 and 34, the surface impurity concentration in p.sup.+ -type base layer 105 is about 5.times.10.sup.8 cm.sup.-3 before silicide reaction: however, it is noted that the surface impurity concentration in p.sup.+ -type base layer 105 is lowered to about 5.times.10.sup.16 cm.sup.-3 after silicide reaction. This is because p-type impurity in p.sup.+ -type base layer 105 is taken in titanium silicide (TiSi.sub.2) film 110b which is formed by silicide reaction, as shown in FIG. 34.
FIG. 35 is an impurity profile along line A.sub.1 --A.sub.1 in the semiconductor device which is completed finally as shown in FIG. 32, and FIG. 36 is an impurity profile along line B.sub.1 --B.sub.1 of the same. Referring to FIG. 35, in the impurity profile along line A.sub.1 --A.sub.1 of the finished semiconductor device (see FIG. 32), the impurity concentration in p.sup.+ -type base layer 105 is lowered down to 5.times.10.sup.16 cm.sup.-3 by silicide reaction as described above. Here, as shown in FIG. 36, the impurity concentration in n.sup.+ -type emitter layer 107 (see FIG. 32) is not lowered so much by silicide reaction as p.sup.+ -type base layer 105. This is because n-type impurity is hardly taken in silicide layer generally, and at the same time the impurity concentration in n.sup.+ -type emitter layer 107 was originally high. Accordingly, the impurity concentration in n.sup.+ -type collector layer 106, which is the same n-type as the emitter layer 107, is not so much lowered by silicide reaction. Thus, only p.sup.+ -type base layer 105 is affected by silicide reaction, and, the problem is the decrease of the impurity concentration in p.sup.+ -type base layer 105.
More particularly, the resistance of the base contact increases if the surface impurity concentration of p.sup.+ -type base layer 105 decreases due to silicide reaction. FIG. 37 is a graph showing correlation of the impurity concentration at interface between titanium silicide (TiSi.sub.2) and silicon (Si) and the resistance value of the base contact. Referring to FIG. 37, it is noted that if the impurity concentration at interface between titanium silicide and silicon, i.e., the surface impurity concentration in p.sup.+ -type base layer 105, decreases, then the resistance value of the base contact increases abruptly. More specifically, after silicide reaction the resistance value of the base contact increases up to about 1000 times that before silicide reaction. Hence, the problem was that the operating speed of the bipolar transistor decreased if the resistance value of the base contact increased.
Also, the base contact resistance comes to depend on temperature as the surface impurity concentration in p.sup.+ -type base layer 105 decreases due to silicide reaction. FIG. 38 is a graph showing a relationship of the temperature when the surface impurity concentration N in p.sup.+ -type base layer 105 is not more than 1.0.times.10.sup.17 cm.sup.-3 and of the resistance value of the base contact. Referring to FIG. 38, a remarkable temperature dependency is developed in the resistance of the base contact when the surface impurity concentration N of p.sup.+ -type base layer 105 is lowered to 1.0.times.10.sup.17 cm.sup.-3 or lower. In other words, the resistance of the base contact decreases as the temperature rises. This phenomenon becomes outstanding as the current decreases. This phenomenon is disclosed, for example, in VLSI TECHNOLOGY edited by S. M. Sze, pp. 347-350. Thus, as the temperature dependency is developed in the resistance of the base contact, the circuit characteristics change because of temperature.
Conventionally, the resistance of the base contact increases because the surface impurity concentration in p.sup.+ -type base layer decreases by silicide reaction, causing much temperature dependency of the resistance of the base contact. In addition to silicide reaction, conventionally, oxidization of the surface of p.sup.+ -type base layer or the like causes decrease of the surface impurity concentration of p.sup.+ -type base layer.
The following is a possible structure in order to solve such problems. FIG. 39 is a cross sectional view showing the proposed example. Referring to FIG. 39, a p.sup.++ -type base layer 205 which has a higher impurity concentration compared to the conventional one is applied in this proposal. If p.sup.++ -type base layer 205 of a higher impurity concentration is formed, even though the surface impurity concentration in p.sup.++ -type base layer 205 is decreased by silicide reaction, etc., the decrease of surface impurity concentration to 10.sup.8 cm.sup.-3 or lower can be easily prevented. Accordingly, problems such as increase of the resistance of the base contact and occurrence of temperature dependency of the resistance of the base contact can be solved.
However, when p.sup.++ -type base layer 205 which has a higher impurity concentration is formed, the difference of impurity concentrations at interface between p.sup.++ -type base layer 205 and emitter layer 107 is increased. Thus, it becomes difficult for electrons from n.sup.+ -type emitter layer 107 to pass through p.sup.++ -type base layer 205, and accordingly an amplification factor between an emitter and base is decreased. Also, if the difference of impurity concentrations at interface between p.sup.++ -type base layer 205 and n.sup.+ -type emitter layer 107 becomes large, it leads to electric field concentration, so that the emitter-base reverse breakdown voltage of is decreased. Thus, when p.sup.++ -type base layer 205 having a higher impurity concentration is used for preventing decrease of the surface impurity concentration in the base layer due to silicide reaction, etc., various problems will occur.

Semiconductor device including a bipolar transistor


Embodiments of methods and apparatus for operating an ensemble of wireless electronic devices based on user activity are generally described herein. Other embodiments may be described and claimed.

As technology advances to provide greater mobility, more and more people are carrying and using multiple wireless electronic devices (i.e., an ensemble) for a variety of reasons such as work, education, and/or entertainment. For example, a person may carry and use an ensemble of wireless electronic devices including a laptop computer, a handheld computer, a tablet computer, a wireless (e.g., cordless or cellular) telephone, a pager, an audio and/or video player (e.g., an MP3 player or a digital video disc (DVD) player), a gaming device, a digital camera, a navigation device (e.g., a global positioning system (GPS) device), and/or wireless peripherals (e.g., a headset, a keyboard, a mouse, etc.).

Methods and apparatus for operating an ensemble of wireless electronic devices based on user activity


Systems, methods, techniques, and apparatuses of a medium voltage alternating current (MVAC) network are disclosed. One exemplary embodiment is a direct current (DC) interconnection system for an MVAC distribution network including an AC/AC power converter including a first AC terminal and a second AC terminal; a plurality of switching devices structured to selectively couple a first AC terminal to a plurality of feeder line points in the MVAC network; and a control system structured to receive a set of measurements, calculate a headroom value for each feeder line point using the set of measurements, select a first feeder line point using the calculated headroom values, operate the plurality of switching devices so as to couple the first AC terminal to the first feeder line point, and operate the AC/AC power converter so as to transmit MVAC power from the first AC terminal to the first feeder line point.

The present disclosure relates generally to medium voltage alternating current (MVAC) distribution networks. As high-demand loads and distributed energy resources are added to MVAC and low voltage alternating current (LVAC) distribution networks, different portions of the same network may experience mismatched power demands. Existing MVAC distribution networks suffer from a number of shortcomings and disadvantages. There remain unmet needs including increasing reliability, minimizing capacity constraints, and reducing power losses. For instance, a feeder line of an MVAC network may transmit power close to line capacity causing significant power losses and thermal stresses compared to another feeder line of the same MVAC network transmitting power significantly lower than line capacity. Balancing headroom by connecting the feeders using a tie switch arranges a network in a meshed configuration, requiring additional power flow control and protection. Furthermore, closing a tie switch may not be possible due to differences in voltage or phase angle. In view of these and other shortcomings in the art, there is a significant need for the unique apparatuses, methods, systems and techniques disclosed herein.

Distribution networks with flexible direct current interconnection system


An energy-supply rotary inertia driver system for an offshore platform includes an annular fixed plate, an active control module, a wind power generation module and a solar power generation module. The system can monitor a motion state of the offshore platform in real time, and can generate a force through the active control module if necessary to apply a force torque of the offshore platform to further achieve the vibration suppression. Moreover, when the offshore platform is under normal operation, the system can act as an energy supply device via wind and solar power generation to feed electric energy to the active control module and other electrical equipment on the offshore platform when needed.

With the implementation of "Sea Power" strategy, large-scale marine equipment such as offshore platforms and heavy ships has been continuously built, and the construction techniques of the offshore platforms also receive rapid development. The offshore platform is an important structure that provides production and living facilities for drilling, oil production, transportation, observation, navigation and construction, so its security and stability must be fully considered during the design stage. In addition, the offshore platform often undergoes vibration in use under the action of an external load, and if the external load is large enough, a swing and even destruction may occur. In order to avoid various problems caused by structural vibration, the vibration control technology has been developed. The vibration control technology is mainly divided into active control, passive control, semi-active control and hybrid control. For a given structure, the installation of an appropriate vibration control device can effectively reduce the dynamic response of the structure, alleviating the destruction or fatigue damage caused by the vibration to the structure.
However, the movement of a structure is usually a combination of translation and torsion vibration. It has been found that the control device such as a translational tuned mass damper, an active mass damper (AMD) and an active torque output device, due to the need to provide a centripetal force in the torsion vibration, is greatly weakened in the control effect on the controlled structure, and even completely loses its function, failing to effectively control the swing vibrations. There are many motion forms involving the swing vibration, such as the torsion vibration of the offshore platform under the coupling effect of wave, wind and ice; the swing of a suspended structure; the torsion vibration of irregular buildings under the wind load; the torsion vibration caused by position adjustment and opening of a solar panel during the operation of a spacecraft and a space structure; and the torsion vibration in a high-speed train due to small excitations. Therefore, it is required to design a special control device, which overcomes (or gets rid of) the influence of the gravity field on the control device itself (effect of centrifugal force), or decoupling its work/motion law from the gravity field so that the natural vibration would not be affected by gravity, providing an effective control.
At present, the vibration isolation is the most commonly-used vibration control technology for offshore platforms, in which an isolation layer is appropriately provided in the offshore platform structure to reduce the response of a superstructure of the offshore platform. However, the vibration isolation can merely provide limited control for vibration, particularly for swing vibration. Moreover, the employment of a tuned liquid damper still has some defects such as unsatisfactory control effect, failure in control of the swing vibration and complicated installation. Though the existing active control device can exert a desirable control effect in most cases, it still fails to be applied in the offshore platform structure due to the limitation in energy supply.
In summary, though the vibration control device plays an indispensable role in the offshore platforms, it still remains to be improved to overcome the following shortcomings.
(1) The existing vibration isolation technology in the offshore platforms has limited control effects and a complicated design.
(2) For the offshore platforms, the existing control devices such as TMD, TLD and AMD can only control the translation, but fails to control the swing vibrations.
(3) The passive rotary inertia tuned damper can effectively control the swing vibration, but it requires complex frequency modulation for the structure itself, moreover, for some complicated structures, it has the disadvantages of low efficiency, poor effect, low robustness, low controllability and small application range.
(4) The traditional active control devices can control the swing vibrations, but the control efficiency is extremely low, failing to meet the practical requirements. Besides, the active control devices can not guarantee the energy supply when used under complex working conditions, such as in the offshore platforms.

Energy-supply rotary inertia driver system for an offshore platform


A package for an orthodontic bracket or other dental product is formed by a container having a bottom and a plurality of sidewalls, creating a cavity within the container. One of the sidewalls is disposed at an angle greater than 90 degrees from the bottom so that it slants up and away from the bottom. This way, the opening in the top of the package is larger than the surface area of the bottom of the package. There is a removable top configured for covering the cavity. There is a quantity of pliable material attached to the bottom or to the slanted sidewall. The pliable material is configured to be able to hold a small object such as an orthodontic bracket in place when the object is pressed into the pliable material. The bracket is placed on the pliable material in such a way that adhesive disposed on the rear side of the bracket does not touch the pliable material or any other part of the bracket.

1. Field of the Invention
The present invention relates to a package for a pre-pasted orthodontic bracket. In particular, the invention relates to a package that supports the bracket in place while keeping the pre-pasted portion free from contact with any surface of the package.
2. The Prior Art
Modern orthodontic techniques include repositioning teeth that are misaligned, too close together or otherwise mis-positioned. In order to reposition the teeth, the teeth are connected to an arch wire that serves as a guide, urging the teeth into the desired position and orientation. In order to connect the teeth to the arch wire, small brackets with slots for receiving the arch wire are attached to the teeth. The brackets are usually attached to a patient's teeth by means of an adhesive.
Applying an appropriate amount of adhesive to the base of a bracket can be a time consuming and tedious. Too little adhesive may result in the bracket coming loose from the tooth after installation, while excessive amounts of adhesive will be pushed out from between the bracket and tooth, requiring removal. Further, while two-part chemically curing adhesive systems are available for bonding orthodontic brackets to a patient's teeth, many practitioners prefer photo sensitive adhesives that are cured upon exposure to light in the visible spectrum for a relatively short period. Consequently, time is also a factor insofar as the adhesive applied to the bracket can only be exposed to visible light for a limited period before the bracket is positioned on the tooth.
In order to address these issues, pre-pasted orthodontic appliances were developed. Pre-pasted orthodontic appliances have an adhesive, normally a photo sensitive, light curing adhesive, applied to the base of the bracket before the bracket is packaged. Pre-pasted brackets reduce the amount of time required to install brackets on the patient's teeth by eliminating the need for the orthodontist to apply the adhesive to the bracket. Pre-pasted brackets also reduce the amount of wasted adhesive as the manufacturer can precisely control the amount and placement of the adhesive on the base of the bracket.
Packaging for brackets with a pre-applied light curing adhesive must protect the adhesive from exposure to light, as well as from contamination and evaporation. Further, if the adhesive adheres to the package, the adhesive coating may be disturbed when the bracket is removed from the package. In addition, the package should present the bracket to the orthodontist in a fashion that facilitates quick and convenient removal of the bracket from the package. For example, U.S. Pat. No. 7,381,053 discloses a package for a pre-pasted orthodontic bracket in which the bracket is suspended on a skirt that holds the bracket above the bottom of the packaging. U.S. Pat. No. 4,978,007 shows a package where the bracket is suspended on a jig that extends across a cavity in the package, so that the adhesive does not contact the bottom of the package.
While these packages prevent the adhesive from contacting the walls of the packaging, they are expensive and cumbersome to produce, usually requiring several different parts that have to be assembled.


Disclosed are methods, software, and systems for comparing biopolymer sequences. The model includes at least two different characterizations of states of matching between segments of sequences at defined positions. Examples of states of matching include: similarity and dissimilarity between objects, as well as similarity to a reference, e.g., a reference sequence or a sequence profile. A topology of particular match states can be used to identify classes of sequences, e.g., preprohormone sequences.

The invention relates to comparing biopolymer sequences. Nucleic acids and proteins are two types of biopolymers that have complex sequences. Nucleic acids are polymers composed of a sequence of nucleotides. At a given position, one of four nucleotides can be present. One function of nucleic acids is to encode polypeptides.
Polypeptides are polymers composed of a sequence of amino acids. At a given position, one of twenty amino acids can be present. The sequence of amino acid in a polypeptide chain determines the structural fold that the polypeptide prefers to adopt. The properties of each amino acid side chain are unique and varied. Relevant properties for structure and function include hydrophobicity, size, charge, and rotamer preference.
For analysis, polymer chains are typically represented as a string of alphabetical characters, each character abbreviating the identity of a monomer in the chain. It is known to classify biopolymer sequences by their similarity to characterized sequences. Function is then imputed on the basis of the classification. For example, a sequence that is 70% identical to a protease and is 100% identical at residues demonstrated to mediate the enzymatic function of proteases is likely form a compound with protease activity.
Determining similarity for protein sequences is nontrivial for at least the following reasons. First, similar protein sequences can include insertions or deletions that shift the frame of comparison. Second, whereas two identical amino acids at a given position are clearly similar, measures of similarity of any two non-identical amino acids can fall within a large range. Further, the same pair of non-identical amino acids that function similarly in one context, may not in another context.
A variety of computer-based techniques have been developed to compare protein sequences. For example, the BLAST algorithm (Basic Local Alignment Search Technique; e.g., described by Altschul, et al. (1990) J. Mol. Biol. 215:403–10) allows for gaps of various sizes. A scoring scheme penalizes gaps, the enlargement of gaps, and non-identity. Further, a matrix that describes all possible pairs of amino acids at a given position is used to determine the extent of non-similarity at the position.
It is also possible to compare a biopolymer sequence to a profile of a family of similar sequences. This comparison can be made using an implementation of a Hidden Markov Model (HMM). Profile HMMs are a class of probabilistic models particularly adept for profile searches of biological sequences (Churchill (1989) Bull. Math. Biol. 51:79–94; Krogh et al. (1994) J. Mol. Biol. 235:1501–1531; Hughey and Krogh (1996) Computer Applications in the Biosciences 12:95–107; Eddy et al. (1995) J. Comp. Biol. 2:9–23; Durbin et al. (1998) Biological Sequence Analysis: Probabilistic Models of Proteins and Nucleic Acids Cambridge University Press; Gribskov et al. (1987) Proc. Natl. Acad. Sci. USA 84:4355–58). Profile HMMs include a network of nodes. Nodes are used to indicate the probability of a given monomer at a particular sequence position "emit" monomers at particular sequence positions. The probability depends on the frequency of the given monomer at the particular position in the family of similar sequences. Traversal of a path across the network of nodes of a profile HMM produces a single sequence that a likely family member.


A grounded FRL for treating a pressurized air supply has a housing with a connecting mechanism for connecting to a collector bowl. The collector bowl is made from a metal base material and has an open end with a connecting mechanism and a closed distal end. The housing has a flange that is electrically conductive and extending downwardly at an exterior of the bowl. At least one grounding clip member is made from electrically conductive material and has an exterior mounting end attached to the flange for electrical connectivity thereto and has a radially inner end that electrically makes contact with the metal base materials of the collector bowl and the housing.

Industrial automation uses many control devices that are often powered or actuated by pneumatics. Pressurized air supplies need to be treated, e.g. filtered, regulated and/or lubricated before going to valves and actuators. Often the filters, regulators and lubricators used to treat the air supply share many components and look alike and are often installed in line in proximity to each other or even assembled togethers in combinations. The industry often refers to any individual filter, regulator, or lubricator assembly as an FRL. In this document, "FRL" will generically refer to a filter, regulator, or lubricator assembly or any combination thereof for use in treating a pressurized air supply.
The housing of an FRL (often referred to in the industry as an FRL head) is commonly grounded by being electrically connected to the incoming and outgoing piping that carries the air. Another part of the FRL is a collector bowl that is used to house the filter. The collector bowl is not directly connected to the piping but is screwed on or otherwise fastened to the housing. An intermittent problem however may occur with any FRL collector bowl because the quantity of air that passes into and out of the bowl often carries an electrical charge that can transfer to and build up in the collector bowl. If the bowl is not grounded to the housing, the static electrical buildup may build up to the point of causing an uncontrolled spark which is often undesireable in an industrial setting. Consequently, the collector bowls are commonly made from metal and attempts are made to ground it to the housing. However, it is common for a collector bowl and housing to be painted for cosmetic and protective reasons which may undesirably electrically insulate the metal of the collector bowl from the housing. Efforts have been made to provide the painted collector bowl and the painted housing with metal to metal contact such that the collector bowl is grounded through the housing and to the piping. However, due to manufacturing tolerances and the consequentially possible loose fitting of the metal to metal connection, between the collector bowl and housing, the connection may be intermittently interrupted which then allows a buildup of static electricity.
What is desired is a reliable grounding system that establishes a reliable and physical metal-to-metal connection between the bowl and housing to ground the components together and prevent build-up of electrical charge. What is also desired is a spring-loaded metal-to-metal connection that provides a positive contact that compensates for any loose fitting due to manufacturing tolerances. What is also desired as an expedient and inexpensive connection system to electrically ground the bowl to the housing of an FRL that is cosmetically acceptable.


The present invention is directed to a process for producing an aqueous cathodic electrocoating composition comprising. A) mixing PA1 B) salting with an acid and PA1 C) dispersing in deionized water.. i) a powder comprising a dispersion of a pigment in a solid resin PA2 ii) a principal resin PA2 iii) a crosslinker and optionally PA2 iv) an additive selected from the group consisting of organic solvents, catalysts, wetting agents, conditioning agents, thickeners, rheology control agents, antioxidants, surfactants, leveling agents and mixtures thereof

Cathodic electrodeposition as a coating application method for metallic substrates is well known and discribed for example in U.S. Pat. Nos. 4,575,523; 4,661,541; 4,780,524 and 4,920,162.
The electrocoating composition comprises the cationic resin (principal resin), a crosslinker, a grind resin, pigments and other additives such as solvents, control agents, fillers and the like.
Typically, a principal resin is prepared by adducting an epoxy resin with an amine. An aqueous electrodeposition coating bath is prepared by mixing the principal resin with a crosslinking agent and salting it with acid and deionized water to form a dispersion, mixing the dispersion with a pigment paste and optionally with other additives like solvents, antifoam and the like.
Pigment pastes are usually prepared by dispersing a pigment in a grinding resin in the presence of plasticizers, wetting agents, surfactants or other ingredients in a ball mill, sand mill, cowles mill or continuous mill until the pigment has been reduced to the desired particle size and is wetted by the resin or dispersed in it.
One disadvantage of pigment pastes is that they contain volatile organic compounds.
It is therefore an object of the present invention to provide a process for the preparation of a cathodic electrocoating composition with very low VOC but good pigment dispersibility comprising a powder of a dispersion of a pigment in a solid resin. Another object of the invention is an aqueous cathodic electrocoating composition. Another object of the invention is a process for the preparation of an aqueous electrocoating composition from a one component electrocoating composition.

Electrocoating composition comprising the solid pigment dispersion


Systems and methods for integrated glycerol carbonate and/or urea production. This disclosure pertains to development of a process for production of glycerol carbonate and/or urea from ammonia, carbon dioxide and glycerol. The process integrates glycerol carbonate production into a urea production process. The urea produced in the production facility may be used to produce glycerol carbonate by reacting urea with glycerol. The ammonia generated by glycerol carbonate production may be recycled back to urea production. Unreacted urea from the glycerol carbonate production may be separated and recycled to the urea product stream. The systems and methods can reduce the cost for urea production and increase product value of the excessive glycerol produced from other chemical plants.

In existing industrial processes, glycerol is formed as a byproduct of fatty acids and fatty alcohols production. Due to a recent increase in biofuels and biolubricants production, which generates an increased amount of glycerol, the current market for glycerol is over-saturated. Consequently, the price of glycerol has been driven down. In so far as many chemical companies see the risk of glycerol becoming chemical waste, a solution to integrate a process that consumes glycerol and generates products of higher value in traditional chemical facilities has become highly desirable.
Current chemical production processes that consume glycerol include manufacturing of glycerol carbonate (glycerine carbonate or 4-hydroxymethyl-2-oxo-1,3-dioxolane) from glycerol. For instance, U.S. Pat. No. 8,314,259 describes a glycerol carbonate production process using a lipase of bio-catalyst to react with a reactant solution, which is prepared by adding glycerol, a glycerol-containing composition, or a dimethyl carbonate in a reaction solvent. U.S. Pat. No. 6,025,504 discloses a method for producing glycerol carbonate from urea and glycerol using catalyst bearing Lewis acid sites. However, the capital expenditure and subsequent operating cost for these methods can be high, thereby limiting the economic feasibility of glycerol carbonate production.

Integrated process for production of glycerol carbonate (4-hydroxymethyl-2-oxo-1, 3-dioxolane) and urea