The rheological properties of a crosslinkable resin system are modified by the presence of a side chain crystalline (SCC) polymer (or a similar crystalline polymer which melts over a narrow temperature range). The polymer dissolves in the curable system at temperatures above the melting point of the crystalline polymer (Tp), but when the system is then cooled to a temperature below Tp, at least partially forms a separate phase in the curable system. Below Tp, this separate phase substantially increases the viscosity of the curable system (i.e. makes it thicker than the same system without the crystalline polymer). This is particularly valuable for sheet molding composites (SMCs) in which the increase in viscosity makes the composites less tacky, and for dry film resists (DFRs). Above Tp, the curable system containing the dissolved crystalline polymer has a viscosity which is substantially less than its viscosity below Tp.

1. Field of the Invention
This invention relates to polymeric materials which modify the rheological behavior of crosslinkable resin systems.
2. Introduction to the Invention
Crosslinkable resin systems are well known. It is known that in order to produce such a system which is relatively stable in storage, one of the active chemical moieties (e.g., a catalytic moiety or a reactive moiety) can be present in a xe2x80x9clatentxe2x80x9d form, which can be activated (by heating or otherwise) when rapid reaction is desired. Reference may be made for example to U.S. Pat. Nos. 4,349,651, 4,358,571, 4,420,605, 4,430,445, 4,659,779, 4,689,388, 4,701,378, 4,742,148 and 4,933,392 and European Patent Publication No. 362787A2. Copending, commonly assigned, U.S. application Ser. Nos. 08/726,739, 08/726,740 and 08/726,741 , all abandoned (each of which was filed Oct. 15, 1996 and claims priority from U.S. application Ser. No. 08/399,724 filed Mar. 7, 1995, now abandoned) and corresponding International Application No. PCT/US96/03023 (published Sep. 12, 1996, as International Publication No. WO-96/27641) disclose particularly valuable latent materials comprising an active chemical moiety which is bonded to a side chain crystalline (SCC) polymer moiety or to another crystalline polymeric moiety which melts over a narrow temperature range. These latent materials, which are referred to in the applications as polymeric modifying agents, are preferably in the form of particles having an average size of 0.1 to 50 microns. Copending, commonly assigned U.S. application Ser. No. 08/710,161 (Docket No. 10762-4 filed Sep. 12, 1996), abandoned, and corresponding International Application No. PCT/US 97/16019 (which was not published at the date of this application) disclose that even when there is no chemical bond between the active and polymeric moieties, a physical bond between the moieties can produce a lesser but still useful latent effect. Application Ser. Nos. 08/726,739, 08/726,740, 08/726,741 and 08/710,161 have all been abandoned in favor of a continuation-in-part application, Ser. No. 09/216,520, filed Dec. 16, 1998, U.S. Pat. No. 6,255,367. It is also known that curable resin systems tend to shrink when they cure, and that in some systems this tendency can be lessened or overcome by adding various polymeric additives; such additives are referred to as low profile additives (often abbreviated to xe2x80x9cLPAxe2x80x9ds). Reference may be made for example to pages 48 to 78 (Chapter 4 by Kenneth E. Atkins) in xe2x80x9cSheet Molding Compoundsxe2x80x9d, edited by Hamid Kia (1993), Plastics Compounding, July/August 1988, pages 35-45, and U.S. Pat. Nos. 3,674,893, 3,718,714, 3,721,642, 3,772,241, 3,842,142, 4,125,702, 4,160,759, 4,161,471, 4,245,068, 4,284,736, 4,288,571, 4,374,215, 4,491,642, 4,555,534, 4,673,706, 5,290,854, 5,428,105, 5,504,151, 5,552,478 and 5,589,538.
The disclosure of each of the U.S. patents and patent applications, International and European patent publications, and literature references referred to in the preceding paragraph is incorporated herein by reference for all purposes.
We have discovered, in accordance with the present invention, that the rheological properties of a crosslinkable resin system can be substantially improved by the presence of an SCC polymer (or a similar crystalline polymer which melts over a narrow temperature range). The polymer must be one which (a) at least partially dissolves in the curable system at temperatures above the melting point of the crystalline polymer (Tp) and (b) when the curable composition is (i) heated to a temperature above Tp under conditions such that the resin does not cure and (ii) is then cooled to a temperature below Tp, at least partially forms a separate phase in the curable system. At temperatures below Tp, the presence of this separate phase substantially increases the viscosity of the curable system (i.e. makes it thicker than the same system without the crystalline polymer). This is particularly valuable for sheet molding composites (SMCs), in which the increase in viscosity makes the composites less tacky and, therefore, (a) easier to handle cleanly, and (b) more likely to yield a cured product having a surface free from flaws. Above Tp, the curable system containing the dissolved crystalline polymer has a viscosity which is substantially less than its viscosity below Tp.
The crystalline polymer can be, but need not be, chemically or physically bound to an active chemical moiety which will take part in the reaction which forms the cured polymer. We believe, therefore, that under appropriate circumstances, some latent materials of the kind described in the copending, commonly assigned U.S. patent applications referred to above will function as RHMs. However, that possibility is not disclosed in those U.S. patent applications or the corresponding PCT applications. Under these circumstances, the extent to which our discovery can be the subject of patent protection may vary from country to country. Accordingly, and since this specification will serve not only as the specification for this U.S. patent application, but also as the priority document for corresponding applications elsewhere, the present invention is broadly defined as any product or process which embodies our discovery and which can properly be the subject of patent protection.
In a first preferred aspect, this invention provides a polymeric composition which comprises
1. a matrix material which
(a) provides a continuous phase, and
(b) comprises precursors which will react together to form a crosslinked polymer;
and
2. a rheological modifier (RHM) which
(a) comprises a crystalline polymer having an onset of melting temperature To and a peak melting temperature Tp which is (i) from 20xc2x0 C. to 200xc2x0 C., and (ii) such that Tpxe2x88x92To is less than Tp0.7,
(b) is uniformly distributed in the matrix material,
(c) is at least partially soluble in the matrix material when the composition is subjected to a treatment which consists of maintaining the composition at a temperature above Tp under conditions such that the precursors do not react together to form a crosslinked resin, and
(d) becomes at least partially insoluble in the matrix material when the composition is subjected to said treatment at a temperature above Tp and is then cooled to a temperature below To,
the composition
(A) having a viscosity above Tp which is less than its viscosity below To; and
(B) having a viscosity at a temperature below To which is substantially greater than the viscosity at the same temperature of a composition which is identical except that it does not contain the rheological modifier.
Preferably, the matrix material and the RHM and the relative amounts thereof are such that (a) the composition, or (b) if the composition contains solid fillers, a composition which is identical except that it does not contain the solid fillers, (A) has a viscosity at (Tpxe2x88x9210)xc2x0 C. which is at least twice, preferably at least 5 times, its viscosity at (Tp+10)xc2x0 C.; and/or (B) has a viscosity at 20xc2x0 C. which is at least twice, preferably at least 5 times, the viscosity of a composition which is identical except that it does not contain the RHM.
The composition may also have at least one of the following characteristics, each of which provides an alternative or additional distinction over the disclosure of the commonly assigned U.S. applications and their PCT equivalents referred to above.
(1) At least 10%, at least 20% or at least 30% of the crystalline polymer is present in the form of particles or other discrete volumes which do not contain any material which takes part in the reaction which forms the crosslinked polymer.
(2) The composition, when maintained at 40xc2x0 C., doubles in viscosity in less than 240 hours, e.g. in less than 24 hours.
(3) The RHM is not present in the form of discrete particles.
(4) The RHM is added to the matrix material in the form of particles having an average size of at least 75 microns, or as a solution in a solvent.
(5) When the composition is heated from (Tpxe2x88x9210)xc2x0 C. to (Tp+10)xc2x0 C., there is an increase by a factor of less than 50, e.g., less than 5, in the effective concentration of each of the materials which takes part in the reaction which forms the crosslinked polymer.
It is to be understood that these characteristics (1) to (5) are not intended to represent factors which will be technically advantageous.
In a second preferred aspect, this invention provides a method of making such a composition which comprises
(A) dispersing the RHM, e.g. a solution of the RHM or particles of the RHM, in at least part of the matrix material;
(B) heating the product of step (A) to a temperature above Tp under conditions such that the precursors do not react together to form a crosslinked polymer; and
(C) cooling the heated dispersion to a temperature below Tp.
In a third preferred aspect, this invention provides a method of making a crosslinked polymer which comprises subjecting a composition as defined above to conditions which cause the precursor to react to form a crosslinked polymer.
In this specification, parts and percentages are by weight, viscosities are in centipoise and are measured using a Brookfield LVT viscometer, temperatures are in xc2x0 C., and To, Tp and heat of fusion are determined using a differential scanning calorimeter (DSC), (at a rate of temperature change of 10xc2x0 C./min on the second heat by cycle). To and Tp are measured in the conventional way well known to those skilled in the art. Thus Tp is the temperature at the peak of the DSC curve, and To is the temperature at the intersection of the baseline of the DSC peak and the onset line, the onset line being defined as the tangent to the steepest part of the DSC curve below Tp. The abbreviations Mw and Mn are used to denote weight average and number average molecular weight respectively. The abbreviation CxA is used to denote an n-alkyl acrylate in which the n-alkyl group contains x carbon atoms, the abbreviation Cx alkyl is used herein to denote an n-alkyl group which contains x carbon atoms, and the abbreviations CxM is used to denote an n-alkyl methacrylate in which the n-alkyl group contains x carbon atoms. Other abbreviations are given elsewhere in the specification.
The terms xe2x80x9cmatrixxe2x80x9d and xe2x80x9cmatrix materialsxe2x80x9d are used in this specification to denote any material or mixture of materials comprising a precursor which will react with itself to form a crosslinked polymer, or two or more precursors which will react with each other to form a crosslinked polymer, or one or more precursors which will react with one or more additional materials (added at a later stage) to form a crosslinked polymer. One or more of the precursors can be in latent form. The matrix generally comprises at least one solid or liquid material which provides a continuous phase in which the RHM is distributed. The matrix can include, in addition to the precursor(s) and the RHM, one or more other materials. Such materials can be compounds which influence the nature or the rate of the crosslinking reaction, and which can be in latent form, e.g. catalysts, polymerization inhibitors, and polymerization initiators. Such materials can also be added at a later stage, prior to the crosslinking reaction. Initiators may be present, for example, in amount 0.1 to 5%, and include organic derivatives of hydrogen peroxide such as para-t-butyl peroxybenzoate and 1,1-di-t-amyl peroxycyclohexane. Such other materials can also be, for example, materials which affect the physical properties of the curable resin or of the cured resin, for example fillers, LPAs, thickening agents, mold release agents, viscosity reducers, wetting agents and colorants. Such other materials can also be coadditives as disclosed in the pending U.S. applications referred to above. Suitable fillers include inorganic and organic materials, including fibrous fillers such as glass, Kevlar or carbon fibers, hollow glass microspheres, hollow polymeric microspheres, calcium carbonate and alumina trihydrate. The amount of filler, if present, may be 10 to 70%, for example 15 to 35%, and may be such that the curable composition has the consistency of a paste or is even a self-supporting solid. The amount of mold release agent, if present, may be 1 to 4%; mold release agents include calcium and zinc sterates. The amount of colorant, if present, may be 0.5 to 4%. The amount of thickener, if present, may be 0.1 to 3%; thickeners include magnesium oxide and calcium hydroxide.
The invention is particularly useful in the preparation of molded products of a cured resin derived from an unsaturated polyester (optionally with styrene), a vinyl ester, an acrylic resin, or an epoxy resin. The term xe2x80x9cunsaturated polyesterxe2x80x9d is used in this specification in its conventional sense to mean a polymer in which the monomer units are linked to each other through an ester group and which contains carbonxe2x80x94carbon double bonds that are capable of undergoing further polymerization. The term xe2x80x9cvinyl esterxe2x80x9d is likewise used in its conventional sense to denote a subclass of the unsaturated polyesters, namely those which contain vinyl groups, in particular polymers made by addition reactions involving polyepoxides and unsaturated acids. In order to prepare crosslinked thermoset resins from these polymers, they are generally dissolved in a monomer such as styrene and then copolymerized with the monomer. Other precursors include cyanate esters, isocyanurates, imides, bismaleimides, ureas, cyanoacrylates, epoxy novolac, resins, polyurethanes and phenolic resins.
The invention is particularly useful for reducing the tack at ambient temperatures of a curable resin composition which contains a relatively large amount of filler and/or other ingredient (e.g. 20 to 50% of glass fibers, or of hollow glass or polymeric microspheres), so that the composition has the consistency of a paste, or even is a self-supporting solid. Applications of this type include SMCs, particularly SMCs based on a mixture of an unsaturated polyester and styrene or another unsaturated comonomer. The invention is also useful for improving the moldability of curable compositions at temperatures above Tp. The RHM may also improve the release properties of the cured resin from a mold, and/or reduce the tendency of cured resin articles to stick to each other. Thus the invention is particularly useful in the preparation of dry film resists (DFRs) and flexographic print plates, as described for example in The Multilayer Printed Circuit Board, J A Scarlett (1985), and the Printed Circuit Handbook, Clyde F. Coombs (1988).
For further details of suitable precursors of the cured resin and other ingredients, reference should be made to the documents referred to above and incorporated herein by reference, and to
(a) Handbook of Epoxy Resins by Henry Lee and Kris Neville; 1967; McGraw-Hill Inc.
(b) Epoxy Resins, Chemistry and Technology 2nd Edition, edited by Clayton A. May; 1988; Marcel Dekker, Inc.
(c) Polyurethanes, Chemistry, Technology and Applications by Z. Wirpsza; 1993; Ellis Norwood Ltd.
(d) The ICI Polyurethanes Book by George Woods; 1987; John Wiley and Sons, Inc.
(e) Structural Adhesives, Chemistry and Technology, edited by S. R. Hartshort; 1986; Plenum Press
(f) Test Methods for Epoxy Compounds; published by the Society of the Plastics Industry, Inc., Epoxy Resin Formlations Division
(g) Thermal Characterization of Polymeric Materials, edited by Edith A. Turi; 1981; Academic Press, Inc., and
(h) Reaction Polymers, edited by Wilson F. Gum et al, Hanser Publishing.
The disclosure of each of documents (a) to (h) above is incorporated herein by reference.
The crystalline polymer in the RHM (the term xe2x80x9ccrystalline polymerxe2x80x9d being used to include a crystalline polymeric moiety which is chemically bound to a non-crystalline moiety) can be a single polymer or a mixture of polymers, and the polymer can be a homopolymer, or a copolymer of two or more comonomers, including random copolymers, graft copolymers, block copolymers and thermoplastic elastomers. Preferably at least part of the polymeric moiety is derived from a side chain crystallizable (SCC) polymer. The SCC polymer may for example be derived from one or more acrylic, methacrylic, olefinic, epoxy, vinyl, ester-containing, amide-containing or ether-containing monomers. The molecular weight of an SCC polymer is relatively unimportant to its Tp, but is generally an important factor in determining the Tp of other polymers. The preferred SCC polymeric moieties are described in detail below. However, the invention includes the use of other crystalline polymers having the desired properties. Such other polymers include for example polymers in which the crystallinity results exclusively or predominantly from the polymer backbone, e.g. polymers of a-olefins containing 2 to 12, preferably 2 to 8, carbon atoms, e.g. polymers of monomers having the formula CH2xe2x95x90CHR, where R is hydrogen, methyl, propyl, butyl, pentyl, 4-methylpentyl, hexyl or heptyl, as well as other polymers such as polyesters, polyamides, and polyalkylene oxides, for example polytetrahydrofuran.
It is important that the polymeric moiety should melt over a relatively small temeprature range. The closer Tp is to room temperature, the more rapid the transition should preferably be. Thus Tpxe2x88x92To is preferably less than Tp0.7, particularly less than Tp0.6, To and Tp being in xc2x0 C. Tp can vary widely, depending on the conditions under which the composition is to be stored, shaped and cured. Thus in general, Tp is preferably at least 25xc2x0 C., for example 25 to 120xc2x0 C., preferably 35 to 70xc2x0 C. Tpxe2x88x92To is preferably less than 10xc2x0 C., particularly less than 8xc2x0 C., more particularly less than 6xc2x0 C., especially less than 4xc2x0 C.
SCC polymers which can be used in this invention include known SCC polymers, e.g. polymers derived from one or more monomers such as substituted and unsubstituted acrylates, methacrylates, fluoroacrylates, vinyl esters, acrylamides, methacrylamides, maleimides, xcex1-olefins, p-alkyl styrenes, alkylvinyl ethers, alkylethylene oxides, alkyl phosphazenes and amino acids; polyisocyanates; polyurethanes; polysilanes; polysiloxanes; and polyethers; all of such polymers containing long chain crystallizable groups. Suitable SCC polymers are described for example in J. Poly. Sci. 60, 19 (1962), J. Poly. Sci, (Polymer Chemistry) 7, 3053 (1969), 9, 1835, 3349, 3351, 3367, 10, 1657, 3347, 18, 2197, 19, 1871, J. Poly. Sci, Poly-Physics Ed 18 2197 (1980), J. Poly. Sci, Macromol. Rev, 8, 117 (1974), Macromolecules 12, 94 (1979), 13, 12, 15, 18, 2141, 19, 611, JACS 75, 3326 (1953), 76; 6280, Polymer J 17, 991 (1985); and Poly. Sci USSR 21, 241 (1979) and in the commonly assigned U.S. patent applications referred to above and their PCT equivalents.
Preferred SCC polymers comprise side chains comprising linear polymethylene moieties containing 12 to 50, especially 14 to 22, carbon atoms, or linear perfluorinated or substantially perfluorinated polymethylene moieties containing 6 to 50 carbon atoms. Polymers containing such side chains can be prepared by polymerizing one or more corresponding linear aliphatic acrylates or methacrylates, or equivalent monomers such as acrylamides or methacrylamides. A number of such monomers are available commercially, either as individual monomers or as mixtures of identified monomers, for example C12A, C14A, C16A, C18A, C22A, a mixture of C18A, C20A and C22A, a mixture of C26A to C40A, fluorinated C8A (AE800 from American Hoechst) and a mixture of fluorinated C8A, C10A and C12A (AE12 from American Hoechst). The polymers can optionally also contain units derived from one or more other comonomers preferably selected from other alkyl, hydroxyalkyl and alkoxyalkyl acrylates, methacrylates (e.g. glycidyl methacrylate), acrylamides and methacrylamides; acrylic and methacrylic acids; acrylamide; methacrylamide; maleic anhydride; and comonomers containing amine groups. Such other co-monomers are generally present in total amount less than 50%, particularly less than 35%, especially less than 25%, e.g. 0 to 15%. They may be added to modify the melting point or other physical properties of the polymers, in particular so as to make the crystalline polymer more compatible with the precursor(s) and/or the crosslinked resin, and thus promote the desired RHM activity. For example, in one embodiment, the crystalline polymer comprises (a) units derived from a monomer containing an n-alkyl group containing 12 to 50 carbon atoms and (b) at least 10% of units derived from a second monomer; and the matrix material comprises at least 10% of the second monomer or of units which are part of a polymer and are derived from the second monomer; preferably the crystalline polymer contains 10 to 50% of units derived from the second monomer, and the matrix material contains 20 to 50% of the second monomer, e.g. styrene. In another embodiment, the crystalline polymer contains 10 to 50% of units derived from the second monomer, and the matrix material comprises a polymer containing 10 to 70%, based on the matrix material, of units derived from the second monomer; preferably the matrix material comprises precursors for an acrylate polymer and the second monomer is an alkyl acrylate or an alkyl methacrylate in which the alkyl group contains 1 to 4 carbon atoms.

Side chain crystalline polymer as rheology modifier for crosslinked polymer


A micromechanical piezoresistive pressure sensor device having a sensor substrate, in which an essentially rectangular diaphragm region is provided; a piezoresistive resistance device having at least one piezoresistive resistor strip, which runs parallel to the longitudinal edges of the diaphragm device across the entire length of the diaphragm device and onto the surrounding sensor substrate; the piezoresistive resistor strip having a narrow center region and widened end regions and the widened end regions running across the short edges of the diaphragm device.

The current construction of micromechanical piezoresistive pressure sensors for use in the automotive field provides for four piezoresistive resistor strips, which in each case are located at the center of the edge of a square diaphragm and are interconnected to form a Wheatstone bridge.
From U.S. Pat. Nos. 5,485,753 and 5,714,690, rectangular diaphragms are known, on which the piezoresistive resistor strips run parallel to the long edge. From K. H.-L. Chau et al., "HIGH-STRESS AND OVERRANGE BEHAVIOUR OF SEALED-CAVITY POLYSILICON PRESSURE SENSORS", IEEE Solidstate Sensor and Actuator Workshop, Jun. 4, 1990, pages 181 through 183, rectangular diaphragms having an aspect ratio greater than 3:1 are known.
FIG. 4 shows a micromechanical piezoresistive pressure sensor device known from U.S. Pat. No. 5,714,690.
In FIG. 4, reference character 30 designates a silicon sensor substrate having a diaphragm region 36. Diaphragm region 36, for example, is a region of substrate 30 that has been thinned from the back using an anisotropic etching method.
Diaphragm region 36 has a rectangular shape with a high aspect ratio, which means that the long sides of the diaphragm edge 39 are significantly longer than the narrow sides. Piezoresistive resistor strips 35a, 35b run in the central region 91 of diaphragm region 36 parallel to the latter's long sides, that is, strip 35a near the longitudinal edge and strip 35b at the longitudinal center line 4a. Thus strip 35a is located in a region of high tensile stress and strip 35b in the region of the highest compressive stress. At their ends, strips 35a, 35b are bent and lead into bonding surfaces 31a, 32a or 31b, 32b, which are provided on the surface of substrate 30.
In the case of a rectangular diaphragm region 36, the surface requirement for achieving a specified sensitivity is greater than that in the case of a square diaphragm. In the case of a rectangular diaphragm, however, the resistance of the strip, which runs parallel to the long edge at the center of the diaphragm, is in quantitative terms approx. 50% lower. The center resistance displays over pressure a higher nonlinearity than the edge resistance.
The square diaphragm has the advantage that, although the piezoresistive resistor strip pairs differ in terms of their sign, they are almost identical in quantitative terms and do not differ in their nonlinear behavior.
The mentioned problem is likely responsible for the fact that rectangular diaphragms so far are not finding a significant use in commercial micromechanical piezoresistive pressure sensor devices.
In U.S. Pat. No. 5,714,690, moreover, piezoresistive resistor strips 35a, 35b run perpendicularly across the longitudinal edge of diaphragm region 36. This immediately reduces the sensitivity since the direction of the current is here turned by 90° with respect to the region relevant for the measurement and is thus running parallel to the mechanical stress.

Micromechanical piezoresistive pressure sensor device


A Content-Centric Network and a method of performing routing between domains therefore are provided. The method includes identifying a route from an anchor hub in a first domain to one or more hubs in the first domain, the anchor hub being configured to store routing information between a first border hub of the hubs in the first domain and a second border hub in a second domain, detecting, by each of the hubs in the first domain, a neighboring hub based on a sync direction corresponding to the identified route, and sharing the routing information with the neighboring hub, the sharing of the routing information including performing a sync operation between the neighboring hub and each of the hubs in the first domain.

1. Field
The following description relates to a Content-Centric Network and a method of performing routing between domains therefor.
2. Description of Related Art
In a Content-Centric Network (CCN), packets are classified into content request packets and content transfer packets. A content request packet contains a name of content that is requested. A content transfer packet contains the requested content, a name of the requested content, and the like.
For example, when a content request packet is received by networking equipment, the networking equipment may use the name of the content that is requested in a header to search storage of the networking equipment for the content that is requested by the content request packet. In this example, when the requested content is found, the networking equipment may transfer the requested content to a requester. Accordingly, in the CCN, a predetermined node in a route to an original owner of the requested content may provide the requested content when the requested content is stored in storage of the predetermined node. On the other hand, an Internet Protocol (IP)-based Internet requires requested content to be received directly from the original owner of the requested content. Since an average length of a transmission route is reduced, overall usage of a network may be reduced.
The CCN may search for neighboring content through flooding of a content request packet, namely an interest. The flooding is a representative scheme of damaging scalability. Accordingly, there is a desire for a routing method that may set a small-scale community or an area that includes a predetermined number of routers or terminals (e.g., several tens to hundreds of routers or terminals) to be a basic set (e.g., a domain), and connects domains on a large scale.

Content-centric network and method of performing routing between domains therefor


An electrical connector includes a conductive shell with electrical terminals, an insulator, conductive switch contacts, and an electrical circuit element constructed to engage the shell and the switch contact. The shell and the insulator interlock for ease of assembly.

A connector is known from U.S. Pat. No. 4,884,982 and comprises electrical capacitor elements inset within an outer profile of the connector and a conductive clip holding the capacitor elements in pressure contact with a conductive shell of the connector. This known connector includes an electrical contact with an electrical receptacle portion within the shell of the connector.
Another known connector, disclosed in U.S. application Ser. No. 07/519,968, filed May 7, 1990, now U.S. Pat. No. 5,030,122 comprises electrical switch contacts within a conductive shell of the connector.
In the known connectors described above, the component parts are not interlocked. Consequently, a manufacturing operation is required to fix in place the component parts. For the connector known from U.S. Pat. No. 4,884,982, a thin flange is flared outwardly. For the connector known from the '968 U.S. patent application, the shell is built from bipartite sections.
Other examples of known electrical connectors are illustrated in U.S. Pat. Nos. 5,073,123 and 5,030,122 by Birch et al. wherein each patent discloses a bipartite dielectric support surrounded by conductive shells of two electrical connectors. The dielectric support receives first and second switch contacts. The first switch contact has a curved contact while the second switch contact is straight.
U.S. Pat. No. 4,906,208 by Nakamura et al. discloses an electrical connector comprising a shielding shell and an insulating housing with female contacts. The insulating housing has latch bosses to be received by latch apertures located on the shielding shell so that the insulating housing and shielding shell are locked.
Another patent disclosing a contact element is U.S. Pat. No. 4,804,339 by Cohen which discloses an insulative body assembled in a conductive shell, two pairs of contacts located inside of the insulative body, and each pair of contacts comprises a straight contact and a curved contact which engage each other until the connector assemblies are mated together.
Various alternative connecting schemes between a conductor and insulator are disclosed in U.S. Pat. Nos. 4,722,022, 4,666,231, and 4,659,162. U.S. Pat. No. 4,722,022 by Myers et al. discloses an outer insulative enclosure and conductive shields enclosing a line terminator. The conductive shields have gripping means which engage the side walls of the outer insulative enclosure to enhance the friction fit.
U.S. Pat. No. 4,666,231 by Sheesley et al. discloses a shell assembled in a front end of an insulative body.
U.S. Pat. No. 4,659,162 by Cartesse discloses a connector casing which receives insulating blocks which have receiving sockets. Clips are used to lock the blocks into the casing.
It is an object of the present invention to provide an improved interlocking structure between an insulator and a conducting shell of a connector to provide for ease of manufacture and assembly.
Another object of the present invention is to provide an improved contact device of a connector with a preloaded spring force to assure there is sufficient contact pressure against a pin of a complementary connector which is inserted in the connector. Thus, the contact device does not require a large deflection by the inserted pin to produce the desired contact pressure.
Another object of the present invention is to provide a contact device with lower frictional resistance against initial engagement during insertion of a pin of a complementary connector.
A further object of the present invention is to provide an improved contact device which resists stubbing with a pin of a complementary connector.
These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description, taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.

Electrical connector with interlocked components


A communication access protocol improves the accessibility of devices operating on an asynchronous network (100), while supporting reduced power consumption. The network (100) includes a mediation device (130) for facilitating communications among network devices. Generally, each network device periodically transmits beacon signals to advertise its presence, and listens for communication signals targeted at the network device (532, 534). A device initiating communication with another operates in one of at least two operating modes in order to establish communications (536, 537, 538). In one mode, the initiating device communicates with the mediation device in order to derive timing information for the other device (537). In another mode, the initiating device listens to receive beacon signals directly from the target device in order to synchronize communications with the device (538). The selection of one of the two operating modes depends on a control parameter established for the initiating device, which in one embodiment is dependent on the urgency of communication, a maximum number of retries for using the mediation device, or the like.

Conventional wireless networks often utilize a synchronous communication protocol that enables network devices to communicate with each other using known or derived timing information. Such network devices are able to operate in a power efficient manner by communicating with each other using the timing information, and by otherwise operating in a sleep or other reduced power consumption mode. However, networks designed to operate using a synchronous communication protocol typically require access to centralized timing information, such as would be provided by infrastructure equipment, which adds cost and complexity.
Wireless networks that utilize an asynchronous communication protocol provide an alternative to the above-mentioned conventional synchronous wireless networks. Such networks are configured to enable associated network devices to communicate directly with one another through, for example, an ad hoc network. Because the network devices communicate directly with one another, the devices need not synchronize with a centralized timing system. Asynchronous transmission is generally used when low power devices make up the network. These low power devices can use a low communication duty cycle frame structure in order to minimize the amount of power used while not actively communicating with other network devices, but the use of a low communication duty cycle frame structure often implies that device availability is reduced. In wireless communication networks, a fundamental challenge is maintaining high availability communications while using low power wireless communication devices.
To lower power consumption, it is important to reduce the average communication duty cycle of all the devices in the network. The average communication duty cycle refers to the fraction of time that the wireless device is able to send and receive messages. For a given asynchronous network, the average communication duty cycle may be set so low that the infrequent communications between a transmitter and a target receiver become a problem. For example, a device A may attempt to contact another device B, but device B may be not be able to receive messages due to its low average communication duty cycle. This may prevent device A from establishing contact. A configuration change that increases the duty cycle of device A and/or device B would ordinarily result in an increase in power consumption.
It is desirable to provide for a communication protocol that improves the accessibility of devices operating on asynchronous networks without the traditional infrastructure that typically provides synchronization. Accordingly, a new access protocol is needed.

System and method for asynchronous communications employing direct and indirect access protocols


A polyetherimide manufactured by reaction of an alkali metal salt of a dihydroxy aromatic compound of the formulaMO—Z—OMwherein M is an alkali metal salt and Z is an aromatic C6-24 monocyclic or polycyclic moiety optionally substituted with 1 to 6 C1-8 alkyl groups, 1 to 8 halogen atoms, or a combination thereof,                with a bis(halophthalimide) composition comprising, based on the weight of the bis(halophthalimide) composition,                    from more than 45 to less than 75 weight percent of a 3,3′-bis(halophthalimide) of the formula

This disclosure relates to polyetherimides and compositions containing the polyetherimides, as well as their method of manufacture and articles formed from the polyetherimide compositions.
Polyetherimides ("PEIs") are amorphous, transparent, high performance polymers having a glass transition temperature ("Tg") of greater than 180° C. PEIs further have high strength, heat resistance, and modulus, and broad chemical resistance, and so are widely used in applications as diverse as automotive, telecommunication, aerospace, electrical/electronics, transportation, and healthcare.
Polyetherimides can be manufactured commercially by a "halo-displacement process." As shown in FIG. 1, a halogen-substituted anhydride is reacted with a diamine to form a bishalophthalimide. The bishalophthalimide is then reacted with a metal salt of a dihydroxy compound. Despite extensive investigation into the manufacture of polyetherimides produced using the halo-displacement process, there nonetheless remains a need for further improvement. For example, some polyetherimides are currently manufactured using a 95:5 ratio of the 4-isomer to the 3-isomer of the halophthalic anhydride, which yields a product having excellent ductility. Increasing the relative ratio of the 3-isomer can enhance flow and Tg of the polyetherimides, but ratios of 90:10 or below results in a dramatic loss of ductility.
There accordingly remains a need in the art for polyetherimides and methods for the manufacture of polyetherimides having improved properties, in particular polyetherimides having improved Tg and flow, without significantly adversely affecting ductility. It would be a further advantage if such improvements were obtained without significantly adversely affecting other desirable properties of the polyetherimides, for example one or more of heat deflection temperature, Vicat, and high tensile strength at yield.

Polyetherimides, methods of manufacture, and articles formed therefrom

Abstract: less than 10 weight percent of a 3,4′-bis(halophthalimide) of the formula

Abstract: and                    from more than 45 to less than 75 weight percent of a (4,4′-bis(halophthalimide) of the formula


An assembly for manual control of an HSTA for controlling the position of a moveable surface, the assembly comprising a user-operated manual control element (1′) e.g. a trim wheel in the cockpit, a first motor and a first resolver connected to the manual control element and a second motor and a second resolver arranged to communicate with the first motor and the first resolver and to cause corresponding movement of the actuator, in use.

HSTAs, also known as trimmable horizontal stabilizer actuators (THSAs), are actuators that move tail surfaces to trim an aircraft. The actuator must have a very high structural integrity to move a large surface in response to trim signals from the pilot or autopilot. Severe working environment, workloads and criticality of THSA function makes the system's engineering and manufacturing very complex.
Conventionally, in aircraft, the actuators are hydraulic actuators, but more recently it has become more common to use electromechanical stabilizer actuators, particularly for larger aircraft. Similar actuators are used to position other moveable surfaces in aircraft such as wings, slats, flaps and rudders.
On some types of aircraft, conventional HSTAs are commanded by, usually, three independent motors connected to the flight control computer (FCC) which drives a hydraulic control valve to control the position of the movable surfaces. Position feedback is provided to enable more accurate surface position control. Such systems are known from, e.g. U.S. Pat. Nos. 4,840,031 and 6,439,512.
Many aircraft are now also provided with a manual control for the HSTA, as a back-up to the automatic control. Using the manual control, the pilot can directly drive the actuator from the cockpit by means of a manual handle or trim wheel. The trim wheel is usually installed in the cockpit central panel or elsewhere in the cockpit easily accessible to the pilot. The pilot can select to control the HSTA manually and thus override the FCC. A back-up flight control system is taught, for example, in U.S. Pat. No. 8,935,015. Such HSTA architecture is used, for example, in some fly-by-wire programs.
Although the manual back-up control has safety-related advantages—i.e. in the case of failure of the automatic control, the manual control is also particularly useful in setting the horizontal trim to the best position during take-off. The pilot takes the actual position of the trim wheel in front of him, that he is turning, as an indication of the position of the trim.
The linkage between the manual trim wheel and the input to the HSTA is, however, a complex system made of cables and pulleys etc. The system is quite bulky and heavy and maintenance is also time intensive, difficult and expensive.
An HSTA assembly is desired that addresses these issues.

Horizontal stabilizer trim actuator assembly


The present invention relates to a frustoconical- or truncated pyramid-shaped support structure for wind-driven power generators which is formed by several precast concrete panels having the same dimensions, without horizontal joints between panels, which allows obtaining different section widths by means of a platform-guide that can be adjusted to one of said panels.

Today there are different support structure systems for wind-driven power generators depending on the type of material used for manufacture, such as wood, steel or concrete.
Wood support structures have a height limitation of about 20 m.
The most commonly used generator support towers are metal towers with either a lattice structure or a hollow frustoconical or cylindrical shape. Such towers has a series of problems such as the need for constant maintenance with treatments protecting them from rust and the short operative duration thereof due to material wear caused by fatigue (as a result of the constant tension and compression cycles caused by wind force that the towers must withstand).
Furthermore, they have the added problem that they are only usable both technically and economically for heights less than 100 m due to the high cost involved in forming sections greater than 4.5 meters in diameter at the base, because they could not be transported by road since they would not pass under the number of bridges from the factory to the wind farm.
Therefore, the range of use of such metal structures ranges from 20 m to 100 m.
Today there are different designs of support structures for wind-driven power generators made of reinforced concrete, however none of them can compete with the aforementioned metal structures in terms of pricing and ease of assembly. Such structures have the drawback of incorporating several horizontal joints between the panels forming it, requiring very expensive molds for manufacture and complex attachments of all the panels to one another based on on-site tensioning cables.
Due to the high cost of concrete support structures, they are used for heights that cannot be achieved at a reasonable or competitive cost using metal structures, i.e., 100 m and higher.
The concrete support structure for wind-driven power generators object of this invention has a series of improvements over the existing structures which allow competing with and economically improving the solution of metal structures in the range of heights from 20 to 100 m. Likewise, by means of incorporating a simple transition part it allows obtaining greater heights.
The applicant is aware of the existence of other support structures such as the case of the patent with publication number EP1474579 which discloses a structure with several segments in height, all the horizontal joints generated having to be resolved, a subsequent post-tensioning being performed on-site by attaching all the panels with cables along the entire height thereof and always outside the concrete section, the panels being of a different geometry, whereby it is necessary to manufacture several molds.
U.S. Pat. No. 2,326,010 discloses a structure that is virtually identical to the preceding structure also formed by at least two segments in height with a decreasing section, whereby it needs more than one mold to precast the panels.
Patent number US2009307998 discloses an original support structure solution formed by a ring-shaped foundation associated with two concrete segments. The peculiar feature of this structure is that it has virtually the same width as the foundation where it rests, whereby the amount of concrete and steel of the structure increases considerably, with the subsequent additional cost.
The German company ENERCON markets and manufactures a structure formed by a number of concrete rings which are post-tensioned vertically on-site, attaching several ring segments at a time with cables. This solution greatly slows down assembly due to the large amount of horizontal attachments that must be resolved.
Patent number EP2420639 discloses a solution in which all the concrete elements together with the transition part are post-tensioned continuously on-site, anchoring the cables to the foundation. The post-tensioning cables are arranged outside the concrete section. This patent details the transition part, but does not define how the concrete segment is formed. The same author discloses a variant in patent number EP2402529, disclosing a corrugated concrete section that is very hard to produce.
The present invention discloses a frustoconical- or truncated pyramid-shaped support structure for wind-driven power generators which is formed by several precast concrete panels having identical dimensions, which has no horizontal joints between panels since they have the total height of said support structure. The panels are designed such that the vertical joints have a larger opening in the upper portion than in the lower portion to enable obtaining different section widths in the upper portion of this structure.
The improvements of the present invention over the existing concrete structures are:                The absence of horizontal joints with the subsequent assembly time and cost savings.        Different section widths can be obtained in the upper portion to enable adjustment to different measurements of turbines from different manufacturers.        All the panels have the same dimensions, whereby saving in investing in molds. This improvement along with the foregoing improvement allows using a single mold for all kinds of heights and widths.        On-site post-tensioning along the entire height for anchoring to the foundation is not necessary, which reduces assembly times and costs.        Post-tensioning cables are in no case arranged outside the concrete section which drastically reduces maintenance operations with respect to solutions that do contemplate said outer cables.

Support structure for wind-driven power generators and mold for obtaining such structures


A memory device has a pair of conductive layers and an organic compound having a liquid crystal property that is interposed between the pair of conductive layers. Data is recorded in the memory device by applying a first voltage to the pair of conductive layers and heating the organic compound, to cause a phase change of the organic compound from a first phase to a second phase.

1. Field of the Invention
The present invention relates to a memory device and a semiconductor device equipped with the memory device.
2. Description of the Related Art
In recent years, a semiconductor device having a plurality of circuits integrated over an insulated surface and various functions has been developed. Further, development of a semiconductor device capable of wireless data transmission/reception by providing an antenna has been advanced. Such a semiconductor device is referred to as a wireless chip (also referred to as an ID tag, an IC tag, an IC chip, an RF (Radio Frequency) tag, a wireless tag, an electronic tag, or an RFID (Radio Frequency Identification) tag), and is already introduced to a part of the market.
Many of these semiconductor devices that have already been put into practical use include a circuit using a semiconductor substrate such as a Si substrate (also referred to as an IC (Integrated Circuit) chip) and an antenna, and the IC chip includes a memory circuit (also referred to as a memory), a control circuit and the like. In particular, by providing a memory circuit which can store much data, a high-value-added semiconductor device providing higher performance can be provided. In addition, there are demands that such semiconductor devices be manufactured at low cost, and in recent years, an organic TFT, an organic memory and the like using an organic compound for a control circuit, a memory circuit and the like have been actively developed (Reference 1: Japanese Patent Application Laid-Open No. 2002-26277).

Semiconductor Energy Laboratory Co., Ltd.


In the white level detection circuit for an optical image reader, for a low value portion in an image, the white level signal corresponding to an image signal of a high value background portion which precedes to the low value portion is held steady. Accordingly, even if the low value image portion has a long duration, the white level signal may be kept at a proper value for the image signal corresponding to the low value image signal. For the high value background portion, the white level signal that immediately follows a variation of the image signal can be obtained. Therefore, a proper white level signal can be generated for the background portion. Various processing applied to the image signal on the basis of the white level signal may be performed in a satisfactory manner. As a consequence, the read performance of the optical image reader may be remarkably improved.

1. Field of the Invention
The present invention relates to a white level detection circuit for an optical image reader, such as an optical character reader (OCR), a bar code reader or an image scanner.
2. Description of the Prior Art
An optical image reader is known which optically reads an image by using opto-electric transducing elements, such as image sensors and photo diodes, and processes image data generated by those elements. An optical character reader (OCR) and a bar code reader are examples of this type of optical image reader. An image signal output from an image sensor is converted into binary image data. The binary image data is processed for recognizing characters and bar codes. It is common practice that image data is processed on the basis of a white level (signal level) corresponding to a background portion of high value (e.g., white color) in the image.
The white level may not be uniform over the image for various reasons, such as nonuniformity of an illuminating light source, deterioration of the efficiency of an imaging lens around the fringe of the image by the cos.sup.4 rule, the quality of paper bearing the image data and dirt on the surface of the paper. To accurately reproduce an image, it is necessary to accurately know the white level, which varies with location, on the image.
A basic construction of a white level detection circuit thus far employed in a bar code reader, for example, is shown in FIG. 4. The white level detection circuit is essentially a peak hold circuit. An output signal of an image sensor constituting an input image signal is applied through a buffer amplifier 1 and a diode 2 to a capacitor 3. The capacitor 3 is charged with the image signal, and discharged through a resistor 4. A potential appearing at the terminal of the capacitor 3 provides a white level signal, by way of a buffer amplifier 5.
FIG. 5 is a diagram showing a waveform useful in explaining the operation of the white level detection circuit of FIG. 4. The image signal is represented by a curve L1, and the white level signal by a curve L2. Consider the simple case of a black bar code formed on white paper. A white period W corresponds to a white portion in the image, and a black period B, to a black portion (i.e., black bar). A period TB indicates a blank period of the image sensor. When the image signal increases, the capacitor 3 is charged through the diode 2. When the image signal decreases, the capacitor 3 is discharged at a preset time constant, through the resistor 4. When a point being read changes from black to white, the image signal sharply rises and capacitor 3 charges through the diode 2. As a result, during the white period W, a white level signal, equal to the image signal, is output. When the point being read changes from black to white, the image signal sharply falls. Capacitor 3 discharges thereby maintaining the image signal substantially equal to the value during the previous white period W. Changes in the white level, which are due to changes of value or brightness in the white portion on the paper, are subtle. Accordingly, when the white level on the paper falls, the white level signal accurately follows the fall of the white level.
In the prior art, if a relatively long black portion exists, a long black period BL appears, as shown in FIG. 6. In this situation, the discharge of the capacitor 3 is completed by the end of the long black period BL. The white level signal (indicated by curve L2) falls to approach to the level of the image signal corresponding to the black portion as shown by reference character al. When the image signal is processed on the basis of such a white level signal, the black portion may be mistakenly recognized as the white portion. Although a mistake in recognition in which the white portion is recognized as the black portion or vice versa would never occur, the image signal of the black portion is increased in comparison to the white level signal, resulting in distortion of the recognized image. The distortion adversely affects the bar code discriminating processing, which includes binary processing.
One approach to solving this problem would be to sufficiently increase the discharge time-constant defined by the capacitor 3 and the resistor 4. This approach, however, may result in the failure of the white level signal to follow the natural fall of the white level on paper.
An arrangement which solved the problem of distorted images, is shown in FIG. 7. The arrangement includes a peak hold circuit 11 which has a variable discharge time-constant. The discharge time constant of the peak hold circuit 11 is selectively changed by a switch circuit 12 which selects a short time constant for the white portion and a long time constant for the black portion. The peak hold circuit 11 includes a capacitor, a diode for charging the capacitor, and a resistor for discharging the capacitor.
An image signal is applied to peak hold circuit 11 and to differentiation circuit 13. A derivative or differential coefficient produced by differentiation circuit 13 is compared to proper threshold levels TH1 and TH2 (TH1>0>TH2) in comparator circuit 14. The output signal of comparator circuit 14 is applied to flip-flop 15 as either set signal S or reset signal R,. thereby controlling switch circuit 12. Switch circuit 12 is rendered conductive or nonconductive depending on the state of flip-flop 15, thereby selecting the discharge time constant of the peak hold circuit 11 to be either short or long, respectively.
FIGS. 8(a) through 8(d) are diagrams showing waveforms useful in explaining the operation of the prior art circuit of FIG. 7. FIG. 8(a) shows an image signal waveform. FIG. 8(b) shows a waveform of the corresponding output signal of differentiation circuit 13. FIG. 8(c) shows a waveform of the resulting output signal of flip-flop 15. FIG. 8(d) shows the resultant output waveform of white level signal from peak hold circuit 11.
The image signal changes sharply at the start and end points of blank period TB and black period B. Pulse signals having polarity based on changes in the image signal, are output from differentiation circuit 13. When the signal is processed from blank period TB to white period W, and from black period B to white period W, the output signal of differentiation circuit 13 becomes a large positive signal, exceeding threshold level THl. As a result, the comparator circuit 14 produces a set signal S, setting the flip-flop 15, which in turn produces an output signal of logic "1". Consequently, switch circuit 12 selects a short discharge time constant of peak hold circuit 11. Accordingly, during period W, the white level signal accurately follows the change of the image signal.
When the signal is processed from white period W to either blank period TB or black period B, the output signal of differentiation circuit 13 is negative in polarity, falling below threshold value TH2. As a result, reset signal R is derived from comparator circuit 14, and resets the flip-flop 15 which in turn produces an output signal of logic "0". In response, switch circuit 12 selects a large discharge time-constant of the peak hold circuit 11. As a result, even if black period B is long, the white level signal can substantially maintain its value from the end of the previous white period. Accordingly, the black portion will not be mistaken for the white portion because the image distortion caused when the image signal in the black portion increases relative to the white level signal has been eliminated.
However, this prior art is not problem-free. When the white level on the paper surface falls during a long black period B, a proper white level signal cannot be obtained during the subsequent white period. This problem will be further described below with respect to FIGS. 9(a) and 9(b).
If, as shown in FIG. 9(a), the white level on the read surface increases by .DELTA.wl during the long black period BLl, peak hold circuit 11 immediately increases the white level signal which follows the image signal variation, during the white period W following the black period BLl. To the contrary, if as shown in FIG. 9(b), the white level on the read surface decreases by .DELTA.w2 during the long black period BL2, peak hold circuit 11 cannot immediately follow a variation of the decreased image signal during the white period W after the black period BL2. Rather, it slowly follows the variation of the decreased image signal at a time constant. As a result, during the white period W following black period BL2, a white level signal which is higher than the actual white level is output because image signal input during the white period W after the black period BL2 is lower than the white level signal retained in peak hold circuit 11 and cannot actively charge the capacitor in peak hold circuit 11. In other words, the circuit, out of necessity, waits until completion of the discharge of the capacitor with a time constant, in order that the white level signal changes after the image signal changes. Otherwise, when the white level signal is improper during the white period W, the white image is distorted.
A similar problem also arises when the white level of the image changes at the start point and the end point of the image scanning period. When the white level of the image signal at the start point of the scan period is higher than the white level at the end point by .DELTA.w, as shown in FIG. 10, the white level signal retained during blank period TB cannot immediately follow the image signal variation in the leading portion of the white period subsequent to blank period TB. As a result, as in the above case, the image in the white portion is distorted.
Accordingly, an object of the present invention is to provide a white level detection circuit for an optical image reader which produces a white level signal that accurately follows a variation of the white level on the surface, and produces a white level signal that allows for excellent processing of the image signal corresponding to the black portion.

White level detection circuit for an optical image reader


A semiconductor chip includes a substrate having a frontside and a backside coupled to a ground. The chip includes a circuit in the substrate at the frontside. A through silicon via (TSV) having a front-end, a back-end, and a lateral surface is included. The back-end and lateral surface of the TSV are in the substrate, and the front-end of the TSV is substantially parallel to the frontside of the substrate. The chip also includes an antifuse material deposited between the back-end and lateral surface of the TSV and the substrate. The antifuse material insulates the TSV from the substrate. The chip includes a ground layer insulated from the substrate and coupled with the TSV and the circuit. The ground layer conducts a program voltage to the TSV to cause a portion of the antifuse material to migrate away from the TSV, thereby connecting the circuit to the ground.

Integrated circuits (ICs) have become ubiquitous. Cell phones, PDAs, cameras, medical devices, laptops, and many other devices include ICs. A typical IC includes several types of semiconductor devices, such as transistors. In modern ICs, transistors may be used to implement logic or memory functions. Typically, ICs have been planar in design. Planar semiconductor chip designs limit the amount of circuitry that may be placed on a single IC die.
To overcome some of the limitations of planar ICs, designers began stacking chips vertically to form three-dimensional designs. A three-dimensional (3D) IC, therefore, is a semiconductor assembly in which two or more planar layers of active electronic components are integrated both vertically and horizontally into a single device. These three-dimensional structures increase the density of active circuits.

This patent is subject to a terminal disclaimer.

Semiconductor chip with power gating through silicon vias

International Business Machines Corporation


A multi-cloud service system establishes tunnels and network overlays across multiple CSPs while meeting a criterion for a latency threshold. The system conducts a latency benchmarking evaluation across each cloud region for multiple CSPs and based on the latency bench marking evaluation results, the system may identify a group of cloud regions that satisfy a criterion such as predetermined maximum latency threshold or geographical restriction. The system may provision the group of cloud regions by provisioning a tunnel between nodes of the multiple CSPs. The system further establishes an overlay network on top of the tunnel by encapsulating packets using encapsulation end point such as VTEP (VXLAN tunnel end point) over VXLAN (Virtual Extension Local Area Network), which may help to ensure reliable transmission of packets from pod to pod. The system may inject user data into each node to initiate operations across the provisioned nodes using injected user data.

Many CSPs exist today that offer cloud resources as a service and organizations often deploy applications within single cloud provider. The term CSP, or cloud service provider, may refer to an enterprise that provides Infrastructure as a Service such as compute, storage and network. CSPs may also provide higher-order services such as database, messaging, search, Machine Learning, CDN, data processing, etc. Organizations may face technical limitations when attempting to deploy applications across two or more different cloud service providers. For example, latency may be introduced for a variety of reasons, such as physical data center location, where disparate cloud regions are physically too far away from each other for low-latency distributed computing workloads. Databases required to adhere to standards, such as a requirement to have atomicity, consistency, isolation, durability (ACID) properties may not function, or may function sub-optimally, where latency exceeds a particular operating threshold. Moreover, addresses (e.g., source addresses) of containers within container groups located at one CSP may not be recognized using protocols of another CSP, thus causing dropped packets and lost data, also resulting in suboptimal or insufficient performance.

Executing workloads across multiple cloud service providers


The present invention provides nucleic acids containing transcriptional units that encode CYP1B1 polypeptides or portions thereof, wherein the transcriptional units lack sequences found in the untranslated region (UTR) of naturally occurring forms of the CYP1B1 transcript. The nucleic acids of the invention lack translational repressor elements and thus provide for a system of enhanced translation of the CYP1B1 polypeptide or portions thereof. Also disclosed are methods of administering nucleic acids to a mammal and use in the treatment of proliferative disorders or cancer.

Cytochrome P450 constitutes a large gene family of enzymes that participate in the oxidative activation and/or deactivation of a wide range of xenobiotics, including many potential carcinogens and several anticancer drugs (Guengerich and Shimada (1991) Chem. Res. Toxicol. 4:931; Gonzalez and Gelboin (1994) Drug Metab. Rev. 26:165; Kivisto et al. (1995) Br. J. Clin. Pharmacol. 40:523).
The human CYP1 gene family, one of the major P450 families, consists of three individual forms classified into two sub-families. CYP1B1, a member of one sub-family, is 543 amino acids in length. It is structurally distinct from the two members of the CYP1A2 subfamily (Tang et al., J. Biol. Chem. (1996) 271:28324).
Studies of various types of cancer, including breast cancer, esophageal cancer and soft tissue sarcomas, have shown that there may be tumor-specific expression of a CYP1B1 form of P450 (see Murray et al. (1991) Br. J. Cancer 63:1021; Murray et al. (1993) J. Pathol. 171:49; Murray et al. (1994) Gut 35:599). Immunohistochemistry studies of CYP1B1 show a strong immunoreactivity for several different types of tumors (bladder, breast, colon, kidney, lung, esophagus, ovary, skin, stomach, uterus, bone and connective tissue, lymph node, brain, and testis) (see WO 97/12246, herein incorporated by reference).


A flywheel assembly (1) is provided for transmitting torque from a crankshaft (2) to a main drive shaft (3), and includes a first flywheel (4), a second flywheel (5) and a damper mechanism (6). The damper mechanism (6) is mechanically couples the second flywheel and the first flywheel together, however, the second flywheel is physically disposed between the first flywheel and the damper mechanism such that the damper mechanism may be replaced without removal of the second flywheel from the first flywheel.

A. Field of the Invention
The present invention relates to a flywheel assembly, and particularly a flywheel assembly provided with a damper mechanism between first and second flywheels.
B. Description of the Background Art
A flywheel is attached to a rear end of a crank shaft of an engine for dampening nonuniform crank shaft rotation during low-speed driving. The flywheel carries a ring gear for a starter and also includes means to support a clutch mechanism.
Such a flywheel assembly has been known where a flywheel is divided into first and second flywheels, and a damper mechanism is arranged between them. The damper mechanism includes elastic members which are arranged between the first and second flywheels, and are circumferentially compressed when the first and second flywheels rotate relative to each other. Some types of damper mechanisms include a friction generating mechanism which operates in parallel with the elastic members for dampening vibrations.
In the foregoing flywheel assembly, a power transmitting system can be divided into input and output sides with the elastic member of the damper mechanism therebetween. In such a system the moment of inertia of the input side and output side define a resonance frequency whereby, at a corresponding rotation speed of the engine, natural vibration occurs in the flywheel assembly. Ideally, the resonance frequency should be at a speed well below the idling speed of the engine.
In the flywheel assembly, the rotation speed of the engine passes through the resonance frequency, for example, in a speed range lower than 500 rpm when the engine starts or stops. At this time, an excessively large variation in torque may occur such that the damper mechanism may be damaged and undesirable noises and/or vibrations may occur. Under such conditions, an excessively large torque variation produce impact on the damper mechanism that may exceed a limit or stop torque of the damper mechanism.
In order to overcome the above problem, the damper mechanism may be formed a viscous resistance generating mechanism which utilizes a viscosity of fluid to generate a large resistance against an excessively large torque variation. Also, a lock mechanism may be used that locks the first and second flywheels together during at speeds close to the resonance frequency. The lock mechanism would also release the two flywheels from each other in a high-speed ranges.
Generally, the above described damper mechanism is arranged axially between the first and second flywheels. In a repair operation where a worn damper mechanism is replaced by a new damper mechanism, it is necessary to remove the second flywheel. However, removal of the second flywheel complicates the repair operation.


A method for fabricating a pixel structure using a laser ablation process is provided. This fabrication method forms a gate, a channel layer, a source, a drain, a passivation layer, and a pixel electrode sequentially by using a laser ablation process. Particularly, the fabrication method is not similar to a photolithography and etching process, so as to reduce the complicated photolithography and etching processes, such as spin coating process, soft-bake, hard-bake, exposure, developing, etching, and stripping. Therefore, the fabrication method simplifies the process and thus reduces the fabrication cost.

1. Field of the Invention
The present invention relates to a method for fabricating a pixel structure. More particularly, the present invention relates to a method for fabricating a pixel structure using a laser ablation process.
2. Description of Related Art
Displays are a communication interface between human and information. Currently, flat panel displays are the main trend in development. The flat panel displays may mainly have the following categories: organic electroluminescence display, plasma display, and thin film transistor liquid crystal display (TFT-LCD), in which TFT-LCD is the most widely used. In general, a TFT-LCD is constituted by a TFT array substrate, a color filter array substrate, and a liquid crystal layer. The TFT array substrate includes a plurality of scan lines, a plurality of data lines, and a plurality of pixel structures arranged in an array. Each pixel structure is electrically connected to the corresponding scan line and data line.
FIGS. 1A to 1G are schematic views of a conventional method for fabricating a pixel structure. Referring to FIG. 1A, first, a substrate 10 is provided, and a gate electrode 20 is formed on the substrate 10 using a first photolithography and etching process. Next, referring to FIG. 1B, a gate insulating layer 30 is formed on the substrate 10 to cover the gate electrode 20. Afterwards, referring to FIG. 1C, a channel layer 40 above the gate electrode 20 is formed on the gate insulating layer 30 using a second photolithography and etching process. In general, a material of the channel layer 40 is amorphous silicon. Then, referring to FIG. 1D, a source electrode 50 and a drain electrode 60 are formed on partial regions of the channel layer 40 and the gate insulating layer 30 using a third photolithography and etching process. Observed from FIG. 1D, the source electrode 50 and the drain electrode 60 respectively extend onto the gate insulating layer 30 from both sides of the channel layer 40, and expose a portion of the channel layer 40. Next, referring to FIG. 1E, a passivation layer 70 is formed on the substrate 10 to cover the gate insulating layer 30, the channel layer 40, the source electrode 50, and the drain electrode 60. Thereafter, referring to FIG. 1F, the passivation layer 70 is patterned by a fourth photolithography and etching process to form a contact hole H in the passivation layer 70. In FIG. 1F, the contact hole H in the passivation layer 70 exposes a portion of the drain electrode 60. Then, referring to FIG. 1G, a pixel electrode 80 is formed on the passivation layer 70 by a fifth photolithography and etching process, and observed from FIG. 1G, the pixel electrode 80 is electrically connected to the drain electrode 60 through the contact hole H. After the pixel electrode 80 is formed, the fabrication of the pixel structure 90 is completed.
In view of the above, the conventional pixel structure 90 is mainly fabricated by the five photolithography and etching processes. In other words, the pixel structure 90 must be fabricated with the five photo-masks of the different patterns.
The photo-masks are of high price, and each photolithography and etching process requires a photo-mask of a different pattern. If the photolithography and etching processes cannot be simplified, the fabrication cost of the conventional pixel structure cannot be reduced. Besides, with the increasing of the size of the TFT-LCD panel, the size of the photo-mask for fabricating the TFT array substrate is also enlarged, so the photo-mask of a larger size becomes more expensive, and the fabrication cost of the conventional pixel structure cannot be effectively lowered.


A machine has a network interface circuit to provide connectivity to networked machines. A processor is connected to the network interface circuit. A memory is connected to the processor and the network interface circuit. The memory stores cryptographically protected data, a data access policy and a steward group specifying individuals to administer the data access policy. The memory stores instructions executed by the processor to receive a request to access the cryptographically protected data. Authentication tokens from individuals in the steward group are collected. It is determined that the authentication tokens satisfy the data access policy to establish a data access state. A decrypted version of the cryptographically protected data is supplied to one or more of the networked machines to establish a transaction. The transaction is recorded with a distributed ledger associated with at least a subset of the networked machines.

The invention is disclosed in the context of the following definitions:
Blockchain: is a continuously growing list of records, called blocks, which are linked and secured using cryptography. Each block typically contains a cryptographic hash of the previous block, a timestamp and transaction data. By design, a blockchain is inherently resistant to modification of the data. It is an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way. For use as a distributed ledger, a blockchain is typically managed by a peer-to-peer network collectively adhering to a protocol for validating new blocks. Once recorded, the data in any given block cannot be altered retroactively without the alteration of all subsequent blocks, which requires collusion of the network majority. (Source: https://en.wikipedia.org/wiki/Blockchain)
Identity: "The characteristics determining who or what a person or thing is." (Source: Oxford Dictionary)
Protected Data: Comprises data or information being controlled within a Trusted Identity System. Examples may include: encryption keys, personal information, or other non-public data.
Protected Data Activation Token: A unique cryptographic token generated for and assigned to one specific Trusted Identity Steward. This token will enable the Trusted Identity Steward to submit a command (together with the token) to a computing device that is protected by the Trusted Identity System. Upon receipt and validation, the Trusted Identity System will invoke or activate the target's Protected Data Security Mechanism Activation Sequence. These are normally one-time-use tokens, but multi-use embodiments may exist.
Protected Data Security Mechanism: A cryptographic access control mechanism, or specification thereof, that controls access to Protected Data stored on data storage systems. This mechanism contains owner-defined access requirements, validates access requests and credentials, controls how access to Protected Data is granted, and controls events that occur to the Protected Data upon validated access control requests.
Protected Data Security Mechanism Activation Sequence: the steps specified as a part of the Protected Data Security Mechanism that are to be carried out when a Protected Data Activation Mechanism is activated. Sequences may include commands necessary to retrieve, transmit, copy, destroy, etc. the Protected Data. Additionally, if Protected Data is an executable computer file, then the Protected Data Activation Sequence may launch the specified executable computer file.
Trusted Identity: The basic end-user role within a Trusted Identity System. A Trusted Identity provides Protected Data to be controlled by a Trusted Identity Steward Group.
Trusted Identity Blockchain: A blockchain or immutable ledger to which are written the activities, agreements, events, identities, members, etc. that participate in the Trusted Identity System operations. This blockchain or ledger contains a verifiable history, timing, and sequence of Trusted Identity System events, which may be used for subsequent verification and validation activities. This blockchain or immutable ledger may be publicly accessible, or it may be private depending on the specific motivation and implementation of the Trusted Identity System. Although termed as 'blockchain' in the singular, some embodiments may employ multiple blockchains or protected storage services.
Trusted Identity Steward Group: A group of Trusted Identity Stewards collaborating to manage permissioned access (in compliance with the Protected Data Security Mechanism) to Protected Data.
Trusted Identity Steward Group Manager: The Trusted Identity Steward that created Trusted Identity Steward Group or the Trusted Identity Stewart that currently manages the Trusted Identity Steward Group (e.g., in the event that the manager had changed).
Trusted Identity Steward: One of the participants within a Trusted Identity Steward Group that helps control the granting of access to the Protected Data.
Trusted Identity Server: The server or set of servers implementing the server-side functionality (e.g., management, enrollment, etc.) of the Trusted Identity System.
Trusted Identity System: The system providing trusted and permissioned control of Protected Data of a Trusted Identity. The Trusted Identity System also ensures that the actions specified by the Protected Data Security Mechanism Activation Sequence are carried out upon invocation by the Trusted Identity Steward Group.
Trusted Identity System Application Software: The software (e.g., executable computer code, software development kit, application program interface, etc.) implementing methods whereby the end-user (and their computing devices) interacts with the Trusted Identity System, the Trusted Identity Stewards interact with the end-user's devices, the components managing the Protected Data, etc. This set of components is installed on the end-user's computing devices and operates within that environment within the end-user's control. The Trusted Identity System Application Software components may be installed on desktop operating systems (e.g., Windows®, MacOS®, Linux®, etc.), mobile environments (e.g., iOS®, Android®, etc.) and may operate on a wide range of hardware (e.g., desktop, mobile, embedded, 'internet of things', etc.)."
The laws of governments provide law enforcement organizations with the authority to investigate crimes and criminal activity in order to keep society safe from wrongdoing, criminals, terrorists, etc. Along with the investigative authority, the laws of governments also provide rules, regulations, and restrictions as to how governmental entities (e.g., law enforcement) may conduct investigations. The balance between the authority and limitations of the investigative processes is further defined by a nation's legal code.
As an example of the balance between legal authority and personal rights, the Fourth Amendment to the United States Constitution guarantees its citizens the right to be secure against unreasonable searches and seizures (e.g., by law enforcement) unless a legal and lawful warrant has been issued by a court of law. Such a warrant must outline the details of what is being sought and potentially seized. The checks and balances covering the warrant process stipulate that while warrants may be requested by law enforcement, they must also be approved by the governing court of law. Without the concurrence of the court of law, no search is authorized and may not be performed. The express intent of this process is to balance the desires of law enforcement with the rights of the people, which is that citizens must be free from searches of their persons, houses, papers, and effects unless probable causes has been demonstrated to the satisfaction of the court.
Upon issuance of a valid warrant in the physical world, law enforcement may open (or break through) the front door of a person's residence in order to search for and retrieve items authorized by the warrant. However, in the digital world where data is often protected by encryption, the issuance of a valid warrant alone does not provide law enforcement with the technical capability to decrypt and access data authorized by the warrant. Law enforcement agencies have complained that the use of encryption prohibits them from conducting legally authorized search activities. This has led law enforcement agencies to demand that encryption circumvention methods, such as key escrow, be mandated by law so that they can perform their investigative functions.
If an encrypted disk or data store is discovered during an investigation and the decryption key is not present, then law enforcement agencies will not be able to decrypt the encrypted data, which may hinder the investigation. Nevertheless, while the use of data encryption can hinder legal investigations, privacy rights groups are also observing that current methods of circumventing encryption (e.g., key escrow) upon obtaining a valid warrant could also be used illegally (e.g., without a warrant) or that they could be otherwise be abused by rogue or malicious employees. Privacy rights groups further argue that any encryption circumvention method that is inserted into the encryption process could also be illegally exploited by computer hackers to break into encrypted data systems or that such circumvention could be accidentally triggered by unforeseen computer errors. Since illegal abuse of systems by malicious employees, computer intrusions by hackers, and numerous computer errors have all been demonstrated, it is abundantly clear that personal data is not safe if contemporary encryption circumvention architectures are deployed.

Apparatus and method for enabling owner authorized monitored stewardship over protected data in computing devices


A photosensitive resin composition comprising (a) a compound obtained by reacting a polybasic acid anhydride with the phenolic hydroxyl groups of a novolac-type phenol resin, and (b) a 1,2-quinonediazide compound. The photosensitive resin composition, which comprises component (b) composed of a 1,2-quinonediazide compound in combination with a component (a) obtained by reacting a polybasic acid anhydride with the phenolic hydroxyl groups of a novolac-type phenol resin, exhibits sufficiently high photosensitivity, image contrast, resolution and adhesiveness.

Known methods for forming images used for patterning of semiconductor integrated circuits, liquid crystal display elements and printed circuit boards include methods that utilize positive photoresists comprising combinations of novolac-type phenol resins and 1,2-quinonediazide compounds.
Such a positive photoresist is alkali-insoluble at the unexposed sections and alkali-soluble at the exposed sections, so that the resist at the exposed sections is removed during alkali development. The 1,2-quinonediazide compound interacts with the novolac-type phenol resin at the unexposed sections during that time, acting as a dissolution preventer to render them alkali-insoluble. At the exposed sections, the 1,2-quinonediazide compound dissolves under the ultraviolet irradiation, undergoing Wolff rearrangement to produce an indene ketene. The indene ketene in addition reacts with water to produce an indenecarboxylic acid. This indenecarboxylic acid is acidic, while the residual novolac-type phenol resin is also weakly acidic because of its phenolic hydroxyl groups. The exposed sections are therefore rendered soluble in the strong alkaline aqueous solution of tetramethylammonium hydroxide.
However, development with strong alkaline aqueous solutions such as tetramethylammonium hydroxide can sometimes lead to peeling of the unexposed sections as well. When this occurs, the positive photoresist fails to exhibit adequate resolution. The use of strong alkaline aqueous solutions is also problematic from the viewpoint of safety and waste water treatment, as well as other environmental issues.
A demand therefore exists for a photosensitive resin composition that can be sufficiently developed even with weak alkaline aqueous solutions.
It has been attempted to meet this demand by enhancing the properties of photosensitive resin compositions. For example, there have been proposed photosensitive resin compositions containing compounds obtained by addition of acid anhydrides to reaction products of novolac-type epoxy compounds and unsaturated monobasic acids (see Patent documents 1-5). There have also been disclosed thermosetting/photocuring compositions containing a carboxyl group-containing, obtained by reacting an unsaturated monobasic acid with the reaction product of a novolac-type phenol resin and an alkylene oxide and reacting an acid anhydride with the resulting reaction product (see Patent document 6). Also proposed have been positive photosensitive resin compositions employing novolac-type phenol resins obtained by reaction between an acid anhydride and the alcoholic hydroxyl group of an alcoholic hydroxy group-containing novolac-type phenol resin (see Patent document 7).    [Patent document 1] Japanese Unexamined Patent Publication SHO No. 61-243869    [Patent document 2] Japanese Unexamined Patent Publication HEI No. 3-253093    [Patent document 3] Japanese Unexamined Patent Publication HEI No. 6-192387    [Patent document 4] Japanese Unexamined Patent Publication HEI No. 7-41716    [Patent document 5] Japanese Unexamined Patent Publication HEI No. 9-136942    [Patent document 6] International Patent Publication No. WO02/024774    [Patent document 7] Japanese Unexamined Patent Publication No. 2001-114853

Photosensitive resin composition and photosensitive element


A vehicle comprises at least one wheel supporting the vehicle and an engine. At least one axially rotating member operatively connects the engine with the wheel such that the wheel moves responsive to operation of the engine. At least one tag is disposed on the axially rotating member. At least one sensor is disposed on the vehicle so that the sensor can detect movement of the tag. A computer disposed on the vehicle is operatively connected with the sensor. The sensor sends a signal to the computer when the sensor detects movement of the tag. Means on the vehicle provides an operator of the vehicle with feedback indicative of movement of the vehicle.

Embodiments described herein generally relate to a vehicle with a movement sensor and a method of sensing movement of a vehicle.
A vehicle, such as a truck, a bus and the like, often includes a vehicle brake to limit movement of the vehicle. In some uses of a vehicle, it is desirable to limit movement of the vehicle to permit another operation. For example, it is desirable to limit movement of a bus while a passenger boards or departs from the bus. If the bus were to move while the passenger boards or departs from the bus, an unintended consequence, such as injury to the passenger, can occur. An operator of the bus can apply a vehicle brake to limit movement of the vehicle, e.g. bus, to reduce possibility of occurrence of an unintended consequence.
Sometimes, it is possible that, even when the vehicle brake is applied, movement of the vehicle is insufficiently limited allowing for occurrence of an unintended consequence. This could happen if, for example, the operator did not apply fully the vehicle brake, if terrain on which the vehicle is located is sloped or is slippery or any other condition that encourages movement of the vehicle. Accordingly, it is desirable to provide a vehicle with a system and method for alerting the operator to movement of the vehicle.

International Truck Intellectual Property Company, LLC