6678 results about "Polyimide" patented technology

Devices, systems and methods are provided for stimulation of tissues and structures within a body of a patient. In particular, implantable leads are provided which are comprised of a flexible circuit. Typically, the flexible circuit includes an array of conductors bonded to a thin dielectric film. Example dielectric films include polyimide, polyvinylidene fluoride (PVDF) or other biocompatible materials to name a few. Such leads are particularly suitable for stimulation of the spinal anatomy, more particularly suitable for stimulation of specific nerve anatomies, such as the dorsal root (optionally including the dorsal root ganglion).

The preparation process of phenolic hydroxyl group-containing polyimide powder includes the following steps: 1. reaction of phenolic hydroxyl group-containing aromatic diamine compound or its mixture with other diamine compound and aromatic binary anhydride in the molar ratio of 1 to 1 in strong polar non-protonic organic solvent under protection of nitrogen at 0-30 deg.c for 3-12 hr to obtain transparent ropy polyhydroxy amido acid solution; and 2. adding azeotropic dewatering agent in nitrogen atmosphere and heating to 120-160 deg.c to reflux, azeotropically dewater and imidize for 5-18 hr, cooling to room temperature, washing and vacuum drying to obtain phenolic hydroxyl group-containing polyimide powder. The industrial production process has environment friendship, simple operation, low cost and easy solvent recovery.

A non-volatile organic resistance memory device including a first electrode, a second electrode, and a polyimide layer interposed between the first and second electrodes. The polyimide layer has a thickness such that a resistance of the polyimide layer varies in accordance with a potential difference between the first and second electrodes.

The invention relates to a composite comprising a weight fraction of single-wall carbon nanotubes and at least one polar polymer wherein the composite has an electrical and/or thermal conductivity enhanced over that of the polymer alone. The invention also comprises a method for making this polymer composition. The present application provides composite compositions that, over a wide range of single-wall carbon nanotube loading, have electrical conductivities exceeding those known in the art by more than one order of magnitude. The electrical conductivity enhancement depends on the weight fraction (F) of the single-wall carbon nanotubes in the composite. The electrical conductivity of the composite of this invention is at least 5 Siemens per centimeter (S/cm) at (F) of 0.5 (i.e. where single-wall carbon nanotube loading weight represents half of the total composite weight), at least 1 S/cm at a F of 0.1, at least 1×10^{−4 S/cm at (F) of 0.004, at least 6×10−9} S/cm at (F) of 0.001 and at least 3×10⁻¹⁶ S/cm (F) plus the intrinsic conductivity of the polymer matrix material at of 0.0001. The thermal conductivity enhancement is in excess of 1 Watt/m-° K. The polar polymer can be polycarbonate, poly(acrylic acid), poly(acrylic acid), poly(methacrylic acid), polyoxide, polysulfide, polysulfone, polyamides, polyester, polyurethane, polyimide, poly(vinyl acetate), poly(vinyl alcohol), poly(vinyl chloride), poly(vinyl pyridine), poly(vinyl pyrrolidone), copolymers thereof and combinations thereof. The composite can further comprise a nonpolar polymer, such as, a polyolefin polymer, polyethylene, polypropylene, polybutene, polyisobutene, polyisoprene, polystyrene, copolymers thereof and combinations thereof.

The invention relates to a colorless and transparent polyimide nano-composite material membrane and a preparation method thereof. The polyimide nano-composite material membrane is prepared by a method of compounding alicyclic dianhydride and fluorinated diamine serving as monomers with a certain amount of inorganic nano-particles by using nano-composite technology and performing thermal imidization with gradient temperature increase. The amount of added nano-particles is controlled between 0.01 and 5.00 weight percent to obtain the colorless and transparent polyimide nano-composite material membrane with high heat resistance. The membrane has a glass transition temperature of over 250 DEG C, a light transmittance of over 90 percent at 450 nanometers and an ultraviolet wavelength of about 300 nanometers, and can be used as a substrate material for a photoelectric device, a semiconductor material, an optical waveguide material and the like.

Metal-organic framework (MOF)-polymer mixed matrix membranes (MOF-MMMs) have been prepared by dispersing high surface area MOFs (e.g. IRMOF-1) into a polymer matrix (e.g. Matrimid 5218). The MOFs allow the polymer to infiltrate the pores of the MOFs, which improves the interfacial and mechanical properties of the polymer and in turn affects permeability. Pure gas permeation tests show the incorporation of 20 wt-% of IRMOF-1 in Matrimid 5218 polyimide matrix results in 280% improvement in CO₂ permeability without a loss of CO₂/CH₄ selectivity compared to those of the pure Matrimid 5218 membrane. This type of MOF-MMMs has significantly improved gas separation performance with dramatically high CO₂ permeability (>35 barrer) and higher than 29 CO₂/CH₄ selectivity at 50° C. under 100 psig pressure, which are attractive candidates for practical gas separation applications such as CO₂ removal from natural gas.

Integrated circuit device packages and substrates for making the packages are disclosed. One embodiment of a substrate includes a planar sheet of polyimide having a first surface, an opposite second surface, and apertures between the first and second surfaces. A planar metal die pad and planar metal are attached to the second surface of the polyimide sheet. The apertures in the polyimide sheet are juxtaposed to the leads. A package made using the substrate includes an integrated circuit device mounted above the first surface of the polyimide sheet opposite the die pad. Bond wires are connected between the integrated circuit device and the leads through the apertures in the polyimide sheet. An encapsulant material covers the first surface of the polyimide sheet, the integrated circuit device, the bone wires, and the apertures. The die pad and leads are exposed at an exterior surface of the package.

Oral care compositions comprising: (a) a peroxide complex comprising a peroxide component and an N-vinyl heterocyclic polymer (e.g., poly-N-vinyl polylactam, or poly-N-vinyl-polyimide); (b) a whitening agent (e.g., hydrogen peroxide); and (c) an orally acceptable carrier. In one embodiment, the carrier comprises a film forming material. Methods are also provided for making an oral care composition comprising: (a) mixing a whitening agent, silicone adhesive and carrier fluid to form a homogenous mixture; (b) adding a peroxide complex to said homogenous mixture, wherein said complex comprises hydrogen peroxide and an N-vinyl heterocyclic polymer; and (c) mixing under vacuum.

A lithium secondary battery includes an electrode assembly having a positive electrode (1), a negative electrode (2) having a negative electrode current collector and a negative electrode active material layer formed on a surface of the negative electrode current collector and composed of a binder and negative electrode active material particles containing silicon and/or a silicon alloy, and a separator (3) interposed between the electrodes. The electrode assembly is impregnated with a non-aqueous electrolyte. The binder contains a polyimide resin represented by the following chemical formula (1):

where R contains at least a benzene ring, and n is within the range of from 10 to 100,000, and the negative electrode active material particles have an average particle size of 5 μm or greater.

A connector system (20) connects a leadless integrated circuit (IC) device (22) to a printed circuit (PC) board (24) by means of a contact array (26). The contact array (26) connects input-output (I/O) contacts on the IC device (22) to corresponding circuit contacts (28) on PC board (24). The contact array (26) is a generally thin, flexible and rectangular shaped element that is sandwiched between the PC board (24) and the IC device (22). The contact array (26) has a plurality of square cells (30) that are each a portion of the array (26) and are formed from a planar body (32) of a suitable conductive material, such as beryllium copper, sandwiched between suitable insulating films, formed from polyimide. Each cell is divided into a first pair (34) of contact elements (36) extending above the plane of the body (32) and a second pair (38) of contact elements (36) extending below the plane of the body (32).

Mixed matrix membranes are prepared from zeolites and polymers, such as polyimides, in a void free fashion where either no voids or voids of less than several Angstroms are present at the interface of the polymer and the zeolite by bonding (hydrogen, ionic, or covalent) functional groups on the zeolite with functional groups on the polymer. The mixed matrix membranes may be cast or formed by ISAM processes, and may be present on a variety of supports including hollow fibers.

Electroactive polymers are produced via electrospinning. The induction of electroactivity via electrospinning can be utilized with one or more soluble polymers with polarizable moieties. Suitable polymer classes include but are not limited to polyimides, polyamides, vinyl polymers, polyurethanes, polyureas, polythioureas, polyacrylates, polyesters, and biopolymers. Any one or more solvents sufficient to dissolve the one or more polymers of interest and make a spinnable solution can be utilized. The polymer can be electrospun into fiber and fibrous nonwoven mat. The electroactive polymer can be doped with inclusions, such as nanotubes, nanofibers, and piezoceramic powders for dielectric enhancement The availability of electroactive polymer fibers and fibrous nonwoven mat will enable many new applications for electroactive polymers.

A voltage variable material (“VVM”) including an insulative binder that is formulated to intrinsically adhere to conductive and non-conductive surfaces is provided. The binder and thus the VVM is self-curable and applicable in a spreadable form that dries before use. The binder eliminates the need to place the VVM in a separate device or to provide separate printed circuit board pads on which to electrically connect the VVM. The binder and thus the VVM can be directly applied to many different types of substrates, such as a rigid FR-4 laminate, a polyimide, a polymer or a multilayer PCB via a process such as screen or stencil printing. In one embodiment, the VVM includes two types of conductive particles, one with a core and one without a core. The VVM can also have core-shell type semiconductive particles.

The invention is directed to a method of bonding a hermetically sealed electronics package to an electrode or a flexible circuit and the resulting electronics package, that is suitable for implantation in living tissue, such as for a retinal or cortical electrode array to enable restoration of sight to certain non-sighted individuals. The hermetically sealed electronics package is directly bonded to the flex circuit or electrode by one of several methods, including attachment by an electrically conductive adhesive, such as epoxy or polyimide, containing platinum metal flake in biocompatible glue; diffusion bonding of platinum bumps covered by an insulating layer; thermal welding of wire staples; or an integrated interconnect fabrication. The resulting electronic device is biocompatible and is suitable for long-term implantation in living tissue.

The invention relates to a resin bonding agent diamond grinding wheel and a manufacturing method thereof, and the grinding wheel comprises a grinding medium layer and a base body, wherein, the grinding medium layer is arranged on the base body and comprises diamond grinding medium, resin bonding agent, filling reinforcement which is a copper cladded iron powder and auxiliary abrasives which can be one or the combination of carborundum, boron carbide, white alundum, single alundum and fused zirconia alumina. The grinding medium layer comprises 5-15% of diamond grinding medium, 10-25% of auxiliary abrasive, 25-50% of thermosetting polyimide resin, 3-10% of copper cladded iron powder, 15-40% of silicon carbide powder and 0-8% of filling of metallic oxide in terms of volume percent. The diamond grinding wheel is characterized by low production cost, strong adhesive force, good sharpness and self-sharpness, long service life and good abrasion cutting effect.

There are provided a thin wire grid polarizer having a high transmittance, a high quenching ratio and a high degree of polarization, and a method for producing the same at low costs. A fluoridated polyimide thin film 12, a hydrophilic thin film 13 and a hydrophobic thin film 14 are sequentially stacked on a glass substrate 11 to be pressed by a die 1 from the side of the hydrophobic thin film 14 to transfer the fine pattern of groove forming protrusions 3 of the die 1 to the hydrophobic thin film 14 and hydrophilic thin film 13 by the nano-imprinted lithography technique, and then, metal fine wires are caused to grow by plating.

The invention discloses a liquid crystal display, which comprises two substrates and liquid crystals between the substrates. A pixel area and a peripheral area are formed on the substrate. A sealant line is formed on the edge of the peripheral area. The liquid crystal display also comprises at least one orientation layer barrier layer, wherein the orientation layer barrier layer is formed between the pixel area and the sealant line, and comprises a plurality of barriers and a plurality of openings; and the barriers and the openings are arranged alternately. In the liquid crystal display, the openings formed between the orientation layer barrier layers can prevent the diffusion of polyimide film (PI) solution to the sealant line and also prevent the PI solution from being accumulated and further upstream diffused towards the pixel area when flowing to the orientation layer barrier layer, thereby improving the uniformity of an orientation layer formed on the substrate and the display quality of pictures.

Embodiments of the invention include a method comprising disposing a thin metallic layer having a low melting temperature between one end of a conductive post on a substrate and a conducting structure on an opposing substrate. Heated platens in contact with the substrates can apply pressure and heat to the thin metallic layer and cause it to be entirely consumed and subsequently transformed into a bonding layer having a melting temperature higher than the melting temperature of the original thin metallic layer. Prior to, during, or after the conductive post is bonded to the conducting structure, the region around the conductive post and between the substrates may be filled with a dielectric material, such as polyimide.

The invention discloses a flexible current collector for a lithium battery and a preparation method thereof. The flexible current collector comprises a flexible substrate layer, a metal conductive plated layer and a conductive anti-oxidization layer which are combined tightly in sequence, wherein the flexible substrate layer is one of polyvinyl chloride, polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polydimethylsiloxane and polyimide; the thickness of the flexible substrate layer is 1-20 microns; the metal conductive plated layer is one of Cu, Al, Ni, Au and Ag and the thickness of the metal conductive plated layer is 0.1-5 microns; and the conductive anti-oxidization layer is at least one of conductive graphite, graphene, carbon nanotubes and carbon nano-fibers, and the thickness of the conductive anti-oxidization layer is more than 0 and smaller than 1 micron. The flexible current collector disclosed by the invention has high machinability and relatively high thermal stability and anti-oxidization energy; and the quality density of a whole body is small.

The invention discloses a method for manufacturing a high thermal conductivity graphite film, which adopts polyimide films as raw materials and is formed through two processes of carbonization and graphitization. The technological processes of the high thermal conductivity graphite film comprise the steps as follows: a, the polyimide films are selected as the raw materials, and a piece of graphite paper is clamped between each layer of the polyimide films; b, the polyimide films which are provided with the graphite paper at intervals, crossed and stacked are placed into a carbonization furnace to be carbonized in an environment of nitrogen or argon, the carbonized temperature ranges from 1000 DEG C to 1400 DEG C, and the time is controlled from 1 hour to 6 hours; and c, after the carbonization, the graphitization is performed also in the environment of nitrogen or argon, the temperature is controlled in a range from about 2500 DEG C to 3000 DEG C, and the time is controlled within 12 hours. The method for manufacturing the high thermal conductivity graphite film has a simple manufacturing process, the high heat dissipation capacity of the graphite film is guaranteed, the bending-resistant performance is enhanced, and a requirement for a thin and light electronic product of a consumer is met to a certain extent.

The present invention is for novel high performance cross-linkable and cross-linked mixed matrix membranes and the use of such membranes for separations such as for CO₂/CH₄, H₂/CH₄ and propylene/propane separations. More specifically, the invention involves the preparation of cross-linkable and cross-linked mixed matrix membranes (MMMs). The cross-linkable MMMs were prepared by incorporating microporous molecular sieves or soluble high surface area microporous polymers (PIMs) as dispersed microporous fillers into a continuous cross-linkable polymer matrix. The cross-linked MMMs were prepared by UV-cross-linking the cross-linkable MMMs containing cross-linkable polymer matrix such as BP-55 polyimide. Pure gas permeation test results demonstrated that both types of MMMs exhibited higher performance for CO₂/CH₄ and H₂/CH₄ separations than those of the corresponding cross-linkable and cross-linked pure polymer matrices.

The present invention provides overvoltage circuit protection. Specifically, the present invention provides a voltage variable material (“VVM”) that includes an insulative binder that is formulated to intrinsically adhere to conductive and nonconductive surfaces. The binder and thus the VVM is self-curable and may be applied to an application in the form of an ink, which dries in a final form for use. The binder eliminates the need to place the VVM in a separate device or for separate printed circuit board pads on which to electrically connect the VVM. The binder and thus the VVM can be directly applied to many different types of substrates, such as a rigid (FR-4) laminate, a polyimide or a polymer. The VVM can also be directly applied to different types of substrates that are placed inside a device.

The present invention is directed to the preparation and use of aromatic polyimide nanowebs with amide-modified surfaces. Uses include as a filtration medium, and as a separator in batteries, particularly lithium-ion batteries. The invention is also directed to a filtration apparatus comprising the aromatic polyimide nanoweb with amide-modified surface. The invention is further directed to a multi-layer article comprising the aromatic polyimide nanoweb with amide-modified surface, and to an electrochemical cell comprising the multi-layer article.

A separator for non-aqueous electrolyte batteries is provided that has small heat shrinkage and achieves good heat resistance and good cycle performance. A non-aqueous electrolyte battery using the separator is also provided. A separator for non-aqueous electrolyte batteries includes a microporous film in which a polyolefin layer and a heat-proof layer are adhered. The heat-proof layer has a thickness of from 1 μm to 4 μm, and is formed of polyamide, polyimide, or polyamideimide having a melting point of 180° C. or higher. The air permeability of the separator is 200 sec/100 mL or less.

Embodiments in accordance with the present invention relate to methods and apparatuses for bonding together substrates in a manner that suppresses the formation of voids between them. In a specific embodiment, a backside of each substrate is adhered to a front area of flexible, porous chuck having a rear area in pneumatic communication with a vacuum. Application of the vacuum causes the chuck and the associated substrate to slightly bend. Owing to this bending, physical contact between local portions on the front side of the flexed substrates may be initiated, while maintaining other portions on front side of the substrates substantially free from contact with each other. A bond wave is formed and maintained at a determined velocity to form a continuous interface joining the front sides of the substrates, without formation of voids therebetween. In one embodiment, the chucks may comprise porous polyethylene sealed with polyimide except for a portion of the front configured to be in contact with the substrate, and a portion of the backside configured to be in communication with a vacuum source.

A composition for the manufacture of a porous, compressible article, the composition comprising a combination of: a plurality of reinforcing fibers; a plurality of polyimide fibers; and a plurality of polymeric binder fibers; wherein the polymeric binder fibers have a melting point lower than the polyimide fibers; methods for forming the porous, compressible article; and articles containing the porous, compressible article. An article comprising a thermoformed dual matrix composite is also disclosed, wherein the composite exhibits a time to peak release, as measured by FAR 25.853 (OSU test), a 2 minute total heat release, as measured by FAR 25.853 (OSU test), and an NBS optical smoke density of less than 200 at 4 minutes, determined in accordance with ASTM E-662 (FAR/JAR 25.853).

A single chip wireless sensor (1) comprises a microcontroller (2) connected to a transmit/receive interface (3), which is coupled to a wireless antenna (4) by an L-C matching circuit. The sensor (1) senses gas or humidity and temperature. The device (1) is an integrated chip manufactured in a single process in which both the electronics and sensor components are manufactured using standard CMOS processing techniques, applied to achieve both electronic and sensing components in an integrated process. A Low-K material (57) with an organic polymer component is spun onto the wafer to form a top layer incorporating also sensing electrodes (60). This material is cured at 300° C., which is much lower than CVD temperatures. The polyimide when cured becomes thermoset, and the lower mass-to-volume ratio resulting in K, its dielectric constant, reducing to 2.9. The thermoset dielectric, while not regarded as porous in the conventional sense, has sufficient free space volume to admit enough gas or humidity for sensing.

An apparatus for and method of minimizing the thermo-mechanical fatigue of flip-chip packages. The interposer of the present invention, preferably comprising an organic polymer such as polyimide, contains apertures having conductive plugs inserted therein for joining a chip to a substrate in an electronic module utilizing flip-chip packaging. The interposer is selected to provide optimum spacing between the chip and substrate having a coefficient of thermal expansion adapted to the thermal cycling temperature extremes of the module components. The interposer may comprise an inner core with two adhesive outer layers which may comprise different materials to promote adhesion at their respective interfaces within a module. Conductive plugs are disposed within the apertures of the interposer comprising of a first and second solder or comprising a conductive plug having top and bottom surfaces coated with a conductive adhesive. Preferably, the first solder is disposed within an interior of the apertures and the second solder is disposed within an exterior of the apertures such that the first solder is between a first portion and a second portion of the second solder. Upon reflow, the second solder is reflowed while the first solder remains solid.

Disclosed is a polyimide coated shape memory material suitable for thermomechanical treatment to shape-set the material into the desired configuration and activate shape memory properties. The polyimide coating is subjected to a curing regime that imparts higher heat resistance in the polyimide coating to withstand the elevated temperatures required during the shape-setting treatment.

A photosensitive resin composition of the present invention contains a (A) soluble polyimide and a (b) (meth)acrylic compound, the (A) soluble polyimide being soluble in an organic solvent and being synthesized by using an acid dianhydride component and at least one of a diamine component containing a siloxane structure or an aromatic ring structure, and a diamine component having, in its structure, a hydroxyl group a carboxyl group or a carbonyl group, and the (B) (meth)acrylic compound having at least one carbon-carbon double bond, and preferably contains at least one of a (C) photo reaction initiator and a (D) fire retardant. With this arrangement, the photosensitive resin composition of the present invention is capable of having excellent properties. Especially, the photosensitive resin composition of the present invention is so excellently useful that it can be used for electronic parts and the like.