Abstract:
A solid sheet which contains an nonwoven fabric made from short high tensile modulus fibers and a thermoplastic polymer having a low moisture absorption matrix resin that is useful as a substrate for circuit boards.
Abstract:
The present invention relates to a nonwoven substrate, and specifically to a nonwoven substrate imparted with a three-dimensional image, wherein the three-dimensional nonwoven substrate is particularly suited as a support substrate for a PCB (Printed Circuit Board) and similar application. By the utilization of a hydroentangled, three-dimensionally imaged support substrate impregnated with a durable resinous matrix, PCB's, and similar applications, can be imparted with unique and useful performance properties, to improve structural performance.
Abstract:
This invention relates to a heat conductive resin substrate which polybenzasol fibers are oriented in a thick direction and/or a direction of a surface of a resin substrate, further to the heat conductive resin substrate and a semiconductor package excellent in heat radiation ability which the semiconductor chips are mounted on the heat conductive resin substrate which the polybenzasol fibers are oriented in the thick direction (the Z direction) and/or the direction of the surface of the resin substrate, the heat conductive resin substance and the semiconductor package being provided with electrical insulation and high thermal conductivity, and being capable of controlling the thermal expansion coefficient.
Abstract:
A wholly aromatic polyamide (aramid) fiber synthetic paper sheet includes 70-96 wt % of an aramid staple fiber component which includes 30 wt % or more of a para-type aramid staple fibers each having two or more annular projections spaced from each other and having an average ratio R/&ggr; of the largest diameter R of the annular projections to the smallest diameter &ggr; of the annular projection-free portions of the staple fiber, of 1.1 or more, and 4-30 wt % of a binder component, namely a resinous binder and/or heat resistant fibrids.
Abstract:
A printed circuit board is made from at least one non-woven sheet or web layer comprising at least 50% by weight acrylic fibers, with any balance substantially electrically non-conductive fibers, filler, and binder. The sheet or web is preferably made by the foam process, and may contain 60-80% straight polyacrylonitrile fibers and 40-20% fibrillated (pulp) ones. The web or sheet is preferably compressed by thermal calendering so that it has a density of about 0.1-1 grams per cubic centimeter; and the web or sheet may have a basis weight of between about 20-120 grams per square meter. The web or sheet may also have a 1-40% of substantially electrically non-conductive organic or inorganic binder, or may be substantially binder free. A printed circuit board made using the layers of these non-woven webs or sheets is otherwise conventional, including a pre-preg material, electrically conductive circuit elements, and electronics, and has improved properties compared to woven glass and non-woven aramid products, including improved fiber consolidation, easy board construction, and improved MD/CD ratio and stability.
Abstract:
In manufacturing a double-layered or a multi-layered printed wiring board, a layer of metamorphic substance, which is created by transmuting a substrate material, is formed on an inner wall of a hole during a perforation process of the substrate utilizing radiation energy. The layer of metamorphic substance prevents conductive materials constituting electrical connection means formed on the inner wall of the hole from dispersing over a surface of the substrate or permeating into the substrate.
Abstract:
In manufacturing a double-layered or a multi-layered printed wiring board, a layer of metamorphic substance, which is created by transmuting a substrate material, is formed on an inner wall of a hole during a perforation process of the substrate utilizing radiation energy. The layer of metamorphic substance prevents conductive materials constituting electrical connection means formed on the inner wall of the hole from dispersing over a surface of the substrate or permeating into the substrate.
Abstract:
Disclosed is a printed circuit board, and a method of preparing a printed circuit board, which possesses a coefficient of thermal expansion substantially similar to that of silicon for use in direct semiconductor chip attach structures and similar solder mounted devices. The printed circuit board is fabricated from prepreg having a thermosetting resin and a reinforcement layer consisting of non-woven aramid mat or a liquid crystalline polymer paper. The composite dielectric layer optionally includes plated through holes which are either filled or non-filled, and one or more thin film redistribution layers to provide high density electronic packages. The design places the solder pads at the PTHs where needed. The redistribution layer can be formed using photoimagable dielectrics or laminated controlled-CTE composites and laser via imaging.
Abstract:
A heat resistant fiber sheet composed of staple fibers consisting of a heat resistant organic high molecular polymer and fibrids consisting of a heat resistant organic high molecular polymer as main components, having excellent heat resistance, dimensional stability to heat, interlaminar peeling strength, electric insulation resistance under a high humidity, etc., and also good resin impregnating property in spite of having a high bulk density, and especially suitable for a base substrates for an electric insulating material and a laminate for an electric circuit, is obtained by setting the amount of the staple fibers occupying in the total amount of the sheet as 40 to 97% by weight and the amount of the fibrids as 3 to 60% by weight and partially softening and/or melting the fibrids so as to act as a binder.
Abstract:
A printed circuit board is made from at least one non-woven sheet or web layer comprising at least 50% by weight acrylic fibers, with any balance substantially electrically non-conductive fibers, filler, and binder. The sheet or web is preferably made by the foam process, and may contain 60-80% straight polyacrylonitrile fibers and 40-20% fibrillated (pulp) ones. The web or sheet is preferably compressed by thermal calendering so that it has a density of about 0.1-1 grams per cubic centimeter; and the web or sheet may have a basis weight of between about 20-120 grams per square meter. The web or sheet may also have a 1-40% of substantially electrically non-conductive organic or inorganic binder, or may be substantially binder free. A printed circuit board made using the layers of these non-woven webs or sheets is otherwise conventional, including a pre-preg material, electrically conductive circuit elements, and electronics, and has improved properties compared to woven glass and non-woven aramid products, including improved fiber consolidation, easy board construction, and improved MD/CD ratio and stability.