Abstract:
Process provides wetlaid printed wiring board core stock precursor material that incorporates resin within cellulose matrix and that can be partially cured by conventional means to form PWB B-stage materials (20). Process also provides for reducing dielectric constant and dissipation factor of a PWB core stock and of PWB composite material made therefrom, by incorporating material having dielectric constant lower than that of cellulose fibers directly into cellulose matrix forming the core stock (21). Among materials that can be incorporated into cellulose matrix are fibrous materials, including glass fibers (23) and/or synthetic fibers, and/or particulate constituents such as glass microspheres, glass beads, glass shot, aramid fibers, aramid powders, ceramic microspheres, and clay. Other additives, such as flame retardants, may also be incorporated into novel paperboard materials of the invention.
Abstract:
Light emitting diode (LED) based daylight running light (DRL) comprising a carrier, comprising a polymer composition comprising polyethylene terephthalate and glass fibers, the surface of the carrier comprises conductor tracks for mounting one or more LED's.
Abstract:
Verfahren zum elektrischen Verbinden leitfähiger Fäden (Leitfäden) (40) an beliebig vielen Anschlussstellen eines textilen Halbzeugs (5) mit einem vorzugsweise als Leiterplatte ausgebildeten Anschlusselement, wobei folgende Schritte vorgesehen sind: Einlegen der Leiterplatte in eine entsprechend geformte Ausnehmung einer Tragplatte eines Werkzeugs mit nach oben weisenden Anschlussstellen (122) der Leiterplatte (12); Anordnen des Halbzeugs (5) auf der Leiterplatte (12) derart, dass im Bereich der Anschlussstellen der Leiterplatte (12) eine anzuschließende Anschlussstelle des Halbzeugs (5) zu liegen kommt. Festlegen, vorzugsweise durch Festklemmen des Halbzeugs, benachbart zu und auf einer Seite der Anschlussstellen der Leiterplatte. Vorzugsweise Dehnen des Halbzeugs (5) in Längsrichtung bzw. in die Richtung des Verlaufs der Leitfäden. Festklemmen des Halbzeugs in einem Bereich entgegengesetzt zum ersten Festklemmbereich und benachbart zur gewünschten Anschlussstelle. Verlöten der freigelegten Leitfäden (40) mit den Anschlussstellen der Leiterplatte (12).
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:
Single and multilayer circuit boards (10) are provided which boards (10) have rigid portions (16) and at least one flexible portion (18). The method involves the use of printed circuit techniques to fabricate the board (10) with flexibility being obtained by windowing interconnect layers (22) for the boards (10) and for at least one embodiment, some but not all of the substrates (12) in the flexible area (18). Where only interconnect layers (22) are provided, at least one, but not all, of such layers (22) are windowed in the flexible area (18). A flexible encapsulant (30) is preferably provided over any portion of a substrate (12) having circuitry thereon at least in the flexible portion (18) thereof. A composite material having aramid fibres encapsulated in a resin is utilized for substrates (12) and interconnecting layers (22) for embodiments where large numbers of flexures may be required and/or where high temperature stability is required. Enhanced performance with changes in temperature is also achieved by having all layers formed of substantially the same material and having all circuit bearing layers of substantially the same thickness. Sequential layering may also be provided to enhance flexibility.
Abstract:
A moist fabric of multifilament bundles is coated with a particulate solid material, which is fused and solidified to produce a fiber-reinforced composite web. Deep penetration of the fused resin is effected without need for pressure assistance.
Abstract:
Dimensionally stable resin impregnated laminates for printed wiring board applications are reinforced with from 43 to 57 weight percent of nonwoven aramid sheet having a coefficient of thermal expansion of less than 10 ppm per DEG C, a basis weight of from 0.8 to 4.0 oz/yd , a density of from 0.5 to 1.0 g/cc and a Gurley Hill Porosity of less than 10 sec.
Abstract:
An entry material for use in drilling circuit boards to avoid marring of such boards comprises a wood pulp-glass composite substrate (14) having aluminum foil (15, 16) bonded to the opposite surfaces thereof. This entry material is relatively economical and has a stiffness sufficient to avoid upward bending or "oil canning" when pressure feet spaced from the drill are employed to hold the workpiece during drilling and further has enough strength to withstand high torsional drill forces with drills operating for high rates of material removal. The double layers of foil separated by the low heat conductive substrate material affords a pair of heat sinks which more effectively can carry away heat from the drill.