Abstract:
A multilayer printed circuit board comprising a laminate of at least one glass fiber nonwoven cloth layer impregnated with thermosetting resin and glass fiber woven cloth layers impregnated with thermosetting resin, the laminate having a pair of V-cut grooves formed therein so that only the glass fiber nonwoven cloth layer remains uncut whereby the multilayer printed circuit board can be divided at the uncut glass fiber nonwoven cloth layer along the V-cut grooves into a plurality of printed circuit board portions which can be mounted having a practical size.
Abstract:
A flexible sheet which comprises a non-woven fabric made predominantly from a poly(aromatic amide) component which is impregnated with a heat- and/or light-curable resin, wherein the non-woven fabric satisfies the following conditions:5 g/m.sup.2
Abstract translation:一种柔性片材,其包含主要由浸渍有热和/或光可固化树脂的聚(芳香族酰胺)成分制成的无纺织物,其中所述无纺布满足以下条件:5g / m 2 单位面积重量<35g / m 2,0.15g / cm 3密度<0.8g / cm 3,具有良好的平衡性,例如优异的热尺寸稳定性,耐热性(耐焊接性),耐水性 ,耐溶剂性,电绝缘性能和机械性能,并且可用于制备柔性印刷电路板,以及其用于柔性覆金属层压板和柔性印刷电路板的用途。
Abstract:
Disclosed are improved laminates useful in the manufacture of multi-layer printed wiring boards (MLPWB) and laminates. Such improved composites contain at least one layer which is formed from a liquid crystal polymer selected from the group consisting of poly(para-phenylene benzobisthiazole), poly(paraphenylene benzobisoxazole), poly(2,5-benzothiazole), poly(2,5-benzoxazole), and mixtures thereof. The presently preferred liquid crystal polymer comprises poly(para-phenylene benzobisthiazole). The negative coefficient of thermal expansion and high modulus of elasticity of the liquid crystal polymers enable a laminate and MLPWB to be manufactured therefrom having a tailored coefficient of thermal expansion, broadly ranging from about 0 to 15 ppm/.degree. C. MLPWBs constructed of polymeric core layers also are possible utilizing the preferred liquid crystal polymers of the present invention.
Abstract:
High density para-aramid papers comprising 5 to 25 percent, by weight, binder and an amount of para-aramid fibers selected from the group consisting of para-aramid pulp, para-aramid floc and mixtures thereof, compacted to provide a volume percent para-aramid fiber of at least 53 minus 0.13 times the volume percent floc in the paper are useful in the preparation of circuit board substrates having a low coefficient of thermal expansion.
Abstract:
A laminated board lined with thermally and electrically conductive material, which comprises:(a) a prepreg sheet formed of an alumina paper made from a mixture of alumina fibril, as the principal component, having a fiber diameter of 100 microns or smaller and a fiber length which is ten times or more as long as the fiber diameter, and microfibrillar organic fiber as a binding agent, and a thermosetting resin; and(b) an electrically conductive material in foil such as copper or aluminum bonded to said prepreg sheet.
Abstract:
There are disclosed synthetic mica papers, substrates produced by laminating such papers, and use of the substrates in printed circuit assemblies. The mica paper is composed primarily of overlapping, ion-exchanged platelets of a synthetic, lithium and/or sodium, water-swelling mica, and is impregnated with an organic resin.
Abstract:
A prepreg useful as the core in flame resistant cooper clad, composite, printed circuit boards is made by impregnating a porous substrate with an impregnant containing: either a brominated epoxy or epoxy resin and reactive flame retarding additive containing bromine and phenolic hydroxyl groups (e.g., tetrabromobisphenol A), phenolic novolac oligomer as curing agent, unsaturated epoxidized oil, and optionally, a suitable catalyst; and then heating the impregnated substrate to the "B"-stage.
Abstract:
A metallized, laminated substrate well adapted for the production of printed circuits is comprised of:(A) an electrically insulating support element which comprises (a) a central core member comprising a major proportion by weight of a cellulosic or mica filler and a minor proportion by weight of a thermosetting resin, and (b) and (b') a pair of skin laminae coextensively secured to each face surface, respectively, of said central core (a) each of said skin laminae comprising a fibrous glass, asbestos or heat-stable synthetic polymer reinforcing filler, and a thermosetting resin impregnant, which thermosetting resin may either be the same as or different from the thermosetting resin comprising said central core member (a); and(B) an electrically conducting metal foil (c) coextensively adhered to the exposed face surface of one or the other of said skin laminae (b) or (b').
Abstract:
A resin impregnated, B-staged sheet material free of crystal formations, useful for metal clad and unclad laminate production, is made by impregnating a sheet containing a resin comprising epoxy resin and an amount of curing agent effective to cure the epoxy resin to the C-stage, where the curing agent consists essentially of the reaction product of dicyandiamide and an aminophylic reagent selected from the group consisting of aldehydes, alkyl monoglycidyl ethers having the formula: ##STR1## where R=an alkyl group having from 1 to 4 carbon atoms, styrene oxide, ethylene oxide, propylene oxide, acetic anhydride, benzoyl chloride, acetyl chloride, and mixtures thereof, and then heating the impregnated sheet until the resin is in the B-stage.
Abstract:
In preparing an epoxy resin laminate sheet by impregnating a nonwoven fabric of glass fiber with an epoxy resin to form a prepreg, laminating a predetermined number of so formed prepregs and pressing, while heating, the laminate, when the nonwoven fabric of glass fiber to be used as a substrate is treated with a liquid mixture containing a water-soluble phenol resin and a silane coupler prior to the impregnation step, a laminate sheet suitable for formation of a printed circuit board can be obtained at a low manufacturing cost. The so formed laminate sheet not only has excellent heat resistance, drilling workability and punching workability at room temperature but also is characterized by such an excellent property that when it is subjected to the boiling water treatment, the degree of reduction of electric properties such as the insulation resistance is very small and whitening of the substrate is not caused to occur.