Abstract:
An electrical substrate material is presented comprising a resin matrix which includes a thermosetting polybutadiene or polysoprene resin, and ethylene propylene rubber, and optionally a thermoplastic unsaturated butadiene- or isoprene-containing polymer; a particulate filler, a flame retardant addititive, a curing agent, and a woven or unwoven fabric. The presence of the ethylene propylene rubber enhances the heat age properties of the substrate material, particularly the dielectric strengh and the mechanical properties, while other electrical, chemical, and mechanical properties of the material are not adversely effected.
Abstract:
The invention concerns a planar electric circuit support comprising a substrate (1) based on a solid material consisting of a polymer matrix (4) wherein are bound glass fibre pieces (3), the proportion by weight of the glass fibre pieces in the polymer matrix being more than 50 %, the glass fibre pieces being advantageously longer than 200 micrometers.
Abstract:
To avoid gaps in throughplating in case of important variations in temperature, non-conductive, non-deformable particles, for example glass-fibre particles (3), are introduced into the expoxy resin contact mass by a polymerization process during production of said printed circuit boards.
Abstract:
Thermotropic liquid crystalline polymers are readily ground to smaller particle sizes by using a two or more stage grinding process. The particles produced usually are relatively short, but still, fibers. The ground LCP is useful for rotational molding, powder coating, and forming nonwoven structures.
Abstract:
A heat-resistant fibrous paper which is formed mainly from short fibers made of a heat-resistant organic polymer, short fibers made of an unstretched or lowly stretched para-aromatic polyamide, and an organic resin binder and/or fibrids made of a heat-resistant organic polymer, wherein the amount of the short fibers is 45 to 97 wt.% based on the whole paper, the amount of the organic resin binder and/or the fibrids is 3 to 55 wt.%, and the organic resin binder has been cured and/or the short fibers of an unstretched or lowly stretched para-aromatic polyamide and the fibrids were partly softened and/or deformed and melted to make them serve as a binder. This heat-resistant fibrous paper is excellent in heat resistance, thermal dimensional stability, interlaminar peel strength, electrical insulating properties in a high-humidity atmosphere, etc. and can be satisfactorily impregnated with a resin despite its high bulk density. It is especially suitable for use as a substrate for electrical insulating materials or a substrate for layered products for electrical circuits.