Japan Gore-tex Inc.

Minoru Hatakeyama

Ichiro Komada

Kosuke Moriya

Sunao Fukutake

Akira Urakami

Yoshito Hazaki

A resin-sealed semiconductor device, including a chip mounting die pad, porous fluorocarbon material located just beneath the die pad, beneath a die-pad supporting layer, gold lead wires, or in a sealing resin surrounding the other components, wherein any water vapor generated by the heat of soldering will be held within the porous fluorocarbon rather than crack the sealant under internal pressure.

Resin-sealed semiconductor device containing porous fluorocarbon resin

A flexible base material for use in printed circuit boards is provided wherein a sheet of porous, expanded polytetrafluoroethylene is impregnated with a bismaleimide-triazine resin, and the resin is cured therein. The sheet may be laminated to a glass cloth and composites may be produced having a multiplicity of layers of such sheets and glass cloths.

Flexible printed circuit board base material

A printed circuit board base prepreg material is provided of a porous, expanded polytetrafluoroethylene (PTFE) membrane or fabric impregnated with a polyimide resin varnish. Upon curing, a printed circuit board base material of porous, expanded PTFE impregnated with polyimide resin is provided. The base material of the invention may be laminated to a glass fabric to improve strength and dimensional stability.

Printed circuit board base material

A base material for use in making printed circuit boards is provided wherein minute fragments of expanded, porous polytetrafluoroethylene are uniformly mixed into another resin, and the mixture is compressed to form a composite board. In use, the board has an electrically conductive circuit affixed to at least one surface. The other resin may be epoxy, polyester or other similar resin. Laminates of such base board material affixed to a glass cloth or paper sheet may be prepared. The preferred fragment size range is 0.1 to 5 mm average diameter, and the preferred volume ratio of fragments to resin is 0.5 to 2.0.

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Sakuragaokanishi, Japan

Minoru Hatakeyama