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US 5,706,175 AGranted
Resin-sealed semiconductor device
AssigneeKabushiki Kaisha Toshiba
InventorShinji Takei
Life of this patent
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Abstract
A resin-sealed semiconductor device includes a plurality of electronic components mounted on a printed wiring board, a circuit mounting surface of the board being resin-sealed, with connection terminals of the electronic components electrically connected to a printed wiring on the board. A surface portion of the board is coated with insulator material which contains tiny hollow spheres and constitutes a thermal expansion resin.
Claims2
A resin sealed semiconductor device comprising:
- a printed wiring board having a plurality of wirings on an upper surface portion thereof;
- an electronic component mounted on the board and connected to at least one of the plurality of wirings;
- an insulator material covering the upper surface portion of the board and containing tiny hollow spheres, wherein the insulator material is a resist material formed mainly of an epoxy resin and the insulator coats a printed wire region of the upper surface portion of the board, and wherein the resist material is a thermal expansion resin formed of copolymer of vinylidene chloride or acrylonitrile used as a core and isobutane capsuled as the spheres in the copolymer and used as a foaming agent, the resist material expanding when heated at a temperature of 80 to 150.degree. C. to have a sphere diameter increased from 5 to 30 .mu.m to 10 to 100 .mu.m, and the tiny hollow spheres are mixed in the resist material in an amount of 3 to 10%;
- and
- a resin sealing a part-mounting surface of the wiring board.
2 more elements
Dependencies are inferred from the claim text.