Semiconductor device
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Jun 18, 1991
Grant Date -
N/A
app pub date -
Apr 11, 1989
filing date -
Apr 13, 1988
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
A semiconductor device of a type having a pin grid array, comprises a printed circuit board and a planar metal stem with a plurality of through holes. The stem is made of metal having a coefficient of thermal expansion .alpha.s. The printed circuit board has a predetermined wiring pattern on its upper surface and is made of a material having a maximum coefficient .alpha.p in the widthwise direction. The printed circuit board is superposed over the upper surface of the metal stem. A plurality of lead pins have upper portions inserted into the through holes of the stem and board and are in alignment with each other when the board and the stem are superposed one upon another. Connecting members connect the upper portions of the lead pins with their corresponding wiring patterns. In the semiconductor device, the absolute value .DELTA..alpha. of the difference between the maximum coefficient .alpha.p of the board and the coefficient .alpha.s of the stem (.DELTA..alpha.=.alpha.p -.alpha.s) is less than or equal to '1.52.times.10.sup.-4 /L' (.DELTA..alpha..ltoreq.1.52 .times.10.sup.-4 /L).
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