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US 4,963,425 AGranted
Printed wiring board substrate for surface mounted components
AssigneeUnisys Corporation
InventorsAlan M. Buchanan, Jay S. Abramowitz, Roberta A. Y. Flygare
Life of this patent
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Abstract
A laminated printed wiring board having surfaces thereof fabricated from conventional fiber reinforced laminates which are secured together by means of an adhesive fabricated of a reinforced thermosetting resin having a coefficient of thermal expansion (CTE) which is substantially smaller than the CTE of the surface laminate whereby the apparent CTE of the overall printed wiring board assembly is substantially controlled.
Claims20
A composite circuit board structure comprising,
- first and second printed wiring boards fabricated of a generally electrically non-conductive material adapted to receive and support thereon at least one component having a coefficient of thermal expansion which is less than the coefficient of thermal expansion of said printed wiring boards, and
- a thermoset adhesive layer disposed between and adhered to each of said first and second printed wiring boards,
- said adhesive layer having a coefficient of thermal expansion which is less than the coefficient of thermal expansion of said component and capable of restraining the expansion rate of said first and second printed wiring boards whereby the apparent coefficient of thermal expansion of the composite circuit board structure approaches that of each said component.
Dependencies are inferred from the claim text.