The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 23, 1993
Filed:
May. 13, 1991
Thomas S Kohm, Huntington, NY (US);
AMP-AKZO Corporation, Newark, DE (US);
Abstract
A base material for printed wiring boards is formed by laminating together layers of prepregs of woven cloth impregnated with a thermosetting polymeric resin varnish. The varnish has an inorganic filler which is present in an amount sufficient to provide the base material with an average coefficient of thermal expansion along its Z-axis between 30.degree. C. and 270.degree. C. which is equal to or less than the coefficient of thermal expansion of copper from 30.degree. C. to 270.degree. C. plus the maximum elongation at 270.degree. C. of copper suitable for forming a conductive pattern on hole walls of printed wiring boards. Printed wiring boards manufactured on the base material by additive or subtractive processes are resistant to failure from thermal stress or thermal cycling.