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:
May. 06, 1980
Filed:
Jun. 23, 1978
Leroy N Chellis, Endwell, NY (US);
Theron L Ellis, Vestal, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A multi-layered printed circuit board is disclosed having a plurality of circuitized laminations therein. The laminates are fabricated or secured by curing layers of glass cloth which have been impregnated with heat curable resins at temperatures in excess of their glass transition temperature, the point at which such material begins to distort. Those laminations which will see at least one further curing cycle, after having themselves been cured, are formed from glass cloth impregnated heat curable resin combinations having a glass transition temperature which is significantly higher than that of the heat curable materials employed to form the subsequently and singly cured laminations. In this manner, lamination shift or distortion is appreciably reduced since those laminations which undergo a plurality of 'curing' cycles, only experience one excursion beyond their transition temperature. Thus, registration mismatch between any of the circuitized laminates will not exceed acceptable levels.