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. 01, 1994
Filed:
Aug. 26, 1993
William T Chen, Endicott, NY (US);
Thomas P Gall, Endwell, NY (US);
James R Wilcox, Vestal, NY (US);
Tien Y Wu, Endwell, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method of making a multilayered circuit board wherein at least two layered subassemblies, each comprising a dielectric layer and at least one conductive layer therein, are bonded together. Each subassembly includes a through-hole extending therethrough which is aligned with a respective through-hole of the other prior to bonding. The subassemblies are compressed at a predetermined pressure (e.g., 300 psi) and then heated to a first temperature (e.g., 300.degree. C.) for an established time period, resulting in formation of a bond between the two through-holes. The resulting alloy formed from this bond possesses a melting point significantly greater than that of the subassembly dielectric (e.g., PTFE). Following this time period, the compressed subassemblies are heated to an even greater temperature (e.g., 380.degree. C.), again for an established time period, to assure dielectric flow. The subassembly is then cooled and the pressure removed. The method possesses two significant features: (1) effective engagement between respective pairs of through-holes in the compressed subassemblies; and (2) prevention of dielectric incursion within the bond formed between the respective pairs of through-holes, which incursion could adversely affect the electrical connection therebetween.