Multilayered circuit board

Abstract

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° 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° 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.

Inventors

• 👤 William T. Chen
• 👤 Thomas P. Gall
• 👤 James R. Wilcox
• 👤 Tien Y. Wu

Bibliographic Details