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:
Mar. 24, 1992
Filed:
Feb. 06, 1991
Peter J Duke, Endwell, NY (US);
Krystyna W Semkow, Johnson City, NY (US);
International Business Machines Corp., Armonk, NY (US);
Abstract
Disclosed is a method of fabricating a microelectronic package having least one layer formed of a copper-Invar-copper core encapsulated between a pair of dielectric films. The method includes exposing a copper-Invar-copper surface of the copper-Invar-copper core, for example, exposing an edge of the copper-Invar-copper core or drilling a whole through the layer to expose internal copper-Invar-copper. The copper-Invar-copper is then shaped, that is, back etched. This is an electrolytic process where the package is immersed in a substantially pH neutral electrolyte including a counter- electrode. A preferred electrolyte is an aqueous alkali metal nitrate solution. The electrolyte wets the exposed surface of said copper-Invar-copper core. The exposed surface of the copper-Invar-copper core is rendered anodic with respect to the counter-electrode and an electrical potential is applied therebetween. This results in electrochemically etching and shaping the copper-Invar-copper surface.