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:
Jan. 14, 1986
Filed:
Nov. 28, 1984
William P Dugan, Pomona, CA (US);
General Dynamics Pomona Division, Pomona, CA (US);
Abstract
Reusable mandrels for fabricating bumped circuit base sheets may be formed by alternative methods. One method involves the selective etching of a copper sheet to develop pits or cavities at predetermined locations. A thin plating layer is deposited on the base sheet, covering the surface including the depressions to form the mandrel. After passivation of the plated surface, copper is plated thereon to form the sheet with the bumps in place. This sheet is then peeled off the mandrel so that the mandrel may be reused for making subsequent bumped sheets. An alternative method of forming the reusable mandrel involves the selected build-up of a base metal sheet by plating with a compatible material about islands of photoresist. Thereafter, the photoresist is removed, leaving cavities where the islands had been. This surface is then plated with a thin layer of nickel to form the permanent mandrel.