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:
Jul. 07, 1981
Filed:
Jan. 17, 1980
Charles J Bartlett, Madison, NJ (US);
Ronald J Rhodes, South Plainfield, NJ (US);
Ray D Rust, Berkeley Heights, NJ (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
Multilayer printed wiring boards are conventionally laminated using epoxy adhesives. When the boards are drilled, a residual smear often remains within the drilled holes. This smear prevents proper through plating of the holes and the layers are left without some of the intended interconnections. In the past, the residual smear was removed by wet etching. A technique is described using plasma etching with the conductive surface layers of the drilled boards as the electrodes to generate the plasma. The plasma forms directly within the holes and effectively removes the smear. A dielectric material in contact or close proximity to the perimeter of each board provides uniformity of treatment over the panels.