Browse Prior Art Database

Corrosion-Free Connector Pad

IP.com Disclosure Number: IPCOM000114977D
Original Publication Date: 1995-Feb-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Galasco, R: AUTHOR [+2]

Abstract

Disclosed is a pad metallurgy for first level computer packages entitled corrosion-free connector pad and a fabrication method of this pad. Potential applications of this pad are advanced connector and other systems where pad corrosion is not acceptable.

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Corrosion-Free Connector Pad

      Disclosed is a pad metallurgy for first level computer packages
entitled corrosion-free connector pad and a fabrication method of
this pad.  Potential applications of this pad are advanced connector
and other systems where pad corrosion is not acceptable.

      The metallurgy of the pad is illustrated in the Figure.
Sputtered chromium provides adhesion to ceramic or polyimide
substrate.  Sputtered nickel with textured electroplated nickel
provides commoning layer for electroplate with good resist adhesion.
After resist processing to define pad dimensions, cathodic activation
of nickel surface is performed in sulfuric acid.  Palladium and soft
gold electroplate provide the top surface for mating to advanced
connectors such as dendrites or other pads.  After resist strip,
final pad formation is performed by etching the nickel and chromium
layers with ferric chloride and potassium permanganate respectively.
The lack of copper in the metallurgy eliminates sidewall corrosion of
the pad under typical corrosive gas environment testing.