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Chemical Smut Removal For MLC Plating Rework

IP.com Disclosure Number: IPCOM000048587D
Original Publication Date: 1982-Feb-01
Included in the Prior Art Database: 2005-Feb-08
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Dzwilefsky, JW: AUTHOR [+5]

Abstract

An etchant solution is provided for removing I/O blisters occurring on TCM (thermal conduction module) substrates requiring subsequent plating rework.

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Chemical Smut Removal For MLC Plating Rework

An etchant solution is provided for removing I/O blisters occurring on TCM (thermal conduction module) substrates requiring subsequent plating rework.

Typically, a "smut" of moly oxide and organic contaminants remains on TCM surface metallurgy after stripping the prior plating in KI/I(2) etchant. The smut later prevents diffusion of nickel plating into the molybdenum and results in a blister on the larger I/O pads. On the top surface, the features are too small to blister, but the poor adhesion leads to bondability failures.

It has been shown that a 15-second dip, for example, in potassium ferricyanide solution (K(3)Fe(CN)(6) - 215 g/1. KOH - 71.6 g/1) removes the smut, prevents the formation of I/O blisters, and decreases bondability failures.

Prior to this approach. removal of moly oxides and hydroxides was accomplished by mechanical means. This caused oxides to become imbedded in the ceramic, and later resulted in electroless nickel plating on the ceramic.

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