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Browse Prior Art Database

Circuit Board Rework

IP.com Disclosure Number: IPCOM000061390D
Original Publication Date: 1986-Jun-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Capwell, RJ: AUTHOR [+3]

Abstract

In the production of printed circuit boards by additive plating, the boards are sometimes overplated.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

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Circuit Board Rework

In the production of printed circuit boards by additive plating, the boards are sometimes overplated.

One way of removing overplating is to dip the boards in a sodium persulfate bath. It has been found that while this does remove the excess copper, there is excessive etching at the grain boundaries, thereby resulting in degradation of the circuit lines.

This problem can be corrected by using a conveyor etch. In this type of etch process, the boards are placed on a conveyor which passes through a spray of sodium persulfate which is heated and which has a mercuric chloride catalyst. The amount of copper removed can be controlled by controlling the conveyor speed.

Disclosed anonymously.

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