Browse Prior Art Database

Technique for Making Cards And Boards Repairable

IP.com Disclosure Number: IPCOM000037729D
Original Publication Date: 1989-Jun-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Hagstrom, RA: AUTHOR

Abstract

The repair of cards and boards results in a significant loss of copper particularly in the plated-through holes. However, it has been discovered that by the simple application of a coating of electroless nickel (boron, not phosphorus) after all etching has been completed and finally, followed by a thin layer of electroless gold or solder dip will render such card or board plated in this manner capable of sustaining repeated rework without degradation in the plated-through holes.

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Technique for Making Cards And Boards Repairable

The repair of cards and boards results in a significant loss of copper particularly in the plated-through holes. However, it has been discovered that by the simple application of a coating of electroless nickel (boron, not phosphorus) after all etching has been completed and finally, followed by a thin layer of electroless gold or solder dip will render such card or board plated in this manner capable of sustaining repeated rework without degradation in the plated-through holes.

This technique has been tested with the following results. Several cards were plated with electroless nickel using the boron process. The nickel surfaces revealed excellent wetting. Then, the cards were reworked, and after metallographic examination, the cards showed no evidence of copper dissolution even after twelve (12) rework cycles. These rework cycles involved sixty heatings of the plated-through holes with molten low melt solder. Without the nickel plating, the copper is dissolved or otherwise deteriorated in four rework cycles or less.

Disclosed anonymously.

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