Browse Prior Art Database

Plastics Surface Treatment

IP.com Disclosure Number: IPCOM000060655D
Original Publication Date: 1986-Apr-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Karr, PC: AUTHOR

Abstract

It has been found that EMC requirements for plastic housings, used, for example, in microcomputer systems units, can be most efficiently achieved by plating.

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Plastics Surface Treatment

It has been found that EMC requirements for plastic housings, used, for example, in microcomputer systems units, can be most efficiently achieved by plating.

Some plastic materials have dispersed particles or focal points which can be subjected to selective attack and pit formation into which the plated metal can interlock and adhere. Others, such as polycarbonates and rigid urethanes can not be treated in this way. However, these materials can be pre-treated by a process which attacks, but does not soften the surface and creates crazes on the surface. These crazes are crack-like defects which are load bearing because the opposite surfaces are joined by fine fibrils of highly oriented polymer. The pre- treatment is controlled to prevent progression of the crazes to cracks leading to mechanical failure.

In one example, a reactive injection molded rigid urethane component was subjected to 1, 3 dichloroisopropanol and appropriate wetting agents in an aqueous medium for a time sufficien cause surface crazing. The surface was then subjected to an oxidant, such as chromic acid, to produce polar groups on the surface. The component was then subjected to an electroless copper plating step. The crazes provided mechanical interlocking adhesion and increased surface area, and the polar groups allowed wetting by the plating solution and developed chemical bonds with the plated copper to provide long life high energy adhesion. The process was comple...