Motorola Corporation

Rajiv Bajaj

Treliant Fang

Michael P Norman

Lizabeth Ann Keser

Lawrence R Gardner

Paul D Asetta

Li Ann Wetz

James J Wang

A method for preparing a metal surface () for a soldering operation is provided. In accordance with the method, the metal surface is treated with a solder flux () comprising a supersaturated solution of a carboxylic acid.

Simplification of ball attach method using super-saturated fine crystal flux

A wax (13) dissolved in solvent is placed on a semiconductor wafer (12) and made uniform. An assembly is formed by bonding the semiconductor wafer (12) to a submount (17) with a uniform wax layer (14). The submount (17) supports and allows handling of the semiconductor wafer (12) during wafer process steps. The assembly is heated in a vacuum to remove solvent and air trapped in the uniform wax layer (14) thereby minimizing air voids which can cause a non-uniform bond. The assembly is then annealed to reduce stress on the semiconductor wafer (12) induced by differing material thermal expansion rates of the semiconductor wafer (12), the uniform wax layer (14), and the submount (17).

Semiconductor wafer wax mounting and thinning process

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Gilbert, AZ, United States of America

Rajiv Bajaj