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Article: Solder joint reliability of different BGAs reworked using low melting point Pb-free alloys; Under testing, uniform joint microstructures and reliable joints were observed.(Pb-Free Rework)
- Article from:
- Circuits Assembly
- Article date:
- September 1, 2008
- Author:
CopyrightCOPYRIGHT 2008 UP Media Group, Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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The initial low melt rework investigation was performed in four sequential phases on RIA2 test vehicles. The first phase was an investigation of joint microstructures resulting after rework using three different low melt alloys. Three commercially available alloys were selected (Table 1). Alloys A and C were alloys containing indium, and Alloy B was a Bi-containing alloy.
In this phase, all BGAs on a limited number of RIA2 boards with OSP finish were reworked in air. Hot gas rework profiles were created and optimized for each solder paste. The criteria for rework parameter optimization were proper shape of solder joint after rework, minimized voiding, uniform ...