Authored By:
Jim Bielick, Brian Chapman, Mitchell Ferrill
Michael Fisher, Phil Isaacs, Eddie Kobeda, Theron Lewis
IBM
Summary
Very large high thermal mass surface mount connectors are difficult to rework. This paper examines the difficulties of reworking a very high thermal mass, high density, 5040 lead count surface mount connector. As we approached this problem it was clear that the rework equipment available did not have the power required to perform this rework in an
acceptable process window.
A multi-functional team was assembled to develop, execute and qualify the connector rework process. This paper describes the special equipment selected expressly for this process: Localized vapor phase reflow tool, site redress process, selective site solder paste printing process and the quality control processes.
To assure success multiple paths were developed in parallel. The local vapor phase process came out clearly superior to alternative processes, and was established and qualified within a few months. The process was verified through mechanical measurements, cross-sections, high-resolution X-Ray and stress testing and results met all requirements.
Initially Published in the SMTA Proceedings
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