Pan Pacific Symposium Conference Proceedings

Solder Paste Printing and Solder Paste Inspection Optimization Strategy for the PCBA SMT Process

Authors: Phil Isaacs, Wayne Zhang, Alec Chen, Hill Liu, and Tracy Cai
Company: IBM and Wistron
Date Published: 2/14/2012   Conference: Pan Pacific Symposium

Abstract: The electronics industry continues to see a rapid rate of miniaturization and constant increase in complexity that presents new challenges in the manufacturing of printed circuit board assemblies. With each new generation of hardware new processes are implemented, or existing processes are enhanced, to assure the quality of the finished product. Solder paste printing and solder paste inspection, SPI, are two such operations that are challenged by each new generation. Both machines are an integral part of the PCBA, SMT production process.

The solder paste inspection equipment was originally introduced with the advent of fine pitch surface mount packages several years ago. Increased complexity of the printed circuit board assemblies creates new challenges to both solder paste printing and solder paste inspection. Due to an unacceptable level of random defects produced by the solder paste printing process, solder paste inspection is required now as much as it was when it was introduced. However, type I errors are often associated with this process where the solder paste inspection equipment designates a defect but there is no defect and this is a false call. This creates production flow issues and a quality problem in manufacturing.

At the beginning of this evaluation, the Solder Paste Inspection, SPI, first pass yield was very low, the yield changed according to the complexity of the product. The fallout included both real defects and false calls. This study through gage R&R studies will focus on reducing the false calls and real defects.

Key Words: 

Solder paste inspection, SPI, Process Optimization, Gage R&R

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