Fuzzy Model of Failure Evaluation for Printed Circuit Board Products  
Author Kuen-Suan Chen

 

Co-Author(s) Chun-Min Yu

 

Abstract Surface-mounted technology (SMT process) is a crucial technology in the solder paste printing process of printed circuit boards (PCBs). The SMT process offers high stability, low welding defect rates, and good high-frequency properties. It also reduces electromagnetic and radio frequency interference. Thus, improving SMT process capabilities can increase production efficiency, reduce production costs, and stabilize the working environment of circuits, which in turn enables good technical support for subsequent processes. According to some studies, PCBs with severe solder paste misalignment are more likely to malfunction within their warranty period, thereby resulting in losses. The number of product failures generally follows a Poisson distribution; the current paper exploited this characteristic to propose a simple and easy-to-use product failure evaluation index. The proposed index is a function of the process capability index and has a one-to-one mathematical relationship with the product non-conformance rate. First, we derive the confidence interval of process capability index . Based on this, the confidence interval of the proposed index is derived. We then develop a fuzzy failure evaluation model for PCBs based on this confidence interval. The proposed approach assists the electronics industry in monitoring the impact of process capabilities on solder paste misalignment in PCBs. It further evaluates whether product failure rates are controlled within tolerable levels.

 

Keywords Surface-mounted technology; Process capability index; Product failure evaluation index; Confidence interval; Fuzzy failure evaluation model
   
    Article #:  RQD2024-139
 

Proceedings of 29th ISSAT International Conference on Reliability & Quality in Design
August 8-10, 2024