Error modeling in board test

The testing of electronic circuit boards suffers from two types of errors: Type I error occurs when a good circuit board fails the test while Type II error occurs when a defective circuit board passes the test. Both of these errors should be considered in modeling the test process although Type II error alone has traditionally been the focus of test improvement efforts. This paper relates both error types to the defect level and to the level of good circuit boards which fail. Actual board test data is analyzed which indicates that the risk of Type I error may be as great as that for Type II error