Improving the LMX324 Amplifier IC Testing Process

Abstract

The objective of this research is to improve LMX324 amplifier IC testing process. The testing has to be compliant with the given standard in the document. Eight product characteristic parameters are tested. Each test consists of eight steps and can only be performed on one unit at a time. Three improvement strategies are considered. The first one focuses on the re-ordering the sequence of characteristic parameters to be tested. ECRS and value added activities are utilized to remove non-value added activities (steps involved the same value setting for testing and an unnecessary waiting). The re-ordering reduces testing time by 9.4% per unit. The next strategy tries to increase number of units tested for a given test period – in this case, from 1 to 4 units tested at the same time. In order to do that, new voltage measurement circuits are designed and installed to existing on. Doing so cut testing time by 25.6% per unit tested. The last strategy considered is try to cut down the testing time during voltage measurement of testing step which takes 61% of total testing time due to the fact that the testing step has to measure the voltage over 1,160 times for one test. Dunnett’s test is performed in order to determine the lowest possible number of samples must be taken for the test. Result shows that the test requires 800 and 350 repetitions for 5V and 10V testing with 95% level of confidence. The reduction in the number of samples required greatly cut the test time down by 23.8% per unit. In summary, all the three strategies reduce in total 58.6% of testing time per unit. To further check the variation of result due to the new test procedure in comparison to the original one, GR&R is performed. Result suggests the variation between the new and original testing is satisfactorily less than 5%.