ANALYSIS AND OPTIMIZATION OF MANUFACTURING AND TEST PROCESS ARRANGEMENTS WITH NEW COST MODELS
Author: Martin Oppermann Company: Dresden U. of Technology Date Published: 9/12/1999
Abstract: The main goal of quality management in all industries is customer satisfaction, the radical reduction of defect rates and also of quality costs. Controlled technological processes are the most important way to reach this goal. These principles are standard in mechanical engineering and are in use with great success. The properties in electronics production are different from the properties in mechanical engineering. The processes are difficult and many environmental influences act on these processes. These influences are very strong, especially in production of small batches of assemblies (solder paste printing, placement and soldering process). Some processes are not controlled and the defect rates are increasing. What can we do with these processes? A 100% test of PCBs must be carried out after the difficult process. But what about the quality costs? Is it sensible to do this test with a view to the costs? To answer these questions easy to use new and powerful quality cost models have been developed. They com-pare the costs with and without a test after a technological (manufacturing) process. The qual-ity cost models are based on engineering thinking. The consideration of the escape and the pseudo defect of test processes and SPC are also part of the models. In order to be able to apply these models, we developed software tools which can give a decision aid in test process organization.
The investigations were made in cooperation with electronics production of a big international machine building enterprise. In our presentation the basic quality cost models will be explained. The implementation, the successful use and the results of using these models will be shown and the direct effect of using these models to decrease the costs and to improve the controlling of the difficult processes will be presented.