Wilfried Sauer

Optimization of quality costs

Abstract The main goals of quality management in all industries are customer satisfaction by delivery of defect-free products and the radical reduction of defect rates and quality costs in the production. Controlled technological processes are the most important way to reach these goals. 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. During the assembly of electronic devices, processes are sensitive to the influences (environmental, parameter variation, etc.), that act on these processes. These influences are very strong, especially in the production of small batches of assemblies and a high mix of products. Processes can become uncontrolled, the defect rates can rise, and it is necessary to have inspection and repair processes after the different technological processes. But what about the quality costs? Is it sensible to do these quality control steps from the economical point of view? What is the right inspection strategy—no inspection or 100% inspection or statistical process control? To answer these questions new simple and powerful quality cost models have been developed at the Electronics Technology Laboratory and are in use in electronic producing industries. The quality costs are the “measurement system” to compare different inspection strategies with each other. The costs are calculated by the use of mathematical models—the quality cost models. To analyze and optimize the quality processes of a complete production line we use the method “Dynamic Programming”, developed by the American scientist, Bellman in the early 1950s of the 20th century.

Machine and process capability coefficient of solder paste printers

For manufacturers of assembled boards seeking ISO 9000 certification, a number of requirements are placed on measurement instruments and tooling. This standard requires a system to document and maintain calibration and machine capabilities. One of these problems is the measurement of printing accuracies of solder paste printers. The paper presents: short theoretical overview of machine capabilities; methods of measurement of accuracies (x, y and rotation); recommendations for the calibration of printers; indications for the sources of inaccuracies; practical examples and results.

Cost Efficient Quality Strategies for Microsystems and Electronics Production

In the last years the authors developed new and powerful quality cost models to optimize quality strategies in electronics production. These models are successful in use and were published in some books (see (Oppermann, 2002), (Sauer, 2003) and (Linss, 2003)), tutorials, articles (see (Oppermann, 2003)) and presentations at important conferences like IWK99, IWK2005, ECTC2001, ISSE2002 and SMT HYBRID PACKAGING 2002, 2003, 2004 and 2006. These models look for the quality processes only to find out the optimized quality strategy by the minimum of costs. The next step was the development of an extension of these models to include the production process and its quality dependent properties into the cost models. The question is: how influences the improvement of a production process by investment the quality and the costs of the products? How much time does it need to reach a better quality level by lower costs? The new extension of the quality cost models gives help to the production engineers to make a decision about the right quality strategy. The basic quality cost model and the influence of investment is explained in this paper

Best quality strategy for electronics production

In the last years the authors developed new and powerful quality cost models to optimize quality strategies in electronics production. These models are successful in use and were published in some books, tutorials, articles (see [Martin Oppermann (2002)], [Martin Oppermann, Wilfried Sauer and Heinz Wohlrabe (2003)] and [Martin Oppermann, Wilfried Sauer, Heinz Wohlrabe and Thomas Zerna (2003)]) and presentations at important conferences like ECTC, ISSE and SMT hybrid packaging. These models look for the quality process only to find out the optimized quality strategy by the minimum of costs. The next step was the development of an extension of these models to include the production process and its quality dependent properties into the cost models. The question is: how influences the improvement of a production process by investment the quality and the costs of the products? How much time does it need to reach a better quality level by lower costs? The new extension of the quality cost models gives help to the production engineers to make a decision about the right quality strategy

Process technology of electronics - a graduate textbook

The Electronics Packaging Laboratory (German abbreviation: IAVT) of Dresden University of Technology is focused on research and education in the field of the production of electronic modules and devices. Together with the Centre of Microtechnical Manufacturing (German abbreviation: Z/spl mu/P), which is also a part of the Department of Electrical Engineering and Information Technology, many projects are realized. Beside this there is also a long tradition and a lot of scientific experiences in process technology, which means all questions of analyzing, describing, modeling, simulating and calculating production processes with special focus on electronics production. A number of lectures are offered. Beginning of 2003 a group of scientists of both the Electronics Packaging Lab and the Center of Microtechnical Manufacturing decided to write a summarized textbook about process technology. Edited by Prof. Wilfried Sauer the book was issued in September 2003. It is useful as a textbook for the different lectures during the main (graduate) study of Electrical Engineering, specialization Electronics Packaging, as well as a summary of the whole scientific field of process technology of electronics.