Quality control in capacitor production and testing

The properties of materials and the appropriate dimensions must be controlled so that the requirements of the electrical specification are met from the beginning of the life cycle of the product. The influence of design on control of manufacture is discussed and the factors which contribute to variability in production are examined. The main quality control function is to establish a `right first time¿ philosophy. While the concept of yield is inevitable in component manufacture, low yield due to lack of control is unacceptable. In-process inspection with feedback for corrective action not only maintains control but also points the way for continuous improvement of design, methods, quality and reliability. In some cases the involvement of the production operator can be obtained by allowing him to carry out this checking. Acceptance and quality assurance testing are of primary importance in demonstrating to the customer that the requirements of his specification have been met. Failures in this testing are warnings of lack of control in design, materials, or manufacture. The BS 9000 scheme is welcomed as establishing a systematic series of such tests. From the internal point of view total quality costs are the best method of measuring the performance of the entire manufacturing organization. If the quality control function is effective, and assuming no radical changes of product mix, quality costs should be falling. From the external point of view an effective quality control organization is the best assurance of consistent performance for the future.