Discrete Device Testing Method Research And Hardware Implementation

In the case of the characters of discrete semiconductor devices can’t be replaced by integrated chips, discrete devices also have broad prospects nowadays when integrated chips develop rapidly. With the big shift of international production, a mass of producers of discrete devices shift into China and national self owned brands is developing gradually. Our semiconductor industry is stepping into a rapid development track. However, mass producing and appearance of new devices also take new standard to the test of discrete semiconductor devices. With the reduction of production costs and expansion of production scale on assembly line, automaticity and test rate of test equipment also require a higher standard. According to investigation, most of our national semiconductor producers import testing equipment, however, there’s few large companies who are engaged in researching of semiconductor testing equipment. In addition, most of semiconductor testing equipments are suitable for devices of only one type and have a low intelligence and automaticity.The integrated test system of discrete semiconductor devices researched in this task is suitable for various devices and can meet the standards of modern automatic test. Users can program test procedure rapidly according to testing requirements. This equipment can accomplish the test of DC parameters and AC parameters of common discrete semiconductor devices and make automatic test and selection through controlling sorting machine on assembly line. The first chapter makes a analysis of the research background and significance. The second chapter analyses the types of electrical parameters of discrete devices and classify these types which lay a foundation to research of test equipment of discrete devices. The third chapter do a research of test methods of AC parameters and DC parameters of common discrete devices and gives the specific test theory and test method of every parameter. Chapter4and chapter5introduce the overall design of hardware which consists of CPU board, high voltage board, low voltage board, pulse current board and test adapter, and clearly introduce the implement principles, design plan and technical data. Chapter6introduces the method of calibration and test of discrete devices test equipment. Finally, the application of the test system and analysis of performance are accomplished by combining with specific test cases.The designed discrete semiconductor testing instrument is of high accuracy, rapid speed, and low cost. It is qualified for the requirement of the semiconductor manufactures to the testing device, and can be extensively used in the factory testing of the discrete device.