Power Module External Metal Case Thick-Aluminum Wire-Bonding Reliability Technical Research

Comparing to power modules made of other modes. the Thick-film Hybrid Power modules maintains obvious advantages in terms of high performance. high density. small dimension. light weight. and high reliability. it has been widely used gradually in high-end areas as aerospace. astronautics and military telecommunication. The application in these high-end applications thus point out much higher technical requirements with the reliability performance of Thick-film Hybrid Power modules. Among them. the traditional method of achieving electric connection with the Power module external case is by soldering of silver-plated copper wires. However. this mode of soldering has a fatal problem of reliability lowering-down due to circuits working temperature ascending&the soldering material melting. thus it has become a bottle-neck effecting Hybrid Power Module high-reliability achievement. So it is the research that the Hybrid Power Module circuits metal case thick aluminum wire bonding reliability research aimed at replacement of external wire soldering method. which is of significant importance.The paper started from the Hybrid IC wire bonding technology research. with a detailed description of various wire bonding technology. It also introduced the pros and cons of aluminum ribbon bonding. thick aluminum wire bonding. gold ribbon bonding and copper wire bonding. with an analysis of the status and characteristics of Power Module circuits metal case high-current interconnection technology from home and abroad. thus laid a good foundation for the Hybrid Power Module circuits aluminum thick wire bonding test and reliability study.The Hybrid Power Module circuits metal case aluminum thick wire bonding has raised pretty high requirements with reliability. So this research is mainly addressed to Hybrid Power Module circuits bonding jobs with various metal cases. they are ordinary Au-Plated Lead Case. thick Ni-Plated Lead Case. thin Au-Plated Lead Case. And the wire-bonding processing conditions. reliability. applicability and other related characteristics of these metal cases are compared and studies thoroughly by experiments. and the bonding quality closely-controlled by following State and Military Standards. The main experimental equipments are M20-Model Manual Thick Aluminum Wire Bonder by OE. USA. and4000-Model Manual Pull-Strength Tester by DAGE. UK.Through comparing the reliability difference of various external wire bonding technologies. and based on systematic screening verification. the optimum Thick-film Hybrid Power Module Metal Case thick aluminum wire bonding mode has been achieved. and that is the design foundation of this research. During the experiments. we made good use of statistical methods. and selected representative key datum out of a great deal of test results. also we applied simple and direct figure&graph in analysis. thus making the result clear at a glance. Through extensive processing experiments over lots of factors. like bonding wire. screening verification. lead pole dimension. bonding index. bonding quality. we finally summarized with the relevant Design Specification and Processing conditions on Hybrid Power Module IC Metal Case thick aluminum wire bonding. also defined related reliability issues and prohibited processing actions. etc.Based on extensive experiments and research on various major factors effecting thick film Power Module Circuits Metal Case aluminum thick wire bonding. the research has provided valuable reference for enlargement of the processing windows of thick film Power Module wire bonding capacity with greater electric currents.