Mixed-signal Testing Testability Study To Potential Quality Study

In the thesis, Motorola's squib control IC MA900797's test procedure is researched. Thechip is one part of squib control circuit system, controlling airbag to squib and can dobuilt-in self-test. It is used by TRW Corporation now, improves Motorola's market inmotor product and reflects Motorola product's excellent ability and reliability.My responsibility is to test MA900797 totally, including open/short, module function,system function. In real production test, I have solved 2 problems: heat reliabilityverification and cut-off crack die defect. After introduction of chip function and heatreliability, the crack die is discussed thoroughly. Crack die in MA900797 is found fromcustom usage. It is a kind of silicon surface defect due to using thinner wafer infabrication. The crack die chip will increase too high and be burned in high temperature.The target of this work is to achieve Motorola's 'Zero Defect' quality and delete custom'spotential danger in usage.The thesis displays the method to solve crack-die problem in airbag squib control chip,which has potential crack-die problem. At first, the thesis verifies the transient thermalreliability in driver transistor by fluid software simulation. In IC assembly test process,the causes inducing crack-die problem are discussed. The crack die dose not affect ICnormal work, but is a potential safety issue in high temperature working. Based onrelation of silicon mass and temperature change during heating by thermal transientcalculation, and ? , the variation of circuit driver transistors forward voltagefrom room temperature to high temperature, are detected as a key feature of crack-diechip and added to test program. The new test program limit can be defined by good/badsamples' experiment results. The final solution is to add and ? test program tomeasure before and after heating and calculate its change value-? in MST(mixed-signal tester) by TPG (test program generator).Vb eVbeVb eVbeVb eVbeThe problem discussion process includes detailed statement of thermal transient analysis,semiconductor IC assembly test, test hardware and software, MST (mixed-signal tester)used by Motorola corporation in manufacture, TPG (test program generator) for MST,and how to write a new test program by TPG..