A million frames hold the new Domesday

test (DUT) is loaded into one of many sockets con- nected to a double-sided printed-circuit board (PCB). The DUT board is then placed inside the oven and automatically con- nected to a back plane connector, to which various test function in- structions are applied. These include power supply, clock pulse data and external monitoring facilities, and are con- trolled by three plug-in cir- cuit cards. The program card is used alone when static burn-in is the sole requirement. The card routes power and static sources to the appropriate connecting pins of the DUT and con- trols the temperature of the oven as set by the user. The clock card in- cludes all the functions of the program card but in- cludes too the application of clock pulses, tempera- ture cycling and load vari- ations. The monitor card is used when the user wishes to compare the dynamic performance of the DUT with that of a reference device, known to be of faultless performance, that is mounted on the pro- gram card. Any ...