Breakdown phenomena in power integrated packages

摘要

Tests have been performed on a test pattern designed to study theneffects of applying voltage to the inside of the package. The need tonapply high voltage to the internal connections of the package, withoutndischarges occurring outside the package, has led to the design of anmetal frame having only two leads spaced 16 mm apart. Specimens havingnthree different distances between the bonding pads (60 μm, 100 μm,nand 160 μm) have been prepared. Test patterns for the three kindsnhave been subjected to breakdown tests by applying an increasing 50 Hznvoltage. No meaningful breakdown voltage (BDV) difference appearednbetween the results for each test set, demonstrating that the dischargesnoccur not in the encapsulant, but through the passivation layer.nConsequently, new test patterns having a double thickness oxide layernhave been manufactured in order to stress the encapsulant with a highernfield strength. The discharge test results have shown increased valuesnof BDV, yet no meaningful differences between the BDV of each set havenbeen found, indicating that the discharge path was through the oxidenlayer even with a double layer. The results support the possibility ofnimplementing power plastic packages which work at higher than usualnvoltage by modifying the metal frame