Investigation of die-attach degradation using power cycling tests

Abstract

This article describes a complex measurement and simulation based characterization method of high current IGBT modules. The method begins with thermal transient tests aimed at the investigation of the thermal behavior of the module and the creation of a thermal map of the heat conduction path using structure functions. This information can later be used for different purposes, such as the calibration of a detailed thermal simulation model of the system or as a reference for later power cycling reliability tests. During this test the degradation of the die attach layer as a result of power cycles is tracked as it is indicated by the structure functions. In the article we demonstrate the steps of this method with a detailed case-study.

A Review on IGBT Module Failure Modes and Lifetime Testing

“…A more insightful method to track degradation in the thermal path is through the estimation of the structure function of the package [101][102][103][104][105][106][107][108][109]. Fig.…”

“…However, at high bond wire aspect ratios, bond wire lift-off is the dominant failure mode in Sintered group while solder degradation is the dominant failure mode in Soldered group. In another study [101][102], two tests were conducted on standard IGBT modules under constant heating current mode. In the first test, IGBT modules were in active mode and were subjected to a heating current of 25 A, initial power of 200 W, initial ΔTj of 100 °C, ton of 3 s, and toff of 10 s. Under these test conditions, IGBT modules' failures took place after about 35000 cycles and were attributed to die attach degradation as given by structure function results shown in Fig.…”

High performance accelerated test methods for reliability and life time analyses of power electronic packages

“…In the course of this power modules must be protected against fatigue. In particular these high stresses affect the reliability of modules and therefore the life time [1] [2]. The determination of the lifetime of an application is not only costly, but very time consuming.…”

Transient Thermal Characterization for GaN HEMTs with p-Type Gate

“…The deterioration of die-attach between a chip and a base plate for power cycling stress can be evaluated as the variation of structure functions. [2] Structure function can also identify the differences in heat transfer capability between Al2O3 (Aluminum Oxide) and AlN (Aluminum Nitride) used as insulating substrate of DBC (Direct Bond Copper) in power modules. Evaluation of the TIM, which is used between a lead frame and a cold plate, is a common application of structure function as well.…”