Study on acceleration life test method of thick film hybrid integrated circuits

In order to establish an accelerated life test method for thick film hybrid integrated circuits (HIC) and obtain its lifetime data, the accelerated life experiment of medium power thick film HIC was carried out, and the experiment results were summarized and analyzed. Based on the analysis of influencing factors of thick film HIC reliability, and the time-temperature regression in table 1 of mil-std-883h method 1015.10, three groups of comparative experiments were conducted in combination with the characteristics of the product. Group 1 is the test requirement in the detailed specification and is the comparison benchmark between group 2 and group 3.The difference between group 2 and group 3 is the different load. After high temperature burn in test, the degradation of thick film HIC would be accelerated and the sample failure would be caused. Failure analysis showed that high temperature burn in test can induce Au4A1 and in Kirkendall void in Au/A1 bonding system, in the following steady state life experiment, with the continuous production of Au4A1 and the Kirkendall void expanding, bonding wire contact resistance increases, eventually the bonding wire of triode V2 in the sample produced strength failure, caused PWM lose power supply, which made the sample output failure. All these fail samples are in the same group, it implys that worst experiment condition can speed up the degradation of thick film HIC, thus it is recommend that the case temperature should not exceed 125°C during the operation condition.