Abstract: Based on the problem of the broken pins of the intelligent power module used in air conditioning device controllers, the failure mechanism research of automobile electronic components was carried out by the method of combining experiment and simulation. First, through the vibration durability test analysis of the electronic controller assembly, the failure of the intelligent power module was reproduced, and the failure was consistent with the failure of the fault sample. Secondly, the method of combining dynamic test and CAE simulation was adopted. The failure of the intelligent power module is mainly caused by the stress, which is caused by the first-order modal resonance of the printed circuit board, and the weak point of the electronic controller assembly is located. Then by adding the screw fixing position of the printed circuit board to the electronic controller assembly, the vibration response characteristics of the printed circuit board are optimized. It is verified by CAE simulation that the stress of intelligent power module is reduced from 301.3 MPa to 51.8 MPa. After the vibration durability test, the function of the electronic controller assembly is normal. The intelligent power module is also checked by X-ray, and the pin of the intelligent power modules were not damaged. Finally, the solution was used to complete the modification design, and provided design guidance for the subsequent reliability design of air conditioning device controllers.

Key words: Air conditioning device, Electronic controller assembly, Intelligent power module, Vibration durability, Design for reliability, CAE