关键词: 铜带缠绕型焊柱, 温度循环, 随机振动, 装联结构可靠性

Abstract: The thermal mismatch caused by the large difference in the thermal expansion coefficient between the ceramic substrate and the printed circuit board, and the decrease in anti-vibration performance caused by the large size and high quality are the main reasons for the failure of this type of device board cascade assembly. In this paper, the failure mode and failure mechanism of the solder joints of the copper tape-wound solder column CCGA board cascade structure under the temperature cycle and random vibration load are studied. The results show that the maximum stress and strain point appears at the edge of the copper strip at the contact interface between the copper strip and the solder column, and the crack propagates inward along the cross section of the solder column in the direction of the copper strip winding and eventually leads to cracking. Due to the large difference in the elastic modulus properties of the copper strip and the solder column material, there is a stress mutation phenomenon at the contact interface of the copper strip and the column core. During the long-term use of the device, the solder column and the copper tape will peel off and lead to interconnection failure. Therefore, the selection of copper strip material and the quality of copper strip and column core winding are the keys to the high-reliability application of copper strip wound welding columns. And the good metallurgical interconnection between the copper strip and the solder column and the sufficient solder filling of the copper strip gap are the main ways to effectively improve the thermal/mechanical properties of the copper tape wound solder column.

Key words: coppertapewoundweldingcolumn, temperaturecycle, randomvibration, reliabilityofassemblystructure