A comparison of two board level mechanical tests-drop impact and vibration shock

Abstract

Accidentally drop induced board level intercom-nects break has become one of the most important failure modes for portable electronic products. Board level drop impact test is widely used to evaluate the mechanical shock reliability of electronic assembly interconnects. In this paper, PCB responses during drop impact and vibration shock are compared using strain measurements. The loading similarities and differences of two mechanical shock tests are analyzed. The possibility and limitation of using vibration method for evaluating drop impact reliability are discussed. Results show that vibration test could be a replacement or supplement for drop test for single mode dominating situation. Vibration shock could produce similar loading amplitude and frequency to that of drop impact by adjusting to appropriate vibration parameters,. Compared with drop tests, vibration test provide better repeatability, easier operability. However, loading similarities between two methods only appear at impact locations dominated by single mode. For the locations with different modes superimposition, vibration shock cannot produce desirable loading as drop impact.