Drop/impact tests and analysis of typical portable electronic devices

Drop/impact protection is an important concern for the design of portable electronic products. Drop/impact forces may cause severe functional damage in form of component failure and/or interconnection breakage. This paper presents our investigation on the dynamic behavior of typical portable electronic devices under drop impact loading. First, an idealized system which contained an outer case and a Printed Circuit Board (PCB) with an attached packaged chip was adopted as specimen. The actual impact force pulses were measured by employing a Hopkinson bar in a dynamic test rig. Dynamic strains at several locations of the PCB were simultaneously recorded to explore the correlation between the dynamic strains and the impact force pulse. Particular attention was paid to the dependence of the dynamic response of the PCB on the impact velocity, the force pulse, as well as the impact orientation. A simplified analytical model is proposed to interpret the experimental results. Technical measures are suggested to guide the design of the relevant devices with better drop/impact protection.