Drop impact of a typical portable electronic device

Drop impact reliability is an important concern for the design and use of portable electronic products. When the product is accidentally dropped on the ground, impact forces are transmitted from the product case to the printed circuit board (PCB) and other components within the case. These forces may cause severe functional damage in the form of component failure and/or interconnection breakage. This paper reports our investigation on the dynamic behaviours of a typical portable electronic device under drop impact loading. Firstly, an idealized system which contains an outer case and a PCB attached with a package was adopted as specimen. With an innovative design, the actual impact force pulses were measured by employing a Hopkinson bar in the dynamic test rig. Dynamic strains of the PCB were simultaneously recorded to explore the correlation between the strains and the impact pulse. Particular attention has been paid to the dependence of the shock response of the PCB on the impact velocity, impact force pulse, as well as the impact orientation. Analysis is carried out to explain the experimental results. A deep understanding of the shock response of typical electronic product systems will help to guide the design of rugged and highly impact-resistant devices.