Mechanical shock modeling and testing of lead-free solder joint in hard disk drive head assembly

Solder joint reliability in hard disk drive head assemblies is of great concern due to the increasing demand and popularity of portable electronic products such as mobile hard disk and laptop computers. The mechanical shock resulting from mishandling during transportation or customer usage may seriously affect the solder joint reliability and lead to malfunction of the electronic product eventually. However, little information in detail related to the dynamic responses of the hard disk drive (HDD) cover and suspension, which is closely related with the stress and strain in the solder joints during the mechanical shock, has been reported. In this paper, comprehensive dynamic response of the suspension and the corresponding distribution of stress and strain of the solder joints during the impact process are captured, and it is found that the solder joint failures mainly concentrate at the interface between solder and suspension. The failure mode and location of solder joints simulated by modeling is in good agreement with the mechanical shock experiment.