Strain Gauge Data Can Be Misleading | Predicting Strain Levels Caused by Mounting PCBs in Housing Using the ICT Analysis Feature of Sherlock

PCBs used in automotive applications must be protected from a harsh environmental conditions such as chemical exposure, vibration, heat, cold and mechanical shock. While protecting delicate electronics from these environmental hazards, a housing, if not properly designed will apply sufficient forces to the PCB to damage components. If the damage is catastrophic end of line testing may capture the failure. If the assembly is only wounded, there is increased potential for latent field failures. As component manufacturer’s shrink package sizes it is becoming more difficult to accurately measure component and solder joint strain using conventional strain gauges. By using the ICT analysis function in Sherlock one can estimate the strain levels of components and solder joints. 

The talk will include cross section images of solder joint failures on BGAs, QFNs, and QFPs caused by housing induced strain. Results of actual strain gauge measurements indicating low strain levels will be compared to a Sherlock analysis which predicted unacceptably high strain levels.