Pad voiding: If you can’t avoid it, measure it!
Component manufacturers know that not every single defect is reason for discarding or even reflowing a board. As a matter of fact, most components have a well-defined percentage of acceptable failure. Pad voiding is a perfect example of this scenario. For every component, there is a very specific threshold provided by the manufacturer. Our TruView™ Void analysis software utilizes these parameters to calculate voiding and determine a pass/fail status. The image below shows a live x-ray image acquisition side by side to a void analysis.
We used the TruView™ Fusion x-ray inspection machine to analyze a LED for voids. The results were incredible! The process is very straight forward; our custom algorithm automatically defines and locates the regions of interest (ROI) and adjusts the threshold to find the voids in each pad. Results are updated in real time. In the case of this pad analysis, the total void percentage was 13.33% with the largest single void measuring 6.17%. We then used the Render 3D feature of the TruView™ software to better visualize the defect. The visualization helps us understand potential conductive and thermal issues.
Issues like pad voiding will be around up until we start manufacturing inside vacuum tubes! Until then, the best we can do is use non destructive testing like x-ray inspection to identify and analyze voiding issues to stay one step ahead of product failure and RMAs.
Check our white paper on LED void analysis at X-Ray University.