Cold Ball Pull Test Efficiency for the PCB Pad Cratering Validation with the Ultra Low Loss Dielectric Material

Cold ball pull testing is used to validate the resistance of PCB pad cratering for the different ultra-low loss dielectrics materials (Dk=3~4.2 and Df <= 0.005 @ 1GHz) in the study. The materials were fabricated in multiple PCB shops using a common test board design utilizing a coupon to result in a 16 mil nominal pad size for the pulls. After fabrication, a 20 mil SAC305 ball is SMT attached to the 16 mil nominal pads for pulling. Each material had 3 coupons with 50 pull locations on each to generate 150 data points for statistical analysis. The peak pull force differences of the material builds can be compared to differentiate the results. As a result, the different ultra-low loss dielectric material’s performance to withstand PCB pad cratering can be compared comprehensively with the cold ball pull test....