Hello, we are attaching this device to an FR4 substrate and experiencing a small % of failures that appear to be caused by a poor connection to the input pins B3 and C3. We recently cross sectioned a failure to find out what is happening. The picture below shows cross section photo of pin C3 when it is soldered to the board. There appears to be a fracture in the solder joint near the pad of the LMC8101.
My question is regarding the fracturing of the solder joint, is this something that has been seen before and is it known what the causes could be? Some more details about our pad geometry: we have10mil pad sizes and 1 to 2 mils larger mask openings.