Method and apparatus for testing lead connections of electronic components

摘要

To test the quality of solder bonded lead connections of a package by applying a shearing force to the leads using ultrasonic vibration and by measuring the resultant strain. A probe 32 is pressed against the surface of a lead 12 and vibrated by a piezoelectric element 38 in parallel with the lead surface to apply a shearing force to the solder bond portion. The resultant strain occurring in the solder bond portion is correlated with current and impedance of the piezoelectric element 38. By measuring the current and/or impedance of the piezoelectric element, the quality of the solder bond portion can be determined. Thus, a circuit board is produced having solder joints whose maximum strain in reaction to load is limited by the amount exhibited by a good joint.