Solder joint inspection with induction thermography

Defect solder joints on SMD packages can lead to the immediately fail of an electronic device or to instable operation. Apart from electrical conductive tests of the device, there is no appropriate non-destructive evaluation (NDE) method to test the functionality of such solder joints. The paper will present an alternative NDE method based on inductively excited thermography. QFP samples are prepared and test measurements are performed. Parameters like excitation frequencies and possible coil orientations are investigated. The measurements demonstrate that the presented method can be used to test the functionality of solderings. Application limits (e.g. required measurement time) are discussed. This new NDE method is capable of being used as an add-on in electronic manufacturing and failure analysis.