In situ temperature measurements of PQFPs during infrared reflow

Temperature measurements using thermocouples are made at several locations on J‐leaded plastic quad‐flat packs and printed wiring boards during the reflow soldering process. Both moisture saturated and dry packages are studied, with little difference found in the measured temperature on the package surfaces. The temperature at the component lead is found to be a good approximation to the temperatures observed near the die. This provides an externally measurable parameter to assess delamination and popcorning.