Process for in-situ warpage monitoring during solder reflow for head-in-pillow defect escape prevention

A method comprising:

• providing a reflow oven comprising one or more heating zones;
• positioning one or more monitoring devices along the reflow oven, wherein a first monitoring device is positioned at an inlet of the reflow oven, a second monitoring device is positioned at a heating zone of the reflow oven at which a product reaches a peak reflow temperature, and a third monitoring device is positioned at a cooling zone of the reflow oven;
• receiving, at a processor, a warpage measurement of the product from the one or more monitoring devices as the product passes through the reflow oven;
• comparing, by the processor, each warpage measurement to a predetermined warpage limit;
• and
• sorting, by the processor, the product into one of a plurality of designated lots based on the comparison.