Reflow soldering is very important technics in SMT.Thermal impact to PCBA during reflow soldering is considered one of the main drivers for manufacturing defects.The materials making up a PCBA is various,and the thermal property of the materials is also different ,this may cause some defects for example wargpage.Excessive warpage in the PCB may result in gaps forming between the module leads and the molten solder on the solder pads,then the failure of electronical and physical connection lead to PCBA's defe...