;Introduction of SMT patch production characteristics.

As the last process of SMT production process, reflow soldering combines the defects of printing and surface mounting, including less tin, short circuit, side stand, deviation, missing parts, multiple parts, wrong parts, reverse direction, reverse side, erection, cracks, Weld bead, void and gloss, among which erection, crack, weld bead, void and gloss are.

　　 Erection: The phenomenon that one end of an electronic component leaves the pad and tilts or rises.

　　 Tin connection or short circuit: The solder joint connection occurs between two or more unconnected solder joints, or the solder of the solder joint is poorly connected to adjacent wires.

 　　Empty soldering: An assembly phenomenon in which the solderable end of a component is not connected to the pad.

　　 Reverse: The direction is wrong when the polar component is installed.

　　Parts error: The model and specification of the part installed in the specified position do not meet the requirements.

　　 Few parts: The material is not installed where the parts are needed.

　　Exposed copper: The green oil on the surface of the PCBA is peeled off or damaged, and the copper foil is exposed. 

 　　Bubble: PCBA/PCB surface is deformed due to area expansion.

 　　 Tin hole: After passing through the furnace, there are pores and pin holes on the solder joints of the components.