In assembling components to a printed circuit board (“PCB”) such as a motherboard, surface mount components, such as ball grid array (“BGA”) components, are reflow soldered to the top side of the PCB. Other components, such as through hole components, are then soldered to the PCB by a wave solder process. This wave solder process heats the bottom side of the PCB, since hot solder contacts the bottom of the PCB.
This heat travels from the bottom side of the PCB to the top side of the PCB through via holes in the PCB. Enough heat may reach the top side of the PCB to melt solder balls in the BGA array and cause a failure of the electrical connection between the BGA component and the PCB.