Soldering

A flux unit for applying flux to precise areas of printed circuit boards comprising

• a flux sprayer for applying flux to the printed circuit boards, the flux sprayer including an air valve, a flux valve, and a controller coupled to activate and deactivate separately the air valve and the flux valve, the controller activates the air valve before activating the flux valve and deactivates the flux valve before deactivating the air valve,
• a rough part locator that roughly locates the printed circuit board within the flux unit, the rough part locator including a stopper arm having an end that provides a datum point and a pusher arm for pushing the part against the stopper arm, and
• a precise part locator that precisely locates the printed circuit board, the precise part locator including a datum bushing and a slotted bushing on the printed circuit board, and a datum pin and an expansion pin for respectively engaging the datum bushing and the slotted bushing.