Process plug for ultrasonic soldering

摘要

An improved process plug for use during immersion soldering of aluminum heat exchanger coils, such as an air conditioner evaporator. The plug allows the solder to flow into an open bell or female socket of a suction header tube to "pretin" the internal finish of the bell or tube joint while preventing the solder bath from entering the coil. The process plug is designed to achieve a "short" or reduced area joint so that the plug can be readily removed by heating. The suction header tube joint is completed by hand soldering of a precoated male copper transition tube.