ULTRASONIC SOLDERING OF ALUMINUM HEAT EXCHANGERS.

A fluxless soldering process is described which was specifically developed for the tubular joints in an all-aluminum tube/fin type air conditioner coil. The process is based on the application of ultrasonic vibration energy to a heated vessel containing molten 95% Zn-5% Al solder filler metal. The step-by-step processing of a coil by this method is outlined, and the critical areas of process control and soldering vaaiables are discussed. The equipment necessary for a production soldering line is indicated.