A guideline for using experimental design mathematical modeling in welding of coil lead frames

A current general need within industry is to utilize statistical methods including experimental design in the development of new processes and their parameters. This need is even more evident in microjoining (small scale resistance welding) due to the number of process variables. This paper outlines an application in which statistical methods are applied to a microjoining process. The paper documents the methodology used to establish optimized process parameters for in microjoining of an electrical lead frame design. The methodology includes utilizing experimental design to develop a linear mathematical model of the process. A preliminary (screening) as well as final design of experiment is performed using a HF inverter and capacitive discharge welding equipment. The validity of the model and its linear assumption are evaluated and a transformation is performed to ensure linearity. Once the regression model has been verified, an optimization is performed to maximize the response variable and determine the optimum process parameters.