The use of statistical experimental design for PCB process optimisation

Statistical experimental design (SED) can be used as an analytical tool to investigate the effect of a range of PCB processing parameters (variables) on certain final properties (responses). Compared to the “typical” method of carrying out experimental trials, the use of SED can identify “interactions” between variables that may not become apparent without extensive testing otherwise. The SED route also offers a measure of experimental error within the process and can suggest ways to optimise the process, with a reduced number of experimental runs. An application of the SED process is also discussed regarding the evaluation and optimisation of a horizontal liquid photoimageable solder mask (LPISM) spraying process in accordance with certain key factors.