Investigation of Layer Thickness Distribution and Surface Defects on Screen-Printed Magnetic Sheets

Screen-printing allows the production of near net shape, ultra-thin magnetic sheets for electrical machines. This leads to a significant potential for increasing performance or efficiency regarding power density and iron losses in stator cores. This publication investigates the influence of layer thickness distribution and surface defects caused by the screen-printing process and the interaction to the pre-process step iron paste production. The geometric green part properties are systematically analyzed by statistical design of experiment. The factors iron paste, squeegee speed, -pressure and print mode are therefore varied and analyzed regarding the quality targets layer thickness, layer thickness distribution and defects. The aim of the investigation is firstly to determine the main influencing factors and interactions on the target variables and subsequently the derivation of suitable parameter combinations by target variable optimization. Secondly, a data value stream is developed to enable a traceable process chain.