Membrane behaviour of Parylene C as housing material

Investigation methods on polymer encapsulation were implemented to determine the quality of a polymer coating on electronic devices against migration and diffusion. Therefore the major goal was to evaluate a membrane of Parylene C clamped in a frame. Two different fluids in chambers on each side of the membrane, bi-distillated water and water with solute salt, generate concentration gradient. The potential drop drives ions through the membrane. With the analysis of the conductivity in the chamber with bi-distilled water the transmission rate of the molecules can be determined in dependence of mass and thickness to area and time. These tests have shown a coefficient for the transmission rate of NaCl. The inspection with the scanning electron microscope as well as measuring the surface roughness conducted to first information about thin Parylene C layers.