Open Access

Christoph Reiser, Nicolai Simon, Volker Bucher

• Parylene-C is a multifunctional polymer coating in the coating industry. In medical technology, it is approved for implants due to its biocompatibility. For example, it is used as a coating for electronic components and parts. The problem is that Parylene-C alone is too permeable to body water and the ions that are dissolved in it. Application as a coating material for long-term implants is therefore not possible. The infiltrating water not only corrodes the electronic components, but also reduces the adhesion between the Parylene-C and the coated surface. Therefore, layer systems of metal oxides and polymers are used for encapsulation. The aim of this work is to find out how different layer systems behave in relation to their water vapour transmission. Thicker systems should allow less water vapour to pass through than thinner ones. The task is to find this out using the test method for water vapour transmission barriers and to determine the water vapour transmission rate. It has been proven that in some cases the thicker layers performed worse than the thinner layer systems by a factor of ten. It has been shown that there is a relationship between the base substrate thickness, the thickness of the layer system and their flexibility.