Recently Sebastien Buchwalder, student of Prof. Juergen Burger at University of Bern presented interesting results of his work on new parylene multilayer in Fukuoka in Japan at the 37th International Conference of the Polymer Processing Society. Sebastien has been working since 2019 together with Coat-X on new deposition technologies for Parylene multilayer coatings and on advanced coating characterization techniques. He is developing ultra-low permeability solutions with better thermal stability for highly demanding markets like aerospace, space, and high power electronic using a new deposition process. His project is part of a PhD thesis and of our long-term collaboration with the University of Bern and the Center for Translational Medicine and Biomedical Entrepreneurship.

Using X-Ray diffraction, differential scanning calorimetry, helium transmission and water vapor transmission rates, Sebastien analyzed the stability of crystalline domains, polymer phase transformations and the gas permeation through various types of Parylene (N, C, VT4 and AF4) produced at Coat-X. With the X-Ray analysis, he could demonstrate significant Parylene crystalline growth in Parylene-N and -C thin films above 100°C, and the stability of the fluorine-containing types of Parylene. On the other hand, exceptionally low permeation rates (Helium and water vapor) were measured for Parylene-C up to 200°C. For more elevated temperature (300°C) Parylene AF4 coatings exhibited better barrier properties, and for this material, exposure to elevated temperature reduced the permeation rate.

The characterization of a new Parylene multilayer coating demonstrated the ultra-low permeation rate of this kind of coating, taking advantage of both polymer and ceramic materials. The water permeation of the new technology is indeed many orders of magnitude lower than even five-time thicker Parylene films.

With some more research and thanks to Sébastien, Coat-X will add this new technology of parylene multilayer to its portfolio of conformal coating service, as a new packaging solution to protect for the extremely long-term high added value devices, very sensitive materials and components.

We warmly thank the University of Bern and Prof. Juergen Burger for this exciting collaboration and are looking forward to seeing more such outstanding outcomes!