Protective Polymer Coatings

Sensitive electronic components and sensors, technical medical products or membranes are often covered by polymeric coatings to protect them from aggressive media, to increase their biocompatibility or to form a specific barrier layer.

In the case presented here, a circuit board should have been protected with a film made of the polymer Parylene for mechanical stability and corrosion protection. When the failure rate for the components increased the question was raised whether the several micron thick film on the surface of the board actually consisted of the desired polymer or was accidentally replaced by different product. An ATR-IR analysis of the unknown protective coating was compared to the spectrum of a Parylene reference to resolve this issue.

The presented infrared spectra show unambiguously that all absorption bands are corresponding. Therefore, the needed protective coating was clearly identified as Parylene and an accidentially use of a differnt material could be excluded as the cause of the increased component failure.