Aluminum sample with parylene coating
Measurement of thickness and n&k of Parylene coating using direct fit of model to measured data
Parylene (p-xylylene) polymers coatings are conformal and pinhole free – they are used as a moisture and dielectric barriers in many applications. There are several types of Parylene polymers: Parylene C, Parylene N, Parylene AF-4, Parylene SF, Parylene HT, Parylene X, etc. All these Parylene types have different chemical and optical properties, so the refractive index can vary significantly depending on the type of the material.
Parylene films are, typically, thick and it is easy to measure their thickness using FFT thick film algorithm, assuming the refractive index (dispersion of the material) is known. This approach does not require accurate calibration or detailed model of the filmstack – it is convenient in production environment. However, if the correct refractive index is not known – the thickness reading will be inaccurate as well. In this case, refractive index dispersion need to be measured first using direct fit to the measured data. After R.I. is determined, thick film (FFT based algorithm) can be used to accurately determine thickness.
MProbe provide a solution for quick, accurate and non-destructive measurement of parylene films directly on the product. On desktop or online.
In case of desktop system, MProbe Vis or MProbeHC are used.MProbeHC is used for large or bended metal sheets that cannot be placed on a sample stage. For online applications, MProbeVis head is integrated with the scanner or multichannel version is used.
Every MProbe system can be customized with specialized reflectance probe, software features and report protocol specific for application requirement. Easy integration with 3rd party software via Modbus TCP based interface is available.
MProbe can measure any other polymer coatings, organic or water based. The measurement method is not dependent on chemical composition but only require translucency of the material.
Why use MProbeVis?