Parylene (p-xylylene) polymer coatings are conformal and pinhole-free, used as moisture and dielectric barriers. Several types - C, N, AF-4, SF, HT, X - have different chemical and optical properties, so refractive index varies with type. Parylene films are typically thick, so the FFT thick-film algorithm measures thickness easily when the refractive index is known - convenient in production, needing no accurate calibration or detailed model. If the refractive index is unknown, it is first measured with a direct fit to the data, after which FFT gives accurate thickness.
MProbe measures parylene directly on the product, on the desktop or online. Desktop work uses MProbe Vis or MProbe HC (for large or bent metal sheets that can't sit on a stage); online work integrates the Vis head with a scanner or a multichannel version.
Every MProbe system can be customized with specialized reflectance probes, software features and report protocol specific to the application. Easy integration with third-party software is available through Modbus TCP.
Why use MProbe Vis?
- Quick, reliable and non-destructive measurement of parylene films directly on the product.
- Economical system with a long-lasting light source.
- User-friendly, robust TFCompanion software.
- The 400–1000 nm wavelength range is well suited for these polymer-coating measurements.
Basic specification
| Recommended system | MProbe Vis; MProbe HC for large or bent metal sheets |
| Wavelength range | 400–1000 nm |
| Wavelength resolution | < 2 nm |
| Precision | < 0.01 nm or 0.01% |
| Accuracy | < 1 nm or 0.2% |
| Measurement time | < 100 ms typical, depending on sample reflectivity |
| Spot size | 1 mm |
| Stage/probe | Universal sample stage with focusing lens and fine adjustment, or a customized probe |
Measured with: MProbe Vis / MProbe HC.