Conformal coatings on PCB assemblies range from simple water-soluble dust protection (typically < 20 µm) to specialized hydrophobic coatings (< 1 µm). Test coupons are common, but coupon thickness often differs significantly from the actual product. MProbe Vis-MSP measures coating thickness directly on electronic components - including on SMT element surfaces - to verify uniformity and thickness, which meaningfully improves final yield. Measurement typically uses a 20–40 µm spot on the PCB and ~10–20 µm on top of SMT components, in the visible/Vis-NIR range (400–1000 nm), with up to four objectives and stored calibrations.
Why use MProbe Vis MSP?
- Small-spot measurement is required for direct measurement on PCB assemblies and SMT component surfaces.
- Typical spot size is ~20–40 µm on a PCB and ~10–20 µm on top of SMT components.
- Up to four objectives can be used, with calibration stored for different configurations.
- The camera image and reticle make it easy to navigate to the desired measurement location.
- Results can be displayed directly on the image.
- The 400–1000 nm wavelength range works well for most PCBA coating applications.
Basic specification
| Recommended system | MProbe Vis-MSP |
| 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 | 2–200 µm, depending on objective |
| Imaging | Integrated 2 MP camera to display the measurement area |
| Automation | Custom holders and automation available |
Measured with: MProbe Vis-MSP (MProbe 40).