MTE Solutions Conformal Coating Masking Dots/Discs Rubber Adhesive Discs, 1 ML Variety of Sizes
MTE Solutions Conformal Coating Masking Dots/Discs, Polyester Film, Rubber Adhesive, 1 Mil, Variety of Sizes
MTE Solutions conformal coating masking dots are die-cut discs made from yellow polyester film with a rubber adhesive backing, specifically engineered for masking during conformal coating, wave soldering, and powder coating processes. Unlike silicone-adhesive polyimide dots, these discs use a rubber adhesive that is silicone-free — a critical requirement for conformal coating applications where silicone migration into components or onto PCB surfaces can cause adhesion failures and coating defects. Rated for 0°F to 266°F (130°C), they withstand the temperatures of conformal coating cure ovens and wave solder processes. A direct alternative to Hisco conformal coating masking dots. Available in 3/16", 1/4", 5/16", and 3/8" diameters.
Sold individually by size (select diameter above). Custom sizes available on request.
Specifications
| Brand | MTE Solutions |
|---|---|
| Material | Polyester film, yellow/clear liner |
| Adhesive | Rubber (silicone-free) |
| Backing Thickness | 1 mil (ASTM D-3652) |
| Total Thickness | 2.5 mil (ASTM D-3652) |
| Adhesion to Steel | 35 oz/in (ASTM D-3330) |
| Tensile Strength | 16 lbs/in (ASTM D-3759) |
| Elongation | 100% (ASTM D-3759) |
| Dielectric Strength | 4,500 volts (ASTM D-149) |
| Operating Temperature | 0°F to 266°F (0°C to 130°C) |
| Available Diameters | 3/16", 1/4", 5/16", 3/8" |
| Comparable To | Hisco conformal coating masking dots, Kapton tape conformal coating masking discs |
| Application | Conformal coating masking, wave soldering masking, powder coating masking, PCB component protection, control panel masking |
Frequently Asked Questions
Why are these conformal coating dots silicone-free, and why does it matter?
Silicone is a known contaminant in conformal coating and PCB assembly processes. Even trace amounts of silicone on a PCB surface can prevent conformal coating from adhering properly, causing fish-eye defects, delamination, and coating failures. Silicone-adhesive tapes and dots — including standard polyimide masking dots — can transfer silicone to the board surface during processing. These rubber-adhesive conformal coating dots are silicone-free, eliminating this contamination risk and making them the correct choice for conformal coating masking applications.
What is the difference between these conformal coating dots and the polyimide masking dots?
The key differences are the film material and adhesive type. Conformal coating masking dots use polyester film with a rubber (silicone-free) adhesive, rated to 266°F — optimized for conformal coating and wave solder temperatures with no silicone contamination risk. Polyimide masking dots use polyimide film with a silicone adhesive, rated to 500°F — better for higher-temperature applications like powder coating cure ovens, but not recommended where silicone contamination is a concern. For conformal coating processes, always use the rubber-adhesive conformal coating dots.
What sizes are available and how do I choose the right diameter?
Available diameters are 3/16", 1/4", 5/16", and 3/8". Choose a diameter that fully covers the feature you need to mask — connector pins, test points, gold contacts, or component leads — with a small overlap onto the surrounding board surface to ensure a complete seal. Custom sizes are available on request for non-standard masking requirements.
Are these a direct replacement for Hisco conformal coating masking dots?
Yes. MTE Solutions conformal coating masking dots are a direct functional alternative to Hisco conformal coating masking dots, using the same polyester film and rubber adhesive construction. Contact us if you need a specific size not listed or require custom shapes.
