.png)
On this page (11 sections)
When to use it
Consider coating for products used outdoors, in humid or dusty environments, in vehicles, or in industrial settings with chemical exposure.
Coating is also useful for products that must pass harsh environmental tests.
Types of coating
Common types include acrylic, silicone, urethane and epoxy, each with different protection, reworkability and temperature properties.
The right choice depends on environment, rework needs and cost.
Design considerations
Mark keep-out areas for connectors, test points and switches. Plan masking during design to keep assembly efficient.
Planning in design avoids extra masking work in production.
Inspection of coated boards
Many coatings contain a UV tracer that glows under ultraviolet light, making it easy to check coverage and identify areas that were missed.
Inspection confirms protection is complete before boards leave production.
Rework after coating
Acrylic coatings are relatively easy to remove for rework. Epoxy coatings are hard and difficult to remove. Choose based on the likelihood of repair.
Planning for rework helps reduce repair costs later.
Application methods
Coatings can be brushed, sprayed or dipped. Brushing suits small batches and touch-ups. Spraying gives even coverage on larger batches. Dipping coats the whole assembly and requires careful masking.
The method is chosen based on volume, board design and coating type.
Thickness and coverage
Coating thickness affects protection and must be controlled. Too thin may leave gaps; too thick may crack or trap stress.
Thickness is checked during inspection to ensure consistent protection.
Cost impact
Coating adds material, masking and inspection time. For many products the improved reliability more than offsets the cost.
Fewer field failures and returns often justify the additional cost.
Should you coat your boards?
If your product faces moisture, dust, chemicals or wide temperature swings, coating is usually worthwhile. Ask us for a recommendation based on your application.
We can assess your application and suggest the most suitable coating.
Masking
Connectors, switches, test points and some components must stay uncoated. Masking with tapes, boots or liquid masks protects these areas during coating.
Accurate masking ensures connectors and controls continue to work after coating.
Curing
Coatings cure by air drying, heat or UV light depending on chemistry. Curing time affects production throughput.
Proper curing is essential for the coating to provide full protection.