Conformal Coating Thickness & Standards Guide

Written by HumiSeal Editor | Apr 20, 2026 11:05:39 PM

What is the typical conformal coating thickness? Liquid coatings such as acrylics, urethanes, and silicones commonly target 25-75 µm dry film, while parylene is typically 5-25 µm. Final targets depend on chemistry, environment, and reliability requirements. Verify against applicable standards, the product TDS, and customer or OEM specifications.

Conformal Coating Thickness & Standards Guide

Engineers often need a fast, vendor-neutral reference for typical dry-film thicknesses by chemistry and for the most commonly cited standards in specifications and validation. Use the tables below for planning only, then set final targets from the product Technical Data Sheet (TDS), customer documentation, and OEM requirements.

Important note: The ranges below are planning ranges, not specifications.

Typical dry-film thickness by chemistry

Chemistry	Typical range (µm)	Notes / when to choose
Acrylic (AR)	25-75	General purpose; easier rework; broad usage.
Urethane (UR)	25-75	Strong chemical and solvent resistance.
Silicone (SR)	25-100	Useful for thermal cycling and vibration; wider thickness window.
Parylene (XY)	5-25	Ultra-uniform thin films for dense assemblies and high-reliability coverage.

UV curable coatings: These are usually applied between 60 and 130 microns dry thickness. In automotive, the range is between 80 and 110 microns dry thickness.

*Planning ranges only - do not use as a specification. Set final targets per product TDS and customer or OEM requirements.

Standards at a glance

Standard	What it is	Common uses / notes
IPC-CC-830	Current industry qualification	Most modern specifications cite this.
MIL-I-46058C	Legacy qualification	Still referenced historically in some workflows.
NASA low-outgassing	Materials for space / vacuum	Validate case by case.
UL 94 flame class	Material flammability classification	Program-specific; confirm per module and material.
UL (file-specific)	Safety, electrical, or flammability recognition	Confirm the exact UL file and Conditions of Acceptability for the application.

Measurement and verification tips

Use a wet-film gauge for liquid coatings and map thickness at edges and tall features; confirm dry-film thickness at critical points.
Log targets, tolerances, and measurement points for audits, and capture edge or feature coverage photos where feasible.
Re-verify thickness and coverage after any change to valve type, overlap, path, or other recipe variables.
Store thickness maps, edge-coverage images, adhesion method and results, and acceptance criteria in the PPAP package.

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