Types of Conformal Coating

Selecting the Right Conformal Coating

 

Conformal coating is a specialised polymeric film used to protect Printed Circuit Boards (PCBs) and electronic components against damage due to moisture, dust, chemical and temperature extremes. Additionally, it provides increased dielectric resistance and operational integrity.

With many types of conformal coating to choose from, how to select the right option for your production line?

It mainly depends on the type of protection required, followed by application method and ease of removal. Below are 6 main types of conformal coatings, each with its distinct advantages and disadvantages.

Acrylic Resin

Provides basic entry-level protection due to their low cost and protection against a broad-level of contamination. Our Techspray Fine-L-Kote AR Conformal Coating is ozone friendly too!
Advantages Disadvantages
  • High Dielectric Strength
  • Fair Moisture and Abrasion Resistance
  • Fair Elasticity
  • Easy to Apply and Remove
  • Low Solvent Resistance

Silicone Resin

Provides excellent protection in extreme temperature ranges which is ideal for high humidity environments, like outdoor signages. Due to their rubber nature, silicone coatings are resilient against vibrational stresses but are not abrasion resistant. Techspray Fine-L-Kote SR Conformal Coating is UL94 V-0 rated and meets/exceed MIL-I-46058C Type SR and IPC-CC-830B. 
Advantages Disadvantages
  • Good Chemical, Moisture and Salt Spray Resistance
  • Very Flexible
  • Resilient Against Vibration Stress
  • Low Abrasion Resistance
  • Difficult to Remove

Urethane (Polyurethane) Resin
Commonly used for aerospace applications where exposure to fuel vapors is a main concern.
Advantages Disadvantages
  • High Chemical, Moisture and Abrasion Resistance
  • High Solvent Resistance
  • Difficult to Remove

Epoxy Resin

Available as a two-part compounds and creates a very hard coating which is ideal for potting compounds. In contrast to traditional conformal coatings, epoxy-based coatings completely cover electronics in a solid and level layer of material.
Advantages Disadvantages
  • Good Humidity Resistance
  • High Abrasion Resistance
  • High Chemical Resistance
  • Impermeable
  • Difficult to Remove
  • Not Flexible
Parylene
Using vapor phase deposition, parylene coatings can be applied very thin and still provide excellent protection, making it the ideal choice for automotive, electronics, medical device, military and aerospace industries.
Advantages Disadvantages
  • Excellent Dielectric Strength
  • High Resistance to Solvent and Extreme Temperatures
  • Difficult to Remove
  • Requires Vapor Phase Deposition Equipment

Nano/Thin Film

Dissolved in fluorocarbon-based carrier solvent to create a very thin coating, although not in nanometer scale like the name suggests. They prevent shortages from very quick exposure to water which is ideal for communication technologies.
Advantages Disadvantages
  • Provide Minimal Amount of Hydrophobicity (Water Repellent)
  • Do Not Offer the Protection Level of Other Coating Methods