Circuit Board Repair Guide > Basic Circuit Board Repair Procedures > 2.4.2 Replace Conformal Coatings and Encapsulants on Printed Circuit Boards

Replace Conformal Coatings and Encapsulants on Printed Circuit Boards

Repair Circuit Boards | Repair SMT Pads | Repair BGA Pads | Repair Lands | Repair Edge Contacts
Repair a Conductor | Plated Hole Repair | Base Board Repair | Replace Solder Mask or Coatings

This coating replacement procedure is used to replace conformal coatings and encapsulants on printed circuit boards.

IPC Acceptability References
IPC-A-600 2.0 Externally Observable Characteristics
IPC-A-610 10.0 Laminate Conditions

Related Procedure References
CTC 1.0 Foreword - Circuit Board Repair Guide
CTC 2.1 Handling Electronic Assemblies
CTC 2.2.1 How to Clean a Circuit Board
CTC 2.2.2 Cleaning Circuit Boards, Aqueous Batch Process
CTC 2.3.1 Coating Removal, Identification of Coatings
CTC 2.4.1 Replace Solder Mask or Coatings on Printed Circuit Boards
CTC 2.5 Baking and Preheating of Printed Circuit Boards
CTC 2.7 Epoxy Mixing and Handling
IPC 7721 2.4.2 Coating Replacement, Conformal Coatings / Encapsulants

Tools and Materials
Color Agents
Circuit Epoxy 
Foam Swabs
Heat Lamp
Replacement Coating
Conformal coating required at outlined area
Conformal Coating Required
At Outlined Area

2.4.2 Coating Replacement, Conformal Coating, Encapsulant

Printed Board Type: R/F/W/C  |  Skill Level: Intermediate  |  Conformance Level: High  |  Rev.: D

Apply replacement coating with foam swab

Figure 1: For large surfaces,
apply the replacement coating
with a foam swab to create a

Coating replacement is complete

Figure 2: Coating complete.
1. Clean the area.

Surfaces to be coated must be thoroughly cleaned prior to coating to ensure adequate adhesion, minimized corrosion, and optimized electrical properties.
2. If needed, apply Kapton tape to outline the area where the soldermask will be applied.
3. If required, bake the circuit board prior to the application of the replacement coating.
4. Mix the replacement coating.
5. Apply the replacement coating to the board surface as required. A brush or foam swab may be used to apply and spread the replacement coating. (See Figure 1).
6. Cure the epoxy per Procedure 2.7 Epoxy Mixing and Handling.

Some components may be sensitive to high temperature.
1. Visual examination for texture, color match, adhesion and coverage.
2. Electrical tests to conductors around the repaired area as applicable.

Links to Related Products

Circuit board epoxy for ciruit repair   Circuit Bond Kit 115-1322: Liquid circuit board epoxy
Circuit Bond Kit contains 10 packages of clear, low viscosity, superior strength epoxy ideal for circuit board use. The epoxy is precisely measured out into two-compartment plastic packages. This adhesive is easy to use and there's no measuring.

Color Agents for Circuit Boards
Matching epoxy to the color of the circuit board being repaired is easy when you use a color agent. Color agents may also be applied directly to the circuit board surface for color matching.

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