2.4.2 Coating Replacement, Conformal Coating, Encapsulant

Outline

This method is used to replace conformal coatings and encapsulants on circuit boards.

Minimum Skill Level - Intermediate
Recommended for technicians with skills in basic soldering and component rework, but may be inexperienced in general repair/rework procedures.

Conformance Level - High
This procedure most closely duplicates the physical characteristics of the original, and most probably complies with all the functional, environmental and serviceability factors.

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


Procedure References
1.0	Foreword
2.1	Handling Electronic Assemblies
2.2	Cleaning
2.3.1	Coating Removal, Identification Of Coatings
2.4.1	Coating Replacement, Solder Mask
2.5	Baking and Preheating
2.7	Epoxy Mixing and Handling
IPC7721 2.4.2	Coating Replacement, Conformal Coatings/Encapsulants

Kits and Systems ▼

Tools and Materials ▼

Additional Items and Supplies ▼

Images and Figures

2.4.2 Coating Replacement, Conformal Coating, Encapsulant

Conformal Coating Required At Outlined Area

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

Figure 2: Coating complete.

Procedure

Clean the area.
Caution: Surfaces to be coated must be thoroughly cleaned before coating to ensure adequate adhesion, minimized corrosion, and optimized electrical properties.
If needed, apply High-Temperature Tape to outline the area where the coating will be applied.
If required, bake the circuit board before applying the replacement coating.
Mix the replacement coating.
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)
Cure the epoxy per Procedure 2.7 Epoxy Mixing and Handling.
Caution: Some components may be sensitive to high temperatures.

Evaluation

Visual examination for texture, color match, adhesion, and coverage.
Electrical tests to conductors around the repaired area as applicable.