Circuit Board Repair and Rework Guide > 2.0 Basic Procedures > 2.3.3 Coating Removal, Peeling Method

2.3.3 Coating Removal, Peeling Method

Printed Board Type: R/F/W/C
Skill Level: Advanced
Conformance Level: High
Revision: E
Revision Date: Jul 7, 2000

Outline
This peeling removal method for coating can be used only under special circumstances. Normally this method is used to remove RTV silicone or other thick rubbery-like coating materials.

Coating Removal Required
At Outlined Area

The coating material is removed using a dull knife or otherwise dull blade to slit the coating material and to peel it off the printed board or printed board assembly.

To determine the appropriate coating removal procedure the coating must first be identified. Refer to procedure number 2.3.1.

Note
This method is limited to coatings that are rubbery in nature to allow the coating material to be slit into small sections and peeled off the printed board assembly.

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

Procedure References
CTC	1.0	Foreword
CTC	2.1	Handling Electronic Assemblies
CTC	2.2	Cleaning
CTC	2.3.1	Coating Removal, Identification of Coatings
CTC	2.4.1	Coating Replacement, Solder Mask
CTC	2.4.2	Coating Replacement, Conformal Coatings/Encapsulants
IPC 7721	2.3.3	Coating Removal, Peeling Method see procedure below

Tools and Materials
Heated Blade or Thermal Parting Tool
Knife
Wood Sticks

Procedure 2.3.3 Coating Removal, Peeling Method

Figure 1: Slit and peel off coating
using a knife or heated blade.

1.	Slit and peel off the coating material with a dull knife or heated dull blade. (See Figure 1).

2.	Repeat as needed until the required material is removed.

Figure 2: Removal complete.

Evaluation

1.	Visual examination or UV light may be used to verify complete removal of coating