The Conformal Coating Removal Process

Removing unwanted conformal coating from a PCB can range from a straightforward task to a challenging undertaking. The ease or difficulty of the process is dictated by the type of coating that needs removal, its location on the board and the components present.

Identify the coating to be removed from the assembly first. Once determined, select the appropriate chemical stripper to dissolve it. Consulting a conformal coating professional for guidance in choosing the right chemical solution is recommended.

Once the chemical is chosen, the next step is to determine the necessary extent of coating removal. The quantity of coating to be eliminated significantly influences the selection of removal methods. If only a specific area requires rework, employing mild mechanical abrasion alongside the chemical stripper in the affected region typically suffices to dissolve the coating.

When the entire board requires stripping, the process becomes more complex. Complete immersion of the board in the stripping fluid along with agitation is crucial. Employing a stripping system that integrates multiple submersion tanks and the requisite agitation can facilitate the effective removal process.

A cautionary note is warranted. Prior to immersing in a stripping solution, ensure compatibility with the PCB. The stripping fluid may corrode plastic components and/or inscriptions on the boards, like serial number labels.

Fully stripping a circuit board can lead to another issue: the coating re-dissolves into the conformal coating stripper, spreading residue across the PCB, even in unintended areas like low profile connectors. Addressing these residues requires multiple stripping fluid tanks to rinse the PCB thoroughly, gradually eliminating the unwanted coating. After this process, the PCB should undergo cleaning to eliminate any remaining contamination.

General Disclaimer

Removing conformal coating typically involves very caustic chemicals that can potentially be damaging to the operators in the vicinity, are under strict control by local environmental organizations, and/or damaging to your product. It is highly recommended that you consult with a conformal coating professional before trying to remove conformal coating. Specialty Coating Systems assumes no responsibility for the actions taken as a result of this information.