Conformal coating analysis: what chemistry is on my circuit board?
Short answer
We can investigate the supported resin family, extractable additives, residual small molecules and elemental contribution of a cured conformal coating. For overseas receipt, cured films and circuit-board components without batteries can be considered after declaration review, while the original solvent-based liquid is not received as supplied. The English report describes the material actually sampled and its approximate composition, without establishing insulation performance, humidity resistance or film thickness.
Which question does your coated board need to answer?
Is the coating acrylic, silicone, polyurethane or epoxy?
Common conformal-coating families include acrylic, silicone, polyurethane and epoxy materials, with chemistry selected for different application and protection needs. Parylene-type coatings form another family with a different deposition process, so they should not be treated as an ordinary wet-coating formulation. A resin-family finding narrows the chemistry but does not identify the original commercial product or prove its protection rating.
Can a cured coating describe the supplied liquid?
Solvent-based, waterborne, UV-curable and solvent-free systems differ in what evaporates, reacts or remains during film formation. A cured specimen describes retained chemistry rather than the vanished liquid phase; our UV-curable material guide covers that reaction boundary for UV systems. For a two-part epoxy, the distinction between surviving components and original mixing ratios is covered in our cured epoxy guide.
Will board fragments or solder residue distort the coating result?
Removing a thin coating from a board can carry substrate fragments, solder residue or neighboring material into the specimen. A metal signal from that mixed specimen is not automatically an ingredient of the coating, and an accessible organic residue may belong to a neighboring assembly material. Identify the target area and any separation already performed using our layer-selection guide; flux-specific questions belong in our solder-flux guide.
How would we investigate a coating while keeping the board contribution visible?
1. We would photograph and divide the accepted specimen around the declared target, distinguishing a free-standing coating from a coating still attached to the board.
2. We would choose suitable extraction or separation for the coating and record any material carried across from the substrate, producing fractions with defined origins.
3. We would assess the supported resin family and examine suitable residual molecules by GC-MS and accessible additives by LC-MS/MS, retaining broader descriptions where cure limits identification.
4. We would measure relevant elements by ICP-MS and estimate supported component proportions on the coating or mixed-specimen basis actually analyzed.
5. We would compare corresponding regions of a reference and candidate where available, checking whether substrate carryover or different curing histories could explain apparent differences.
Why do residual molecules and elements help without revealing the entire cured network?
GC-MS can separate suitable residual solvent or plasticizer molecules released from a coating during preparation, then use their mass-spectral patterns to distinguish them within that extract. LC-MS/MS separates suitable nonvolatile coating extractables in liquid and tests selected ion-fragment relationships, supporting additive identities where fragments and reference evidence distinguish them from neighboring ingredients. Both measurements describe accessible material, and a molecule incorporated into a cured network may no longer appear in its original free form. ICP-MS measures the elemental content of suitably prepared material, so it can reveal an inorganic contribution without showing which board layer supplied it. Resin-family interpretation and the sample’s separation history must accompany these results; the three measurements are not a promise to read every bond in the intact coating.
What will the conformal-coating report say, and which protection questions remain open?
We would describe the supported resin family, identified or family-level extractables, estimated proportions and elemental findings in a conclusion card, component table and data appendix. The limitations note would distinguish coating evidence from possible board carryover, without turning composition into an insulation, humidity-resistance or thickness result.
Our reports are research-grade analytical reports from a laboratory that is not accredited. They cannot be used for product registration or legal proceedings.
Which circuit-board coating sample should you declare?
Declare cured film or a board component without batteries, with the SDS, target-area photographs and any removal history, for review. Water-based coating liquids are reviewed case by case after declaration; solvent-based and other non-water-based liquids are not received as supplied, so propose a cured coupon through our sample-form guide. Start at the industrial inquiry page, follow the shipping guide, and ship after the acceptance number.
FAQ
Can a removed coating reveal its original solvent blend?
No; a cured coating cannot preserve evaporated solvents, so its chemistry describes the retained film rather than the full supplied liquid.
Does detecting metal prove that it was added to the coating?
No; solder or substrate carryover can contribute metal, so the sampled region and removal history matter to that assignment.
Can composition prove moisture protection?
No; coating chemistry does not supply a humidity-resistance result or establish the insulation performance of the coated assembly.
Should I name the face of the board that was sampled?
Yes; identify the target face and neighboring materials so a mixed board specimen is not interpreted as pure coating.
Send a sample declaration and tell us what you want to learn from this sample.