Conformal Coating or Potting for Embodied Robot Controller PCBs: Zoned Protection Selection
For embodied robot controller PCBs, neither full‑board potting nor blanket thin coating is universally suitable. Open board areas, connector peripheries and high‑voltage sensitive zones shall be zoned first. The protection method is then selected against moisture, condensation, vibration, thermal cycling and serviceability requirements. ELAPLUS SIPC UV 3301 may be evaluated as a candidate conformal coating for PCB surfaces requiring UV/moisture dual‑cure. For stress‑sensitive local components such as pressure sensors, ELAPLUS SIGEL 1806, a low‑hardness, low‑stress two‑part silicone gel, is a candidate option. Final zoning boundaries must be validated with actual hardware, process and environmental qualification. Map Protection Requirements by Controller Location Controllers mounted near the robot torso, joints and end effectors face distinct operating conditions. Modules close to joints must withstand vibration and harness pulling; those adjacent to enclosures or air ducts are exposed to condensate, dust and residual cleaning agents. For sensors, extra stress induced by cure shrinkage or high modulus must be avoided. Define the PCBA placement, connector orientation, heat sinks, no‑coat zones and rework workflow before specifying protection materials, so the chosen adhesive does not become a bottleneck for manufacturing or repair. Work Division between Conformal Coating and Local Gel Encapsulation Location / Objective Preferred Approach Candidate Grade Core Validation Items Open PCB surfaces requiring thin‑film protection Selective conformal coating with defined no‑coat zones SIPC UV 3301, UV/moisture dual‑cure silicone conformal coating for PCBs Masking boundary, shadow‑zone cure, coating continuity, reworkability Locally mounted pressure / position sensors sensitive to external force Low‑stress local encapsulation or overmoulding SIGEL 1806 two‑component silicone gel Mix ratio, cure profile, signal baseline drift after cycling Standalone controller cavities or highly vibration‑prone edges Evaluate whether full potting is truly necessary Qualified separately by cavity geometry, thermal design and rework rules Fill integrity, exotherm, added mass, rework and functional testing Note: SIPC UV 3301…
