For UL, the conformal coat is considered an Insulation System, and shall be a r/c. There are both mechanical and electrical Type Tests for this application as insulation. Also, the application process must be controlled, documented, and audited.
If you can convince the examining engineer that the insulation is not subject to the requirements for sheet insulator, that the application is homogenous and free of any pockets, can always verify a minimum thickness, and that production tests will mitigate anomalies, well sure, why not ? Side note: distance through insulation is NOT defined in 61010-1, cl 6.7: "There are not clearance or creepage distance requirements for the interior of of void-free moulded parts, including inner layers of multi-layer printed circuit boards." the important clause is 6.7.3.1c - this is the test for mitigation. luck, Brian -----Original Message----- From: Bill Flanigan [ mailto:[email protected]] Sent: Friday, November 21, 2003 5:23 AM To: [email protected] Subject: Insulation enhancement? Premise: EN61010-1:2001 On a PCB, where adjacent surface traces do not provide double insulation between haz-live and accessible circuits, is the spot application of conformal coating to the traces acceptable as supplementary insulation?
