Key Features

• Environmental Protection
  Protects circuit boards from the effects of contaminants in the air. Circuit board components are isolated from contaminants like hydrogen sulfide (H₂S), chlorine (Cl), or salts.
• Mechanical Protection
  Works to shield and protect the circuit board from dust, insects, dropped screws, drill shavings, and abrasion.
• Dendrite Growth Resistance
  Resists dendrite growths between conductors. SEL coatings conform to the peaks and recesses of the board, providing complete coverage of critical components.
• Moisture Protection
  Provides a moisture-resistant barrier, preventing unwanted conduction paths and board damage.
• Precision Robotic Application
  Precisely applied to surfaces intended for coating and not to unintended areas. Computer-controlled, three-axes application gives uniform coating to exact specifications, resulting in superior reliability.

Products

SEL offers conformal coating on the following products:

SEL-300G SEL-311A, B, and C SEL-311L SEL-351-5, -6, -7 SEL-351A SEL-351S SEL-352 SEL-387-0, -5, -6 SEL-387A SEL-387E SEL-421 SEL-451

SEL-487B SEL-501 SEL-551 SEL-551C SEL-587 SEL-587Z SEL-701 SEL-710 SEL-749M SEL-751A SEL-2032/2030 SEL-2411

Check with your SEL customer service representative on the availability of conformal coating on other products. Operating temperature for some UL and CSA conformal-coated boards is –40° to +75°C (–40° to +167°F).

Conformal coating is specially formulated to protect PCBs and related equipment from the environment. This improves and extends the working life of the PCB and ensures security and reliability. The coating conforms to the shape of the board and its components, creating a protective layer that is both lightweight and flexible.

This durable protective coating protects circuitry from hazards such as chemicals (e.g., fuels, coolants, etc.), vibration, moisture, salt spray, humidity and high temperature, fungus, corrosion, and thermal shock.

SEL products with conformal coating have been tested and approved by independent testing laboratories to the following specifications for mixed flowing gas, hygroscopic dust, and damp heat:

• Telcordia Technologies GR-63-CORE, Issue 2, April 2002, Network Equipment-Building System (NEBS) Requirements: physical protection (modified—test duration extended)
• EIA 364-65A Class IIIA (modified—test duration extended)
• ANSI NCSL Z540-1
• ISO 17025: 2005
• IEC 60068-2-30—1980, 1985, Basic Environmental Testing Procedures, Part 2: Tests—Test Db and guidance: damp heat, cyclic (12 + 12-hour cycle), severity level 25° to 55°C, 6 cycles, relative humidity 95 percent.

Mixed flowing gas includes contaminants Cl₂, H₂S, NO₂, and SO₂. Hygroscopic dust includes water-soluble salts, sulfate, nitrites, volatile organic compounds, SO₂, H₂S, ammonia, NO, NO₂, HNO₂, ozone, and gaseous chlorine.

SEL meets Mil-1-46058C Type UR conformal coating requirements. Material used for conformal coating is approved to the following specifications:

• IPC-CC-830, Qualification and Performance of Electrical Insulating Compounds for Printed Board Assemblies.
• UL 746E, Polymeric Materials—Industrial Laminates, Filament Wound Tubing, Vulcanized Fiber, and Materials Used in Printed Wiring Boards.
• IEC 60664-3, Insulation Coordination for Equipment Within Low-Voltage Systems, Part 3: Use of Coatings to Achieve Insulation Coordination of Printed Board Assemblies.