Printed Wiring Board Information

Conformal Coating

Conformal Coating Description

Conformal coating is a thin layer of dielectric material which applied to a printed wiring board.
Conformal coating provides environmental and mechanical protection to the circuits on the PWB.
Conformal coatings protect PCBs from moisture and contaminant, which prevent short circuits and corrosion of conductors & solder joints.
Conformal coatings also minimize dendritic growth [electro-migration] of metal between conductors.
There a number of types of Conformal Coatings;
........Acrylic Resin, Epoxy Resion, Silicon Resin, Polyurethane Resin, Paraxylylene, Ultra-Violet Curing.
Conformal Coating may be applied by either dipping, brushing or spraying the PCB with the material.

Conformal Coating Standards

Printed Wiring Board Specifications:
MIL-P-55110: Military Specification, General Specification For Printed-Wiring Boards
MIL-PRF-31032: Military Specification, General Specification For Printed Circuit Board/Printed Wiring Board
ANSI/J-STD-001: Requirements for Soldered Electrical and Electronic Assemblies
IPC-6012: Qualification and Performance Specification for Rigid Printed Boards
IPC-C-C-830: Qualification and Performance, Insulating Compounds for Printed Circuits Assemblies
MIL-I-46058C:Insulating Compound, Electrical (for Coating Printed Circuit Assemblies)
MIL-STD-275: Printed Wiring For Electronic Equipment
MIL-C-47175A(MI) - Compound, Polyurethane, for Conformal Coating of Electronic Circuitry
MIL-C-14550B - Copper Plating, (Electro-Deposited)
MIL-STD-2118 - Flexible and Rigid-Flex Printed Wiring for Electronic Equipment Design Requirements for
MIL-T-10727C - Tin Plating: Electro-Deposited or Hot-Dipped, for Ferrous and Non-ferrous metals
RoHS - Restriction of Hazardous Substances.

Conformal Coating Vendors

Companies Producing Conformal Coating:

Dow Corning Corporation
{RTV Elastomeric Coatings, RTV Elastoplastic Coatings, Solventless Heat Cure Coatings}

DYMAX Corporation
{Ultraviolet light curing Conformal Coatings}

{Silicone resin/Flexible acrylic coating, Spray on Conformal Coating. US MIL-1-46058C}

MG Chemicals
{Protective/Conformal Coatings}

Conformal Coating FAQ
{Thermospray Company Inc.}


Printed Circuit Board Data

Related Topics:

PWB Production Vendors
Integrated Circuit Packaging {MCM, MCP, COB, Hybrid Manufacturers}
Adhesives Manufacturers {Thermal, UV Cure, Conductive, Non-Conductive, Electrical Conductive, Elastimere}

Conductor Spacing per MIL-STD-275
Voltage Between Conductors Minimum Trace Spacing
DC or AC peak volts Surface Layers Internal Layers
0 - 100v 0.005" 0.004"
101 - 300v 0.015" 0.008"
301 - 500v 0.030" 0.010"

Graph of PWB External Etched Copper Current Capacity: current rating based on trace cross section in square mils, temperature rise and current in amperes.
Graph of PWB Internal Etched Copper Current Capacity: current rating based on trace cross section in square mils, temperature rise and current in amperes.
Graphic of Minimum Annular Ring, What is a Minimum Annular Ring.
Graph of PWB Ground Potential, moving away from a single point ground connection [example].
Description of Ground Loops
Definition of Printed Wiring Board Terms
The main PWB information page; Printed Wiring Board Information

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Modified 6/13/15
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