MIL-I-46058C Military Specification: Insulation Compound, Electrical (For Coating of Printed Circuit Assembly)

The MIL-I-46058C standard, a United States military defense standard, covers coatings suitable for application to printed circuit assemblies by dipping, brushing, spraying, or vacuum deposition.

This military insulation compound standard is a common standard used in industry for shape-retaining coating materials. While this standard is inactive for new designs, it is still a frequently requested standard by military contractors. The main advantage of the MIL-I-46058C standard is that it requires independent testing by a military-approved laboratory.

This standard covers the following types of coatings:

• AR type: Acrylic resin
• ER type: Epoxy resin
• SR type: Silicone resin
• UR type: Polyurethane resin
• XY type: Paraxylene

The requirements described in this standard are as follows:

• Qualification: Coating materials supplied under this standard must be products included in the valid qualified products list.
• Materials: The materials must not contain harmful substances and must be formulated with synthetic resins, elastomers, plasticizers, catalysts and other ingredients that meet the requirements of this standard.
• Composite coating system: A composite coating system within the scope of this standard should be considered as a single material. Primer and coating are prepared in accordance with the recommendations of the supplier company. Precoating surface treatments should be considered as part of the coating system.
• Compatibility: The coating materials will be suitable for application and use in printed circuit assemblies and must be compatible with the materials used therein. Coatings must not degrade materials used in printed circuit assemblies or components connected to them.
• Curing time and temperature: When coating materials are tested, the material should be cured to full hardness at the time and temperature recommended by the supplier. Drying time should not exceed 4 hours for AR type, 8 hours for ER type, 24 hours for SR and UR types unless otherwise stated. The curing temperature should not exceed 125 degrees unless otherwise stated. Type XY coating should be cured by vacuum precipitation method.

Among the numerous tests, measurements, analyses, and evaluations our organization provides for businesses in various sectors, we also offer insulation compound testing services for the coating of electrical printed circuit boards within the scope of the MIL-I-46058C standard, thanks to our trained and expert staff and advanced technological equipment.