COOLTHERM EP-343
Harmonization Code : 3910.00.00.90 | Silicones in Primary Forms; Others
Main features
- 1.1 W/(m K) Thermal Interface
- 1 to 6 mil Spray Coats
- 59 kV/mm Dielectric Strength
Product Description
CoolTherm® EP-343 Thermally Conductive Epoxy Conformal Coating is a two-component, dielectric epoxy coating recommended for printed circuit boards, semiconductors, and heat sink assemblies. The black, low-viscosity mixed material can be applied with conventional spray equipment at 1–6 mils per application. After the documented cure schedule, it provides a typical thermal conductivity of 1.1 W/m·K, high electrical insulation, and an operating temperature range of -65 to 130 °C. The cured coating also provides resistance to water and a variety of chemicals, along with edge coverage and hiding power in thin applications.
Key features
- Thermally conductive dielectric coating: Provides a typical cured thermal conductivity of 1.1 W/m·K using the Hot Disc Transient Method, ISO 22007-2.
- Low-viscosity spray application: The mixed material has a typical viscosity of 55 cP at 25 °C and can be sprayed at 1–6 mils per application.
- Electrical and temperature performance: Provides a typical dielectric strength of 59 kV/mm at 0.003-inch thickness and supports operating temperatures from -65 to 130 °C.
Applications / Suitable for
- Printed circuit board coating
- Semiconductor coating
- Heat sink assembly coating
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TDS, SDS & Technical Documents
Technical Specifications
General Properties
Physical Properties
Thermal Properties
Mechanical Properties
Chemical Properties
Electrical Properties
Additional Information
As-supplied / before-processing properties
Typical properties of the separate components and mixed coating before cure. Values are not intended for specification purposes.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Appearance | Black liquid / amber liquid / black liquid | — | EP-343 resin / EP-343 hardener / mixed material |
| Mix ratio | 100:3.9 | By weight | EP-343 resin : EP-343 hardener; no dilution required |
| Viscosity | 65 / 55 / 55 | cP | Resin / hardener / mixed material at 25 °C; test method not stated |
| Specific gravity | 1.41 / 0.99 / 1.35 | — | Resin / hardener / mixed material; test conditions not stated |
| Working life | 24 | hours | Mixed material at 25 °C |
| Recommended applied thickness | 1–6 | mil | Spray-applied in one application; greater thicknesses require partial oven curing between coats |
| Shelf life | 1 / 2 | years | Resin / hardener when stored at 25 °C in original, unopened containers |
After-processing / final-state properties
Typical cured properties after an initial cure of 2 hours at 65 °C followed by a post-cure of 4 hours at 135 °C. Values are not intended for specification purposes.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Thermal conductivity | 1.1 | W/m·K | Hot Disc Transient Method, ISO 22007-2 |
| Coefficient of linear thermal expansion | 24 | ppm/°C | ASTM C864 |
| Glass transition temperature | 106 | °C | Test method not stated |
| Hardness | 90 | Shore D | Test method not stated |
| Tensile strength | 57.22 (8,300) | MPa (psi) | Test method not stated |
| Moisture absorption | 0.2 | % | 10 days at 25 °C; exposure medium not stated |
| Volume resistivity | 1 × 1016 | ohm-cm | ASTM D257 at 25 °C |
| Dielectric strength | 59 (1,500) | kV/mm (V/mil) | 0.003-inch specimen thickness; ASTM D149 |
