CoolTherm® SC-324 Thermally Conductive Silicone
Harmonization Code : 3910.00.00.90 | Silicones in Primary Forms; Others
Main features
- 4.0 W/m·K thermal conductivity
- Durable UL 94 V-0 flame rated, addition-cure PDMS
- Low-stress low viscosity potting
Product Description
CoolTherm® SC-324 is a two-component, addition-cure (PDMS) thermally conductive silicone encapsulant for electrical and electronic potting applications that require heat transfer plus silicone compliance. It provides 4.0 W/m·K typical thermal conductivity while maintaining low cure stress, electrical insulation, and environmental resistance. This makes it well-suited for assemblies exposed to vibration, thermal cycling, thermal expansion mismatch, and mechanical shock.
Product Key Features
- Thermally Conductive - 4.0 W/m·K typical thermal conductivity for improved heat flow through the encapsulant.
- Low Stress - low shrinkage and low cure stress to help reduce stress on sensitive components during cure.
- Durable Addition-Cure Silicone - PDMS chemistry designed not to depolymerize when heated in confined spaces.
- Low Viscosity - supports wet-out and fill of complex geometries compared to many highly thermally conductive potting materials.
- Environmentally Resistant - thermal shock resistance and flame retardancy for harsh operating conditions.
- UL Rated - UL 94 V-0 certified flame rating.
Applications
After cure, SC-324 forms a compliant silicone elastomer, supporting deep-section potting and assemblies where thermal expansion mismatch and vibration can drive mechanical stress. For dielectric-critical designs, void control is often important to preserve electrical performance.
- Power Module Potting: Potting of inverters, converters, and power supplies to provide insulation and environmental protection while supporting heat transfer.
- Electric Motors: Encapsulation of windings or stator regions to improve the thermal path from heat-generating components to the housing or cooling structure.
PL-SC324
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Shipping in 8 weeksPackaging
TDS, SDS & Technical Documents
- Technical-Datasheet-CoolTherm-SC-324_DS4278
- Safety-Data-Sheet-COOLTHERM-SC-324-RESIN
- Safety-Data-Sheet-COOLTHERM-SC-324-HARDENER
Technical Specifications
General Properties
Physical Properties
Thermal Properties
Mechanical Properties
Chemical Properties
Electrical Properties
Additional Information
CoolTherm® SC-324
CoolTherm® SC-324 is a two-component, addition-cure (PDMS) silicone encapsulant for electrical and electronic potting where thermal transfer and silicone compliance are both required. It delivers 4.0 W/m·K typical thermal conductivity while retaining silicone advantages such as low cure stress, electrical insulation, and environmental resistance for assemblies exposed to vibration, thermal cycling, and mechanical shock.
Note: Property values shown are typical and not intended for specification. Verify suitability under your geometry, dispense method, and cure profile.
Key Features
- Low stress to help reduce cure-induced stress on sensitive components.
- Durable addition-cure PDMS designed not to depolymerize under heat in confined spaces.
- Low viscosity relative to many highly thermally conductive potting materials to support wet-out of complex geometries.
- Environmental resistance with thermal shock resistance and flame retardancy.
- UL 94 V-0 flame rating (per technical data sheet).
Processing Summary
Uncured System Properties (25°C)
| Property | SC-324 Resin | SC-324 Hardener | Mixed |
|---|---|---|---|
| Appearance | Pink liquid | White liquid | Light pink liquid |
| Viscosity (cP) at 25°C | 37,000 | 43,000 | 30,000 |
| Specific gravity | 3.25 | 3.25 | 3.25 |
| Working life (minutes) at 25°C | - | - | 30 |
Cured Properties (typ.)
Cure basis: 60 minutes at 125°C (time at temperature after the part reaches target temperature).
| Property | Typical value | Test method |
|---|---|---|
| Thermal conductivity (W/m·K) | 4.0 | ISO 22007-2 (Hot Disk transient) |
| Coefficient of linear thermal expansion (ppm/°C) | 105 | Per technical data sheet |
| Hardness (Shore A) | 50 | ASTM D2240 |
| Tensile strength (MPa) | 0.82 | ASTM D412 |
| Elongation at break (%) | 10 | ASTM D412 |
| Moisture absorption (%) | <0.1 | ASTM D570 |
| Volume resistivity (ohm-cm) at 25°C | >2 x 1013 | ASTM D257 |
| Dielectric strength (kV/mm) | 7.4 | ASTM D149 |
| Dielectric constant at 1 MHz | 4.5 | ASTM D150 |
| Dissipation factor at 1 MHz | <0.01 | ASTM D150 |
| Extractable ionic contaminants (ppm) | <10 each (chloride, sodium, potassium, ammonium, bromide, sulfate) | Per technical data sheet |
Where SC-324 Fits
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- Thermal benchmark: 4.0 W/m·K (typ.).
- Flame rating: UL 94 V-0 (per technical data sheet).
- Quality lever: Minimize voids for dielectric-critical designs.
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- Flow benchmark: 30,000 cP mixed viscosity at 25°C (typ.).
- Dielectric benchmark: 7.4 kV/mm dielectric strength (typ.).
- Compatibility: Avoid cure inhibitors (amines, sulfur, tin salts); patch test if uncertain.
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- Electrical benchmark: >2 x 1013 ohm-cm volume resistivity at 25°C (typ.).
- Moisture benchmark: <0.1% moisture absorption (typ.).
- Quality lever: Avoid trapped air to reduce thermal resistance.
Tips and Troubleshooting
| Issue | Recommended Action |
|---|---|
| Air bubbles and voids |
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| Incomplete cure |
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| Thermal or electrical performance below target |
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