COOLTHERM EP-6037
Harmonization Code : 3910.00.00.90 | Silicones in Primary Forms; Others

Main features
- 1.2 W/(m K) Thermal Conductivity
- Two Hardener Options for Controlled CTE
- Room-Temperature Adhesive Cure
Product Description
CoolTherm® EP-6037 Epoxy System is a filled, thermally conductive epoxy resin platform used with CoolTherm® EP-6010 or EP-6252 Hardener. The system is primarily intended for semiconductor and power-electronics bonding, including thermally conductive joints in fabricated heat sinks and attachment of semiconductors or transistors to heat sinks. The black or green resin has a typical 500,000 cP viscosity at 25°C and 2.35 specific gravity. Both hardener systems cure in 24 hours at 25°C or 2 hours at 65°C. EP-6010 provides 1.2 W/m·K thermal conductivity and 106°C Tg, while EP-6252 provides 1.1 W/m·K conductivity, lower 31 ppm/°C CTE, and higher typical tensile and lap-shear strength.
Key features
- Thermally conductive epoxy system for semiconductor-to-heat-sink and fabricated heat-sink joints
- Two hardener options for different thermal, mechanical, and expansion requirements
- Room-temperature or 65°C accelerated cure with both supported hardeners
- Typical thermal conductivity of 1.2 W/m·K with EP-6010 or 1.1 W/m·K with EP-6252
- Typical dielectric strength above 15.7 kV/mm with both hardener systems
- Thin-bondline process using vacuum de-airing, mating-surface coating, squeeze-out, and clamping
- One-year resin shelf life at 25°C in the original unopened container
Applications
- Semiconductor and transistor attachment to heat sinks
- Thermally conductive joints in fabricated heat sinks
- General-purpose bonding of electronic components
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Physical Properties
Additional Information
CoolTherm® EP-6037 Epoxy System
A filled epoxy resin platform used with CoolTherm® EP-6010 or EP-6252 Hardener to form thermally conductive joints in semiconductor and power-electronics assemblies. The system supports bonding of semiconductors, transistors, fabricated heat sinks, and other electronic components using a de-aired, clamped thin bondline.
EP-6037 resin properties
EP-6037 is supplied as a highly filled black or green paste. Thorough stirring in the shipping container is required before withdrawing resin so the filler is uniformly dispersed.
| Property | Typical value | Selection context |
|---|---|---|
| Appearance | Black or green paste | Colour depends on the supplied resin version. |
| Viscosity at 25°C | 500,000 cP | Resin-only value; the catalogue reports 25,000 cP for the EP-6037/6252 mixed system. |
| Specific gravity | 2.35 | Typical as-supplied resin value. |
Select the hardener for the required joint properties
EP-6010 and EP-6252 are distinct hardener systems. Preserve their mix ratios, working lives, thermal properties, strength data, and moisture absorption separately.
| Selection field | EP-6010 Hardener | EP-6252 Hardener |
|---|---|---|
| Mix ratio by weight, resin:hardener | 100:3.4 | 100:7.1 |
| Working life at 25°C | 2 hours | 3 hours |
| Cure schedule | 24 hours at 25°C or 2 hours at 65°C | 24 hours at 25°C or 2 hours at 65°C |
| Thermal conductivity | 1.2 W/m·K | 1.1 W/m·K |
| Coefficient of thermal expansion | 52 ppm/°C | 31 ppm/°C |
| Glass transition temperature by TMA | 106°C | 70°C |
| Tensile strength at 25°C | 50 MPa | 60 MPa |
| Aluminium lap shear, 1-inch overlap | 1,450 psi | 2,175 psi |
Premix the resin, meter the selected hardener, de-air, coat both surfaces, and clamp
Thoroughly stir the EP-6037 resin in its shipping container, transfer the required amount to a clean vessel, and add the selected hardener by weight. Mix with an air-driven mixer while avoiding unnecessary air entrainment.
- Vacuum-evacuate the mixed epoxy for five minutes before application when following the documented bondline process.
- Apply the epoxy to both mating surfaces.
- Press the surfaces together and squeeze out excess material to obtain a thin bondline.
- Clamp the assembly to prevent movement during cure.
- Start cure timing after the material reaches the target temperature.
Stir EP-6037 thoroughly in the shipping container.
Use 100:3.4 with EP-6010 or 100:7.1 with EP-6252 by weight.
Evacuate for five minutes, then coat both mating surfaces.
Squeeze to a thin bondline, clamp, and cure at 25°C or 65°C.
Storage and handling
EP-6037 resin has a one-year shelf life when stored at 25°C in its original, unopened container. Before handling, review the current resin and hardener safety data sheets and labels. The supplied green-resin SDS identifies significant skin, eye, sensitisation, chronic-health, and aquatic hazards requiring trained industrial handling and appropriate workplace controls.
Hardener-specific thermal, mechanical, and electrical properties
These are typical cured-material and joint-test values. They must remain tied to the selected hardener, substrate, specimen, method, and cure condition.
| Property | EP-6010 Hardener | EP-6252 Hardener |
|---|---|---|
| Thermal conductivity, ISO 22007-2 | 1.2 W/m·K | 1.1 W/m·K |
| Coefficient of thermal expansion | 52 ppm/°C | 31 ppm/°C |
| Glass transition temperature by TMA | 106°C | 70°C |
| Hardness | 93 Shore D | 92 Shore D |
| Tensile strength at 25°C | 50 MPa (7,250 psi) | 60 MPa (8,700 psi) |
| Aluminium lap shear, 1-inch overlap | 1,450 psi | 2,175 psi |
| Elongation at yield | 1.9% | 4.1% |
| Moisture absorption, 10 days at 25°C | 0.076% | 0.17% |
| Volume resistivity at 25°C | >1 × 1015 ohm-cm | >1 × 1015 ohm-cm |
| Dielectric strength, ASTM D149 | >15.7 kV/mm (>400 V/mil) | >15.7 kV/mm (>400 V/mil) |
Thermally conductive structural bonding in electronics
The product is directly positioned for thermally conductive semiconductor and power-device joints. Broader Parker thermal-management and electric-vehicle pages provide market context but do not establish EP-6037-specific vehicle qualification or system-level outcomes.
Potting & Encapsulation Materials Catalogue — PC3002
The catalogue provides a controlled portfolio comparison and identifies the EP-6037/6252 system as a two-component epoxy for the semiconductor industry, including mixed viscosity, mix ratio, cure schedule, hardness, dielectric strength, and thermal conductivity.
Use for portfolio-level product comparison. Product selection and final property interpretation should remain grounded in the current EP-6037 technical datasheet and applicable hardener documentation.
Select the EP-6037 hardener and bondline process
Krayden can help review hardener selection, mix-ratio control, vacuum de-airing, substrate preparation, bondline, clamping, cure profile, CTE, Tg, adhesion, electrical insulation, and assembly-level thermal validation for CoolTherm® EP-6037.





















