EPO-TEK 921-FL
Harmonization Code : 3810.10.00 | Soldering, brazing or welding powders and pastes consisting of metal and other materials
Main features
- Thermally Conductive Electrical Insulation
- Six-Hour Mixed Pot Life
- Adhesive, Seal, and Potting Versatility
Product Description
EPO-TEK 921-FL Thermally Conductive Epoxy is a two-component, high-Tg epoxy that combines thermal conductivity with electrical insulation. The smooth-flowing paste mixes 100:2.2 by weight, has a six-hour pot life, and is the lower-viscosity version of EPO-TEK 921. A recommended cure of one hour at 150 deg C produces a typical bulk thermal conductivity of 1.1 W/(m K) and volume resistivity of at least 6 x 10^13 ohm cm. Supported uses include mounting heat sinks and substrates, sealing electronic packages, and thermal potting.
Key features
- Thermal conduction with electrical insulation: Typical cured values include 1.1 W/(m K) thermal conductivity and volume resistivity of at least 6 x 10^13 ohm cm.
- Controlled mixed-material window: The mixed system provides a six-hour pot life.
- Multiple thermal-management functions: The product supports heat-sink and substrate bonding, package sealing, and thermal potting.
Applications
- Mounting heat sinks and substrates
- Sealing electronic packages
- Thermal potting
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Physical Properties
Thermal Properties
Electrical Properties
Additional Information
As-supplied / before-processing properties
Typical as-supplied values for the two-component thermally conductive epoxy.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Mix ratio by weight | 100:2.2 | - | Part A:Part B |
| Specific gravity | Part A 2.39; Part B 1.02 | - | As supplied |
| Pot life | 6 | h | Mixed system |
| Shelf life - bulk | 6 | months | At room temperature |
| Shelf life - syringe | 6 | months | At -40 deg C |
| Color | Part A grey; Part B amber | - | Before cure |
| Consistency | Smooth flowing paste | - | Before cure |
| Viscosity | 12,000 to 20,000 | cP | At 23 deg C and 10 rpm |
After-processing / final-state properties
Typical cured values describe bulk material or stated test specimens, not complete assembly thermal performance.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Recommended cure | 1 | h | At 150 deg C |
| Alternative cure | 5 min at 150 deg C; 10 min at 120 deg C; 20 min at 100 deg C | - | Minimum alternative cures may not achieve all listed properties |
| Glass transition temperature | >= 90 | deg C | Dynamic cure: 20 to 200 deg C; ISO 25 min; ramp -10 to 200 deg C at 20 deg C/min |
| Shore D hardness | 87 | - | Typical cured value |
| Lap shear strength | 1,312 | psi | At 23 deg C |
| Die shear strength | >= 20 kg / 7,112 | psi | At 23 deg C |
| Thermal conductivity | 1.1 | W/(m K) | Typical bulk material value |
| Volume resistivity | >= 6 x 10^13 | ohm cm | At 23 deg C |
| Dielectric constant | 5.94 | - | At 1 kHz |
