Selecting an adhesive with a low coefficient of thermal expansion (CTE) is one of the approaches to improve the bond strength and stability between dissimilar substrates. Low CTE adhesives mitigate the mismatch in thermal expansion between the substrates being bonded, as well as between the substrates and the adhesive.
One and two component advanced epoxy systems have been developed for joining dissimilar substrates exposed to thermal/mechanically induced stresses. These dimensionally stable, low shrinkage compounds which are formulated with select fillers offer extra low coefficients of thermal expansion. Products provide the integrity of bonded joints even from high/low temperature exposure. Grades consist of electrically insulative and thermally conductive/electrically isolating systems. They are available for use in a variety of viscosities. NASA low outgassing approved systems meet ASTM E595 requirements for critical aerospace, optical, electronic and specialty OEM needs. Select products have been employed as thermal interface materials to optimize heat transfer and improve device reliability.
| Product | CTE ppm/°C @ 23°C | Tg | Service Temperature Range |
|---|---|---|---|
| EP42HT-2LTE | 9-12 | 60-70°C | 4K to +300°F (4K to +149°C) |
| EP30LTE-2 | 10-13 | 85-95°C | -100°F to +250°F (-73°C to +121°C) |
| EP42HT-3AO | 10-20 | 140-145°C | -100°F to +400°F (-73°C to +204°C) |
| EP13LTE | 15-20 | 160°C | -60°F to +500°F (-51°C to +260°C) |
| Common Materials: Typical CTE Range for Comparison | |
|---|---|
| Material | CTE ppm/°C @ 23°C |
| Ceramics | 0 - 10 |
| Metals | 10 - 30 |
| Plastics | 40 - 120 |
| Rubbers | 100 - 300 or higher |
Most Popular Low Coefficient of Thermal Expansion Epoxies
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EP21TCHT-1 Two part, room temperature curable epoxy system with high thermal conductivity. Serviceable from cryogenic temperatures up to +400°F. Electrically isolating. Meets NASA low outgassing specifications. Halogen free. Paste consistency. Formulated to cure at ambient temperatures. Withstands 1,000 hours 85°C/85% RH. |
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EP30LTE-LO Two component epoxy system. Extra low thermal expansion coefficient and unmatched dimensional stability. Bonding, sealing, casting compound. Passes NASA low outgassing specifications. Room temperature curing. Low shrinkage. Serviceable from 4k to +250°F. Successfully tested for 1,000 hours 85°C/85% RH. |
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EP13SPND-2 Non-drip single component adhesive. Will not flow when cured. Serviceable up to +500°F. Electrically insulative. Withstands 1000 hours 85°C/85%RH. Excellent bond strength properties. |
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EP42HT-2LTE Ultra low coefficient of thermal expansion. Two component, room temperature curing epoxy. Reliable electrical insulator. Unsurpassed dimensional stability. Low linear and volumetric shrinkage upon cure. Serviceable from -60°F to +300°F. Withstands 1,000 hours 85°C/85% RH. |
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EP30LTE-2 Thermally conductive, electrically insulative epoxy. Has low thermal expansion coefficient. Superior dimensional stability. Good flow properties. Exceptionally low shrinkage upon cure. Service operating temperature range from -100°F to +250°F. Adheres well to similar and dissimilar substrates. |
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EP5LTE-100 One component flowable epoxy for bonding and sealing applications. Unlimited working life. Low coefficient of thermal expansion. Non conductive. |
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Supreme 10ANHT-LO NASA low outgassing approved one component thermally conductive epoxy adhesive. Cryogenically serviceable. Smooth paste consistency. Low coefficient of thermal expansion. Effective shear and peel strength. Stellar electrical insulation properties. Serviceable from 4K to +400°F. |
