EPO-TEK® H74 Thermally Conductive Epoxy, Thixotropic, Heat Cure (3oz)

EPO-TEK® H74 is a two-component, thermally conductive, high-temperature epoxy designed for hybrid circuit assembly, including die attach, substrate attach, lid-seal, heat dissipation, and hermetic sealing in general. Available in a 3 oz kit.

Recommended Cure: 150°C for 1 Hour

Features for H74:

• High temperature, high viscosity epoxy
• Passes NASA low outgassing standard ASTM E595 with proper cure
• Thixotropic paste allows for good handling characteristics
• Outstanding high temperature properties and excellent solvent, chemical and moisture resistance.
• Capable of providing a near-hermetic seal.
• Pot Life: 2 Hours

Physical Properties:

• Color (before cure):
  • Part A: Grey
  • Part B: Amber
• Consistency: Thixotropic Paste
• Viscosity (23°C) @ 5 rpm: 45,000 - 65,000 cPs
• Thixotropic Index: 2.1
• Glass Transition Temperature, Tg: ≥ 100°C
• Coefficient of Thermal Expansion (CTE):
  • Below Tg: 21 × 10⁻⁶ in/in/°C
  • Above Tg: 95 × 10⁻⁶ in/in/°C
• Lap Shear @ 23°C: 1,656 psi
• Die Shear @ 23°C: ≥ 15 Kg (5,334 psi)
• Degradation Temp: 425°C
• Weight Loss:
  • @ 200°C: 0.29%
  • @ 250°C: 0.50%
  • @ 300°C: 0.80%
• Suggested Operating Temperature: < 350°C (Intermittent) (< 662°F)
• Storage Modulus: 860,430 psi
• Particle Size: ≤ 50 microns

Electrical and Thermal Properties:

• Thermal Conductivity: 1.3 W/mK
• Volume Resistivity @ 23°C: ≥ 4 x 10¹² Ohm-cm
• Dielectric Constant (1KHz): 4.95
• Dissipation Factor (1KHz): 0.007