Attend a 4 Day - Fiber Optics 1-2-3 Light Brigade Training Course held at Fiber Optic Center in New Bedford, MA. Upcoming class dates December 16-19, 2025. View More Details.

EPO-TEK® 301-2 Optically Transparent Epoxy, Heat Cure (2.5g)

ET301-2-2.5G

EPO-TEK® 301-2 General Bonding, Heat Cure Recommended, 2-Part Epoxy, 2.5 Gram Packet
The EPO-TEK® 301-2 Epoxy is a two-component, fiber optic epoxy featuring very low viscosity and excellent optical-mechanical properties. It is designed for optical applications such as lenses for optoelectronic display devices, bonding fiber optics (glass or plastic), and optical filters. EPO-TEK 301-2 can be used for bonding glass, quartz, metals, and most plastics. Recommended Cure: 80°C (176°F) for 3 hours.

Features:

  • Pot Life: 8 Hours
  • Can resist yellowing over 17 days of continuous UV light exposure
  • Resistant to impact and vibration
  • Low-stress adhesive
  • Passes NASA low outgassing standard ASTM E595 with proper cure

Applications:

  • Semiconductor:
    • Underfill for flip chips, glob-top encapsulation over wire bonds
    • Spin coating at wafer level, including wafer-level packaging
  • Fiber Optic Adhesive:
    • Fiber bundling and ferrule termination
    • Mounting optics inside fiber components
    • Bonding glass coverslips over V-grooves
    • Supports visible and IR spectral transmission
  • Easy to use for potting, casting, encapsulation, and adhesive applications
  • Excellent adhesion to glass, quartz, metals, wood, and most plastics
  • Can be used for impregnating wooden or porous objects for artifact restoration

Physical Properties:

  • Consistency: Pourable liquid
  • Viscosity (23°C): 225 - 425 cPs
  • Glass Transition Temperature, Tg: ≥ 80°C (degree Celsius); ≥ 185°F (degree Fahrenheit)
  • Shore D Hardness: 80
  • Coefficient of Thermal Expansion (CTE):
    • Below Tg: 61 x 10-6 in/in°C
    • Above Tg: 180 x 10-6 in/in°C
  • Suggested Operating Temperature: < 300 °C (Intermittent); < 572°F 

Optical Properties:

  • Spectral Transmission:
    • ≥ 94% @ 320 nm
    • ≥ 99% @ 400-1,200 nm
    • ≥ 98% @ 1,200-1,600 nm
  • Refractive Index: 1.5318 @ 589 nm
See Datasheet for additional properties and application notes

Fiber Optic Center

4.9 70 Google reviews

Represents overall Google Reviews of Fiber Optic Center, Inc.