EPO-TEK OE121 is a two-component, optically clear, low-stress capillary-grade semiconductor underfill designed for opto-device flip chip packaging. Manufactured by Epoxy Technology, Inc., it flows by capillary action under flip chip assemblies and cures at low temperatures (23–80°C) while maintaining >94% optical transmission at 380–1,600 nm. It can also be used for general potting and encapsulation.
Features & Benefits
- Optically clear after cure: >94% transmission @ 380–1,600 nm for optical flip chip packages
- Low-temperature cure (23°C to 80°C) — safe for heat-sensitive opto-electronic devices
- Low viscosity (300–500 cPs) enables capillary flow under flip chip bumps without voids
- Low-stress formulation minimizes thermomechanical stress on delicate optical chip structures
- High die shear ≥15 Kg (5,334 psi) for reliable underfill mechanical performance
- Long 5-hour pot life for production scheduling in manual or semi-automated assembly
Typical Applications
- Capillary underfill of opto-device flip chip packages requiring optical transparency
- Underfill of LED and photodetector flip chips in optical modules
- General potting and encapsulation in electronics, medical, and optical industries
- Optical encapsulation of flip chips where bond line must remain transparent