EPO-TEK OG198-55

Single-component thixotropic shadow-curable UV epoxy (more thixotropic version of OG198-54), 1,200–2,000 cPs, TI 6.0, Tg ≥120°C, die shear 27.7 Kg (UV+RT), ≥97% transmission @ 560–1,680 nm.

Product code:

OG198-55

Package size:

Shelf Life:

6 months refrigerated

RoHS Compliant

EPO-TEK OG198-55 is a single-component, high-viscosity, thixotropic shadow-curable UV epoxy — the more thixotropic version of EPO-TEK OG198-54. Manufactured by Epoxy Technology, Inc., its high thixotropic index (6.0) prevents flow on vertical surfaces after dispensing, while its shadow-cure capability ensures polymerization in UV-blocked areas. It achieves Tg ≥120°C and 27.7 Kg die shear after UV + RT cure.

Features & Benefits

Shadow cure + high thixotropy (TI 6.0) — stays in place on vertical surfaces and cures in UV shadows
Highest Tg in OG198 series: ≥120°C for demanding thermal environments
Die shear UV only: ≥20 Kg (7,112 psi) — immediate high fixture strength
Final die shear 27.7 Kg (9,850 psi) after UV + RT cure
Excellent transmission ≥97% @ 560–1,680 nm for visible to near-IR applications
Thermal post-cure beneficial for maximizing properties

Typical Applications

Vertical and overhead optical component bonding requiring shadow cure and non-flow behavior
Fiber optic assembly with complex geometry where UV shadows are unavoidable
Semiconductor die encapsulation requiring high-Tg UV-cure thixotropic paste
Photonic packaging requiring combined UV shadow cure and high temperature performance

Property	Value	Test Method / Condition
Color (before cure)	Translucent	Visual
Viscosity (23°C @ 100 rpm)	1,200–2,000 cPs	—
Thixotropic Index	6.0	—
No. of Components	Single	—
Glass Transition Temp	≥120°C	Dynamic Cure
CTE Below Tg	72 × 10⁻⁶ in/in°C	—
Shore D Hardness	85	—
Die Shear — UV only	≥20 Kg (7,112 psi)	—
Die Shear — UV + 23°C/24 hrs	27.7 Kg (9,850 psi)	—
Die Shear — UV + 80°C/1 hr	27.2 Kg (9,672 psi)	—
Spectral Transmission	≥97% @ 560–1,680 nm	—
Refractive Index (uncured)	1.5023 @ 589 nm	—
Refractive Index (cured)	1.5196 @ 589 nm	—
Particle Size	≤20 microns	—
Recommended Cure	Iron-doped Hg flood lamp >30 sec, 100 mW/cm² @ 240–365 nm	Thermal post-cure beneficial

Property

Value

Test Method / Condition

Color (before cure)

Translucent

Visual

Viscosity (23°C @ 100 rpm)

1,200–2,000 cPs

—

Thixotropic Index

6.0

—

No. of Components

Single

—

Glass Transition Temp

≥120°C

Dynamic Cure

CTE Below Tg

72 × 10⁻⁶ in/in°C

—

Shore D Hardness

—

Die Shear — UV only

≥20 Kg (7,112 psi)

—

Die Shear — UV + 23°C/24 hrs

27.7 Kg (9,850 psi)

—

Die Shear — UV + 80°C/1 hr

27.2 Kg (9,672 psi)

—

Spectral Transmission

≥97% @ 560–1,680 nm

—

Refractive Index (uncured)

1.5023 @ 589 nm

—

Refractive Index (cured)

1.5196 @ 589 nm

—

Particle Size

≤20 microns

—

Recommended Cure

Iron-doped Hg flood lamp >30 sec, 100 mW/cm² @ 240–365 nm

Thermal post-cure beneficial

Need this product for your project?

Request a Consultation

Fill in your requirements — our team will respond within 24 hours.