LETBOND® UV Curing Adhesive Series
Description
The LETBOND® UV Series encompasses advanced acrylic and cationic epoxy formulations designed for high-precision industrial assembly. This comprehensive portfolio offers solutions ranging from plastic structural bonding and waterproof glass lamination to connector/solder joint reinforcement, lens module active alignment, and optical gap filling.
With features including ultra-low shrinkage, color-change indicators, fluorescent inspection, and dual-cure mechanisms (UV + Moisture/Heat), this single-component, solvent-free series ensures high-speed production efficiency and long-term reliability across diverse substrates.
Features
- Superior Multi-Substrate Adhesion: Engineered for high-strength bonding of plastics (ABS, HIPS, PS, PC, PVC, PMMA, LCP, etc.), glass, metals, ITO, and specialized P+R (Plastic + Rubber) applications like plated PC to silicone.
- High-Efficiency Curing: Most grades are optimized for 365nm UV; selected versions support 400–420nm visible light. Multiple curing options include UV + Moisture, UV + Thermal, and deep-section curing.
- Optical-Grade Low Shrinkage: Cationic epoxy 5857 features a volume shrinkage of only 0.95% with a Tg of 115°C. 5858 (UV + 80°C post-bake) provides extreme heat resistance and low moisture permeability.
- Hydrolytic Stability & Anti-Yellowing: 5802/5802L are specifically formulated for glass lamination, ensuring no delamination even under long-term water immersion.
- Process Visualization: Features include Color-Change (Red to Clear upon cure: 58037/58034), Fluorescent Inspection (EXA603-21-4F1), and Visible Light Curing (EXA603-21-4M).
- Reworkable & Peelable: Specialized formulas for TP frames and airtight sealing that can be cleanly peeled off without residue for easy rework.
Applications
- Structural Plastic Bonding: * Grades: 5848, EX-448, 5844, 5841, EX4481, 5254.
- Glass Lamination & Optical Clarity:
- 5802 / 5802L: Long-term water resistance and anti-yellowing for glass surfaces.
- 5840: High-capillary penetration for precision lens lamination.
- Connector & FPC Reinforcement/Coating:
- EX4481-15-F / 5867: High-strength black reinforcement.
- 58051: Dual UV + Moisture cure for shadowed areas.
- EXA603-21 Series: Includes visible light and fluorescent inspection options.
- Camera Module & Active Alignment (AA):
- 5254, 5867, HV054-4: Precision positioning and focus fixing.
- High-Reliability Optical Components:
- 5857: UV pre-cure + Thermal cure for ultra-low stress.
- 5858: High stability (UV + 1hr @ 80°C post-bake).
- Process Verification & Inspection:
- 58037 / 58034: Visual confirmation via color change.
- EXA603-21-4F1: Fluorescent detection under UV light.
- EXA603-21-4M: Rapid curing via visible light.
- Peelable Masking & Airtight Sealing:
- 58596, 85001: Temporary protection and bezel sealing for easy rework.
- P+R (Plastic + Rubber) Assembly:
- 5874: Specialized bonding for PC/PMMA or plated PC to silicone rubber.
Selection Specifications
A. Plastic-to-Plastic / General Structural Bonding
| Model | Color |
Viscosity (cps) |
UV Energy |
Hardness (Shore) |
Temp. Range (°C) |
|---|---|---|---|---|---|
|
5254 |
Clear Paste |
S14 10rpm: 80k–120k 1rpm: 200k–410k |
1,000–2,000 mJ/cm2 |
D 66 ± 2 |
-40~100 |
|
5841 |
Clear Liquid |
S21 10rpm: 1,000–1,500 |
1,500–3,000 mJ/cm2 |
D 30 |
-40~100 |
|
5844 |
Clear Liquid |
S21 100rpm: 125–225 |
1,500~2,000 mJ/cm2 |
D 40 |
-40~100 |
|
5848 |
Translucent Tan |
S14 50rpm: 6,500–9,500 |
1,500~2,000 mJ/cm2 |
D 70 ± 2 |
-40~80 |
|
EX-448 |
Clear Liquid |
S14 50rpm: 6,500–9,500 |
1,500~2,000 mJ/cm2 |
D 70 ± 2 |
-40~80 |
|
EX4481 |
Deep Blue Paste |
S14 50rpm: 12,000–18,000 |
1,500–2,000 mJ/cm2 |
D 77 ± 3 |
-40~80 |
B. Glass Lamination / Waterproof Grade (Water & Yellowing Resistant)
| Model | Color |
Viscosity (cps) |
UV Energy |
Hardness (Shore) |
Temp. Range (°C) |
|---|---|---|---|---|---|
|
5802 |
Clear Paste |
S14 20rpm: 16,000–26,000 |
1,500–3,000 mJ/cm2 |
D 71 |
-40~100 |
|
5802L |
Clear Liquid |
S14 100rpm: 6,400–9,600 |
1,500–3,000 mJ/cm2 |
D 67 |
-40~100 |
|
5840 |
Clear Liquid |
S21 20rpm: 450–650 (Low Visc.) |
1,500–3,000 mJ/cm2 |
D 38 |
-40~100 |
C. Electronic Connectors / FPC Reinforcement & Coating
| Model | Color |
Viscosity (cps) |
UV Energy |
Hardness (Shore) |
Temp. Range (°C) |
|---|---|---|---|---|---|
|
EX4481-35 |
Deep Blue Paste |
S14 10rpm:47,000–70,500 1rpm:272,000–408,000 |
2,000~6,000 mJ/cm2 |
D 70 ± 3 |
-40~100 |
|
EX4481-15-F |
Blue Paste |
S14 20rpm:13,000–21,000 |
1,000~2,000 mJ/cm2 |
D 56 |
-40~100 |
|
5867 |
Black Paste |
S14 10rpm:27,000–42,000 |
1,000~2,000 mJ/cm2 |
D 52 |
-20~80 |
|
58051 |
Blue Fluor. Paste |
S14 10rpm:15,000–30,000 100rpm:7,500–15,000 |
1,500–2,000mJ/cm2 (UV+Moisture) |
D 6 → 57 (1–9 Days) |
-20~100 |
|
EXA-603-21 |
Mist White Paste |
S14 20rpm:16,500–30,500 |
1,500~3,000 mJ/cm2 |
D 68 ± 2 |
-40~120 |
|
EXA-603-21-4 |
Mist White Paste |
S14 10rpm:16,000–24,000 |
1,000~2,000 mJ/cm2 |
D 63 ± 2 |
-40~120 |
|
EXA-603-21-4M |
Mist White Paste |
S14 10rpm:16,000–24,000 |
1,000~2,000 mJ/cm2 |
D 63 ± 2 |
-40~120 |
|
EXA-603-21-4F1 |
Mist White Paste |
S14 10rpm:16,000–24,000 |
1,000~2,000 mJ/cm2 (Fluor. Inspect.) |
D 63 ± 2 |
-40~120 |
|
EXA-603-21-6 |
Milky Liquid |
S14 10rpm:19,500–29,500 |
1,000~2,000 mJ/cm2 |
D 65 ± 2 |
-40~120 |
D. Lens Module / Active Alignment & Focus Fixing
| Model | Color |
Viscosity (cps) |
UV Energy |
Hardness (Shore) |
Temp. Range (°C) |
|---|---|---|---|---|---|
|
5800H1 |
Mist White Paste |
S14 20rpm:13,000–20,000 2.5rpm:48,000–72,000 |
800–1,000 mJ/cm2 (Depth 0.25″) |
D 80 |
-40~80 |
|
5254 |
Clear Paste |
S14 10rpm 80,000–120,000 |
1,000–2,000 mJ/cm2 |
D 66 ± 2 |
-40~100 |
|
5867 |
Black Paste |
S14 20rpm:13,000–21,000 |
1,000–2,000 mJ/cm2 |
D 52 |
-20~80 |
|
HV054-4 |
Clear Paste |
S14 10rpm:20,000–30,000 1rpm:118,200–177,400 |
1,500–3,000 mJ/cm2 (Avoid Over-exposure) |
D 45 |
-40~100 |
E. Optical Components / Low Shrinkage (Cationic Epoxy)
| Model | Color |
Viscosity (cps) |
UV Energy | Secondary Cure (Thermal) |
Hardness (Shore) |
Temp. Range (°C) |
|---|---|---|---|---|---|---|
|
5857 |
Black Paste |
S14 10rpm:100,000–150,000 （Ti≧4） |
3,000–6,000 mJ/cm2 |
85°C for 45 min OR 120°C for 30 min |
D 92 volume shrinkage of 0.95% |
-40~120 |
|
5858 |
Off-white Liquid |
S14 100rpm:1,900–2,900 |
1,500–3,000 mJ/cm2 |
80°C for 1 hr |
D 90 volume shrinkage of 6–7% |
-20~100 |
F. Color Change / Visual Inspection / Rework
| Model | Color |
Viscosity (cps) |
UV Energy |
Hardness (Shore) |
Temp. Range (°C) |
|---|---|---|---|---|---|
|
58037 |
Red Liquid |
S14 10rpm:20,000–30,000 |
1,500–2,000 mJ/cm2 |
A 60 |
-40~80 |
|
58034 |
Red Liquid |
S14 10rpm:20,000–30,000 |
1,500–2,000 mJ/cm2 |
A 60 |
-40~100 |
|
58037-12N |
Clear Paste |
S14 50rpm:8,200–10,800 |
1,500–2,000 mJ/cm2 |
A 37 ± 2 |
-20~80 |
|
EXA603-21-4F1 |
Mist White Paste |
S14 10rpm:16,000–24,000 |
1,000–2,000 mJ/cm2 |
D 63 ± 2 |
-40~100 |
G. Peelable / Rework & Bezel Airtight Sealing
| Model | Color |
Viscosity (cps) |
UV Energy |
Hardness (Shore) |
Temp. Range (°C) |
|---|---|---|---|---|---|
|
58596 |
Mist White Paste |
S14 10rpm:15,000–35,000 (Ti2.0–3.5) |
1,500–3,000 mJ/cm2 |
A 22 |
-40~80 |
|
85001 |
Mist White Paste |
S14 10rpm:15,000–35,000 (Ti2.0–3.5) |
1,500–3,000 mJ/cm2 |
A 22 ± 2 |
-40~80 |
Notes:
- The values above are for reference only; actual values are based on the Certificate of Analysis (COA) of the shipped batch.