November 10, 2026 HT-1331S Surface Mount Adhesive Solution
HT-1331S is a high-viscosity, one-component, intermediate-temperature, fast heat-curable surface mount adhesive engineered for high-speed dispensing and screen printing applications. Manufactured by MacDermid Alpha, this epoxy-based red paste provides exceptional productivity in wave-soldering processes. Electronics manufacturers select HT-1331S for securing surface-mount components precisely on printed circuit board (PCB) assemblies prior to wave soldering.
Key Features and Benefits of HT-1331S
This high-performance surface mount adhesive delivers a balanced set of processing and mechanical properties tailored for demanding SMT manufacturing lines:
- Fast Heat Curing: Rapidly cures at intermediate temperatures, such as 80 seconds at 150 °C in a convection oven.
- Controlled High Viscosity: Features a viscosity of 900 to 1,200 Poise (Malcom PC-1TL @ 25 °C) to maintain stable dot shapes under high dispensing pressure.
- Excellent Thermal Resistance & Tg: Exhibits a high glass transition temperature (Tg ≥ 110 °C) and maintains structural integrity during wave soldering.
- High Electrical Insulation: Delivers superior insulation resistance (≥ 1 x 10¹² Ω) and zero corrosion after extended humidity testing.
- Non-Sagging & Low Moisture Absorption: High thixotropic index (≥ 3.0) prevents slumping, while moisture absorption stays under ≤ 1.0 wt%.
Processing Guidelines and Curing Conditions
Applying HT-1331S on assembly lines enables operators to achieve consistent dot geometry and high production speeds. Uncured, this red paste exhibits a viscosity of 900 to 1,200 Poise (Malcom PC-1TL, 30 rpm @ 25 °C), a pot life of 7 days at 25 °C, and a shelf life of 6 months when stored between 1 and 10 °C. Recommended cure conditions in a convection oven require a profile of 80 seconds at 150 °C, though optimal conditions may vary based on equipment and board mass.
Technical Specifications
| Category / Parameter | Specification Details |
|---|---|
| Chemistry & Appearance | Epoxy (Red paste) |
| Application Methods | High-speed Dispenser & Screen Print |
| Viscosity @ 25 °C | 900 to 1,200 Poise (Malcom PC-1TL, 30 rpm) |
| Thixotropic Index / Specific Gravity | ≥ 3.0 / 1.0 to 1.4 |
| Pot Life / Shelf Life | 7 days @ 25 °C / 6 months @ 1 to 10 °C |
| Convection Oven Curing Profile | 80 seconds @ 150 °C |
| Glass Transition Temp (Tg) / Hardness | ≥ 110 °C (DSC) / 80 to 90 (Shore D) |
| CTE (TMA) | α1 (<Tg): 65 (±10) ppm / α2 (>Tg): 180 (±20) ppm |
| Electrical Insulation & Corrosion | Insulation Resistance ≥ 1 x 10¹² Ω; Corrosion: None |
Conclusion
In summary, HT-1331S provides a fast-curing, high-viscosity surface mount adhesive solution tailored for wave-soldering operations in high-density electronics manufacturing. For technical datasheets, commercial quotes, or product support, please contact us via Contact – LORIOT INDUSTRIAL.
