LOCTITE 3872
Harmonization Code : 3506.91.90.99 | Prepared glues and other prepared adhesives, not elsewhere specified or included; products suitable for use as glues or adhesives, put up for retail sale as glues or adhesives, not exceeding a net weight of 1 kg ; Adhesives based on polymers of headings 3901 to 3913 or on rubber; Other ; Other
Main features
- Self-Shimming Thermal Bondline
- UV Fixture Before Heat Cure
- Low-Modulus Thermal Attachment
Product Description
LOCTITE 3872 combines a one-part acrylic-urethane adhesive with glass-sphere bondline control for thermal attachment of heat-generating devices. Solid spheres establish a 0.127 mm bondline, and UV fillet curing provides rapid fixturing before the required heat-cure step. The cured material has a typical thermal conductivity of 1.20 W/(m K), a glass transition temperature of -33 deg C, and Shore D 71 hardness after the stated cure. Its operating-temperature range is -54 to 150 deg C. Applications include bonding power devices to heat sinks, including silicon chips to metal lead frames.
Key features
- Self-Shimming Bondline: Solid glass spheres establish a uniform 0.127 mm bondline.
- Thermal Bond Performance: Typical cured thermal conductivity is 1.20 W/(m K).
- UV Fixture Before Heat Cure: UV fillet cure fixtures parts before the full heat-cure step.
Applications
Applications include bonding heat-generating devices to heat sinks, including silicon chips to metal lead frames.
Technical Specifications
General Properties
Physical Properties
Thermal Properties
Mechanical Properties
Electrical Properties
Additional Information
As-Supplied Properties
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Appearance | Light grey, thick dispersion | - | Uncured |
| Specific gravity | 2.50 | - | 25 deg C |
| Viscosity | 1,200,000 to 2,100,000 | mPa s | Brookfield HBT, spindle TB, 0.5 rpm, helipath, 25 deg C |
| Viscosity | 550,000 | mPa s | Brookfield HBT, spindle TB, 5.0 rpm, helipath, 25 deg C |
| Spacer sphere diameter | 0.127 | mm | Solid glass spheres |
Final-State Properties
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Thermal conductivity | 1.20 | W/(m K) | ASTM E 1225; cured 45 min at 125 deg C |
| Hardness | 71 | Shore D-2 | ASTM D 2240; cured 45 min at 125 deg C |
| Tensile strength at break | 3.70 | N/mm^2 | Cured 45 min at 125 deg C |
| Elongation at break | 30 | % | Cured 45 min at 125 deg C |
| Young's modulus | 117 | N/mm^2 | Cured 45 min at 125 deg C |
| Glass transition temperature | -33 | deg C | Cured 45 min at 125 deg C |
| Dielectric strength | 23.62 | kV/mm | ASTM D 149; cured 45 min at 125 deg C |
| Operating temperature | -54 to 150 | deg C | Product operating range |
