LOCTITE 3873
Harmonization Code : 3506.10.00.00 | 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
Main features
- Controlled 0.127 mm Thermal Bondline
- Thermally Conductive Permanent Attachment
- Activator-Cure Power-Device Bonding
Product Description
LOCTITE 3873 uses a one-part, high-viscosity acrylic ester formulation with 0.127 mm glass spheres to create a controlled thermal bondline. It cures with separately applied LOCTITE Activator 7387 and develops a high-modulus thermoset bond for power-device attachment. Typical cured thermal conductivity is 1.25 W/(m K), with Shore D 72 hardness and a 49 deg C glass transition temperature under the stated cure conditions. The self-shimming format is suited to bonding heat-generating devices to thermal spreaders where controlled bondline thickness and permanent attachment are required.
Key features
- Controlled 0.127 mm Bondline: Solid glass spheres establish the self-shimming bondline thickness.
- Thermally Conductive Attachment: Typical cured thermal conductivity is 1.25 W/(m K).
- Activator-Cure Power Bonding: LOCTITE Activator 7387 initiates cure for power-device attachment.
Applications
Applications include bonding heat-generating and power devices to thermal spreaders or similar heat-management structures.
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Physical Properties
Other Properties
Thermal Properties
Mechanical Properties
Electrical Properties
Additional Information
As-Supplied Properties
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Appearance | Light grey opaque thixotropic fluid with no visible bubbles | - | Uncured |
| Specific gravity | 2.08 | - | 25 deg C |
| Viscosity | 750,000 to 2,000,000 | mPa s | Brookfield HBT, spindle TB, 0.5 rpm, helipath, 25 deg C |
| Viscosity | 200,000 to 600,000 | 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 |
|---|---|---|---|
| Coefficient of thermal expansion | 76 x 10^-6 | K^-1 | ISO 11359-2; cured 24 h at 70 deg C, then 2 days at room temperature |
| Glass transition temperature | 49 | deg C | Cured 24 h at 70 deg C, then 2 days at room temperature |
| Thermal conductivity | 1.25 | W/(m K) | ISO 8302; cured 24 h at 70 deg C, then 7 days at room temperature |
| Hardness | 72 | Shore D | ISO 868; cured 24 h at 70 deg C, then 7 days at room temperature |
| Elongation at break | 3.2 | % | ISO 527-3; cured 24 h at 70 deg C, then 7 days at room temperature |
| Tensile strength at break | 9.7 | N/mm^2 | ISO 527-3; cured 24 h at 70 deg C, then 7 days at room temperature |
| Young's modulus | 850 | N/mm^2 | Cured 24 h at 70 deg C, then 7 days at room temperature |
| Dielectric breakdown strength | 23.62 | kV/mm | IEC 60243-1; cured at room temperature |
