ABLESTIK 2156
Harmonization Code : 5906100000 | Adhesive tape of a width not exceeding 20cm
Main features
- 0.84 W/(m K) Thermal Conductivity
- Heat-Sensitive Component Staking
- -70 to 100 deg C Operating Range
Product Description
LOCTITE® ABLESTIK 2156 BIPAX is a two-component, thermally conductive and electrically insulating epoxy adhesive for staking and assembly applications. The tan, thixotropic system mixes at 100:23 resin-to-hardener by weight and is designed to develop strong, impact-resistant bonds through room-temperature or accelerated heat cure. It is documented for staking heat sinks, transistors, diodes, resistors, integrated circuits, and other heat-sensitive components to printed circuit boards and for bonding metals, silica, alumina, sapphire, ceramics, glass, and plastics. The mixed adhesive has a typical viscosity of 12,000 mPa·s at 25°C and a five-minute pot life.
Key features
- Thermally conductive and electrically insulating: Typical cured thermal conductivity is 0.84 W/(m·K).
- Thixotropic, high-impact adhesive: Supports controlled placement and strong bonding in electronic-component staking applications.
- Room-temperature or accelerated cure: Guideline schedules include 24 hours at 25°C or 1 hour at 25°C followed by 2 hours at 65°C.
Applications / Suitable for
- Staking heat sinks and heat-sensitive components to printed circuit boards
- Staking transistors, diodes, resistors, and integrated circuits
- Bonding metals, glass, plastics, and ceramics
- Bonding silica, alumina, and sapphire
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Appearance
Tan
Appearance at room temperature.
Chemistry Type
Epoxy
Mix Ratio
100 : 23
The amount of a constituent divided by the total amount of all other constituents in a mixture
Pot Life
5 minutes
Pot life is the amount of time it takes for the viscosity of a material to double (or quadruple for lower viscosity materials) in room temperature after a material is mixed.
It is closely related to work life but it is not application dependent, less precise and more of a general indication of how fast a system is going to cure.
Specific Gravity
2.3
Specific gravity (SG) is the ratio of the density of a substance to the density of a reference substance; equivalently, it is the ratio of the mass of a substance to the mass of a reference substance for the same given volume.
For liquids, the reference substance is almost always water (1), while for gases, it is air (1.18) at room temperature. Specific gravity is unitless.
Thermal Properties
Glass Transition Temperature (Tg)
33 °C
The glass transition temperature for organic adhesives is a temperature region where the polymers change from glassy and brittle to soft and rubbery. Increasing the temperature further continues the softening process as the viscosity drops too. Temperatures between the glass transition temperature and below the decomposition point of the adhesive are the best region for bonding.
The glass-transition temperature Tg of a material characterizes the range of temperatures over which this glass transition occurs.
Operating Temperature
-70 to 100 °C
Thermal Conductivity
8.40×10⁻¹ W/m.K
Thermal conductivity describes the ability of a material to conduct heat. It is required by power packages in order to dissipate heat and maintain stable electrical performance.
Thermal conductivity units are [W/(m K)] in the SI system and [Btu/(hr ft °F)] in the Imperial system.
Additional Information
Technical properties
As-supplied / before-processing properties
Typical component, mixed, storage, and guideline cure information before final processing.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Technology | Epoxy | — | Two-component adhesive requiring mixing |
| Appearance — mixed | Tan | — | Uniformly mixed BIPAX system |
| Appearance — resin | Translucent paste | — | LOCTITE ABLESTIK 2156-R SDS |
| Appearance — hardener | Amber liquid | — | LOCTITE ABLESTIK 2156-H SDS |
| Mix ratio — resin:hardener | 100:23 | by weight | Documented BIPAX mix ratio |
| Mixed viscosity | 12,000 | mPa·s (cP) | Immediately after mixing at 25°C; test method not stated |
| Specific gravity — mixed | 2.3 | — | Typical TDS value |
| Specific gravity — resin | 3.2 | — | LOCTITE ABLESTIK 2156-R SDS |
| Specific gravity — hardener | 1.2 | — | LOCTITE ABLESTIK 2156-H SDS |
| Pot life | 5 | minutes | Temperature, test mass, and endpoint not stated |
| Recommended cure schedule | 24 | hours | At 25°C; guideline recommendation |
| Alternative cure schedule | 1 hour plus 2 hours | — | 1 hour at 25°C followed by 2 hours at 65°C; guideline recommendation |
| Optimal storage | ≤27 | °C | TDS value; component SDSs specify storage at or below 25°C |
Technical properties
After-processing / final-state properties
Typical cured physical, thermal, and bonded-joint properties. Values are reference data and are not product specifications.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Operating-temperature range | -70 to 100 | °C | Documented product range |
| Hardness | 80 | Shore D | Cure condition and test method not stated |
| Glass-transition temperature | 33.0 | °C | Test method and cure condition not stated |
| Coefficient of linear thermal expansion | 26 | ppm/°C | Temperature range, test method, and cure condition not stated |
| Thermal conductivity | 0.84 | W/(m·K) | Test method, test temperature, specimen geometry, and cure condition not stated |
| Reactive solids content | 100 | % | Typical TDS value |
| Lap shear strength — aluminum to aluminum | 23.4 (3,400) | N/mm² (psi) | After curing for 2 hours at 65°C; test temperature, surface preparation, bondline, and test method not stated |
