PERMABOND ES578
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
- 1.0 W/(m K) Thermal Conductivity
- Heat-Activated Flow for 5 mm Gaps
- UL 94 V-0 Classification
Product Description
Permabond® ES578 is a high-performance, single-part epoxy adhesive designed to deliver both exceptional bond strength and very good thermal conductivity. Formulated to flow when heated during the cure cycle, it readily fills gaps and ensures optimal contact area for heat transfer. This combination of structural strength, thermal dissipation, and electrical insulation makes it ideal for specialized applications such as bonding aluminum heat sinks to ceramic headers.
Key features
- Thermally conductive: Provides a thermal conductivity of 1.0 W/(m.K) to effectively dissipate heat from critical components.
- Fire retardant: The cured adhesive is specifically engineered to meet the stringent fire retardancy requirements of UL94 V-0.
- Electrically insulating: Delivers high dielectric strength (40-45 kV/mm), making it safe and effective for electronic assemblies.
Applications / Suitable for
- Bonding applications requiring heat dissipation, such as heat sinks to ceramic headers
- Structural bonding of metals, ceramics, and composite materials
- Electronic enclosures requiring UL94 V-0 fire retardancy compliance
Technical Specifications
General Properties
Appearance
Black paste
Appearance at room temperature.
Chemistry Type
Epoxy
Solids
100 %
Specific Gravity
1.6
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.
Physical Properties
Viscosity
600,000 to 800,000 0 mPa.s
Viscosity is a measurement of a fluid’s resistance to flow.
Viscosity is commonly measured in centiPoise (cP). One cP is defined as
the viscosity of water and all other viscosities are derived from this base. MPa is another common unit with a 1:1 conversion to cP.
A product like honey would have a much higher viscosity -around 10,000 cPs-
compared to water. As a result, honey would flow much slower out of a tipped glass than
water would.
The viscosity of a material can be decreased with an increase in temperature in
order to better suit an application
Thermal Properties
Glass Transition Temperature (Tg)
105 °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.
Thermal Conductivity
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.
Electrical Properties
Dielectric Strength
40-45 kV/mm
Dielectric strength is measured in kV per mm and is calculated by the Breakdown voltage divided by the thickness of the tested material.
Those two properties go hand in hand and while Breakdown voltage is always thickness dependent, dielectric strength is a general material property.
As an example, the dielectric strength of Polyimide is 236 kV/mm. If we place 1mm of Polyimide between two electrodes, it will act as an insulator until the voltage between the electrodes reaches 236 kV. At this point it will start acting as a good conductor, causing sparks, potential punctures and current flow.
Other Properties
Maximum gap fill
5 mm
Additional Information
Technical properties
As-supplied / before-processing properties
Typical properties; these values are not intended for use in preparing specifications.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Chemical Composition | Epoxy Resin | - | - |
| Appearance | Black | - | Paste |
| Viscosity | 600,000 to 800,000 | cP | at 25°C (mPa.s) |
| Specific Gravity | 1.6 | - | - |
| Maximum Gap Fill | 5 | mm | (0.2 in) |
| Flash Point | > 100 | °C | - |
Technical properties
After-processing / final-state properties
Typical properties; these values are not intended for use in preparing specifications.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Flow at High Temperature | Flowing | - | - |
| Cure Speed | < 3 | minutes | Induction |
| Cure Speed | 75 | minutes | Oven at 130°C (266°F) |
| Cure Speed | 60 | minutes | Oven at 150°C (300°F) |
| Cure Speed | 25 | minutes | Oven at 170°C (338°F) |
| Shear Strength | 27-41 | N/mm² | Steel (ISO 4587) (4000-6000 psi) |
| Shear Strength | 7-31 | N/mm² | Aluminium (2500-4500 psi) |
| Shear Strength | 4-27 | N/mm² | Zinc (2000-4000 psi) |
| Hardness | 80-85 | Shore D | ISO 868 |
| Dielectric Strength | 40-45 | kV/mm | - |
| Coefficient of Thermal Expansion | 45E-6 | mm/mm/°C | (below Tg) |
| Thermal Conductivity | 1.0 | W/(m.K) | - |
| Glass Transition Temperature (Tg) | 105 | °C | (220°F) DSC |
