COOLTHERM SC-6705
Harmonization Code : 3910.00.00.90 | Silicones in Primary Forms; Others
Main features
- 55 to 205 deg C Service Range
- 2,500 cP Mixed Viscosity
- 17.7 kV/mm Dielectric Strength
Product Description
CoolTherm® SC-6705 Silicone Encapsulant is a two-component, addition-cure silicone system designed for applications requiring flexible encapsulation and high-temperature service. The resin and hardener mix at a 1:1 ratio by weight or volume to form a black liquid with a typical mixed viscosity of 2,500 cP at 25°C. After cure, the material forms a flexible elastomer with a documented operating-temperature range of -55°C to +205°C, typical thermal conductivity of 0.35 W/m·K, and electrical insulating properties.
Key features
- Broad operating-temperature range: Suitable for parts and devices operating from -55°C to +205°C.
- Low mixed viscosity: Provides a typical mixed viscosity of 2,500 cP at 25°C for encapsulation processing.
- Flexible electrical insulation: The cured system provides 100% elongation at break, typical dielectric strength of 17.7 kV/mm, and volume resistivity of 1 × 1014 ohm-cm at 25°C.
Applications / Suitable for
- Flexible silicone encapsulation requiring high-temperature service
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Appearance
Resin: Black Liq | Hardener: Off white Liq | Mixed: Black Liq
Appearance at room temperature.
Specific Gravity
1.35
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 (Part A)
(Resin) 3000 mPa.s
Viscosity (Part B)
(Hardener) 2900 mPa.s
Thermal Properties
Thermal Conductivity
0.35 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.
Mechanical Properties
Elongation
at break 100 %
Elongation is the process of lengthening something.
It is a percentage that measures the initial, unstressed, length compared to the length of the material right before it breaks.
It is commonly referred to as Ultimate Elongation or Tensile Elongation at break.
Electrical Properties
Dielectric Strength
17.7 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.
Volume Resistivity
1 x 10^14 Ohms⋅cm
Volume resistivity, also called volume resistance, bulk resistance or bulk resistivity is a thickness dependent measurement of the resistivity of a material perpendicular to the plane of the surface.
Additional Information
Technical properties
As-supplied / before-processing properties
Typical properties of CoolTherm SC-6705 resin, hardener, and mixed encapsulant before cure. Values are not intended for specification purposes.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Appearance | Black liquid / Off-white liquid / Black liquid | — | Resin / hardener / mixed system |
| Viscosity | 3,000 / 2,900 / 2,500 | cP | Resin / hardener / mixed system at 25°C; test method not stated |
| Specific gravity | 1.35 / 1.35 / 1.35 | — | Resin / hardener / mixed system; test conditions not stated |
| Mix ratio | 1:1 | Resin:hardener | By weight or volume |
| Working life | 1–2 | hours | Mixed system at 25°C; endpoint definition and test method not stated |
| Cure schedule | 2 hours / 24 hours | — | At 65°C / room temperature; time begins after the material reaches the target temperature |
| Shelf life | 6 | months | Each component when stored at 25°C in the original, unopened container |
Technical properties
After-processing / final-state properties
Typical cured properties of CoolTherm SC-6705 Silicone Encapsulant. The source does not state the cure schedule used to prepare the cured-property specimens. Values are not intended for specification purposes.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Operating temperature range | -55 to +205 | °C | Documented range for parts and devices; retained-property data are not stated |
| Thermal conductivity | 0.35 | W/m·K | Test method and temperature not stated |
| Hardness | 60 | Shore A | Test method not stated |
| Tensile strength | 2.07 (300) | MPa (psi) | Test method and test temperature not stated |
| Elongation at break | 100 | % | Test method and test temperature not stated |
| Volume resistivity | 1 × 1014 | ohm-cm | At 25°C; ASTM D257 |
| Dielectric strength | 17.7 (450) | kV/mm (V/mil) | ASTM D149; specimen thickness not stated |
| Dielectric constant | 3.2 | — | At 100 Hz; ASTM D150 |
| Dissipation factor | 0.005 | — | At 100 Hz; ASTM D150 |
