Thermally Conductive-Fire Resistant Silicone
Silicone dielectric potting and encapsulating compounds with high thermal conductivity and excellent fire resistance properties – for electronic and aerospace applications.
THERMASIL – TYPE I , IX
One–part system – ready to use
THERMASIL – TYPE II
Two-part system-low temperature cure
- High tensile strength
- High temperature characteristics
- Fire resistant. Self extinguishing
- High thermal conductivity
- Excellent electrical properties
Thermasil is a specially processed silicone rubber composition, fire-resistant and non-combustible, designed for thermally conductive potting and encapsulating of electronic equipment. Thermasil is solventless, containing 100% reactive material. Cured simply by heating, Thermasil forms a flexible, heat resistant silicone rubber. It will withstand temperatures in excess of 275 °C. Electrical properties are not sacrificed.
Properties of Thermasil
|Type I||Type II||Type IX|
|Viscosity@ 23 °C (cps)||130,000 ± 10%||140,000 ± 10%||200,000± 10%|
|Sp.Gr @ 25 °C||2.25||2.03||2.25|
|Shelf Life||6 months||6 months||6 months|
|Storage||40 °F or lower||Room Temp||40 °F or lower|
|Hardness_Dur Shore A||75-85||55-65||75-85|
|Tensile strenght (psi)||600||600||600|
|Elongation %||> 100||> 100||> 100|
|Thermal expansion in/in/°F||35 x 10-6||35 x 10-6||35 x 10-6|
|Operating Temp. Range °C||-50 to 250 (Cont)||-50 to +250 (Cont)||-50 to 250 (Cont)|
|Brittle Point °C||-55||-55||-55|
25 °+C @ 1KHz
|Dielectric Strength (v/mil)
1 16 sample
|Volume Resistivity (ohm-cm) 500 V,dc||1 x 1016||1 x 1015||1 x 1016|
|(spindle 7, 20 rpm, Brookfield HAT)|
Any one of the following:
|Thermasil I/IX||Catalyst Conc.||Pot Life||Cure Time (hrs)
|100 °C – 4 hours||5% Catalyst S> 1 hour||100 °C – 4 hours||15||4||2|
|125 °C – 1 ½ hours||10% Catalyst S> ½ hour||125 °C – 1 ½ hours||12||2||1|
|150 °C – 1 hour||5% Catalyst T 3 hours||150 °C – 1 hour||30||6||3|
Thermasil is recommended as a protective coating for electronic components from which heat is to be dissipated and where fire resistance is of prime importance, and also as a “form-in place” heat sink. It is useful as a conformal coating for electronic assemblies which must operate at high temperature and voltage conditions, as well as for power resistors, cables and connectors.
Among the advantages of Thermasil conformal coatings are: protection against corrosion and humidity, Class H insulation, high electrical insulation and stability, mechanical support, and an operating temperature range from -65 °C to + 275 °C. Application is by dipping, painting or potting followed by recommended heat cure.
Thermasil IX, 1 pound kit, corresponds to National Stock Number (NSN) 8030-01-105-8605. Thermasil II, 1 pound kit with Catalyst S, corresponds to National Stock Number 8040-01-105-8604.