DOWSIL 93-500
Harmonization Code : 3910.00.00.90 | Silicones in Primary Forms; Others
Main features
- Low-Outgassing Vacuum Bonding
- 2.5-Hour Working Window
- Flexible Cured Adhesive
Product Description
DOWSIL™ 93-500 Space Grade Encapsulant is a transparent, flowable, two-part addition-cure silicone elastomer for encapsulating, potting, bonding, sealing, and coating electronic and optical assemblies used in terrestrial and space systems. The base and curing agent are mixed 10:1 by weight, providing a typical 2.5-hour pot life and room-temperature or heat-accelerated cure options. After cure, the material forms a flexible rubber with a documented -115 to 200°C operating range, low thermal-vacuum outgassing, and stable mechanical and electrical properties. It is documented for PCB components and assemblies, modules, relays, connectors, solar-cell and optical assemblies, sensors, seals, and selected thermal-control coating uses.
Key features
- Low thermal-vacuum outgassing: Typical thermal vacuum weight loss is 0.20%, with 0.01% volatile condensable material under the stated vacuum test conditions.
- Wide operating temperature range: The cured material has a documented operating range from -115 to 200°C (-149 to 392°F).
- Electrical insulation after cure: Typical cured values include 480 V/mil dielectric strength and 1.0 × 1015 ohm-cm volume resistivity.
Applications / Suitable for
- Encapsulation and potting of PCB components, circuit boards, assemblies, modules, relays, and connectors
- Bonding of solar cells, cover glasses, OSR mirrors, PCB subcomponents, optical sensors, and other sensors
- Fay and fillet seals, formed-in-place gaskets, optical sensor seals, and selected thermal-control coating applications
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Physical Properties
Mechanical Properties
Thermal Properties
Electrical Properties
Additional Information
DOWSIL™ 93-500 Space Grade Encapsulant
DOWSIL™ 93-500 is a transparent, flowable, two-part silicone encapsulant developed for space-system, PCB, and optical assemblies where low thermal-vacuum outgassing is important. It cures to a flexible elastomer with a documented -115 to 200°C operating range and combines mechanical protection functions with electrical insulation properties for encapsulation, potting, bonding, sealing, and coating applications.
Product image: DOWSIL™ 93-500 Space Grade Encapsulant base and curing-agent kit.
As-supplied properties
Mixing, de-airing, and cure
Prepare the substrate, mix the two components at the specified weight ratio, remove entrapped air, and select a room-temperature or heat-accelerated cure that fits the part geometry.
Store below 32°C (90°F) with containers tightly closed. Shelf life is controlled by the “Use Before” date on the product label. Complete kits contain separate base and curing-agent containers and are available in 3.9 oz (110 g) and 1.1 lb (0.5 kg) net weights.
Compatibility and adhesion guidance
Store below 32°C (90°F) with containers tightly closed. Shelf life is controlled by the “Use Before” date on the product label. Complete kits contain separate base and curing-agent containers and are available in 3.9 oz (110 g) and 1.1 lb (0.5 kg) net weights.
Compatibility and adhesion guidance
Typical cured properties
Typical values are not intended for use in preparing specifications. Unless otherwise stated, properties are reported after 7 days of cure at 25°C (77°F) and 50% relative humidity.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Refractive index | 1.41 | — | Cured 7 days at 25°C (77°F) and 50% RH |
| Durometer | 40 | Shore A points | Cured 7 days at 25°C (77°F) and 50% RH |
| Tensile strength | 975 | psi | Cured 7 days at 25°C (77°F) and 50% RH |
| Elongation | 170 | % | Cured 7 days at 25°C (77°F) and 50% RH |
| Tear strength | 15 | ppi | Die B; cured 7 days at 25°C (77°F) and 50% RH |
| Lap shear | 475 | psi | Primed aluminum; cured 7 days at 25°C (77°F) and 50% RH |
| Thermal vacuum weight loss | 0.20 | % | 24 hours at 125°C (257°F) and <1 × 10-6 torr |
| Volatile condensable material | 0.01 | % | Collected at 25°C (77°F) during the vacuum weight-loss test |
| Linear coefficient of thermal expansion | 300 | micron/m·°C | Cured 7 days at 25°C (77°F) and 50% RH |
| Thermal conductivity | 0.20 | W/m·°C | Cured 7 days at 25°C (77°F) and 50% RH |
| Dielectric strength | 480 | V/mil | Cured 7 days at 25°C (77°F) and 50% RH |
| Volume resistivity | 1.0 × 1015 | ohm-cm | Cured 7 days at 25°C (77°F) and 50% RH |
| Dielectric constant | 2.6 | — | 100 Hz; cured 7 days at 25°C (77°F) and 50% RH |
| Dielectric constant | 2.6 | — | 100 kHz; cured 7 days at 25°C (77°F) and 50% RH |
| Dissipation factor | 0.0011 | — | 100 Hz; cured 7 days at 25°C (77°F) and 50% RH |
| Dissipation factor | 0.0002 | — | 100 kHz; cured 7 days at 25°C (77°F) and 50% RH |
Applications
DOWSIL™ 93-500 is documented for encapsulation, bonding, sealing, and coating tasks in terrestrial and space-system electronics and optical assemblies.
Evaluate DOWSIL™ 93-500 for your application
Need help evaluating DOWSIL™ 93-500 for an aerospace, PCB, optical, or space-system assembly? Krayden can help review application geometry, substrate preparation, cure compatibility, processing conditions, and the relevant thermal-vacuum, mechanical, and electrical data for your design.
