Aerospace & Defense.
Electronics in drones, aircraft, and defense technology must withstand vibration, wide temperature ranges, various media, and electromagnetic interference. This page presents the silicone protection methods available for this purpose, from potting and encapsulation to sealing, bonding, and coating, along with the appropriate materials from Elkem Bluesil and CAF. Available from stock in Gümligen, with technical advice and datasheets.
On this page
Requirements · Protection methods · Materials · Selection guide · Selection criteria · Processing · FAQ · Further information
Operating conditions
What these missions demand
Components in drones, aircraft, and military technology rarely fail at the component itself, but rather due to their environment. Usually, multiple stresses act simultaneously over extended periods of operation. The appropriate protection method begins with understanding these relevant stresses.
- Vibration and shock: Continuous vibration and impacts put stress on solder joints, wires and connectors.
- Wide temperature ranges: from extremely cold to extremely hot, with changes and different expansion of the materials.
- Moisture and media: condensation, fuels, hydraulic oil, cleaners and salt spray.
- Heat: Waste heat must be dissipated, otherwise the lifespan decreases.
- Electric fields and EMC: Insulation for high voltage, shielding for sensitive electronics.
- Lightweight construction: Protection level and weight must be weighed against each other.
Methods and materials
Protection methods using our silicones
Six methods, each using materials from our product range. They can be combined.
Potting & Encapsulation
Bluesil RTV 147/148
Embedding the assembly against vibration, moisture, and media. High-temperature resistant, encapsulating RTV-2 silicones such as Bluesil RTV 147 and RTV 148. RTV-2 silicones.
Sealing & Bonding
CAF series and primers
Formed-in-place gaskets and flexible bonding over a wide temperature range, using RTV-1 silicones from the CAF series and suitable primers. Adhesives & Sealants.
Conformal Coating
Bluesil Resine 991
Thin, lightweight protective film for printed circuit boards against moisture and leakage currents. Silicone protective coating Bluesil Resine 991. Silicone products.
Thermal management
thermally conductive pastes
Dissipation of heat loss using thermally conductive silicone pastes and potting compounds, such as Bluesil Paste 340. The lambda value is product-dependent and can be found in the data sheet. Silicone products.
Electrical insulation
high dielectric strength
Silicones with high dielectric strength and good volumetric resistance for power and high-voltage electronics. Specifications as per datasheet. Energy & High Voltage.
EMI/RFI shielding
conductive coatings
Conductive coatings shield against electromagnetic interference and establish a ground connection. Shielding attenuation depends on the product. Surface treatment.
materials
Materials overview
Which material for what purpose? Specific specifications are product-dependent and can be found in the data sheet.
| method | Material from the product range | function |
|---|---|---|
| Potting & Encapsulation | Bluesil RTV 147 / RTV 148 (RTV-2) | Protection against vibration, moisture and media, good dielectric properties |
| Sealing & Bonding | CAF series (RTV-1) plus Primer 131 / PM 820 | Formed-in-place seal and flexible bonding |
| Conformal Coating | Bluesil Resine 991 | thin, lightweight protective film on printed circuit boards |
| Thermal management | Thermally conductive pastes (e.g. Bluesil Paste 340) | Dissipation of waste heat |
| EMI/RFI shielding | conductive coatings | Shielding and ground contact |
Silicone offers a wide temperature range, self-extinguishing fire behavior, good dielectric properties, and low ion content. The method details (coating, encapsulation, encapsulation, thermal management, insulation) are explained on the page "Protecting Electronics" .
Decision
Selection aid
| Requirement | More suitable | Notice |
|---|---|---|
| Maximum protection against vibration and media | Full casting, RTV-2 (Bluesil RTV 147/148) | Adjust stiffness to component load |
| Lightweight, repairable basic protection | Conformal coating (Bluesil Resine 991) | lightweight, thin layer |
| Flexible sealing and joining | RTV-1 of the CAF series plus primer | Formed-in-place, wide temperature range |
| Dissipate waste heat | thermally conductive paste or potting compound | Lambda value according to data sheet |
| High voltage and insulation | Silicone with high dielectric strength | Key figures according to data sheet and standard |
| Shielding against interference fields | conductive coating | Shielding attenuation depends on the product |
Key factors include materials, geometry, load, temperature, media, and weight. Specific parameters can be found in the respective technical data sheet.
specification
What you should clarify before making your selection
- Geometry and layer thickness: full encapsulation, encapsulation or thin coating.
- Stress factors: vibration, shock, and how sensitive the components are to stress.
- Temperature: Continuous and peak temperature as well as temperature changes.
- Media: Moisture, fuels, oils, cleaners, salt spray.
- Heat: if significant power loss occurs, a thermally conductive solution is needed.
- Electrical: voltage level, required dielectric strength, EMC.
- Repairability and weight: must the assembly remain accessible, how much additional weight is acceptable?
- Processing: Dosage, pot life, curing, quantity.
Using this information, we will jointly narrow down suitable products and review the data sheets.
processing
Process cleanly
- Pretreatment: clean, dry surfaces; primer required for adhesion.
- Mixing: When using 2K systems, adhere precisely to the mixing ratio.
- Degassing: Removing air inclusions in a vacuum, especially at high voltage.
- Curing: Pot life and curing conditions according to the data sheet.
- Note the inhibition: platinum-curing silicones do not harden on contact with tin, sulfur or amines; test if in doubt.
FAQ
Frequently Asked Questions
Full potting or conformal coating?
Coating for lightweight, repairable basic protection against moisture at minimal weight. Full encapsulation when maximum protection against media and vibration is required and the additional weight is acceptable.
What does FIPG mean in the context of CAF silicones?
Formed-in-place gasket: the gasket is applied in liquid form to the flange and hardens there to form a seal, instead of using a pre-made gasket. RTV-1 silicones from the CAF series are suitable for this.
Which silicone is suitable for encapsulating electronics?
High-temperature resistant RTV-2 encapsulants such as Bluesil RTV 147 and RTV 148 are commonly used for this purpose. The appropriate type depends on temperature, geometry, and media contact; the specifications can be found in the datasheet.
How is heat dissipated?
Via thermally conductive silicone pastes or potting compounds, such as Bluesil Paste 340. The lambda value in W/mK is product-dependent and can be found in the data sheet.
On which surfaces do silicones adhere?
Suitable for many metals and plastics, often with a suitable primer such as Bluesil Primer 131 or PM 820. A preliminary test is advisable for critical substrates.
Further information
Suitable products, worlds, applications & industries
Product groups: Silicone products · RTV-2 silicones · Adhesives & sealants · Surface treatment
Themes: Silicones · Potting & Electronic Protection
Application in detail: Protecting electronics (protection methods, material comparison, processing)
Industries: Aerospace · Defense & Security · Electronics & Printed Circuit Boards · Energy & High Voltage
Terms: in the glossary (potting, conformal coating, FIPG, dielectric strength, lambda value, EMI).
Technical basis: Information provided is for general guidance only and does not constitute a product guarantee. The manufacturer's data sheets (TDS), their specifications, and relevant standards are binding. Specific characteristics (temperature range, dielectric strength, lambda value, pot life) are product-dependent.
contact
Which silicone is suitable for your assembly?
Describe the setup, environment, and load requirements to us. We will suggest suitable materials, review the technical data sheets, and deliver from our warehouse in Gümligen.