Silicone Sealants
One-part, two-part & heat-cure RTV
Silicone Sealants
Modern electronics operate in increasingly demanding environments where moisture, thermal cycling, vibration, and contaminants can affect long-term reliability. Silicone sealants provide durable environmental protection, safeguarding sensitive components while maintaining stable performance throughout the product's service life.
With flexibility, strong adhesion, dielectric strength, and resistance to harsh conditions, silicone sealants help improve product reliability, extend service life, and reduce maintenance needs across a wide range of electronic applications.
Available as one-part and two-part RTV systems, as well as heat-cure formulations, silicone sealants are designed for ease of use, efficient processing, and consistent performance in demanding electronic environments.
Product Selector Guide
One-Part RTV Silicone Sealant
| Product | Cure Mechanism | Processing Simplicity | Cure Condition | Throughput Speed | Design Flexibility | Reliability | Best Applications |
|---|---|---|---|---|---|---|---|
| One-Part RTV Silicone Sealant (Dummy Product A) | Moisture-cure (room temperature) | Very high (no mixing required) | Ambient humidity | Medium (fast skin formation, full cure depth-dependent) | Moderate (limited deep-section curing capability) | High long-term environmental stability | PCB coating, LED modules, enclosure sealing, general electronics protection |
Two-Part RTV Silicone Sealant
| Product | Cure Mechanism | Mixing Requirement | Cure Condition | Throughput Speed | Process Control | Depth Cure Capability | Reliability | Best Applications |
|---|---|---|---|---|---|---|---|---|
| Two-Part RTV Silicone Sealant (Dummy Product A) | Room temperature chemical reaction (A/B system) | Yes (controlled ratio) | Ambient (independent of humidity) | Fast (controlled pot life: 10–120 min) | High (defined mixing ratio enables consistent curing) | Excellent (suitable for deep section potting) | Very high long-term electrical and environmental stability | Power modules, potting applications, high-reliability electronics, deep encapsulation |
One-Part Heat-Cure Silicone Sealant
| Product | Cure Mechanism | Mixing Requirement | Cure Condition | Throughput Speed | Process Control | Thermal Window | Reliability | Best Applications |
|---|---|---|---|---|---|---|---|---|
| One-Part Heat-Cure Silicone Sealant (Dummy Product A) | Thermal activation | No | Heat (typically 80–150°C) | Fast (minutes to <1 hour depending on profile) | High (controlled by thermal profile, no mixing variability) | Stable up to 200–250°C after cure | High thermal and long-term environmental stability | Automotive electronics, mass PCB production, industrial assemblies |
Two-Part Heat-Cure Silicone Sealant
| Product | Cure Mechanism | Mixing Requirement | Cure Condition | Throughput Speed | Process Control | Depth Cure Capability | Thermal Capability | Reliability | Best Applications |
|---|---|---|---|---|---|---|---|---|---|
| Two-Part Heat-Cure Silicone Sealant (Dummy Product A) | Thermal + chemical (A/B system) | Yes (controlled ratio) | Heat-assisted curing | Very fast (minutes to <1 hour) | High (controlled stoichiometry + thermal profile) | Excellent (deep section curing capability) | Very high (stable up to 250°C+ after cure) | Very high thermal + environmental stability | EV electronics, advanced power modules, high-performance encapsulation, deep potting |
Frequently Asked Questions
Frequently Asked Questions about Silicone Sealants
What is the difference between one-part and two-part RTV silicone sealants?
One-part RTV silicones are pre-mixed and cure by reacting with ambient moisture, making them convenient to apply without any mixing step, though cure depth is limited by how far moisture can diffuse into the joint. Two-part RTV silicones separate the base and catalyst, so the moisture needed for cure is already built into the mixture, allowing for infinite depth of cure in confined or deep-section geometries, at the cost of requiring accurate mixing before application.
When is a heat-cure silicone sealant a better choice than an RTV system?
Heat-cure silicones are used when faster cure cycles or higher-throughput processing matter more than room-temperature convenience, since applying heat accelerates crosslinking substantially compared to RTV systems. They're common in high-volume manufacturing environments with the equipment to support a heat-cure step, while RTV systems remain the more practical choice for field applications, rework, or lower-volume assembly.
Why is dielectric strength important in an electronics sealant?
Dielectric strength describes how well a cured material resists electrical breakdown when exposed to voltage. In electronics applications, a sealant with strong dielectric properties helps insulate exposed conductors and connections, reducing the risk of short circuits or electrical failure when the sealant is applied near live components.
How do silicone sealants hold up under thermal cycling?
Silicone's flexible siloxane backbone allows it to expand and contract with the substrate as temperature changes, rather than cracking or delaminating the way a rigid sealant might. This makes silicone sealants a common choice for electronics that experience repeated heating and cooling cycles in service, where a rigid seal could eventually fail from accumulated thermal stress.
Do silicone sealants protect against vibration?
Yes. Silicone's inherent flexibility allows a cured joint to absorb and dampen vibration rather than transmitting stress directly into the seal or the components it protects. This is part of why silicone sealants are widely used in automotive and industrial electronics, where vibration is a constant operating condition rather than an occasional event.
Is a silicone sealant the same as a conformal coating?
No. A silicone sealant is applied to fill and seal a joint, seam, or gap, typically in a thicker bead. A conformal coating is a thin protective film, often measured in microns, applied over an entire circuit board to protect against moisture and contaminants without filling any joint. Some silicone chemistries are used for both roles, but the products are formulated differently for each function.
Learn More
Why Silicone Sealants Are Used in Electronic Applications
Silicone sealants are widely used in electronic applications to protect sensitive systems operating in harsh environments, including outdoor, industrial, and high-voltage settings. They provide a reliable barrier against moisture, dust, and environmental contaminants, making them well suited to equipment such as EV chargers, solar lighting, and communication devices.
Silicone's flexibility also allows it to absorb vibration and mechanical stress, reducing the risk of component failure in demanding installations. Cured silicone also offers strong electrical insulation and excellent resistance to thermal cycling, helping it hold up where rigid seals might crack or delaminate over time.
Together, these properties make silicone sealants a durable, reliable choice for protecting modern electronic systems throughout their service life.
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RTV System Selector Guide
Cure architecture determines processing convenience, cure depth, and throughput
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Ambient moisture
None required
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Internal moisture
Required
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Applied heat
Varies
Key Performance Considerations
Moisture & Contaminant Barrier
Forms a reliable barrier against moisture, dust, and environmental contaminants, protecting sensitive components in outdoor and industrial settings.
Vibration Absorption
Silicone's flexibility allows it to absorb vibration and mechanical stress rather than transmitting it into the joint or the components it protects.
Electrical Insulation
Strong dielectric properties help insulate exposed conductors and connections, reducing the risk of short circuits near live components.
Thermal Cycling Resistance
Remains flexible enough to expand and contract with the substrate through repeated heating and cooling, rather than cracking like a rigid seal.
Core Applications
EV Charging Equipment
Sealing outdoor charging hardware against moisture, dust, and repeated thermal cycling in exposed installations.
Solar Lighting
Protecting outdoor solar-powered fixtures and controllers from weather exposure and UV degradation.
Communication Devices
Sealing enclosures and connections on outdoor and industrial communication equipment against ingress and vibration.
High-Voltage Equipment
Insulating and sealing connections in high-voltage settings where dielectric strength and moisture resistance are critical.
Need Help Selecting the Right Silicone Sealant?
Chemistry selection depends on your joint depth, processing method, and service environment. Our technical team provides product selection support, trial quantity sourcing, and application guidance across one-part, two-part, and heat-cure silicone sealant systems.
Silicone Sealant – Quick Reference