wo-Component Silicones and Thermally Conductive Solutions for Electronics
Two-component silicones, or 2K silicones, cure after two components are mixed together. Their curing mechanism does not rely solely on atmospheric moisture, making them particularly suitable for industrial processes requiring repeatability, controlled dispensing or automated application.
Samaro distributes DOWSIL™ and SYLGARD™ solutions from Dow for electronic potting, dielectric protection and thermal management.
Different functions should however be distinguished: thermally conductive encapsulants, thermally conductive adhesives, gap fillers and thermal interface compounds are designed to address different requirements.
What is a thermally conductive adhesive?
A thermally conductive adhesive is designed to provide both mechanical bonding and heat transfer between two surfaces, for example between an electronic component and a heat sink, housing or another part of the thermal path.
Unlike a non-curing thermal paste or compound, a thermally conductive adhesive cures to form a bond between the parts.
Depending on the application, this can reduce or eliminate the need for certain mechanical fastening systems.
Thermal conductivity expressed in W/m·K is an important parameter, but it should not be considered in isolation. Bond-line thickness, geometry, contact surfaces, dielectric requirements and dispensing conditions also influence the performance of the complete assembly.
Which thermally conductive solutions are used in electronics?
Silicone technologies can perform several different thermal management and protection functions.
Thermally conductive potting and encapsulation
Thermally conductive potting consists of partially or completely filling an electronic housing with a material that provides both environmental protection and heat transfer.
It can be used in power modules, converters, on-board chargers and control units where heat generated by the components needs to be transferred towards the housing or another heat-dissipating surface.
Among the solutions available from Samaro:
- DOWSIL™ TC-6015 is a two-component thermally conductive silicone encapsulant. See Part A and Part B.
- DOWSIL™ TC-6020 is a low-viscosity two-component thermally conductive silicone encapsulant for electronic potting applications. See Part A and Part B.
Selection depends on parameters including required thermal conductivity, viscosity, geometry and curing conditions.
Thermally conductive gap fillers
A gap filler is designed to fill the space between a component and a heat-dissipating surface, improving thermal contact while accommodating dimensional tolerances within the assembly.
DOWSIL™ TC-4530 CV is a two-component thermally conductive silicone gap filler developed for electronic thermal management applications.
Its rheology also makes it suitable for automated dispensing processes.
Thermal interface compounds
Not every thermally conductive material is a two-component system.
DOWSIL™ TC-5026 Thermally Conductive Compound is a single-component silicone thermal compound designed to transfer heat away from electronic equipment.
Unlike a thermally conductive adhesive, its primary function is thermal transfer at the interface rather than structural bonding.
Electronic potting and dielectric protection
Two-component silicones can also be selected when the main objective is electrical and environmental protection.
SYLGARD™ 184 is a transparent two-component silicone used for potting and protecting electronic components, sensors and assemblies.
In this type of application, selection should be based on electrical, mechanical, optical and processing requirements rather than on thermal conductivity alone.
How do you choose a thermally conductive material?
Material selection should start with the function the product needs to perform within the assembly.
1. Define the interface function
Does the material need to bond two parts, fill a gap, encapsulate a volume or simply improve thermal contact? This first step helps distinguish between an adhesive, encapsulant, gap filler and thermal compound.
2. Define the thermal requirement
Thermal conductivity is important, but the complete thermal path should be considered, including contact surfaces, material thickness, heat generation and the acceptable component temperature.
3. Match viscosity to the process
Filling a complex housing, dispensing through automated equipment and creating a thin thermal interface require different rheological properties.
4. Consider mechanical requirements
Hardness, flexibility and the ability to accommodate differential thermal expansion may become important when components are exposed to vibration or repeated thermal cycling.
5. Integrate the curing process
Mix ratio, working time, curing speed, possible heat acceleration and production rate must all be compatible with the manufacturing process.
6. Check electrical and regulatory requirements
Dielectric properties, electrical insulation, flammability requirements and other specifications should be checked for the exact product grade according to the application requirements.
Solutions available from Samaro
DOWSIL™ TC-6015
Two-component thermally conductive silicone encapsulant for the protection and thermal management of electronic modules.
DOWSIL™ TC-6020
Low-viscosity two-component thermally conductive silicone encapsulant designed for applications requiring effective filling of electronic housings.
DOWSIL™ TC-4530 CV
Two-component thermally conductive silicone gap filler designed to fill interfaces between electronic components and heat-dissipating surfaces.
DOWSIL™ TC-5026
Single-component thermally conductive compound for thermal interfaces in electronic equipment.
SYLGARD™ 184
Transparent two-component silicone for electronic potting and component protection.
Other electronic protection technologies
Electrolube and MG Chemicals complement Samaro’s portfolio with materials for electronic protection, potting and thermal management.
For a broader view of these technologies, explore Samaro’s Electric & Electronic Protection & Assembly solutions.
Our technical team can help qualify your thermal requirements, dispensing process and electrical and mechanical constraints in order to identify a solution suited to your application.