The increasing power of electronic devices and the drive towards miniaturisation make heat dissipation a crucial aspect of design. Thermal management is no longer just a matter of efficiency, but a necessary condition for ensuring safety, reliability and operational continuity.
This article provides a comprehensive overview of Dowsil technical solutions, analysing materials, mechanisms and application benefits for heat dissipation in complex electronic systems.
Why heat dissipation is essential in electronic components
During operation, every electronic component generates heat as a by-product. When not dissipated efficiently, this accumulation leads to a rise in temperature to the point of equilibrium. According to Newton’s law of cooling, the rate of heat loss depends on the temperature difference between the component and the environment: if this difference is insufficient or the exchange surface is reduced, there is a risk of performance degradation, malfunction or irreversible failure.
This is why heat dissipation must be planned at the design stage. High power density devices, such as LEDs, inverters, IGBTs or microprocessors, require materials and systems that act as an efficient interface between the source and the heat sink.
Solutions and materials for heat dissipation
The first level of thermal management is often entrusted to passive heat sinks, which increase the surface area available for heat transfer to the environment. However, the contact surfaces between the component and the heat sink are never perfectly smooth: metallic roughness creates micro-air spaces, which are insulating by nature and compromise the efficiency of the system.
To solve this problem, thermal interface materials (TIMs), such as thermal pastes, adhesives or pads, are used to fill the micro-cavities, improve thermal contact and reduce thermal interface resistance.
Thermal pastes: the heart of effective heat dissipation
Silicone and non-silicone formulations
Dowsil thermally conductive pastes are composed of thermally conductive fillers suspended in a non-curing carrier fluid. This makes them ideal for applications where reworkability is required, or where the geometry does not allow the use of rigid materials.
Dowsil offers:
- Silicone pastes: low viscosity, resistance up to 200°C. Useful where high temperature stability is a priority.
Non-silicone pastes: necessary in contexts where volatile siloxanes can compromise adhesion, cleanliness or insulation (e.g. optics, sensitive circuits, coatings)
Encapsulating resins: protection and integrated thermal management
- In harsh industrial environments, electronics must withstand humidity, dust, vibration and corrosive conditions. Encapsulation resins offer a 2-in-1 solution to these problems: protection and thermal dissipation.For some types of circuits, it may be advantageous to encapsulate the device in a heat sink enclosure using a thermally conductive compound.Dowsil manufactures a range of two-part encapsulation solutions using epoxy, polyurethane and silicone technologies:
- Epoxy: maximum insulation and conductivity up to 1.54 W/m·K.
- Polyurethane: elasticity and resistance in tropical or marine environments.
Silicone: operation over an extended range (-60/+200°C), perfect for selective potting or environments with large temperature fluctuations.
Typical properties of heat dissipation products
- Heat dissipation materials are chosen not only for their performance in the laboratory, but also for their ability to maintain efficiency and stability over time, even under extreme operating conditions. The key properties to be evaluated are:
Thermal conductivity
- This is a measure of a material’s ability to transfer heat, expressed in W/m·K. Mass conductivity values provide an indication of the expected transfer, but for a realistic assessment it is also essential to consider the thermal resistance of the interface, which takes into account the thickness applied, the quality of the contact and the pressure exerted. A highly conductive paste, if applied in too thick a layer, may be less efficient than one with lower values but applied correctly.
Operating temperature range
- Environmental conditions can vary greatly depending on the application, which is why our Dowsil products offer materials with extended temperature ranges, from -60°C to +230°C. It is important to select products that maintain integrity and thermal performance even during off-specification excursions or repeated thermal cycles.
Dielectric strength
- In electronic systems, it is crucial that the materials used for heat dissipation do not compromise electrical insulation. Heat dissipation products offer excellent dielectric strength values, with peaks of up to 42 kV/mm for non-silicone pastes and excellent performance even on resins and RTVs.
Viscosity
- Viscosity affects the method and quality of application. Thermal pastes must be fluid enough to form a thin layer but stable enough not to suffer from pump-out over time. Gap fillers have very high viscosities to ensure resistance to vibration and deformation. Once applied, resins and RTVs polymerise and become mechanically stable; in this case, viscosity is important for dispensing, not for final performance.
Thermal management applications
- Photovoltaic inverters: known for their sensitivity to temperature and subject to continuous thermal stress.
- Connections between heat pipes and water tanks: in solar heating applications.
- Hydrogen fuel cells: where heat dissipation ensures electrochemical efficiency and durability.
- Wind generators: in environments exposed to temperature changes, vibrations and humidity.
- LEDs and lighting: to maintain constant luminous flux and extend service life.
- Miniaturised electronics and embedded systems, where reduced volume amplifies the risk of overheating.
Conclusion
Heat dissipation is now a technical discipline in its own right. The solutions offered by Dowsil, a partner of MD Poland, cover all thermal management needs.
Choosing the right material means optimising the performance, safety and durability of your electronic system.
Contact the experts at MD Poland for qualified technical support in selecting the most suitable solution for your project. Our experience is at your disposal for all your heat dissipation needs in the industrial, e-mobility, LED, power electronics and green energy sectors.
