In this guide to heat-conducting materials, we will discover their importance and what we must take into account when choosing them.

Heat-Conducting Materials: More Cost-Effective & Reliable Electronic Design

Why is heat the enemy of devices?

The reasons may vary from application to application. However, improved thermal management is becoming more critical to maintaining the long-term performance and reliability of PCB system assemblies in virtually every industry.

Transportation

From rail to the highway, vehicles are increasingly relying on PCB system assemblies for everything from optimised fuel consumption and safety to propulsion and braking. As this trend accelerates, it will drive demand for higher performance and more cost-effective thermal management solutions.

Heat Management

The trend toward smaller devices with more densely packed PCB system components is converging with the expanded use of flip-chip architectures and stacked dies. As a result, new thermal management solutions are needed to effectively dissipate heat and provide greater device reliability.

Solid State Lighting

Unlike conventional light sources, an LED module’s ability to manage temperature has a direct impact on the fixture’s reliability, output quality, lifespan and system cost. Furthermore, thermal management is becoming an increasingly important performance metric for the entire LED value chain. Solid state lighting competes with conventional lighting for high-intensity, high-temperature applications.

Power Devices

Power supplies and controls for industry, servers, and solar and wind power are handling higher electrical loads and, with them, rising temperatures. Therefore, it is necessary to improve thermal management to dissipate heat in these devices. This translates into better performance, reliability and service life. Improved thermal management also offers the necessary design flexibility.

Consumer Devices & Telecommunications

Form factor optimisation is one of the challenges facing this industry. The small size of the devices requires compact and multifunctional thermal management solutions.

Why Dow Silicone Thermal Solutions?

The inherent versatility of silicone chemistry can help expand your design freedom, increase your processing options, and improve your device’s performance and reliability. In addition, silicones generally offer advantages over organic-based urethane and epoxy solutions, including:

• Superior stability and reliability in temperatures from -45°C to 200°C.
• More physical robustness under mechanical stress is caused by thermal cycling or the mismatched coefficient of thermal expansion.
• Greater elongation and compression for extraordinary protection against shock and vibration.
• Greater hydrostability and resistance to chemical products.
• None of the toxicity problems of organics helps reduce or eliminate special handling precautions.
• Simpler processing without the need for oven drying or concerns about exotherms.
• Stable shelf life and ease of rework.

Dow builds on the inherent potential of silicone by combining it with industry-leading material knowledge, application expertise, customer collaboration and a global footprint. The value we add is even more evident in the unmatched breadth of our industry-leading product portfolio, which encompasses a wide selection of thermally conductive adhesives, compounds, encapsulants, and dispensable pads, all available in a wide range of dispensing formats. viscosities and curing chemicals and thermal and mechanical profiles.

There’s likely to be a specific category or grade that provides the optimal processing and performance benefits for your device design, and we’ve designed this guide to help you quickly narrow your search for a thermal management solution that meets your performance goals. design for heat dissipation. processability and low cost of ownership.

Latest Developments in Heat-Conducting Materials

Dow has a wide range of thermally conductive materials with different viscosities and curing chemistries, available in various formats.

Thermal Conductivity vs Viscosity

Thermal Conductivity vs Hardness

Choose Your Thermally Conductive Adhesive

DOWSIL ™ Thermally Conductive Silicone Adhesives are suitable for bonding and sealing:

• Semiconductor component hybrid circuit substrates.
• Heat spreaders.
• Applications that demand extensive design, flexible processing options, and excellent thermal management.

The high-performance thermally conductive materials in our portfolio encompass moisture-cure grades for simple processing at room temperature, as well as heat-cure solutions to accelerate productivity and time to market.

Choose Your Encapsulant, Gel or Disposable Thermal Pad

Dow’s selection of DOWSIL™ and SYLGARD™ thermally conductive silicone elastomers and gels present flexible options to protect sensitive components from harsh environmental conditions and heat. Offering low viscosity before curing, these products are easily processed and fully integrated into tall components, delicate wires and welded joints. In addition, DOWSIL ™ Thermal Pads allow you to quickly and accurately print a heat-conducting silicone compound at controllable thicknesses on complex substrates. Silicone products in this versatile wallet include:

• Encapsulants come in a variety of viscosities and cure and cure chemicals into rubbery elastomers that provide reliable protection against harsh environmental conditions.
• Gels that offer a remarkably low modulus to protect the most sensitive and delicate components against mechanical stress and the effects of thermal cycling.
• Expendable heating pads offer a versatile and cost-effective alternative to pre-made heating pads.
  

Choose Your Thermally Conductive Compound

DOWSIL™ Thermally Conductive Silicone Compounds provide high conductivity and low thermal resistance to efficiently draw heat away from sensitive PCB components and dissipate it into the ambient environment. Applied via screen or print processes or through standard dispensing equipment, our thermal compounds flow easily to completely cover and fill surface irregularities for maximum coverage. Selected grades from this product family offer thermal conductivity up to 4.3 W/mK.

Choose Your Thermally Conductive Gap Filler

DOWSIL ™ Heat-Conductive Silicone Fillers are soft, compressible solutions specifically formulated for easy processing. They prevent sagging on vertical surfaces during mounting and maintain their vertical stability after curing, even after prolonged use. These highly advanced silicone formulations dissipate heat from sensitive PCB components by efficiently conducting it to a heat sink. Able to withstand maximum exposure to 200°C, these materials perform reliably at operating temperatures up to 150°C. Our gap fillers also offer effective vibration damping.

Test Methods for Thermal Conductive Materials