Thermal Interface Materials: Frequently Asked Questions (FAQ)
Thermal interface materials (TIMs) are used between two or more substrates to allow efficient thermal dissipation and protection.
The global thermal interface materials market was valued at £2.9 billion in 2022, estimated to grow by a rate of 11.4% by 2030. This growth is accounted for by the proliferation of electronics within society, such as electric vehicles, electric bikes, electric aircraft, smart cities and smart technology. The growth within this industry is pushing manufacturers to invest in more innovative thermal interface materials, gaining a competitive edge and reducing costs while improving equipment functionality and quality.
Here we answer the top frequently asked questions on thermal interface materials:
How Do Thermal Interface Materials Work?
Thermal interface materials work by filling in the air gaps between a heat-producing component and a heat-dissipating component.
These air gaps naturally exist between components as it’s unlikely that their surfaces match up perfectly at the microscopic level. As a result, only a fraction of the heat produced can be effectively transferred to the heat-dissipating component, leading to the heat escaping to other parts of the assembly. This can lead to overheating, component damage, and premature equipment failure.
Thermal interface materials replace these air gaps with a thermally conductive material that facilitates efficient heat transfer between the two components.
What Are the Advantages of Thermal Interface Materials?
Thermal interface materials provide many advantages to heat-producing assemblies, ranging from:
- Reducing assembly size by eliminating the need for larger heat sinks, fans or cooling equipment.
- Improved safety due to reduced chances of overheating and fires.
- Increased efficiency of electronic components due to lack of overheating.
- Reduced chances of premature component failure and therefore equipment breakdown.
- Reduced requirement for repair and maintenance – reducing costs.
- Higher component durability and reliability.
- Faster equipment assembly due to the potential for automation.
It’s important to note that the advantages of thermal interface materials are best demonstrated when they are used early in the design and manufacturing process.
Where Are Thermal Interface Materials Used?
Thermal interface materials are commonly used across various industries that require heat dissipation, with applications ranging from:
- Renewable energy power electronics
- Consumer electronics
Thermal interface materials are used directly between a heat-generating component and a heat-dissipating substrate, facilitating efficient heat transfer.
What Are the Different Types of Thermal Interface Materials?
The main different types of thermal interface materials range from:
- Gap fillers: can fill gaps up to 15mm; high thermal conductivity; come in gel, pad or putty formats.
- Phase change materials: provide low thermal impedance; solid state at room temperature, allowing workability, then soften or liquify under heat to easily fill voids on surfaces.
- Thermal tapes: double-sided adhesive tapes; eliminate the need for mechanical attachments; used to attach small heatsinks to components.
- Greases: can fill gaps up to 5mm (good for thin surface gaps); easily dispensible with no cure cycle.
- Curable compounds: used for gap filling, potting, sealing, and encapsulating for any size or shape; high thermal conductivity; cures in place.
Are Thermal Interface Materials Electrically Insulating?
Certain thermal interface materials can be electrically insulating, but not all are.
As a general rule, TIMs that exhibit a breakdown voltage on their data sheets are capable of providing electrical insulation.
As TIMs that possess electric insulation can be more costly, it’s suggested to only use them when they are absolutely necessary.
How Do I Choose a Thermal Interface Material For My Application?
Factors to consider when choosing a thermal interface material include:
- The temperature range in which the component will operate – e.g. silicone-based TIMs can withstand higher temperatures than non-silicone alternatives.
- The distance between the heat source and the heat-dissipating substrate.
- Whether electrical insulation is required.
- Compressibility of the TMI – particularly important for irregular surfaces.
- The thermal impedance required – measures the efficiency and rate of heat transfer. Thicker TIMs typically have lower thermal impedance.
- The thermal conductivity required – measures the material’s ability to transfer heat.
- The requirement for UL 94 flame class rating.
- Surface flatness of the substrates used.
The specifications of the application at hand must match as closely as possible to the characteristics provided by the choice of TIM, in order to achieve the maximised intended function.
What Range of Thermal Interface Materials Does Antala Offer?
Manufacturers can use our selection guide on thermally conductive materials to find the most suitable heat dissipation solution for their application.
For detailed advice, get in contact with us directly to determine the most suitable solution for your inquiry.