One of the key reasons why most industries use adhesives over other methods of sealants is their versatility and flexibility. Adhesives can be tailored to have a number of different properties such as electrical conductivity, chemical resistance, and thermal conductivity. Thermal conductivity is a desirable property in several industrial applications for dispensing and managing of heat. However, to get the desired results, you must use the adhesives with the right properties. If you are interested to learn more about thermal conductivity adhesives, this is the right place. In this blog, we are going to discuss, the different industries that use thermally conductive adhesives, and different factors that influence the choice, and the types of formulations.

A] What Are Thermally Conductive Adhesives?

In simple terms, thermally conductive adhesives are industrial adhesives that have the capability to conduct extreme heat without degrading. These types of adhesives offer excellent heat dispensation and are generally used in heat sinks. Heat sinks are generally found in electrical devices and their job is to transfer the heat away from the electronic components. In such cases, thermally conductive adhesives play a dual role in holding the different components in place and transferring heat away from the system. The adhesive’s capability to conduct and dispense heat is largely dependent on its formulation. Hence, it is crucial to properly select or customise your thermally conductive adhesives for the desired application. Every industry and application has different requirements for thermal conductivity.

B] Which Industries Use Thermally Conductive Adhesives?

Thermal conductive adhesives are used across a vast number of industries for a number of applications. Below are some of the industries that commonly incorporate thermally conductive adhesives in day-to-day manufacturing processes.

• Electronics And PCB Industry: The growth in electronics and PCB industry has increased the requirement for thermally conductive adhesives. The electronics and PCB industry requires thermally conductive adhesives for coating and encapsulation of ICs and PCBs for heat sinking. This is crucial for the safety and proper functioning of the electronics.
• Automotive Industry: Automotive manufacturing requires a lot of electronic components to ensure the best vehicle design. Most of the electronic components in vehicles generate large amounts of heat, including the battery. Electronics thermal adhesives help to form a barrier between these electronics and the vehicle’s components and dispense heat before it reaches the engine or fuel tank.
• Aerospace And Aviation Industry: Adhesives are much lighter than mechanical fasteners, making them a prime choice for aerospace applications. Thermally conductive adhesives provide excellent bonding to electrical components that generate heat. These applications include components in satellites, aviation systems, navigation systems, and electronics.
• Medical Devices Manufacturing Industry: Conductive epoxies with thermal and electrical conductivity are widely used in the medical device manufacturing industries. Thermally conductive epoxies are used for coating, bonding, encapsulating, and potting applications in medical device manufacturing industries. As most of these devices are meant to be attached to the patient’s body, thermal management adhesives are crucial to prevent overheating.
• Industrial Manufacturing: Most industrial manufacturing process involves extreme temperatures. To ensure the adhesives used to fuse different substrates do not melt and damage the structural integrity. Using thermally conductive adhesive in lieu of standard adhesives is much more efficient and safer in these applications.

C] Factors To Consider When Choosing A Thermally Conductive Adhesive

1. Thermal Resistance

Thermal resistance is the obstruction of the free flow of heat through a material. Thermal resistance is among the first things that you should pay attention to during thermal adhesive selection. The higher the thermal resistance, the poorer be thermal conductivity, and vice versa. Thermal resistance and conductivity are both dependent on the type of material used in the adhesive and the application. When selecting a thermally conductive adhesive it is not only important to choose an adhesive with high conductivity, but also that can manage the resistance from the substrates. The size, shape, and thickness of the heatsink can all increase the thermal resistance and break down the adhesive’s capability to properly direct away heat. However, some thermal resistance is also required in order to prevent system failure.

2. Thermally Conductive Strength

This is the primary feature of the adhesive that you would want to determine before applying it to your project. Most adhesives you will find in the market will have some thermally conductive strength; however, in order to use the adhesive for the desired application, you need to determine if the conductive strength meets your requirements. As mentioned in the previous section, similar to thermal resistance, conductive strength also largely depends on the type of material used in the adhesives. Tiny particles of copper or silver are generally incorporated along with the adhesives to increase the thermal conductive strength.

3. Material Thickness 

The thickness of the heat pad directly affects the thermal conductivity of the adhesive. Thermal pads (heat pads) are used in heat sinks to redirect the heat; however, if the material is too thick, it will negatively affect the heat transferability. In a thicker heat pad, the heat transfer path is increased reducing heat transfer efficiency and increasing the resistance. It is always best to select a thinner heat pad to maximise heat transfer efficiency. However, in certain applications that is not feasible, so in such cases, the density and conductivity of the materials are to be altered to fit the requirement.

4. Adhesive Compatibility With The Substrate

Substrates can greatly affect the mechanical and chemical properties of an adhesive. Regardless of the other factors like conductivity, resistance, and material thickness, if the adhesive is not compatible with the substrate, the bond will fail. When choosing the conductive adhesives, factor in the substrate and application to select the right kind of adhesive. Certain substrates pair well with certain adhesives and can offer higher bond strength, reliability, and longevity. These adhesives can be tailored and modified to have better thermal properties to suit your industrial needs.

5. Availability And Cost

Availability and cost might not seem like the first thing to look for when selecting an adhesive. But if the adhesive can not be manufactured or is not available to you at the moment, all the planning is not fruitful. Other times, even if you find the adhesive, it is very costly. Hence, sometimes the best thing to do is go for an alternative. Contrarily, you can contact a reputed adhesive manufacturer in India to get tailored thermally conductive adhesive that fits all your application requirements and your budget. An adhesive manufacturer will be able to guide you through the different types of thermally conductive bonding solutions that suit your needs.

Conclusion

Selecting the right thermally conductive adhesives for your industrial application is a big decision. There are several factors that you must consider before finalising the adhesive. The adhesive’s conductivity strength, bond strength, compatibility with the substrates, availability, and cost are all factors that influence your choice of adhesive. If you are looking for a thermally conductive adhesive with specific thermal and mechanical properties, it is best to get it custom-made. Kohesi Bond is a manufacturer and distributor of high-quality, bespoke thermal adhesives with various mechanical and chemical properties for your industry needs. Contact us today for a detailed discussion!