You may know about thermal pads and thermal tape when choosing a thermal interface material, but are struggling to make the right choice. This article will detail the differences between these two materials in terms of raw materials, properties and usage.
What are Thermal Pads?
Thermal pads are pre-moulded thermal interface materials that fill the space between the element and the heat sink. It helps dissipate heat by replacing the air between the heating element and the heat sink, increasing the contact area and reducing thermal resistance. It usually has a very high thermal conductivity and is made to have different thermal conductivities depending on the material.
What are Thermal Tapes?
Thermal tapes are primarily used to bond two components while providing thermal conductivity as a thermal interface material. It solves the problem of component fixing without the use of screws and nails, so it is very easy to install and suitable for direct bonding to various surfaces. It enhances the mechanical strength of your products while providing thermal conductivity to prevent equipment overheating and loss of control.
Thermal Pad vs Thermal Tape: Comparison of Materials
Materials of Thermal Pad
Common thermal pads are made of silicone with added high thermal conductivity materials, graphite flakes, phase change materials and ceramics. Different thermal pads made of different materials have different characteristics (e.g., thermal conductivity, temperature range, cost). You can choose them according to your usage needs. In addition, unlike thermally conductive tapes, the adhesive layer of thermally conductive pads is added at your own choice.
Materials of Thermal Tape
Thermally conductive adhesive tapes are usually double-sided, and their structure consists of a base material layer and two adhesive layers. To prevent the tape from sticking and failing before use, it is covered by a protective lining. You can easily peel it off when in use. The base material layer of the thermally conductive tape is made of PET or glass fibre cloth with the addition of thermally conductive ceramic particles. The main material for its adhesive is acrylic.
Thermal Pad vs Thermal Tape: Comparison of the Properties
Comparison of Thermal Conductivity
Different models of thermal pads and thermal tapes have different coefficients of thermal conductivity. Overall, thermal pads have a higher thermal conductivity than thermal tapes, providing higher thermal performance. Thermal tapes provide thermal conductivity of around 0.5 to 5 W/m.K, while ultra-high-performance thermal pads can even reach an excellent thermal conductivity of 90 W/m.K.
Comparison of Operating Temperatures
Thermally conductive gaskets and tapes can withstand harsh temperatures and ensure stable performance. Thermally conductive gaskets can be used at temperatures ranging from -60 to 200°C, while thermally conductive adhesive tapes can be used at temperatures ranging from -40 to 120°C. In comparison, thermally conductive gaskets are more resistant to high and low temperatures, but they are both UL94-VO fire rated. So you can use them safely at the recommended temperatures.
Comparison of Adhesive Strength
Thermal tape is a strong adhesive material. It provides a strong bonding strength to a variety of surfaces without the need for additional tools such as screws and nails. Thermal pads have an adhesive in their rubber composition, but not a strong adhesive. Only enough to make it better at filling flat depressions. However, if you have the need, you can choose the thermal conductive spacer with an adhesive layer to provide you with stronger bonding ability. But it may affect its thermal conductivity.
Comparison of Application Difficulty
Thermal tapes and thermal shims are soft and solid materials. They do not need to be applied to the surface as evenly as thermal paste. Their extremely high degree of compliance allows them to easily adhere to surfaces and compress to very thin thicknesses with little pressure. When in use, you can easily cut them into a variety of sizes, thicknesses and shapes to suit different surface needs.
Comparison of Service Life
Thermal pads and tapes are designed to last for a long time without failing due to strict quality control. However, they may deteriorate in performance over time and you will need to replace it. Thermal pads can last from 3 to 7 years, and ultra-high-performance pads may last longer. Thermal tape, on the other hand, lasts about 2 to 5 years, which is shorter than thermal pads. In addition, improper use, such as outside the temperature range, can significantly shorten the life of both the thermal pad and the thermal tape.
Comparison of Reusability
Once the thermal tape is applied, you will not remove it easily. Removal can also cause residue or even damage to the components. And the adhesive layer of the used tape is destroyed and cannot be reused. Thermal pads without an adhesive layer offer long-lasting performance stability and can be reused unless they experience physical damage. However, it is recommended that you replace old thermal pads promptly for optimal heat dissipation.
Comparison of Cost
Thermal pads cost more than thermal tapes due to the difference in raw materials. Ultra-high-performance thermal shims will cost you more while giving you superior performance. However, thermal pads have a longer service life and can be reused, making them a cost-effective option.
Thermal Pad vs Thermal Tape: Comparison of Application
Application of Thermal Pads
For ease of application, thermal pads can be processed into sheets, die-cut/kiss-cut parts or pre-laminated boards with adhesive, DC1 (one-sided adhesive), etc. You can use them in battery modules for electric vehicles, high-power LED lights, power supply modules, telecommunication equipment, radar, CNC laser equipment, and more. Thermal pads provide stable heat dissipation, maintain normal operation and extend the life of your equipment.
Similar thermal‑design concerns come up for decorative lighting builds such as LED‑backlit blue onyx wall systems, which use dense LED arrays behind translucent stone panels.
Application of Thermal Tape
Thermally conductive tapes are often processed into sheets, die-cut/kiss-cut parts or rolls for ease of use. Commonly used for mounting components such as mounting heat sinks, mounting LED lights, mounting transistors, installing thermoelectric cooling modules, etc. It not only provides a strong connection but also provides some heat dissipation for your device.
How to Choose Between Thermal Pads and Thermal Tapes
Choose According to the Function
If thermal conductivity is the most important thing in your selection, then thermal pads are a better choice. It offers a wide range of thermal conductivity options to meet the needs of your different power devices, and it stays in use for a long time. If you need stronger adhesive properties, thermal tape is more suitable for you. It can achieve an excellent fixing effect without screws.
Choose According to Your Product
If you are using the thermal interface material to fill a large gap or have a very uneven surface, choose a thicker thermal pad to minimise thermal resistance and improve thermal conductivity. For portable devices with high weight requirements, choose a lighter weight thermal tape. For devices that are subjected to vibration and shock during operation (such as those in automobiles), choose a thermally conductive tape to make your product more reliable.
Choose According to Your Budget
Thermal tape is a less expensive option. However, if your product has high durability, you should choose thermal pads that last longer. Both thermal pads and thermal tapes are easy to install and you can use them for high volume automation. You can make the optimal choice based on performance and budget.
Conclusion
Understanding this article can help you make a better choice. Whether it’s thermal pads or thermal tape, GALLOP INNOTEK has the proven experience and professional team to provide you with high quality solutions. We hope to be your trustworthy partner, please feel free to contract us!
