What Does a Gap Filler Do?

Gap fillers work by filling in air gaps with a thermally conductive material, preventing the air from acting as an insulator around heat-generating components. The gaps filled by these materials can range from microscopic (as small as 0.001" or 0.25mm) to as large as 0.400" or 10mm and greater.

Gap filler materials can be either selectively placed or used to cover multiple heat sources within a single application, and they can be used at varying heights to displace air and provide effective cooling. They are designed to enhance thermal performance and fit seamlessly into high-volume manufacturing operations.

Thermal gap fillers are used on many electronics devices across a wide range of industries. They are often applied onto printed circuit board (PCBs), battery modules, power electronics, and other heat-generating components. 

Within automotive electronics, gap fillers are used on engine control units (ECUs), advanced drive assistance systems (ADAS) modules, and battery management systems (BMSs) to improve thermal performance and ensure long-term reliability. 

Additionally, gap fillers can be used in smart phones and tablets, game systems, smart home devices, internet infrastructure, satellites, drones, telecommunications equipment, defense electronics, avionics systems, alternative energy devices, and many other applications.

Gap fillers primarily come in a dispensable pad or gel form and fill in gaps caused by assembly or manufacturing tolerance.

Thermal gap pads are designed to be soft, reduce component stress, and provide vibration dampening. They cover a range of thermal conductivity values with higher conductivity associated with greater heat dissipation.

Gap pads provide a lot of manufacturing flexibility and can be easily designed to fit an application’s unique specifications. Pads come in sheets or continuous rolls at various thicknesses, and they can be cut to accommodate most sizes and thermal performance needs.

Thermal gels are a one-component material that requires no curing processes, meaning they will immediately provide heat transfer characteristics once applied. Other types of TIMs may require the material to undergo an additional cure process which can last hours or even days, adding time and complexity onto the manufacturing process.

Thermal gels also simplify the supply chain by allowing manufacturers to use one product to meet an application’s thermal requirements. Instead of using multiple sizes and thicknesses of gap pads which can mean changing parts or modifying engineering requirements, users can dispense varying amounts of thermal gels to fill the required space.

Thermal pads and thermal gels are two excellent options to fill gaps and enhance thermal performance. Our customers often ask, what is the best thermal interface material? It’s important to note that there is no one-size-fits-all approach to gap fillers because the best fit will be the one that fits your application’s specific needs. If you need help working through the options, please reach out. Our experienced engineers are available to help you find the right solution.