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Cova Scientific By Cova Scientific • September 7, 2015

Thermally Conductive Epoxy Selection Tips




Due to the fragmented nature of the specialty adhesive formualtor market, researching and selecting a thermally conductive epoxy (or any specialized polymer adhesive) has historically not been the easiest process. Engineers who are seeking to meet specific application requirements either have to settle for a commodity product, or struggle to review more customized/ specialized polymer products from a handfull of specialty formulators who struggle to make themselves accessible online.

 At Cova Scientific we're dedicated to bridging the gap between engineers and specialty adhesive knowledge. Here are a few useful tips to help you make your thermally conductive epoxy selection. These tips by no means will help you answer all the questions you'll encounter in your research/ selection process, but they're certainly a great place to get started.

1: Determine if you application requires an electrically insulating thermally conductive epoxy

Most applications CAN NOT tolerate an electrically conductive polymer in a thermally conductive application, but this point is worth mentioning nonetheless. Some electrically conductive filler materials (such as silver) offer exceptionally high thermal conductivity, higher than electrically insulating alternatives (such as alumina). If your application can tolerate an electrically conductive epoxy material, determining this at an early stage allows you to potentially open the door to a whole group of exceptionally high thermaly conductivity materials.

2: Decide if viscosity or thermal conductivity is more important

Although this isn't always the case, high thermal conductivity and high viscosity generally come hand-in-hand.  Higher thermal conductivity requires higher levels of the filler material by weight. Higher filler levels inevitably leads to higher viscosity. Depending on your application and assembly requirement, viscosity may or may not be important. However, deciding your priority early in the selection process will allow you to limit your search and be more decisive in your process. 

**note - if viscosity and thermal conductivity are BOTH priorities, contact us. Solutions do exist and one of our partner companies will be able to design a custom system for your applicaiton.

3: One-part vs. two-part thermally conductive epoxies

Depending on the size of your project, mixing may become a major issue. Thermally conductive filler materials are generally abrassive and, as just discussed, raise the viscosity of the uncured system. This means high stress on mixing equipment, which in turn translates to shorter equipment life. For large scale projects, a single component system may be the intellegent choice. One component systems will require heat in order to finish the reaction, but won't require mixing like two-part alternatives.