Thermal adhesive
Thermally conductive adhesives are two-component adhesives , mostly on an epoxy or silicone basis, which are used, for example, to assemble heat sinks . The thermal conductivity is created using ceramic or metallic fillers (Al 2 O 3 , AlN). Compared with thermal paste is the specific heat conductivity generally lower. In addition, there is the usually required greater layer thickness. For the "non-destructive" dismantling of bonded components (cooler, components ...), however, the bonded connection usually has to be weakened beforehand (e.g. by heating above the glass softening point T G ).
There are several aspects to consider when choosing the right adhesive. An increased filler content improves the thermal conductivity, but worsens the strength of the adhesive connection. If the adhesive content is too high, this can lead to significant expansion differences (CTE mismatch) and loosen the adhesive bond, since organic substances have a very high expansion coefficient compared to inorganic materials. Thermally conductive adhesives based on epoxy resin have better thermal conductivity than silicones due to the denser crosslinking. If, however, mechanical tensions must also be compensated for using the adhesive, then the silicone material class is more advantageous, as is the case with conventional adhesive technology.
Individual evidence
- ↑ Technical data sheet: Thermally conductive adhesive WLK Two-component adhesive based on epoxy. Retrieved September 25, 2014 .