Thermal conduction in novel isotropic conductive adhesive

A novel and low silver content isotropic conductive adhesive (ICA) has been developed and characterised. The conductive particles are based on a silver coated polymer sphere. The thermal properties of the ICAs have been investigated by two different characterisation techniques based on a steady state method and a contactless transient method. Results show that the thermal conductivity is strongly correlated with both volume fraction and silver coating thickness of conductive particles. A thermal conductivity (κ) of more than 2.8 W/mK has been obtained for an adhesive containing less than 4% volume of silver. However, a significant difference between the results obtained using the steady state and transient methods has been observed above the percolation threshold. One possible reason for this is the different volumetric constraints during the sample preparation.