Radio-Frequency Characterization of Thermally and Electrically Conductive Adhesives for Antenna Applications

The RF behavior of Thermally and Electrically Conductive Adhesive (TECA) material has been investigated for high-frequency applications through measurements that are documented in this paper. TECA materials are typically used to provide conductive bonding between substrate layers in high volume planar designs like antenna arrays. This study compared the performance of a copper microstrip transmission line with a TECA material, called COOLSPAN, which is a conductive epoxy based silver filled adhesive film. The adhesive was laminated onto the substrate to function as the conducting signal trace in a microstrip line configuration and was compared to a more typical copper trace. The S-Parameter measurements for the two transmission lines closely agreed below 9 GHz. Therefore, the use of thermally and electrically conductive adhesives can be used in multi-layer, substrate integrated antenna designs for the lower GHz ranges. This will greatly simply the fabrication process providing a reliable conductive pathway, while also enabling thermal management within the entire RF module.