Microrobot-based nanoindentation of an epoxy-based electrically conductive adhesive

Microrobot-based nanoindentation is a relatively new testing technique, which uses microrobot based methods for performing nanoindentation experiments. The use of the microrobot-based nanoindentation is a example how microrobotic technology can help the materials research. In this work, the hardness of an epoxy-based silver-filled electrically conductive adhesive (ECA) type PC 3002 has been determined using this method. Flat ECA specimens have been investigated after a first curing at 70degC for 120 minutes, respectively after a curing time of 150 minutes, 180 minutes, 240 minutes, 300 minutes, and finally after 325 minutes at the same temperature. The maximum indentation depth was 1 mum. The hardness of the ECA has shown an increase with the increase of the curing time at constant temperature. The set-up uses a Berkovich diamond tip for performing nanoindentation tests. The set-up requires calibrations with reference specimens (fused silica and sapphire) for calculating hardness and Young's modulus of the tested material. Preliminary results are very promising: by comparing the slope of the loading stage of the nanoindentation tests on different specimens, the difference in hardness can be qualitatively evidenced.