Adhesive Bonding vs. Soldering of Power Modules Using Polytec’s New EC 242 Conductive Silver Adhesive
Adhesive bonding of power modules can often be an alternative to usual joining techniques. This has been revealed by a recent research project performed by the IMTEK Department of Microsystems Engineering and the IESY Institute of Electric Power Systems at the University of Freiburg and Magdeburg, resp. According to the results, Polytec’s EC 112 conductive silver adhesive has shown good mechanical and electrical performance, including high die shear strength between 25 and 30 MPa, stable over 2500 temperature cycles. In the meantime, Polytec has developed an even better silver adhesive, EC 242, showing superior thermal conductivity of above 4 W/mK as well as extremely low electrical resistivity of about 5 * 10-5 Ohm cm. Both features are critical for the thermal management of power chips. EC 242 can withstand continuous operation temperatures up to 230 °C and has a glass transition about 110 °C. The photo shows a power module assembly using an IGBT and a diode attached onto a DCB substrate by using EC 242 adhesive (photo courtesy of IMTEK).