Silver micropowders as SiC die attach material for high temperature applications

This work is devoted attaching technology between SiC structures and DBC substrates for creating SiC devices able to work at temperature up to 350°C. Our current work was concentrated on finding so called “pressure sintering” procedure in air using Ag micro particles. A special test samples with a size corresponding to the dimension of the SiC structures were assembled to DBC substrates with different surface finishing by Ag micro powder sintering. In the first series of experiments DBC substrates with Cu electroplated by Ni (3÷5 μm) and Au (above 1 μm) were used. It was found that by modifying application procedure of Ag micro powder onto DBC substrate with Cu/Ni/Au metallization, it is possible to obtain good adhesion between attached samples. The sintering is performed in air at temperature of 400°C for 40 min and pressure of 10 MPa. In the second series of experiments the SiC structures with Ni/Au metallization were assembled to DBC substrate with Cu/Ni/Au metallization. The adhesion higher than 10 MPa was obtained for such prepared samples.