IGBT device is developed from silicon to wide bandgap semiconductor materials, and its working temperature has reached to 300 °C, so the encapsulation is particularly important. NanoCu paste is investigated under H2 at 300°C. A chip is linked to DBC substrate by nanoCu paste under air with different temperature. Results shows the increase of sintered time temperature effectively reduce the porosity of sintered layer and enhance the strength.@en