A method of assembling semiconductor devices includes applying a metal paste including a plurality of metal particles having an average size less than 50 nanometers and a binder material onto a metal terminal of a package substrate. The metal paste is processed including a heat up step in a reducing gas atmosphere and then a vacuum sintering step at a temperature of at least 200° C. for forming a sintered metal coating. A semiconductor die is attached onto a die attach area of the package substrate. A bond wire is then connected between a bond pad on the semiconductor die and the sintered metal coating on the metal terminal.