Wirebonding has been performed successfully up to 200 C with no die swimming. Wirebond pull strengths are equal to those of dice attached with thermoset adhesives. Twenty dice from one lot were assembled into 28-pin sidebrazed packages. Ten of the dice were attached with thermoset adhesive, and the other ten were attached with thermoplastic preforms. Table 2 shows the results.
Further testing is planned.
The wafer can then be diced and stocked with the adhesive in place. This eliminates the need for preform placement at assembly. Table 3 lists initial parameters used. Thicker depositions need to be achieved, but good results were obtained in regards to the adhesion of the thermoplastic to the wafer. Another application is the development of a preform that can be used for end-terminated capacitors.