Abstract: An apparatus and process for iso-thermally sealing electronic packages with a thermosetting adhesive have first and second platens for holding and for heating a package and a lid, respectively. The second platen is operatively coupled to the first platen, so that alignment of the package to the lid is automatically achieved when the first platen and the second platen are placed in a sealing position. The process includes the steps of pre-heating a package and a lid, the lid having a mating surface coated with a thermosetting adhesive; and mating together the heated package and the heated lid when iso-thermal conditions are achieved. The iso-thermal seal process and apparatus are based on the principle of uniting the package and the lid with a thermosetting adhesive after all three components, and gases in the cavity as well, are already at a stable adhesive curing temperature.