hermetic seal in accordance with another embodiment of the invention the materials of the package e g lid and box are chosen to be the same so as to reduce a distortion of the hermetically sealed package as discussed heretofore in hermetically sealing a lid to a package using a soldering process it is common practice in the prior art to use an overlap joint fig1 a and fig1 b or a variation thereof the mismatch in the coefficient of thermal expansion cte of a solder material and package material s causes interfacial shear and peeling stresses at the edge of the joint after cool down to room temperature and or temperature cycling the toughness of the joining material and an interfacial adhesion is crucial in achieving a hermetically sealed device of good reliability with the slot and flange joint design of the present invention a three dimensional state of compressive stress can be achieved in at least part of the joint by appropriate material selection an important consideration for such a joint design is the coefficient of thermal expansion cte the presence of compressive stresses in the plane of the joint as well as lateral compressive stresses in the joint on top of adhesion between the various materials will improve the toughness of the joint.