| 摘要 |
PROBLEM TO BE SOLVED: To provide a cover for a package for storing therein electronic components and to provide an electronic device using the cover wherein the airtightness and the reliability of the cover can be maintained even though a temperature of 250-260°C is applied to it when mounting it on an external circuit, etc., it contaminates no earth-environment since it contains no lead, and further, the scope of its heating and joining temperature condition is so wide as to improve its productivity. SOLUTION: The cover 4 has a metal layer 2 made of a nickel-cobalt alloy and formed over the whole of the outer periphery of the rear surface of a plate-form body 1, and has a solder layer 3 containing tin as its main component and formed on the front surface of the metal layer 2. Further, the cobalt concentration of the metal layer 2 which is present on the side of the interface between it and the plate-form body 1 is lower than the one present on the side of its front surface. Moreover, the nickel concentration of the solder layer 3 which is present on the side of its front surface is lower than the one present on he side of interface between it and the metal layer 2. COPYRIGHT: (C)2006,JPO&NCIPI |
