| 摘要 |
PURPOSE:To make it possible to obtain a high-reliability ceramic package by a method wherein after the platings of two layers of a cobalt-plated layer and a nickel-plated layer are applied in order as a base metal layer, a metal layer subjected to annealing treatment is provided. CONSTITUTION:A metal layer which is provided on a ceramic substrate is formed in such a way that it is a metal layer formed by performing an annealing treatment on a two-layer plating obtainable by forming a nickel-plated layer on the upper layer of a cobalt-plated layer. In case the two-layer plating is provided, a cobalt plating is first applied on a metallized layer formed on a ceramic substrate, then, a nickel plating is applied. Accordingly, tungsten which is a metallized metal stops dissolving by a potential difference between the metallized metal and the plated metal and when the two-layer base plating is subjected to annealing treatment, cobalt is diffused in the nickel-plated layer. Therefore, a reduction in a die bondability due to a heating treatment and the like and the generation of a defective due to rust in a moistening condition and the like are eliminated. Thereby, a high-reliability ceramic package can be obtained. |
