| 摘要 |
PURPOSE:To provide an electronic part or a circuit board having a metal thin film layer for solder connection which ensures good connection and high reliability even after many times of repair and also realize an electronic circuit device utilizing these electronic part or circuit board and a method of manufacturing the same electronic circuit device. CONSTITUTION:A metal layer 20 for solder connection to be formed on a circuit board 6 is formed of a metal layer consisting of Ni-W alloy metal, for example, allowing coexistence as the constituting elements of a first metal such as Ni, for example, which is easily wettable with a metal 3, 4 forming a solder and can easily form an alloy or an intermetal compound and a second metal 2 such as W, for example, which does not easily wet and is not melted away. In this case, it is also possible to form concentration gradient within the metal layer so that concentration of the first metal becomes high in the side of connecting surface and thereby wettability of the solder can be much improved. |
