| 摘要 |
PROBLEM TO BE SOLVED: To prevent the deterioration of a filter characteristic by means of heat at the time of reflow soldering by permitting the film thickness of a nickel layer in an inductor electrode formed on a print substrate to be equal to lower than a specified value. SOLUTION: The inductor electrode 2c is formed on the print substrate 2 and is provided with a nickel layer and metal on a copper layer and the film thickness of the nickel layer is less than 2μm (zeroμm excluded). The lower limit of the film thickness of the nickel layer can be any value if a gold plating layer is formed on the copper layer. But gold plating is not executed in zeroμm so that it is not included in a range. Though the nickel layer and metal are formed by plating, formation is not limited to it and a method such as a vapor deposition, etc., can be used if equivalent film thickness is formed. Thus, the reduction of an electric conductivity caused by the composition change of the electrode on the print substrate 2 owing to heat at the time of reflow soldering is restricted. |
