PURPOSE: To prevent deterioration of insulation resistance due to rust and improve strength of brazing by mixing limited quantity of germanium and platinum to silver.

CONSTITUTION: The material for brazing is made by adding 0.05W10wt% germanium and 0.2W5wt% platinum to silver. Germanium lowers range of using temperature of brazing filler metal and prevents migration of silver, a principal component of the brazing filler metal. When the content is less than 0.05wt%, above-mentioned property is not given, and when it is more than 5wt%, strength of brazing lowers. Platinum is a component that improves wetting property. However, when the content is less than 0.2wt%, above-mentioned property is not given, and when it is more than 5wt%, effect of preventing migration of silver of germanium is deteriorated.