| 摘要 |
PROBLEM TO BE SOLVED: To improve heat resistance, impact resistance and a tone by providing a joined part consisting of a solder material composed of an alloy, in which Sn and Ag as indispensable constituents and further at least two kinds of elements selected from a group consisting of Bi, In and Cu are incorporated, between a part attaching substrate and an electrode. SOLUTION: A solder material is composed of an alloy in which Sn and Ag as indispensable constituents and further at least two kinds of elements selected from a group consisting of Bi, In and Cu are incorporated. The solder material is preferably composed of the alloy consisting of, by weight, 1.0-4.0% Ag, 2.0-6.0% Bi, 1.0-15% In and the balance Sn. In order to restrain brittleness imparted with Bi, 0.1-1.0 weight % Cu is preferably further incorporated in the alloy composing the solder material. Solder having excellent mechanical strength, wettability and a thermal fatigue degree is obtained by using the solder material. |
