| 摘要 |
PROBLEM TO BE SOLVED: To improve the reliability of the connection between a mounted component and a board in a solder bonding structure containing Bi. SOLUTION: The solder bonding structure of this invention comprises a solder bonding portion for bonding the board and the mounted component together, and the solder bonding portion consists of an alloy containing tin (Sn) and bismuth (Bi). In the solder bonding portion, the bismuth (Bi) is dispersed in the tin (Sn), and in the arbitrary cross-section of the solder bonding portion at ordinary temperatures, the area ratio of the bismuth (Bi) having a diameter of 2μm to the whole dispersed and precipitated bismuth (Bi) is≥70%, so that the reliability of the connection between the mounted component and the board can be improved. COPYRIGHT: (C)2008,JPO&INPIT |
