| 摘要 |
PROBLEM TO BE SOLVED: To provide a battery having a small mounting area and a large soldering strength by providing a surface of a lead connected to a negative electrode or a positive electrode of a battery, which contacts with a substrate, with a groove in the longitudinal direction of the lead. SOLUTION: A positive electrode 20 and a negative electrode 30 of a battery main body 10 are respectively formed with a positive electrode lead 40 and a negative electrode lead 50. The negative electrode lead 50 is formed with a U-shaped groove 60 having a cross section, of which top surface is formed into a projecting part and of which lower surface is opened, at a part of the lead, which contacts with a circuit board, as expressed with a figure (b). With this structure provided with the groove 60, length of a soldering filet can be prolonged in comparison with a lead part having the same contact area with a conventional one. As a result, strength of a soldered lead is improved. The melted solder is flowed in along the groove 60 so as to secure the sufficient contact area of the solder, and electrical resistance at the soldering part is lowered. |
