| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a J lead package of a structure, in which a solder wicking phenomenon is less likely to occur in a soldering step. SOLUTION: A J lead L10 has a thickness of 0.4 mm in its upper part and has a thickness of 0.2 mm in its lower end part. The lead L10 has a width of 0.7 mm in its upper part and 0.4 mm in its lower part. The part of the lead having a thickness of 0.4 mm nearly coincides with the part thereof having a width of 0. 7 mm. In the lead L10 of this structure, when the lead is exposed to a vapor atmosphere having a temperature of 215 deg.C, the temperature of the lower part of the lead having a small heat capacity increases toward a vapor temperature more quickly than that of the upper part having a large heat capacity. Solder melted on a conductor of a printed circuit board becomes wet at the lower part of the lead L10 and stays there. Thereby it can be avoided that in several seconds after melting of the solder paste on the conductor, the solder at the lower part of the lead L10 is wicked toward the upper part thereof.</p> |
