| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for predicting service life of a mounted section by which the optimum solder shape can be predicted through the prediction of the service life of a mounted section and solder shape. SOLUTION: A value n(d-D)/h is calculated by using a height (h) 16 and diameter (d) 17 of a solder 9 after it is mounted, a diameter D 15 of a parts electrode 5, and a correction constant (n). This value represents the shape of the mounted solder 9, and the thermal fatigue life of the solder 9 varies depending on the value n(d-D)/h. Therefore, when a parameter containing the value n(d-D)/h is used, the shape of the mounted solder 9 having the longest thermal fatigue life time can be predicted without the use of numerical simulation.</p> |
