| 摘要 |
PROBLEM TO BE SOLVED: To reduce a temperature difference between solder parts of electronic components having different heat capacities while downsizing the physical constitution in a printed board where the electronic component having a large heat capacity and an electrode located on a lower surface is soldered by reflow solder.SOLUTION: A printed board 11 comprises: an insulation base material 20; and wiring 21 disposed on the insulation base material 20. As wiring, the printed board 11 includes multiple lands 22b disposed on one surface 20a of the insulation base material. Multiple kinds of electronic components, which include a first component and a second component having a heat capacity larger than that of the first component and an electrode located on a lower surface, are soldered to the lands. The insulation base material 20 opens on the one surface 20a and has recessed parts 24 formed so as to correspond to the second component from among the first component and the second component. Each recessed part 24 is formed so as to range from an overlap region 25 overlapping with the second component to the exterior of the overlap region 25. |
