| 摘要 |
PURPOSE:To perform mounting of semiconductor device parts in high density by on both side surfaces of a mounting substrate so that the same external connecting terminals are disposed symmetrical at the acute surfaces. CONSTITUTION:The terminal A of a lead 5 of a package 29 of a normal pattern is soldered to a conductor 32 on the surface of the upper layer 31 of a mounting substrate 30, and a terminal B is soldered to a conductor 33 on the surface of the layer 31. On the other hand, a package 34 of mirror pattern is mounted on the back surface of the substrate 30. The lead 27 of the package 34 is formed in a reverse direction, and a terminal soldered to a conductor 36 on the surface of the lower layer 35 of the substrate 30 becomes a terminal A common to the terminal A. Further, a terminal of the package 34 solder to a conductor 37 on the surface of the lower layer 35 of the substrate 30 is common to the terminal B. Thus, when the package 39 of the normal pattern and the package 34 of the mirror pattern are mounted on both side surfaces of the substrate 30, the same external connecting terminals of the parts 29, 34 of a semiconductor device is disposed at mirror-symmetrical position. |
