| 摘要 |
PURPOSE:To cool down a mounted electronic part without decreasing the inner resistance value of power supply or earth patterns due to formation of a recession enabling the patterns to be exposed to a capacitor by cooling down the power supply or earth (GND) layer. CONSTITUTION:A copper sheet 12 is formed after the pattern of a power supply or GND by photoetching process etc., to be held by two each of insulating sheets 3 and then copper foils 1 are arranged both outsides of the insulating sheets to be laminated. Then, specified wiring patterns are formed on both surface and rear side of the copper sheet 1 by photoetching process etc. Next, a recession 14 reaching the copper sheet 12 is formed by machining the position to mount an electronic part and the wiring pattern vacancy on the main surface side. Then, an electronic component (semiconductor element) 5 is cooled down by cooling down the copper sheet 12 after mounting the electronic component 5 on the copper sheet 12 exposed to the recession 14. In such a constitution, the inner resistance value of the patterns of power supply or GND is not varied due to the thickness of copper sheet 12 laminated in several hundred mum even if the pattern of copper sheet 12 is damaged by a minor error in the depth from the surface to the bottom by machining so that the recession 14 may be formed easily. |
