| 摘要 |
PURPOSE: To prevent dimple-like recesses from being formed at through-holes on the surface of a metal core circuit board. CONSTITUTION: A circuit 3 is formed on the surface of a metal core plate 1 through an insulation layer 2, through-holes 4 are bored through the plate 1, and conductor 6 covered with an insulating resin layer 5 is inserted into each through-hole 4 with the resin layer 5 contacted with the inner wall of the through-hole, thereby connecting the circuit 3. The plate 1, resin layer 5 and conductor 6 are respectively made of materials having linear expansion coefficients of 4.5-30×10<-6> / deg.C. Thus, the difference between the thermal coefficients of any twos of the plate 1, resin layer 5 and conductor 6 is reduced enough to prevent dimple-like recesses from being formed due to the shrinkage difference.
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