| 摘要 |
PURPOSE:To form a chip carrier for an electronic element having preferable heat sink, bonding reliability of a metal board and an electronic part chip and excellent electric connection reliability by using the metal board as part of a substrate. CONSTITUTION:The part of a substrate 3 of a printed circuit board 5 is formed of a metal board 2 having excellent thermal conductivity, a plating layer 17 is formed on the exposed surface of the board 2, and an electronic part chip 6 is mounted on the layer 17. Thus, the heat generated from the chip 6 can be dissipated from the board 2, and an internal head is not accumulated therein by exposing the both side surfaces of the board 2. The layer 17 is formed on the exposed surface of the board 2 to prevent the board 2 from being oxidized. |
