| 摘要 |
PURPOSE:To radiate heat from an electronic part chip in a highly efficient manner by a method wherein a recess is provided by notching the surface layer part of an insulating layer and a metal substrate at a part of the surface of a printed wiring board, and the electronic part chip is mounted in said recess. CONSTITUTION:An insulating layer 2 is adhered on the surface of a metal substrate 1, a circuit conductor 3 is provided on the surface of said insulating layer 2, and a printed wiring board 4 having a metal base is formed. A spot facing work is applied to a part of the surface of the printed wiring board 4, the surface layer part of the insulating layer 2 and the metal substrate 1 is cut, and a recess 6 is formed on the surface of the printed wiring board 4. The insulating layer 2 in the recess 6 is removed, and the metal substrate 1 is exposed in the bottom part of the recess 6. Then, the electronic part chip 5 is mounted in the recess 6, the back side of the electronic part chip 5 is brought to come in contact with the metal substrate 1 at the bottom part of the recess 6, and the electronic part chip 5 is mounted on the printed wiring board 4 by wire bonding 17 and the like between the electronic part chip 5 and the circuit conductor 3. As a result, the heat of the electronic part chip 5 is effectively transmitted to the metal substrate 1 directly, and it is radiated in a highly efficient manner. |
