| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that a wiring board cannot be rigidly connected to an external electric circuit board due to creep-up of a solder. SOLUTION: The wiring board includes an insulation base 1 having an electronic component placing part on an upper surface and a frame state metal layer 3 surrounding the placing part and having a connecting pad 4 to an outer periphery of a lower surface, and a groove state recess 5a covered with a conductor 6 on an inner wall surface by forming a side face of the base 1 by connecting the pad 4 to the layer 3. A small-diameter part 5b smaller in an inner diameter than the other part is formed partly in the recess 5a, and the pad 4 and/or the inner wall surface of the recess 5 covered with the the conductor 6, the surface roughness of which is an arithmetic mean roughness (Ra) of 1.5μm or more. COPYRIGHT: (C)2004,JPO |
