| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that a wiring board cannot be firmly joined to an external electric circuit board because of creeping-up of a solder. SOLUTION: This wiring board 7 is provided with an insulation substrate 1 that is provided with an electronic part mounting part and a frame-like metallic layer 3 surrounding the mounting part on its upper surface and a connection pad 4 in the outer periphery of its lower surface, and a castellation conductor 5 that is formed on the side surface of the insulation substrate 1 and connects the connection pad 4 with the metallic layer 3. The castellation conductor 5 is comprised of a first region 5b led from the connection pad 5 and a second region 5c led from the metallic layer 3, and the first and second regions 5b and 5c are out of position in the widthwise direction of the side surface of the insulation substrate 1 and they are connected with each other by means of an internal wiring layer 10 formed inside the insulation substrate 1, and furthermore, recessed parts A and B are formed on the surface of the connection pad 4 and/or the first region 5b. |
