| 摘要 |
PROBLEM TO BE SOLVED: To provide a through wiring board which is excellent for mass production and is low-cost, and has an increased flexibility in arranging a wiring board on which LED devices and optical components are to be mounted. SOLUTION: A conductor pattern is arranged on both opposed faces of insulating substrate. On a wiring board, part of these conductor patterns is electrically conductive by means of a conductor arranged on a through-hole penetrating the insulating substrate. The through-hole of the insulating substrate includes a first through-hole having an inner wall surface exhibiting a small change in relative angle against a substrate side of the insulating substrate, and a second through-hole which has an inner surface with a parabolic cross-section on a surface side and on an opposite side of the insulating substrate, and penetrates the substrate. The average width of the cross-section of the first through-hole is smaller than the minimum width of the second through-hole. COPYRIGHT: (C)2009,JPO&INPIT
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