PRINTED-WIRING BOARD AND WORKING METHOD THEREOF

摘要

PURPOSE:To provide a printed-wiring board wherein the cross-sectional area of a conductor layer inside a through hole can be increased without increasing the number of through holes. CONSTITUTION:A printed-wiring board 22 is provided with a wiring-board body 24 composed of an insulator, with two wiring-patter layers arranged in a mutually separated state by sandwiching the wiring-board body in the thickness direction and with a through hole 28 formed so as to pass the wiring-board body 24 in order to electrically connect the two wiring-pattern layers. In the printed-wiring board, the through hole 28 is formed to be an oval shape which is long along the extension direction of a wiring pattern 26 formed on the two respective wiring-pattern layers and which is short along the width direction of the wiring pattern 26.