| 摘要 |
PURPOSE:To prevent a disconnection to the minimum possible with a simple structure by forming a connection pattern used to connect both end parts nearly perpendicular to a wiring pattern of a through-hole land to the wiring pattern. CONSTITUTION:In a nearly fan-shaped connection pattern 13, the following are formed: a wide-width part 13a which is extended from both end parts of a through-hole land 11 nearly perpendicular to a wiring pattern 12 to the direction of the wiring pattern and whose size is nearly identical to the diameter of the land 11; a narrow-width part 13b whose size is nearly identical to the width of the wiring pattern 12. The land 11 is connected to the wiring pattern 12 via the connection pattern 13; a connection boundary part can be expanded by the wide-width part 13a of the connection pattern 13; a stress to be exerted is dispersed in the connection boundary part where a stress concentration phenomenon is caused; its limit of metal fatigue can be improved.
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