Fanuc Corporation

Makoto Bekke

Takeshi Sawada

In a leaded electronic component mounting structure in which the effect of reducing the occurrence of a blow hole is not impaired even if resin of a lead-inserted component is softened by heat during soldering and which can reduce a load placed on a lead when an external force acts, the lead of the lead-inserted component is inserted into a through hole provided in a base material of a printed wiring board, soldering is performed by immersing into molten solder, and a surface mount component and a surface mount component pad form an air vent tunnel. The air vent tunnel does not come into direct contact with the lead-inserted component, and therefore is not blocked even if the resin of the lead-inserted component softens due to soldering. Thus, the effect of reducing the occurrence of a blow hole is not impaired.

Mounting structure of leaded electronic component which reduces occurrence of blow hole

A printed wiring board includes three or more than three through holes. An inner wall of the through hole is covered by conductive coating. Same size leads of an electronic component are inserted into the through holes. The through holes are soldered by dip soldering the printed wiring board in melting solder. The through holes have two or more diameters. The diameter of the through hole having more adjacent through holes is not larger than the diameter of the through hole having less adjacent through holes.

Printed wiring board

A PWB having a plurality of through holes into which electronic parts' leads are inserted, and metal plated lands formed around the through holes. The metal plated lands are polygon in which the number of sides is an even number and each pair of facing sides are parallel, and the lands have circular concaves at all the corners and the sides of polygon are arranged to be parallel to the sides of the neighboring metal plated lands.

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Yamanashi, Japan

Makoto Bekke