Coupling structure in wiring board

A coupling structure in a wiring board comprising:

• a printed wiring board;
• and
• a flexible printed wiring board overlaid on the printed wiring board, wherein
• the printed wiring board includes a first conductive line on a surface adjacent to the flexible printed wiring board,
• the flexible printed wiring board includes a second conductive line on a surface on an opposite side from the printed wiring board,
• the flexible printed wiring board includes a conduction-purpose through hole adjacent to the second conductive line and in which a section of the first conductive line is disposed,
• the first conductive line of the printed wiring board and the second conductive line of the flexible wiring board are electrically connected to each other with a conductive member disposed in the conduction-purpose through hole,
• the conductive member is covered with a resin having an insulating property,
• at least one of the printed wiring board and the flexible printed wiring board includes a resin filling-purpose through hole for filling the resin between the printed wiring board and the flexible printed wiring board,
• the resin filling-purpose through hole is filled with the resin,
• the coupling structure further comprises a spacer between the printed wiring board and the flexible printed wiring board,
• the spacer includes a spacer void at a position opposite the conduction-purpose through holes, and
• the resin filling-purpose through hole is at a position opposite an edge of the spacer void.

A wiring board comprising:

• a printed wiring board including:
• a first base including a first surface;
• a first conductive line on the first surface;
• and
• a first coverlay covering the first surface and the first conductive line, the overlay including a first void through which an end portion of the first conductive line is exposed;
• a flexible printed wiring board overlaid on the printed wiring board, the flexible printed wiring board including:
• a second base including a second surface on an opposite side from the first surface of the first base and two through holes;
• a second conductive line between the through holes on the second surface, the second conductive line including side edges aligned with sections of hole edges of the through holes, respectively;
• a second coverlay covering the second surface and the second conductive line, the second coverlay including a second void through which a section of the second conductive line opposite the end portion of the first conductive line is exposed, the second coverlay including two through holes continuing into the through holes of the second base, respectively, sections of hole edges of the through holes being aligned with the side edges of the second conductive line, respectively;
• a solder covering the end portion of the first conductive line and the section of the second conductive line and electrically connecting the end portion of the first conductive line to the section of the second conductive line;
• and
• a resin having an insulating property and filling the first void, the second void, and the through holes, the resin covering the solder.