Wave soldering device, manufacturing method thereof and printed circuit board

A wave soldering device, comprising:

• a substrate comprising a front surface and a back surface opposite to each other;
• a target hole group comprising a pad through-hole, wherein a plurality of pad through-holes are provided and distributed at intervals along a first direction, the plurality of pad through-holes penetrate through the front surface of the substrate and the back surface of the substrate;
• a virtual hole group comprising a virtual hole, wherein a plurality of virtual holes are provided, and the plurality of virtual holes penetrate through the back surface of the substrate, the plurality of virtual holes are located on the same side of the plurality of pad through-holes in a one-to-one correspondence, a diameter of the virtual hole is less than a diameter of the pad through-hole, a direction from the pad through-hole to the corresponding virtual hole is a second direction, a direction opposite to a direction of the wave soldering device entering a wave soldering equipment is a third direction, an included angle between the second direction and the third direction is less than or equal to 90°, and the third direction is perpendicular to the first direction;
• and
• a connecting line, wherein a plurality of connecting lines are provided and located on the back surface of the substrate, the plurality of virtual holes and the plurality of pad through-holes are connected in a one-to-one correspondence through the plurality of connecting lines.