Auxiliary board joining structure

An auxiliary board joining structure comprising:

• a main board (1), an auxiliary plate (10, 10a), a joint pin (17) extending upward from the auxiliary board (10, 10a), and a through-hole (5) for the joint pin (17) formed in the main board (1), wherein the main board (1) and auxiliary board (10, 10a) are electrically and physically joined using a through-hole mounting system in which the joint pin (17) is extended through the through-hole (5), thereby soldering the main board (1) and auxiliary board (10, 10a), the auxiliary board joining structure further comprising:
• a plurality of positioning holes (6, 6a) formed in one of the main board (1) and the auxiliary board (10, 10a);
• a plurality of positioning pins (20, 20a) formed on the other one of the main board (1) and the auxiliary board (10, 10a), wherein the plurality of positioning pins (20, 20a) extend through the corresponding positioning holes (6, 6a) so as to be oriented parallel to the axial direction of the joint pins (17),
• wherein each of the positioning pins (20, 20a) has a height regulating face (23, 23a) for regulating a distance that the positioning pin is extended through the corresponding positioning hole (6, 6a).