Plug connector for board-to-board connector and connector assembly including the same

A plug connector for a board-to-board connector, the plug connector comprising:

• a connector main body which comprises one pair of first sidewalls extending in a first direction and facing each other, and one pair of second sidewalls extending in a second direction perpendicular to the first direction, and facing each other;
• a plurality of plug terminals which are over-molded on the one pair of second sidewalls;
• and
• one pair of fitting nails which are over-molded in the plug connector, wherein each fitting nail comprises:
• an upper surface extending over and covering an upper end of the respective first sidewall of the connector main body;
• a central reinforcement portion extending downward from the upper surface, the central reinforcement portion contacting at least a portion of an outer surface of the respective first sidewall of the connector main body;
• one pair of lateral reinforcement portions, the respective lateral reinforcement portion extending downward from a respective end of the upper surface, the respective lateral reinforcement portion contacting at least a portion of an outer surface of the respective second sidewall;
• a central solder portion extending downward from a lower end of the central reinforcement portion and enclosing at least a portion of a lower surface of the respective first sidewall;
• one pair of arm portions, the respective arm portion extending in the second direction from a respective end of the central reinforcement portion, the arm portions being spaced inwardly of the lateral reinforcement portions;
• and
• one pair of lateral solder portions, the respective lateral solder portion extending downward from the respective arm portion, and encloses at least a portion of a lower surface of the respective second sidewall.