Backlight module and illuminated keyboard

An illuminated keyboard, comprising:

• a keyswitch having a light-transmissive character area;
• a light-shielding sheet having a light exit area aligned with the light-transmissive character area;
• a light guide plate disposed under the light-shielding sheet and having a slot hole and a through hole;
• a reflective sheet disposed under the light guide plate and comprising a protrusion and an opening, the protrusion protruding into the through hole;
• a main circuit board disposed under the reflective sheet;
• a light-emitting unit disposed on the main circuit board and passing through the opening to be accommodated in the slot hole, the light-emitting unit being configured to emit light toward the light guide plate, the light reaching the light-transmissive character area sequentially through the light guide plate and the light exit area;
• a flexible circuit board located under the reflective sheet and configured to receive external power;
• and
• an electrical connector electrically connected to the flexible circuit board and the main circuit board, the electrical connector being aligned with the through hole or further protruding into the through hole.