Lighting keyboard and backlight module thereof

A backlight module configured to illuminate at least one keycap, the backlight module comprising a shielding sheet, an illuminant unit and a lighting board, the backlight module further comprising a first uniform light area surrounding the illuminant unit to make light of the illuminant unit uniform, the first uniform light area comprising:

• a protrusion structure formed at the shielding sheet and protruding towards the lighting board, the protrusion structure diffusing the light of the illuminant unit;
• a pair of footprints located on the lighting board and configured to connect the illuminant unit;
• and
• a first reflective layer located on the lighting board and comprising an inner ring section at least partially covering the pair of footprints, the inner ring section of the first reflective layer reflecting light from the illuminant unit and/or the protrusion structure;
• wherein the backlight module further comprises a second uniform light area surrounding the first uniform light area, the second uniform light area comprises a pair of micro-structure regions apart from each other and located on the first reflective layer, and the pair of micro-structure regions is located at opposite sides of the protrusion structure.