US Patent 11881363 Lighting keyboard, backlight module and lighting board

A backlight module is configured to illuminate at least one key cap. The backlight module includes a light emitting unit, a light guide plate and a lighting board. The light guide plate has a light guide hole for accommodating the light emitting unit. The lighting board has a pair of pads connected to the light emitting unit respectively. The lighting board includes a first reflective layer surrounding the light emitting unit and at least partially covering the pair of pads. Each of the pair of pads has a plurality of branches and at least one hollow area. The at least one hollow area overlaps with at least one part of the light emitting unit.