Patent ID: 8866749

Claim:
A backlight module for an operation interface of a portable electronic device, the operation interface comprising at least one keypad, the backlight module comprising: a light guide film, comprising at least one through hole corresponding to the at least one keypad, and filled with a phosphor material into the through hole; a backlight board, installed at a bottom of the light guide film, for reflecting light; and a light emitting unit, installed on a side of the light guide film, for receiving an intermittent power source to generate a light source to an inside of the light guide film; wherein the phosphor material comprises a first surface and a second surface, and according to the phosphor material being liquid with cooled-down and surface-tension dried formation or being powdery with hot pressing formation, the first surface is close to the backlight board and forms a concave down curve by viewing from the backlight board to the light guide film, and the second surface is away from the backlight board and forms a concave up curve by viewing from the backlight board to the light guide film.