Backlight module and manufacturing method of light guide film

A backlight module comprises a light guide film, an optical structure layer and a plurality of light emitting sources. The light guide film is provided with a light emitting surface, a first side anda second side, wherein the first side and the second side of the light guide film are opposite to each other, the light emitting surface of the light guide film is connected between the first side andthe second side, the first side of the light guide film has surface roughness, and the surface roughness ranges from about SA 0.06 to about SA 0.075. The optical structure layer is arranged on the light emitting surface. The light-emitting source is located on the first side of the light guide film and is configured to emit light towards the second side through the first side of the light guide film, and the light entering the light guide film is emitted to the optical structure layer through the light-emitting surface. The backlight module can enable the brightness of the edge display area to be more uniform, so the