Backlight module having quantum dot and manufacturing method thereof

A backlight module, comprising:

• a light guide part, comprising an incident surface, a bottom surface, and a top surface, wherein the top surface and the bottom surface are opposite surfaces of the light guide part, and the incident surface is located at a lateral side between the bottom surface and the top surface;
• a light source, disposed on a side of the incident surface, being configured to emit light;
• a reflection part, disposed adjacent to the bottom surface of the light guide part;
• a grating, disposed along the top surface of the light guide part, comprising a plurality of bright zones and a plurality of dark zones, and the bright zones have equal pitches;
• a prism sheet, disposed on a plane of the grating, wherein the prism sheet has two opposite surfaces, one of the surfaces next to the grating comprises a plurality of first micro structures, a horizontal cross-section of each first micro structure comprises a first wall and a second wall, a first angle being formed between the first wall and the second wall, and the other surface is a plain surface;
• a diffuser, having a first surface and a second surface, wherein
• the first surface comprises a cave;
• and
• the second surface comprises a convex portion that are formed corresponding to the cave and a flat portion;
• a wavelength-conversion material, disposed in the cave of the diffuser;
• and
• a reflection layer, formed at the flat portion of the second surface.