Apparatuses for backlighting and manufacturing processes thereof are disclosed. There is provided a backlight module. The backlight module comprises a double-sided circuit board with thermal conducting material as one of the core layers; a plurality of light source components mounted on the first surface of the circuit board; and, a plurality of electronic components mounted on the second surface of the circuit board. The thermal conducting core layer discharges heat generated by the light source components. The circuit board has at least one window on the surface layer at the second surface to expose the thermal conducting core layer for thermal dissipation. As such, the component heights on the illuminating side of the circuit board are unified, and the reflector can be made as a smooth planar sheet to provide a more uniform backlight illumination compared to a single-side circuit board design. Further, such an arrangement reduces the complexity in manufacturing the reflector and hence the cost thereof.