Manufacturing Process of Light Guide Plates

Injection Molding

It fills molten molding materials into a closed mold at high pressure, which requires that the light guide plate and microstructure be completed simultaneously during injection molding. The mold price is also quite expensive, so mass production is preferred. Its bottom texture structure can be in the shape of a micro lens, a micro sphere or a tetrahedral corner prism shape, etc. .

Photolithography

Photolithography technology is to apply a layer of corrosion-resistant photoresist on a flat silicon wafer, and then let strong light pass through the photoresist plate, and selectively expose the photoresist plate according to the pattern information of the specific layer produced. Then the developed photoresist is removed, and a thin film with a micro-pattern structure will be left on the upper surface of the silicon wafer. The surface roughness of the light guide plate produced by photolithography is not good, and the loss of light energy is relatively large.

Doping

When the light guide plate is injection molded, a transparent particle material with scattering function is directly injected into the light guide plate. By reasonably adjusting the concentration of the transparent particles, effective control of the light emission is achieved, and ultimately high uniformity of the light emission is achieved. Since the doping process is not easy, Precise control, so the injection molding method is suitable for making small and medium-sized light guide plates. For large-sized light guide plates, uneven light emission will occur.

Laser engraving

The laser engraving production method is to use a computer to strictly control the energy emitted by the laser head and the position of the laser head according to the program requirements, and use vaporization to carve a microstructure array of a certain size on the back of the light guide plate. This method can control the depth of the scattering structure very accurately, but the efficiency is very low and it is not convenient for mass production.

Sandblasting

Use the sandblasting method to make a mold with a rough distribution surface, and transfer the rough distribution on the mold to the light guide plate during injection molding. Where there are more rough surfaces, the scattering ability is stronger. By reasonably adjusting the roughness distribution of the surface, the light distribution on the light-emitting surface can be evenly distributed.