Backlight module light bar lens bonding solution
Jul 04, 2018
Conventional liquid crystal displays use a cold cathode fluorescent lamp (CCFL) as a backlight, which has poor color reproduction and contains mercury vapor which is harmful to the human body. Nowadays, with the development of technology, it has gradually been replaced by LED backlights. The LED backlight has good color reproduction, long life, no mercury, environmental protection, low voltage operation, fast response and convenient control.
The backlight is divided into a direct type backlight and an edge type backlight according to the position of the light source. The direct-type backlight directly places the LED light source under the light-emitting surface, and the light emitted by the light source is diffused and mixed by a space distance and a diffusion plate, and then becomes a surface light source, and the direct-type backlight needs a certain mixing distance. The edge-lit backlight structure is superior to the ultra-thin module design. With the “ultra-thin wind” blowing, large-size ultra-thin side-lit LED backlights have become the research of major TV manufacturers and upstream enterprises. Hot spot.
The entire structure of the LED backlight includes: an LED strip, a driving board, a film, a light guide plate, a heat sink block, an upper frame, a back plate, a lens, and the like. Among them, the bonding between the LED light bar and the lens with an adhesive becomes an important process in the production process.
The light bar is generally a long strip substrate, and the material includes: FR-4, metal, ceramic, alloy, etc., and a specific patch position is marked on the substrate, generally including 3-4 dispensing positions.
Lens, also known as LENS, includes: PC, glass, PMMA, silicone, etc. There are 3 or 4 pins corresponding to the dispensing position on the light bar. The size is usually about φ50px and the lead height is about 1mm.
At present, the common method for fixing the LENS and the light bar is to dispense the glue at the dispensing position of the light bar. The glue needs to have a relatively large viscosity, and the glue type of 0.5-1 mm height is maintained within 3-5 minutes, and then the lens is used. Place it in the corresponding position, insert the pin into the glue, so that the glue completely covers the pin of the lens, and then cure the glue.
