Structure Design of TFT LCD Module
The function of TFT LCD liquid crystal display module structure is to provide light source, fix the position of liquid crystal screen and circuit substrate, and avoid direct contact between the edge of circuit substrate and liquid crystal screen and external objects. The design of TFT LCD module is based on the structure design. Next, we will briefly introduce the structural design of TFT LCD module.
The main components of TFT LCD liquid crystal display module include front frame, LCD panel, driver circuit and backlight. The main task of structural design is to evaluate whether the appearance structure and assembly structure of these main components can meet the customer's requirements for product specifications. The LCD structure design is mainly divided into two steps: Basic specification evaluation and shape scheme evaluation.
1、 Basic specification evaluation. It is necessary to confirm the specification summary of the developed LCD products, mainly including the display area size, resolution, module outline size, backlight brightness, etc. For display area evaluation, the dimension from display area to CF glass is often limited by the metal wiring design on TFT glass. PCB and COF evaluation, calculate the required area of PCB substrate according to the circuit diagram, number of components, layout of circuit functional modules and other information. According to the resolution and specifications of the circuit system, roughly determine the shape of the COF with reference to the COF manual. Backlight brightness evaluation: according to the brightness specifications of the developed LCD products and the transmittance of the structure display screen, the brightness required by the backlight can be calculated. The brightness of the backlight is equal to the brightness of the module divided by the transmittance of the display screen. According to the brightness requirements of the backlight and the shape requirements of the module, decide whether to use a high brightness and high thickness straight down backlight or a low brightness and thin side light backlight. In addition, the basic structures supporting and fixing the display screen and backlight, such as front frame, rubber frame, back plate, etc., shall be evaluated, which are usually provided by the backlight manufacturer.
2、 Evaluation of shape scheme. At this stage, it is necessary to integrate the evaluation results of display screen, backlight, front frame, housing, FPC or COF, clarify the overall shape of LCD module, and further evaluate whether the overall shape scheme meets the specification outline of developed LCD products. For the appearance evaluation of the display screen, it is generally required that the center of the display area of the display screen is consistent with the center of the module, and the deviation of up, down, left and right within 3mm is allowed. For the evaluation of backlight, the center of light-emitting area of backlight shall be consistent with the center of display area. The shape evaluation of FPC or COF is mainly to evaluate the crimping position and crimping method. Specifically, it is to evaluate the configuration method that the substrate can be actually assembled, such as L-shaped bending or U-shaped bending. Combined with the configuration of PCB substrate, determine the length and position of COF. Finally, determine whether the substrate and COF can be completely included in the module shape after actual crimping.
The structural design of TFT LCD module should not only achieve the reliability of process, material and assembly in functional design, but also achieve safety, beauty and environmental protection in quality design, so as to improve the cost performance of LCD products. In view of the continuous improvement of the market requirements for the quality of LCD products, Deruxi electronics seeks the best structural design scheme in the system composed of structural design variables such as process, material, connection mode, shape and size, so as to provide customers with high-quality TFT LCD products.