The Formula of Photo Resist for Color Filter and Its Technology
|School||Beijing Jiaotong University|
|Keywords||Pigment dispersion method Photoresist Alkali-soluble resin Resolution Chroma|
The color filter color LCD display. In the color filter manufacturing method, the pigment dispersion method is most commonly used, and color photoresists is the most important material in the method. The main component of the color photoresists include: alkali-soluble resin, a photocurable resin, pigments, photoinitiators, organic solvents, and additives. The article focuses on research from the alkali-soluble resin angle and get a good performance photoresist formulations. In addition, the impact and filter some of the details of the preparation process of the other components of the photoresist were compared and discussed. First of all, homemade nine kinds of alkali-soluble resin, according to the acid value is divided into three series. Each series of three kinds of alkali-soluble resin is different, but in between 10,000 to 30,000 molecular weight. Formulated photoresist nine kinds of alkali-soluble resin, respectively, and found that the difference is small, the alkali-soluble resin of the same series can be known little effect of molecular weight on the performance of the photoresist, especially less than 40,000; different series of alkali-soluble photoresist resin formulated distinction can be known acid value greater impact on photoresist. Next, the acid value of the homemade 148.8mgKOH / g of the alkali-soluble resin formulated an excellent performance of the photoresist. The photoresist has a good resolution can be lithographic linewidth 5um stripe pattern and text, and the pattern has a better heat resistance and chemical resistance, the color difference was less than 3, in line with the requirements of actual production. Next, the other components of the photoresist also conducted research, such as a light curing resin and additives, etc.. Was found that when more of the number of functional groups of the photo-curable resin (such as 5 or 6) is easy to form a relatively dense film, after exposure of the photoresist; Further, adding the appropriate epoxy resin can be improved after bake photoresist after the resist pattern of high temperature resistance and chemical resistance, because the crosslinking reaction occurs at a high temperature epoxy resin with an alkali-soluble resin, so that the photoresist layer is more stable; Similarly, added wetting leveling agent, photoresist rheological problems are also improved, so that the layer of the filter is more uniform formation. Finally, we discuss the preparation of the filter part of the details of the process, such as reticle impact on the resolution of the distance to the coating of the photoresist thickness on the chromaticity, the exposure amount of the degree of crosslinking effects. Exposure, the reticle with a photoresist film, the smaller the distance, the better after developing the photoresist pattern resolution. When the thickness of the photoresist coating is increased, the chromaticity of the resist pattern can be improved, but the transmittance will be reduced. Exposure amount is less than 50mJ/cm ~ 2, as the amount of exposure increases, the crosslinking reaction rate faster; exposure amount 50mJ/cm ~ 2 with 100mJ/cm ~ 2 between the cross-linking reaction to continue, but slowed ; exposure greater than 100mJ/cm ~ 2, the crosslinking reaction is substantially complete.