Structure of organic light-emitting material TFT LCD and the method for making the same

[0002] 1. Field of Invention

[0003] The invention relates to the structure of a TFT (Thin Film Transistor) LCD (Liquid Crystal Display) and the method for making the same. More particularly, the invention relates to the structure of an organic light-emitting material TFT LCD and the method for making the same.

[0004] 2. Related Art

[0005] The light-emitting methods in the existing TFT LCD's can be classified as active and passive ones. Early light-emitting methods are all passive. A backlight source is used at the back of a glass substrate as the light source. A TFT IC (Integrated Circuit) on the glass substrate is used to control the liquid crystal layer between the glass substrate and a transparent conductive glass, so that the liquid crystal layer becomes transparent or opaque. Afterwards, the light passing through the liquid crystal layer is further filtered by color filter plates so that the emitted light can be red, green or blue. Through signal processing, light beams of three different colors are mixed to produce colorful images. This kind of passive light-emitting methods requires the use of a backlight source and the opening of the LCD has to be adjusted to obtain better light intensity.

[0006] With continuous researches and development in light-emitting materials, using light-emitting materials as the light sources of TFT LCD's becomes the trend in modern technologies. Using light-emitting organic materials as the light source in the TFT LCD and using TFT's to control the light-emitting material or the driving circuit for providing a voltage to the light-emitting material can easily control the bright spots on the LCD. The structure and manufacturing method for TFT LCD's can thus be greatly simplified.

[0007] The industry has developed mature technologies in producing red, blue and green organic light-emitting materials. Not only can they be used on an LED (Light-Emitting Diode) body, they can also be used as the light source of TFT displays. Since using organic light-emitting materials as the light sources of TFT displays only requires the use of the photolithographic and etching procedures to define the pattern on an organic light-emitting material layer, the yield can be effectively increased without being limited by the liquid crystal layer.

[0008] Therefore, it is desirable to have a new structure of TFT LCD, which uses red, blue and green light-emitting organic materials as the light source of the LCD and produces colorful images using a photo mask pattern. Furthermore, a manufacturing method for making the above-mentioned light source is proposed to more effectively assemble the LCD's.

[0009] The invention provides a structure of an organic material TFT LCD and its manufacturing method. The invention uses a red-blue-green organic light-emitting pattern layer as the light source of the LCD. TFT's are employed to control whether the organic light-emitting pattern layer emits light.

[0010] The invention provides a structure of an organic material TFT LCD and its manufacturing method. The invention uses a red, blue and green organic light-emitting materials as light sources. The color light emissions are directly modulated and controlled to produce color images without the use of color filters.

[0011] The invention provides a structure of an organic material TFT LCD and its manufacturing method. The invention uses a red, blue and green organic light-emitting materials as light sources. TFT's and a transparent conductive glass layer are used to control the light emissions of the red, blue and green organic light-emitting materials.

[0012] These and other features, aspects and advantages of the invention will become apparent by reference to the following description and accompanying drawings which are given by way of illustration only, and thus are not limitative of the invention, and wherein:

[0013] FIG. 1 is a schematic cross-sectional view of the disclosed LCD, where a glass substrate is formed with TFT's that are further covered by a metal material as a metal contact layer;

[0014] FIG. 2 is a schematic cross-sectional view of the disclosed LCD, where a cover layer is deposited on the TFT's and the metal layer to form a planarized surface; and

[0015] FIG. 3 is a schematic cross-sectional view of the disclosed LCD, where the cover layer is defined with a red organic light-emitting layer, a blue organic light-emitting layer, and a green organic light-emitting layer in order, the top of the organic light-emitting layers is covered with a transparent conductive glass layer, and finally a photo mask layer is defined among the organic light-emitting layers.

[0016] The disclosed organic light-emitting material TFT LCD has a piece of glass as the LCD substrate. The glass substrate is formed with a plurality of TFT's, forming the control circuit of the LCD. A conductive layer is deposited on top of the TFT's, forming a metal contact layer of the TFT's. A flat film layer is then formed on top of the TFT's and the conductive layer. The flat film layer is defined with a red organic light-emitting material pattern, a blue organic light-emitting material pattern, and a green organic light-emitting material pattern. The organic light-emitting material patterns are in alignment with the TFT's so that the TFT's can use voltage to control whether the light-emitting material should emit light. The top of the organic light-emitting material pattern layer is covered with a transparent conductive glass layer as one of the electrodes of the organic light-emitting material pattern layer. Finally, a photo mask pattern layer is deposited on the transparent conductive glass layer to fill the openings among the organic light-emitting material patterns, preventing different colors from mixing with one another.

[0017] With reference to FIG. 1, a glass substrate 100 is provided as the base of a TFT LCD. The top of the glass substrate 100 is formed with a plurality of TFT's 110, forming the control circuit of the LCD. Afterwards, a conductive layer 120 is deposited on top of the TFT's 110, forming a metal contact layer for the TFT's 110. According to a preferred embodiment of the invention, the conductive layer 120 is made of a metal conductive material.

[0018] With reference to FIG. 2, a cover layer 130 is deposited on top of the TFT's 110 and the conductive layer 120, forming a planarized surface. In accordance with a preferred embodiment of the invention, the cover layer 130 is made of polyamide, acrylize, or a transparent photo resist material. The cover layer 130 can also be made of silicon nitride. A chemical machine polishing procedure is employed to planarize the surface of the cover layer 130.

[0019] With reference to FIG. 3, the cover layer 130 is defined with a red organic light-emitting material pattern 151 by first depositing a layer of red organic light-emitting material and then form a desired pattern using photolithographic and etching procedures. Using the same method, the cover layer 130 is further defined with a blue organic light-emitting material pattern 153 and a green organic light-emitting material pattern 152. In accordance with a preferred embodiment of the invention, the red organic light-emitting material is made of a red organic LED material, the blue organic light-emitting material is made of a blue organic LED material, and the green organic light-emitting material is made of a green organic LED material.

[0020] With further reference to FIG. 3, the top of the red, blue, and green organic light-emitting material patterns 151, 153, 152 are deposited with a transparent conductive layer 160. According to a preferred embodiment of the invention, the transparent conductive layer 160 is an ITO material. Finally, a photo mask pattern layer 140 is deposited among the red, blue, and green organic light-emitting material patterns 151, 153, 152 to prevent different colors from mixing with one another. The organic light-emitting patterns are in alignment with the TFT's so that the TFT's can use voltage to control the light emissions from the organic light-emitting patterns.

[0021] While the invention has been described by way of example and in terms of the preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.