CN100421018C - A TFT LCD array substrate structure and manufacturing method thereof - Google Patents

Abstract

The invention discloses a structure of a TFT LCD array substrate, comprising: a glass substrate, a thin film transistor array part formed on the glass substrate, wherein a film layer is formed between the glass substrate and the thin film transistor array part, and the film layer can be For polyimide film. The invention also discloses a manufacturing method of the array substrate structure, including: first providing a glass substrate, then pasting a polyimide film on the glass substrate; finally preparing a thin film transistor array part on the surface of the polyimide film. In the invention, unqualified products are found after the detection of the array substrate, and the film and the circuit part on it are removed together, and the glass substrate is recycled and reused, thereby improving the utilization rate of the TFT LCD glass substrate and reducing the production cost.

Description

A kind of TFT LCD array substrate structure and manufacturing method thereof

technical field

The invention relates to a structure of a thin film transistor liquid crystal display (TFT LCD) and a manufacturing method thereof, in particular to a structure of a TFT LCD array substrate and a manufacturing method thereof.

Background technique

Liquid crystal display (LCD) technology has developed rapidly in the past ten years, and great progress has been made in terms of screen size and display quality. After continuous efforts, the performance of all aspects of LCD has reached the level of traditional CRT, and there is a tendency to replace CRT.

With the continuous expansion of LCD production, the competition among various manufacturers is becoming increasingly fierce. While continuously improving product performance, manufacturers are also making continuous efforts to reduce product production costs, thereby enhancing market competitiveness. In the cost of LCD display products, glass substrates occupy a large proportion. In the method of reducing finished products, improving the utilization rate of raw materials, especially improving the utilization rate of glass substrates is one of the general efforts of various manufacturers.

In the process of manufacturing TFT LCD array substrates in the prior art, thin film materials are deposited directly on the glass substrate by methods such as sputtering, PECVD, MBE, etc., and then coated with photoresist on the film, and exposed on the photoresist through a mask. The required pattern is formed, and then the material area not protected by the photoresist is etched away by etching, and finally the photoresist is stripped off. After several cycles of "deposition-photolithography-etching" processes, the required TFT circuit board is finally made. Its specific structure is shown in Figure 1. As shown in FIG. 1 , on the glass substrate 1 are a gate electrode 7 , a gate insulating layer 8 , and an a-Si layer 9 in sequence. On the a-Si are the source electrode and the drain electrode 11 . Above the source and drain electrodes are a passivation layer 12 and a transparent pixel electrode 13 in sequence. Between the a-Si layer 9 and the source and drain electrodes 11 is an N+a-Si layer 10 whose main function is to increase the contact conductivity between the source-drain metal electrodes and the a-Si layer. The passivation layer 12 wraps all parts including the source-drain electrode 11 and the gate electrode 7 to protect the TFT device. Connection holes are provided on the passivation layer 12 at the positions of the source and drain electrodes 11 and the gate electrode 7 respectively. Connection holes open to source and drain metal. A transparent conductive material, such as ITO, is used to prepare a connection line, and a transparent pixel electrode 13 is formed on the source electrode 11 through the connection hole.

In recent years, through the unremitting efforts of engineers, the technology of preparing display elements on organic substrates has become mature. However, due to the low light transmittance of the organic substrate, it has not been used on a large scale in the production of TFT LCD panels. With its excellent light transmittance and chemical stability, glass substrate has always been the main substrate of TFT LCD panel. Due to the high price of glass substrates and the limited yield rate of TFT LCD panel industrial production, unqualified products can only be smashed. Since the unqualified products are only the thin film transistor (TFT) circuit part, for its base glass substrate, there is no change from raw material input to output. Smashing substandard products is a waste of glass substrates, which account for a large proportion of the cost of TFT LCD panels.

Contents of the invention

Aiming at the defects of the prior art, the present invention provides a structure and a manufacturing method of a TFT LCD array substrate, which improves the utilization rate of the glass substrate by pasting a film, thereby reducing the manufacturing cost of the TFT LCD panel.

In order to achieve the above object, the present invention provides a structure of a TFT LCD array substrate, comprising: a glass substrate, a thin film transistor array part formed on the glass substrate, wherein a polyimide film is formed on the glass substrate and the thin film transistor array part between.

In the above solution, the polyimide film is uniformly combined with the glass substrate by atmospheric pressure or adhesive. The polyimide film has high temperature resistance and certain corrosion resistance.

In order to achieve the above object, the present invention simultaneously provides a method for manufacturing the structure of a TFT LCD array substrate, comprising:

Step 1, providing a glass substrate

Step 2, pasting a polyimide film on the glass substrate;

Step 3, preparing a thin film transistor array part on the surface of the polyimide film after step 2.

In the above scheme, the pasting polyimide film in the step 2 is pasted by a dedicated film pasting machine. Or the step of pasting the polyimide film in said step 2 is: first, adopt the method of spraying or sprinkling to form a water film on the surface of the glass substrate; After the polyimide film is correctly positioned on the glass substrate, use a scraper to remove the air bubbles and moisture inside the polyimide film.

Compared with the manufacturing process of the array substrate in the prior art, the unqualified array substrate that appears after the substrate inspection can only be smashed and processed, the present invention uses a layer of polyimide film evenly coated on the glass substrate, and then The typical TFT LCD array substrate manufacturing process is used to prepare the circuit on the polyimide film. If an unqualified product is found after inspection, the film and the circuit part on it are removed together, and the glass substrate is recycled and reused. The invention can recycle the unqualified glass substrate of the array substrate, reduce the manufacturing cost of the TFT LCD panel, prevent the broken glass from generating dust, reduce the discharge of waste, and protect the environment.

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is the sectional view of TFT LCD array substrate structure in the prior art;

Fig. 2 is a cross-sectional view after completing the structural process of the TFT LCD array substrate after the invention of glass substrate film sticking;

Fig. 3 is a schematic diagram of the film removal process after a defect occurs in the manufacturing process of the glass substrate of the present invention;

Fig. 4 is a schematic diagram of the film sticking process on the glass substrate of the present invention;

Fig. 5 is a cross-sectional view after the film is pasted on the glass substrate of the present invention;

Fig. 6 is a cross-sectional view of the first deposition of the gate metal layer after the glass substrate of the present invention is pasted with a film;

Fig. 7 is a cross-sectional view of the first photolithography process after the glass substrate of the present invention is pasted with a film;

Fig. 8 is a cross-sectional view of the first etching process after the glass substrate of the present invention is attached to the film;

Fig. 9 is a schematic diagram of forming a layer of water film on the surface of the glass substrate by spraying or sprinkling according to the present invention;

Figure 10 is a schematic diagram of placing a polyimide film slightly larger in size than a glass substrate on a glass substrate with a water film in the present invention;

Fig. 11 is a schematic diagram of removing internal air bubbles and moisture with a rake-shaped plastic scraper in the present invention.

Marks in the figure: 1. Glass substrate; 2. Polyimide film; 3. Laminating roller; 4. Glass substrate conveying roller; 5. Gate metal layer; 6. Photoresist for gate part; 7. Gate electrode; 8 1. Gate insulating layer; 9. a-Si layer; 10. N+a-Si layer; 11. source and drain electrodes; 12. passivation layer; 13. transparent pixel electrode; 14. water film; 15. scraper.

Detailed ways

Figure 2 shows a cross-sectional view of the structure of the TFT LCD array substrate of the present invention. As shown in FIG. 2 , the structure includes a glass substrate 1 and an array structure formed on the glass substrate 1 , wherein the array structure includes a gate electrode 7 , a gate insulating layer 8 , and an a-Si layer 9 . On the a-Si are the source electrode and the drain electrode 11 . Above the source-drain electrodes are the source-drain insulating layer 12 and the transparent pixel electrode 13 in sequence. Between the a-Si layer 9 and the source and drain electrodes 11 is an N+a-Si layer 10 whose main function is to increase the contact conductivity between the source-drain metal electrodes and the a-Si layer. The passivation layer 12 wraps all parts including the source-drain electrode 11 and the gate electrode 7 to protect the TFT device. Connection holes are provided on the passivation layer 12 at the positions of the source and drain electrodes 11 and the gate electrode 7 respectively. Connection holes open to source and drain metal. A transparent conductive material, such as ITO, is used to prepare a connection line, and a transparent pixel electrode 13 is formed on the source electrode 11 through the connection hole. There is no difference between the above part and the prior art. The present invention differs from the prior art in that there is a polyimide film 2 between the glass substrate 1 and the thin film transistor array. The thickness of the coated polyimide film is about 50 μm, which has little effect on the transmittance of the TFT LCD panel, and overcomes the problem of poor transmittance of the array substrate of the TFTLCD directly prepared on the organic substrate. In addition, since the present invention has a polyimide film 2 between the glass substrate 1 and the thin-film transistor array, when it is found that there are substandard products through the detection of the array substrate, the polyimide film 2 can be attached together with the The thin film transistor array on it is peeled off, as shown in Figure 3, the glass substrate is recycled and put into use again, thereby reducing the manufacturing cost of the TFT LCD panel. The structure of the thin film transistor array on the polyimide film 2 shown in FIG. 2 is only a specific embodiment, and the structure of the thin film transistor array can be changed into any form in the prior art.

The manufacturing method of the array substrate of the present invention will be described in detail below in conjunction with specific embodiments.

Embodiment one:

First of all, using a dedicated film laminating machine, relying on the film laminating roller 3 and atmospheric pressure on it, the polyimide film 2 is evenly pasted on the glass substrate 1 (the glass substrate 1 is placed on the glass substrate conveying roller 4). The method is shown in Figure 4. The specific structure of the cross-section after the polyimide film is pasted is shown in Figure 5. Some polyimide film products have an adhesive coated on one side to help them bond better to the glass substrate.

Then, a gate metal layer 5 is prepared on the polyimide film 2 by using methods such as sputtering, PECVD, MBE or printing, and its cross-sectional specific structure is shown in FIG. 6 . Then coat the photoresist on the film, and form the required pattern on the photoresist by mask exposure method, wherein the photoresist 6 of the gate part remains, and its cross-sectional specific structure is shown in FIG. 7 . The material area not protected by the photoresist is then etched away by etching, and finally the photoresist is stripped off to obtain the gate electrode 7 , whose cross-sectional specific structure is shown in FIG. 8 .

After 3 to 5 cycles of "deposition-photolithography-etching" processes, the required TFT array substrate structure is finally produced. The partial sectional view of the TFT position is shown in Fig. 2 .

The qualified array substrate is then subjected to the typical TFT LCD preparation process, such as cell alignment, liquid crystal injection and other processes to complete the preparation of the TFT LCD display module.

When the array substrate of TFT LCD is tested and found to be unqualified and needs to be scrapped, it is not necessary to use the current method of crushing the substrate and recycling it. It is only necessary to use the polyimide film on the glass substrate together with the polyimide film on it. The TFT array part is peeled off together, and then the glass substrate can be recycled. Its specific implementation method is shown in Figure 3.

Embodiment two:

First, a layer of water film 14 is formed on the surface of the glass substrate by spraying or sprinkling, as shown in FIG. 9 . The function of the water film 14 is to improve the fluidity of the polyimide film, and remove the air bubbles retained on scratches, trachoma, pits and fabric depressions, thereby improving the flatness and uniformity of the film.

Then, a polyimide film with a size slightly larger than the glass substrate was placed on the glass substrate with the water film attached, as shown in Figure 10. After the film is positioned correctly, scrape it from the center to both sides with a rake-shaped plastic scraper 15 with a straight rubber end to remove internal air bubbles and moisture, as shown in Figure 11. If there is a local non-fitting place, heat it with a hair dryer to make the film and the glass completely bonded. After checking that there are no bubbles or wrinkles between the polyimide film and the glass substrate, prepare the required TFT circuit on the film according to the method in Example 1 or other methods in the prior art, and finally make the required TFT circuit. Array substrate of TFT LCD.

The qualified array substrate is then subjected to the typical TFT LCD preparation process, such as cell alignment, liquid crystal injection and other processes to complete the preparation of the TFT LCD display module.

When the array substrate of TFT LCD is tested and found to be unqualified and needs to be scrapped, it is not necessary to use the current method of crushing the substrate and recycling it. It is only necessary to use the polyimide film on the glass substrate together with the polyimide film on it. The TFT array part is peeled off together, and then the glass substrate can be recycled.

In the current TFT LCD process, the highest processing temperature is 350°C, which occurs during the plasma-enhanced chemical vapor deposition (PECVD) process. In the magnetron sputtering process for depositing the first layer of gate material, the processing temperature is 120°C. Polyimide film is a new type of high temperature resistant organic polymer film. It is formed by polycondensation and salivation into a film, and then imidized. It is currently the best performance thin film insulating material in the world, with excellent mechanical properties, electrical properties, chemical stability and high radiation resistance. High and low temperature resistance (-269°C to +400°C). The use of polyimide film as a pasted film layer can meet the requirements of use.

Compared with the manufacturing process of the array substrate in the prior art, unqualified array substrates that appear after the inspection of the substrate can only be smashed and processed. After adopting the present invention, glass substrates of unqualified array substrates can be recycled, which has beneficial effects on reducing the manufacturing cost of TFT LCD panels, preventing dust from being broken by glass, reducing waste discharge, and protecting the environment.

In addition, the core of the present invention is to attach a film that can be torn off on the glass substrate, and then make an array structure part on it. As for the specific form of the array structure, it can be changed to any one in the prior art; in addition, the present invention Although the membrane shown is specifically a polyimide film, other membranes meeting the performance requirements may be substituted.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should use different materials and equipment as required To achieve this, the technical solution of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solution of the present invention.

Claims (6)

1. A structure of a TFT LCD array substrate, comprising: a glass substrate, a thin film transistor array part formed on the glass substrate, characterized in that: a polyimide film is formed between the glass substrate and the thin film transistor array part. 2. The structure of the array substrate according to claim 1, wherein the polyimide film is uniformly combined with the glass substrate by atmospheric pressure or adhesive. 3. The structure of the array substrate according to claim 1 or 2, characterized in that: the polyimide film is a polyimide film with high temperature resistance and corrosion resistance. 4. A method for manufacturing a structure of a TFT LCD array substrate, characterized in that, comprising: Step 1, providing a glass substrate Step 2, pasting a polyimide film on the glass substrate; Step 3, preparing a thin film transistor array part on the surface of the polyimide film after step 2. 5. The manufacturing method according to claim 4, characterized in that: the pasting polyimide film in the step 2 is pasted by a film pasting machine. 6. manufacturing method according to claim 4, is characterized in that: the sticking polyimide film step in described step 2 comprises: First, a water film is formed on the surface of the glass substrate by spraying or sprinkling; Then, the polyimide film is placed on the glass substrate with the water film attached, and after the polyimide film is correctly positioned, the air bubbles and moisture inside the polyimide film are removed with a scraper.

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