JP2006186148A - Manufacturing method of active matrix substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an active matrix substrate capable of forming a pattern with high accuracy, and providing a high productivity. <P>SOLUTION: For example, when gate electrodes 31 each configuring the TFT 30 are formed on a glass substrate 20 as a pattern, the manufacturing method of the active matrix substrate wherein each pixel is formed with a TFT 30, includes a pattern forming process wherein a precursor 21 is coated on the glass substrate 20, a mold 41 fitted to a flat plate 40 made of a porous ceramic is pushed onto the precursor 21 from the upper part of the glass substrate 20 with the precursor 21 applied thereto so as to allow the mold 41 to absorb the precursor. The pattern formation by the stamping method as above allows forming the pattern with high accuracy, and since the porous flat plate 40 also absorbs the precursor 21, the number of replacement times of the mold 41 is decreased. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing an active matrix substrate used in an active matrix display device such as a liquid crystal display device.

  In an active matrix display device such as a liquid crystal display device, a thin film transistor (TFT) is formed in each pixel on a substrate such as glass, and each pixel is driven by this TFT.

  The TFTs on this substrate have been conventionally patterned by a so-called photolithography method, and this photolithography method is used to the extent that almost all can be said at present.

  However, this photolithography method has many problems such as a large number of manufacturing steps and an increase in equipment. Therefore, recently, a method of forming a pattern by a so-called printing method, not the photolithography method, has attracted attention. This printing method is one of the technologies that are greatly expected in the field of electronic devices as a technology capable of reducing energy and capital investment and enabling mass production at low cost.

  As a representative example of this printing method, for example, a transfer method as described in Patent Document 1 is known. The transfer method described in Patent Document 1 will be briefly described. FIG. 2 shows a schematic diagram of the transfer method described in Patent Document 1.

  First, as shown in (a), the resist 2 is contained in the concave portion formed in the printing plate 1, and then as shown in (b), the resist 2 is rotated by rotating the transfer body 3 on the printing plate 1. Is transferred to the transfer body 3, and as shown in (c), the transfer body 3 to which the resist 2 has been transferred is rotated on the substrate 4 on which the non-transfer layer 5 is formed to perform printing.

  It can be said that pattern formation by such a transfer method is excellent as a technique that can be mass-produced at low cost when manufacturing an electronic device as described above.

  However, the TFT formed on the active matrix substrate is required to have very high positional accuracy. In particular, in a display device with higher definition, the TFT becomes finer than before, and the pattern accuracy in forming the TFT is important. In such an active matrix substrate that requires high accuracy, there is a problem that pattern formation by a transfer method is not high enough to satisfy the required accuracy.

  Therefore, in manufacturing an active matrix substrate used in a display device, there is a method disclosed in Patent Document 2 as a printing method capable of forming a pattern with high accuracy.

This method will be briefly described with reference to FIG. 3. First, a resist 11 is applied on the glass substrate 10 as shown in FIG. The flat plate 12 is brought closer from above the glass substrate 10 coated with the resist 11. A mold 13 made of an absorbent material capable of absorbing the resist 11 is integrally attached to the flat plate 12. Then, by pressing the flat plate 10 on the glass substrate, the mold 13 absorbs the resist 13 as shown in FIG. At this time, the mold 13 has a concave portion in an arbitrary shape, and the resist 11 on the glass substrate 10 remains in a convex shape corresponding to the shape of the concave portion, as shown in FIG. By baking the convex resist 11 remaining on the glass substrate 10, an arbitrary shape as shown in (d) can be formed on the glass substrate 10. And TFT is formed on the glass substrate 10 by repeating the process of (a)-(d).
JP 2002-268585 A Special Table 2002-539604

  Since the printing method that presses such a mold is simply to put a flat plate and a glass substrate on top of each other, the pattern can be formed with very high precision compared to the printing method by transfer. It is considered that the manufacturing method is very suitable for manufacturing the active matrix substrate of the apparatus.

  However, since the mold 13 attached to the flat plate 12 absorbs the resist 13 during the printing process as described above, it is necessary to replace the mold 13 every time it is used to some extent. Naturally, as the number of replacements increases, the productivity of the active matrix substrate decreases, and as a result, the cost of the display device increases.

  Accordingly, an object of the present invention is to provide a method for manufacturing an active matrix substrate that can form a high pattern and has high productivity.

  In order to solve the above problems, the present invention provides an active matrix substrate manufacturing method in which a switching element is formed in a region partitioned by a scanning line and a signal line formed in a lattice shape on a substrate. When the pattern is formed, a precursor is applied onto the substrate, and a template attached to a porous flat plate is pressed against the precursor from above the substrate on which the precursor is applied, and the precursor is applied by the template. A step of forming a pattern by absorbing the body is included.

  By the above means, it is possible to form a pattern on the substrate with very high accuracy. In addition, since the precursor can be absorbed by a porous flat plate, the number of times of template exchange can be reduced, and an active matrix substrate with high productivity can be manufactured.

  The present invention uses an imprinting method for pressing a mold among printing methods in manufacturing an active matrix substrate for use in a display device, and also uses a porous material for a flat plate to which the mold is attached. It is.

  BEST MODE FOR CARRYING OUT THE INVENTION In the following, the best mode for carrying out the present invention will be described in detail with reference to the examples and the drawings. However, the following examples are not intended to limit the present invention. .

  The active matrix substrate manufactured according to the present invention is, for example, a liquid crystal display device manufactured by preparing a color filter substrate so as to face the active matrix substrate and sandwiching liquid crystal molecules between the substrates. That is, it can be used for a display device provided with a switching element for each pixel. Further, as is generally known, the switching element is formed in a lattice-like region generated by forming a plurality of scanning lines and a plurality of video lines formed on a glass substrate so as to be orthogonal to each other. Is.

  FIG. 1 shows a part of a process in which the TFT 30 disposed in each pixel according to the present invention is formed on the glass substrate 20. More specifically, among the gate electrode 31, the gate insulating film 32, the semiconductor layer 33, the source electrode 34, and the drain electrode 35 constituting the TFT 30, a process until the gate electrode 31 is formed on the glass substrate 20 is shown. ing. In addition, this process of forming a pattern on the glass substrate 20 is the same as a method of forming a pattern by a conventionally known stamping printing method.

  First, as shown to (a), the precursor 21 containing the electrically-conductive material used as the material of a gate electrode is apply | coated on the glass substrate 20. FIG. Then, a flat plate made of a porous material, specifically, a flat plate 40 made of porous ceramic is pressed against the precursor 21 on the glass substrate 20 from above the glass substrate 20 as shown in FIG. Become.

  At this time, a mold 41 is attached to the lower part of the flat plate 40. The mold 41 has a recess 42 that matches the shape of the gate electrode 31. The mold 41 absorbs the precursor 21, so that the precursor 21 remains on the glass substrate 20 as shown in FIG.

  By firing the precursor 21 remaining on the glass substrate 20, the gate electrode 31 is formed on the glass substrate 20, as shown in (d).

  By repeating the steps (a) to (d) for the gate insulating film 32, the semiconductor layer 33, the source electrode 34, and the drain electrode 35, the TFT 30 is formed on the glass substrate 20. Note that the precursor used for the gate insulating film 32 and the like may be a known one that can be used for forming a stamp-type pattern in the present invention.

  Next, the flat plate 40 and the mold 41 used for forming a pattern on the glass substrate 20 which is a feature of the present invention will be described in more detail.

  First, since the mold 41 needs to absorb the precursor 21, it is made of a material having a high absorbability. The mold 41 is the same as that conventionally known. In general, such a mold 41 is made of a material having a certain degree of elasticity because it directly contacts the glass substrate 20.

  When pressing such a mold 41 against the glass substrate 20, the mold 41 must be pushed in parallel to the glass substrate 20 from the upper part of the mold 41, but only the elastic mold 41 is applied to the glass substrate 20. On the other hand, since a uniform force cannot be applied, a means for supporting the mold is required. There is a flat plate 40 used at that time.

  The flat plate 40 is required to be strong because the elastic mold 41 must be pushed in parallel to the glass substrate 20 as described above. On the side where the mold 41 is attached, if the surface has large irregularities, the flatness of the mold 41 is impaired due to the influence, so the surface of the flat plate 40 is required to be flat. Moreover, since the precision at the time of pressing the casting_mold | template 41 will be impaired if the flat plate 40 expands and contracts greatly with respect to a temperature change, the flat plate 40 is requested | required that there is little elasticity. In the present invention, a porous ceramic is used so that the precursor 21 can be absorbed by the flat plate 40 while satisfying such a requirement.

  Using such a porous ceramic for the flat plate 40 contributes to reducing the number of times the mold 41 is replaced. That is, the template 41 is not capable of absorbing the precursor 21 indefinitely, and after being used to some extent, the template 41 cannot be absorbed. In that case, the work of exchanging the mold 41 is necessary, but by using a porous ceramic for the flat plate 40, the precursor 21 can be absorbed by the flat plate 40 through the mold 41. Therefore, this contributes to reducing the number of times the mold 41 is replaced. And productivity can be improved by reducing the frequency | count of replacement | exchange of the casting_mold | template 41. FIG. In addition, although the ceramic is mentioned as a specific example of the flat plate 40 in this invention, you may consist of a metal provided with porosity in addition to this. In short, the precursor 21 absorbed by the mold 41 may be absorbed by the holes provided in the flat plate 40. However, depending on the material of the flat plate 40, there is a possibility of causing a reaction with the precursor 21, so that a ceramic having low reactivity is more suitable.

  In the above description, it is described that the pattern formation according to the present invention is used in all the steps for forming the TFT 30, but the present invention is not necessarily used in all the steps. It may be used in any of the gate electrode 31, the gate insulating film 32, the semiconductor layer 33, the source electrode 34, and the drain electrode 35 constituting the TFT 30. That is, the TFT 30 may be formed by combining a pattern forming method by a conventional photolithography method and a stamp type pattern forming according to the present invention.

  This may be difficult to manufacture according to the present invention depending on the material of the gate electrode 31 and the like constituting the TFT 30. Therefore, the present invention may be used at a place where the manufacture according to the present invention is most suitable. It goes without saying that the object of the present invention can be achieved in manufacturing an active matrix substrate even if the present invention is applied to some processes constituting the TFT 30 as described above.

  Further, although only the TFT 30 is described as being formed on the glass substrate 20 in the active matrix substrate, the present invention is not limited to the TFT 30, and other switching elements such as so-called MIM elements may be used.

  In addition, the substrate on which the switching element is formed has been described only with respect to the glass substrate in the embodiments, but it is naturally not limited to the glass substrate. For example, an active matrix substrate in which switching elements are formed on a flexible substrate such as a plastic substrate may be used. For a plastic substrate that can only be processed at a low temperature because of its heat resistance, the present invention is effective because it does not require a very high temperature process.

It is the schematic which shows a part of manufacturing process of the active matrix substrate in this invention. It is the schematic which shows a part of manufacturing process of the conventional active matrix substrate. It is the schematic which shows a part of manufacturing process of the conventional active matrix substrate.

Explanation of symbols

20 Glass substrate 21 Precursor 30 TFT
31 Gate electrode 40 Flat plate 41 Mold

Claims (2)

In an active matrix substrate manufacturing method in which switching elements are formed in regions partitioned by scanning lines and signal lines formed in a lattice shape on a substrate,
When forming the pattern of the switching element,
A precursor is applied on the substrate,
A step of forming a pattern by pressing a mold attached to a porous flat plate against the precursor from above the substrate coated with the precursor and absorbing the precursor by the mold; A method for manufacturing an active matrix substrate. The method of manufacturing an active matrix substrate according to claim 1, wherein the flat plate is made of ceramic.

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