JP2002055359A - Method for manufacturing liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a spacer and a contact hole without reducing an aperture ratio. SOLUTION: An acrylic resin layer 82 is supplied onto a TFT 56 of a transparent insulation substrate 67 and a transfer die 83 having a projecting and recessed part 86 on its surface is pressed to the acrylic resin layer 82 in the uncured state of the acrylic resin layer 82 to form the spacer 79 and the contact hole 59 on the acrylic resin layer 82. Accordingly, the acrylic resin to be removed is easily removed by a projecting part 85 of the transfer die 83. Thus, the amount of the resin remaining in the contact hole 59 is reduced compared with that of conventional technology and a pixel electrode 52 and the TFT 56 is electrically connected reliably. And since the amount of the resin flowing in a recessed part 84 of the transfer die 83 is reduced, the spacer 79 can be made smaller and the aperture ratio is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for a display such as a computer and a television receiver, and uses a thin film transistor (Thin Filtrate) as an address element.
m Transistor: hereinafter abbreviated as TFT) or MIM (Me
The present invention relates to a method for manufacturing a transmissive or reflective liquid crystal display panel including a switching element such as a tal insulator metal (Ta).

More specifically, a gate wiring, a source wiring, and a switching element provided near an intersection of the gate wiring and the source wiring are provided on the same substrate or another substrate. The present invention relates to a method for manufacturing a liquid crystal display panel having a gate electrode connected to a gate wiring, a source electrode connected to the source wiring, and a drain electrode connected to a pixel electrode for applying a voltage to a liquid crystal layer.

[0003]

2. Description of the Related Art Among various liquid crystal display panels, a liquid crystal display panel of the prior art will be described by taking a TFT type liquid crystal display panel as an example. FIG. 9 is a diagram showing a general configuration of an active matrix substrate 1 of a transmission type liquid crystal display panel.

As shown in FIG. 9, an active matrix substrate 1 has a large number of pixel electrodes 2 of tens of thousands to hundreds of thousands or more.
Are formed in a matrix. A TFT 3 serving as a switching element is connected to each of the pixel electrodes 2.
A gate line 7 for supplying a scanning signal is connected to the gate electrode 4 of the TFT 3, and a source line 8 for supplying a display signal (data signal) is connected to the source electrode 5. The drain electrode 6 is connected to the pixel electrode 2 and one electrode of the load capacitance 9, and the counter electrode of the load capacitance 9 is connected to the common line 10.

The driving of the TFT 3 is controlled by a scanning signal input to the gate electrode 4. When driving TFT3,
A display signal is input to the pixel electrode 2 via the TFT 3 and the drain electrode 6. The gate lines 7 and the source lines 8 are formed so as to be orthogonal to each other around the pixel electrodes 2 arranged in a matrix, and at the intersection, the gate lines 7 and the source lines 8 An insulating film is interposed between them.

FIG. 10 is a sectional view of a TFT 3 portion of an active matrix substrate 1 of a TFT type liquid crystal display panel. As shown in FIG. 10, on a transparent insulating substrate 11,
A gate electrode 4 connected to the gate wiring 7 (see FIG. 9) is formed, and a gate insulating film 12 covering the entire gate electrode 4 is formed on the gate electrode 4. A semiconductor layer 13 is formed on the gate insulating film 12 so as to overlap the gate electrode 4, and a channel protection layer 14 is formed on a central portion of the semiconductor layer 13.

[0007] An n + Si layer is formed so as to cover both ends of the channel protective layer 14 and a part of the semiconductor layer 13 and is divided on the channel protective layer 14. One n + Si layer functions as a source electrode 5 and the other n + Si layer functions as a drain electrode 6. A metal layer serving as a source line 8 is formed on the source electrode 5, and a metal layer serving as a connection line 16 connecting the drain electrode 6 and the pixel electrode 2 is formed on the drain electrode 6. Thus, the TFT 3 serving as a switching element and the peripheral structure of the TFT 3 are formed. Further, the TFT 3 and the gate wiring 7
An interlayer insulating film 17 is formed to cover (not shown in FIG. 10) and the upper portion of the source wiring 8.

A transparent insulating film functioning as the pixel electrode 2 is formed on the interlayer insulating film 17, and the pixel electrode 2 is formed through a contact hole 18 penetrating the interlayer insulating film 17.
Connection wiring 16 connected to drain electrode 15 of TFT 3
Connected to.

As described above, the active matrix substrate 1 has the interlayer insulating film 17 interposed between the gate line 7 and the source line 8 and the pixel electrode 2.
The outer periphery of the pixel electrode 2 overlaps a part of the gate line 7 and the source line 8. Such a structure is disclosed, for example, in Japanese Patent Application Laid-Open No. 58-172885. When the active matrix substrate 1 has the above-described structure, the aperture ratio of the liquid crystal display panel is improved. Further, in this liquid crystal display panel, the electric field caused by the gate wiring and the source wiring is shielded, so that disclination, which is a phenomenon in which the alignment of liquid crystal molecules is broken, can be prevented.

The gate insulating film 12 and the interlayer insulating film 17 are made of an inorganic film such as silicon nitride (SiN) by CVD.
The thickness is 300 to 500 nm by the chemical vapor deposition method (Chemical Vapor Deposition).
(0.3 to 0.5 μm). If the thicknesses of these films 12 and 17 are not made larger than this, it takes a long time for deposition to deteriorate production efficiency, the substrate 11 warps due to residual stress, and defects such as cracks 21 increase. That's why.

On the other hand, as the interlayer insulating film 17, an organic film can be used instead of the above-mentioned inorganic film. At this time, the interlayer insulating film 17 is formed to have a thickness of about 1 to 5 μm. As described above, by using the organic insulating film as the interlayer insulating film 17 and setting its thickness to 1 to 5 μm, it is possible to improve the aperture ratio, improve the luminance, and reduce the power consumption of the backlight. In some cases, the step of forming a light-shielding film that hides a region where alignment is disturbed is simplified, and a liquid crystal display panel using both a transmission type and a reflection type can be manufactured.

A liquid crystal display panel is formed by injecting a liquid crystal between the active matrix substrate 1 and a counter substrate facing the active matrix substrate 1 with a space being maintained between the substrates by a spacer. The spacers are scattered on the active matrix substrate 1 or formed on the active matrix substrate 1 by a photolithography method.

In the above method of dispersing the spacers, the dispersed spacers have an unspecified arrangement.
There is a problem that spacers enter the region.
As a result, the display quality of the liquid crystal display panel is reduced, and a defect may occur. Furthermore, since the stability of the step of dispersing the spacer is low, there is a problem that the sampling inspection needs to be performed more than other steps.

The method of forming spacers by photolithography has a problem that an expensive exposure apparatus is required and the number of exposure steps increases.

The prior art which solves the above-mentioned problems is as follows.
It is disclosed in JP-A-10-26041. FIG.
1 is a diagram showing a prior art disclosed in Japanese Patent Application Laid-Open No. 10-26041. This publication proposes a method in which an organic insulating film 22 is used as an interlayer insulating film, and contact holes and spacers are collectively formed in the organic insulating film 22 by a press process. More specifically, a flat mold 25 in which a convex portion 23 for forming a contact hole and a concave portion 24 for forming a spacer are formed on the cured organic insulating film 22 by pressing the entire surface. The resin that has been pushed away by the convex portions 23 of the mold 25 is moved to the concave portions 24 of the mold. Therefore, type 2
The organic insulating film portion pushed away by the convex portion 23 of the mold 5 functions as a contact hole, and the organic insulating film portion moved to the concave portion 24 of the mold 25 functions as a spacer.

[0016]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
No. 041 has the following problems. First, since the configuration is such that the organic insulating film 22 obtained by curing the mold 25 is pressed, there is a problem that a large pressing force for pressing the mold 25 is required. As described above, when the mold 25 is pressed against the cured organic insulating film 22 with a large pressing force,
There is a problem that the parallelism between the substrate 26 and the mold 25 is displaced, so that the spacers and the contact holes are not formed at predetermined positions, or that the substrate 26 is easily broken by the inclusion of foreign matter.

Further, if the rigidity and flatness of the stage 27 on which the substrate 26 is mounted are low, it is difficult to form the organic insulating film 22 to a uniform thickness, and there is a problem that the processing accuracy is reduced.

When the substrate 26 is a large substrate having a size of about several hundred mm square, the mold 25 and the organic insulating film 22 are in close contact with each other in a large area during pressing, so that mold separation is poor and moldability is poor. This also has the problem that the processing accuracy is reduced.

Further, even if the mold 25 is pressed against the organic insulating film 22 with a large pressing force, it is difficult to completely remove the resin in the contact hole. Moreover, the pixel region adjacent to the contact hole has a larger area than the contact hole, and the pixel region is pressed by the mold 25, so that the resin in the contact hole hardly flows out. Therefore, a problem that a thin resin film remains in the contact hole occurs, and the contact resistance increases. Furthermore, when the switching element 28 is connected in multiple terminals like a TFT, a connection failure is likely to occur. In addition, when the substrate 26 is large, there is a problem that the connection failure is further reduced due to the variation in the pressure of the mold 25, the connection non-defective rate is reduced, and the reliability is reduced.

In order to improve the fluidity of the resin, a method of increasing the amount of resin flowing into the concave portion 24 of the mold 25 can be considered. However, if the spacer becomes large, the light-shielding region increases, and the aperture ratio increases. Will drop.

Accordingly, an object of the present invention is to provide a method for manufacturing a highly reliable liquid crystal display panel which can be produced efficiently, reduce the occurrence of substrate cracks and defective contacts, and a liquid crystal display panel manufactured by this method. It is to provide.

Another object of the present invention is to provide a method of manufacturing a liquid crystal display panel in which a spacer and a contact hole can be formed without lowering the aperture ratio. An object of the present invention is to provide a liquid crystal display panel having a good electrical connection with the element.

[0023]

SUMMARY OF THE INVENTION The present invention comprises a first and a second substrate facing each other, a spacer for maintaining a predetermined distance between the first and the second substrate, and a spacer between the first and the second substrates. A liquid crystal layer interposed in the first substrate, a pixel electrode provided on the first substrate for controlling the direction of liquid crystal, and an active element provided on the first substrate for controlling the pixel electrode, comprising: An organic insulating film is supplied on the active element on the first substrate, a transfer mold having an uneven portion on the surface is opposed to the organic insulating film, and the transfer mold is completely uncured or softened. Is pressed onto the organic insulating film to transfer the concave and convex portions to the organic insulating film, thereby forming a spacer formed of a convex portion and a contact hole formed of a concave portion on the organic insulating film, and the spacer and the contact hole are formed. Isolated organic insulation Above, by forming an electrode film to be a pixel electrode, and said pixel electrode and said active element,
This is a method for manufacturing a liquid crystal display panel, wherein the liquid crystal display panel is electrically connected via a contact hole.

According to the present invention, an organic insulating film is provided on the active element of the first substrate, and the organic insulating film is completely uncured or softened by heat or the like, and has a surface having an uneven portion. The mold is pressed against the organic insulating film to transfer the irregularities to the organic insulating film. As a result, a spacer having a convex portion and a contact hole having a concave portion are formed in the organic insulating film. As described above, since the uneven portion is transferred to the organic insulating film in a state where the organic insulating film is uncured or the like, even if the pressing force when pressing the transfer mold against the organic insulating film is small, the organic insulating film is formed with the spacer. A contact hole can be reliably formed. Further, since the pressing force is small as described above, it is possible to prevent the first substrate from being out of parallel with the transfer mold during the transfer of the concave and convex portions. Further, it is possible to prevent the first substrate from being cracked when foreign matter is involved in the transfer of the uneven portion.

Further, as described above, since the pressing force of the transfer die can be small, it is easy to make the thickness of the interlayer insulating film portion excluding the spacer and the contact hole of the organic insulating film uniform. Processing accuracy is improved. Furthermore, since the organic insulating film is in an uncured state or the like, even if the first substrate is a large substrate having a size of several hundred mm square or more, the transfer mold release and moldability are better than those of the prior art. . This also improves the processing accuracy.

In addition, since the uneven portion is transferred in an uncured state of the organic insulating film, the resin of the organic insulating film which is removed by the transfer-type convex portion is easily removed. As a result, the amount of resin remaining in the contact holes is reduced as compared with the prior art. Therefore, electrical connection between the pixel electrode formed on the organic insulating film after the transfer and the active element is ensured. As a result, like a TFT type liquid crystal display panel,
Even when the active element is connected to multiple terminals, poor connection hardly occurs, the non-defective connection rate is improved, and the connection reliability is improved.

Further, when the transfer mold is pressed, the amount of resin flowing into the concave portion of the transfer mold is reduced because the organic insulating film has good fluidity. That is, the spacer formed on the organic insulating film can be reduced. Therefore, the light blocking area is reduced and the aperture ratio is improved. As a result, higher luminance and lower power consumption of the liquid crystal display panel can be achieved.

In the prior art, when the peripheral wall of the organic insulating film facing the contact hole is formed into a tapered shape, the taper angle is formed by etching, so that the conditions for processing into a tapered shape are severe. . In contrast, the method for manufacturing a liquid crystal display panel according to the present invention has a configuration in which a contact hole is formed in an organic insulating film by pressing a transfer-type convex portion against the organic insulating film.
By making the projection of the transfer type tapered, the peripheral wall of the organic insulating film facing the contact hole can be easily tapered. Furthermore, even if the first substrate is a large substrate, the variation in processing accuracy is reduced on the whole,
Problems such as poor connection are reduced. Further, it is preferable that the taper angle be selected from the range of 30 ° C to 60 ° C. This reduces connection failures such as disconnection.

Further, the present invention is characterized in that only the surface portion of the organic insulating film where the spacer and the contact hole are formed is uniformly removed by etching.

According to the present invention, after forming a spacer and a contact hole in an organic insulating film by a transfer type,
The surface of the organic insulating film is uniformly removed by etching. Therefore, the organic insulating film on the active element can be supplied relatively thick. Thereby, the pressing force of the transfer mold can be small, and the deviation of the parallelism between the first substrate and the transfer mold at the time of transfer can be prevented. Furthermore, even if foreign matter is involved, the first substrate can be prevented from cracking.

Even if the organic insulating film remains in the contact hole after the transfer, the remaining organic insulating film can be completely removed during this etching step. Therefore, the active element and the pixel electrode are reliably connected. As a result, even when the active elements are connected to multiple terminals as in a TFT type liquid crystal display panel, poor connection is unlikely to occur, the non-defective connection rate is improved, and the connection reliability is improved.

Further, in the present invention, the transfer mold is an arc-shaped member having an uneven portion formed on a surface, and the uneven portion is transferred to the organic insulating film while the transfer mold is angularly displaced around an axis. It is characterized by the following.

According to the present invention, the concave-convex portion is transferred to the organic insulating film by angularly displacing the arc-shaped transfer mold having the concave-convex portion on the surface around the rotation axis, and the spacer is transferred to the organic insulating film. And a contact hole are formed. That is, since the uneven portion is transferred in a state where the transfer mold and the organic insulating film are in point contact with each other, the pressing force can be significantly reduced.

Further, the present invention is characterized in that the organic insulating film is made of a photocurable resin. According to the present invention, since the organic insulating film is made of a photocurable resin, the residual stress is small and the processing accuracy is good as compared with the thermosetting resin. Furthermore, even if the organic insulating film is supplied to a relatively large thickness, the organic insulating film can be cured in a short time, and the production efficiency is good.

Further, the present invention is characterized in that the organic insulating film is made of an acrylic resin.

According to the present invention, since the acrylic resin has a relatively low relative dielectric constant, even if the pixel electrode and other wiring are overlapped with a large area and overlapped, the pixel electrode and other wiring may not overlap. The capacitance component between them can be reduced. Thus, disturbance of a signal input to the pixel electrode can be reduced. Therefore, the aperture ratio can be improved while maintaining high display quality. Further, since the acrylic resin has a relatively high transparency, coloring of an image displayed by the liquid crystal display panel can be reduced. Therefore, the high brightness state of the liquid crystal display panel can be maintained, and a bright image can be displayed with low power consumption.

Further, the present invention is characterized in that the organic insulating film is optically decolorized. According to the present invention, the optical transmittance of the organic insulating film is improved by performing the optical decolorization treatment on the organic insulating film. As a result, a high luminance state can be maintained, and a bright image can be displayed with low power consumption.

Further, the present invention is characterized in that the organic insulating film is decolorized chemically. According to the present invention, the light transmittance of the organic insulating film is improved by performing the chemical decolorizing treatment on the organic insulating film. As a result, a high luminance state can be maintained, and a bright image can be displayed with low power consumption.

Further, the present invention is characterized in that the organic insulating film is made of a resin having a photosensitive wavelength peak near 365 nm.

According to the present invention, a resin having a photosensitive wavelength peak near 365 nm is used as the organic insulating film. Such a resin does not react to light leakage in the visible light region during the manufacturing process of the liquid crystal display panel. Therefore, it does not cure in response to the leaked light, and can improve the processing accuracy of the contact hole and the like, and can maintain high display quality because of relatively little coloring.

[0041]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the liquid crystal display panel of the present invention will be described by taking a TFT type liquid crystal display panel as an example. Note that the liquid crystal display panel of the present invention uses the TF
It is not limited to a T-type liquid crystal display panel. FIG. 1 is a plan view showing a configuration of one pixel portion of an active matrix substrate 51 constituting a transmission type liquid crystal display panel according to an embodiment of the present invention.

As shown in FIG. 1, on the active matrix substrate 51, a plurality of pixel electrodes 52 are provided in a matrix. A plurality of gate lines 54 and a plurality of source lines 55 pass around these pixel electrodes 52.
The gate wiring 54 and the source wiring 55 are orthogonally different from each other. A scanning signal flows through the gate wiring 54, and a display signal flows through the source wiring 55. Further, the outer peripheral portion of the pixel electrode 52 is disposed on one surface side of the gate wiring 54 and the source wiring 55 (on the near side in FIG. 1) via the interlayer insulating film 77.

A thin film transistor 56 (hereinafter, abbreviated as TFT 56) as an active element is provided near one of the intersections 65a among the intersections 65a to 65d of the gate wiring 54 and the source wiring 55 surrounding the pixel electrode 52. ) Is provided. The TFT 56 has a gate electrode 62, a source electrode 63, and a drain electrode 64. A gate wiring 54 is connected to the gate electrode 62 of the TFT 56, and the driving of the TFT 56 is controlled by a scanning signal input from the gate wiring 54 to the gate electrode 62. The source wiring 55 is connected to the source electrode 63 of the TFT 56, and a display signal is input from the source wiring 55 to the source electrode 63. Further, the drain electrode 64 of the TFT 56 is connected to the pixel electrode 52 via the connection wiring 58 and the contact hole 59.

Further, the drain electrode 64 is connected to the connection wiring 58
Is connected to the load capacitance electrode 60 via the. The load capacitance electrode 60 is provided orthogonal to the connection wiring 58. Also, a load capacitance counter electrode 61 facing the load capacitance electrode 60.
Are provided in common to the pixel electrodes 52 of each column arranged in parallel (in the horizontal direction in FIG. 1) with the gate wiring 54 and are electrically connected. The load capacitance electrode 60 and the load capacitance counter electrode 61 constitute a load capacitance 66.

FIG. 2 is a sectional view taken along the line AA of FIG. As shown in FIG. 2, a gate electrode 62 is provided on a flat transparent insulating substrate 67 (first substrate), and a gate insulating film 68 is provided on the gate electrode 62 and the transparent insulating substrate 67. A semiconductor layer 69 is provided on the gate insulating film 68 so as to overlap the gate electrode 62, and a channel protection layer 70 is provided on a central portion of the semiconductor layer 69. The channel protection layer 7 covers both ends of the channel protection layer 70 and a part of the semiconductor layer 69.
The n + Si layer is provided in a state of being separated on the zero. One n + Si layer functions as a source electrode 63, and the other n + Si layer functions as a drain electrode 64.

The end of the source electrode 64 is covered with ITO
A first transparent conductive film 72 is provided, and a first metal film 73 is provided on the first transparent conductive film 72. these,
The first transparent conductive film 72 and the first metal film 73 become the source wiring 55 having a two-layer structure. Thus, the source wiring 55 is
With the two-layer structure, the TFT 56 and the source electrode 64 are electrically connected by the first transparent conductive film 72 even if a part of the first metal film 73 is defective. That is, it is possible to reduce connection failure due to disconnection of the source wiring 55 or the like.

The end of the drain electrode 64 is covered with
A second transparent conductive film 74 of O or the like is provided, and a second metal layer 75 is provided so as to cover an end of the second transparent conductive film 74. The second transparent conductive film 74 extends in the same direction as the direction in which the source wiring 55 extends (the left-right direction in FIG. 2),
The drain electrode 64 is connected to the pixel electrode 52, and the load capacitance electrode 60, which is one electrode of the load capacitance 66,
Connected to. That is, the extension of the second transparent conductive film 74 functions as the connection wiring 58. Further, a load capacitance counter electrode 61 which is the other electrode of the load capacitance 66 is provided on the transparent insulating substrate 67 so as to face the load capacitance electrode 60. Further, the TFT 56, the gate wiring 54, the source wiring 55 and the connection electrode 58
Further, an interlayer insulating film 77 which is an organic film having an insulating property is provided.

As described above, the drain electrode 6 of the TFT 56
4 and the connection wiring 58 connecting the pixel electrode 52
By using the second transparent conductive film 74, the following advantages can be obtained.

That is, in the active matrix substrate 1 of the prior art shown in FIG. 10, since the connection wiring 16 is formed of a metal film, the presence of the connection wiring 16 in the opening causes a decrease in the aperture ratio. I was In order to prevent this, in the prior art, a connection wiring 16 is formed on the drain electrode 6 of the TFT 3, an interlayer insulating film 17 is formed thereon, and a contact hole 18 is formed in the interlayer insulating film 17 on the connection wiring 16. Forming the drain electrode 6 and the pixel electrode 2
0 was electrically connected. However, according to this conventional technique, when the size of the TFT 3 is reduced in order to improve the aperture ratio, the contact hole 18 cannot be provided directly above the TFT 3. Therefore, TFT3
There is a problem that the aperture ratio cannot be improved even if the size is reduced.

In the prior art active matrix substrate 1 shown in FIG. 10, when the interlayer insulating film 17 is formed to a thickness as large as several μm, the pixel electrode 20 and the connection wiring 16 are reliably electrically connected. In order to make contact, the shape of the peripheral wall of the interlayer insulating film 17 facing the contact hole 18 had to be tapered. Further, since the contact hole 18 is formed on the connection wiring 16, in order to connect the pixel electrode 2 and the connection wiring 16 without light leakage,
It was necessary to increase the area of the connection wiring 16. For example, when the diameter of the contact hole 18 is 5 μm, the length of one side of the connection wiring 16 is 14 in consideration of the tapered region of the contact hole 18 and the alignment accuracy.
About μm is required. Therefore, in the conventional active matrix substrate 1, the TF having a smaller size
When T3 was formed, the aperture ratio was reduced due to the connection wiring 16.

On the other hand, in the active matrix substrate 51 of the present embodiment shown in FIG.
Since it is formed of the second transparent conductive film 74, the aperture ratio does not decrease.

Further, the pixel electrode 52 as a third transparent conductive film is provided on the interlayer insulating film 77. This pixel electrode 5
2 is connected to the connection electrode 58 via a contact hole 59 penetrating the interlayer insulating film 77. Therefore, the pixel electrode 52 is connected to the drain electrode 64 of the TFT 56 via the connection wiring 58.

Further, a source wiring 55 and a gate wiring 54
A spacer 79 is formed at the intersection 65 with the same material as the interlayer insulating film 77. The opposing substrate (second substrate) 80 is disposed so as to face the active matrix substrate 51 configured as described above, and the active matrix substrate 51 and the opposing substrate 80 held by the spacer 79.
The liquid crystal layer 81 is interposed in the gap between the TFT and the liquid crystal display panel 91 of the TFT type according to the embodiment of the present invention.

Next, a method of manufacturing the liquid crystal display panel according to the first embodiment of the present invention will be described with reference to an example in which the above-described TFT type liquid crystal display panel 91 is manufactured. Note that the method of manufacturing a liquid crystal display panel of the present invention uses this TFT.
The present invention can be applied not only when manufacturing the liquid crystal display panel 91 but also when manufacturing other liquid crystal display panels.

FIG. 3 shows a TFT 5 on a transparent insulating substrate 67.
FIG. 4 is a diagram showing a state immediately after the formation of the TFT 56. FIG.
FIG. 5 is a view showing a state immediately after an acrylic resin layer 82 is formed on a transparent insulating substrate 67 on which a transfer mold 8 is formed.
3 is a diagram showing a state in which the concave and convex portions 90 are transferred to the acrylic resin layer 82 by using the acrylic resin layer 8.
FIG. 4 is a diagram showing a state in which an uneven portion 90 has been transferred to FIG.

First, as shown in FIG. 3, a gate electrode 6 is placed on a transparent insulating substrate 67 (first substrate) such as a glass substrate.
2. n to be the gate insulating film 68, the semiconductor layer 69, the channel protective layer 70, the source electrode 63 and the drain electrode 64
A + Si layer is sequentially formed. After that, the first and second transparent conductive films 7 to be the source wiring 55 and the connection wiring 58
2, 74 and metal films 73, 75 are formed by a sputtering method, and after the film formation, are patterned into a predetermined shape. The steps of forming each of these members are the same as those in the method for manufacturing an active matrix substrate of the prior art, and thus detailed description is omitted.

After forming each member on the transparent insulating substrate 67 as described above, as shown in FIG. 4, a photo-curable acrylic resin to be an interlayer insulating film 77 is applied by, for example, a spin coating method. , Apply evenly. Thereafter, the applied acrylic resin layer 82 is dried by heating it at, for example, about 100 degrees for 5 minutes, so that the acrylic resin 82 is in a semi-cured state. The application condition and heating condition of the acrylic resin are such that the thickness of the acrylic resin layer 82 in the semi-cured state is, for example, 3.3 μm to 3.5 μm.
It is preferable to determine the degree.

Next, as shown in FIG. 5, a concave portion 84 is formed above the transparent insulating substrate 67 on which the acrylic resin layer 82 is formed.
Mold 83 having a concave-convex portion 86 including a convex portion 85
And the transfer mold 83 is pressed against the acrylic resin layer 82 in a semi-cured state (the lower part in FIG. 5). Thereby, as shown in FIG. 6, the transfer mold 83 is formed on the acrylic resin layer 82.
The uneven portion 86 is transferred, and the uneven portion 90 is formed on the acrylic resin layer 82. As shown in FIG. 5, one surface of the transfer die 83 on which the uneven portions 86 are formed has a curved shape. In this way, a convex portion 89 having a thickness of about 4.5 μm and a concave portion 88 having a thickness of approximately 3.5 μm are formed on the acrylic resin layer 82, and the convex portion 89 functions as a spacer 79, 88 functions as the contact hole 59. The uneven portions 8 of the acrylic resin layer 82 after the transfer
6 is compressed to a thickness of about 3.0 μm or the surface is removed by etching later.
Function as

Next, the acrylic resin layer 82 on which the uneven portions 90 are formed is hardened by exposing the entire surface to the acrylic resin layer 82. Thereafter, as shown in FIG. 2, a third transparent conductive film serving as the pixel electrode 52 is formed by sputtering and patterned. In this way,
The pixel electrode 52 is electrically connected to a connection wiring 58 connected to the drain electrode 64 of the TFT 56 via a contact hole 59 penetrating through the interlayer insulating film 77 in the thickness direction. Note that, in order to further secure the connection state between the pixel electrode 52 and the connection wiring 58, the contact hole 5
9 or only one surface of the acrylic resin layer 82 may be slightly etched, for example, to a thickness of about 0.5 μm.

As described above, the active matrix substrate 51 of the liquid crystal display panel 91 according to one embodiment of the present invention
Can be manufactured. A counter substrate 80, which is a second substrate, is arranged to face the active matrix substrate 51, and a liquid crystal layer 81 is injected between these substrates 51, 80, thereby achieving one embodiment of the present invention shown in FIG. The liquid crystal display panel 91 of the embodiment is manufactured.

The active matrix substrate 51 manufactured as described above includes a gate wiring 54 and a source wiring 55
Since an interlayer insulating film 77 having a relatively large film thickness is interposed between the TFT 56 and the pixel electrode 52, FIG.
As shown in FIG. 5, the outer peripheral portion of the pixel electrode 52 is
4 and the source wiring 55,
Further, the surface of the active matrix substrate 51 can be flattened. Therefore, the liquid crystal display panel 91 shown in FIG. 2 can improve the aperture ratio as compared with the liquid crystal display panel of the prior art, can shield the electrolysis caused by the wirings 54 and 55, and reduce disclination. Can be suppressed.

As shown in FIG. 2, in the active matrix substrate 51 of the present embodiment, the connection wiring 58
A load capacitance counter electrode 61 opposing a load capacitance electrode 60 which is one electrode of the load capacitance 66 connected to the common electrode (not shown) is formed on a counter substrate 80 by a common wiring (not shown). It is configured to be connected to. Further, a contact hole 59 penetrating through the interlayer insulating film 77 is formed on one surface side (upper in FIG. 2) of the load capacitance electrode 60 and the load capacitance counter electrode 61. That is, the contact hole 59 is formed on one surface side of a common wiring (not shown) made of a light-shielding metal film.

In the present embodiment, as described above, the thickness of the interlayer insulating film 77 is about 3.0 μm. Since the thickness of the liquid crystal layer 81 is not negligible as compared with about 4.5 μm, which is the thickness of the liquid crystal layer 81, light leakage may occur due to disturbance of the alignment of the liquid crystal around the contact hole 59. Therefore, if the contact hole 59 is formed in the opening of the transmissive liquid crystal display panel, the light leakage may cause a decrease in contrast.

On the other hand, in this embodiment, the contact hole 59 is connected to the end of the common wiring (not shown) and is formed above the load capacitance counter electrode 61 and the load capacitance electrode 60 made of a light-shielding metal film. Are formed, so that problems such as light leakage and a decrease in contrast as described above do not occur. That is, the contact hole 5
9 is provided above the light-shielding metal film, even if light leakage occurs due to disorder in the alignment of the liquid crystal, the region where the light leakage occurs is the light-shielding portion other than the opening, so that the contrast is low. Does not decrease.

Further, when a load capacitance is formed by using a part of the gate wiring 54 as a load capacitance electrode, a contact hole may be formed on the gate wiring 54. By forming a contact hole on the gate wiring 54 in this manner, light leaked from the contact hole can be blocked by the gate wiring 54, so that a decrease in contrast can be prevented.

Since the light leaking from the lower part of the contact hole 59 is shielded by the load capacitance counter electrode 61, it is not necessary to make the dimensional accuracy of the contact hole 59 strict. That is, as shown in FIG. 1, the contact hole 59 may be formed without protruding from above the load capacitance counter electrode 61. Therefore, the contact hole 59 can be formed large and smooth with a margin, thereby preventing a problem that the pixel electrode 52 formed on the interlayer insulating film 77 is interrupted by the contact hole 59. Also, the yield is improved as compared with the prior art.

The relative permittivity of the acrylic resin constituting the interlayer insulating film 77 is about 3.4 to 3.8, which is lower than that of an inorganic film (for example, the relative permittivity of silicon nitride is 8). It is low and its transparency is high. Further, since the acrylic resin can be easily formed to a thickness of 3 μm or more by a spin coating method, the capacitance between the gate wiring 54 and the pixel electrode 52 and the capacitance between the source wiring 55 and the pixel electrode 52 are reduced. , Can be lower. This reduces the time constant. Thereby, each wiring 5
Crosstalk caused by a capacitance component between the pixel electrodes 52 and the pixel electrode 52 on image display (leakage of a drive signal into unnecessary parts)
And the like can be further reduced, and a bright display screen can be obtained. Further, when a photocurable acrylic resin is used, a thin film can be formed by a spin coating method. Therefore, a resin thin film having a thickness as thick as several μm can be easily formed, and a photoresist step is not required for patterning, which is advantageous in terms of productivity.

Further, even if this acrylic resin is colored before being applied, it has the advantage that it can be made transparent by performing exposure treatment over the entire surface. Also,
Such a process for making the acrylic resin transparent can be performed not only optically as described above, but also chemically.

The photocurable acrylic resin is
It is preferable that the resin has photosensitivity (absorption peak) on an i-line having a wavelength of 365 nm, an h-line having a wavelength of 405 nm, and a g-line having a wavelength of 436 nm. Thereby, a light beam of a mercury lamp generally used for exposure processing can be used. The photo-curable acrylic resin is preferably a resin having the highest energy among these bright lines, that is, a resin having sensitivity to the i-line having the shortest wavelength. Thereby, the processing accuracy of the contact hole 59 can be improved, and coloring due to the photosensitive agent contained in the acrylic resin can be suppressed to a minimum.

In the exposure treatment of the acrylic resin, ultraviolet rays having a short wavelength from an excimer laser may be used.

As described above, by forming the non-colored interlayer insulating film 77, the light transmittance of the liquid crystal display panel 91 of the present embodiment can be increased. Therefore, high luminance of the liquid crystal display panel can be realized and the amount of light of the backlight can be suppressed, so that low power consumption can be achieved.

In the present embodiment, the thickness of the interlayer insulating film 77 is formed to be larger than the thickness of the interlayer insulating film 17 of the liquid crystal display panel 1 of the prior art, for example, about several μm. Therefore, the light transmittance of the interlayer insulating film 77 is preferably as high as possible. However, since the visibility of the human eye is slightly lower for blue than for green and red, an organic insulating film having a slightly lower transmittance for blue light is selected as the interlayer insulating film 77. It doesn't matter. Thus, when an organic insulating film having a low transmittance of blue light is used,
The deterioration of the display quality of the liquid crystal display panel 91 is small.

In this embodiment, the thickness of the interlayer insulating film 77 except for the spacer 79 and the contact hole 59 is set to about 3.0 μm. However, the present invention is not limited to this. It can be set appropriately according to the dielectric constant. In particular, in order to sufficiently reduce the capacitance, the thickness of the interlayer insulating film 77 is preferably about 1.5 μm or more, and more preferably 2.0 μm or more.

Examples of the acrylic resin having the above-mentioned characteristics include a material obtained by mixing a naphthoquinonediazide-based positive photosensitive agent with a base polymer composed of a copolymer of methacrylic acid and glycidyl methacrylate. Since this acrylic resin contains a glycidyl group,
By heating, it can be cross-linked (cured) and easily brought into a semi-cured state. The physical properties after curing have a dielectric constant of about 3.4 and a value of 400 nm to 800 n.
The transmittance of light in the wavelength range of m is as good as 90% or more.
Furthermore, irradiation with i-ray (wavelength: 365 nm) ultraviolet light has the advantage of being bleached in a short time. This acrylic resin has a heat resistance temperature of about 2
Since it is about 80 ° C., it has relatively high heat resistance. Therefore, after the formation of the interlayer insulating film 77, the temperature is about 250 ° C. to 280 ° C.
Other steps performed at a temperature of not more than about 20 ° C., for example, about 20
During the film forming process of the pixel electrode 52 performed at a temperature of slightly over 0 ° C.,
The interlayer insulating film 77 does not deteriorate. That is, the deterioration of the interlayer insulating film 77 is suppressed while maintaining the characteristics of the third transparent conductive film such as ITO, which becomes the pixel electrode 52.

Further, when the acrylic resin is not decolorized without irradiation with ultraviolet light, the transmittance of transmitted light having a wavelength of 400 nm is about 65%. The transmittance of the transmitted light of 400 nm is 90%.
It is improved to the above. In this decoloring process, the exposure process of ultraviolet rays is performed from the front surface of the substrate, but by performing the exposure process from the back surface in parallel, the decolorization process can be completed in a short time, thereby improving the apparatus throughput. Can contribute.

Although a thermosetting acrylic resin is used in this embodiment, a thermoplastic resin may be used as another embodiment. In this case, the transfer mold 83 is pressed against the thermoplastic resin in a softened state by heating the thermoplastic resin. However, in order to reduce the residual stress, it is preferable that after transferring the uneven portion in a semi-cured state, the resin having the smallest possible curing shrinkage is photocured.

Next, a method of manufacturing a liquid crystal display panel according to a second embodiment of the present invention will be described with reference to FIGS. The method of manufacturing the liquid crystal display panel according to the second embodiment of the present invention is different from the method of manufacturing the liquid crystal display panel according to the first embodiment described above only in the step of forming the spacer 89 and the contact hole 88. It is a different process. Therefore, in this embodiment, only this step will be described, and description of the other steps will be omitted.

FIG. 7 is a view for explaining a method for manufacturing a liquid crystal display panel according to the second embodiment of the present invention, and FIG. 8 is manufactured by the method for manufacturing a liquid crystal display panel according to the second embodiment. FIG. 2 is a diagram showing an active matrix substrate 101. The transparent insulating substrate 67 to which the uncured acrylic resin layer 82 has been supplied is disposed above the transparent insulating substrate 67 while being horizontally moved to one side (in the direction of the arrow 104). -Shaped transfer roller 10 on which is formed
The uneven portion 102 is transferred to the acrylic resin layer 82 by angularly displacing 3 toward one side (in the direction of the arrow 105) around the rotation axis. Thus, the spacer 79 and the contact hole 59 are formed in the acrylic resin layer 82. Thus, the transfer roller 10
By using No. 3, since the concave and convex portions are transferred in a state where the transfer roller 103 and the acrylic resin layer 82 are in point contact, the pressing force can be significantly reduced. Therefore, cracking of the substrate can be prevented.

[0079]

According to the present invention, an organic insulating film is supplied on an active element of a first substrate, and a transfer type having an uneven portion on the surface is used as an organic insulating film in an uncured state. By pressing, the irregularities are transferred to the organic insulating film. by this,
A spacer formed of a convex portion and a contact hole formed of a concave portion are formed in the organic insulating film. Therefore, even if the pressing force is small, the spacer and the contact hole can be reliably formed in the organic insulating film. In addition, since the uneven portion is transferred in an uncured state of the organic insulating film, the resin of the organic insulating film, which is excluded by the transfer-type convex portion, is easily removed. As a result, the amount of resin remaining in the contact hole is reduced as compared with the prior art, and electrical connection between the pixel electrode and the active element is ensured. Furthermore, since the amount of resin flowing into the concave portion of the transfer mold is reduced, the spacer can be reduced, and the aperture ratio is improved.

According to the present invention, after forming a spacer and a contact hole in the organic insulating film by the transfer type, the surface of the organic insulating film is uniformly removed by etching. Therefore, the organic insulating film remaining in the contact hole can be completely removed, and the active element and the pixel electrode are reliably connected.

Further, according to the present invention, the concave-convex portion is transferred to the organic insulating film by angularly displacing the arc-shaped transfer die having the concave-convex portion on the surface around the rotation axis, and is transferred to the organic insulating film. A spacer and a contact hole are formed. That is, since the uneven portion is transferred in a state where the transfer mold and the organic insulating film are in point contact with each other, the pressing force can be significantly reduced.

Further, according to the present invention, since the organic insulating film is made of a photocurable resin, the residual stress is small and the processing accuracy is good as compared with the thermosetting resin. Furthermore, even if the organic insulating film is supplied to a relatively large thickness, the organic insulating film can be cured in a short time, and the production efficiency is good.

Further, according to the present invention, since the acrylic resin has a relatively low relative dielectric constant, even if the pixel electrode and other wiring are overlapped with a large area and overlapped, the pixel electrode and other wiring are not overlapped. Can be reduced. Accordingly, disturbance of a signal input to the pixel electrode can be reduced, and an aperture ratio can be improved while maintaining high display quality.

Further, according to the present invention, the optical transmittance of the organic insulating film is improved by performing the optical decolorizing treatment on the organic insulating film. As a result, a high luminance state can be maintained, and a bright image can be displayed with low power consumption.

Further, according to the present invention, the light transmittance of the organic insulating film is improved by performing the chemical decolorization treatment on the organic insulating film. As a result, a high luminance state can be maintained, and a bright image can be displayed with low power consumption.

According to the present invention, a resin having a photosensitive wavelength peak near 365 nm is used for the organic insulating film. Such a resin does not react to light leakage in the visible light region during the manufacturing process of the liquid crystal display panel. Therefore, the processing accuracy of contact holes and the like can be improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing a configuration of one pixel portion of an active matrix substrate 51 constituting a transmissive liquid crystal display panel according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1;

FIG. 3 is a view showing a state in which a TFT 56 is formed on a transparent insulating substrate 67.

FIG. 4 is a diagram showing a state in which an acrylic resin layer 82 is formed on a transparent insulating substrate 67 on which a TFT 56 is formed.

FIG. 5 is a diagram showing a state immediately before transferring a concave and convex portion 90 to an acrylic resin layer 82 by a transfer die 83;

FIG. 6 is a view showing a state in which a concave and convex portion 90 is transferred to an acrylic resin layer 82;

FIG. 7 is a diagram illustrating a method for manufacturing the liquid crystal display panel according to the second embodiment of the present invention.

FIG. 8 is a diagram illustrating an active matrix substrate 101 manufactured by the method for manufacturing a liquid crystal display panel according to the second embodiment.

FIG. 9 is a diagram showing a general configuration of an active matrix substrate 1 of a transmission type liquid crystal display panel according to the prior art.

FIG. 10 is a sectional view of a TFT3 portion of an active matrix substrate 1 of a TFT type liquid crystal display panel according to the prior art.

FIG. 11 is a diagram showing a prior art disclosed in Japanese Patent Application Laid-Open No. 10-26041.

[Explanation of symbols]

 51, 101 Active matrix substrate 52 Pixel electrode 56 TFT (active element) 59 Contact hole 67 Transparent insulating substrate (first substrate) 79 Spacer 80 Counter substrate (second substrate) 82 Acrylic resin layer (organic insulating film) 83 Transfer Type 91 Liquid crystal display panel 103 Transfer roller

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/28 G02F 1/136 500 5F110 21/768 H01L 21/90 A 29/786 29/78 612D 21 / 336 F term (for reference) 2H089 LA04 LA09 MA04X NA01 QA12 QA13 TA02 TA05 TA09 2H092 JA26 JA46 JB57 JB58 JB64 JB68 KB22 MA01 MA05 MA17 NA07 NA15 NA27 PA03 4M104 AA09 BB36 CC01 DD07 DD15 5C094 AAA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA EB02 HA08 5F033 GG04 HH38 JJ38 KK38 PP15 QQ09 QQ54 QQ99 RR21 SS22 VV15 XX09 XX24 XX33 5F110 CC07 DD02 HK07 HK09 HK21 HK33 HL14 NN02 NN04 NN27 NN72

Claims (8)

[Claims] A first and a second substrate facing each other, a spacer for maintaining a predetermined interval between the first and the second substrates, a liquid crystal layer interposed between the first and the second substrates,
A method of manufacturing a liquid crystal display panel, comprising: a pixel electrode provided on a first substrate for controlling the direction of liquid crystal; and an active element provided on the first substrate for controlling the pixel electrode. Supplying an organic insulating film on the top, a transfer mold having an uneven portion on the surface is opposed to the organic insulating film, and the transfer mold is pressed against the organic insulating film in a state where the organic insulating film is completely uncured or softened. By transferring the concavo-convex portion to the organic insulating film, a spacer formed of a convex portion and a contact hole formed of a concave portion are formed on the organic insulating film, and the spacer and the contact hole are formed on the organic insulating film. A method for manufacturing a liquid crystal display panel, comprising: forming an electrode film serving as a pixel electrode to electrically connect the active element and the pixel electrode via a contact hole. 2. The method for manufacturing a liquid crystal display panel according to claim 1, wherein only a surface portion of said organic insulating film in which said spacer and said contact hole are formed is uniformly removed by etching. 3. The transfer mold is an arc-shaped member having an uneven portion formed on a surface thereof, and transfers the uneven portion to the organic insulating film while angularly displacing the transfer mold around an axis. 3. The method of manufacturing a liquid crystal display panel according to claim 1, wherein 4. The method according to claim 1, wherein the organic insulating film is made of a photocurable resin. 5. The method according to claim 1, wherein the organic insulating film is made of an acrylic resin. 6. The method of manufacturing a liquid crystal display panel according to claim 1, wherein the organic insulating film is optically decolorized. 7. The method for manufacturing a liquid crystal display panel according to claim 1, wherein the organic insulating film is chemically decolorized. 8. The method for manufacturing a liquid crystal display panel according to claim 1, wherein the organic insulating film is made of a resin having a photosensitive wavelength peak near 365 nm.