JP4408021B2 - Manufacturing method of display device substrate - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the manufacture how the substrate of the display device.
[0002]
[Prior art]
Conventionally, a display device such as a liquid crystal display device or a plasma display device includes a pair of glass substrates. The glass substrate of the liquid crystal display device is called a TFT substrate and a color filter substrate. The TFT substrate includes a thin film transistor, and the color filter substrate includes a color filter. In the thin film transistor, a metal layer, an insulating layer, or a semiconductor layer is formed on a glass substrate by a sputtering method or a CVD method, a photoresist is applied on each layer, and each layer is formed in a predetermined pattern using a photolithography method. The thin film transistor is formed by repeating such a process.
[0003]
In recent years, as high definition progresses, the area of one pixel decreases, but it is necessary to ensure a sufficient aperture ratio. For this reason, there is a tendency to reduce the width of the bus line and increase the height of the bus line. When the height of the bus line is increased, a step is formed on the surface of the insulating layer covering the bus line, which is not preferable. Therefore, the insulating layer is thickened so that the surface of the insulating layer is flattened.
[0004]
When the insulating layer (protective film) covering the thin film transistor is made of a layer such as silicon nitride by a CVD method, it is not easy to increase the thickness of the insulating layer. Therefore, the insulating layer is made of an organic material layer by spin coating (for example, Patent Document 1). When a layer of organic material is applied by spin coating, a thick insulating layer can be obtained relatively easily. Usually, after forming an insulating layer, a transparent electrode layer is formed on the insulating layer.
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-72222
[Problems to be solved by the invention]
The insulating layer of the organic material needs to have a thickness of about several μm due to a dielectric constant problem. If there is an isolated large pattern structure in the insulating layer of organic material, when the resist is applied by spin coating after that, the isolated large pattern structure becomes a large resistance to the resist flow, and the resist extends on the extended line of the pattern. The spread of is inhibited. For this reason, a radial film thickness unevenness of the resist occurs starting from the pattern. In the photolithographic process for forming the pixel electrode, if there is a variation in the resist film thickness, the pattern of the pixel electrode is delicately affected, and problems such as display unevenness may occur during use. In particular, the advancement of high definition has a problem in that the pattern of the pixel electrode has a complicated structure, and a variation in dimensions of a few μm of the comma immediately leads to display unevenness.
[0007]
Similarly, in a color filter substrate, a pattern may be formed using a photolithographic method by applying a resist on a color filter resin or an overcoat resin. Film thickness unevenness may occur, leading to display defects.
[0008]
An object of the present invention has an object to provide a manufacturing how the substrate of the display device so as to improve the coating unevenness caused by the organic insulating film or the like at the time of resist coating.
[0009]
[Means for Solving the Problems]
The method for manufacturing a substrate of a display device according to the present invention creates a plate member including a plurality of portions corresponding to the substrates of a plurality of display devices each having a display region and a peripheral region, and the plate member is formed in the peripheral region. A pattern restriction region is defined between two lines connecting the center and both ends of one side of the display area and one side of the center side, and an organic material layer is applied to the plate member In the pattern limiting region, the organic material layer is patterned so as to limit the isolated pattern structure of the organic material layer, and a further layer is formed on the organic material layer. A resist material is supplied while being rotated around the center, applied by spin coating, the additional layer is patterned by a photolithography method, and the plate member is divided into substrates of a plurality of display devices.
[0010]
Further, a substrate of a display device according to the reference of the present invention is a substrate of a display device having a display region and a peripheral region, the organic material layer covering the display region and the peripheral region, and the organic material layer A layer of organic material having an isolated pattern structure in the peripheral region and an isolated region on one side of the display region in the peripheral region The area of the pattern structure is smaller than the area of the isolated pattern structure in the region on one side facing the display region.
[0011]
In the above configuration, the pattern restriction region is formed between two lines connecting the center of the plate member and both ends of one side on the center side of the display region in the peripheral region. In this pattern limiting region, the isolated pattern structure of the organic material layer is limited. Therefore, even when a resist such as a photoresist is applied on the organic material layer, even if the organic material layer has an isolated small pattern structure, such an isolated small pattern structure is The resist spreads smoothly. Therefore, it is possible to improve coating unevenness when applying a resist on the organic material layer.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0013]
FIG. 5 is a schematic cross-sectional view showing a liquid crystal display device as an example of the display device. The liquid crystal display device 10 includes a pair of glass substrates 12 and 14 and a liquid crystal 16 inserted between the glass substrates 12 and 14. The glass substrate 12 is a TFT substrate, and includes a thin film transistor (not shown), a pixel electrode 18 and an alignment film 20. The glass substrate 14 is a color filter substrate and includes a black matrix 22 having pixel openings, a color filter 24, a common electrode 26, and an alignment film 28.
[0014]
FIG. 6 is a cross-sectional view showing an example of the TFT substrate 12. The TFT substrate 12 includes a thin film transistor 30. The thin film transistor 30 includes a gate electrode 32, a gate insulating layer 34, a semiconductor layer 36, a channel protective film 38, a drain electrode 40, and a source electrode 42. A gate bus line and a drain bus line are provided in connection with the gate electrode 32 and the drain electrode 40. The thin film transistor 30 is covered with a silicon nitride insulating layer 44 and an organic material insulating layer 46.
[0015]
The organic material insulating layer 46 has a substantially flat surface and is patterned to have pattern structures 48 and 50. The pattern structures 48 and 50 are non-flat portions such as isolated protrusions and recesses on the surface of the insulating layer 46 made of an organic material. The pattern structure 48 is a contact hole, and the pixel electrode 18 is connected to the source electrode 42 through the contact hole 48 (the insulating layer 44 of the silicon nitride film also has a contact hole). The pattern structure 50 will be described later. In FIG. 6, the alignment film 20 of FIG. 5 is omitted.
[0016]
FIG. 1 is a view showing a mother glass for making the substrates 12 and 14 of FIG. The mother glass (plate member) 60 includes a plurality of portions corresponding to the substrates 12 and 14 of the plurality of display devices 10. In the embodiment in which the present invention is applied to the TFT substrate 12, the mother glass 60 includes two portions 60 a corresponding to the two TFT substrates 12. The mother glass 60 is finally cut into two parts 60a along the line 62, so that two TFT substrates 12 are manufactured.
[0017]
Each TFT substrate 12 has a display area 64 and a peripheral area 66. The display area 64 is a part including a large number of pixel electrodes 18 and a large number of thin film transistors 30. The peripheral region 66 is around the display region 64, and is a portion where a terminal connected to the bus line of the display device 10 and connected to the drive circuit, a terminal connected to the test circuit, and the like are formed.
[0018]
FIG. 1 shows a state in which an organic material insulating layer 46 is formed on the silicon nitride insulating layer 44 of FIG. The organic material insulating layer 46 has pattern structures 48 and 50. The pattern structure 48 is a contact hole and is not shown in FIG. 1 because it is much smaller than the pattern structure 50. The pattern structure 50 is, for example, a hole in the insulating layer 46 made of an organic material that opens above the terminals in the peripheral region 66. The pattern structure 50 can also be a protrusion for imparting mechanical strength.
[0019]
In FIG. 1, the center of the mother glass 60 is indicated by O. A pattern restriction region 68 is defined in the peripheral region 66 between two lines connecting the center O of the mother glass 60 and both ends of one side 64 a on the center O side of the display region 64. The pattern restriction region 68 is indicated by hatching in FIG.
[0020]
When patterning the insulating layer 46 of the organic material, the pattern structure 50 (the pattern structure 50 in the pattern restriction area 68 is indicated by 50a) in the pattern restriction area 68 is restricted. For example, the pattern restriction area 68 may not be provided with the pattern structure 50a, or the area of the pattern structure 50a in the pattern restriction area 68 may be an area on the other side of the display area 64 in the peripheral area 66. The area of the pattern structure 50 is made smaller. Preferably, the area of the isolated pattern structure 50 in the pattern limiting region 68 is 30000 μm ² or more. The pattern structures 50 and 50a may be one independent protrusion or recess, or may be a group of a plurality of adjacent protrusions or recesses.
[0021]
FIG. 2 is a diagram for explaining a problem when a resist is applied after the insulating layer 46 of an organic material is formed. The resist is applied by spin coating. In spin coating, a resist material is supplied while rotating the mother glass 60 around the center O in the direction of arrow A. If there is an isolated large pattern structure 50 in the insulating layer 46 of the organic material, the isolated large pattern structure 50 becomes a large resistance to the resist flow, and the spread of the resist on the extended line of the pattern is inhibited. For this reason, a radial film thickness unevenness 70 of the resist occurs from the pattern structure 50 as a starting point. That is, in spin coating, the resist flows radially outward due to centrifugal force. Therefore, if there is a pattern structure 50 in the radial direction in which the resist flows, the resist does not flow smoothly after the pattern structure 50. Therefore, if there is a variation in the resist film thickness, the pattern of the pixel electrode 18 is subtly affected in the formation of the pixel electrode 18, which may cause problems such as display unevenness during use.
[0022]
In the present invention, since the pattern structure 50 (50a) is restricted in the pattern restriction region 68, the resist flow is not hindered at least in the pattern restriction region 68. The pattern restriction region 68 is on a course where the supplied resist flows toward the display region 64, and the resist flow is not obstructed in the pattern restriction region 68, so that the resist flows smoothly in the display region 64. Therefore, the pattern of the pixel electrode 18 in the display area 64 is not affected, and display unevenness does not occur during use.
[0023]
FIG. 3 is a view showing a modification of the mother glass. In the embodiment of FIG. 3, the mother glass 60 includes six portions 60 a corresponding to the six TFT substrates 12. The mother glass 60 is finally cut into six portions 60a along the line 62, so that six TFT substrates 12 are manufactured.
[0024]
FIG. 4 is a view showing a modification of the mother glass. In the embodiment of FIG. 4, the mother glass 60 includes 15 portions 60 a corresponding to 15 TFT substrates 12. The mother glass 60 is finally cut into 15 portions 60a along the line 62, so that 15 TFT substrates 12 are manufactured.
[0025]
3 and 4, each TFT substrate 12 has a display area 64 and a peripheral area 66. The display area 64 is a part including a large number of pixel electrodes 18 and a large number of thin film transistors 30. The organic material insulating layer 46 has pattern structures 48 and 50. The pattern structure 48 is a contact hole and is not shown in FIGS. 3 and 4 because it is much smaller than the pattern structure 50. The pattern structure 50 is an opening of an insulating layer 46 made of an organic material at a position corresponding to a terminal of the peripheral region 66, for example.
[0026]
3 and 4, the pattern restriction region 68 is defined between two lines connecting the center O of the mother glass 60 and both ends of one side 64 a on the center O side of the display region 64 in the peripheral region 66. . The pattern restriction area 68 is indicated by hatching. In patterning the organic material insulating layer 46, the pattern structure 50 is restricted in the pattern restriction region 68. For example, the pattern structure 50 is not provided in the pattern restriction area 68, or the area of the pattern structure 50 in the pattern restriction area 68 is an area on the other side of the display area 64 in the peripheral area 66. The area of the pattern structure 50 is made smaller. Therefore, the operation of the embodiment of FIGS. 3 and 4 is the same as that of the embodiment of FIG. In this way, unlike the conventional pattern formation position, by limiting the pattern formation position, the resist coating is applied to the substrate on which the organic material insulating layer 46 is formed thick and the pixel electrode or the like is formed thereon. Unevenness can be improved.
[0027]
A specific example of the manufacturing method of the TFT substrate 12 of FIGS. 1 and 6 will be further described. A metal film made of Al / MoN / Mo is formed on the mother glass 60, and a gate electrode resist pattern and a Cs electrode resist pattern are formed by a photolithography process. Then, the gate electrode 32, the gate bus line, and the Cs electrode are formed by performing etching and peeling treatment using the resist pattern as a mask.
[0028]
Next, a silicon nitride film, a semiconductor film, and a silicon nitride film are continuously formed, a channel protective film resist pattern is formed by a photolithography process, and etching and stripping processes are performed using the resist pattern as a mask, whereby the gate insulating film 34 is formed. Then, a semiconductor layer 36 and a channel protective film 38 are formed.
[0029]
A Ti / Al / Ti metal film is formed, and a source / drain electrode resist pattern and a signal line resist pattern are formed by a photolithography process. Then, the drain electrode 40, the source electrode 42, and the drain bus line are formed by performing etching and peeling treatment using the resist pattern as a mask.
[0030]
A silicon nitride film is formed. A 4 μm thick acrylic positive organic transparent insulating layer is applied thereon, exposed to light, and developed to form an insulating layer 44 made of a silicon nitride film and an insulating layer 46 made of an organic material. Structures 48 and 50 are formed. At that time, the pattern structure 50 (50a) of the pattern limiting region 68, which is a region connecting the center O of the mother glass 60 and the entire display region 64 in a straight line, is limited. Here, unlike the pattern structure (contact hole) 48 formed in the display region 64, the limited pattern structure 50 (50a) is provided at a position separated from the display region 64 by 1000 μm or more, and is 30000 μm ² or more. The pattern has an area and is not electrically connected to a panel or a pixel and exists uniquely.
[0031]
The pattern structure 50 (50a) as a specifically limited isolated pattern or pattern group is a pattern group in which a pattern that is continuously concentrated within a rectangle 5000 × 2000 μm and two patterns of a rectangle 415 × 80 μm are separated by 250 μm. 2 types in total. As a result, there is no obstacle that hinders the spread of the resist in the display region 64, so that the resist film thickness variation can be prevented and the occurrence of display unevenness can be prevented. After the organic material insulating film 46 is formed, the silicon nitride insulating layer 44 is etched using the organic material insulating film 46 as a mask to complete a contact hole. Next, a transparent electrode film made of ITO is formed, and the pixel electrode 18 is formed by photolithography.
[0032]
FIG. 7 is a cross-sectional view showing another example of the TFT substrate. In this embodiment, the TFT substrate includes a thin film transistor and a color filter. Similar to the example of FIG. 6, the thin film transistor 30 includes a gate electrode 32, a gate insulating layer 34, a semiconductor layer 36, a channel protection film 38, a drain electrode 40, and a source electrode 42.
[0033]
An insulating layer 44 of silicon nitride film is provided so as to cover the thin film transistor 30. On the silicon nitride insulating layer 44, a blue color filter 72B, a red color filter 72R, and a green color filter 72G are provided in association with each thin film transistor 30. Further, an organic material insulating layer 46 is provided so as to cover these color filters 72B, 72R and 72G. The color filters 72B, 72R, and 72G also function as an insulating layer of an organic material.
[0034]
The organic material insulating layer 46 includes the pattern structure 50 (50a) of the pattern limiting region 68 described with reference to FIGS. Therefore, the operation of this example is the same as that of the example described above.
[0035]
A specific example of the manufacturing method of the TFT substrate 12 of FIGS. 1 and 7 will be described. A metal film made of Al / MoN / Mo is formed on the mother glass 60, and a gate electrode resist pattern and a Cs electrode resist pattern are formed by a photolithography process. Then, the gate electrode 32, the gate bus line, and the Cs electrode are formed by performing etching and peeling treatment using the resist pattern as a mask.
[0036]
Next, a silicon nitride film, a semiconductor film, and a silicon nitride film are continuously formed, a channel protective film resist pattern is formed by a photolithography process, and etching and stripping processes are performed using the resist pattern as a mask, whereby the gate insulating film 34 is formed. Then, a semiconductor layer 36 and a channel protective film 38 are formed.
[0037]
A Ti / Al / Ti metal film is formed, and a source / drain electrode resist pattern and a signal line resist pattern are formed by a photolithography process. Then, the drain electrode 40, the source electrode 42, and the drain bus line are formed by performing etching and peeling treatment using the resist pattern as a mask.
[0038]
A silicon nitride film is formed. Next, color filters 72B, 72R, and 72G are sequentially formed. At this time, contact holes are also formed in the pattern of the color filters 72B, 72R, 72G.
[0039]
On top of that, an acrylic positive organic transparent insulating film of 4 μm is applied, exposed and developed to form an insulating layer 46 of an organic material, and pattern structures 48 and 50 of the insulating layer 46 of the organic material are formed. At that time, a contact hole is also formed. And the pattern structure 50 (50a) of the pattern restriction | limiting area | region 68 which is the area | region which connected the center O of the mother glass 60 and the whole display area | region 64 linearly is restrict | limited. Here, unlike the pattern structure (contact hole) 48 formed in the display region 64, the limited pattern structure 50 (50a) is provided at a position separated from the display region 64 by 1000 μm or more, and is connected to the panel or pixel. It is a unique pattern that is not electrically connected.
[0040]
The pattern structure 50 (50a) as a specifically limited isolated pattern or pattern group is a pattern group in which a pattern that is continuously concentrated within a rectangle 5000 × 2000 μm and two patterns of a rectangle 415 × 80 μm are separated by 250 μm. 2 types in total. As a result, there is no obstacle that hinders the spread of the resist in the display region 64, so that the resist film thickness variation can be prevented and the occurrence of display unevenness can be prevented. After forming the organic material insulating film 46, the silicon nitride film insulating layer 44 is etched using the organic material insulating film 46 as a mask to form contact holes. Next, a transparent electrode film made of ITO is formed, and the pixel electrode 18 is formed by photolithography.
[0041]
Next, a specific example of the manufacturing method of the color filter substrate 14 by applying the present invention will be described. A metal film made of Cr is formed on the mother glass 60, and a black matrix resist pattern is formed by a photolithography process. Then, the black matrix 22 (see FIG. 5) is formed by performing etching and peeling treatment using the resist pattern as a mask.
[0042]
Next, the color filters 24R, 24G, and 24B are sequentially formed. The color filters 24R, 24G, and 24B are organic material layers. At that time, the pattern structure of the pattern limiting region 68 that is a region in which the center O of the mother glass 60 and the entire display region 64 are connected in a straight line is limited. Here, unlike the pattern structure (contact hole) formed in the display area 64, the limited pattern structure 50 (50a) is provided at a position separated by 1000 μm or more from the display area 64, and is electrically connected to the panel or pixel. It is a unique pattern that is not connected to each other. By restricting the isolated pattern structure, there is no obstacle to the spread of the resist in the display region, so that the resist film thickness variation can be prevented and the occurrence of display unevenness can be prevented. Thereafter, the common electrode 26 was formed, a resist was applied, and a pattern was formed.
[0043]
The embodiment described above includes the following features.
[0044]
(Appendix 1) Create a plate member including a plurality of portions corresponding to substrates of a plurality of display devices each having a display region and a peripheral region,
Forming a pattern limiting region between two lines connecting the center of the plate member and both ends of one side of the center of the display region in the peripheral region;
Applying a layer of organic material to the plate member;
Patterning the organic material layer to limit the isolated pattern structure of the organic material layer in the pattern limiting region;
Forming a further layer on the layer of organic material;
A method for manufacturing a substrate of a display device, wherein the plate member is divided into a plurality of substrates of the display device. (1)
(Additional remark 2) The manufacturing method of the board | substrate of the display apparatus of Additional remark 1 characterized by there being no isolated pattern structure of the layer of an organic material in this pattern restriction | limiting area | region.
[0045]
(Supplementary Note 3) The area of the isolated pattern structure of the organic material layer in the pattern restriction region is smaller than the area of the isolated pattern structure in the region on the other side of the display region in the peripheral region. A method for manufacturing a substrate of a display device according to appendix 1, wherein: (2)
(Supplementary note 4) The method for manufacturing a substrate of a display device according to supplementary note 3, wherein an area of the isolated pattern structure of the pattern restriction region is 30000 μm ² or more. (3)
(Additional remark 5) The manufacturing method of the board | substrate of the display apparatus of Additional remark 3 characterized by the isolated pattern structure of this pattern restriction | limiting area | region being provided in the position away 1000 micrometers or more from the pixel display area. (4)
(Supplementary note 6) The method for manufacturing a substrate of a display device according to supplementary note 1, wherein the further layer is a transparent electrode layer.
[0046]
(Supplementary note 7) A substrate of a display device having a display area and a peripheral area,
A layer of organic material covering the display region and the peripheral region, and a further layer formed on the layer of organic material,
The organic material layer has an isolated pattern structure in the peripheral region, and the area of the isolated pattern structure in the region on one side of the display region in the peripheral region is the display region in the peripheral region. A substrate of a display device, characterized in that it is smaller than the area of the isolated pattern structure in the region on the other one side. (5)
(Supplementary note 8) The display device substrate according to supplementary note 7, wherein the further layer is a transparent electrode layer.
[0047]
(Supplementary note 9) The substrate of the display device according to supplementary note 7, wherein the substrate is a substrate including a thin film transistor.
[0048]
(Supplementary note 10) The substrate of the display device according to supplementary note 7, wherein the substrate is a substrate including a color filter.
[0049]
(Supplementary note 11) The substrate of the display device according to supplementary note 7, wherein the substrate includes a thin film transistor and a color filter.
[0050]
(Appendix 12) The area of the isolated pattern structure of the organic material layer in the pattern limiting region is equal to the area of the contact hole provided in the organic material layer to connect the pixel electrode to the thin film transistor, but small. The method for manufacturing a substrate of a display device according to appendix 11, wherein:
[0051]
【The invention's effect】
As described above, according to the present invention, even when the organic material layer is formed thick, by limiting the formation position of the organic material layer pattern, the organic material layer can be formed. In the subsequent steps, it is possible to improve the resist unevenness caused by the spin coating of the resist, which can contribute to the improvement of display unevenness.
[Brief description of the drawings]
FIG. 1 is a view showing a mother glass for making the substrate 12 of FIG.
FIG. 2 is a diagram for explaining a problem in applying a resist after forming an insulating layer of an organic material.
FIG. 3 is a view showing a modification of the mother glass.
FIG. 4 is a view showing a modification of the mother glass.
FIG. 5 is a schematic cross-sectional view showing a liquid crystal display device.
FIG. 6 is a cross-sectional view showing an example of a TFT substrate.
FIG. 7 is a cross-sectional view showing another example of a TFT substrate.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display device 12, 14 ... Glass substrate 16 ... Liquid crystal 18 ... Pixel electrode 24 ... Color filter 26 ... Common electrode 30 ... Thin-film transistor 46 ... Insulating layer 48, 50 of organic material ... Pattern structure 60 ... Mother glass 64 ... Display area 66 ... Peripheral area 68 ... Pattern restriction area

Claims (5)

Creating a plate member including a plurality of portions corresponding to substrates of a plurality of display devices each having a display region and a peripheral region;
A pattern limiting region is defined between two lines connecting the center of the plate member and both ends of one side on the center side of the display region in the peripheral region, and one side on the center side,
Applying a layer of organic material to the plate member;
Patterning the organic material layer to limit the isolated pattern structure of the organic material layer in the pattern limiting region ;
Forming a further layer on the layer of organic material;
Coating and cloth spin coating the plate member by supplying a resist material while rotating about its center,
Patterning the further layer by photolithography,
A method for manufacturing a substrate of a display device, wherein the plate member is divided into a plurality of substrates of the display device.   The area of the isolated pattern structure of the organic material layer in the pattern limiting region is smaller than the area of the isolated pattern structure of the organic material layer in the region on the other side of the display region in the peripheral region. The method for manufacturing a substrate of a display device according to claim 1.   3. The method for manufacturing a substrate of a display device according to claim 2, wherein the isolated pattern structure of the pattern limiting region is provided at a position separated from the pixel display region by 1000 μm or more.   2. The method for manufacturing a substrate of a display device according to claim 1, wherein the pattern restriction region does not have an isolated pattern structure of an organic material layer.   2. The method for manufacturing a substrate of a display device according to claim 1, wherein the further layer is a transparent conductive layer.

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