JP2007192944A - Liquid crystal display device and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device permitting to raise a yield without occurrence of display unevenness such as tone reversal even if colored layer is polished. <P>SOLUTION: Auxiliary capacitance lines 20 are formed on a glass substrate 14, and hexagonal holes of a plane form are formed in the auxiliary capacitance lines 20 at the portions scheduled to cross signal lines 18 so that the auxiliary capacitance lines 20 are not disconnected. Next, after forming an interlayer insulating film 32, the signal lines 18 are formed and a colored layer 26 is formed thereon, then, the colored layer 26 in the hole forming areas is formed with a base 27 relatively lower than wall parts 34 in the peripheral parts. Since the base 27 is not polished even when the colored layer 26 is polished, spacers 28 are erected on this base 27. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device in which a colored layer is provided on an array substrate and a method for manufacturing the same.

  In the current liquid crystal display device, a liquid crystal layer is sandwiched between two glass substrates having electrodes, and the periphery of the two glass substrates is fixed with an adhesive except for the liquid crystal sealing port. The structure sealed with the sealing material is comprised. A spacer for keeping the distance between the two glass substrates constant is installed on the substrate.

Among these, in a liquid crystal display device for color display, a color filter having an RGB colored layer is formed on one of two glass substrates. For example, in a liquid crystal display device using a color type active matrix driving method, a semiconductor layer made of a thin film transistor (hereinafter simply referred to as TFT) made of a semiconductor such as polysilicon or amorphous silicon, and a pixel electrode connected to the semiconductor layer And an array substrate on which a source electrode and a gate electrode are formed, and a counter electrode disposed opposite to the array substrate, and an RGB colored layer is formed on the array substrate (for example, see Patent Document 1). .
JP 2000-171784 A

  In the liquid crystal display device having a colored layer having a color filter function on the array substrate as described above, both end portions of each color are raised due to shrinkage at the time of curing and the step of the signal line compared to the other portions. . Due to the rise, when black is displayed, light is lost from this portion and the contrast is lowered. Therefore, in order to prevent this decrease in contrast, the raised portion is removed by polishing with an abrasive.

  However, if such a raised portion of the colored layer is removed, there is a problem that display unevenness such as gradation inversion occurs and the yield decreases.

  In view of the above problems, the present invention provides a liquid crystal display device and a method for manufacturing the same, in which display unevenness such as gradation inversion does not occur even when a colored layer is polished, and the yield is improved.

  The invention of claim 1 includes an array substrate, a counter substrate disposed opposite to the array substrate, and a liquid crystal layer disposed between the two substrates, and a plurality of wirings arranged in a matrix on the array substrate. A gate line and a plurality of signal lines, a switching semiconductor layer provided for each pixel at an intersection of the gate line and the signal line, and connected to each of the gate line and the signal line, and the switching semiconductor A pixel electrode connected to the layer, a colored layer having a function of a color filter formed to have a different color for each pixel, and a plurality of auxiliary capacitance lines wired in parallel with the plurality of gate lines. In the liquid crystal display device in which the counter substrate has a counter electrode, the colored layer at the intersection of the signal line and the gate line or the auxiliary capacitance line is relatively lower than the peripheral part, A liquid crystal display device, which comprises forming a projection having a spacer function to the lower color layer.

  According to a sixth aspect of the present invention, there is provided a liquid crystal display comprising: a step of forming an array substrate; a step of forming a counter substrate facing the array substrate; and a step of forming a liquid crystal layer disposed between the substrates. In the manufacturing method of the apparatus, the step of forming the array substrate includes a plurality of gate lines on the insulating substrate, a plurality of auxiliary capacitance lines substantially parallel to the plurality of gate lines, and a plurality of gate lines connected to the gate lines. A first step of forming a switching element; a second step of forming an interlayer insulating film above the gate line and the auxiliary capacitance line; and the gate line and the auxiliary capacitance line above the interlayer insulating film; A third step of forming a plurality of signal lines substantially orthogonal to each other; a fourth step of forming a colored layer on an upper layer of the plurality of signal lines; a fifth step of polishing the colored layer; and an upper layer of the colored layer A sixth step of forming pixel electrodes on the substrate; Forming a projection having a function of a spacer at an intersection of the gate line, the auxiliary capacitance line, and the signal line, and the first step includes the gate line, the auxiliary capacitance line, and the signal line. A method of manufacturing a liquid crystal display device comprising the step of providing a hole at an intersection with a signal line, wherein the seventh step is a step of forming a spacer in the hole provided at the intersection.

  The invention of claim 7 includes a step of forming an array substrate, a step of forming a counter substrate opposite to the array substrate, and a step of forming a liquid crystal layer disposed between the substrates. In the manufacturing method of the device, the step of forming the array substrate includes a first step of forming a plurality of gate lines and a plurality of auxiliary capacitance lines on the insulating substrate substantially in parallel, and the gate lines and the auxiliary capacitance. A second step of forming an interlayer insulating film on the upper layer of the line; a plurality of signal lines on the upper layer of the interlayer insulating film substantially orthogonal to the gate line and the auxiliary capacitance line; and a plurality of switching connected to the gate line A third step of forming an element; a fourth step of forming a colored layer on the plurality of signal lines; a fifth step of polishing the colored layer; and forming a pixel electrode on the colored layer. The sixth step and A seventh step of forming a sensor, wherein the third step includes a step of providing a hole at the intersection of the gate line, the auxiliary capacitance line, and the signal line, and the seventh step A method of manufacturing a liquid crystal display device, characterized by being a step of forming a protrusion having a spacer function in a hole provided at the intersection.

  As a result of investigating the reason why display unevenness such as gradation inversion occurs when the colored layer is polished, the present inventor has revealed that the cause is that the cell gap varies. The inventors have also found that the reason why the cell gap can vary is that the height of the base of the spacer varies due to the polishing of the colored layer.

  Therefore, in the present invention, in order to prevent the fluctuation of the height of the base of the spacer, the colored layer at the intersection of the signal line and the gate line or the auxiliary capacitance line is relatively lower than the peripheral part, By preventing the scraping and allowing the spacer to stand upright on the colored layer thus lowered, the spacer having the same height was always arranged.

  The reason will be described below. In order to prevent the influence of light leakage from the spacer itself, the spacer needs to be installed on a light shielding portion on the array substrate, for example, an auxiliary capacitance line or a gate line. At this time, since the base of the spacer is on the wiring, it is higher than the periphery by an amount corresponding to the thickness of the wiring, and the colored layer formed thereon is also higher than the periphery. If the polishing layer is higher than the periphery, the amount of scraping of the colored layer increases, so when the in-plane distribution of the polishing conditions changes, the height fluctuation after polishing becomes larger than the flat part or the part lower than the periphery. . For this reason, conventionally, the fluctuation of the cell gap has become large.

  Therefore, in the present invention, by making the base of the spacer relatively lower than the surrounding part, the variation in the height of the base of the spacer is reduced even if the polishing condition of the colored layer changes.

  Thereby, even if the raised portion of the colored layer is removed by polishing, gap fluctuation can be prevented, and a liquid crystal display device that is inexpensive and excellent in display performance can be obtained.

(First embodiment)
Hereinafter, a liquid crystal display device 10 according to a first embodiment of the present invention will be described with reference to FIGS.

  The liquid crystal display device of the present embodiment has an array substrate 12 having 640 vertical pixels and 480 × 3 (R, G, B) horizontal pixels.

  In the array substrate 12, 640 gate lines 16 are wired in the horizontal direction of the glass substrate 14, and 480 × 3 signal lines 18 are wired in a matrix so as to be orthogonal to the gate lines 16. In addition, 640 auxiliary capacitance lines 20 are also wired in parallel with the gate lines 16.

  A TFT 22 which is a switching element made of a polysilicon semiconductor is formed in the vicinity of the intersection of the gate line 16 and the signal line 18. A gate line 16 is connected to the gate electrode of the TFT 22, a signal line 18 is connected to the source electrode of the TFT 22, and a pixel electrode 24 is connected to the drain electrode of the TFT 22.

  Colored layers 26R, 26G, and 26B that form color filters (R, G, and B) of different colors are formed for each pixel.

  FIG. 7 is a schematic cross-sectional view of the liquid crystal display device according to this embodiment. A counter substrate is disposed to face the array substrate 12. A liquid crystal layer is sandwiched between the counter substrate and the array substrate 12, and a spacer 28 is formed in a protruding shape on the colored layer 26 in order to maintain this cell gap.

  Hereinafter, a method for manufacturing the array substrate 12 will be described in order.

(2) Manufacturing method of array substrate 12 In the following steps, four array substrates 12 are processed on a large glass substrate.

(2-1) First Step In the first step, 640 gate lines 16 and 640 auxiliary capacitance lines 20 are formed laterally on the glass substrate 14 constituting the large glass substrate. The auxiliary capacitance line 20 is formed with a width of 80 μm, and a hole 30 having a substantially hexagonal planar shape is formed at the intersection with the signal line 18. A part of the auxiliary capacitance line 20 is connected by the hole 30 so as not to be disconnected. The width of the hole 30 is 20 μm. The process of forming the TFT 22 is performed simultaneously with this process and the following processes.

(2-2) Second Step In the second step, an interlayer insulating film 32 is formed on the layer on which the gate line 16 and the auxiliary capacitance line 20 are formed.

(2-3) Third Step In the third step, 480 × 3 signal lines 18 are formed. The width of the signal line 18 is 26 μm, and the overlapping portion with the auxiliary capacitance line 20 has a substantially hexagonal planar shape in the upper layer of the hole 60 as shown in FIG. 2, and is thicker than other signal line 18 portions. It has become.

(2-4) Fourth Step In the fourth step, after the signal line 18 is formed, an ultraviolet curable acrylic resin resist in which a green (G) pigment is dispersed is applied to the entire surface by a spinner, and once reaches 30 Pa. After depressurization, the pressure is returned to normal pressure and heated on a hot plate at 80 ° C. for 3 minutes to remove the solvent. Subsequently, 100 mJ / cm < ² > is irradiated with the wavelength of 365 nm through the photomask which irradiates light to the part which wants to be colored green. Thereafter, development is performed with a 0.05% aqueous solution of KOH containing a surfactant for 30 seconds, and baking is performed at 220 ° C. for 60 minutes to form a green colored layer 26G having a thickness of 3.0 μm in that portion.

(2-5) Fifth Step In the fifth step, a blue colored layer having a thickness of 3.0 μm is used in the same manner as in the fourth step, using an ultraviolet curable acrylic resin resist in which a blue (B) pigment is dispersed. 26B is formed.

(2-6) Sixth Step In the sixth step, a red colored layer having a thickness of 3.0 μm is used in the same manner as in the fourth step, using an ultraviolet curable acrylic resin resist in which a red (R) pigment is dispersed. 26R is formed.

(2-7) Seventh Step In the seventh step, polishing is performed using a polishing pad mainly composed of silica and a foamed urethane resin polishing pad to remove the raised portions of the colored layers 26G, 26B, 26R, and polyvinyl chloride. After scrubbing with an alcohol sponge, megasonic cleaning is performed with pure water, and the array substrate 12 is dried by air knife drying.

(2-8) Eighth Step In the eighth step, an ITO film having a thickness of 150 nm is formed as the transparent pixel electrode 24 by sputtering and patterned into a pixel electrode shape.

(2-9) Ninth Step In the ninth step, a photosensitive carbonless black resin is applied to a thickness of 3.0 μm using a spinner, dried at 90 ° C. for 10 minutes, and then 365 nm using a photomask. After being exposed at an exposure amount of 500 mJ / cm ² at a wavelength of, the film is developed with a 0.05% KOH aqueous solution containing a surfactant for 60 seconds, and a frame portion is formed by baking at 220 ° C. for 60 minutes.

(2-9) Ninth Step In the ninth step, a photosensitive transparent acrylic resin is applied to a thickness of 5.5 μm with a spinner, dried at 90 ° C. for 10 minutes, and at a wavelength of 365 nm using a photomask, 500 mJ The substrate 28 is exposed at / cm ² , developed with 0.05% KOH aqueous solution for 30 seconds, and the spacer 28 is formed on the base 27 by baking at 220 ° C. for 60 minutes. The spacer 28 has a protruding shape as shown in FIG. The spacer 28 has a diameter of 8 μm and stands above the hole 30.

(2-10) Tenth Step In the tenth step, AL-1051 (manufactured by JSR Corporation) is printed as an alignment film material on the array formation surface display region of the array substrate 12 to a thickness of 50 nm, and a rubbing treatment is performed. An alignment film (not shown) is formed.

(2-11) Eleventh Step In the eleventh step, an ITO film is formed as a transparent electrode 36 on the counter substrate by a sputtering method to a thickness of 150 nm, and then the same alignment film material as described above is printed and rubbed. Then, an alignment film is formed.

(2-12) Twelfth Step In the twelfth step, an electrode is printed along the periphery of the alignment film of the array substrate 12 other than the liquid crystal injection port, and a voltage is applied to the transparent electrode 36 of the counter substrate. A dislocation material is formed on the electrode dislocation electrode around the adhesive.

(2-13) Thirteenth Step In the thirteenth step, the counter substrate 13 is arranged so that the alignment films face each other and the respective rubbing directions are 90 degrees, and the adhesive is cured by heating to cure the array substrate 12. And the counter substrate are bonded together. At this time, the cell gap between the array substrate 12 and the counter substrate is determined by the spacer 28.

(2-14) Fourteenth Step In the fourteenth step, the liquid crystal composition 15 is injected from the liquid crystal injection port, and then the liquid crystal injection port is sealed with an ultraviolet curable resin.

(2-15) Fifteenth Step In the fifteenth step, the large glass substrate is divided to form four liquid crystal cells.

(3) Effects of the present embodiment When the spacer 28 is formed on the base 27 of the colored layer 26 as described above, the colored layer 26 that is the base 27 of the spacer 28 is affected by the hole 30 as shown in FIG. Is relatively lower than other colored layer 26 portions. That is, the wall portion 34 is formed on the upper surface of the intersection portion of the colored layer 26 by the hole portion 30. Therefore, even when the colored layer 26 is polished, the polishing portion hits the upper end portion of the wall portion 34, and the base 27 of the colored layer 26 surrounded by the wall 34 is not polished, and has a designed height. It becomes. Therefore, even if the protruding spacers 28 are formed in this portion, there is no variation in the height as in the prior art, and even when the counter substrate is installed, there is no variation in the cell gap, and a good display state Can be maintained.

  Further, the hole 30 may be manufactured only by providing the auxiliary capacitance line 20 and the manufacturing method thereof is easy.

(Second Embodiment)
In the first embodiment, the hole 30 is provided in the storage capacitor line 20. Alternatively, the hole 30 may be provided in the gate line 16 and the spacer 28 may be provided upright at the intersection of the signal line 18 and the gate line 16. Good.

(Third embodiment)
In the first embodiment, the hole 30 is provided in the auxiliary capacitance line 20, but instead, the hole 30 may be provided in the signal line 18 to form a relatively low portion in the colored layer 26. Even in this case, variations in the height of the spacers 28 can be prevented.

(Fourth embodiment)
Although the first embodiment is a liquid crystal display device in a Twisted Nematic display mode, an OCB display mode liquid crystal display device may be used instead.

  For example, the photosensitive acrylic resin in the ninth step is applied to a thickness of 4.6 μm, the eleventh alignment film is printed with a high pretilt angle, and the rubbing direction is from the top of the panel on both the array and the counter substrate side. Parallel rubbing downward. As the liquid crystal material, a liquid crystal material for OCB is injected. Even in this case, variations in the height of the spacers 28 can be prevented.

FIG. 3 is a plan view showing a state in which auxiliary capacitance lines, gate lines, and signal lines are wired in the array substrate according to the embodiment of the present invention. It is an enlarged view of A part in FIG. It is the BB sectional view taken on the line in FIG. It is a top view of an array substrate. It is an enlarged view of the B part in FIG. It is the DD sectional view taken on the line in FIG. It is a schematic sectional drawing of the liquid crystal display device in this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Liquid crystal display device 12 Array substrate 14 Glass substrate 16 Gate line 18 Signal line 20 Auxiliary capacity line 22 TFT
24 pixel electrode 26 colored layer 28 spacer 30 hole 32 interlayer insulating film 34 wall

Claims (7)

An array substrate; a counter substrate disposed opposite to the array substrate; and a liquid crystal layer disposed between the substrates.
In the array substrate,
A plurality of gate lines and a plurality of signal lines wired in a matrix;
A switching semiconductor layer provided for each pixel at an intersection of the gate line and the signal line, and connected to each of the gate line and the signal line;
A pixel electrode connected to the switching semiconductor layer;
A colored layer formed to have a different color for each pixel;
A plurality of auxiliary capacitance lines wired in parallel with the plurality of gate lines;
Have
In the liquid crystal display device in which the counter substrate has a counter electrode,
The colored layer at the intersection of the signal line and the gate line or the auxiliary capacitance line is relatively lower than the peripheral portion, and a protrusion having a spacer function is formed on the lowered colored layer. Liquid crystal display device. The plurality of signal lines are wired above the plurality of gate lines and the plurality of auxiliary capacitance lines,
The colored layer is provided on an upper layer of the plurality of signal lines,
2. The gate line or the auxiliary capacitance line in the intersection portion where the protrusion is formed has a hole, so that the colored layer in the intersection portion is relatively lower than the peripheral portion. The liquid crystal display device described. The plurality of signal lines are wired above the plurality of gate lines and the plurality of auxiliary capacitance lines,
The colored layer is provided on an upper layer of the plurality of signal lines,
The liquid crystal display device according to claim 1, wherein a hole is formed in the signal line at the intersection portion where the protrusion is formed, and the colored layer at the intersection portion is relatively lower than the peripheral portion. The liquid crystal display device according to claim 1, wherein a wall portion is erected around the colored layer at an intersection portion where the protrusion is formed. The liquid crystal display device according to claim 1, wherein the colored layer is formed of R, G, and B colors. A method of manufacturing a liquid crystal display device, comprising: a step of forming an array substrate; a step of forming a counter substrate facing the array substrate; and a step of forming a liquid crystal layer disposed between the substrates. ,
Forming the array substrate comprises:
Forming a plurality of gate lines on the insulating substrate, a plurality of auxiliary capacitance lines substantially parallel to the plurality of gate lines, and a plurality of switching elements connected to the gate lines;
A second step of forming an interlayer insulating film above the gate line and the auxiliary capacitance line;
A third step of forming a plurality of signal lines on the interlayer insulating film so as to be substantially orthogonal to the gate line and the auxiliary capacitance line;
A fourth step of forming a colored layer on an upper layer of the plurality of signal lines;
A fifth step of polishing the colored layer;
A sixth step of forming a pixel electrode on the colored layer;
A seventh step of forming a protrusion having a function of a spacer at an intersection of the gate line and the auxiliary capacitance line and the signal line;
Have
The first step includes a step of providing a hole at the intersection of the gate line and the auxiliary capacitance line and the signal line,
The method of manufacturing a liquid crystal display device, wherein the seventh step is a step of forming a protrusion having a spacer function in a hole provided at the intersection. A method of manufacturing a liquid crystal display device, comprising: a step of forming an array substrate; a step of forming a counter substrate facing the array substrate; and a step of forming a liquid crystal layer disposed between the substrates. ,
Forming the array substrate comprises:
A first step of forming a plurality of gate lines and a plurality of auxiliary capacitance lines substantially in parallel on an insulating substrate;
A second step of forming an interlayer insulating film above the gate line and the auxiliary capacitance line;
A third step of forming a plurality of signal lines and a plurality of switching elements connected to the gate lines on the interlayer insulating film substantially orthogonal to the gate lines and the auxiliary capacitance lines;
A fourth step of forming a colored layer on an upper layer of the plurality of signal lines;
A fifth step of polishing the colored layer;
A sixth step of forming a pixel electrode on the colored layer;
A seventh step of forming a protrusion having a spacer function at the intersection portion;
Have
The third step includes a step of providing a hole at the intersection of the gate line and the auxiliary capacitance line and the signal line;
The method of manufacturing a liquid crystal display device, wherein the seventh step is a step of forming a protrusion having a spacer function in a hole provided at the intersection.

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