JP2003050386A - Liquid crystal panel and method for manufacturing liquid crystal panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent display quality from lowering due to abnormal alignment generated by a difference in level of a light shielding layer on a switching element and, at the same time, to ensure the aperture ratio of a panel. SOLUTION: The liquid crystal panel comprises a liquid crystal material 5 held between a substrate provided with a switching element 3, a color filter layer 2 and a transparent electrode film 41 and an opposite substrate provided with a transparent electrode film 4. The difference in level caused by the resin light shielding layer 21 on the switching element 3 is >=1.9 μm and a metal light shielding region 33 to conceal the difference in level is disposed outside the resin light shielding layer 21 with >=4 μm width. Thereby the abnormal alignment is concealed, alignment of the liquid crystal is stabilized and the display quality is improved. Also the aperture ratio of the panel is ensured by placing the metal light shielding region 33 within <=7 μm outside the edge of the resin light shielding layer 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal panel having a switching element, a color filter layer and a transparent electrode film on the same substrate, and a transparent electrode on a counter substrate, and a method for manufacturing the liquid crystal panel.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIG.

In the case of a conventional liquid crystal panel having a structure in which a color filter substrate and an array substrate are bonded together, a liquid crystal material generated by a step due to a wiring pattern (source wiring 31, etc.) on the array substrate or an electric field between the wiring pattern and the pixel electrode 41. In order to conceal the alignment abnormality of No. 5, it was necessary to dispose a light shielding layer (black matrix layer) 21 between each pixel. Further, in consideration of positional misalignment between the array pattern and the color filter pattern formed on both substrates at the time of bonding, it is necessary to design the width of the black matrix layer 21 to be wider than a certain width.

The required line width of the black matrix layer 21 is determined by the alignment accuracy at the time of bonding, regardless of the resolution of the panel. Therefore, as the resolution of the liquid crystal panel is improved and the pixel size is reduced, There is a problem that the area ratio of the black matrix layer 21 becomes large and the panel transmittance becomes small.

In recent years, a color filter layer 2 is formed on an array pattern of switching elements 3 (COA substrate), and a transparent electrode 4 having no pixel pattern is formed on a counter substrate.
A color filter on array configuration (COA configuration) in which only (opposing transparent electrode substrate) is formed has been proposed (see FIGS. 1 and 2 relating to the present invention).

In the case of this COA structure, by forming the color filter layer 2 on the array substrate, it is possible to almost eliminate the influence on the liquid crystal alignment due to the step of the array wiring pattern and the electric field between the pixel electrodes 41. .

Further, by forming the overcoat layer 15 on the color filter layer 2, a step due to the color filter overlapping portion 25 on the substrate and the light shielding layer (black matrix layer) 21 on the switching element 3 is formed. It is possible to flatten and minimize the effect of the step on the liquid crystal alignment.

(The overcoat layer 15 also has an effect of preventing the printing which is caused when impurities are eluted from the color filter layer 2 into the liquid crystal layer and the deterioration of the display quality such as flicker.) Since the transparent electrode 4 has no pixel pattern, the bonding alignment accuracy between both substrates, which required accuracy of ± several μm or less, can be relaxed to about ± 400 μm.

As described above, in the case of the COA structure, it is sufficient to use the array wiring to shield the boundary between pixels, and it is not necessary to specially form the black matrix layer 21.
(The black matrix layer is formed only for shielding the switching element 3 and forming a frame at the time of sealing.) Therefore, it is possible to improve the aperture ratio (panel transmittance) and realize a high-resolution liquid crystal panel. can do.

[0010]

However, in order to meet the increasing demand for reduction in the manufacturing cost of liquid crystal panels in recent years,
It has been proposed to omit the overcoat layer 15 (FIG. 2). When the overcoat layer 15 is omitted, liquid crystal alignment abnormality is likely to occur due to the step due to the color filter overlapping portion 25 on the substrate and the light shielding layer 21 on the switching element 3. In particular, as the color purity of the color filter is improved, the thickness of the color filter layer tends to increase, and when the overcoat layer is omitted, the step due to the resin light shielding layer 21 on the switching element 3 becomes 2 μm or more. There are many cases.

In order to cover this abnormal alignment region, there is a means such as widening the width of the metallic light shielding region 33 under the switching element to shield the abnormal alignment. In this case, the aperture ratio of the panel (panel COA will decrease and COA
There is a problem that it is difficult to obtain the effect of the configuration. For this problem, a design method for minimizing the area of the light-shielding region for shielding the step is required.

Further, even when the overcoat layer 15 is formed as a measure against the elution of impurities from the color filter layer 2, moisture is released from the overcoat layer 15 during heat treatment or vacuum injection after panel assembly. Display defects may occur. In order to minimize the amount of released moisture, it has been attempted to make the overcoat layer 15 as thin as possible, but in this case as well, the smoothness of the substrate surface is improved as in the case of no overcoat. However, there is a problem that the alignment error is likely to occur due to the decrease in level.

Therefore, it is an object of the present invention to prevent the display quality from deteriorating due to the alignment abnormality caused by the step of the light shielding layer on the switching element of the color filter on array panel, and to secure the aperture ratio of the panel. A liquid crystal panel and a method for manufacturing the liquid crystal panel are provided.

[0014]

In order to solve the above-mentioned problems, a liquid crystal panel according to claim 1 of the present invention comprises a substrate provided with a switching element, a color filter layer and a transparent electrode film, and a transparent electrode film facing each other. A liquid crystal panel in which a liquid crystal material is sandwiched between the substrate and a substrate provided therein, and a step generated by the resin light shielding layer on the switching element is 1.9.
A metal light-shielding region having a width of 4 μm or more and hiding this step is provided outside the resin light-shielding layer with a width of 4 μm or more.

If the step difference caused by the resin light-shielding layer on the switching element is less than 1.9 μm, the alignment abnormality does not occur. However, taking the light-shielding effect into consideration, the step difference is generated especially in the case of the overcoatless structure. In many cases, it is difficult to set the thickness to less than 1.9 μm. Therefore, it is effective to conceal the misalignment by providing a metal light-shielding region that hides the step with a width of 4 μm or more outside the resin light-shielding layer. In this case, the alignment of the liquid crystal in the display pixel area can be stabilized and the display quality is improved.

According to a second aspect of the present invention, in the liquid crystal panel according to the first aspect, the metal light-shielding region for hiding a step generated by the resin light-shielding layer is 7 μm or less outside the edge of the resin light-shielding layer. . As described above, since the metal light-shielding region that hides the step generated by the resin light-shielding layer is 7 μm or less from the end of the resin light-shielding layer, the light-shielding region that hides the step can be minimized. Is improved.

Furthermore, in order to minimize the light-shielding region that hides the step, it is effective to determine the width of the light-shielding region in accordance with the alignment direction (rubbing direction) of the liquid crystal molecules. Therefore, in the liquid crystal panel according to claim 3, the metal light-shielding region that hides the step generated by the resin light-shielding layer is a shadow of the step in the direction rubbed by the rubbing cloth during the rubbing process for aligning the liquid crystal molecules. The resin light-shielding layer has a width of 4 μm or more from the end.

As described above, since the metal light-shielding region is provided with a width of 4 μm or more from the end of the resin light-shielding layer on the side behind the step with respect to the direction rubbed by the rubbing cloth during the rubbing process, the step is formed. The light-shielding area to be hidden can be minimized. That is, the occurrence of the alignment abnormality has a correlation with the rubbing direction and is more likely to occur on the back (shadow) side of the step than on the front side of the step. Therefore, it is effective to install the metal light-shielding region on the back side.

According to a fourth aspect of the present invention, in the liquid crystal panel according to the first or third aspect, the metal light-shielding region that hides a step generated by the resin light-shielding layer is rubbed during a rubbing process for aligning liquid crystal molecules. It is 7 μm or less from the end of the resin light-shielding layer to the outside of the step with respect to the direction in which the cloth is rubbed. As described above, since the metal light-shielding region is 7 μm or less outward from the end of the resin light-shielding layer on the side behind the step in the direction rubbed by the rubbing cloth during the rubbing process, the light-shielding region that further hides the step should be provided. It can be kept to a minimum and the aperture ratio is improved.

A liquid crystal panel according to a fifth aspect is the liquid crystal panel according to any one of the first to fourth aspects, in which a resin overcoat layer is not provided on the color filter layer. Thus, since the resin-made overcoat layer is not provided on the color filter layer, the manufacturing cost is reduced, and the alignment abnormality that occurs when the overcoat layer is omitted is concealed and opened by the configuration of claims 1 to 4. The rate can be improved. In addition, water is not released from the overcoat layer to cause a display defect.

A liquid crystal panel according to a sixth aspect is a liquid crystal panel in which a liquid crystal material is sandwiched between a substrate having a switching element, a color filter layer and a transparent electrode film, and a substrate having a transparent electrode film facing each other. The angle formed by the resin light-shielding layer on the switching element with respect to the display area surface is 10 degrees or more, and the metal light-shielding area that hides the step is 4 μm outside the resin light-shielding layer.
It is installed with the above width.

The angle formed by the inclined region of the step formed by the resin light-shielding layer on the switching element with the display region surface is 1
If the angle is 0 degrees or less, no abnormal alignment occurs, but taking the light-shielding effect into consideration, it is often difficult to set the step to 10 degrees or less especially in the case of the overcoatless structure. Therefore, it is effective to conceal the misalignment by providing a metal light-shielding region that hides the step with a width of 4 μm or more outside the resin light-shielding layer. In this case, the alignment of the liquid crystal in the display pixel area can be stabilized and the display quality is improved.

According to a seventh aspect of the present invention, in the liquid crystal panel according to the sixth aspect, the metal light-shielding region for hiding a step generated by the resin light-shielding layer is 7 μm or less outside the end of the resin light-shielding layer. . As described above, since the metal light-shielding region that hides the step generated by the resin light-shielding layer is 7 μm or less from the end of the resin light-shielding layer, the light-shielding region that hides the step can be minimized. Is improved.

Furthermore, in order to minimize the light-shielding region that hides the step, it is effective to determine the width of the light-shielding region in accordance with the alignment direction (rubbing direction) of the liquid crystal molecules. Therefore, in the liquid crystal panel according to claim 8, the metal light-shielding region that hides the step generated by the resin light-shielding layer is a shadow of the step in the direction rubbed by the rubbing cloth during the rubbing process for aligning the liquid crystal molecules. The resin light-shielding layer has a width of 4 μm or more from the end.

As described above, since the metal light-shielding region is provided with a width of 4 μm or more from the end of the resin light-shielding layer on the side behind the step with respect to the direction rubbed by the rubbing cloth during the rubbing process, the step is formed. The light-shielding area to be hidden can be minimized. That is, the occurrence of the alignment abnormality has a correlation with the rubbing direction and is more likely to occur on the back (shadow) side of the step than on the front side of the step. Therefore, it is effective to install the metal light-shielding region on the back side.

According to a ninth aspect of the present invention, in the liquid crystal panel according to the sixth or eighth aspect, the metal light-shielding region for hiding a step generated by the resin light-shielding layer is rubbed during a rubbing process for aligning liquid crystal molecules. It is 7 μm or less from the end of the resin light-shielding layer to the outside of the step with respect to the direction in which the cloth is rubbed.

As described above, since the metal light-shielding region is 7 μm or less outward from the end of the resin light-shielding layer on the side behind the step in the direction rubbed by the rubbing cloth during the rubbing process, the step is further hidden. The light-shielding area can be kept to a minimum and the aperture ratio can be improved.

A liquid crystal panel according to a tenth aspect is the sixth aspect.
In the liquid crystal panel according to any one of 1 to 9, a point having a height of 10% and a point having a height of 90% with respect to the height of the step are provided along the slope from the bottom of the step in the display pixel. The angle formed by the connecting straight line and the surface of the display area is 10 degrees or more.

As described above, the display of a straight line connecting a point having a height of 10% and a point having a height of 90% with respect to the height of the step along the slope from the bottom of the step in the display pixel By defining the angle formed with the surface of the region as a taper angle and setting this to 10 degrees or more, the shape of the surface step can be specified.

The liquid crystal panel according to the eleventh aspect is the sixth aspect.
In the liquid crystal panel according to any one of 1 to 10, the resin overcoat layer is not formed on the color filter layer. As described above, since the resin overcoat layer is not formed on the color filter layer, the manufacturing cost is reduced, and the abnormal alignment caused when the overcoat layer is omitted is concealed and opened by the structure according to claims 6 to 9. The rate can be improved. In addition, water is not released from the overcoat layer to cause a display defect.

According to a twelfth aspect of the present invention, a liquid crystal panel manufacturing method produces the liquid crystal panel according to any one of the first to eleventh aspects. As described above, since the liquid crystal panel according to any one of claims 1 to 11 is produced, the liquid crystal panel having the above-described effects can be manufactured.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION In manufacturing a liquid crystal panel according to an embodiment of the present invention, a color filter layer 2 (see FIG.
Etc.), a twisted nematic liquid crystal panel is created by using color filter substrates having steps of various shapes, and the liquid crystal alignment stability is examined to determine the step shape and the liquid crystal alignment stability, Also, the relationship between the size of the abnormal region and the case where the alignment abnormality occurs was clarified.

Experimental examples for manufacturing the liquid crystal panel of the embodiment are shown in FIG. 3 (a), FIG. 3 (b), FIG. 4, FIG. 5, and FIG.
Will be explained. FIG. 3A is a schematic plan view of the color filter substrate, and FIG. 3B is a sectional view taken along line A of FIG.

Three base glasses (alkali glasses) having a size of 320 × 400 were prepared, and the color filter layer 2 was formed on two of these in the following manner to prepare a color filter substrate (FIG. 3). (A), FIG. 3 (b)).

(1) The formation of the first color filter layer will be described.

First, after washing the two substrates (A, B), an acrylic blue color filter resist is applied by a spin coater, and then 80 by using a clean oven.
After prebaking at 10 ° C. for 10 minutes, proximity exposure using a predetermined mask and development with an aqueous sodium carbonate solution were carried out to form a pattern of the color filter layer 22.

The patterned color filter substrate was left in a clean oven at 220 ° C. for 1 hour to cure the color filter layer 22.

In the step of applying the color filter resist, the finished film thickness of the color filter layer 22 was adjusted by the number of rotations of spin coating so that the film thickness was 2.4 μm.

The mask pattern used at this time is 1
This is for a color filter of a 5-inch XGA liquid crystal panel, and 1024 stripes of 97 μm width are arranged in parallel.

(2) The formation of the second color filter layer will be described.

The second color filter layer 23 was formed in the same manner as the first layer except the alignment of the exposure mask.

In the exposure step, in order to form various steps on the CF substrate, the rotation mask was intentionally rotated about 0.01 degrees clockwise from the first layer pattern for exposure.
Therefore, the positional relationship between the first layer and the second layer overlaps,
There are three areas, a close-fitting area and a distant area.

In this experiment, the relationship between the surface level difference of the color filter substrate and the liquid crystal orientation is investigated. Since the color of the color filter layer does not matter, the same blue resist as that of the first layer is used for simplicity. , Color filter layer 23
The film thickness of each was set to 2.4 μm as in the first layer.

(3) The formation of the third color filter layer will be described.

The formation of the third color filter layer 24 was also performed in the same manner as the first and second layers except for the alignment of the exposure mask.

In the exposure process for the third layer, the exposure was performed by rotating the mask about 0.01 degrees counterclockwise from the pattern for the first layer.

As the resist material, a blue resist is used as in the first and second layers, and the film thickness 24 of the color filter layer is 2.4 μm as in the first and second layers. So that

A transparent electrode (ITO) 4 having a sheet resistance of 20 to 30 Ω is formed on the surface of the glass substrate on which the three layers of blue color filter layers 22, 23 and 24 have been formed as described above by sputtering to form a color film. Filter substrates A and B were created (FIGS. 3 (a) and 3 (b)).

Remaining one piece of raw glass (alkali glass)
In the same manner, by the sputtering process, 20 to 30
A transparent electrode (ITO) 4 of Ω was formed into a film.

Next, as shown in FIG. 4, one of the two color filter substrates A and B prepared as described above and one transparent electrode substrate are bonded together to form a twisted nematic system. A liquid crystal panel was created.

The remaining one color filter substrate B was used as a sample for measuring the surface level difference.

First, after cleaning the color filter substrate and the transparent electrode substrate, alignment film printing, alignment film curing, and rubbing treatment in a predetermined direction 6 were performed.

At this time, a polyimide type material is used as the alignment film material, and the alignment film is cured at 80 ° C. in a clean oven.
After solvent drying for 15 minutes, heat polymerization was performed at 220 ° C. for 1 hour. The thickness of the alignment film was 500 to 800 angstrom. (For simplicity, the alignment film is omitted for simplicity.) Note that 1 angstrom is 1 × 10 ⁻¹⁰ meters.

In the rubbing treatment, rayon cloth is used as the rubbing cloth, and the tip of the hair is 0.3 mm to 0.4 mm.
The measurement was carried out by setting so as to contact the substrate surface by mm.

Next, seal printing was applied to the color filter substrate, and spacer particles were applied to the counter transparent electrode substrate.

At this time, a thermosetting epoxy resin was used as the sealing material, and 2.0% of glass fiber having a fiber diameter of 4.5 μm was mixed in the resin. The spacer particles used were divinylbenzene-based particles having a particle size of 4.5 μm, and the number of sprayed particles was 100 to 150 per 1 mm 2.

After the color filter substrate and the transparent electrode substrate are bonded together, after the seal is cured, the predetermined steps of glass cutting, liquid crystal 5 vacuum injection, and injection port sealing are carried out,
A liquid crystal panel was created.

The seal is cured using a clean oven 1
It was carried out by heating at 50 ° C. for 1 hour.

A rectangular voltage of 1 kHz was applied to these liquid crystal panels for lighting and display, and the alignment stability of the liquid crystals was observed under a microscope. Since the ITO pattern was not formed on the substrates on both sides of this liquid crystal panel, the lighting display was performed by a solid pattern over the entire surface.

The shape (height, taper angle) of the surface step of the color filter substrate B, which was not used for assembling the liquid crystal panel, was measured using a stylus type step gauge.

When the liquid crystal panel thus prepared is used, since the surface step shape (step height, taper angle) of the color filter substrate is continuously changed within the display surface, a stable region or instability of liquid crystal alignment is obtained. The relationship between the region and the surface step shape can be easily observed.

As shown in FIG. 5, the height of the step is 10 from the bottom of the step in the display pixel along the slope.
The angle formed by the straight line connecting the height point h1 of 90% and the point h2 of 90% with the display area surface is defined as the taper angle. If the vertical distance H between h1 and h2 and the horizontal distance L between h1 and h2 are satisfied, the taper angle = tan ⁻¹ (H / L).

The surface step shape examined as described above,
Table 1 shows the relationship of orientation stability.

[0064]

[Table 1]

From Table 1, the following was found. The misalignment occurred as a domain when a voltage was applied. The orientation abnormality is most likely to occur immediately after the voltage is applied, and becomes shorter as the voltage is constantly applied. Table 1 shows the observation results immediately after voltage application.

The definition of the width and the length of the misalignment is shown in FIG. Normally, the display area of one pixel of 15 inch XGA is 20
Since it is about 0 μm, measurement of 200 μm or more is not performed.

(Result 1) The occurrence of alignment abnormality correlates with the rubbing direction 6, and the back side of the step (shadow area: areas A and C in FIG. 3B) is the front side of the step (FIG. 3B). Area a,
D) is more likely to occur. (In this experiment, the orientation abnormality occurred on the back side of the step in each case.) (Result 2) In the area a, if the step height is less than 1.9 μm, the orientation abnormality does not occur.

(Result 3) On the back side of the step with respect to the rubbing direction 6, if the taper angle of inclination is 10 degrees or less, no abnormal alignment occurs.

(Result 4) When an abnormal orientation occurs,
The width was 3 to 4 μm on both sides of the color filter layer overlapping boundary line regardless of the shape of the step (FIG. 3 (b), FIG. 5).

FIG. 6A is a schematic plan view showing the definition of the abnormal alignment region, and FIG. 6B is a sectional view taken along line B of FIG. As shown in FIG. 6, an alignment abnormal region is formed on the superposition boundary line 26 of the color filter layer 2, 8 is the alignment abnormal occurrence width, 81 is the alignment abnormal occurrence width (peak side), and 82 is the alignment abnormal occurrence width (valley side). ), 83 indicates the length of occurrence of abnormal alignment.

From the above results, the step shape has a height of 1.9 μm.
When m or more or the taper angle is 10 degrees or more, it is necessary to make the width of the light shielding region that shields the step region wider than the overlapping boundary line by 4 μm or more in order to conceal the alignment abnormality.

In recent years, studies have been made to use the light-shielding resin BM (black matrix) also as a column spacer. In this case, the maximum taper angle is 60 ° and the step is 6.0 μ.
It is considered to be about m.

In order to maximize the aperture ratio, it is best to set the width of the light-shielding region wider than the overlapping boundary line to 4 μm. However, in consideration of the alignment accuracy of each layer at the time of manufacturing the COA substrate. If it is included, it is necessary to make it wider than 4 μm.

From the above experiment, the relationship between the step, the alignment abnormality, and the abnormal region could be clarified. Although this experiment was performed using the step difference of the overlapping portion of the blue color filter layer, the present invention can be applied to the surface step difference of the substrate such as the resin light shielding layer on the switching element.
Further, if the step shapes are the same, the method can be applied regardless of the color filter forming method, the color, the presence or absence of an overcoat, and the like.

In line with the results of the above experimental example, actually, a 15-inch X color filter on array (COA) structure was used.
It was confirmed that a GATFT twisted nematic liquid crystal panel was produced and that good display quality without alignment abnormality was obtained. Embodiments of the present invention will be described with reference to FIGS. 1 and 7.

First, the color filter on array (CO
A) A mask for patterning the substrate was prepared.

In designing the mask, the positional relationship between the resin light-shielding layer pattern and the array pattern was designed as follows.

(Design 1) In order to conceal the abnormal alignment region, the light shielding region (metal light shielding film 33) for concealing the step due to the resin light shielding layer 21 on the switching element 3 is rubbed by the rubbing cloth during the rubbing process. With respect to the direction (rubbing direction 6), it is set wider on the side behind the step by 4 μm from the edge of the resin light-shielding region (FIG. 1).

(Design 2) Further, in consideration of the pattern forming accuracy, the width of the metal light shielding film 33 is increased by +3 μm.

(Design 3) From the above (Design 1) and (Design 2), the direction in which the light shielding area for covering the step due to the resin light shielding layer 21 on the switching element 3 is rubbed by the rubbing cloth during the rubbing process (rubbing direction) Regarding 6), a total of 7 μm is installed from the end of the resin light-shielding region on the side behind the step (FIG. 7).

The exposure machine used in the pattern formation of the present embodiment was of the proximity system, and the patterning position accuracy was ± 3 μm.

First, a COA substrate is manufactured using the above mask.

First, a 320 × 400 × 0.7t TFT
Two array substrates (Corning 1737) were prepared.

After washing this TFT array substrate, an acrylic red color filter resist was applied by a spin coater. 80 ° C using a clean oven
After 10 minutes of pre-baking, proximity exposure using a predetermined mask and development with an aqueous sodium carbonate solution were carried out to form a pattern of the red color filter layer 2.

After leaving the patterned color filter substrate in a clean oven at 150 ° C. for 1 hour,
Further, the color filter layer 2 was cured by leaving it at 220 ° C. for 1 hour.

In the coating process of the color filter resist, the finished film thickness of the color filter layer 2 is
The rotation speed of spin coating was adjusted to 2.5 μm.

The mask pattern used at this time is 1
This is for a color filter of a 5-inch XGA liquid crystal panel, and 1024 patterns with holes of 6 μmφ are arranged in parallel on a 99 μm wide stripe. This hole serves as a contact hole 32 for conduction between the source / drain pattern of the array and the pixel electrode.

Subsequently, the pattern of the green color filter layer 2 and the pattern of the blue color filter layer 2 were sequentially manufactured by the same procedure.

The final film thickness of the color filter layer at this time was adjusted by the number of rotations of spin coating so that the green layer had a thickness of 2.3 μm and the red layer had a thickness of 2.1 μm.

Further, a resin light-shielding layer (black matrix layer) 21 for forming a frame at the time of shielding the TFT switching element 3 and sealing is formed by using a mask for the light-shielding layer in the same procedure as that for the color filter layers of three colors. did.

The finished film thickness of the resin light-shielding layer 21 at this time was adjusted by the number of rotations of spin coating so as to be 1.7 μm.

An ITO film was formed on the two array substrates with color filters by sputtering, and then an ITO pattern was formed by a photolithography method to form pixel electrodes 41, thus completing a COA substrate.

As the counter substrate, 320 × 400 ×
0.7t glass substrate (Corning 1737 substrate)
Was prepared, and the ITO pattern 4 was formed by sputtering through a mask having a predetermined pattern to prepare a counter transparent electrode substrate.

Next, the two Cs created as described above
One of the OA substrates and a transparent electrode substrate were bonded together to form a twisted nematic type TFT liquid crystal panel.

The remaining one COA substrate was used as a sample for measuring the surface level difference.

First, after cleaning the COA substrate and the transparent electrode substrate, printing of the alignment film, curing of the alignment film, and rubbing treatment in a predetermined direction were performed.

At this time, a polyimide-based material was used as the alignment film material, and the alignment film was cured at 80 ° C. in a clean oven.
After solvent drying for 15 minutes, heat polymerization was performed at 220 ° C. for 1 hour. The thickness of the alignment film was 500 to 800 angstrom.

In the rubbing treatment, a rayon cloth was used as the rubbing cloth, and the tips of the fluff were 0.3 mm to 0.4 mm.
The measurement was carried out by setting so as to contact the substrate surface by mm.

Next, seal printing was applied to the color filter substrate, and conductive paint was applied and spacer particles were applied to the counter transparent electrode substrate.

At this time, a thermosetting epoxy resin was used as the sealing material, and 2.0% of glass fiber having a fiber diameter of 5.5 μm was mixed in the resin. The spacer particles used were divinyl rubenzene-based particles having a particle size of 4.5 μm, and the number of sprayed particles was 100 to 150 per 1 mm 2.

After the color filter substrate and the transparent electrode substrate were bonded together, after the seal was cured, the glass cutting, the liquid crystal 8 vacuum injection, and the injection port sealing were carried out.
A liquid crystal panel was created.

Seal hardening was performed using a clean oven 1
It was carried out by heating at 50 ° C. for 1 hour.

Peripheral circuits were mounted on this liquid crystal panel, and optical components such as a backlight were incorporated to manufacture a twisted nematic type TFT liquid crystal module.

This liquid crystal module was driven and turned on, and it was confirmed that good display quality without occurrence of alignment abnormality was obtained.

Further, CO not used for panel assembly
The substrate A was measured with a stylus type step meter to measure the surface step of the substrate. The results are shown in Table 2.

[0106]

[Table 2]

As shown in Table 2, the step height on the surface of the light shielding layer 21 on the switching element 3 of this COA substrate is 1.7.
μm, taper angle is based on the light shielding layer 2 on the switching element 3.
It was 25.5 degrees in the inclined portion according to 1. Regarding the step height, the liquid crystal alignment examined in the experimental example was obtained in a stable manner, but the taper angle was a shape in which the liquid crystal orientation was not obtained stably. According to the result of real microscope observation,
Although the alignment abnormality was generated in the resin light-shielding layer, all of it could be hidden by the metal light-shielding film 33.

As described above, when the angle (taper angle) formed by the inclined region of the step formed by the resin light shielding layer on the switching element and the display region surface is 10 degrees or more,
It is effective that the metal light-shielding region that hides the step is provided outside the resin light-shielding layer with a width of 4 μm or more and 7 μm or less.

Further, when the step caused by the resin light-shielding layer on the switching element is 1.9 μm or more, the metal light-shielding region for covering this step is 4 μm or more and 7 μm or less outside the resin light-shielding layer. It is effective that they are installed in the width.

Although the resin overcoat layer is not formed on the color filter layer in FIG. 1, an overcoat layer may be formed as shown in FIG.

[0111]

According to the liquid crystal panel of claim 1 of the present invention, the step difference caused by the resin light-shielding layer on the switching element is set to 1.9 μm or more when the height of the step is less than 1.9 μm. This is because no abnormal orientation occurs.
Since the metal light-shielding region that hides the step is provided outside the resin light-shielding layer with a width of 4 μm or more, the abnormal alignment can be hidden. Therefore, it is possible to obtain a liquid crystal panel having a color filter on array configuration in which the liquid crystal orientation is stable and the display quality is good, and the industrial value is great.

According to the present invention, since the metal light-shielding area for hiding the step generated by the resin light-shielding layer is 7 μm or less outside the edge of the resin light-shielding layer, the light-shielding area for hiding the step should be minimized. It is possible to improve the aperture ratio.

According to the present invention, since the metal light-shielding region is provided with a width of 4 μm or more from the end of the resin light-shielding layer on the side behind the step with respect to the direction rubbed by the rubbing cloth during the rubbing process, It is possible to minimize the light-shielding area that hides. That is, the occurrence of the alignment abnormality has a correlation with the rubbing direction and is more likely to occur on the back (shadow) side of the step than on the front side of the step. Therefore, it is effective to install the metal light-shielding region on the back side.

In the fourth aspect, the metal light-shielding region is 7 μm outward from the end of the resin light-shielding layer on the side behind the step in the direction rubbed by the rubbing cloth during the rubbing process.
Since it is as follows, it is possible to further minimize the light-shielding region that hides the step and improve the aperture ratio.

In the fifth aspect, since the resin-made overcoat layer is not provided on the color filter layer, the manufacturing cost is reduced, and the abnormal alignment caused by the overcoat layer is omitted. It can conceal and improve the aperture ratio. In addition, water is not released from the overcoat layer to cause a display defect.

According to the liquid crystal panel of claim 6 of the present invention, the angle formed between the inclined region of the step formed by the resin light-shielding layer on the switching element and the display region surface is 10 degrees or more. This is because in the case of No. 4, there is no occurrence of abnormal alignment, and since the metal light-shielding region that hides this step is provided outside the resin light-shielding layer with a width of 4 μm or more, the alignment abnormality can be hidden. Therefore, it is possible to obtain a liquid crystal panel having a color filter on array configuration in which the liquid crystal orientation is stable and the display quality is good, and the industrial value is great.

According to the present invention, since the metal light-shielding area for hiding the step generated by the resin light-shielding layer is 7 μm or less outside the end of the resin light-shielding layer, the light-shielding area for hiding the step should be minimized. It is possible to improve the aperture ratio.

According to the eighth aspect, since the metal light-shielding region is provided on the side behind the step with respect to the direction of rubbing by the rubbing cloth at the time of rubbing treatment, the width is 4 μm or more from the end of the resin light-shielding layer. The light-shielding area that hides the step can be minimized. That is, the occurrence of the alignment abnormality has a correlation with the rubbing direction and is more likely to occur on the back (shadow) side of the step than on the front side of the step. Therefore, it is effective to install the metal light-shielding region on the back side.

According to a ninth aspect, the metal light-shielding region is 7 μm outward from the end of the resin light-shielding layer on the side behind the step in the direction of rubbing with the rubbing cloth during rubbing.
Since it is as follows, it is possible to further minimize the light-shielding region that hides the step and improve the aperture ratio.

In a tenth aspect, a straight line connecting a point having a height of 10% and a point having a height of 90% with respect to the height of the step along the slope from the bottom of the step in the display pixel, The shape of the surface step can be specified by defining the angle formed with the surface of the display area as a taper angle and setting this to 10 degrees or more.

In the eleventh aspect, since the resin overcoat layer is not formed on the color filter layer, the manufacturing cost is reduced, and the abnormal orientation caused by the overcoat layer is omitted. It can conceal and improve the aperture ratio. In addition, water is not released from the overcoat layer to cause a display defect.

According to the method of manufacturing a liquid crystal panel according to claim 12 of the present invention, since the liquid crystal panel according to any one of claims 1 to 11 is produced, it is possible to manufacture a liquid crystal panel having the above-mentioned effects. You can

[Brief description of drawings]

FIG. 1 is a schematic view showing a liquid crystal panel (without an overcoat) according to an embodiment of the present invention.

FIG. 2 is a schematic view showing a liquid crystal panel (with an overcoat) according to another embodiment of the present invention.

3A is a schematic plan view showing a color filter substrate used in an experimental example of the present invention, and FIG. 3B is a sectional view showing a color filter substrate used in an experimental example of the present invention.

FIG. 4 is a schematic diagram showing a liquid crystal panel used in an experimental example of the present invention.

FIG. 5 is a schematic diagram showing the definition of a tilt taper angle of a step.

FIG. 6A is a schematic plan view showing the definition of an abnormal alignment region. (B) A cross-sectional view showing the definition of an abnormal alignment region

FIG. 7 is a schematic diagram showing an overlap between a resin light shielding layer and a metal light shielding film in the embodiment of the present invention.

FIG. 8 is a schematic view showing a conventional liquid crystal panel.

[Explanation of symbols]

1 glass substrate 2 color filter layer 15 Overcoat layer 21 Black matrix layer 22 Color filter layer (first layer) 23 Color filter layer (second layer) 24 Color filter layer (third layer) 25 Color filter layer overlap 26 Overlapping boundary line of color filter layers 3 switching elements 31 Source wiring 32 contact holes 33 Metal light-shielding film 4 transparent electrodes 41 pixel transparent electrode 5 Liquid crystal layer 6 rubbing direction 7 Display area surface 71 display pixels 8 Alignment error occurrence area width 81 Alignment error occurrence area width (mountain side) 82 Alignment error occurrence area width (valley side) 83 Length of abnormal orientation area

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G09F 9/00 342 G09F 9/00 342Z 9/30 349 9/30 349C 9/35 9/35 F term ( Reference) 2H090 HB08Y JA02 JB02 JD01 LA05 MB01 2H091 FA02Y FA35Y FB02 FB08 FC02 FD12 GA06 LA16 2H092 JA00 JB51 KB23 MA02 NA07 PA02 PA09 5C094 AA06 BA03 BA43 CA19 CA24 DA09 DA13 ED15 GB10 JA08 CC12 BB12A09 JA02 BB12A12

Claims (12)

[Claims] 1. A liquid crystal panel in which a liquid crystal material is sandwiched between a substrate having a switching element, a color filter layer and a transparent electrode film, and a substrate having a transparent electrode film facing each other. The step formed by the resin light-shielding layer is 1.9 μm or more, and a metal light-shielding region that hides the step is formed on the outside of the resin light-shielding layer.
A liquid crystal panel characterized by being installed with a width of at least μm. 2. A metal light-shielding region for hiding a step generated by the resin light-shielding layer is 7 μm outward from the end of the resin light-shielding layer.
The liquid crystal panel according to claim 1, which is less than or equal to m. 3. The resin light-shielding layer is provided on the side where the metal light-shielding region for concealing the step generated by the resin light-shielding layer is behind the step with respect to the direction rubbed by the rubbing cloth during the rubbing treatment for aligning the liquid crystal molecules. The liquid crystal panel according to claim 1, wherein the liquid crystal panel is installed with a width of 4 μm or more from the edge of the. 4. The resin light-shielding layer is provided on the side where the metal light-shielding region for concealing the step generated by the resin light-shielding layer is behind the step with respect to the direction rubbed by the rubbing cloth during the rubbing process for aligning the liquid crystal molecules. 7μ outward from the edge of
The liquid crystal panel according to claim 1 or 3, which has a thickness of m or less. 5. The liquid crystal panel according to claim 1, which does not have a resin overcoat layer on the color filter layer. 6. A liquid crystal panel in which a liquid crystal material is sandwiched between a substrate having a switching element, a color filter layer and a transparent electrode film, and a substrate having a transparent electrode film facing each other, and a resin on the switching element. The angle formed between the inclined region of the step formed by the light-shielding layer and the display region surface is 10
The liquid crystal panel is characterized in that the metal light-shielding region that covers the step is provided outside the resin light-shielding layer with a width of 4 μm or more. 7. A metal light-shielding region for hiding a step generated by the resin light-shielding layer is 7 μm outward from the end of the resin light-shielding layer.
The liquid crystal panel according to claim 6, which has a thickness of m or less. 8. The resin light-shielding layer is provided on the side where the metal light-shielding region for concealing the step generated by the resin light-shielding layer is behind the step with respect to the direction rubbed by the rubbing cloth during the rubbing treatment for aligning the liquid crystal molecules. The liquid crystal panel according to claim 6, wherein the liquid crystal panel is installed with a width of 4 μm or more from the edge of the. 9. The resin light-shielding layer is provided on the side where the metal light-shielding region for concealing the step generated by the resin light-shielding layer is behind the step with respect to the direction rubbed by the rubbing cloth during the rubbing process for aligning the liquid crystal molecules. 7μ outward from the edge of
The liquid crystal panel according to claim 6 or 8, which has a thickness of m or less. 10. A point having a height of 10% with respect to the height of the step along the slope from the bottom of the step in the display pixel, and 9.
The liquid crystal panel according to any one of claims 6 to 9, wherein an angle between a straight line connecting the 0% height points and the display area surface is 10 degrees or more. 11. The liquid crystal panel according to claim 6, wherein a resin overcoat layer is not formed on the color filter layer. 12. A method of manufacturing a liquid crystal panel for producing the liquid crystal panel according to claim 1.