JP2004302298A - Liquid crystal display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a spot defect from being generated by preventing a pixel electrode from being broken throughout a manufacturing stage for a liquid crystal. <P>SOLUTION: A liquid crystal display panel is equipped with a 1st substrate having pixel electrodes which are formed on an organic film and partially include branch shapes, a 2nd substrate which faces the 1st substrate, a liquid crystal layer which is hermetically sealed between the 1st substrate and 2nd substrate, and spacers which are arranged between the 1st substrate and 2nd substrate to keep the thickness of the liquid crystal layer constant, and satisfies a*Pmax/D<0.23, where Pmax is the maximum pressure (N/m<SP>2</SP>) applied to the panel throughout the manufacturing stage for the liquid crystal display panel, D is the scatter density [pieces/m<SP>2</SP>] of spacers, and (a) is the hardness characteristic (μm* pieces/N) of spacers. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a liquid crystal display panel used for a television or a display, and more particularly to a liquid crystal display panel in which damage to a pixel electrode by a spacer is reduced and a method for manufacturing the same.
[0002]
[Prior art]
2. Description of the Related Art A liquid crystal display panel is a display device in which liquid crystal is sealed between two substrates and display is controlled by using the refractive index anisotropy of the liquid crystal. The brightness of the transmitted light of the liquid crystal panel is controlled by changing the direction of the axis of the refractive index anisotropy by applying a voltage to the liquid crystal. In other words, it can be said that the display device converts electrical stimulation into optical switching by utilizing the electro-optical anisotropy of the liquid crystal.
[0003]
In recent years, a method of forming a color filter (CF) on the pixel array side has been proposed for the purpose of facilitating a bonding operation between two glass substrates. When such a structure is adopted, the pixel electrode for applying a voltage to the liquid crystal is formed on an overcoat of resin or the like. That is, the pixel electrode is formed on a relatively soft material. As the pixel electrode, a transparent electrode or a reflective electrode such as a metal is used.
[0004]
FIG. 1 shows a configuration of a CFon array type liquid crystal panel. As shown in FIG. 1A, a color filter 12 is disposed on a TFT substrate 11 having a thin film transistor (TFT) 20, and a pixel electrode 17 is provided on an overcoat resin (organic film) 15 covering the color filter 12. Can be On the other hand, a counter electrode (or a common electrode) 26 is provided on the counter substrate 25. The TFT substrate 15 and the counter substrate 25 sandwich the liquid crystal 19 with the alignment film 18 interposed therebetween. In order to keep the two substrates parallel and keep the thickness of the liquid crystal layer 19 constant, a spacer 21 is inserted. Various proposals have been made for the distribution density of the spacer and the variation with respect to the average particle diameter (for example, see Patent Documents 1 and 2).
[0005]
[Patent Document 1]
JP-A-6-281941
[0006]
[Patent Document 2]
JP 2000-310782 A
[0007]
[Problems to be solved by the invention]
On the other hand, a technique for controlling the alignment of liquid crystal by forming a pixel electrode in a fine pattern has been proposed. For example, as shown in FIG. 1B, a branch-like pixel electrode 17 having a slit 17c can be considered. In the configuration example of FIG. 1B, an active element (thin film transistor) 20 is provided for each pixel 10. Each transistor has a gate electrode 21 and source and drain electrodes 23 and 22. A source electrode 23 of the transistor is connected to an upper pixel electrode 17 via a contact hole 24. The base 17a of the pixel electrode 17 extends from the contact hole 24 along the center of the pixel, and branch electrodes 17b are arranged in a comb-like shape on both sides of the base 17a with a slit 17c interposed therebetween.
[0008]
When a voltage is applied to the pixel electrode 17 by the switching operation of the thin film transistor 20, the liquid crystal molecules on the branch electrode 17b and the slit 17c fall in a direction parallel to the direction in which the branch electrode 17b extends. In the right half branch electrode region and the left half branch electrode region, the direction in which the liquid crystal falls is reversed with respect to the main body 17a. On the backbone 17a, the orientation of the liquid crystal is defined in the direction in which the liquid crystal falls in the left and right branch electrode regions. When the width W of the main body 17a is increased, the direction in which the liquid crystal falls varies, making it difficult to control the liquid crystal alignment. Therefore, the width W of the main portion 17a of the pixel electrode 17 is set to a small value of 0.5 μm to 5 μm.
[0009]
As described above, the hard pixel electrode 17 is formed on the relatively soft overcoat 15 such as an organic film. When the spacer 21 is located on the thin pixel electrode 17 formed on the overcoat, there is a problem that a crack 27 occurs in the pixel electrode 17 depending on the load applied to the substrates 11 and 25. In the worst case, the electrodes may be damaged. As long as the crack or damage occurs at the end of the branch electrode 17b, the effect on the image quality of the liquid crystal display panel is small. However, as shown in FIG. 1B, when the crack 27 or damage occurs in the main body 17a. Then, conduction of the pixel electrode 17 itself is hindered, and the pixel is brought into a state close to a point defect. As a result, the yield is significantly reduced.
[0010]
In the process of manufacturing a liquid crystal display panel, there are several pressing steps. For example, a step of bonding the two substrates 11 and 25, a step of injecting liquid crystal while heating the inside of the cell in a vacuum state, or an end sealing step after injection of liquid crystal. In these steps, various pressures are applied to the substrate. In particular, at the time of edge sealing, a pressure exceeding 4 atm is applied to remove minute bubbles mixed in the liquid crystal.
[0011]
When pressure is applied to the liquid crystal display panel, a load is also applied to each spacer, and an attempt is made to dig into the soft overcoat (organic film) 15. The spacer is also located on the thin hard pixel electrode 17 formed on the organic film 15 in some places. If a load is applied to the pixel electrode 17 via the spacer 21 in a state where the lower organic film is displaced, cracks easily occur in the pixel electrode 17.
[0012]
Accordingly, an object of the present invention is to provide a liquid crystal display panel capable of reducing cracks and disconnections of a pixel electrode, and a method for manufacturing the same.
[0013]
[Means for Solving the Problems]
In order to prevent damage to the pixel electrode, (1) control the spray density of the spacer, (2) control the width of the pixel electrode, and (3) particle size distribution of the spacer in consideration of the hardness characteristics of the spacer used. Is controlled.
[0014]
First, regarding the hardness characteristic of the spacer, when the spacer is softer than the organic film, the organic film is not displaced, so that the pixel electrode is not damaged regardless of the pressure applied to the panel throughout the manufacturing process.
[0015]
Therefore, according to a first aspect of the present invention, a liquid crystal display panel includes a first substrate having a pixel electrode formed on an organic film and at least partially including a branch shape, and a second substrate facing the first substrate. A liquid crystal layer sealed between the first and second substrates; and a spacer disposed between the first and second substrates to maintain a constant thickness of the liquid crystal layer. Is set smaller than the hardness of the organic film.
[0016]
Next, even if the hardness of the spacer is equal to or higher than the hardness of the lower organic film, the pixel electrode is not damaged if the displacement of the organic film caused by the load of the spacer is within a predetermined range.
[0017]
Therefore, according to a second aspect of the present invention, a liquid crystal display panel includes a first substrate having a pixel electrode formed on an organic film and at least partially including a branch shape, and a second substrate facing the first substrate. A liquid crystal display panel comprising: a liquid crystal layer hermetically sealed between the first and second substrates; and a spacer disposed between the first and second substrates to maintain a constant thickness of the liquid crystal layer. Through the manufacturing process, the hardness of the spacer and the organic film is selected such that the displacement of the organic film due to the load applied to the spacer is 0.23 μm or less.
[0018]
Next, when the hardness of the spacer is about the same as or higher than the hardness of the underlying organic film, the pixel electrode is damaged by appropriately setting the spraying density in consideration of the hardness characteristics of the spacer. Can be suppressed.
[0019]
Therefore, according to a third aspect of the present invention, a liquid crystal display panel includes a first substrate having a pixel electrode formed on an organic film and at least partially including a branch shape, and a second substrate facing the first substrate. A liquid crystal layer hermetically sealed between the first and second substrates; and a spacer disposed between the first and second substrates to maintain a constant thickness of the liquid crystal layer. The maximum pressure applied to the panel throughout the panel manufacturing process is defined as Pmax (N / m ² ), The spray density of the spacer is D (pieces / m ² ), Assuming that the hardness characteristic of the spacer is a (μm * piece / N),
a * Pmax / D <0.23
Meet.
[0020]
Preferably, in the liquid crystal display panel having any of the above-described configurations, the electrode width of the branch-shaped portion of the pixel electrode is set to be wider than 5.2 μm and 10 μm or less.
[0021]
In particular, when the pixel electrode is a branch electrode having a main part and a branch electrode extending from the main part, the width of the main part is set to be wider than 5.2 μm and 10 μm or less. When the pixel electrode is composed of a plurality of island-shaped regions and a branch-like connecting portion connecting these, the electrode width of the branch-like connecting portion is set to be wider than 5.2 μm and 10 μm or less. With such a configuration, even when a crack is generated in the pixel electrode due to a load applied to the spacer, it is possible to prevent a disconnection at a main portion or a branch-like connection portion of the pixel electrode. As a result, point defects can be avoided.
[0022]
Next, by controlling the particle size distribution of the spacers in addition to the distribution density of the spacers, damage to the pixel electrodes can be prevented.
[0023]
Therefore, according to a fourth aspect of the present invention, a liquid crystal display panel includes a first substrate having a pixel electrode formed on an organic film and at least partially including a branch shape, and a second substrate facing the first substrate. A liquid crystal layer sealed between the first substrate and the second substrate; and a spacer disposed between the first substrate and the second substrate to maintain a constant thickness of the liquid crystal layer. The standard deviation of the diameter distribution is set within 5%.
[0024]
Preferably, the particle size distribution of the spacer ranges from 0.25% to 5%. When a spacer having a particle size center of 4 μm is used, the variation in the particle size is in the range of 0.1 μm to 0.2 μm.
[0025]
At this time, the dispersion density of the spacer is 100 pieces / 200 pieces / mm. ² Desirably.
[0026]
As described above, by controlling the particle size distribution of the spacer, the occurrence of point defects can be effectively prevented.
[0027]
Other features and advantages of the present invention will become more apparent from the description below with reference to the drawings.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
In a liquid crystal display panel, when a branch-shaped pixel electrode is formed on an overcoat made of resin or the like, damage to the pixel electrode starts when the displacement of the organic film exceeds 0.23 μm due to a load on a spacer portion. I know that.
[0029]
When the spacer is softer than the organic film, the organic film hardly displaces, so that no crack occurs in the pixel electrode. When the spacer has the same or higher hardness as the organic film, even if a load is applied to the pixel electrode on the organic film via the spacer, no crack is generated unless the displacement of the organic film exceeds 0.23 μm. it is conceivable that.
[0030]
Therefore, using two types of spacers A and B, the relationship between the load applied to the spacers and the displacement of the organic film was examined. The specifications of the spacers A and B are as follows.
[0031]
Spacer A is Sekisui Fine Chemical Co., Ltd. Micropearl sp. It is produced by a suspension polymerization method. A divinylbenzene monomer oil droplet having a target particle size is formed and polymerized. The spacer diameter is 4.25 μm. The hardness is 0.6 mN when the spacer is placed on a rigid plate and the displacement is 10% when the spacer is compressed.
[0032]
Spacer B is Sekisui Fine Chemical Co., Ltd. Micropearl TK. It is produced by a seed polymerization method. The core styrene polymer particles are synthesized, and divinylbenzene is polymerized around the styrene polymer particles. The spacer diameter is 4.25 μm. The hardness is 0.4 mN when the spacer is disposed on a rigid plate and the displacement is 10% when the spacer is compressed.
[0033]
FIG. 2 is a graph showing hardness characteristics of spacers A and B. From FIG. 2A and FIG. 2B, 0.6 mN and 0.4 mN are obtained as the compression force when the compression ratio becomes 10%, respectively. This means that the spacer B is softer than the spacer A.
[0034]
FIGS. 3 and 4 are graphs showing the relationship between the load and the displacement of the organic film using the two types of spacers A and B. FIG. The liquid crystal display panel used in the experiment had a branch-shaped pixel electrode with slits on an acrylic resin overcoat, and the pixel electrode width was 4.5 μm. The dispersion density of the acrylic spacers A and B is about 10000000 (100 × 10 ⁶ ) Pcs / m ² And the spacer diameter is 4.25 μm.
[0035]
When the load applied to the spacer was increased, the spacer was immersed in the acrylic resin by about 0.23 μm when a crack occurred in the pixel electrode, regardless of which of the spacers A and B was used.
[0036]
As is clear from FIGS. 3 and 4, when the spacer A is used, the organic film starts to be deformed at the same time as the load is applied, whereas when the spacer B is used, the organic film is deformed until a certain load is applied. Does not happen.
[0037]
The rate of displacement of the organic film due to the load on the spacer is represented by the slope “a” in the graph. The value of “a” is set as a hardness characteristic coefficient of the spacer, which is different from the above-described compression force. The hardness characteristic coefficient a is 90 μm / N for the spacer A and 73 μm / N for the spacer B.
[0038]
When a crack occurs (that is, when the organic film is displaced by 0.23 μm), the load applied to each spacer A is 2.6 mN, but for the spacer B, it is 4.3 mN. Spray density of spacers A and B is 1 × 10 ⁸ Pieces / m ² Then, when the crack occurs, the pressure applied to the liquid crystal panel is 2.6 × 10 ⁵ N / m ² It is. On the other hand, when the spacer B is used, about 4.3 × 10 ⁵ N / m ² No cracks occur until the pressure of 1 is applied to the liquid crystal panel.
[0039]
Conversely, in consideration of the maximum pressure applied throughout the entire manufacturing process, it is possible to determine the spacer-dispersing density without cracking or the spacer hardness without cracking.
[0040]
That is, the displacement of the organic film is Y μm, and the pressure applied to the panel during the production of the liquid crystal display panel is P (N / m ² ), The spacer spray density is D (pcs / m ² ), Assuming that the hardness characteristic coefficient of the spacer is a, Y is
Y ≒ a * P / D (1)
Therefore, the hardness characteristic coefficient a and the scatter density D of the spacer may be determined so that Y is less than 0.23 μm. The maximum pressure Pmax applied in the manufacturing process is substituted for the pressure P. Therefore,
a * Pmax / D <0.23 (2)
A and D (spacer distribution density) may be selected so that
[0041]
Even if the same pressure is applied to the liquid crystal display panel, the load applied to one spacer can be changed by adjusting the distribution density of the spacer. For example, at the time of sealing after liquid crystal injection in the manufacturing process, the liquid crystal display panel is exposed to 4 atm (about 4.04 × 10 4 atm). ⁵ N / m ² ). When the spacer A is used, the spray density (D) is increased to about 1.3 times that of the case where the spacer B is used. Panels can be manufactured.
[0042]
Next, with reference to FIGS. 5 and 6, the relationship between the load applied to the spacer and the generated crack length will be examined. FIG. 5 is a graph showing a crack length generated in the pixel electrode when a load is applied to the spacer A, and FIG. 6 is a graph showing a crack length generated in the pixel electrode when a weight is applied to the spacer B. The crack length referred to here is the length of the crack extending in one direction from the contact point between the spacer and the pixel electrode.
[0043]
When a first-order (linear) equation is approximated based on the value of the crack length C measured at the sample point, when the spacer A is used and when the spacer B is used, the equations are expressed by Expressions (3) and (4), respectively. It is.
[0044]
C _A = 553 * P / D + 1.10 (3)
C _B = 665 * P / D-0.37 (4)
When a crack first occurs, that is, when a load of 2.6 mN is applied to the spacer A, and when a load of 4.3 mN is applied to the spacer B, the crack length is about 2.6 μm. It is.
[0045]
Therefore, if the spacer is located at the center of the pixel electrode and cracks are formed on both sides (opposite direction) from the contact point between the spacer and the pixel electrode, the maximum crack length is 5.2 μm.
[0046]
Therefore, as shown in FIG. 7, the width of the pixel electrode 17 connected to the thin film transistor 20 in each pixel 10, in particular, the width W1 of the main part 17a is set wider than 5.2 μm. By setting such an electrode width, disconnection can be avoided even if a crack occurs in the branch-like pixel electrode 17. If the width W1 of the main portion 17a is set to be larger than 5.2 μm, the width W2 of the branch electrode 17b may be 5.2 μm or less.
[0047]
FIG. 8 is a diagram showing another configuration example of the pixel electrode to which the present invention is applied. The pixel 30 has a thin film transistor 20 and a pixel electrode 37 connected to the thin film transistor 20. The pixel electrode 39 includes a plurality of island-shaped regions 37a, 37b, and 37c, a branch-like connecting portion 37e that connects these island-shaped regions 37a to 37c with each other, and a branch along the contour of the island-shaped regions 37a to 37c. It includes a branch electrode 37d protruding in a shape. In this configuration, if a disconnection occurs in any of the thin branch-like connecting portions 37e, the potential is not transmitted from there to the island-like region, resulting in a point defect.
[0048]
Therefore, the electrode width of the branch-like connecting portion 37e is set to be wider than 5.2 μm and 10 μm or less. This makes it possible to control the alignment of the liquid crystal and prevent disconnection.
[0049]
In the pixel configuration of FIG. 8, an auxiliary capacitance is formed by the auxiliary capacitance electrode 31 and the intermediate electrode 32 to ensure the application of the potential to the pixel electrode 37 including the branch electrode shapes 37 e and 37 d.
[0050]
Next, the dispersion of the particle diameter of the spacer will be examined. As described above, when a displacement exceeding 0.23 μm occurs in the organic film below the pixel electrode due to the load on the spacer portion, cracks start to occur in the branch-shaped pixel electrode. When a crack occurs, the load applied to each spacer depends on the hardness of the spacer. When the spacer A is used, a load of 2.6 mN is applied, and when the spacer B is used, a load of 4.3 mN is applied. Cracks begin to form.
[0051]
Regarding the arrangement of such spacers, not only the distribution density D described above, but also the distribution (standard deviation) of the particle diameter becomes important. If a spacer group having a particle diameter distribution center of 4 μm and a standard deviation of 0.25 μm is scattered, spacers having a particle diameter of 3.25 μm to 4.75 μm in 3σ exist in the panel. When pressure is applied to a liquid crystal display panel in which the distance between the two substrates is 4 μm, the spacer having a particle diameter larger than the gap is formed in an area where the pixel electrode does not exist (for example, a slit portion between the branch electrodes). And the displacement of the organic film causes cracks in the pixel electrodes.
[0052]
Therefore, it is necessary to suppress the damage to the pixel electrode by reducing the particle size distribution of the spacer.
[0053]
FIG. 9 is a table in which, for spacers of the same type as the above-described spacer A, when a group of spacers having different standard deviations is used, the number of spacers subjected to a load of 2.6 mN or more is calculated. With respect to the hardness of the spacer A, when the load applied to each spacer becomes 2.6 mN, cracks begin to occur in the pixel electrode. Therefore, it is desirable that the number of such spacers is small. The liquid crystal display panel used was a 17-inch wide panel having a gap of 4 μm, and the standard deviation was 0.1 μm, 0.15 μm, 0.2 μm, and 0.25 μm for the particle diameter center of 4 μm, respectively. is there. Further, in each spacer group, the number of spacers to which a load of 2.6 mN or more is applied is obtained by changing the distribution density of the spacers.
[0054]
FIG. 10 is a graph showing the relationship between the spacer distribution density and the number of spacers loaded with a load of 2.6 mN or more for each standard deviation based on the table of FIG. FIG. 10B is an enlarged view of an area where the number of graphs in FIG. 10A is low.
[0055]
As is clear from the graph of FIG. 10, when the spacer scatter density is 100 or more, the load applied to each of the spacers with respect to the applied pressure decreases, so that the number of spacers to which the load of 2.6 mN or more is applied is also small. If the standard deviation is within 0.2 μm (within 5%), the application density is 200 / mm. ² In this case, the number of spacers to which a load of 2.6 mN or more is applied can be sufficiently reduced. When the standard deviation is within 0.15 μm (within 3.75%), the application density is 120 particles / mm. ² There is hardly any spacer that applies a load of 2.6 mN or more.
[0056]
On the other hand, when the standard deviation is increased to 0.25 μm, the spacer density becomes 90 to 200 pieces / mm. ² In the range, the number of spacers to which a load of 2.6 mN or more is applied increases. For example, as shown in the table of FIG. ² , A load of 2.6 mN is applied to 18,000 spacers on a 17-inch panel. Since the ratio of the trunk portion of the branch electrode to the pixel is about 1/20, about 900 point defects are stochastically generated.
[0057]
Therefore, for example, a spacer group having a standard deviation of 0.15 μm is set to 200 spacers / mm ² When the spraying is performed at a spraying density of, even if a pressure of 5 atm is applied during the manufacturing process of the liquid crystal display panel, cracking and breakage of the pixel electrode hardly occurs.
[0058]
As described above, in a liquid crystal display panel having a branch-shaped pixel electrode on an organic film, the pixel electrode can be prevented from being damaged by setting the standard deviation of the particle diameter of the spacer to 0.5% or less. When the standard deviation of the spacer particle diameter is set in this range, even if the dispersion density of the spacer is about 100 to 200, it can sufficiently withstand various pressing steps in the manufacturing process.
[0059]
FIG. 11 is a diagram showing an application example of the present invention. FIG. 11A shows a sectional structure of a CFon array type liquid crystal display panel, and FIG. 11B shows a sectional structure of a liquid crystal display panel provided with a color filter on a counter substrate side. In any case, the thin film transistor 20 is provided on the TFT substrate 11. In the configuration of FIG. 11A, the pixel electrode 17 is formed on the overcoat 35 that covers the color filter 12, and in the configuration of FIG. 11B, the pixel electrode 17 is formed on the insulating resin film 45 that covers the thin film transistor 20. Is done.
[0060]
On the other hand, a counter electrode (common electrode) 26 is provided on the counter substrate 25. In the example of FIG. 11B, a counter electrode 26 is provided on the color filter 12 provided on the counter substrate 25 side. Although not shown, an overcoat resin layer may be inserted between the color filter 12 and the counter electrode 26.
[0061]
Liquid crystal 19 is filled between the TFT substrate 11 and the counter substrate 25 via the alignment film 18, and the thickness of the liquid crystal layer 19 is kept constant by the spacer 41. The number of spacers 41 is, for example, 100 to 200 / mm. ² However, the dispersion density can be adjusted in accordance with the hardness characteristics of the spacer 41.
[0062]
For example, when the spacer 41 formed of a material softer than the organic film (including the overcoat resin or the insulating resin) 35 or 45 is used, the pixel electrode may be damaged even if the number of spacers is set to an arbitrary range. And the thickness of the liquid crystal layer can be kept uniform.
[0063]
Alternatively, in the case of using the spacer 41 having a hardness characteristic substantially equal to or higher than the hardness of the organic films 35 and 45, the dispersion density D of the spacer (pieces / m ² )
a * Pmax / D <0.23 (2)
Is set within the range that satisfies. Here, Pmax (N / m ² ) Is the maximum pressure applied to the panel during the process of manufacturing the liquid crystal display panel, and a (μm / N) is the hardness characteristic of the spacer.
[0064]
The particle size distribution (standard deviation) of the spacers 41 is within 5%, preferably in the range of 2.5% to 5%. For example, when the distribution center of the particle size of the spacer 41 is 4 μm, the standard deviation is in the range of 0.1 μm to 0.2 μm.
[0065]
As an example, the number of spacers 41 having a particle size center of 4 μm and a particle size distribution of 0.15 μm is 120 / m ² With a dispersion density of In this case, the number of spacers that apply a load of more than 2.6 mN per one is about 18 in all the panels. In one pixel, the ratio of the area occupied by the backbone 17a (see FIG. 1B) in which the disconnection of the pixel electrode is a problem is 1/20, so that about one point defect occurs in the entire panel. Further, in the pixel electrode 37 having the shape shown in FIG. 8, since the area ratio occupied by the branch-like connecting portions 37e in which disconnection is a problem is further reduced, the occurrence of point defects is almost zero in the whole panel. In this way, by defining the particle size distribution (standard deviation) in addition to the dispersion density of the spacer, the generation of point defects can be effectively suppressed.
[0066]
Finally, with regard to the above description, the following supplementary notes are disclosed.
(Supplementary Note 1) A first substrate having a pixel electrode formed on an organic film and including a branch shape at least partially,
A second substrate facing the first substrate;
A liquid crystal layer sealed between the first substrate and the second substrate;
A spacer disposed between the first substrate and the second substrate to maintain a constant thickness of the liquid crystal layer;
Wherein the hardness of the spacer is smaller than the hardness of the organic film.
(Supplementary Note 2) A first substrate having a pixel electrode formed on the organic film and including at least a part thereof having a branch shape,
A second substrate facing the first substrate;
A liquid crystal layer sealed between the first substrate and the second substrate;
A spacer disposed between the first substrate and the second substrate to maintain a constant thickness of the liquid crystal layer;
And a displacement of the organic film due to a load applied to the spacer is 0.23 μm or less.
(Supplementary Note 3) A first substrate having a pixel electrode formed on the organic film and including at least a part thereof having a branch shape,
A second substrate facing the first substrate;
A liquid crystal layer sealed between the first substrate and the second substrate;
A spacer disposed between the first substrate and the second substrate to maintain a constant thickness of the liquid crystal layer;
And the maximum pressure applied to the panel during the manufacturing process of the liquid crystal display panel is defined as Pmax (N / m ² ), The spray density of the spacer is D (pieces / m ² ), Assuming that the hardness characteristic of the spacer is a (μm * piece / N),
a * Pmax / D <0.23
A liquid crystal display panel characterized by satisfying the following.
(Supplementary Note 4) The liquid crystal display panel according to any one of Supplementary notes 1 to 3, wherein an electrode width in a branch shape of the pixel electrode is wider than 5.2 µm and equal to or smaller than 10 µm.
(Supplementary Note 5) Hardness characteristics and dispersion density of the spacer
a * 4.3 × 10 ⁵ [N / m ² ] / D <0.23
4. The liquid crystal display panel according to supplementary note 3, wherein the liquid crystal display panel is set to satisfy the following.
(Supplementary Note 6) The hardness characteristics and dispersion density of the spacer
a * 2.6 × 10 ⁵ [N / m ² ] / D <0.23
4. The liquid crystal display panel according to supplementary note 3, wherein the liquid crystal display panel is set to satisfy the following.
(Supplementary Note 7) A first substrate having a pixel electrode formed on the organic film and including at least a part thereof having a branch shape,
A second substrate facing the first substrate;
A liquid crystal layer sealed between the first substrate and the second substrate;
A spacer disposed between the first substrate and the second substrate to maintain a constant thickness of the liquid crystal layer;
And the pressure applied to the panel during the production of the liquid crystal display panel is P (N / m ² ), The spray density of the spacer is D (pieces / m ² ), The crack length C generated in the pixel electrode is represented by C = p * P / D + q, and the electrode width W (μm) in the branch shape of the pixel electrode is
W> 2 × (p * P / D + q)
A liquid crystal display panel characterized by satisfying the following.
(Supplementary Note 8) A first substrate formed on the organic film and having a pixel electrode including a branch shape at least partially,
A second substrate facing the first substrate;
A liquid crystal layer sealed between the first substrate and the second substrate;
A spacer disposed between the first substrate and the second substrate to maintain a constant thickness of the liquid crystal layer;
And a standard deviation of the particle size distribution of the spacer is within 5%.
(Supplementary Note 9) The liquid crystal display panel according to supplementary note 8, wherein a standard deviation of a particle size distribution of the spacer is more than 2.5%.
(Supplementary Note 10) The dispersion density of the spacer is 100 to 200 pieces / mm. ² 9. The liquid crystal display panel according to supplementary note 8, wherein
[0067]
【The invention's effect】
Even when a pixel electrode having a branch shape suitable for controlling the alignment of liquid crystal is used in a liquid crystal display panel, breakage of the pixel electrode can be effectively prevented throughout the manufacturing process, and generation of a point defect can be prevented.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a problem of a conventional liquid crystal display panel.
FIG. 2 is a graph showing hardness characteristics of two types of spacers used in a liquid crystal display panel.
FIG. 3 is a graph showing a relationship between a load applied to a spacer A shown in FIG. 2 and a displacement of an organic film.
FIG. 4 is a graph showing a relationship between a load applied to a spacer B shown in FIG. 2 and a displacement of an organic film.
FIG. 5 is a graph showing a relationship between a load applied to a spacer A shown in FIG. 2 and a crack length of a pixel electrode.
FIG. 6 is a graph showing a relationship between a load applied to a spacer B shown in FIG. 2 and a crack length of a pixel electrode.
FIG. 7 is a diagram showing an electrode width of a branch pixel electrode set based on one embodiment of the present invention.
FIG. 8 is a diagram showing a configuration of a pixel electrode according to another embodiment of the present invention.
FIG. 9 is a table in which the number of spacers to which a predetermined load is applied per one piece is obtained by changing the particle size distribution and the spray density of the spacer.
FIG. 10 is a graph showing, for each standard deviation, the relationship between the application density and the number of spacers to which a predetermined load is applied, based on the table of FIG.
FIG. 11 is a diagram showing a configuration example of a liquid crystal display panel to which the present invention is applied.
[Explanation of symbols]
10, 30 pixels
11 TFT substrate
12 Color filters
15, 35, 45 Organic film (overcoat)
17, 37 pixel electrode
18 Alignment film
19 LCD
21, 41 spacer
20 Thin film transistor
21 Gate electrode
22 Drain electrode
23 Source electrode
24 contacts
25 Counter substrate
26 Counter electrode
27 Crack
31 Auxiliary capacitance electrode
32 Intermediate electrode
37a, 37b, 37c Pixel electrode island region
37d branch electrode
37e Branch connection of pixel electrode

Claims (5)

A first substrate having a pixel electrode formed on the organic film and including a branch shape at least in part;
A second substrate facing the first substrate;
A liquid crystal layer sealed between the first substrate and the second substrate;
A spacer disposed between the first substrate and the second substrate to maintain a constant thickness of the liquid crystal layer, wherein a hardness of the spacer is smaller than a hardness of the organic film. Display panel. A first substrate having a pixel electrode formed on the organic film and including a branch shape at least in part;
A second substrate facing the first substrate;
A liquid crystal layer sealed between the first substrate and the second substrate;
A spacer disposed between the first substrate and the second substrate to maintain a constant thickness of the liquid crystal layer, wherein a displacement of the organic film due to a load applied to the spacer is 0.23 μm or less. Characteristic liquid crystal display panel. A first substrate having including pixel electrodes ramified shape to at least a portion is formed on the organic film,
A second substrate facing the first substrate;
A liquid crystal layer sealed between the first substrate and the second substrate;
A spacer disposed between the first substrate and the second substrate to maintain a constant thickness of the liquid crystal layer, and a maximum pressure applied to the panel during a manufacturing process of the liquid crystal display panel is Pmax ((N / m ² ) When the spray density of the spacer is D (pieces / m ² ) and the hardness characteristic of the spacer is a (μm * pieces / N),
a * Pmax / D <0.23
A liquid crystal display panel characterized by satisfying the following. 4. The liquid crystal display panel according to claim 1, wherein an electrode width of the pixel electrode in a branch shape is wider than 5.2 μm and 10 μm or less. 5. A first substrate having a pixel electrode formed on the organic film and including a branch shape at least in part;
A second substrate facing the first substrate;
A liquid crystal layer sealed between the first substrate and the second substrate;
A spacer disposed between the first substrate and the second substrate to maintain a constant thickness of the liquid crystal layer, wherein a standard deviation of a particle size distribution of the spacer is within 5%. Liquid crystal display panel.

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