JP5595678B2 - Liquid crystal display - Google Patents

Description

  The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device in which a color filter is provided on a so-called TFT substrate side.

  A liquid crystal display device (panel) is configured so that a pair of substrates opposed to each other with a liquid crystal interposed therebetween is used as an envelope, and the light transmittance of the liquid crystal is independently controlled in each pixel. For this reason, each of a plurality of pixels serving as unit pixels for color display is provided with color filters having different colors, and these color filters are formed on the liquid crystal side surface of the substrate constituting the envelope.

  Here, one of the pair of substrates constituting the envelope of the liquid crystal display device (sometimes referred to as a TFT substrate) is a signal that travels between adjacent pixels on the liquid crystal side surface. Thin film transistors which are switching elements for selecting lines and pixels, pixel electrodes to which video signals are supplied through the thin film transistors, and the like are formed.

  The color filter is usually formed on another substrate (sometimes referred to as a counter substrate) facing the TFT substrate, but in recent years, the one provided on the TFT substrate side has been known. .

  Patent Documents 1 to 3 below each disclose a liquid crystal display device in which a color filter is provided on the TFT substrate side. Patent Document 1 shows a configuration in which color filters having different colors arranged on both sides of the signal line are overlapped on the upper surface of the signal line (source line). The width of the signal line and the angle of the tapered portion of the edge that overlaps the other color filter of the color filter are shown. Patent Document 2 also shows a configuration in which color filters of different colors arranged on both sides of the signal line are overlapped on the upper surface of the signal line (source line: indicated by a width of 14 μm in the drawing). In the table (Table 1), the width of the signal line and the angle of the tapered portion of the edge that is overlapped with another color filter of the color filter are shown. Patent Document 3 shows a configuration in which color filters of different colors arranged on both sides of the signal line are overlapped on the upper surface of the signal line. However, the width of the signal line and the angle of the tapered portion of the edge that overlaps the other color filter of the color filter are not specifically shown.

JP 2002-357828 A JP 2003-050387 A JP 2005/084231 A

  However, all of the liquid crystal display devices disclosed in Patent Documents 1 and 2 are configured such that the angle of the tapered portion on the edge that is overlapped with another color filter of the color filter is small. Moreover, although the angle of the taper part mentioned above of the color filter is not specifically disclosed in Patent Document 3, it can be estimated that the angle is small as well.

  For this reason, the width of the region where the color filter is overlapped with the other color filter is increased according to the small angle of the tapered portion. In the region where the color filter is overlapped with another color filter, a relatively large step is generated, and it is inevitable that an alignment abnormality is generated in the alignment film formed on the surface in direct contact with the liquid crystal. For this reason, for example, by increasing the width of the signal line in the lower layer, the above-described alignment abnormality is shielded from light. As a result, the area of the pixel surrounded by the signal line is narrowed, resulting in a decrease in the aperture ratio of the pixel. Will do.

  An object of the present invention is to provide a liquid crystal display device with an improved aperture ratio.

  In the liquid crystal display device of the present invention, the angle of the tapered portion of the edge that is overlapped with the other color filter of the color filter is increased, and the width of the signal line in the lower layer of the overlapped area of each color filter is decreased. It is in the configuration.

  The configuration of the present invention can be as follows, for example.

(1) The liquid crystal display device of the present invention is provided on the liquid crystal side surface of one of the pair of substrates opposed to each other with the liquid crystal interposed therebetween.
Gate signal lines made of a light-shielding material extending in the first direction and juxtaposed in the second direction intersecting the first direction, and light shielding extending in the second direction and juxtaposed in the first direction A drain signal line made of a conductive material,
A region surrounded by a pair of adjacent gate signal lines and a pair of adjacent drain signal lines is defined as a pixel region. A thin film transistor that is turned on by at least a scanning signal from the gate signal line in the pixel region, and the turned on thin film transistor A liquid crystal display device comprising a pixel electrode to which a video signal from the drain signal line is supplied,
Each of the pixel regions includes at least a gate signal line, a drain signal line, and a color filter formed in an upper layer of the thin film transistor,
In the adjacent color filter, the overlapping region of the first color filter and the second color filter is disposed in the drain signal line or the gate signal line formation region in plan view,
The taper angle of the first taper formed between the first taper formed in the overlapping region and located at the end of the first color filter and the surface of the drain signal line or the gate signal line is 45 ° or more 90 ° The taper of the second taper portion formed between the second taper portion that is set to be less than or equal to and formed in the overlap region and located at the end of the second color filter and the surface of the first color filter in the overlap region. The angle is set to 45 ° or more and 90 ° or less, and the width of the signal line is set to 1 μm or more and 4 μ or less .
The pixel electrode is formed in a region excluding the overlapping region in the pixel region .

(2) The liquid crystal display device of the present invention is provided on the liquid crystal side surface of one of the pair of substrates opposed to each other with the liquid crystal interposed therebetween.
Gate signal lines made of a light-shielding material extending in the first direction and juxtaposed in the second direction intersecting the first direction, and light shielding extending in the second direction and juxtaposed in the first direction A drain signal line made of a conductive material,
A region surrounded by a pair of adjacent gate signal lines and a pair of adjacent drain signal lines is defined as a pixel region. A thin film transistor that is turned on by at least a scanning signal from the gate signal line in the pixel region, and the turned on thin film transistor A liquid crystal display device comprising a pixel electrode to which a video signal from the drain signal line is supplied,
Each of the pixel regions includes at least a gate signal line, a drain signal line, and a color filter formed in an upper layer of the thin film transistor,
In the adjacent color filters, the overlapping region of the first color filter and the second color filter is narrower than the line width of the drain signal line or the gate signal line in plan view, and the drain signal line or the gate Placed in the signal line formation area,
The taper angle of the first taper formed between the first taper formed in the overlapping region and located at the end of the first color filter and the surface of the drain signal line or the gate signal line is 45 ° or more 90 ° The taper of the second taper portion formed between the second taper portion that is set to be less than or equal to and formed in the overlap region and located at the end of the second color filter and the surface of the first color filter in the overlap region. The angle is set to 45 ° to 90 °, and the width of the signal line is set to 1 μm to 4 μm.

(3) The liquid crystal display device of the present invention is characterized in that, in (1) or (2), the thickness of each of the color filters is set to 1 μm or more and 4 μm or less.
( 4 ) In the liquid crystal display device of the present invention, in (1) or (2) , the thickness of each color filter is set to 1 μm or more and 4 μm or less, and the first color filter and the second color filter It has a step of 1 μm or less in the overlapping portion.

( 5 ) In the liquid crystal display device of the present invention, in any one of (1) to ( 4 ), the tip of the first taper portion of the first color filter is overlapped with the second taper portion of the second color filter. It is characterized by being.

( 6 ) The liquid crystal display device of the present invention is the liquid crystal display device according to any one of (1) to ( 5 ), wherein the first taper portion formed in the overlap region and located at an end portion of the first color filter and the drain signal The taper angle of the first taper formed by the line or the surface of the gate signal line is set to 45 ° or more and 70 ° or less, and is formed in the overlap region and is located at the end of the second color filter. The taper angle of the second taper portion formed between the two taper portions and the surface of the first color filter in the overlapping region is set to 45 ° or more and 70 ° or less.

( 7 ) The liquid crystal display device of the present invention is characterized in that, in any one of (1) to ( 6 ), the pigment concentration in the color filter is 10% or more and 60% or less.

( 8 ) In the liquid crystal display device of the present invention, in any one of (1) to ( 7 ), the pigment concentration of the second color filter is smaller than or equal to the pigment concentration of the first color filter. .

( 9 ) In the liquid crystal display device of the present invention, in any one of (1) to ( 8 ), the color filter has a relative dielectric constant of 3.0 or more and 7.0 or less.

( 10 ) In the liquid crystal display device of the present invention, in any one of (1) to ( 9 ), the color filter is formed by a selective etching method using a photolithographic technique using an aligner or a stepper.

  The above-described configuration is merely an example, and the present invention can be modified as appropriate without departing from the technical idea. Further, examples of the configuration of the present invention other than the above-described configuration will be clarified from the entire description of the present specification or the drawings.

  Other effects of the present invention will become apparent from the description of the entire specification.

It is sectional drawing which shows the Example of the liquid crystal display device of this invention, and is sectional drawing in the II line | wire of FIG. It is a top view of the pixel which shows the Example of the liquid crystal display device of this invention. It is sectional drawing which shows the effect of the liquid crystal display device of this invention. It is sectional drawing of the pixel which shows the Example of the liquid crystal display device of this invention.

  Embodiments of the present invention will be described with reference to the drawings. In each drawing and each example, the same or similar components are denoted by the same reference numerals and description thereof is omitted.

  The liquid crystal display device of the present invention has a second direction that extends in the first direction and intersects the first direction on the liquid crystal side surface of one of the pair of substrates opposed to each other with the liquid crystal interposed therebetween. And a pair of adjacent gates formed with a gate signal line made of a light-shielding material arranged in parallel and a drain signal line made of a light-shielding material extended in the second direction and arranged in parallel in the first direction. A region surrounded by a signal line and a pair of adjacent drain signal lines is defined as a pixel region, a thin film transistor that is turned on by at least a scanning signal from the gate signal line in the pixel region, and the drain signal line through the turned on thin film transistor And a pixel electrode to which a video signal is supplied. Further, each of the pixel regions includes at least a gate signal line, a drain signal line, and a color filter formed on an upper layer of the thin film transistor. In addition, in the adjacent color filters of different colors, the first color filter which is one color filter is a color filter of the other without protruding from the formation region of the drain signal line or the gate signal line in a plan view. Overlaid on a certain second color filter. A first taper portion is formed at a portion of the first color filter that overlaps the second color filter. A second taper portion is formed on a portion of the second color filter that overlaps the first color filter. The taper angle of the first taper portion is set to 45 ° or more and 90 ° or less with respect to the surface of the drain signal line or the gate signal line, and the second taper of the second color filter formed in the overlap region. The taper angle of the portion is set to 45 ° to 90 ° with respect to the surface of the first color filter, and the width of the signal line is set to 1 μm to 4 μm.

<Pixel configuration>
FIG. 2 is a plan view showing the configuration of the pixel of the liquid crystal display device of the present invention. The liquid crystal display device is a 2.0 type, VGA (400 ppi) product. The pixel shown in FIG. 2 shows one of a plurality of pixels arranged in a matrix. For this reason, pixels having the same configuration are formed vertically and horizontally with respect to the illustrated pixel. FIG. 1 shows a pixel formed on a so-called TFT substrate among a pair of substrates arranged to face each other with a liquid crystal interposed therebetween. FIG. 1 shows a cross-sectional view taken along the line II in FIG.

  In FIG. 2, a semiconductor layer PS made of, for example, polysilicon is formed in an island shape on the surface of a substrate SUB1 (see FIG. 1). The semiconductor layer PS is a semiconductor layer of the thin film transistor TFT, and is configured by a pattern having a bent portion at the center and a large area at both ends. The thin film transistor TFT is a MIS (Metal Insulator Semiconductor) transistor having a so-called top gate type structure in which a gate electrode described later is formed above the semiconductor layer PS.

An insulating film GI (see FIG. 1) is formed on the surface of the substrate SUB1 so as to cover the semiconductor layer PS. The insulating film GI functions as a gate insulating film of the thin film transistor TFT and have contact to the formation region of the thin film transistor TFT.

  On the surface of the insulating film GI, gate signal lines GL extending in the x direction in the drawing and arranged in parallel in the y direction are formed. These gate signal lines GL are formed of a light shielding material. These gate signal lines GL are formed so as to run between the pixels arranged in parallel in the y direction in the drawing. Further, the gate signal line GL is formed so as to intersect with a part of the semiconductor layer PS, and a protrusion (indicated by reference numeral GLpj in the drawing) that intersects with another part of the semiconductor layer PS. have. As a result, the gate signal line GL has a function as a gate electrode (double gate) of the thin film transistor TFT at a portion intersecting the semiconductor layer PS. The semiconductor layer PS is doped with impurities using the gate electrode as a mask after the formation of the gate signal line GL, so that a channel region of the thin film transistor TFT or the like is formed in a region immediately below the gate electrode. ing.

  An interlayer insulating film IN1 (see FIG. 1) is formed on the surface of the insulating film GI so as to cover the gate signal line GL. The upper surface of the interlayer insulating film IN1 extends in the y direction in the drawing and extends in the x direction. Parallel drain signal lines DL are formed. These drain signal lines DL are formed of a light shielding material. These drain signal lines DL are formed so as to run between the pixels arranged in parallel in the x direction in the drawing. Here, the drain signal line DL has a width W of, for example, 3 μm, which is significantly narrower than the conventional one. This is to increase the pixel area and improve the pixel aperture ratio. The drain signal line DL is formed on a region where the area of one end of the semiconductor layer PS is large, and is electrically connected to one end of the semiconductor layer PS through a through hole TH1 previously formed in the interlayer insulating film IN1. ing. A portion of the drain signal line DL that is electrically connected to the semiconductor layer PS functions as the drain electrode DT of the thin film transistor TFT.

  When the drain signal line DL is formed, the source electrode ST of the thin film transistor TFT is formed on a region where the area of the other end of the semiconductor layer PS is large, and the source electrode ST is formed on the interlayer insulating film IN1. It is electrically connected to the other end of the semiconductor layer PS through a previously formed through hole TH2. The source electrode ST is connected to a pixel electrode PX described later.

  Thus, the surface of the interlayer insulating film IN1 on which the drain signal line DL (drain electrode DT) and the source electrode ST of the thin film transistor TFT are formed also covers the drain signal line DL (drain electrode DT) and the source electrode ST. Thus, a protective film PAS (see FIG. 1) is formed. The protective film PAS is formed, for example, to avoid contact with the liquid crystal of the thin film transistor TFT, and has a two-layer structure of, for example, an inorganic insulating film PAS1 (see FIG. 1) and an organic insulating film PAS2 (see FIG. 1).

  Here, the organic insulating film PAS2 is made of, for example, a resin material, and has a structure that also serves as the color filter CF. In FIG. 2, for example, the color filter CF has the same color as the pixel group of each pixel arranged in parallel in the y direction in the drawing, and is formed in a strip-like pattern covering each pixel. The color filter CF composed of such a band-like pattern is, for example, a blue (B) color filter CF (indicated by reference symbol CF (B) in the drawing) or a red (R) color filter in the x direction in the drawing. They are repeatedly arranged in the order of CF (indicated by reference symbol CF (R) in the figure) and green (G) color filter (indicated by reference symbol CF (G) in the figure). The pixel shown in FIG. 2 constitutes a unit pixel for color display together with, for example, two adjacent pixels on the left and right. The color filter CF (R) shown in FIG. 2 has an overlapping portion (color overlapping portion) on the color filter CF (B) adjacent to the left side in the drawing and the drain signal line DL (indicated by reference symbol DL (DLl) in the drawing). And has an overlapping portion (color overlapping portion) on the color filter CF (G) and the drain signal line DL (indicated by reference symbol DL (DLr) in the drawing) adjacent to the right side in the drawing. The configuration of the color filter CF will be described in detail later.

  On the upper surface of the color filter CF that also serves as the protective film PAS2, a counter electrode CT made of, for example, a transparent conductive film made of ITO (Indium Tin Oxide) is formed. The counter electrode CT is formed as a planar electrode covering almost the entire region in each pixel, and is formed in common for each pixel arranged in parallel in the x direction in the figure across the drain signal line DL, for example. A reference signal serving as a reference for the video signal is supplied to the counter electrode CT from the outside of the display area.

  An interlayer insulating film IN2 (see FIG. 1) is formed on the surface on which the counter electrode CT is formed so as to cover the counter electrode CT. A pixel electrode made of, for example, ITO is formed on the surface of the interlayer insulating film IN2 for each pixel. PX is formed. The pixel electrode PX is composed of, for example, a plurality of (for example, two in the drawing) linear electrodes extending in the y direction in the drawing and arranged in parallel in the x direction. The end portions of these electrodes in the same direction are connected to each other. This is because a plurality of electrodes have the same potential. The pixel electrode PX is connected to the source electrode ST of the thin film transistor TFT through the interlayer insulating film IN2, the protective film PAS2 (color filter CF), and the through hole TH3 formed in the protective film PAS1 at the end on the thin film transistor TFT side. And are electrically connected.

  Although not shown in FIG. 1, an alignment film is formed on the interlayer insulating film IN2 so as to cover the pixel electrode PX, and this alignment film is in direct contact with the liquid crystal, thereby initial alignment of liquid crystal molecules. The direction is decided.

<Configuration of color filter CF>
As shown in FIG. 1, the color filter CF includes a first color filter, a second color filter, and a third color filter. In the first embodiment, for example, the first color filter is a blue filter CF (B), the second color filter is a red filter CF (R), and the third color filter is a green filter CF (G). The color filters are formed in the order of a blue (B) color filter CF (B), a red (R) color filter CF (R), and a green (G) color filter CF (G). Each of these color filters CF has a film thickness of 2.0 μm. In this case, the color filters CF having different colors are arranged on the drain signal line DL so as to overlap each other.

  In FIG. 1, DLr is a drain signal line for sending a data signal to the red pixel, and DLg is a drain signal line for sending a data signal to the green pixel.

  On the red drain signal line DLr, the red filter CF (R) is overlaid on the blue filter CF (B). On the green drain signal line DLg, the green filter CF (G) is overlaid on the red filter CF (R). Although not shown in FIG. 1, on the blue drain signal line, the green filter CF (G) is superimposed on the blue filter CF (B). In the image display area, the color filters of the respective colors are arranged in a repeated state. Further, at both ends of the first color filter, a tapered portion having a taper angle θ1 when formed in a cross section is formed. When viewed in cross section, a taper portion having a taper angle θ21 is formed at one end portion of the second color filter when overlapped with the first color filter, and a cross section is formed at the other end portion of the second color filter. When seen in FIG. 2, a tapered portion having a taper angle θ22 is formed. When viewed in cross section, a taper portion having a taper angle θ31 is formed at one end portion of the third color filter when overlapped with the second color filter, and a cross section is formed at the other end portion of the third color filter. When viewed in the above, a tapered portion is formed at the overlapping portion with the first color filter. The overlapping region of each color filter is formed in a region narrower than the line width of the drain signal line.

While this embodiment is arranged to fit the area superimposed on the drain signal line, as good as similar configuration when disposed overlapping region to the gate signal line.

The end of the blue filter CF (B) is formed without protruding from the end of the drain signal line DLr on the pixel side where the red filter CF (R) is formed, and the surface of the drain signal line DLr is covered. taper having an angle .theta.1 (= 45 °) with respect are formed (the angle .theta.1 is sometimes referred to as taper angle). In order to obtain the taper angle θ1 in the blue filter CF (B), 30% of the blue pigment is contained in the resin material, and is obtained by performing selective etching by a photolithography technique. That is, the taper angle θ1 can be controlled by the pigment content.

  The end of the red filter CF (R) is formed without protruding from the end of the drain signal line DLl on the pixel side where the blue filter CF (B) is formed. Further, the taper angle θ21 of the taper portion of the red filter is set to 50 ° with reference to the surface of the first color filter (the angle θ21 may be referred to as a taper angle). In order to obtain the taper angle θ21 in the red filter CF (R), the resin material is obtained by containing 30% of a red pigment and performing selective etching by a photolithography technique. The photolithographic technique in this case can be processed with high accuracy by adopting a method using an aligner or a stepper. The other end of the red filter CF (R) is formed on a drain signal line DL (indicated by reference sign DLg in the figure) adjacent to the drain signal line DLr. The green filter CF (G) is formed without protruding from the end of the drain signal line DLr on the pixel side where the green filter CF (G) is formed, and an angle θ22 (= 50 °) is defined with respect to the surface of the drain signal line DLr. A taper is formed.

  The end of the green filter CF (G) is formed without protruding from the end of the drain signal line DLl on the pixel side where the color filter CF (R) is formed. Further, a taper having an angle θ3 (= 60 °) with respect to the surface of the drain signal line DLg is formed (the angle θ3 may be referred to as a taper angle). In order to obtain the taper angle θ3 in the green filter CF (G), 40% of a blue pigment is contained in the resin material and selective etching is performed by a photolithography technique.

  The color filter CF configured as described above has a relatively large taper angle at the end thereof, so that even if adjacent color filters CF of different colors are overlapped with each other, the overlapping portion region ( The width of the overlapping region can be made relatively small. The overlapping region can be accommodated in a region having a width W (= 3 μm) of the drain signal line DL. Thus, the width of the drain signal line DL can be reduced to the above-described value, and the aperture ratio of the pixel can be improved.

  Note that, in the case of the configuration as described above, it can be confirmed that the step generated in the overlapping portion of the color filters CF having different colors can be greatly reduced. FIG. 3 is a diagram showing that the color filter CF (B), the color filter CF (R), the color filter CF (G), and the color filter CF (B) are adjacent to each other with overlapping in order from the left side in the drawing. . As shown in FIG. 3, the step DL1 in the color filter CF (R) on the color filter CF (B) is 0.4 μm, and the step DL2 in the color filter CF (G) on the color filter CF (B) is 0.6 μm. The step DL3 in the color filter CF (G) on the color filter CF (R) was 0.8 μm. These steps can be made much smaller than in the prior art, and the width of the drain signal line DL is set to a width W (= 3 μm) within the range in which the alignment abnormality occurs in the alignment film formed on the surface in direct contact with the liquid crystal. To be able to fit in. 2 and 3, the end of the upper color filter extends to the flat portion of the lower color filter (a surface parallel to the upper surface of the signal wiring).

In this way, in the configuration shown in the first embodiment, the applied product, the TFT wiring width (width of the drain signal line DL), the aperture ratio (pixel aperture ratio), the GRB stacking order (the stacking order of each color filter), When the GRB characteristic (characteristic of each color filter) and the color overlap step (step difference in the overlap of each color filter) are sequentially extracted and described, the result shown in the row corresponding to Example 1 is shown in Table 1 below.

  That is, as shown in FIG. 2, the color filter CF (B), the color filter CF (R), and the color filter CF (G) are formed in the order in which the color filters CF having different colors are formed. In this case, when the color filter CF (G) has a pigment concentration of 40% and a film thickness of 2.0 μm, the relative permittivity is 3.7 and the taper angle θ3 of the edge is 60 °. When the CF (R) pigment concentration is 30% and the film thickness is 2.0 μm, the relative dielectric constant is 3.5, the taper angle θ2 of the edge is 50 °, and the color filter CF (B) When the pigment concentration is 30% and the film thickness is 2.0 μm, the relative dielectric constant is 3.6 and the taper angle θ1 of the edge is 50 °. Further, the step of the color filter CF (R) on the color filter CF (B) is 0.4 μm, the step of the color filter CF (G) on the color filter CF (B) is 0.6 μm, and the color filter CF (R) The step of the color filter CF (G) above is 0.8 μm. By doing so, the aperture ratio of the pixel was able to be 65%.

  Further, the end of the upper color filter in FIG. 4 is in the tapered portion of the lower color filter. Even in such a configuration, the taper angle θ1 of the first taper portion of the first color filter formed in the overlapping region is set to 45 ° or more and 90 ° or less with respect to the surface of the drain signal line or the gate signal line. The taper angle θ2 of the second taper portion of the second color filter formed in the overlapping region is set to 45 ° or more and 90 ° or less with reference to the surface of the first color filter, and the width of the signal line is 1 μm or more and 4μ. Set to:

  With this configuration, in the adjacent color filters, the overlapping region of the first color filter and the second color filter is disposed in the drain signal line or gate signal line formation region in plan view. The

  Hereinafter, in each of the following embodiments, the schematic configuration is the same as that shown in FIGS. 1 to 3, and therefore, description will be made based on Table 1 below.

  Applicable products are the same as in Example 1. In each pixel of the unit pixel, the stacking order of the color filters CF is green (G), red (R), and blue (B). In the following description, for the sake of convenience, green is simply referred to as G, red is simply referred to as R, and blue is simply referred to as B.

  The G color filter had a pigment concentration of 20%, a film thickness of 4.0 μm, a relative dielectric constant of 3.6, and a taper angle of 45 °. The R color filter had a pigment concentration of 10%, a film thickness of 4.0 μm, a relative dielectric constant of 3.0, and a taper angle of 45 °. The color filter of B had a pigment concentration of 10%, a film thickness of 4.0 μm, a relative dielectric constant of 3.3, and a taper angle of 45 °. The color overlapping step is 0.2 μm in the R color filter on the G color filter, 0.2 μm in the B color filter on the G color filter, and 0.2 μm in the B color filter on the R color filter. there were. As a result, the wiring width could be 4 μm and the pixel aperture ratio could be 62%.

  Applicable products are the same as in Example 1. In each pixel of the unit pixel, the stacking order of the color filters is B, R, and G.

  The color filter of B had a pigment concentration of 40%, a film thickness of 1.0 μm, a relative dielectric constant of 5.0, and a taper angle of 70 °. The R color filter had a pigment concentration of 50%, a film thickness of 1.0 μm, a relative dielectric constant of 6.0, and a taper angle of 80 °. The G color filter had a pigment concentration of 60%, a film thickness of 1.0 μm, a relative dielectric constant of 7.0, and a taper angle of 90 °. The color overlapping step is 0.4 μm in the R color filter on the B color filter, 0.6 μm in the G color filter on the B color filter, and 0.8 μm in the G color filter on the R color filter. there were. As a result, the wiring width could be 2 μm and the pixel aperture ratio could be 69%.

  In the case of Example 3, the pigment concentration in the color filter on the lower layer side of the color overlap is smaller than the pigment concentration of the color filter on the upper layer side (the pigment concentration is equal as shown in the following Example 4). May be the case). In this case, when the pigment concentration is low, the taper angle becomes small, so that the taper angle can be made lower. In this case, as can be seen from Table 1, the effect of reducing the color overlap step can be achieved.

  Applicable products are the same as in Example 1. In each pixel of the unit pixel, the stacking order of the color filters is G, R, and B.

  The G color filter had a pigment concentration of 50%, a film thickness of 1.0 μm, a relative dielectric constant of 7.0, and a taper angle of 90 °. The R color filter had a pigment concentration of 40%, a film thickness of 1.0 μm, a relative dielectric constant of 6.0, and a taper angle of 80 °. The color filter of B had a pigment concentration of 40%, a film thickness of 1.0 μm, a relative dielectric constant of 5.0, and a taper angle of 70 °. The color overlap step is 1.0 μm for the R color filter on the G color filter, 0.8 μm for the B color filter on the G color filter, and 0.6 μm for the B color filter on the R color filter. there were. As a result, the wiring width could be 2 μm and the pixel aperture ratio could be 69%.

  Applicable products are 4.0 type and QVGA (100 ppi). In each pixel of the unit pixel, the stacking order of the color filters is R, G, and B.

  The R color filter had a pigment concentration of 30%, a film thickness of 2.8 μm, a relative dielectric constant of 4.0, and a taper angle of 55 °. The G color filter had a pigment concentration of 30%, a film thickness of 3.0 μm, a relative dielectric constant of 4.0, and a taper angle of 50 °. The color filter of B had a pigment concentration of 30%, a film thickness of 2.6 μm, a relative dielectric constant of 4.0, and a taper angle of 60 °. The color overlapping step is 0.4 μm for the G color filter on the R color filter, 0.5 μm for the B color filter on the R color filter, and 0.6 μm for the B color filter on the G color filter. there were. As a result, the wiring width could be 3 μm, and the aperture ratio of the pixel could be 91%.

  Applicable products are the same as in Example 1. In each pixel of the unit pixel, the stacking order of the color filters is G, R, and B.

  The G color filter had a pigment concentration of 20%, a film thickness of 1.0 μm, a relative dielectric constant of 3.9, and a taper angle of 60 °. The R color filter had a pigment concentration of 10%, a film thickness of 1.0 μm, a relative dielectric constant of 3.3, and a taper angle of 60 °. The color filter of B had a pigment concentration of 10%, a film thickness of 1.0 μm, a relative dielectric constant of 3.6, and a taper angle of 60 °. The color overlapping step is 0.4 μm in the R color filter on the G color filter, 0.4 μm in the B color filter on the G color filter, and 0.4 μm in the B color filter on the R color filter. there were. As a result, the wiring width could be 4 μm and the pixel aperture ratio could be 62%.

  Applicable products are the same as in Example 1. In each pixel of the unit pixel, the stacking order of the color filters is B, R, and G.

  The color filter of B had a pigment concentration of 40%, a film thickness of 4.0 μm, a relative dielectric constant of 4.0, and a taper angle of 60 °. The R color filter had a pigment concentration of 50%, a film thickness of 4.0 μm, a relative dielectric constant of 5.0, and a taper angle of 70 °. The G color filter had a pigment concentration of 60%, a film thickness of 4.0 μm, a relative dielectric constant of 6.0, and a taper angle of 80 °. The color overlapping step is 0.3 μm for the R color filter on the B color filter, 0.5 μm for the G color filter on the B color filter, and 0.7 μm for the G color filter on the R color filter. there were. As a result, the wiring width could be 2 μm and the pixel aperture ratio could be 69%.

(Comparative Example 1)
Applicable products are the same as in Example 1. In each pixel of the unit pixel, the stacking order of the color filters is G, R, and B.

  The G color filter had a pigment concentration of 40%, a film thickness of 2.0 μm, a relative dielectric constant of 3.7, and a taper angle of 10 °. The R color filter had a pigment concentration of 30%, a film thickness of 2.0 μm, a relative dielectric constant of 3.5, and a taper angle of 10 °. The color filter of B had a pigment concentration of 30%, a film thickness of 2.0 μm, a relative dielectric constant of 3.6, and a taper angle of 10 °. The color overlapping step is 1.2 μm in the R color filter on the G color filter, 1.2 μm in the B color filter on the G color filter, and 1.2 μm in the B color filter on the R color filter. there were. As a result, the wiring width was 12 μm, and the aperture ratio of the pixel was only 33%.

  In the embodiment described above, the overlapping portion of the color filters having different colors is performed on the drain signal line DL. However, the present invention is not limited to this and may be performed on the gate signal line GL. In this case, the present invention can also be applied to the gate signal line GL.

  In the embodiment described above, an IPS (In Plane Switching) type liquid crystal display device has been described. However, the present invention is not limited to this, and can be applied to, for example, a TN (Twisted Nematic) type or VA (Vertical Alignment) type liquid crystal display device.

  The present invention has been described using the embodiments. However, the configurations described in the embodiments so far are only examples, and the present invention can be appropriately changed without departing from the technical idea. Further, the configurations described in the respective embodiments may be used in combination as long as they do not contradict each other.

SUB1 ... Substrate, PS ... Semiconductor layer, TFT ... Thin film transistor, GI ... Insulating film, GL ... Gate signal line, IN1 ... Interlayer insulating film, DL ... Drain signal line, TH1, TH2, TH3 ... Through hole, PAS ... protective film, PAS1 ... inorganic protective film, PAS2 ... organic protective film, CT ... counter electrode, IN2 ... interlayer insulating film, PX ... pixel electrode, CF ... color filter, CF ( B) …… Blue color filter, CF (R) …… Red color filter, CF (G) …… Green color filter.

Claims (10)

The liquid crystal side surface of one of the pair of substrates opposed to each other with the liquid crystal sandwiched between them,
Gate signal lines made of a light-shielding material extending in the first direction and juxtaposed in the second direction intersecting the first direction, and light shielding extending in the second direction and juxtaposed in the first direction A drain signal line made of a conductive material,
A region surrounded by a pair of adjacent gate signal lines and a pair of adjacent drain signal lines is defined as a pixel region. A thin film transistor that is turned on by at least a scanning signal from the gate signal line in the pixel region, and the turned on thin film transistor A liquid crystal display device comprising a pixel electrode to which a video signal from the drain signal line is supplied,
Each of the pixel regions includes at least a gate signal line, a drain signal line, and a color filter formed in an upper layer of the thin film transistor,
In the adjacent color filter, the overlapping region of the first color filter and the second color filter is disposed in the drain signal line or the gate signal line formation region in plan view,
The taper angle of the first taper formed between the first taper formed in the overlapping region and located at the end of the first color filter and the surface of the drain signal line or the gate signal line is 45 ° or more 90 ° The taper of the second taper portion formed between the second taper portion that is set to be less than or equal to and formed in the overlap region and located at the end of the second color filter and the surface of the first color filter in the overlap region. The angle is set to 45 ° or more and 90 ° or less, and the width of the signal line is set to 1 μm or more and 4 μ or less .
The liquid crystal display device , wherein the pixel electrode is formed in a region excluding the overlapping region in the pixel region . The liquid crystal side surface of one of the pair of substrates opposed to each other with the liquid crystal sandwiched between them,
Gate signal lines made of a light-shielding material extending in the first direction and juxtaposed in the second direction intersecting the first direction, and light shielding extending in the second direction and juxtaposed in the first direction A drain signal line made of a conductive material,
A region surrounded by a pair of adjacent gate signal lines and a pair of adjacent drain signal lines is defined as a pixel region. A thin film transistor that is turned on by at least a scanning signal from the gate signal line in the pixel region, and the turned on thin film transistor A liquid crystal display device comprising a pixel electrode to which a video signal from the drain signal line is supplied,
Each of the pixel regions includes at least a gate signal line, a drain signal line, and a color filter formed in an upper layer of the thin film transistor,
In the adjacent color filters, the overlapping region of the first color filter and the second color filter is narrower than the line width of the drain signal line or the gate signal line in plan view, and the drain signal line or the gate Placed in the signal line formation area,
The taper angle of the first taper formed between the first taper formed in the overlapping region and located at the end of the first color filter and the surface of the drain signal line or the gate signal line is 45 ° or more 90 ° The taper of the second taper portion formed between the second taper portion that is set to be less than or equal to and formed in the overlap region and located at the end of the second color filter and the surface of the first color filter in the overlap region. An angle is set to 45 ° to 90 °, and a width of the signal line is set to 1 μm to 4 μm. 3. The liquid crystal display device according to claim 1, wherein the film thickness of each of the color filters is set to 1 μm to 4 μm. Each of the film thickness of the color filter is set below 4μm than 1 [mu], and characterized by having the following steps 1μm at the overlapping portion of the second color filter and the first color filter according to claim 1 or 2 A liquid crystal display device according to 1. The liquid crystal display device according to any one of claims 1 to 4 the tip of the first taper portion of the first color filter is characterized in that superimposed on the second tapered portion of the second color filter. The taper angle of the first taper formed by the first taper formed in the overlap region and located at the end of the first color filter and the surface of the drain signal line or the gate signal line is 45 ° or more. The second taper portion which is set to 70 ° or less, is formed in the overlap region, and is formed by a second taper portion located at an end portion of the second color filter and a surface of the first color filter in the overlap region. the liquid crystal display device according to any one of claims 1 to 5 taper angle is characterized by being set to 70 ° or less 45 ° or more. The liquid crystal display device according to any one of claims 1 to 6, characterized in that the pigment concentration becomes 60% or less than 10% of the color filter. The liquid crystal display device according to any one of claims 1 to 7 the pigment concentration of said second color filter is characterized by equal to or less than the pigment concentration of the first color filter. The liquid crystal display device according to any one of claims 1 to 8, wherein the dielectric constant of the color filter is 3.0 to 7.0. The color filter liquid crystal display device according to any one of claims 1 to 9, characterized in that it is formed by selective etching by the photolithography technique by aligner or stepper.

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