JP3066192B2 - Method for manufacturing reflective active matrix substrate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflection type activator used in a reflection type liquid crystal display device which does not use a backlight.
Ibumatorikusu about the method of manufacturing a substrate.

[0002]

2. Description of the Related Art In recent years, applications of liquid crystal display devices to word processors, laptop personal computers, pocket televisions, and the like have been rapidly advancing. In particular, among liquid crystal display devices, a reflection type liquid crystal display device that performs display by reflecting light incident from the outside is notable because a backlight is not required, so that power consumption is low, and thin and light weight can be achieved. ing. Conventionally, a TN (twisted nematic) method and an STN (super twisted nematic) method have been used for such a reflection type liquid crystal display device.

However, in these systems, the display becomes dark because half of the light intensity of natural light is inevitably used for display by a linear polarizer attached to the liquid crystal display device. Therefore, a display mode has been proposed in which all rays of natural light are effectively used. One of them is a phase transition type guest-host system (DL Whiteea).
nd G. N. Taylor. J. Appl. Phys
s. 45 4718974).

A liquid crystal display device having a display mode of this type utilizes a cholesteric-nematic phase transition phenomenon caused by an electric field and does not require a polarizing plate such as a linear polarizer.
A reflection type multi-color display in which a micro color filter is further combined with such a liquid crystal display device has been proposed (Tatsuo Uchida etc Pro).
seedings of the SID Vol.
29 157 1988).

In order to obtain a brighter display in a display mode that does not require such a polarizing plate, it is necessary to increase the intensity of light scattered in a direction perpendicular to the display screen with respect to incident light from all angles. There is. For that purpose, it is necessary to control the reflection characteristics on the reflection plate and to manufacture a reflection plate having the optimum reflection characteristics. In the literature that proposes the above-mentioned reflective multicolor display, a reflector in which a metal thin film of Ag or the like is formed on the glass substrate having the irregularities by controlling the shape of the irregularities formed on the surface of the insulating glass substrate. Is described.

[0006]

However, in the above-mentioned reflector, the surface of the glass substrate is scratched with an abrasive to form an uneven shape. Therefore, uneven portions having a uniform shape are not formed, and the reproducibility of the shape is poor. There is a disadvantage that it is bad. Further, when such a glass substrate is used, a reflective liquid crystal display device having good reflection characteristics cannot be provided stably.

The applicant of the present invention has proposed the following reflector in order to improve the above drawbacks (Japanese Patent Application No. Hei 3-4573).
issue). This reflective plate is formed by applying a photosensitive resin to an insulating substrate to form a pattern, then performing a heat treatment to cut off the upper edge of the pattern portion so as to be rounded, and then forming the insulating substrate on which the pattern is formed. A polymer resin film is formed by flowing a polymer resin on the substrate, and a reflective thin film having a light reflecting function is formed on the polymer resin film.

[0008] The reflector thus manufactured is bright with little multiple reflection because the surface of the reflective thin film is smooth. However, the reflective thin film on the insulating substrate portion where no pattern is formed may be flat, and in some cases, there is a problem that reflected light having a wavelength dependence is generated and an interference color is generated.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem of the prior art, and has a reflection type active matrix which has good reflection characteristics with little wavelength dependence and can obtain reflection characteristics with good reproducibility. An object of the present invention is to provide a method for manufacturing a substrate .

[0010]

According to the present invention, there is provided a method of manufacturing a reflective active matrix substrate , comprising the steps of:
Pixel electrodes made of a material having a projection function
And the upper surface of the pixel electrode is formed in a continuous wave shape.
Manufacturing method of a reflective active matrix substrate
And at least two or more heights are formed at the locations where the pixel electrodes are formed.
Forming a different convex portion, and forming a base on which the convex portion is formed.
A polymer tree with a continuous wavy upper surface on a plate
Forming a fat film, and a light reflector on the polymer resin film
Forming a pixel electrode made of a material having a function.
It is characterized by including the above purpose
Achieved. Reflective active matrix substrate of the present invention
The method of manufacturing a material having a light reflecting function on an insulating substrate
Pixel electrodes made of a material are arranged in a matrix,
A reflective actuated electrode with a continuous wavy upper surface.
A method for manufacturing a passive matrix substrate, comprising:
At least two or more projections with different heights
Step of forming using a polymer resin and forming the convex portion
The substrate is subjected to a heat treatment, and a polymer resin forming the convex portion is formed.
Softening and rounding the corners of the projection,
Process to form picture element electrode made of material having light reflection function
And is characterized by including
The objective is achieved. Reflective active matrices of the present invention
The method of manufacturing a substrate has a light reflection function on an insulating substrate.
Pixel electrodes made of a material having
And the upper surface of the pixel electrode is formed into a continuous wavy shape.
A method for manufacturing a projection type active matrix substrate,
At least two or more diameters are different
Using a photomask with randomly arranged circles
And at least two or more projections with different heights
Forming a material having a light reflecting function on the convex portion
Forming a pixel electrode made of a material.
The purpose is thereby achieved.

[0011]

[0012]

[0013]

[0014]

The generation of interference light will be described with reference to FIG. This figure shows a state in which light is incident from the glass substrate side, and the incident light is reflected by the reflection film and emitted from the glass substrate. In this case, it is considered that the generation of the interference light occurs when the light incident at the incident angle θi is reflected on the convex part and the foot part of the reflection film and is emitted at the emission angle θo. The optical path difference δ between the two lights at that time is expressed by the following equation.

Δ = L sin θi + h (1 / cos θi ′ + 1 / cos θo ′) · n− {Lsine θo + h (tan θi ′ + tan θo ′) sin θo } = L (sin θi−sin θo) + h ｛(1 / cos θi ′ + 1 / cos θo ′)・ N− (tan θi ′ + tan θo ′) sin θo｝ (1) where θi ′ is the incident angle at the foot of the reflection film θo ′ is the emission angle L at the foot of the reflection film L is both light to the glass substrate The distance between the incident points, h, is the height of the reflecting film from which the two lights are reflected with respect to the foot of the projection. N is the refractive index of the glass substrate. At this time, θi = θo = θ, θi ′ = θ
If o ′ = θ ′, the optical path difference δ is expressed by the following two equations.

Δ = h {2n / cos θ′−2 tan θ ′ · sin θ} (2) On the other hand, considering arbitrary wavelengths λ1 and λ2, δ / λ1 = m
When ± 1/2 (m is an integer), they weaken each other, and when δ / λ2 = m, they strengthen each other. Therefore, the following three equations hold.

Δ (1 / λ1-1 / λ2) = 1/2 (3) These three equations are also expressed as the following four equations.

Δ = (λ 1 · λ 2) / 2 · (λ 2 -λ 1) (4) Therefore, according to the above equations 2 and 4, the height h becomes
It is expressed by an equation.

H = １ ／ · {(λ 1 · λ 2) / (λ 2 −λ 1)} · {cos θ ′ / (2n−2 sin θ ′ · sin θ)} (5) From the above, the present inventors have obtained It has been found that the interference surface can be eliminated by forming the reflection surface of the reflection film into a continuous wave shape.

Therefore, the present invention provides a method for forming such a reflective film, in which at least two or more convex portions having different heights are formed on a plate-shaped base member, and further, the convex portions are provided. A polymer resin film was formed on the base member, and a reflective thin film was formed thereon using a material having a light reflecting function.

When the reflective thin film thus formed is applied to a picture element electrode of an active matrix substrate, the picture element electrode has a continuous wavy reflection surface, so that interference of reflected light is eliminated. In the case where the projections are formed optically using a photomask, the projections can be formed with good reproducibility under the same light irradiation conditions.

[0022]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a plan view of one embodiment of the active matrix substrate of the present invention, and FIG. 2 is a sectional view taken along line AA of FIG. In the reflection type active matrix substrate 20, a plurality of gate bus lines 22 as scanning lines and source bus lines 24 as signal lines are provided on a glass substrate 11 which is an insulating substrate so as to cross each other. . A pixel electrode 19 having a light reflecting function is arranged in a rectangular area surrounded by each gate bus line 22 and each source bus line 24. Each picture element electrode 19
Are located at the corners in the area where the gate bus lines 22 are located.
Gate electrode 23 extending from pixel electrode 19 toward pixel electrode 19
And a thin film transistor (TFT) 21 is formed as a switching element at the tip of the gate electrode 23. The gate electrode 23 forms a part of the TFT 21.

From the source bus line 24, the picture element electrode 19
And a source electrode 25 extending toward
The tip of the source electrode 25 is superposed on the gate electrode 23 in an insulated state to form a part of each TFT 21. On the gate electrode 23, the TFT 21 is spaced apart from the source electrode 25, and overlaps the gate electrode 23 in an insulated state.
Of the drain electrode 2 is provided.
6 are electrically connected to the pixel electrodes 19, respectively.

As shown in FIG. 2, the TFT 21 is provided above the gate electrode 23 formed on the glass substrate 11. The gate electrode 23 is covered with a gate insulating film 11a laminated on the entire glass substrate 11,
On the gate insulating film 11a, a semiconductor layer 27 is laminated so as to cover above the gate electrode 23. A pair of contact layers 28, 2
8, the source electrode 25 is formed on one contact layer 28, and the drain electrode 26 is formed on the other contact layer 28.

On the other hand, under the picture element electrode 19 having the above-mentioned light reflection function, high and low convex portions 14a and 14b formed alternately on the glass substrate 11 are provided. There is a polymer resin film 15 formed on the portions 14a and 14b. The upper surface of the polymer resin film 15 has a continuous wavy shape due to the presence of the above-described protrusions 14a and 14b. The polymer resin film 15 is formed not only below the pixel electrodes 19 but also over substantially the entire surface of the glass substrate 11, and in this embodiment, for example, OFPR-800 manufactured by Tokyo Ohka Co., Ltd. is used as the material. .
The above-described pixel electrode 19 is formed on the portion of the polymer resin film 15 that is present on the convex portions 14a and 14b and has a continuous upper surface in a wavy shape. It is made of, for example, Al having a function.
The picture element electrode 19 is electrically connected to the drain electrode 26 via the contact hole 29.

Next, a method of forming the picture element electrode 19, which is a main part of the reflection type active matrix substrate, will be described with reference to FIG.

First, as shown in FIG. 3A, a resist film 12 made of a photosensitive resin is formed on a glass substrate 11 by a spin coating method. In the present embodiment, for example, a glass substrate 11 having a trade name of 7059 and a thickness of 1.1 mm manufactured by Corning Incorporated was used. Also,
As the resist film 12, the above-mentioned OFPR-800 photosensitive resin, which is the same material as the polymer resin film 15, is used.
Preferably 500r. p. m. To 3000r. p.
m. Formed by the spin coating method. In this embodiment, 1500 r. p. m. For 30 seconds, and the thickness of the resist film 12 was 2.5 μm.

Next, the glass substrate 11 on which the resist film 12 has been formed is pre-baked at, for example, 90 ° C. for 30 minutes. Subsequently, as shown in FIG. 4, for example, a photomask 13 in which two types of circular pattern holes 13a and 13b are formed in a plate 13c is used.
As shown in (b), it is arranged above the resist film 12,
Exposure is performed from above the photomask 13 as shown by arrows in the figure. In the photomask 13 of the present embodiment, a circular pattern hole 13a having a diameter of 5 μm and a circular pattern hole 13b having a diameter of 3 μm are randomly arranged. They are separated by at least 2 μm or more. However, if the distance is too large, the upper surface of the polymer resin film 15 is unlikely to have a continuous wavy shape.

Next, development is performed using, for example, a 2.38% concentration developer consisting of NMD-3 manufactured by Tokyo Ohka Co., Ltd.
As a result, as shown in FIG.
Are provided on one surface with fine projections 14a ',
4b 'are formed in large numbers. These convex portions 14a ', 14
b 'has a sharp upper edge. In this embodiment, the diameter is 5 μm
Of the 2.48 μm height projections 1
4a was formed, and a convex portion 14b having a height of 1.64 μm was formed by the pattern hole 13b having a diameter of 3 μm. The height of these projections 14a 'and 14b' is
The size of the pattern holes 13a and 13b can be changed according to the size of the holes 13a and 13b, the exposure time, and the development time, and is not limited to the above-described size.

Next, as shown in FIG.
The heat treatment is performed by heating the glass substrate 11 on which a 'and 14b' are formed at 200 ° C. for 1 hour. As a result, FIG.
As shown in (c), the developed convex portions 14a 'and 14b' each having a corner at the upper end portion are softened, so that the corner is rounded, that is, the cross-section is substantially circular with the corner cut off. The projections 14a and 14b are formed.

Next, as shown in FIG. 3E, a polymer resin is spin-coated on the heat-treated glass substrate 11 to form a polymer resin film 15. The above-mentioned OFPR-800 is used as the polymer resin.
000r. p. m. ~ 3000r. p. m. Spin coat with. In this embodiment, 2000r. p. m. Was spin-coated. As a result, even if the upper portion of the glass substrate 11 on which the protrusions 14a and 14b are not formed is flat, the wavy polymer resin film 15 having a continuous upper surface is formed.

Finally, a pixel electrode 19 made of Al was formed at a predetermined position on the polymer resin film 15 by, for example, sputtering. Examples of a material suitable for the pixel electrode 19 include Al, Ni, Cr, Ag, and the like having a light reflecting function.
The thickness of 9 is suitably about 0.01 to 1.0 μm.

The pixel electrode 19 having the light reflecting function formed in this manner is connected to the polymer resin film 15 as described above.
Is formed in a continuous wavy form on the upper surface thereof, so that the upper surface also has a continuous wavy form.

By the way, the wavelength dependence of the light reflected from the picture element electrode 19 having a light reflecting function in which the upper surface has a continuous wave shape was measured as shown in FIG. As a measurement condition, the measurement side has a configuration assuming the use state of the pixel electrodes 19 in an actual liquid crystal display device. Specifically, a glass dummy glass 18 having a refractive index of about 1.5, which is substantially equal to the refractive index of the actual liquid crystal layer, is used as a glass substrate.
9 is formed on the active matrix substrate 9 on which the UV-curable adhesive 17 having a refractive index of 1.5 is adhered.

On the other hand, on the measurement side, the light source L1 is arranged so that the incident light L1 'is incident at an incident angle θi with respect to the normal m1 on the dummy glass 18, and the light receiving angle is set with respect to the normal m2. A photomultimeter L2 is provided to capture light at a fixed angle reflected in the direction of θo. Therefore, the photomultimeter L2 detects the incident angle θ1 of the scattered light reflected by the incident light L1 ′ incident on the dummy glass 18 at the incident angle θi.
Capture the intensity of the scattered light L2 'reflected at o. In this embodiment, in order to prevent the photomultimeter L2 from catching the specularly reflected light in which the light emitted from the light source L1 is reflected on the surface of the dummy glass 18, the conditions are set as θi = 30 ° and θi = 20 °. It was measured.

For comparison, the picture element electrode 19a (Comparative Example 1) formed as shown in FIG.
The measurement was also performed on the picture element electrode 19b (Comparative Example 2) formed as shown in (b). Picture element electrode 19 of Comparative Example 1
a is directly formed on the cut-off convex portions 14a and 14b without the polymer resin film, and the convex portions 14a and 14b are formed.
Except for the upper part of 4b, there is a flat part 16a. The pixel electrode 19b of Comparative Example 2 has a convex portion 14 having a corner at the upper end.
On top of a 'and 14b', a polymer resin film 15 is interposed therebetween, and the upper portions of the projections 14a 'and 14b' are formed substantially flat. Both picture element electrodes 19a and 19b
Use Al.

FIG. 8 shows the wavelength dependence of the reflected light of this embodiment, and FIGS. 9A and 9B show the reflection characteristics of the reflected light of Comparative Examples 1 and 2. In each figure, the horizontal axis represents wavelength, and the vertical axis represents reflectance. As can be understood from these figures, each of the comparative examples has a wavelength dependency in the reflectance, and has a defect that an interference color occurs. On the other hand, in the present embodiment, the wavelength dependency is hardly recognized in the reflectance. Good white color. Since the measurement is performed under the above-described conditions, the obtained result is equivalent to the reflection characteristic at the boundary between the surface of the pixel electrode 19 and the actual liquid crystal layer.

The pattern holes 13 of the photomask 13
Although the shapes of a and 13b are circular in this embodiment,
It may have another shape, for example, an arbitrary shape such as a rectangle, an ellipse, and a stripe.

In the above embodiment, two convex portions 1 having different heights are used.
Although 4a and 14b are formed, the present invention is not limited to this, and three or more convex portions having different heights may be formed.

In the present invention, the height of the convex portion is changed by two or more for the following reason. That is, if the heights are the same, light reflected on the upper surface of the pixel electrode formed on the two adjacent protrusions easily causes interference. Therefore, in the present invention, if the heights of the convex portions are made to be variously different, the wavelength dependency can be further eliminated.

However, as shown in FIG. 1, when the pixel electrode 19 is formed so as to overlap a part of the gate bus line 22 or a part of the source bus line 24, the overlapped pixel electrode 1 is formed.
It is preferable that the edge portion of No. 9 does not have a convex portion. By doing so, it is possible to eliminate patterning defects of the pixel electrodes 19. Further, by doing so, the pixel electrode 19 can be formed so as to overlap the gate bus line 22 and the source bus line 24,
Since the interval between the pixel electrode 19 and the gate bus line 22 and the interval between the pixel electrode 19 and the source bus line 24 can be eliminated, there is an advantage that the area of the pixel electrode 19 can be increased. If the area of the pixel electrode 19 can be increased, the aperture ratio of the display screen increases, and a bright display can be achieved. However, when insulation failure is a problem, it is preferable not to form a convex portion on the overlapping portion.

In the above embodiment, OFPR-800 manufactured by Tokyo Ohka Co., Ltd. is used as the photosensitive resin material. However, the present invention is not limited to this, and the exposure process can be performed regardless of the negative type or the positive type. Any photosensitive resin material that can be used and patterned can be used. For example, OMR-
83, OMR-85, ONNR-20, OFPR-2,
OFPR-830 or OFPR-500, or Shipley's TF-20, 1300-
27, or 1400-27. In addition, Toray's Photo Nice, Sekisui Fine Chemical's RW
101, R101, R633, etc., manufactured by Nippon Kayaku Co., Ltd.

FIG. 10 shows an embodiment of the reflection type liquid crystal display device 10 using the reflection type active matrix substrate 20. In the reflection type liquid crystal display device 10, a counter substrate 30 is provided so as to face the reflection type active matrix substrate 20, and an adhesive sealant mixed with a 7 μm spacer is screen-printed between the substrates 20 and 30. The liquid crystal layer 34 is formed by being sealed by a liquid crystal sealing layer (not shown) formed as described above.

The opposing substrate 30 has an insulating complementary color filter plate 31 formed on a glass substrate 33 and an ITO (Indi) color filter plate 31 on the entire surface of the complementary color filter plate 31.
A transparent electrode 32 having a thickness of 100 nm (umTin Oxide) and a liquid crystal alignment film 33 are formed. The liquid crystal alignment film 33 is also formed on the inner surface of the reflection type active matrix substrate 20 on the liquid crystal layer 34 side.

The reflection type active matrix substrate 20
The counter substrate 30 is formed by applying a liquid crystal alignment film 33 to a predetermined surface of each of the substrates, followed by baking.
Further, the liquid crystal layer 34 is sealed by forming a liquid crystal encapsulating layer and then performing vacuum degassing. The liquid crystal layer 34 is, for example, a guest-host liquid crystal mixed with a black dye, which is a liquid crystal manufactured by Merck and has a trade name of ZL12327, and is mixed with 4.5% of an optically active substance manufactured by Merck and has a trade name of S811. Was used.

The reflection type liquid crystal display device 10 having such a configuration is
When a voltage is applied to the pixel electrode and the counter electrode,
The reflectance in the normal direction of the glass substrate to light incident at an angle of 30 ° was about 20%, the contrast ratio was 5, no interference color was observed, and a good white display was obtained.

In the reflection type liquid crystal display device 10 of this embodiment,
The picture element electrode 19 of the reflection type active matrix substrate 20
Is formed so as to face the liquid crystal layer 34 side, parallax is eliminated, and a good display screen is obtained.

In this embodiment, since the pixel electrodes 19 of the reflection type active matrix substrate 20 are arranged on the liquid crystal layer 34 side, that is, at positions substantially adjacent to the liquid crystal layer 34, the projections 14a and 14b are formed. It is desirable that the height of the liquid crystal layer 34 is not smaller than the thickness of the cell, and that the inclination angles of the projections 14a and 14b are gentle enough not to disturb the orientation of the liquid crystal layer 34.

Further, although the glass substrate 11 is used as the insulating substrate in this embodiment, the same effect can be obtained with an opaque substrate such as a Si substrate. In this case, there is an advantage that the circuit can be integrated on the glass substrate 11.

In the above embodiment, the phase change type guest / host mode is taken as the display mode, but the present invention is not limited to this. For example, other light absorption modes such as a two-layer guest host, a light scattering type display mode such as a polymer dispersed type LCD, and a birefringence display mode used in a ferroelectric LCD. The reflection type active matrix substrate 20 and the method for manufacturing the same can be applied.

In the above embodiment, T is used as the switching element.
Although the FT 21 is used, the present invention is not limited to this, and other switching elements, for example, MIM (Metal-Ins
(Ultra-Metal) elements, diodes, varistors and the like.

[0053]

As described in detail above, in the present invention,
Since the picture element electrode having the reflection function is formed in a continuous wave shape, the wavelength dependence can be reduced, and a display having a good white surface without interference colors can be performed. Also, when the convex portion is formed by an optical method using a photomask,
The projections can be formed with good reproducibility, and the upper surface of the pixel electrode obtained by this can also have good reproducibility.

[Brief description of the drawings]

FIG. 1 is a plan view showing a reflection type active matrix substrate of the present embodiment.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view showing a step of forming the picture element electrode in FIG. 1;

FIG. 4 is a plan view showing a photomask used when manufacturing the reflection type active matrix substrate of this embodiment.

FIG. 5 is a diagram showing a method for measuring the reflection characteristics of a picture element electrode having a light reflection function.

FIG. 6 is a conceptual diagram showing the occurrence of optical interference.

FIG. 7 is a cross-sectional view of the picture element electrodes of Comparative Examples 1 and 2.

FIG. 8 is a view showing the wavelength dependence of the picture element electrode of the present embodiment.

FIG. 9 is a graph showing the wavelength dependence of the pixel electrodes of Comparative Examples 1 and 2.

FIG. 10 is a sectional view showing a reflective liquid crystal display device according to the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Reflection type liquid crystal display device 11 Glass substrate 12 Resist film 13 Photomask 13a Pattern hole 13b Pattern hole 14a ', 14b' Convex part 14a, 14b Convex part cut off 15 Polymer resin film 19 Pixel electrode 20 Reflective active matrix substrate 21 TFT (thin film transistor) 22 Gate bus line 23 Gate electrode 24 Source bus line 25 Source electrode 26 Drain electrode 27 Semiconductor layer 28 Contact layer 29 Contact hole 30 Counter electrode 31 Complementary color filter plate 32 Transparent electrode 33 Liquid crystal alignment Film 34 liquid crystal layer

Continuation of the front page (56) References JP-A-58-136085 (JP, A) JP-A-57-70585 (JP, A) JP-A-58-2821 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) G02F 1/1343 G02F 1/136

Claims (3)

(57) [Claims] 1. A material having a light reflecting function on an insulating substrate.
Pixel electrodes made of a material are arranged in a matrix,
A reflective actuated electrode with a continuous wavy upper surface.
A method of manufacturing a passive matrix substrate, wherein at least two or more
Forming a raised convex portion, and forming a continuous wavy surface on the substrate on which the convex portion is formed.
Forming a polymer resin film having a surface, comprising a material having a light reflecting function on the polymer resin film
Forming a picture element electrode . 2. A material having a light reflecting function on an insulating substrate.
Pixel electrodes made of a material are arranged in a matrix,
A reflective actuated electrode with a continuous wavy upper surface.
A method of manufacturing a passive matrix substrate, wherein at least two or more
Forming a raised convex portion using a polymer resin, and subjecting the substrate on which the convex portion is formed to heat treatment to form the convex portion
Of softening the polymer resin to be formed and rounding the corners of the convex portion
And a picture element electrode made of a material having a light reflecting function on the convex portion
Forming a reflective active matrix substrate. 3. A material having a light reflecting function on an insulating substrate.
Pixel electrodes made of a material are arranged in a matrix,
A reflective actuated electrode with a continuous wavy upper surface.
A method for manufacturing a passive matrix substrate, wherein at least two or more diameters are different
Use a photomask in which rounded circles are randomly arranged
And at least two convex portions with different heights
Forming step and a picture element electrode made of a material having a light reflecting function on the convex portion
Forming a reflective active matrix substrate.