TWI787412B - Black matrix substrate and display device with black matrix substrate - Google Patents

Abstract

The black matrix substrate of the present invention is provided with: a transparent substrate; a semi-transmissive film formed on the aforementioned transparent substrate; A plurality of first openings are provided on the semi-transmissive film; a transparent resin layer is formed on the semi-transmissive film to cover the first black matrix layer; and a second black matrix layer is formed on the transparent resin layer and having a plurality of second openings; in a plan view viewed from a surface opposite to the surface of the transparent substrate on which the semi-transmissive film is formed, the semi-transmissive film is combined with the plurality of first openings and The first black matrix layers overlap, and the positions of the plurality of second openings correspond to the positions of the plurality of first openings in a plan view.

Description

Black matrix substrate and display device with black matrix substrate

The present invention relates to a black matrix substrate used in a liquid crystal display device, a micro LED (LED display), an organic EL display device, and the like, and further relates to a display device provided with a black matrix substrate.

A liquid crystal display device is a display device that uses LED (Light Emitting Diode) as a backlight as a light source, and uses liquid crystal as a display function layer that switches between light transmission and non-transmission.

In recent years, attention has been drawn to the technology of using direct-lit backlights called Mini LEDs (submillimeter light-emitting diodes) in liquid crystal display devices. The Mini LEDs have a plurality of LED chips with a size of about 5 μm to 100 μm arranged in a matrix. made up of. In Mini LED, generally, three types of LED chips that emit red light, green light, and blue light are used.

In addition, local dimming technology that locally adjusts the luminance of the three types of LED chips or partially stops light emission in response to the position of the display part on the display screen has attracted attention.

In the liquid crystal display device using such local dimming, since the light emission of the display screen can be partially turned off (off), the contrast of the display can be greatly improved. In conventional liquid crystal display devices, since the backlight is always turned on, slight light leakage occurs when the liquid crystal is displayed in black, and it is difficult to obtain the same contrast as that of organic EL.

A micro LED (micro LED) is a display device in which LED chips with a size of about 2 μm to 50 μm are arranged in a matrix structure, and each of a plurality of LED chips is individually driven to perform display. Such micro-LEDs can be displayed without the use of liquid crystals.

The micro LED system can be roughly divided into: the same as the above-mentioned Mini LED, using three types of LED chips that emit red light, green light, and blue light; and light-emitting LED chips that use only light that emits light in the wavelength range from blue to near ultraviolet Such as monochromatic light-emitting LED chips. In micro-LEDs, each LED chip plays the role of a display function layer.

In the method using a single-color light-emitting LED chip, color display is realized by laminating a wavelength conversion element (such as quantum dots, etc.) that performs wavelength conversion on each of a plurality of single-color light-emitting LED chips. Convert the emission wavelength to any one of red, green and blue.

Organic EL is the abbreviation of Organic Electroluminescence. An organic EL display device is a display device that uses the luminescence generated by the recombination of electrons and holes injected into an organic compound to display as a display function layer. Organic EL display devices are broadly classified into: the method using three light-emitting layers that emit red, green, and blue; and the method that combines a color filter with a white light-emitting layer that emits white.

In a liquid crystal display device, a micro LED display device, and an organic EL display device, the linearity of the light emitted from the display function layer toward the pixel opening is not sufficiently obtained. Therefore, stray light (obliquely emitted light) to adjacent pixels is generated, and display contrast is lowered.

In particular, as the pixel size continues to be miniaturized, the decrease in display contrast due to stray light will become a problem. In addition, when the display device is used in a bright environment, a decrease in display contrast due to incident light entering the display device from the outside becomes a problem.

In an organic EL display device or a micro LED, a circular polarizing plate is used in order to avoid a decrease in contrast caused by incident light entering the display device from the outside. In organic EL display devices or micro LEDs, circular polarizers are mounted on top of the display devices in order to eliminate external light reflections generated by light-reflective pixel electrodes and improve visibility. However, since the circular polarizing plate is expensive, it is strongly requested to omit the circular polarizing plate in terms of the structure of the display device.

Patent Document 1 discloses a two-layer black matrix (see FIG. 1 ). However, the technique of Patent Document 1 is a technique for displaying a stereoscopic image to a naked-eye observer. Patent Document 1 does not address the reduction in contrast in a display device using various display function layers. Patent Document 1 does not propose a configuration that omits an expensive circular polarizing plate, and also does not disclose a technique for suppressing surface reflection of a black matrix.

Patent Document 2 describes a color filter using a first light-shielding layer and a second light-shielding layer. However, Patent Document 2 does not propose a configuration that omits an expensive circular polarizing plate, and also does not disclose a technique for suppressing surface reflection of the first light-shielding layer. Furthermore, in micro LEDs including red light emitting elements, green light emitting elements, and blue light emitting elements, color filters are not required. Also, similarly, an organic EL display device with improved color purity does not require color filters. Even in liquid crystal display devices, red light, green light, and blue light of the LED backlight are sequentially lit to display In the field sequential (field sequential), no color filter is required. Patent Document 2 does not consider a configuration without color filters.

However, in Patent Document 2, the feature that the second light-shielding layer covers the end of the colored layer and the feature of the width of the second light-shielding layer in Claim 3 are similar to the color filter shown in FIG. 16 of Patent Document 1. The pieces are roughly the same. Patent Document 1 also describes the subject of alignment between the first light-shielding layer and the second light-shielding layer. The technology related to paragraphs [0034] to [0036] of the second light-shielding layer of Patent Document 2 is also described in, for example, paragraph [0105] of Patent Document 1.

prior art literature patent documents

Patent Document 1 Japanese Patent No. 5804196

Patent Document 2 Japanese Patent No. 6225524

The present invention is made in view of the above-mentioned conventional technologies or problems, and provides a display device that can improve display contrast in display devices such as liquid crystal display devices, micro LED (LED displays), and organic EL display devices that further require high definition. A black matrix substrate, and a display device with a black matrix substrate.

The black matrix substrate of the first aspect of the present invention comprises: a transparent substrate; a semi-transmissive film formed on the aforementioned transparent substrate; The transmissive film is formed on the aforementioned semi-transmissive film in a contact manner, and has a plurality of first openings; a transparent resin layer is formed on the aforementioned semi-transmissive film to cover the aforementioned first black matrix layer; and a second black matrix layer , is formed on the aforementioned transparent resin layer, and has a plurality of second openings; in a plan view viewed from a surface opposite to the surface of the aforementioned transparent substrate on which the aforementioned semi-transmissive film is formed, the aforementioned semi-transmissive film is the same as the plurality of The plurality of first openings overlaps with the first black matrix layer, and the positions of the plurality of second openings correspond to the positions of the plurality of first openings in plan view.

In the black matrix substrate of the first aspect of the present invention, the semi-transmissive film may contain carbon as a pigment, and the transmittance of the semi-transmissive film to visible light is in the range of 98% to 60%.

In the black matrix substrate according to the first aspect of the present invention, the semi-transmissive film may be a dispersion having carbon, optically isotropic fine particles, and a resin in which the carbon and the fine particles are dispersed.

In the black matrix substrate of the first aspect of the present invention, the fine particles may be fine particles of silicon dioxide.

In the black matrix substrate of the first aspect of the present invention, the total solid content of the resin, the carbon, and the fine particles is set to 100% by mass, and the amount of the carbon is within the range of 0.5% by mass to 15% by mass, The amount of the aforementioned fine particles is in the range of 1% by mass to 30% by mass.

In the black matrix substrate of the first aspect of the present invention, the line width of the second black matrix layer may be smaller than the line width of the first black matrix layer.

In the black matrix substrate of the first aspect of the present invention, the second black matrix layer may have light transmittance in the near-infrared region.

Each of the plurality of first openings of the first black matrix layer may have a colored layer.

In the black matrix substrate of the first aspect of the present invention, the colored layer may be a red layer, a blue layer, and a green layer, and in a manner corresponding to three first openings of the plurality of first openings, The red layer, the green layer, and the blue layer are provided in the first opening.

The display device of the second aspect of the present invention comprises: the black matrix substrate of the above-mentioned first aspect; a display function layer; and an array substrate having a plurality of active elements.

The present invention can provide a black matrix substrate capable of improving display contrast and a display device equipped with a black matrix substrate in display devices such as liquid crystal display devices, micro LED (LED displays), and organic EL display devices that require further high-definition .

10‧‧‧Semi-transmissive film

11‧‧‧The first black matrix layer (black matrix layer)

12‧‧‧The second black matrix layer (black matrix layer)

13‧‧‧fine particles

21‧‧‧The first transparent resin layer

22‧‧‧The second transparent resin layer

43‧‧‧surface

47‧‧‧4th insulating layer

49‧‧‧6th insulating layer

55‧‧‧gate electrode

56‧‧‧Drain electrode

58‧‧‧channel layer

68‧‧‧Thin Film Transistor

75‧‧‧Auxiliary conductor

76‧‧‧Transparent conductive film

77‧‧‧joining layer

80‧‧‧Organic EL layer

88‧‧‧lower electrode

90‧‧‧n-type semiconductor layer

91‧‧‧p-type semiconductor layer

93‧‧‧contact hole

94‧‧‧embankment

95‧‧‧The second planarization layer

96‧‧‧The first planarization layer

148‧‧‧The third insulating layer

156‧‧‧Drain electrode

189‧‧‧lower electrode

191‧‧‧Hole injection layer

248‧‧‧5th insulating layer

750‧‧‧Micro LED display devices

850‧‧‧Organic EL display device

903‧‧‧Backlight unit

904‧‧‧Cover glass

950‧‧‧LCD display device

87, 187‧‧‧upper electrode

92, 192‧‧‧luminescent layer

102, 310‧‧‧Transparent substrate

109, 195‧‧‧Sealing layer

205, 305‧‧‧pixel opening

202, 302, 802‧‧‧substrate

150, 300, 550, 650‧‧‧black matrix layer

250, 350, 750, 850‧‧‧display device

201, 301, 501, 801, 901‧‧‧array substrate

102T‧‧‧outside

11S‧‧‧1st pixel opening

12S‧‧‧2nd pixel opening

31, 89, 121‧‧‧Reflective electrode

32, 122, CHIP‧‧‧Light-emitting components

B‧‧‧blue layer (coloring layer)

BW1, BW2‧‧‧line width

CB‧‧‧blue conversion layer

CF‧‧‧coloring layer

CG‧‧‧Green conversion layer

CR‧‧‧red conversion layer

G‧‧‧green layer (coloring layer)

IL1, IL2, IL3‧‧‧external light

LC‧‧‧liquid crystal layer

R‧‧‧Red layer (coloring layer)

RL1, RL2, RL3‧‧‧reflected light

FIG. 1 is a partial cross-sectional view showing a black matrix substrate according to a first embodiment of the present invention.

Fig. 2 is a plan view showing a black matrix substrate according to the first embodiment of the present invention.

FIG. 3 is a partially sectional view showing a display device including a black matrix substrate according to the first embodiment of the present invention, and is a diagram illustrating one effect obtained by the embodiment of the present invention.

4 is a cross-sectional view partially showing an example of a display device having a conventional black matrix substrate, and is a diagram comparing the black matrix substrate shown in FIG. 3 with a conventional black matrix substrate.

Fig. 5 is a partially sectional view showing a display device including a black matrix substrate according to the first embodiment of the present invention, and is a diagram illustrating one effect obtained by the embodiment of the present invention.

FIG. 6 is a cross-sectional view partially showing an example of a display device having a conventional black matrix substrate, and is a diagram comparing the black matrix substrate shown in FIG. 5 with a conventional black matrix substrate.

7 is a cross-sectional view partially showing Modification 1 of the black matrix substrate according to the first embodiment of the present invention.

Fig. 8 is a cross-sectional view partially showing Modification 2 of the black matrix substrate according to the first embodiment of the present invention.

9 is a cross-sectional view partially showing a display device including a black matrix substrate according to a second embodiment of the present invention.

10 is an enlarged view partially showing members such as thin film transistors provided on the array substrate of the display device including the black matrix substrate according to the second embodiment of the present invention.

11 is a cross-sectional view partially showing a display device including a black matrix substrate according to a third embodiment of the present invention.

12 is a cross-sectional view partially showing a display device including a black matrix substrate according to a fourth embodiment of the present invention.

form for carrying out the invention

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In the following description, the same or substantially the same functions and components are assigned the same symbols, and the description thereof is omitted or simplified, or described only when necessary. In each drawing, since each constituent element is set to be recognizable on the drawing, the size and ratio of each constituent element are suitably different from the actual ones. The number of pixels, the number of pixel openings, and the shape of the pixel openings are not limited by the drawings described below. In addition, in order to explain the embodiments of the present invention easily, the structure of the display device may be described with the number of components constituting the display device reduced in cross-sectional views or plan views. The illustrations of the display function layers constituting the display device, etc. are sometimes simplified.

In each of the embodiments described below, the characteristic parts will be described. For example, descriptions of components used in general display devices that are not different from the display device of this embodiment may be omitted.

In addition, in the description, the term "plan view" refers to a plane view of the plane view of the surface of the transparent substrate on which the semi-transmissive film or black matrix layer is not formed by the observer in the normal direction.

In addition, in the specification, ordinal numbers such as "first" and "second" are added to avoid confusion of constituent elements, and the number is not limited. The first transparent resin layer or the second transparent resin layer may be simply referred to as a transparent resin layer. Moreover, the 1st black matrix layer and the 2nd black matrix layer are sometimes only called a black matrix layer or a black matrix.

In the embodiment of the present invention, in the "display function layer" of the display device, a so-called LED (Light Emitting Layer) can be used. Diode) a plurality of light-emitting diode elements, a plurality of organic EL (organic electroluminescence) elements also called OLED (Organic Light Emitting Diode), or any of a liquid crystal layer.

(first embodiment) (Black Matrix Substrate)

FIG. 1 is a partial cross-sectional view showing a black matrix substrate according to a first embodiment of the present invention.

The black matrix substrate 150 has: a transparent substrate 102; a semi-transmissive film 10 formed on the transparent substrate 102; On the transmissive film 10; the first transparent resin layer 21 (transparent resin layer), is formed on the semi-transmissive film 10 to cover the first black matrix layer 11; the second black matrix layer formed on the first transparent resin layer 21 12; and the second transparent resin layer 22 is formed on the first transparent resin layer 21 so as to cover the second black matrix layer 12 .

That is, the black matrix substrate 150 has a semi-transmissive film 10, a first black matrix layer 11, a first transparent resin layer 21, a second black matrix layer 12, and a second transparent resin layer 22 laminated in sequence on the transparent substrate 102. formed structure.

In FIG. 1, the second transparent resin layer 22 may not be formed.

FIG. 2 is a plan view of the black matrix substrate 150 shown in FIG. 1 , and is a view of the surface of the transparent substrate 102 on which the semi-transmissive film 10 is not formed. That is, FIG. 2 is a plan view of the black matrix substrate 150 viewed from the direction indicated by the symbol OB in FIG. 1 . Therefore, in Figure 2 Among them, the first black matrix layer 11 and the second black matrix layer 12 are overlapped and arranged on the lower part of the semi-transmissive film 10 . The overlapping of the first black matrix layer 11 and the second black matrix layer 12 forms an effective display area when the black matrix substrate 150 is applied to a display device. The semi-transmissive film 10 is formed so as to cover this effective display area in plan view.

(transparent substrate)

As the material of the transparent substrate 102 applicable to the black matrix substrate 150, transparent substrates such as glass substrates, quartz substrates, sapphire substrates, and plastic substrates can be used.

In addition, when the display device is formed by laminating the display functional layer and the array substrate for driving the display functional layer with the black matrix substrate 150 , the substrate materials of each of the array substrate and the black matrix substrate 150 should be the same.

In particular, it is ideal that the thermal expansion coefficient of the substrate material constituting the array substrate is the same as that of the substrate material constituting the black matrix substrate 150 . When different substrate materials are used for the array substrate and the black matrix substrate 150 , from the viewpoint of thermal expansion coefficient, there may be problems such as warpage or peeling of the substrate.

(1st black matrix layer, 2nd black matrix layer)

The first black matrix layer 11 has a plurality of first pixel openings 11S (first openings). The second black matrix layer 12 has a plurality of second pixel openings 12S (second openings).

In a plan view viewed from the surface (the surface indicated by symbol OB) opposite to the surface of the transparent substrate 102 on which the semi-transmissive film 10 is formed, the semi-transmissive film Reference numeral 10 overlaps so as to cover the plurality of first pixel openings 11S and the first black matrix layer 11 . In plan view, the positions of the plurality of second pixel openings 12S correspond to the positions of the plurality of first pixel openings 11S.

(Constituent material of black matrix layer)

The constituent materials of the first black matrix layer 11 and the second black matrix layer 12 may be the same or different. For example, regarding the manufacturing steps of the first black matrix layer 11 and the second black matrix layer 12 , the second black matrix layer 12 is formed by a general photolithography method after the first black matrix layer 11 is formed. Therefore, for example, the transmittance of observation light can be improved by aligning the transparent substrate 102 that can be subjected to a photolithography step.

As a constituent material of the first black matrix layer 11 and the second black matrix layer 12, it is convenient to use a photoresist in which carbon having light-shielding properties is dispersed and soluble in alkali (alkali). The optical density (ΔOD) of the first black matrix layer 11 should just be 2 or more and 4 or less. Also can make the optical density of the 1st black matrix layer 11 be more than 4, but in the structure of embodiment of the present invention, because the 1st black matrix layer 11 overlaps with the 2nd black matrix layer 12, so need not raise the 1st black matrix layer 11. Individual light-shielding properties of the black matrix layer 11 and the second black matrix layer 12 . Carbon is also known as carbon black.

Moreover, the 2nd black matrix layer 12 may have light transmittance to a near-infrared region. In this case, when aligning the transparent substrate 102 in the photolithography step, the near-infrared region may also be used as observation light. Specifically, as the pigment used for the 2nd black matrix layer 12, for example, If red or yellow organic pigments and blue or violet organic pigments are added to transmit near-infrared light, light in the near-infrared region can also be used to align the transparent substrate 102 . When the light-shielding properties of the visible region are obtained using an organic pigment, the addition of carbon to the second black matrix layer 12 can be reduced or removed.

Alternatively, in order to read the alignment mark formed on the end surface of the substrate when the first black matrix layer 11 is formed, EBR (Edge Bead Removal) technology may be used in the coating formation step of the second black matrix layer. EBR is a technique for removing resist bumps at the end (end face) of a substrate that tends to occur during resist coating. For example, by removing only the portion applied to the end of the substrate in the applied second black matrix layer, it is possible to read the alignment mark formed on the end surface when forming the first black matrix layer 11 which is the base.

The particle diameter of the carbon used for the 1st black matrix layer 11 and the 2nd black matrix layer 12 can be set as 10 nm - 100 nm. Preferably it is 20nm to 60nm. In order to uniformly disperse carbon in the resist, it is preferable to use a dispersant with an Sp value (solubility parameter) of, for example, 10 or more. Since carbon is uniformly dispersed in the resist, the dielectric constant of the black matrix layer is likely to decrease, so it is preferable to increase the dispersion of carbon in the resist. By reducing the dielectric constant of the black matrix layer, the black matrix substrate 150 can be effectively applied to a display device having a liquid crystal layer as a display function layer.

(film thickness of black matrix layer)

The film thickness of the black matrix layer applicable to the embodiment of the present invention is not particularly specified, for example, as a standard film thickness, it can be selected from the range of 1 μm to 2 μm.

(Inorganic materials that can be added to the black matrix layer)

Other light-shielding pigments such as titanium black can also be added to the resist of the black matrix. In order to improve the dispersion, fine particles such as titanium oxide, calcium carbonate, and silicon dioxide can also be added to the resist.

(line width of black matrix layer)

The line widths BW1 and BW2 of each of the first black matrix layer 11 and the second black matrix layer 12 may not be particularly specified, but for example, the line width BW2 of the second black matrix layer 12 may also be smaller than that of the first black matrix layer. The line width BW1 of 11, the line width BW2 and the line width BW1 may also be equal.

The black matrix substrate 150 of the embodiment of the present invention is applicable to display devices with high-definition pixels such as 300 ppi or above, and furthermore, 500 ppi or above 2000 ppi. In a display device having high-definition pixels, the aperture ratio of pixels is important. Therefore, it is preferable to form the first black matrix layer 11 so that the line width BW1 becomes as thin as possible. If the line width BW2 of the second black matrix layer 12 is wider than the line width BW1 of the first black matrix layer 11, the aperture ratio of the pixel will decrease, which is not preferable.

The line width BW1, BW2 or film thickness of each of the first black matrix layer 11 and the second black matrix layer 12, or the separation of the first black matrix layer 11 and the second black matrix layer 12 in the thickness direction of the black matrix substrate 150 The distance can be changed by increasing the size or contrast of the screen of the display device.

Or, it is preferable to consider the alignment accuracy of the photolithography step, so that the line width BW2 of the second black matrix layer 12 is larger than that of the first black matrix layer 11. The line width of BW1 is narrow. For example, if the alignment accuracy is ±1.5 μm, then as long as the line width BW2 of the second black matrix layer 12 is compared with the line width BW1 of the first black matrix layer 11, one side is narrower by 1.5 μm (both sides is 3 μm). The line width BW2 of the second black matrix layer 12 is made thinner in consideration of the alignment allowance.

About the film thickness, the film thickness of the 2nd black matrix layer 12 can also be made thinner than the film thickness of the 1st black matrix layer 11. The transmittance of the alkali-soluble photoresist (carbon dispersion to be described later) forming the second black matrix layer 12 can be adjusted. The resist of the second black matrix layer 12 can adjust, for example, the transmittance of the exposure wavelength or the transmittance of the wavelength in the near-infrared region. In the adjustment of the transmittance in the near-infrared region (described later), for example, pigments of opposite colors, such as yellow pigments and purple pigments, which are organic pigments, can be mixed to obtain "black" in the visible region, and the infrared rays of organic pigments can be utilized. The transmittance.

(semi-transmissive film)

The semi-transmissive film 10 is a dispersion having carbon, optically isotropic fine particles, and a resin in which carbon and fine particles are dispersed.

As a material used for the semi-transmissive film 10, substantially the same material as that of the above-mentioned black matrix can be applied. It is preferable to form the semi-transmissive film 10 with a resin dispersion containing carbon as a main pigment. It is preferable to set the transmittance of the semi-transmissive film 10 to visible light in the range of 98% to 60%, and adjust the amount of carbon added to the resin dispersion from the viewpoint of the transmittance.

In micro-LED or organic EL display devices, the lower part of the LED or organic EL layer that is a light-emitting element is often equipped with light reflection sex electrodes. In the micro LED or organic EL display device having such a structure, the re-reflected light of the externally incident light by the light reflective electrode leads to deterioration of visibility. In general, in order to eliminate re-reflected light of externally incident light, an expensive circularly polarizing plate is used in a display device. Alternatively, in most liquid crystal display devices, two polarizing plates (crossed Nicols) (the polarization axes are crossed) are used. When using such a circular polarizing plate or polarizing plate, in order to improve the dispersion or reduce the refractive index of the semi-transmissive film, the change of the polarization state (collapse of polarization) will not occur, and it is preferable to optically isotropic and visible. Transparent inorganic particles in the region are added to the semi-transmissive film.

Optically isotropic fine particles 13 are dispersed in the semi-transmissive film 10 . The optically isotropic microparticles 13 are silica microparticles with a solid content ratio of 18% by mass.

(benzoguanamine)等的樹脂微粒子。 In addition, "optically isotropic" means that the transparent fine particles applicable to the embodiments of the present invention have a crystal structure in which the a-axis, b-axis, and c-axis are equal, or are amorphous, and the transmission of light is not affected by the crystal axes or the crystal structure. influence and is isotropic. Silica fine particles have an amorphous structure (amorphous). As resin fine particles such as resin beads, fine particles having various properties including a refractive index are known, and such fine particles are applicable. Also available in acrylic, styrene, urethane, nylon, melamine, benzoguanidine

(Benzoguanamine) and other resin fine particles.

Microparticles of silicon dioxide (silica) are known as a representative of inorganic fine particles that are optically isotropic and transparent in the visible region. The particle size of the fine particles of silicon dioxide can be selected from the range of, for example, 5nm to 300nm. It is also possible to make transparent in the visible area and have different particle sizes Two or more kinds of inorganic fine particles are dispersed in the semi-transmissive film 10 together with carbon. The combined use of silica fine particles prevents the formation of secondary particles that are likely to be generated in a single carbon, and improves the dispersibility of carbon.

In addition, adding the above-mentioned fine particles 13 to the semi-transmissive film 10 is not for imparting light scattering to the semi-transmissive film 10 . When most scattering films suitable for display devices contain particles, as described in Claim 1 of Patent No. 3531615, particles with an average particle diameter of 1.5 μm to 3.0 μm must be used in micron units. That is, unless particles having a particle size larger than the wavelength of light in the visible region are not used, appropriate light scattering properties cannot be obtained as a scattering film.

In addition, since the refractive index of silicon dioxide is lower than that of carbon, silicon dioxide has the effect of lowering the refractive index of the semi-transmissive film 10 . The semi-transmissive film 10 having a low refractive index suppresses the reflection of light at the interface between the semi-transmissive film 10 and the first black matrix layer 11 and has the effect of improving visibility.

For example, when the light transmittance of the semi-transmissive film 10 is in a high transmittance region such as 98% to 95%, sometimes light reflection at the interface between the first black matrix layer 11 and the semi-transmissive film 10 may be caused by interference. As a result, the first black matrix layer 11 may be slightly colored in some cases. Such slight coloring due to reflected light is easy to be observed in black display when the display of the display device is turned off.

On the other hand, by forming the semi-transmissive film 10 together with silica fine particles and carbon, the effect of preventing such moiré can be obtained. From the viewpoints described above, a semi-transmissive film containing inorganic fine particles that are optically isotropic and transparent in a visible region is useful.

In addition, as shown in the above-mentioned material composition of the second black matrix layer 12, the reflected light of the external light at the interface between the semi-transmissive film containing organic pigments as the main pigment component and the first black matrix layer 11 may appear to be colored. yellow.

In contrast, the semi-transmissive film 10 containing carbon as a main pigment component is flat in reflected light and hardly colored. No change in reflected light means that in the range of the visible region from 400nm to 700nm, for example, in a small range (range) such as 100nm, there is no unevenness (variation) with a transmittance of 2% or more, and it can be expressed as a roughly straight line the transmittance curve.

As a method of forming the semi-transmissive film 10 that can be applied to the embodiment of the present invention, it is preferable to form the semi-transmissive film 10 so that it becomes a full-surface coating film (a flat film with no uneven pattern formed in the effective display area). . Thereby, the semi-transmissive film 10 can be easily formed. The film thickness of the semi-transmissive film 10 is not particularly limited, for example, it can be selected from the range of 0.5 μm to 1.5 μm. A pixel opening may be provided in a part of the semi-transmissive film 10 in accordance with the size of the pixel opening of the display device.

The transmittance of the semi-transmissive film 10 to visible light (typically, the transmittance when the light wavelength is 550 nm) can be selected from the range of 98% to 60%. A semi-transmissive film with a transmittance of more than 99% is prone to ripples caused by the interference of external light reflection as mentioned above, which will damage the display quality of "black display". When the transmittance of the semi-transmissive film is lower than 60%, it is not preferable because the brightness of the display device is lowered. Also, if the transmittance is less than 60%, low reflectance cannot be obtained.

The transmittance of the semi-transmissive film 10 can be adjusted in the range of 98% to 60% according to the film thickness of the semi-transmissive film used on the black matrix substrate.

In addition, the black matrix substrate 150 can obtain a low reflectance of 0.3% to 1% at the interface between the transparent substrate 102 and the semi-transmissive film 10 by including the above-mentioned semi-transmissive film 10 .

If the amount of carbon added to the semi-transmissive film 10 is increased to increase the carbon concentration, the refractive index of the semi-transmissive film 10 will increase, and the reflectance of the semi-transmissive film 10 will increase. When the transmittance of the semi-transmissive film 10 is less than 60%, the refractive index becomes high and the reflectance becomes high.

Regarding the adjustment of the transmittance of the semi-transmissive film 10, when the total solid content of the resin containing the dispersion constituting the semi-transmissive film 10, the optically isotropic fine particles 13, and carbon is 100% by mass, the carbon The amount can be selected from the range of, for example, 0.5% by mass to 15% by mass. A semi-transmissive film having a carbon content of 0.4% by mass or less has a small effect of low reflection and easily generates interference color due to the above-mentioned moiré. When the amount of carbon exceeds 15% by mass, the optical density of the semi-transmissive film increases, making it difficult to obtain a low reflection effect.

Also, when the total solid content containing the above-mentioned resin, fine particles 13, and carbon is taken as 100% by mass, the amount of silica fine particles to be added can be selected from a range of, for example, 1% by mass to 30% by mass. When the silica fine particles are 1% by mass or less, interference colors due to moiré are likely to occur. When the added amount of carbon and silica fine particles exceeds 45% by mass, and further exceeds 50% by mass, the coating suitability of the resist described later is likely to decrease. If the amount of carbon and silica fine particles added is too small, desired characteristics cannot be obtained on the semi-transmissive film.

As the alkaline soluble resin applicable to the resist used for forming the semi-transmissive film 10 or the black matrix layers 11 and 12, for example, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, Alkyl acrylate or methacrylate of ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, etc., cyclic cyclohexyl acrylate or methacrylate, hydroxyethyl acrylate (hydroxyethyl acrylate) or methacrylate, styrene, etc. 1 to 5 monomers selected, and resins synthesized with a molecular weight of about 5,000 to 100,000 can be used. In addition, general photopolymerizable resins, such as epoxy (meth)acrylate, etc. can also be used. Cardo resin excellent in patterning properties and heat resistance can also be used.

As the photopolymerization initiator suitable for the resist used to form the semi-transmissive film 10 or the black matrix layers 11 and 12, conventionally known compounds can be used, but oxime ester compounds are preferably used, It can also achieve high sensitivity when used in a black photosensitive resin composition that does not transmit light.

Solvents used for the resist used in forming the semi-transmissive film 10 or the black matrix layers 11 and 12 include, for example, methanol, ethanol, ethyl cellosolve, and ethyl cellosolve acetate. , diglyme, cyclohexanone, ethylbenzene, xylene, isoamyl acetate, n-pentyl acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate (propylene glycol monomethyl ether) glycol monomethyl ether acetate), propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol Glycol Monoethyl Ether B Ester, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monomethyl ether acetate , triethylene glycol monoethyl ether, triethylene glycol monoethyl ether acetate, liquid polyethylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether, Propylene glycol monoethyl ether acetate, lactate, ethyl ethoxypropionate, etc.

Furthermore, a surfactant for improving the applicability of the resist, a silane coupling agent for improving the adhesion of the resist to the substrate, and the like may be used in combination.

(Effect 1 obtained by using the black matrix substrate of the present embodiment)

FIG. 3 is a partial cross-sectional view of a display device 250 including a black matrix substrate 150 according to the first embodiment of the present invention, and is a diagram illustrating an effect obtained by the embodiment of the present invention.

The display device 250 shown in FIG. 3 is formed by laminating the black matrix substrate 150 and the array substrate 201 in a face-to-face manner.

The black matrix substrate 150 has the structure described with reference to FIGS. 1 and 2 . The array substrate 201 includes: a substrate 202 ; a plurality of reflective electrodes 121 formed on the substrate 202 ; a light-emitting element 122 such as an organic EL formed on each of the plurality of reflective electrodes 121 ; and an active element connected to the reflective electrodes 121 . On the array substrate 201 , active elements are arranged in a matrix, which is omitted in FIG. 3 .

FIG. 4 is a partial cross-sectional view of a display device 350 having a conventional black matrix substrate 300 , and is a diagram comparing the black matrix substrate 150 shown in FIG. 3 with the conventional black matrix substrate 300 .

The black matrix substrate 300 is different from the black matrix substrate 150 shown in FIGS. 1 and 2 in that no semi-transmissive film is formed on the transparent substrate 310 and has a structure in which a black matrix layer 30 is formed on the transparent substrate 310 . The array substrate 301 includes: a substrate 302 ; a plurality of reflective electrodes 31 formed on the substrate 302 ; a light-emitting element 32 such as an organic EL formed on each of the plurality of reflective electrodes 31 ; and an active element connected to the reflective electrodes 31 . Active elements are arranged in a matrix on the array substrate 301 , which is omitted in FIG. 4 .

In the following description referring to FIG. 3 and FIG. 4 , the light reflectance of the reflective electrodes 121 and 31 is set to 100%, presumably on the premise that parallel light is generated from the reflective electrodes 121 and 31 (the generation of diffused light is not considered). 3 and 4 both illustrate the configuration without using a polarizing plate, and describe the case where the reflection component on the surface of the transparent substrate is not included. In order to illustrate reflected light, components such as polarizers are simplified.

In addition, the transmittance described below is the transmittance of visible light (400nm~700nm) using a microspectrometer when a transparent substrate such as glass is used as a reference (reference).

In FIG. 3 , external lights IL1 and IL2 are incident from the upper surface of the display device 250 (in the direction shown by symbol OB in FIG. 1 ). For example, when the light transmittance of the semi-transmissive film 10 is 70%, the amount of external light IL1 passing through the pixel opening 205 is reduced by the semi-transmissive film 10 , and reaches the reflective electrode 121 at 70%. This light is reflected by the reflective electrode 121, The reflected light RL1 is generated, and the reflected light RL1 is transmitted through the semi-transmissive film 10 . The light quantity of the reflected light RL2 transmitted through the semi-transmissive film 10 becomes 49% with respect to the light quantity (100%) of the external light IL1, and the reflected light can be suppressed by the semi-transmissive film 10 .

By setting the transmittance of the semi-transmissive film 10, the amount of reflected light can be suppressed to obtain the desired visibility. The transmittance of the semi-transmissive film 10 can also be adjusted according to the luminous intensity of the light emitting element 122 . In addition, although not shown in FIG. 3 , the light that enters the inside from the outside of the display device 250 in a direction oblique to the outer surface 102T of the transparent substrate 102 is reflected in the first black matrix layer 11 and the second black matrix layer 11 . The laminate configuration of the matrix layer 12 is cut. Therefore, an effect more excellent than the above-mentioned suppression of re-reflected light can be obtained, and visibility can be greatly improved.

In contrast, in the display device 350 provided with the conventional black matrix substrate 300 shown in FIG. 4 , no semi-transmissive film is formed, so the external light IL3 passing through the pixel opening 305 is not reduced in light quantity. When it reaches the reflective electrode 31, it is reflected by the reflective electrode 31 as it is, and the reflected light RL3 having a light quantity of 100% is generated without reducing the quantity of light.

Moreover, external light IL2 incident on the first black matrix layer 11 shown in FIG. 3 is transmitted so as to reciprocate the semi-transmissive film 10 on the first black matrix layer 11, and the light is absorbed. Thereby, for example, the reflectance can be suppressed to 1% or less.

In contrast, in the case of the black matrix substrate 300 without the semi-transmissive film shown in FIG. 4 , the reflectance at the interface between the black matrix layer 30 and the transparent substrate 310 is usually about 3%. In the configuration including the semi-transmissive film 10 shown in FIG. 3 , the reflectance at the interface between the first black matrix layer 11 and the transparent substrate 310 is 1/3 or less of the conventional one.

(Effect 2 obtained by the black matrix substrate of this embodiment)

5 is a partial cross-sectional view of a display device 250 including a black matrix substrate 150 according to the first embodiment of the present invention, and is an explanatory view of an effect obtained by the embodiment of the present invention. The display device 250 shown in FIG. 5 corresponds to FIG. 3 , so the description of the structure of the display device 250 is omitted.

FIG. 6 is a partial cross-sectional view of a display device 350 including a conventional black matrix substrate 300 , and is a diagram comparing the black matrix substrate shown in FIG. 5 with a conventional black matrix substrate. The display device 350 shown in FIG. 6 corresponds to FIG. 4 , so the description of the structure of the display device 350 is omitted.

5 and 6 are explanatory diagrams illustrating the influence of light on adjacent pixels when the light emitting elements 122 and 32 emit light.

In FIG. 5 and FIG. 6 , the light emitting elements 122 and 32 are simplified and illustrated elements of micro LEDs (LED light emitting elements), organic EL elements, or Mini LEDs used as backlights.

In FIG. 5 , the emitted lights emitted from the light emitting element 122 are represented by symbols E10 , E11 , E12 , E13 , and E14 . In FIG. 6 , the light emitted from the light emitting element 32 is represented by symbols E20, E21, E22, E23, and E24.

The emitted light indicated by symbols E10 , E11 , and E13 in FIG. 5 does not affect adjacent pixels, but passes through the pixel opening 205 and is properly emitted to the outside of the display device 250 to play a display role.

Similarly, the emitted light represented by symbols E20, E21, and E23 in FIG. 6 does not affect adjacent pixels, but passes through the pixel opening 305, and is properly emitted to the outside of the display device 350 to play a display role.

When light enters the inside of the display device 250 from the outside in an oblique direction with respect to the outer surface 102T of the transparent substrate 102, in the case of both the incident light and the light reflection, the first display shown in FIG. 2. The black matrix layer 12 can obtain the effect of suppressing re-reflection. Even when the transmittance of the semi-transmissive film 10 is as high as 55% or more, the effect of suppressing reflected light can be obtained above the calculated value.

Although not shown in FIG. 6 , it can be understood that if it is assumed that, for example, a liquid crystal layer is used as a display function layer, and the light emitting element 32 is a Mini LED (submillimeter light emitting diode) provided in the backlight, then the light generated by the light emitting element 32 The emitted light E22 and E24 enter adjacent pixels in the form of stray light, which reduces the display contrast.

It can be understood that even if the light-emitting element 32 shown in FIG. 6 is a micro-LED or an organic EL light-emitting layer, since the conventional black matrix substrate 300 is used, the emitted light E22 and E24 generated from the light-emitting element 32 are similarly Entering adjacent pixels in the form of stray light, the display contrast will be reduced.

In contrast, it can be understood that in the display device 250 provided with the black matrix substrate 150 of the first embodiment of the present invention shown in FIG. ), stray light will not affect adjacent pixels.

(Modification 1)

Fig. 7 is a cross-sectional view partially showing Modification 1 of the black matrix substrate according to the embodiment of the present invention. The black matrix substrate 550 shown in FIG. 7 is different from the black matrix substrate 150 shown in FIG. 1 in that the semi-transmissive film 10 uses a semi-transmissive film to which no optically isotropic fine particles 13 are added.

According to such a black matrix substrate 550, not only the same effect as that of the above-mentioned first embodiment cannot be obtained, but also because the microparticles 13 are not added to the semi-transmissive film 10, the structure of the semi-transmissive film 10 is simple, which contributes to the stability of the black matrix substrate. Reduce costs.

(Modification 2)

Fig. 8 is a cross-sectional view partially showing Modification 2 of the black matrix substrate according to the embodiment of the present invention. The black matrix substrate 650 shown in FIG. 8 is different from the black matrix substrate 150 shown in FIG. 1 in that the colored layers of the red layer R, the green layer G, and the blue layer B are provided.

Each of the plurality of first pixel openings 11S of the first black matrix layer 11 has a colored layer CF. The colored layer CF is composed of a red layer R, a green layer G and a blue layer B. The red layer R, the green layer G, and the blue layer B are provided in the first pixel opening 11S so as to correspond to the three first pixel openings 11S.

In particular, the red layer R, the green layer G, and the blue layer B are provided in the first pixel opening 11S of the first black matrix layer 11 between the first transparent resin layer 21 and the semi-transmissive film 10 . That is, the black matrix substrate 650 is a black matrix substrate (color filter substrate) on which a colored layer CF is added.

According to such a black matrix substrate 650, not only the same effect as that of the above-mentioned first embodiment can be obtained, but also a black matrix substrate having a function as a color filter substrate can be realized.

(display device)

The display function layer constituting the display device to which the black matrix substrates 150, 550, 650 of the first embodiment, modification 1, and modification 2 described above can be selected from a liquid crystal layer, an organic EL element, and a micro LED element. The display function layer is driven by a plurality of thin film transistors (active elements) called TFTs arranged in a matrix on the array substrate.

Hereinafter, the display device according to the embodiment of the present invention will be described, but the illustration of the thin film transistor will be omitted. In addition, the same members as those of the first embodiment, modification 1, and modification 2 are denoted by the same reference numerals, and description thereof will be omitted or simplified.

(Second Embodiment) (Micro LED display device)

9 is a view showing a display device according to a second embodiment of the present invention, and is a partial cross-sectional view of a micro LED display device 750 to which a black matrix substrate 550 according to Modification 1 of the first embodiment is applied.

FIG. 10 is an enlarged view partially showing the array substrate 501 included in the micro LED display device 750 according to the second embodiment, and is a diagram showing the position of the thin film transistor 68 .

A fourth insulating layer 47 is formed on the surface 43 of the array substrate 501 . On the 4th insulating layer 47, laminated in sequence: to cover the thin The third insulating layer 148 formed by means of the film transistor 68, the fourth insulating layer 47, and the thin film transistor 68; the gate electrode formed on the third insulating layer 148 in a manner facing the channel layer 58 of the thin film transistor 68 electrode 55 ; sixth insulating layer 49 formed to cover third insulating layer 148 and gate electrode 55 ; and first planarization layer 96 formed to cover sixth insulating layer 49 .

On the first planarizing layer 96 , the sixth insulating layer 49 and the third insulating layer 148 , a contact hole 93 is formed at a position corresponding to the drain electrode 56 of the thin film transistor 68 . Also, on the first planarization layer 96 , a bank 94 is formed at a position corresponding to the channel layer 58 (see FIG. 10 ). The area between the banks 94 adjacent to each other in the cross-sectional view, that is, the area surrounded by the banks 94 in the plan view, covers the top of the first planarization layer 96, the inside of the contact hole 93, and the drain electrode 56. A reflective electrode 89 (pixel electrode) is formed in this manner. In addition, the reflective electrode 89 may not be formed on the upper surface of the bank 94 . The reflective electrode 89 is electrically connected to the lower electrode 88 of the light emitting element CHIP via the conductive bonding layer 77 .

The second planarization layer 95 is formed so as to bury the inside of the contact hole 93 and to cover the reflective electrode 89 and the light emitting element CHIP. A transparent conductive film 76 called ITO (Indium Tin Oxide) is formed on the second planarization layer 95 , and an upper electrode 87 constituting the light emitting element CHIP is connected to the transparent conductive film 76 . Furthermore, an auxiliary conductor 75 is formed on the transparent conductive film 76 , and the transparent conductive film 76 is electrically connected to the auxiliary conductor 75 . Furthermore, a sealing layer 109 (adhesive layer) is formed on the surface of the transparent conductive film 76 so as to cover the auxiliary conductor 75 . The auxiliary conductor 75 is a conductor for reducing the resistance value of the transparent conductive film 76 in plan view.

As a material of the bank 94, organic resins such as acrylic resins, polyimide resins, and novolak resins can be used. In the embankment 94, inorganic materials such as silicon oxide and silicon oxynitride may be further laminated.

As materials for the first planarization layer 96 and the second planarization layer 95 , acrylic resin, polyimide resin, benzocyclobutene resin, polyamide resin, and the like can also be used. Low dielectric constant materials (low-k materials) may also be used.

The light-emitting element CHIP has a structure in which an upper electrode 87 , an n-type semiconductor layer 90 , a light-emitting layer 92 , a p-type semiconductor layer 91 , and a lower electrode 88 are sequentially laminated. In other words, the light-emitting element CHIP has a configuration in which p-type semiconductor layer 91 , light-emitting layer 92 , n-type semiconductor layer 90 , and upper electrode 87 are sequentially stacked on lower electrode 88 . As shown in FIG. 10 , the electrodes for the LED to emit light are formed on different surfaces, and are formed on surfaces facing each other. In addition, the upper electrode 87 and the lower electrode 88 are arranged outside the surface facing each of the n-type semiconductor layer 90 and the p-type semiconductor layer 91 stacked in parallel to each other. The light emitting element CHIP having such a structure is called a vertical light emitting diode in this embodiment. In the cross-sectional view, when the LED structure is irregular such as a pyramid shape, it is not included in the vertical light-emitting diode of the present invention. Among LED structures, a structure in which electrodes are arranged on one side or a structure in which electrodes are arranged in a horizontal direction is called a horizontal light emitting diode.

For color display, LED elements (miniature LEDs) that emit red, green, or blue light can be used as light-emitting elements CHIP. This kind of LED emits light, because the color purity of red, green and blue is extremely high, so color filters can be omitted. Alternatively, a matrix of one type of LED element emitting light in a wavelength range from blue to near ultraviolet may also be used. In this case, color display can be performed using a layer of three types of quantum dots that convert the wavelength of light emitted from the LED element in the blue to near-ultraviolet wavelength range into red, green, and blue in the visible range.

The shape of the light-emitting element CHIP is, for example, a square shape with a side length of 2 μm to 50 μm in plan view. However, shapes other than square or rectangle are also applicable. Alternatively, the size of one side may be set to 50 μm or more. In addition, in a plan view, one or two or more light-emitting elements can be mounted on each pixel, and redundancy can be provided. In mounting the light-emitting element CHIP, for example, the orientation of the square-shaped light-emitting element CHIP can be randomly rotated in units of 90 degrees and mounted. By random installation, it can reduce the color spot and brightness unevenness of the whole screen caused by the slight deviation of LED crystal growth.

The bonding layer 77 is used to weld the lower electrode 88 and the reflective electrode 89 of the light-emitting element CHIP within a temperature range of, for example, 150°C to 340°C, and a conductive material capable of electrical connection can be used. Here, as the conductive material, conductive fillers such as silver, carbon, graphite, etc. may be dispersed in a thermally fluid resin. Alternatively, In (indium), InBi alloy, InSb alloy, InSn alloy, InAg alloy, InGa alloy, SnBi alloy, SnSb alloy, etc., or a ternary or quaternary system of these metals may be used for the bonding layer 77. low melting point metals. Alternatively, a material having electrical conductivity may be used only in the thickness direction of the anisotropic conductive film.

(third embodiment) (Organic EL display device)

11 is a view showing a display device according to a third embodiment of the present invention, and is a cross-sectional view partially showing an organic EL display device 850 to which a black matrix substrate 650 according to Modification 2 of the first embodiment is applied.

The organic EL display device 850 is constructed by bonding the black matrix substrate 650 and the array substrate 801 including the organic EL layer 80 face to face. The organic EL layer 80 is an organic electroluminescent light-emitting layer that emits blue light. The black matrix substrate 650 includes color conversion layers such as a red conversion layer CR, a green conversion layer CG, and a blue conversion layer CB. The color conversion layer is a conversion layer that converts blue luminescence (may also include near-ultraviolet region) into light with a longer wavelength than this luminescence wavelength, such as red, green and blue light. The material system of the color conversion layer may suggest inorganic phosphors, fluorescent dyes, quantum dots and the like.

A color filter may also be inserted between the color conversion layers (the red conversion layer CR, the green conversion layer CG, and the blue conversion layer CB) and the semi-transmissive film 10 . In the color conversion layer, a configuration in which the blue conversion layer CB is omitted may also be employed. In addition, in an organic EL display device in which the color purity of luminescent colors is being improved, it is possible to remove the color conversion layer and arrange color filters such as red, green, and blue.

Next, the structure of the organic EL display device 850 will be described.

As the substrate 802 of the array substrate 801, it is not necessary to be limited to a transparent substrate. For example, as an applicable substrate, a glass substrate, a ceramic substrate, etc. Substrates, quartz substrates, sapphire substrates, semiconductor substrates such as silicon, silicon carbide or silicon germanium, or plastic substrates.

The fourth insulating layer 47 is formed on the substrate 802 of the array substrate 801 . On the fourth insulating layer 47, a thin film transistor (not shown), a fifth insulating layer 248 formed to cover the fourth insulating layer 47 and the thin film transistor, and a channel layer of the thin film transistor are stacked sequentially. The gate electrode formed on the fifth insulating layer 248 in a facing manner, the sixth insulating layer 49 formed to cover the fifth insulating layer 248 and the gate electrode, and the first insulating layer formed on the sixth insulating layer 49 planarization layer 96 .

In addition, as the thin film transistor formed on the substrate 802, the thin film transistor 68 having the structure shown in FIG. 10 can also be used.

In the first planarization layer 96 , the sixth insulating layer 49 and the fifth insulating layer 248 , contact holes are formed at positions corresponding to the drain electrodes of the thin film transistors. Also, on the first planarization layer 96 , banks 94 are formed at positions corresponding to the channel layer. In the area between the banks 94 adjacent to each other in the cross-sectional view, that is, in the area surrounded by the banks 94 in the plan view, to cover the upper surface of the first planarization layer 96, the inside of the contact hole 93 and the drain electrode 156 The lower electrode 189 (pixel electrode) is formed in such a manner. In addition, the lower electrode 189 may not be formed on the upper surface of the bank 94 .

Furthermore, the hole injection layer 191 is formed so as to cover the lower electrode 189 , the bank 94 and the first planarization layer 96 . On the hole injection layer 191, a light emitting layer 192, an upper electrode 187, and a sealing layer 195 are laminated in this order.

The lower electrode 189 (reflective electrode) has a structure in which silver or silver alloy layers are sandwiched by conductive oxide layers as will be described later.

The lower electrode 189 may also have a three-layer laminate structure in which a silver alloy layer is sandwiched between conductive metal oxide layers. It is also possible to apply the above-mentioned composite oxide layer to the conductive metal oxide layer, and set the film thickness of the silver alloy layer, for example, within the range of 100nm to 250nm or a film thickness of 300nm or more. 3-layer laminate structure sandwiching silver alloy layers. In this case, the lower electrode 189 having a high reflectance to visible light can be realized. For example, it is also possible to set the film thickness of the silver alloy layer within a range of, for example, 9 nm to 15 nm, and use a three-layer laminate film having visible light transmittance as the upper electrode. Moreover, the composite oxide of indium oxide or zinc oxide is mentioned as an electroconductive metal oxide system. Regarding ITO (a mixed oxide containing indium oxide and tin oxide), which is a representative conductive oxide, the oxide is more corrosion-resistant (noble) than the silver alloy layer (or copper alloy layer). Therefore, the silver alloy (or copper alloy layer) is selectively etched, and the three layers tend to have different line widths. Therefore, it is also possible to adjust the corrosion potential by adding soluble oxides such as zinc oxide, gallium oxide, and antimony oxide to indium oxide to form a silver alloy layer (or copper alloy layer) and a mixed oxide layer whose corrosion potential is consistent. A three-layer laminated film in which silver or the like is sandwiched between these conductive metal oxides can be used as electrodes or conductive wiring for micro LEDs or liquid crystal display devices.

As a material of the bank 94, organic resins such as acrylic resins, polyimide resins, and novolak resins can be used. Inorganic materials such as silicon oxide and silicon oxynitride may be further deposited on the embankment 94 .

As the material of the first planarization layer 96, acrylic resin, polyimide resin, benzocyclobutene resin, polyamide resin, etc. can also be used. Low dielectric constant materials (low-k materials) may also be used.

(fourth embodiment) (Liquid Crystal Display Device)

12 is a view showing a display device according to a fourth embodiment of the present invention, and is a cross-sectional view of a liquid crystal display device 950 partially showing a black matrix substrate 650 according to Modification 2 of the first embodiment.

In FIG. 12 , illustration of a light control element including an optical film of a polarizing plate, a diffusion plate, and the like, an alignment film, and the like is omitted.

The liquid crystal display device 950 includes: a black matrix substrate 650 ; an array substrate 901 ; a liquid crystal layer LC arranged between the black matrix substrate 650 and the array substrate 901 ; a cover glass 904 ; and a backlight unit 903 . A touch panel can also be added between the cover glass 904 and the black matrix substrate 650 .

In FIG. 12 , the backlight unit 903 is a direct-lit backlight unit (hereinafter referred to as BLU) in which LED chips with a size of 5 μm to 100 μm are arranged in a matrix, and is called Mini LED. In the Mini LED method, a local dimming method such as locally lowering the light emission of the BLU in the display area to dim light or high-intensity light in accordance with the image displayed on the liquid crystal display device 950 is generally adopted. In addition, the size of the LED chip used in the Mini LED can also be other than the above-mentioned size.

In a conventional liquid crystal display device, only a liquid crystal layer is used as a display function layer, and light emission (brightness) from a display surface is controlled to display an image. In a conventional liquid crystal display device, the backlight system is kept on during image display, so light leakage from the liquid crystal layer tends to occur. Therefore, even in the state of black display, it will not become completely black. display, has the disadvantage of reduced contrast. In the Mini LED method, depending on the content of the displayed image, for example, by partially turning off the light in the display area, a complete black display can be obtained.

The luminous efficiency of LED containing Mini LED is much better than that of organic EL. Mini LED with local dimming technology for completely black display has the possibility of surpassing organic EL.

In addition, as the chip size of LEDs used in Mini LEDs, the size of 5 μm to 100 μm can be mentioned, but in large-scale display devices such as electronic signage, LED chips larger than 100 μm can also be used.

Furthermore, instead of using LED chips that emit red light, green light, and blue light, a BLU of Mini LED using a white light-emitting LED chip can be used in combination with a color filter. In this case, it is easy to control the BLU including the wiring of the BLU.

In addition, in a liquid crystal display device to which a field sequential technology is applied to emit red light, green light, and blue light in time-division sequentially, the color filter can be omitted.

The black matrix substrate of the above embodiment or a display device including the black matrix substrate can be used in various applications. Examples of electronic equipment to which the display device of the above-mentioned embodiment is applicable include mobile phones, mobile game machines, mobile information terminals, personal computers, electronic books, video cameras, digital cameras, head-mounted displays, navigation systems, and audio reproduction devices. (Car stereos, digital audio players, etc.), copiers, facsimile machines, printers, multi-function printers, vending machines, automatic teller machines (ATMs), personal authentication equipment, optical communication equipment, IC cards, etc. sub-device etc. The various embodiments described above can be freely combined and used. It is preferable that an electronic device equipped with the black matrix substrate according to the embodiment of the present invention is further equipped with an antenna for receiving and feeding power by communication or non-contact.

Although the preferred embodiments of the present invention have been described as above, it should be understood that these embodiments are illustrative embodiments of the present invention and should not be considered as limited embodiments. Additions, omissions, substitutions, and other changes can be made without departing from the scope of the present invention. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope claimed.

Claims (9)

A black matrix substrate, comprising: a transparent substrate; a semi-transmissive film formed on the aforementioned transparent substrate; a first black matrix layer formed on the aforementioned semi-transmissive film in the thickness direction of the aforementioned semi-transmissive film on the transmissive film, and has a plurality of first openings; a transparent resin layer is formed on the aforementioned semi-transmissive film in a manner covering the aforementioned first black matrix layer; and a second black matrix layer is formed on the aforementioned transparent resin layer, And it is provided with a plurality of second openings; in a plan view viewed from the surface opposite to the surface of the aforementioned transparent substrate on which the aforementioned semi-transmissive film is formed, the aforementioned semi-transmissive film is to cover the plurality of aforementioned first openings and the aforementioned The first black matrix layers are overlapped in such a way that in a plan view, the positions of the plurality of the second openings correspond to the positions of the plurality of the first openings. The black matrix substrate of claim 1, wherein the semi-transmissive film contains carbon as a pigment, and the transmittance of the semi-transmissive film to visible light is in the range of 98% to 60%. The black matrix substrate according to claim 1, wherein the semi-transmissive film is a dispersion comprising carbon, optically isotropic microparticles, and a resin in which the carbon and the microparticles are dispersed. The black matrix substrate as claimed in claim 3, wherein the aforementioned microparticles are silicon dioxide microparticles. Such as the black matrix substrate of claim 3 or 4, wherein the total solid content containing the aforementioned resin, the aforementioned carbon, and the aforementioned fine particles is set to 100% by mass, the amount of the aforementioned carbon is in the range of 0.5% by mass to 15% by mass, and the aforementioned The amount of fine particles is in the range of 1% by mass to 30% by mass. The black matrix substrate according to claim 1, wherein the line width of the second black matrix layer is smaller than the line width of the first black matrix layer. The black matrix substrate according to claim 1, wherein the second black matrix layer is light-transmissive to the near-infrared region. The black matrix substrate according to claim 1, wherein each of the plurality of first openings of the first black matrix layer has a colored layer. A display device comprising: the black matrix substrate according to any one of claims 1 to 8; a display function layer; and an array substrate with a plurality of active elements.

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