KR20200073805A - Display device - Google Patents

Abstract

Provided is a display device capable of increasing the aperture ratio of a pixel. According to an embodiment of the present invention, the display device comprises: a substrate having a first sub-pixel and a second sub-pixel; a bank provided on the substrate and having an undercut structure in which the width of a lower surface thereof is smaller than the width of an upper surface thereof; a first electrode provided on the substrate and the bank and disconnected between the first sub-pixel and the second sub-pixel by an undercut structure of the bank; and a light emitting layer provided on the first electrode; and a second electrode provided on the light emitting layer.

Description

Display device {DISPLAY DEVICE}

The present invention relates to a display device for displaying an image.

As the information society develops, the demand for display devices for displaying images is increasing in various forms. Accordingly, in recent years, liquid crystal display (LCD, Liquid Crystal Display), plasma display (PDP, Plasma Display Panel), quantum dot light emitting display (QLED: Quantum dot Light Emitting Display), organic light emitting display (OLED, Organic Light Emitting Display) are used.

Among the display devices, the organic light emitting display device is a self-emission type, and has an excellent viewing angle, contrast ratio, and the like, compared to a liquid crystal display device (LCD), and requires a separate backlight. . In addition, the organic light emitting display device has advantages such as DC low voltage driving, fast response speed, and low manufacturing cost.

Recently, a head mounted display including such an organic light emitting display device has been developed. A head mounted display (HMD) is a virtual reality (VR) or augmented reality (Augmented Reality) glasses type monitor device that is worn in the form of glasses or a helmet and focus is formed at a distance close to the user's eyes. However, in the case of an ultra-high resolution head-mounted display, the aperture ratio is small due to the dense pixel spacing, and thus, there is a problem that light efficiency is lowered.

An object of the present invention is to provide a display device capable of increasing the aperture ratio of a pixel.

A display device according to an exemplary embodiment of the present invention includes a substrate having a first sub-pixel and a second sub-pixel, a bank provided on the substrate, and a bank having an undercut structure in which the width of the lower surface is smaller than the width of the upper surface, on the substrate and the bank. It includes a first electrode that is provided and is cut off between the first sub-pixel and the second sub-pixel by the uncut structure of the bank, the light-emitting layer provided on the first electrode, and the second electrode provided on the light-emitting layer.

According to the present invention, the first electrode can be cut between the sub-pixels using a bank having an undercut structure. Accordingly, the present invention can form the first electrode for each sub-pixel without a separate pattern process.

In addition, the present invention can form an undercut structure having a different separation distance on each of the first and second sides of the bank. In the present invention, in the undercut structure having a relatively small separation distance, the first electrode can be connected without being disconnected. In the present invention, since not only the area where the bank is not formed but also the area where the bank is formed can be an emission area, the aperture ratio of each of the sub-pixels can be secured to the maximum. Accordingly, the present invention can greatly improve light efficiency.

In addition, the present invention can prevent the light-emitting layer from being cut off or the seam from being formed due to the undercut structure of the bank by forming a short circuit preventing layer. Furthermore, the present invention can prevent the second electrode and the first electrode from being shorted by allowing the light emitting layer to completely cover the first electrode.

In addition to the effects of the present invention mentioned above, other features and advantages of the present invention are described below, or will be clearly understood by those skilled in the art from the description and description.

1 is a perspective view showing a display device according to an exemplary embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a first embodiment of II of FIG. 1.
3 is an enlarged view showing an example of region A of FIG. 2.
4 is a cross-sectional view showing a second embodiment of II of FIG. 1.
5 is an enlarged view showing an example of area B of FIG. 4.
6 is a cross-sectional view showing a third embodiment of II of FIG. 1.
7 is an enlarged view showing an example of region C of FIG. 6.
8 is a flowchart illustrating a method of manufacturing a display device according to an exemplary embodiment of the present invention.
9A to 9K are cross-sectional views illustrating a method of manufacturing a display device according to an exemplary embodiment of the present invention.
10A to 10C relate to a display device according to another exemplary embodiment of the present invention, which relates to a head mounted display (HMD) device.

Advantages and features of the present invention, and methods for achieving them will be clarified with reference to examples described below in detail together with the accompanying drawings. However, the present invention is not limited to the examples disclosed below, but will be implemented in various different forms, only the examples allow the disclosure of the present invention to be complete, and to those skilled in the art to which the present invention pertains. It is provided to fully inform the scope of the invention, and the invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining examples of the present invention are exemplary, and the present invention is not limited to the illustrated matters. The same reference numerals refer to the same components throughout the specification. In addition, in the description of the present invention, when it is determined that detailed descriptions of related known technologies may unnecessarily obscure the subject matter of the present invention, detailed descriptions thereof will be omitted. When'include','have','consist of' and the like mentioned in the present invention are used, other parts may be added unless'~man' is used. When a component is expressed as a singular number, the plural number is included unless otherwise specified.

In interpreting the components, it is interpreted as including the error range even if there is no explicit description.

In the case of the description of the positional relationship, for example, when the positional relationship of two parts is described as'~top','~upper','~bottom','~side', etc.,'right' Alternatively, one or more other parts may be located between the two parts unless'direct' is used.

The first, second, etc. are used to describe various components, but these components are not limited by these terms. These terms are only used to distinguish one component from another component. Accordingly, the first component mentioned below may be the second component within the technical spirit of the present invention.

In describing the components of the present invention, terms such as first and second may be used. These terms are only for distinguishing the component from other components, and the essence, order, order, or number of the component is not limited by the term. When a component is described as being "connected", "coupled" or "connected" to another component, the component may be directly connected to or connected to the other component, but different components between each component It will be understood that the "intervenes" may be, or each component may be "connected", "coupled" or "connected" through other components.

Each of the features of the various examples of the present invention can be partially or wholly combined with or combined with each other, technically various interlocking and driving are possible, and each of the examples can be independently implemented with respect to each other, or can be implemented together in an associative relationship. .

Hereinafter, an example of a display device according to the present invention will be described in detail with reference to the accompanying drawings. In adding reference numerals to the components of each drawing, the same components may have the same reference numerals as possible even though they are displayed on different drawings.

The first Example

1 is a perspective view showing a display device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing a first embodiment of II of FIG. 1, and FIG. 3 is an enlarged view showing an example of area A of FIG. 2 .

1 to 3, the display device 100 according to an exemplary embodiment of the present invention includes a substrate 110, a driving thin film transistor (TFT), an interlayer insulating film 112, a first electrode 120, and a light emitting layer ( 130, a second electrode 140, an encapsulation film 150, a color filter 160, a bank 220, and a short circuit protection layer 230.

The substrate 110 may be a plastic film, a glass substrate, or a silicon wafer substrate formed using a semiconductor process. The substrate 110 may be made of a transparent material or an opaque material.

A first sub-pixel P1, a second sub-pixel P2, and a third sub-pixel P3 may be provided on the substrate 110. The first sub-pixel P1 emits red light, the second sub-pixel P2 emits green light, and the third sub-pixel P3 may be provided to emit blue light, but is not limited thereto. It is not. A fourth sub-pixel emitting light of white (W) may be further provided on the substrate 110. In addition, the arrangement order of each sub-pixel P1, P2, P3 may be variously changed.

The display device 100 according to an exemplary embodiment of the present invention is made of a so-called top emisison method in which emitted light is emitted upward, and thus, the material of the substrate 110 is not only transparent but also opaque. Materials can be used.

On the substrate 110, circuit elements including various signal wires, thin film transistors, and capacitors are formed for each of the pixels P1, P2, and P3. The signal wires may include a gate wire, a data wire, a power wire, and a reference wire, and the thin film transistor may include a switching thin film transistor, a driving thin film transistor (TFT), and a sensing thin film transistor.

The switching thin film transistor is switched according to a gate signal supplied to the gate wiring and serves to supply a data voltage supplied from the data wiring to the driving thin film transistor.

The driving thin film transistor TFT is switched according to the data voltage supplied from the switching thin film transistor to generate a data current from the power supplied from the power line and supply it to the first electrode 120.

The sensing thin film transistor serves to sense a threshold voltage deviation of the driving thin film transistor that causes a deterioration in image quality, and the current of the driving thin film transistor in response to a sensing control signal supplied from the gate wiring or a separate sensing wiring. Is supplied to the reference wiring.

The capacitor serves to maintain the data voltage supplied to the driving thin film transistor TFT for one frame, and is connected to the gate terminal and the source terminal of the driving thin film transistor TFT, respectively.

The interlayer insulating film 112 is formed on a circuit element including a driving thin film transistor (TFT). The interlayer insulating film 112 may be formed of an inorganic film, for example, a silicon oxide film (SiOx), a silicon nitride film (SiNx), or multiple films thereof, but is not limited thereto. The interlayer insulating film 112 is made of an organic film, for example, an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin. It may be formed. Alternatively, the interlayer insulating film 112 may be formed of a multi-layer film composed of at least one inorganic film and at least one organic film.

The bank 220 is patterned for each of the sub-pixels P1, P2, and P3 on the interlayer insulating layer 112. One bank 220 is formed in the edge region of the first sub-pixel P1, another bank 220 is formed in the edge region of the second sub-pixel P2, and the third sub-pixel P3 Another bank 220 is formed in the edge region of.

The bank 220 includes an upper layer 221 and a lower layer 222.

The lower layer 222 is provided on the interlayer insulating layer 112 to have a first width W1. The lower layer 222 may include a first layer 211 and a second layer 212. The first layer 211 is provided on the interlayer insulating layer 112 to have a first width W1. The second layer 212 is provided on a portion of the first layer 211 to have a third width W3. At this time, the third width W3 is smaller than the first width W1. That is, the second layer 212 is formed to have a width smaller than that of the first layer 211, and a part of the first layer 211 may be exposed.

The second layer 212 is biased to one side on the first layer 211. More specifically, the upper layer 221 includes a first end formed on the first side 220a and a second end formed on the second side 220b. The second layer 212 forms a third end formed on the first side 220a and a fourth end formed on the second side 220b. The distance between the fourth end of the second layer 212 and the second end of the upper layer 221 is formed smaller than the distance between the third end of the second layer 212 and the first end of the upper layer 221. That is, the second layer 212 may be formed closer to the second side 220b than the first side 220a. Here, the first side 220a may indicate a side facing the corresponding sub-pixel on which the bank 220 is disposed, and the second side 220b may indicate a side facing the sub-pixel adjacent to the corresponding sub-pixel.

Accordingly, the lower layer 222 of the bank 220 may be formed thicker on the second side 220b than on the first side 220a. Specifically, the lower layer 222 of the bank 220 has a thickness T1 of the first layer 211 on the first side 220a, and a thickness of the first layer 211 on the second side 220b ( T1) and the thickness T2 of the second layer 212 may be combined.

The lower layer 222 may be formed of an inorganic film, for example, silicon nitride, aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride, silicon oxide, aluminum oxide or titanium oxide.

The upper layer 221 is provided on the lower layer 222 and has a second width W2 greater than the first width W1. The upper layer 221 may have a convex shape toward the encapsulation layer 150 as shown in FIGS. 2 and 3, but is not limited thereto.

Unlike the lower layer 222, the upper layer 221 is an organic film, for example, an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin. (polyimide resin).

The bank 220 may have undercut structures UC1 and UC2 because the upper layer 221 has a larger width than the lower layer 222. More specifically, the bank 220 has a first undercut structure UC1 on the first side 220a, as shown in FIGS. 2 and 3, and the second side 220b facing the first side 220a. ) May have a second undercut structure (UC2).

The first undercut structure UC1 of the bank 220 may be formed by forming the upper layer 221 larger than the lower layer 222 on the first side 220a. In the first undercut structure UC1 of the bank 220, a space may be formed between the interlayer insulating layer 112 and the lower surface 221b of the upper layer 221 in a region where the lower layer 222 is not formed.

The first undercut structure UC1 may have a first separation distance S1 between the interlayer insulating layer 112 and the lower surface 221b of the upper layer 221. In this case, the first separation distance S1 may correspond to the thickness T1 of the first layer 211 of the lower layer 222. This is because the lower layer 222 has only the first layer 211 formed on the first side 220a.

The second undercut structure UC2 of the bank 220 may be formed by forming the upper layer 221 larger than the lower layer 222 on the second side 220b. In the second undercut structure UC2 of the bank 220, a space may be formed between the interlayer insulating layer 112 and the lower surface 221b of the upper layer 221 in a region where the lower layer 222 is not formed.

The second undercut structure UC2 may have a second separation distance S2 between the interlayer insulating layer 112 and the lower surface 221b of the upper layer 221. At this time, the second separation distance S2 may correspond to a thickness of the thickness T1 of the first layer 211 of the lower layer 222 and the thickness T2 of the second layer 212. This is because the lower layer 222 has a first layer 211 and a second layer 212 formed on the second side 220b, unlike the first side 220a.

That is, the second undercut structure UC2 has a greater separation distance between the interlayer insulating film 112 and the lower surface 221b of the upper layer 221 than the first undercut structure UC1, and the interlayer insulating film 112 and the upper layer 221 ), a large space may be formed between the lower surfaces 221b.

The first electrode 120 is patterned for each of the sub-pixels P1, P2, and P3 on the interlayer insulating layer 112 and the bank 220. One first electrode 120 is formed in the first sub-pixel P1, the other first electrode 120 is formed in the second sub-pixel P2, and the third sub-pixel P3 is further formed. Another first electrode 120 is formed.

The first electrode 120 is connected to a source terminal or a drain terminal of the driving thin film transistor TFT through a contact hole CH passing through the interlayer insulating layer 112, and a voltage for emitting light is applied.

The first electrode 120 according to an embodiment of the present invention may also be formed on the bank 220. The first electrode 120 may be cut between the sub-pixels P1, P2, and P3 by the undercut structure of the bank 220, in particular, the second undercut structure UC2.

More specifically, the first electrode 120 may be formed by depositing the entire surface on the substrate 110 on which the bank 220 is formed. The first electrode 120a may be formed on the exposed interlayer insulating layer 112 without the bank 220 being formed. In addition, the first electrode 120b may be formed on the bank 220. In this case, the first electrode 120b formed on the bank 220 may be connected to the first electrode 120a formed on the interlayer insulating layer 112 on the first side 220a. The first undercut structure UC1 of the bank 220 has a relatively small first separation distance S1 between the interlayer insulating layer 112 and the lower surface 221b of the upper layer 221. Since the first electrode 120b formed on the bank 220 has a small first separation distance S1 in which the first undercut structure UC1 is small, the first electrode 120a formed on the interlayer insulating film 112 is not disconnected. ).

Accordingly, each of the sub-pixels P1, P2, and P3 may be an emission area EA, not only the region NBA in which the bank 220 is not formed, but also the region BA in which the bank 220 is formed. .

The first electrode 120 may define the emission area EA in each of the sub-pixels P1, P2, and P3. That is, a region in which the first electrode 120 is formed in each sub-pixel P1, P2, and P3 may be a light-emitting region EA.

The display device 100 according to an exemplary embodiment of the present invention can secure the aperture ratio of each of the sub-pixels P1, P2, and P3 to the maximum, and thereby, greatly improve the light efficiency.

Meanwhile, the first electrode 120b formed on the bank 220 may be cut off from the first electrode 120a formed on the interlayer insulating layer 112 on the second side 220b. The second undercut structure UC2 of the bank 220 has a relatively large second separation distance S2 between the interlayer insulating layer 112 and the lower surface 221b of the upper layer 221. The first electrode 120b formed on the bank 220 is connected to the first electrode 120a formed on the interlayer insulating layer 112 because the second undercut structure UC2 has a large second separation distance S2. It can't be done and can be cut off. Accordingly, the first electrodes 120 formed in each of the adjacent sub-pixels P1, P2, and P3 may not be electrically connected to each other.

In the display device 100 according to an exemplary embodiment of the present invention, the first electrode 120 may be formed for each sub-pixel P1, P2, P3 without a separate pattern process.

The first electrode 120 may be made of a transparent metal material, a semi-transmissive metal material, or a high reflectance metal material. When the display device 100 is made of an upper emission method, the first electrode 120 is a stacked structure of aluminum and titanium (Ti/Al/Ti), a stacked structure of aluminum and ITO (ITO/Al/ITO), and an Ag alloy. And, it may be formed of a metal material having a high reflectance, such as a laminated structure of ITO and Ag alloy (ITO / Ag alloy / ITO). The Ag alloy may be an alloy such as silver (Ag), palladium (Pd), and copper (Cu). When the display device 100 is made of a lower emission method, the first electrode 120 is a transparent metallic material (TCO, transparent conductive material) such as ITO, IZO, or magnesium (Mg), silver ( Ag), or a semi-transmissive conductive material, such as an alloy of magnesium (Mg) and silver (Ag). The first electrode 120 may be an anode electrode.

The short circuit prevention layer 230 is formed on the second side 220b of the bank 220. More specifically, the short circuit prevention layer 230 is formed between the interlayer insulating layer 112 and the lower surface 221b of the upper layer 221 on the second side 220b of the bank 220.

The bank 220 has a second undercut structure UC2 at the second side 220b. When the light emitting layer 130 is deposited on the first electrode 120 after the first electrode 120 is deposited, the light emitting layer 130 may be cut off by the second undercut structure UC2 or a seam may occur. have. At this time, the light emitting layer 130 may not completely cover the first electrode 120 and may expose a part.

Then, when the second electrode 140 is deposited on the light emitting layer 130, the second electrode 140 may be deposited on the light emitting layer 130 as well as the exposed first electrode 120. In this case, the second electrode 140 and the first electrode 120 are short-circuited, resulting in poor contact.

In order to prevent this, the display device 100 according to an exemplary embodiment of the present invention includes a short circuit prevention layer between the interlayer insulating layer 112 and the lower surface 221b of the upper layer 221 on the second side 220b of the bank 220. 230 may be further formed. The short circuit prevention layer 230 is formed to fill a space between the interlayer insulating layer 112 formed by the second undercut structure UC2 and the lower surface 221b of the upper layer 221.

Accordingly, the short circuit preventing layer 230 may prevent the light emitting layer 130 from being deposited on the second undercut structure UC2, thereby preventing the light emitting layer 130 from being disconnected or a seam. Furthermore, the short circuit prevention layer 230 may prevent the second electrode 140 and the first electrode 120 from being shorted by allowing the light emitting layer 130 to completely cover the first electrode 120.

The short circuit layer 230 is an organic film, for example, acrylic resin (acryl resin), epoxy resin (epoxy resin), phenolic resin (phenolic resin), polyamide resin (polyamide resin), polyimide resin (polyimide resin), etc. It can be formed as.

The emission layer 130 is formed on the first electrode 120. The light emitting layer 130 may include a hole transporting layer, a light emitting layer, and an electron transporting layer. In this case, when voltage is applied to the first electrode 120 and the second electrode 140, holes and electrons move to the light emitting layer through the hole transport layer and the electron transport layer, respectively, and the light emitting layers combine to emit light.

The emission layer 130 may be a white emission layer that emits white light. In this case, the light emitting layer 130 may be a common layer commonly formed in the sub-pixels P1, P2, and P3.

When the light emitting layer 130 is a white light emitting layer, it may be formed in a tandem structure of two or more stacks. Each of the stacks may include a hole transporting layer, at least one light emitting layer, and an electron transporting layer.

Also, a charge generating layer may be formed between the stacks. The charge generation layer may include an n-type charge generation layer positioned adjacent to the lower stack and a p-type charge generation layer formed adjacent to the upper stack and formed on the n-type charge generation layer. The n-type charge generation layer injects electrons into the lower stack, and the p-type charge generation layer injects holes into the upper stack. The n-type charge generation layer may be formed of an alkali metal such as Li, Na, K, or Cs, or an organic layer doped with an alkaline earth metal such as Mg, Sr, Ba, or Ra. The p-type charge generation layer may be formed by doping a dopant in an organic material having hole transport capability.

Meanwhile, in FIG. 2, the light emitting layer 130 is illustrated as a common layer commonly formed in a plurality of sub-pixels P1, P2, and P3, but is not limited thereto. The emission layer 130 may be formed of a red emission layer that emits red light, a green emission layer that emits green light, and a blue emission layer that emits blue light. In this case, the light emitting layer 130 may be patterned for each sub-pixel P1, P2, P3. For example, a red emission layer may be formed on the first sub-pixel P1, a green emission layer may be formed on the second sub-pixel P2, and a blue emission layer may be formed on the third sub-pixel P3.

The second electrode 140 is formed on the light emitting layer 130. The second electrode 140 may be a common layer commonly formed in the sub-pixels P1, P2, and P3.

The second electrode 140 may be made of a transparent metal material, a semi-transmissive metal material, or a high reflectance metal material. When the display device 100 is made of an upper emission method, the second electrode 140 is a transparent metallic material (TCO, transparent conductive material) such as ITO, IZO, or magnesium (Mg), silver ( Ag), or a semi-transmissive conductive material, such as an alloy of magnesium (Mg) and silver (Ag). When the display device 100 is made of a lower emission method, the second electrode 140 is a stacked structure of aluminum and titanium (Ti/Al/Ti), a stacked structure of aluminum and ITO (ITO/Al/ITO), and an Ag alloy. , And Ag alloy and ITO stacked structure (ITO / Ag alloy / ITO) may be formed of a high reflectivity metal material. The Ag alloy may be an alloy such as silver (Ag), palladium (Pd), and copper (Cu). The second electrode 140 may be a cathode electrode.

The encapsulation film 150 may be formed to cover the second electrode 140. The encapsulation film 150 serves to prevent oxygen or moisture from penetrating the light emitting layer 130 and the second electrode 140. To this end, the encapsulation film 150 may include at least one inorganic film and at least one organic film.

Specifically, the encapsulation film 150 may include a first inorganic film 151 and an organic film 152. In one embodiment, the encapsulation film 150 may further include a second inorganic film 153.

The first inorganic layer 151 is formed to cover the second electrode 140. The organic layer 152 is formed on the first inorganic layer 151 and prevents particles from penetrating the first inorganic layer 151 and entering the emission layer 130 and the second electrode 140. It is preferably formed to a sufficient thickness. The second inorganic layer 153 is formed to cover the organic layer 152. The second inorganic film 153 may be omitted.

Each of the first and second inorganic films 151 and 153 may be formed of silicon nitride, aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride, silicon oxide, aluminum oxide, or titanium oxide. The first and second inorganic layers 151 and 153 may be deposited by a chemical vapor deposition (CVD) technique or an atomic layer deposition (ALD) technique, but are not limited thereto.

The organic film 152 may be formed of an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin. The organic layer 152 may be formed by vapor deposition, printing, or slit coating using an organic material, but is not limited thereto, and the organic layer 152 is inkjet (ink- jet) process.

The color filter 160 is formed on the encapsulation film 150. The color filter 160 includes a first color filter CF1, a second color filter CF2, and a third color filter CF3 arranged to correspond to each of the sub pixels P1, P2, and P3. The first color filter CF1 may be a red color filter that transmits red light, the second color filter CF2 may be a green color filter that transmits green light, and the third color filter CF3 may be blue light. It may be a blue color filter that transmits.

2nd Example

4 is a cross-sectional view showing a second embodiment of I-I of FIG. 1, and FIG. 5 is an enlarged view showing an example of area B of FIG. 4.

4 and 5, the display device 100 according to another exemplary embodiment of the present invention includes a substrate 110, a driving thin film transistor (TFT), an interlayer insulating film 112, a first electrode 120, and a light emitting layer ( 130, a second electrode 140, an encapsulation film 150, a color filter 160, a bank 220, and a short circuit protection layer 230.

In the display device 100 according to another exemplary embodiment of the present invention, components other than the short circuit preventing layer 230 are substantially different from those of the display device 100 according to an exemplary embodiment of the present invention illustrated in FIGS. 2 and 3. same.

Hereinafter, the substrate 110, the driving substrate 110, the driving thin film transistor (TFT), the interlayer insulating film 112, the first electrode 120, the light emitting layer 130 of the display device 100 according to another embodiment of the present invention ), a detailed description of the second electrode 140, the encapsulation film 150, the color filter 160, and the bank 220 will be omitted.

The short circuit prevention layer 230 is formed on the second side 220b of the bank 220. More specifically, the short circuit prevention layer 230 is formed between the interlayer insulating layer 112 and the lower surface 221b of the upper layer 221 on the second side 220b of the bank 220, and the end of the first electrode 120 It is formed to cover.

The bank 220 has a second undercut structure UC2 at the second side 220b. When the light emitting layer 130 is deposited on the first electrode 120 after the first electrode 120 is deposited, the light emitting layer 130 may be cut off by the second undercut structure UC2 or a seam may occur. have. At this time, the light emitting layer 130 may not completely cover the first electrode 120 and may expose a part.

Then, when the second electrode 140 is deposited on the light emitting layer 130, the second electrode 140 may be deposited on the light emitting layer 130 as well as the exposed first electrode 120. In this case, the second electrode 140 and the first electrode 120 are short-circuited, resulting in poor contact.

In order to prevent this, the display device 100 according to another exemplary embodiment of the present invention includes a short circuit prevention layer between the interlayer insulating layer 112 and the lower surface 221b of the upper layer 221 on the second side 220b of the bank 220. 230 may be further formed. The short circuit prevention layer 230 is formed to fill a space between the interlayer insulating layer 112 formed by the second undercut structure UC2 and the lower surface 221b of the upper layer 221. In addition, the short circuit preventing layer 230 is formed to cover the end of the first electrode 120.

Accordingly, the short circuit preventing layer 230 may prevent the light emitting layer 130 from being deposited on the second undercut structure UC2, thereby preventing the light emitting layer 130 from being disconnected or a seam. Furthermore, the short circuit prevention layer 230 may prevent the second electrode 140 and the first electrode 120 from being shorted by allowing the light emitting layer 130 to completely cover the first electrode 120.

On the other hand, unlike the display device 100 according to an exemplary embodiment of the present invention, the display device 100 according to another exemplary embodiment of the present invention includes a short circuit prevention layer 230 in each of the sub-pixels P1, P2, and P3. The emission region EA may be defined. That is, in each sub-pixel P1, P2, and P3, the short-circuit preventing layer 230 is not formed and the area where the first electrode 120 is exposed may be the light-emitting area EA. On the other hand, a region other than the emission region EA may be a non-emission region.

In the display device 100 according to another embodiment of the present invention, the light emitting area EA is somewhat reduced compared to the display device 100 according to an embodiment of the present invention, but the first electrode ( By covering the end of 120), it is possible to prevent a problem that a current is concentrated at the end of the first electrode 120 and the light emission efficiency is lowered.

Third Example

6 is a cross-sectional view showing a third embodiment of I-I of FIG. 1, and FIG. 7 is an enlarged view showing an example of region C of FIG. 6.

6 and 7, the substrate 110, the driving thin film transistor (TFT), the interlayer insulating film 112, the first electrode 120, the light emitting layer 130, the second according to another embodiment of the present invention It includes an electrode 140, an encapsulation film 150, a color filter 160, a bank 220, and a short circuit preventing layer 230.

The display device 100 according to another embodiment of the present invention has substantially the same configuration as the display device 100 according to an embodiment of the present invention illustrated in FIGS. 2 and 3 except for the bank 220 Do.

Hereinafter, the substrate 110, the substrate 110, the driving thin film transistor (TFT), the interlayer insulating film 112, the first electrode 120, the light emitting layer 130 of the display device 100 according to another embodiment of the present invention ), the second electrode 140, the sealing film 150, the color filter 160 and the detailed description of the short circuit layer 230 will be omitted.

The bank 220 is patterned for each of the sub-pixels P1, P2, and P3 on the interlayer insulating layer 112. One bank 220 is formed in the edge region of the first sub-pixel P1, another bank 220 is formed in the edge region of the second sub-pixel P2, and the third sub-pixel P3 Another bank 220 is formed in the edge region of.

The bank 220 includes an upper layer 221 and a lower layer 222.

The lower layer 222 is provided on the interlayer insulating layer 112 to have a third width W3. The lower layer 222 may be formed of the second layer 212. The second layer 212 is formed on the substrate 110. The second layer 212 may be formed to be biased toward the second side 220b rather than the first side 220a. The first side 220a may indicate a side facing the corresponding sub-pixel in which the bank 220 is disposed, and the second side 220b may indicate a side facing the sub-pixel adjacent to the corresponding sub-pixel.

Accordingly, the lower layer 222 of the bank 220 may have a predetermined thickness only on the second side 220b. Specifically, the lower layer 222 of the bank 220 may have a thickness T3 of the second layer 212 at the second side 220b.

The lower layer 222 may be formed of an inorganic film, for example, silicon nitride, aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride, silicon oxide, aluminum oxide or titanium oxide.

The upper layer 221 is provided on the lower layer 222 and has a second width W2 greater than the third width W3. The upper layer 221 may have a convex shape toward the encapsulation layer 150 as shown in FIGS. 6 and 7, but is not limited thereto.

Unlike the lower layer 222, the upper layer 221 is an organic film, for example, an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin. (polyimide resin).

The bank 220 may have undercut structures UC1 and UC2 because the upper layer 221 has a larger width than the lower layer 222. More specifically, the bank 220 may have a second undercut structure UC2 on the second side 220b facing the first side 220a, as shown in FIGS. 6 and 7.

In the bank 220, the upper layer 221 is formed on the interlayer insulating layer 112 on the first side 220a. That is, the bank 220 does not have a space formed between the interlayer insulating layer 112 and the lower surface 221b of the upper layer 221 on the first side 220a. This is because the lower layer 222 is not formed on the first side 220a.

The second undercut structure UC2 of the bank 220 may be formed by forming the upper layer 221 larger than the lower layer 222 on the second side 220b. In the second undercut structure UC2 of the bank 220, a space may be formed between the interlayer insulating layer 112 and the lower surface 221b of the upper layer 221 in a region where the lower layer 222 is not formed.

The second undercut structure UC2 may have a second separation distance S2 between the interlayer insulating layer 112 and the lower surface 221b of the upper layer 221. At this time, the second separation distance S2 may correspond to the thickness T3 of the second layer 212 of the lower layer 222. This is because the second layer 212 is formed on the lower layer 222 unlike the first side 220a on the second side 220b.

8 is a flowchart illustrating a method of manufacturing a display device according to an exemplary embodiment of the present invention, and FIGS. 9A to 9K are cross-sectional views showing a method of manufacturing the display device according to an exemplary embodiment of the present invention.

First, a circuit element and an interlayer insulating layer 112 are formed on the substrate 110 (S801).

More specifically, as shown in FIG. 9A, a driving thin film transistor (TFT) is formed on the substrate 110.

Then, an interlayer insulating film 112 is formed on the driving thin film transistor TFT. The interlayer insulating film 112 may be formed of an inorganic film, for example, a silicon oxide film (SiOx), a silicon nitride film (SiNx), or multiple films thereof, but is not limited thereto. The interlayer insulating film 112 is made of an organic film, for example, an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin. It may be formed. Alternatively, the interlayer insulating film 112 may be formed of a multi-layer film composed of at least one inorganic film and at least one organic film.

Next, the bank 220 is formed (S802).

More specifically, the first layer 211 is formed on the interlayer insulating layer 112 as shown in FIG. 9B. The first layer 211 may be formed of an inorganic film, for example, silicon nitride, aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride, silicon oxide, aluminum oxide or titanium oxide.

Then, a second layer 212 is patterned on the first layer 211 as shown in FIG. 9C. The second layer 212 is patterned on the first layer 211 so that a portion of the first layer 211 is exposed. The second layer 212 may be formed of an inorganic film, for example, silicon nitride, aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride, silicon oxide, aluminum oxide or titanium oxide.

The second layer 212 may be made of the same material as the first layer 211, but is not limited thereto. Meanwhile, the first layer 211 and the second layer 212 may be made of a different material from the interlayer insulating layer 112.

Then, the upper layer 221 is patterned on the first layer 211 and the second layer 212 as shown in FIG. 9D. The upper layer 221 is patterned for each sub-pixel P1, P2, P3. One upper layer 221 is formed in the edge region of the first sub-pixel P1, another upper layer 221 is formed in the edge region of the second sub-pixel P2, and the third sub-pixel P3 is formed. Another upper layer 221 is formed in the edge region of.

Unlike the first layer 211 and the second layer 212, the upper layer 221 is an organic film, for example, an acrylic resin, an epoxy resin, a phenolic resin, or a polyamide resin. It may be formed of (polyamide resin), polyimide resin, or the like.

Then, an etching process is performed as shown in FIG. 9E to form a bank 220 having an undercut structure. In this case, the etching process may be a wet etch process, and the first layer 211 and the second layer 212 of the lower layer 222 may be etched, but the upper layer 221 may not be etched. Can be used. In addition, the etching solution should not be able to etch the interlayer insulating film 112. Accordingly, the upper layer 221 and the interlayer insulating layer 112 are not etched, and only the exposed first layer 211 and the second layer 212 are etched, and the first undercut structure UC1 and the second undercut structure UC2 are etched. Bank 220 with) may be formed.

Next, the first electrode 120 is formed (S803).

More specifically, as illustrated in FIG. 9F, the first electrode 120 is formed on the interlayer insulating layer 112 and the bank 220. The first electrode 120 is deposited on the substrate 110 on which the bank 220 is formed. The first electrode 120a is not formed on the bank 220 but is formed on the exposed interlayer insulating layer 112. In addition, the first electrode 120b is also formed on the bank 220. At this time, the first electrode 120b formed on the bank 220 is connected to the first electrode 120a formed on the interlayer insulating layer 112 on the first side.

Meanwhile, the first electrode 120b formed on the bank 220 and the first electrode 120a formed on the interlayer insulating layer 112 by the second undercut structure UC2 at the second side facing the first side Cut off. Accordingly, the first electrodes 120 formed in each of the adjacent sub-pixels P1, P2, and P3 are not electrically connected to each other.

The first electrode 120 is connected to the source terminal or the drain terminal of the driving thin film transistor TFT through the contact hole CH.

The first electrode 120 may be made of a transparent metal material, a semi-transmissive metal material, or a high reflectance metal material. When the display device 100 is made of an upper emission method, the first electrode 120 is a stacked structure of aluminum and titanium (Ti/Al/Ti), a stacked structure of aluminum and ITO (ITO/Al/ITO), and an Ag alloy. And, it may be formed of a metal material having a high reflectance, such as a laminated structure of ITO and Ag alloy (ITO / Ag alloy / ITO). The Ag alloy may be an alloy such as silver (Ag), palladium (Pd), and copper (Cu). When the display device 100 is made of a lower emission method, the first electrode 120 is a transparent metallic material (TCO, transparent conductive material) such as ITO, IZO, or magnesium (Mg), silver ( Ag), or a semi-transmissive conductive material such as an alloy of magnesium (Mg) and silver (Ag). The first electrode 120 may be an anode electrode.

Next, a short circuit prevention layer 230 is formed (S804).

More specifically, a short circuit prevention layer 230 is formed on the second side of the bank 220 as shown in FIG. 9G. More specifically, the short circuit prevention layer 230 is formed to fill a space between the interlayer insulating layer 112 formed by the second undercut structure UC2 of the bank 220 and the lower surface 221b of the upper layer 221.

The short circuit layer 230 is an organic film, for example, acrylic resin (acryl resin), epoxy resin (epoxy resin), phenolic resin (phenolic resin), polyamide resin (polyamide resin), polyimide resin (polyimide resin), etc. It can be formed as.

Next, the light emitting layer 130 is formed (S805).

More specifically, as illustrated in FIG. 9H, the light emitting layer 130 is formed on the first electrode 120. The light emitting layer 130 may be formed by a deposition process or a solution process. When the light emitting layer 130 is formed by a deposition process, it may be formed using an evaporation method.

The emission layer 130 may be a white emission layer that emits white light. In this case, the light emitting layer 130 may be a common layer commonly formed in the sub-pixels P1, P2, and P3.

Meanwhile, in 9h, the light emitting layer 130 is illustrated as a common layer commonly formed in the plurality of sub-pixels P1, P2, and P3, but is not limited thereto. The emission layer 130 may be formed of a red emission layer that emits red light, a green emission layer that emits green light, and a blue emission layer that emits blue light. In this case, the light emitting layer 130 may be patterned for each sub-pixel P1, P2, P3. For example, a red emission layer may be formed on the first sub-pixel P1, a green emission layer may be formed on the second sub-pixel P2, and a blue emission layer may be formed on the third sub-pixel P3.

Next, the second electrode 140 is formed (S806).

More specifically, the second electrode 140 is formed on the light emitting layer 130 as shown in FIG. 9I. The second electrode 140 may be formed by physical vapor deposition, such as sputtering. Alternatively, the second electrode 140 may be formed using evaporation.

The second electrode 140 may be made of a transparent metal material, a semi-transmissive metal material, or a metal material having high reflectance. When the display device 100 is made of an upper emission method, the second electrode 140 is a transparent metallic material (TCO, transparent conductive material) such as ITO, IZO, or magnesium (Mg), silver ( Ag), or a semi-transmissive conductive material, such as an alloy of magnesium (Mg) and silver (Ag). When the display device 100 is made of a lower emission method, the second electrode 140 is a stacked structure of aluminum and titanium (Ti/Al/Ti), a stacked structure of aluminum and ITO (ITO/Al/ITO), and an Ag alloy. , And Ag alloy and ITO stacked structure (ITO / Ag alloy / ITO) may be formed of a high reflectivity metal material. The Ag alloy may be an alloy such as silver (Ag), palladium (Pd), and copper (Cu). The second electrode 140 may be a cathode electrode.

Next, an encapsulation film 150 is formed (S807).

More specifically, an encapsulation film 150 is formed on the second electrode 140 as shown in FIG. 9J.

The encapsulation film 150 may include a first inorganic film 151 and an organic film 152. In one embodiment, the encapsulation film 150 may further include a second inorganic film 153.

The first inorganic layer 151 is formed to cover the second electrode 140. The organic layer 152 is formed on the first inorganic layer 151 and prevents particles from penetrating the first inorganic layer 151 and entering the emission layer 130 and the second electrode 140. It is preferably formed to a sufficient thickness. The second inorganic layer 153 is formed to cover the organic layer 152. The second inorganic film 153 may be omitted.

Each of the first and second inorganic films 151 and 153 may be formed of silicon nitride, aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride, silicon oxide, aluminum oxide, or titanium oxide. The first and second inorganic layers 151 and 153 may be deposited by a chemical vapor deposition (CVD) technique or an atomic layer deposition (ALD) technique, but are not limited thereto.

The organic film 152 may be formed of an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin. The organic layer 152 may be formed by vapor deposition, printing, or slit coating using an organic material, but is not limited thereto, and the organic layer 152 is inkjet (ink- jet) process.

Next, a color filter 160 is formed (S808).

More specifically, the color filter 160 is formed on the second inorganic layer 153 as shown in FIG. 9K. The color filter 160 includes a first color filter CF1 disposed to correspond to the first sub-pixel P1, a second color filter CF2 and a third sub-pixel disposed to correspond to the second sub-pixel P2. A third color filter CF3 disposed to correspond to (P3) may be included. The first color filter CF1 may be a red color filter that transmits red light, the second color filter CF2 may be a green color filter that transmits green light, and the third color filter CF3 may be blue light. It may be a blue color filter that transmits.

10A to 10C relate to a display device according to another exemplary embodiment of the present invention, which relates to a head mounted display (HMD) device. 10A is a schematic perspective view, FIG. 10B is a schematic plan view of a VR (Virtual Reality) structure, and FIG. 10C is a schematic cross-sectional view of an Augmented Reality (AR) structure.

10A, the head mounted display device according to the present invention includes a storage case 10 and a head mounting band 30.

The storage case 10 houses components such as a display device, a lens array, and an eyepiece therein.

The head mounting band 30 is fixed to the storage case 10. The head mounting band 30 is illustrated to be formed so as to surround the top and both sides of the user's head, but is not limited thereto. The head-mounted band 30 is for fixing the head-mounted display to the user's head, and can be replaced with a frame or helmet-shaped structure.

As can be seen in FIG. 10B, a head mounted display device having a VR (Virtual Reality) structure according to the present invention includes a display device 12 for the left eye, a display device 11 for the right eye, a lens array 13, and a left eyepiece ( 20a) and the right-eye eyepiece 20b.

The left-eye display device 12, the right-eye display device 11, the lens array 13, and the left-eye eyepiece 20a and the right-eye eyepiece 20b are housed in the storage case 10 described above.

The left-eye display device 12 and the right-eye display device 11 may display the same image, in which case the user can watch the 2D image. Alternatively, the left-eye display device 12 may display a left-eye image and the right-eye display device 11 may display a right-eye image, in which case the user can view a stereoscopic image. Each of the display device 12 for the left eye and the display device 11 for the right eye may be formed of the display devices according to FIGS. 1 to 7 described above. At this time, in FIG. 1 to FIG. 7, an upper portion corresponding to a surface on which an image is displayed, for example, a color filter 160 faces the lens array 13.

The lens array 13 may be provided between the left eyepiece lens 20a and the left eye display device 12 while being spaced apart from each of the left eyepiece lens 20a and the left eye display device 12. That is, the lens array 13 may be positioned in front of the left-eye eyepiece 20a and behind the left-eye display 12. Further, the lens array 13 may be provided between the right-eye eye lens 20b and the right-eye display device 11 while being spaced apart from each of the right-eye eye lens 20b and the right-eye display device 11. That is, the lens array 13 may be positioned in front of the right-eye eyepiece lens 20b and behind the right-eye display device 11.

The lens array 13 may be a micro lens array. The lens array 13 may be replaced with a pin hole array. The image displayed on the left eye display device 12 or the right eye display device 11 due to the lens array 13 may be enlarged to the user.

The left eye LE of the user may be located in the left eyepiece 20a, and the right eye RE of the user may be located in the right eyepiece 20b.

As can be seen in FIG. 10C, the head mounted display device of the AR (Augmented Reality) structure according to the present invention includes a left eye display device 12, a lens array 13, a left eyepiece 20a, and a transmissive reflector 14 , And a transmission window (15). For convenience, only the left eye configuration is shown in FIG. 10C, and the right eye configuration is the same as the left eye configuration.

The left-eye display device 12, the lens array 13, the left-eye eyepiece 20a, the transmissive reflecting portion 14, and the transmissive window 15 are housed in the aforementioned storage case 10.

The display device 12 for the left eye may be disposed on one side, for example, the upper side of the transmissive reflector 14 without covering the transmissive window 15. Accordingly, the left eye display device 12 may provide an image to the transmissive reflector 14 without obscuring the external background seen through the transmissive window 15.

The left eye display device 12 may be formed of the display devices according to FIGS. 1 to 7 described above. At this time, in FIG. 1 to FIG. 7, an upper portion corresponding to a surface on which an image is displayed, for example, the color filter 160 faces the transmissive reflector 14.

The lens array 13 may be provided between the left eyepiece 20a and the transmissive reflector 14.

The left eye of the user is located in the left eye eyepiece 20a.

The transmissive reflector 14 is disposed between the lens array 13 and the transmissive window 15. The transmissive reflector 14 may include a reflective surface 14a that transmits a portion of light and reflects another portion of light. The reflective surface 14a is formed such that the image displayed on the left eye display device 12 proceeds to the lens array 13. Accordingly, the user can view both the external background and the image displayed by the left eye display device 12 through the transparent layer 15. That is, since the user can view the virtual image and the background of the reality as a single image, augmented reality (AR) can be implemented.

The transmission layer 15 is disposed in front of the transmission reflection portion 14.

The embodiments of the present invention have been described in more detail with reference to the accompanying drawings, but the present invention is not necessarily limited to these embodiments, and may be variously modified without departing from the technical spirit of the present invention. . Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of protection of the present invention should be interpreted by the claims, and all technical spirits within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

100: display device
110: substrate TFT: driving thin film transistor
112: interlayer insulating film 120: first electrode
130: light emitting layer 140: second electrode
150: sealing film 151: the first inorganic film
152: organic film 153: second inorganic film
160: color filter 220: bank
230: short circuit protection layer

Claims (13)

A substrate having a first sub-pixel and a second sub-pixel;
A bank provided on the substrate and having an undercut structure in which the width of the lower surface is smaller than the width of the upper surface;
A first electrode provided on the substrate and the bank and disconnected between the first sub-pixel and the second sub-pixel by an uncut structure of the bank;
A light emitting layer provided on the first electrode; And
It includes a second electrode provided on the light emitting layer,
The first electrode formed on the bank is connected to a first electrode formed in a region in which the bank is not formed on the first side, and is formed in a region in which the bank is not formed on a second side facing the first side. A display device that is disconnected from one electrode. According to claim 1,
The bank is a display device having an undercut structure on the first side and the second side. According to claim 2,
The bank has a first separation distance between the bottom surface of the substrate and the upper layer at the first side, and a second separation distance between the bottom surface of the substrate and the upper layer at the second side,
A display device having different distances between the first separation distance and the second separation distance. According to claim 1,
The bank,
A lower layer provided on the substrate and having a first width; And
A display device provided on the lower layer and including an upper layer having a second width greater than the first width. According to claim 4,
The lower layer is made of an inorganic material, and the upper layer is a display device made of an organic material. According to claim 4,
The upper layer is a display device having a round shape with a convex upper surface. According to claim 4,
The lower layer,
A first layer provided on the substrate and having the first width; And
A display device provided on the first layer and including a second layer having a third width smaller than the first width. The method of claim 7,
The upper layer includes a first end formed on the first side and a second end formed on the second side, and the second layer includes a third end formed on the first side and a fourth end formed on the second side. To form,
The distance between the fourth end of the second layer and the second end of the upper layer is smaller than the distance between the third end of the second layer and the first end of the upper layer. According to claim 4,
The bank is a display device having an undercut structure on the second side. The method of claim 9,
The lower layer,
It is provided on the substrate, and includes a first layer having the first width,
The upper layer includes a first end formed on the first side and a second end formed on the second side, and the first layer has a fifth end formed on the first side and a sixth end formed on the second side. Including,
A display device having a distance between a sixth end of the first layer and a second end of the upper layer is smaller than a distance between a fifth end of the first layer and a first end of the upper layer. According to claim 1,
And a short circuit preventing layer provided on the second side of the bank. The method of claim 11,
The short circuit layer is formed on the second side of the bank to fill a space between the substrate and the lower surface of the upper layer. The method of claim 12,
The short circuit preventing layer covers the end of the first electrode.

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