KR20160035161A - Silicon wafer with light emitting diode and display device using the silicon wafer - Google Patents

Abstract

The present invention relates to a silicon substrate having a built-in light emitting diode and a display device using the same. According to one aspect of the present invention, provided is the silicon substrate, where the light emitting diode is mounted, made of a plurality of unit cells comprising a TFT circuit and wires to operate the light emitting diode. The purpose of the present invention is to provide the display device bonded to the silicon substrate where a sapphire substrate and the light emitting diode are mounted.

Description

TECHNICAL FIELD [0001] The present invention relates to a silicon substrate having a light emitting diode and a display device using the same. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to a silicon substrate having a built-in light emitting diode and a display device using the same.

2. Description of the Related Art [0002] As an information-oriented society develops, there have been various demands for a display device for displaying images. Recently, a liquid crystal display (LCD), a plasma display panel (PDP) Various display devices such as an organic light emitting display (OLED) device are being used. Such various display apparatuses include display panels corresponding thereto.

Particularly, a liquid crystal display (LCD) and an organic light emitting display (OLED) can reduce the thickness of the device and enable a large-area light-weighted display. Liquid crystal display devices and organic light emitting display devices are also widely used as portable display devices. However, since both the LCD and the OLED are produced on the basis of a glass or plastic substrate, they are weak in hardness due to the characteristics of the material, require additional protective film, and consume a lot of power. In particular, in the case of a display device having frequent external impacts or movement, such as a portable display device, there are problems such as an additional process for enhancing hardness in applying an LCD or OLED and a battery for smoothly supplying power It is necessary to solve the problem.

In view of the foregoing, an object of the present invention is to provide a display device in which a sapphire substrate and a silicon substrate on which a light emitting diode is mounted are cemented.

It is another object of the present invention to provide a display device for mounting a light emitting diode by etching a silicon substrate and bonding the silicon substrate and the sapphire substrate to protect the device from external scratches.

In order to achieve the above object, in one aspect, the present invention provides a silicon substrate having a plurality of unit cells in which light emitting diodes are mounted and TFT circuits and wirings for operating the light emitting diodes are formed.

According to another aspect of the present invention, there is provided a display device including a silicon substrate having a plurality of unit cells each having a light emitting diode mounted thereon and a TFT circuit for operating the light emitting diode and wirings formed thereon, and a sapphire substrate bonded to the silicon substrate.

As described above, according to the present invention, it is possible to provide a display device using low power consumption by providing a silicon substrate to which a light emitting diode is coupled.

According to the present invention, the sapphire substrate and the silicon substrate are bonded together to provide an effect of increasing the strength against external impact.

1 is a view showing a smart watch as a kind of wearable display.
2 is a view showing the result of etching a silicon substrate according to an embodiment of the present invention.
3 is a view illustrating a driving electrode portion and a TFT element formed in a silicon substrate according to an embodiment of the present invention.
4 is a diagram illustrating a light emitting diode mounted on a unit cell according to an embodiment of the present invention.
FIG. 5 is a view showing a result of forming a black matrix according to an embodiment of the present invention.
6 is a view showing a result of attaching an upper substrate according to an embodiment of the present invention.
7 is a view illustrating a light emitting diode mounted on one unit cell according to an embodiment of the present invention and a wiring connected to the unit cell.
8 to 10 are views showing a TFT for driving a light emitting diode mounted in one unit cell according to an embodiment of the present invention, a data line and a gate line connected to the TFT, and a VDD line connected to the TFT.
11 is a plan view illustrating an example in which a light emitting diode, a wiring, and a TFT are formed on a silicon substrate according to an embodiment of the present invention.
12 is a perspective view showing a three-dimensional structure in which a light emitting diode, a wiring, and a TFT are formed on a silicon substrate according to an embodiment of the present invention.
13 is a cross-sectional view illustrating the structure of a light emitting diode formed on a silicon substrate according to an embodiment of the present invention.
FIG. 14 is a diagram showing a portion where a reflective layer is formed in each unit cell according to an embodiment of the present invention. FIG.
FIG. 15 is a diagram illustrating an example in which the sizes of RGB light emitting diodes formed in each unit cell according to an embodiment of the present invention are different.
16 is a view showing the configuration of three RGB light emitting diodes formed in each unit cell according to an embodiment of the present invention.
17 is a view showing a configuration in which a zener diode is mounted in each unit cell according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In the drawings, like reference numerals are used to denote like elements throughout the drawings, even if they are shown on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the components from other components, and the terms do not limit the nature, order, order, or number of the components. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; intervening "or that each component may be" connected, "" coupled, "or " connected" through other components.

1 is a view showing a smart watch as a kind of wearable display. The smart watch 10 transmits and receives information in real time and outputs the transmitted and received information to the display screen 11. Wearable displays, such as smart watches, have a high power consumption due to their constantly transmitting and receiving information and therefore have to be charged frequently. The power consumption of the products released up to now guarantees up to 3 ~ 5 working hours. The power consumption of the display screen 11 depends on the power consumption for driving the backlight unit (LCD) in the case of an LCD, and also in the case of the OLED display using the OLED element, There is a disadvantage that power consumption is high. On the other hand, in the case of an LCD, the visibility is deteriorated when the external illuminance due to the sunlight is high, and therefore, the required luminance is much higher than that of an ordinary indoor display device. That is, when the brightness is not high in the daytime, the screen of the LCD display device looks very dark. On the other hand, in the case of an OLED, the polarizing film may adhere to the upper part due to the visibility due to the reflection by the external light and the internal reflection electrode. Therefore, both of the LCD and the OLED require high power consumption when used in a high- do. In addition, due to the nature of the wearable display, scratches frequently occur due to external impact due to its attachment to the body. Since LCD and OLED are produced on the basis of glass or plastic substrate, the hardness is weak and an additional protective film is required .

In this specification, a display device using a new display device for achieving low power consumption, improved visibility, and advanced product in realizing a wearable display, which is one of major display items in the future, is proposed. For this purpose, a display device in which an electrode portion for light emission is formed on a silicon wafer and a light emitting diode of red / green / blue (RGB) is coupled to the electrode portion on the substrate is implemented.

2 is a view showing the result of etching a silicon substrate according to an embodiment of the present invention. A bare silicon wafer 100 is etched to form a unit cell 110 for each pixel. Each unit cell 110 may have an RGB light emitting diode mounted thereon.

3 is a view illustrating a driving electrode portion and a TFT element formed in a silicon substrate according to an embodiment of the present invention. An electrode portion and a TFT element capable of driving the unit cell 110 are formed. The silicon substrate mounts the light emitting diode to the lower substrate. The driving electrode portion forms an electrode portion and a TFT which drive the light emitting diode formed in each unit cell 110. [ When forming the electrode, the etching cavity can also provide a reflector function by metal deposition. More specifically, in FIG. 3, 120 designates a first power supply line, and 130 designates a second power supply line. The first power supply line and the second power supply line are respectively connected to the light emitting diode by wiring for driving the light emitting diode of the unit cell, or by a TFT which drives the light emitting diode to drive the light emitting diode. The details of the connection of electric wiring and the configuration of the TFT will be described later. The first power supply line and the second power supply line may be a gate wiring, a data wiring, or a VDD power wiring, which will be described later.

The driving electrode portion and the TFT element shown in FIG. 3 are formed, and a metal material related to the driving electrode portion or the TFT element can be formed in the partition wall of the unit cell. So that the light of the light emitting diode can be emitted to the outside through the reflection layer of the silicon substrate with the above-described reflection layer (reflector). As a result, the light efficiency of the light emitting diode can be increased. In addition, the reflective layer of the metallic material formed on the partition wall in the unit cell improves the power of the power source applied to the light emitting diode.

4 is a diagram illustrating a light emitting diode mounted on a unit cell according to an embodiment of the present invention. The RGB light emitting diodes 190 may be mounted on the unit cells and the three RGB light emitting diodes may be mounted on one unit cell. The light emitting diode is electrically connected to the previously formed electrode driver and the TFT. The mounting of the light emitting diode on the unit cell means that the light emitting diode is electrically connected to the driving electrode portion and the portion formed by the TFT. The light emitting diode is mounted in the etched unit cell, and can be connected to the TFT formed on the partition formed on the unit cell and the wiring formed on the lower part of the unit cell.

FIG. 5 is a view showing a result of forming a black matrix according to an embodiment of the present invention. A black matrix is formed to protect the electrode portions formed in the unit cells. The black matrix is formed to protect the electrode portions when the sapphire substrate as the upper substrate is coupled. A black matrix is formed on barrier ribs for separating each unit cell in which light emitting diodes are formed.

6 is a view showing a result of attaching an upper substrate according to an embodiment of the present invention. The upper substrate can be attached using a sapphire substrate having high hardness. Since the sapphire substrate 200 is bonded onto the black matrix 150, the sapphire substrate 200 does not directly contact the light emitting diode or the electrode portion.

7 is a view illustrating a light emitting diode mounted on one unit cell according to an embodiment of the present invention and a wiring connected to the same. 7, the data line Data and the gate line Gate are connected to a switching transistor 710 and the drain of the switching transistor 710 is connected to a gate region of a driving transistor 720 . On the other hand, the source of the driving TR 720 is connected to the driving power source VDD (or EVDD), the drain of the driving TR 720 is connected to the light emitting diode (LED) 190 and the other of the light emitting diode 190 is connected to VSS (Or EVSS). Here, VDD may be configured as an anode and VSS may be configured as a cathode.

3 to 7, a unit cell formed through etching includes at least one light emitting diode mounted thereon and a TFT circuit to which the light emitting diode is connected. Further, gate wirings, data wirings, and driving power supply wirings, which are connected to the TFT circuits in each unit cell, are formed on the barrier ribs of the unit cells or in the lower portion of the unit cells. Such wirings may be formed by forming a TFT circuit and its associated wiring on a silicon substrate, then covering the silicon again, etching it, and then forming an electrode portion. The light emitting diodes mounted in FIG. 5 are placed in the unit cell in one or more numbers and are connected to the TFT circuit. As shown in FIG. 5, a black matrix is located between the plurality of unit cells, more specifically, on the partition walls of the unit cells. One end of the light emitting diode 190 is connected to the TFT circuit as shown in FIG. 7, and the other end is connected to the base power supply line VSS. Accordingly, the base power supply electrode material layer 840 to which VSS is applied may be formed on the silicon substrate. This includes embodiments in which the VSS to which the base voltage is applied is formed in the form of a surface electrode on the silicon substrate as a transparent cathode. However, the present invention is not limited to this. VSS may be formed on a silicon substrate or may be formed with a TFT circuit under silicon by a separate TFT circuit or wiring, depending on the structure of the wiring.

8 to 10 are views showing a TFT for driving a light emitting diode mounted in one unit cell according to an embodiment of the present invention, a data line and a gate line connected to the TFT, and a VDD line connected to the TFT.

8, gate wirings 810 are formed laterally and data wirings 820 are formed vertically to form switching TR as 710. [ The gate of the switching TR 710 is connected at the gate wiring 810, and the source of the switching TR 710 is connected at the data wiring 820. On the other hand, the drain of the switching TR 710 is connected to the gate of the driving TR 720 to be formed in FIG.

Fig. 9 shows that a gate insulating film is formed on the formed portion of the switching TR 710 and the driving TR 720 is formed. The gate of the driving TF 720 is formed simultaneously with the same material as the drain material of the switching TR 710 according to the circuit configuration of FIG. 7 as described above.

10 shows that the VDD 830 is connected to the source of the driving TR 720 and the light emitting diode 190 is connected to the drain. The other side of the light emitting diode is connected to a VSS to be described later.

11 is a plan view illustrating an example in which a light emitting diode, a wiring, and a TFT are formed on a silicon substrate according to an embodiment of the present invention. Reference numeral 1100 denotes a structure of the TFTs 710 and 720, and the light emitting diode 190 is connected to the TFT. Although not shown in the figure, the VDD 830 wiring is connected to the source of the driving TR 720. On the other hand, the other side of the light emitting diode 190 is connected to the VSS 840 formed on the front side of the unit cells. In order to transmit the light of the light emitting diode of the unit cell, VSS may be formed on the entire surface of the silicon substrate with a clear cathode.

12 is a perspective view showing a three-dimensional structure in which a light emitting diode, a wiring, and a TFT are formed on a silicon substrate according to an embodiment of the present invention. An enlarged view 1101 of FIG. 11 is shown in FIG. The light emitting diode 190 is connected to the TFT circuit 1110 and the cathode 840 and can emit light in accordance with the data line for driving the TFT circuit 1100 and the electricity applied to the gate line. The anode 1210 is connected to the TFT circuit 1110 and the electricity of the anode 1210 is applied to the light emitting diode 190 according to the driving of the TFT circuit 1110. The front cathode 840 is formed on the unit cell in a transparent manner.

13 is a cross-sectional view illustrating the structure of a light emitting diode formed on a silicon substrate according to an embodiment of the present invention. Sectional views taken along lines I-I 'and II-II' of FIG. 10. I-I 'shows the configuration of the switching TR, and II-II' shows the configuration of the driving TR. 1310 and 1320 are insulating films. And functions as a gate insulating film or an interlayer insulating film. Since the light emission of the light emitting diode formed in each unit cell can be controlled by using the switching TR and the driving TR, various colors can be provided. Further, even when the RGB light emitting diodes are included in one unit cell to emit white light, the emission of white light for each unit cell can be selectively controlled.

In the device of the display device according to an embodiment of the present invention, the lower substrate may be a silicon wafer, and the upper substrate may be a sapphire wafer. As previously noted, the silicon wafer is etched to an appropriate thickness to form a unit cell. The unit cell may be designed to be variable in accordance with the PPI (pixel per inch) condition, and the light emitting diode may be mounted in each unit cell. For example, three light emitting diodes, which are RGB light emitting diodes, may be included in one unit cell in order to realize white color. In order to implement RGB colors, Color light emitting diodes can be independently mounted in the unit cell. Meanwhile, the cavity formed by etching the unit cell may be formed of a reflective material with a metal material. This reflective layer may be formed in an isolation region. Such a reflective layer can be formed at the same time in the process of forming the driving electrode portion and the TFT circuit.

FIG. 14 is a diagram showing a portion where a reflective layer is formed in each unit cell according to an embodiment of the present invention. FIG. FIG. 14 shows that the light generated from the light emitting diode 190a is reflected by the reflection layer 1410 formed at the same time as the driving electrode portion and the TFT circuit are formed in the configurations of FIGS. 3 to 6. The light emitting diode 190a is electrically connected to the reflective layer 1410 connected to the driving electrode portion and is also electrically connected to the VSS (common electrode) in close contact with the sapphire substrate 200. [ The reflective layer 1410 may be a structure that completely encloses the inside of the cavity, and may form a common reflective surface in the cavity. In FIG. 14, one light emitting diode is formed in one unit cell, and the luminous efficiency can be enhanced by the metallic reflective material formed on the partition wall of the unit cell. In addition, since the light of other adjacent light emitting diodes is completely blocked due to the partition walls of the unit cells, it is possible to provide a display device with no color mixture and high visibility. It is possible to provide a display device that reproduces various colors when one light emitting diode is mounted in a unit cell and the TFT circuit is controlled by gate wiring and data wiring.

The size of the light emitting diode formed in the cavity may vary depending on the luminance and resolution to be implemented in the display device, and the size of each of the R, G, and B LEDs may have a specific ratio in consideration of the white balance for white implementation .

The cavity may be filled with air or a nitrogen inert gas, or may be filled with an optical resin with transparency. A main electrode wiring portion is formed in an attachment region of the upper substrate and the lower substrate and a black matrix material can be mounted for minimizing external light reflection of the electrode wiring portion and for protecting the electrode portion. On the other hand, it is possible to designate a specific region of the lower substrate to mount the Zener diode and to prevent static electricity flowing into the light emitting diode. The zener diode is shown in Fig.

FIG. 15 is a diagram illustrating an example in which the sizes of RGB light emitting diodes formed in each unit cell according to an embodiment of the present invention are different. For convenience of explanation, the wiring connected to each light emitting diode is not shown. Reference numerals 1501, 1502, and 1503 denote unit cells, respectively. The size of the RGB light emitting diodes maintains a 1: 2: 1 configuration based on the area. The size of the green light emitting diode 1512 may be doubled in comparison with the sizes of the red light emitting diode 1511 and the blue light emitting diode 1513. The size of the light emitting diodes can be determined in consideration of the luminance of the color to be emitted. That is, in the case where a specific color has a characteristic of weakly emitting light, it is possible to configure the size to compensate for such a luminance variation.

16 is a view showing the configuration of three RGB light emitting diodes formed in each unit cell according to an embodiment of the present invention. For convenience of explanation, the wiring connected to each light emitting diode is not shown. Three RGB light emitting diodes are formed in each of the unit cells 1601, 1602, and 1603 to realize a white color. This is applicable when displaying the display with only white. That is, in order to realize a white display, RGB light emitting diodes are combined without using a white light emitting diode, and the white light is outputted by being mounted in one unit cell. In order to simultaneously drive the RGB light emitting diodes located in the unit cell in FIG. 16, the same can be connected to the VDD wiring previously described.

17 is a view showing a configuration in which a zener diode is mounted in each unit cell according to an embodiment of the present invention. In Fig. 17, a light emitting diode 1710 and a zener diode 1720 are mounted in one unit cell 1701. Fig. The zener diode 1720 is connected to the light emitting diode 1710 and provides a function of preventing the static electricity generated in the light emitting diode 1710. When static electricity flows into the light emitting diode 1710 in the unit cell, there arises a problem in driving the light emitting diode 1710 and the TFT circuit connected thereto, so that a luminescent spot or a dark spot may occur in the corresponding unit cell. When the zener diode 1720 is mounted in the unit cell, the static electricity flowing into the light emitting diode 1710 is blocked to provide reliability. The zener diode 1720 may be positioned within the unit cell so as not to interfere with the light of the light emitting diode 1710. In order to prevent the LED element from being damaged by static electricity, the Zener diode may be mounted as shown in FIG. 17, but the present invention is not limited thereto. When the ESD resistance of the LED element is good, it is not necessary to mount the zener diode. Therefore, the zener diode can be mounted in consideration of the characteristics of the LED element.

A display device having a unit cell structure in which a light emitting diode is mounted as in the present invention can improve a light efficiency and visibility by forming a cavity in a unit cell and inducing reflection in each unit cell. In addition, a black matrix for protecting the electrode portions is formed in the adhesion region between the substrates to prevent reflection of the electrode wiring, and as a result, visibility can be improved. And a sapphire substrate is used as an upper substrate to apply to a device such as a wearable display that is easily exposed to the outside, thereby making it possible to manufacture a high-hardness product.

In the case of implementing the present invention, since the silicon wafer substrate is used as the lower substrate, the efficiency of the electrode unit laminated structure can be improved and the thermal conductivity can be improved to improve the efficiency. Further, the unit cells are configured to prevent color mixing of light emitted from the light emitting diodes. In addition, by driving the microcurrent, a low power consumption effect is realized.

In the embodiment of the present invention as described above, a lower substrate including an electrode portion and a TFT circuit is formed to form a display device, and a unit cell is formed on a lower substrate to mount the RGB light emitting diode. The lower substrate easily forms an electrode portion and a TFT circuit, and a silicon wafer which can be easily etched due to heat transfer efficiency and crystal characteristics can be applied.

A high-strength substrate such as a sapphire substrate can be used as an upper substrate to protect each light-emitting diode and an electrode or a circuit. The upper substrate can be used for a wearable device which can easily be exposed to the outside since a material strong against scratches, pressure, etc. can be used. In the construction of RGB, the size can be variously adjusted as shown in FIG. 16 in consideration of the visibility and the luminance characteristic of each light emitting diode. The color of the light emitting diode of a specific color may be set differently or the reflection layer formed in the unit cell to which the light emitting diode of a specific color is to be mounted may be set differently. The unit cell may also include an air cavity. Through such a configuration, the present invention can provide a display device with low power consumption, improve the visibility, and provide a display device resistant to an external impact.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. , Separation, substitution, and alteration of the invention will be apparent to those skilled in the art. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

100: silicon substrate 190, 1710: light emitting diode
110, 1501, 1502, 1503, 1601, 1602, 1603:
710: switching transistor 720: driving transistor
810: gate wiring 820: data wiring
830: Driving power supply wiring 840: Base power supply electrode material layer
1720: Zener diode

Claims (11)

A plurality of unit cells mounted with one or more light emitting diodes and including TFT circuits to which the light emitting diodes are connected;
A gate wiring, a data wiring, and a driving power wiring connected to the TFT circuit in the unit cell;
A light emitting diode located in the unit cell and connected to the TFT circuit;
A black matrix located on the partitions of the plurality of unit cells; And
And a base power supply electrode material layer disposed on the unit cell.
The method according to claim 1,
Wherein at least two light emitting diodes are located in the one unit cell.
The method according to claim 1,
Wherein one light emitting diode is located in the one unit cell.
The method of claim 3,
Wherein the light emitting diodes are different in size depending on colors.
The method according to claim 1,
Wherein the unit cell includes a reflective layer which is the same material as any one of the gate wiring, the data wiring, and the driving power supply wiring.
The method according to claim 1,
The TFT circuit includes a driving transistor and a switching transistor,
The data wiring and the gate wiring are respectively connected to a source or drain electrode and a gate of the switching transistor,
The drain or source electrode of the switching transistor is connected to the gate of the driving transistor,
Wherein the driving power supply line is connected to a source or a drain electrode of the driving transistor,
Wherein the light emitting diode is connected to a drain or a source electrode of the driving transistor.
The method according to claim 1,
And a zener diode connected to the light emitting diode in the unit cell.
A unit cell for mounting at least one light emitting diode and a TFT circuit to which the light emitting diode is connected, and a black matrix for protecting a gate wiring, a data wiring, a driving power wiring and a wiring connected to the TFT circuit, A silicon substrate; And
And a sapphire substrate adhered to the silicon substrate.
9. The method of claim 8,
And one light emitting diode is disposed in the one unit cell.
10. The method of claim 9,
Wherein the light emitting diodes are different in size depending on colors.
9. The method of claim 8,
Wherein the unit cell includes a reflective layer which is the same material as any one of the gate wiring, the data wiring, and the driving power supply wiring.

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