KR102172898B1 - Display Device With Integrated Touch Screen and Method for Manufacturing The Same - Google Patents

Abstract

According to an aspect of the present invention, a touch screen integrated display device includes: a gate electrode formed on a substrate; An active layer formed on the gate electrode; A source electrode formed on the active layer and connected to the active layer through a contact hole of an etch stopper exposing the active layer; A first protective layer formed on the source electrode; A second protective layer formed on the first protective layer; A pixel electrode formed on the second passivation layer and connected to the active layer through a contact hole of the second passivation layer exposing the active layer; A first connection line formed on the second passivation layer at a position corresponding to the source electrode and formed of the same material as the pixel electrode; A metal pad formed on a second connection wire formed on the first connection wire and a pixel electrode formed in a contact hole of a second protective layer exposing the active layer and formed of the same material as the second connection wire ; A third protective layer formed on the second connection line, the pixel electrode, and the metal pad; And a common electrode formed on the third protective layer and connected to the second connection wire through a contact hole exposing the second connection wire.

Description

Display device with integrated touch screen and method for manufacturing the same

The present invention relates to a display device, and more particularly, to a touch screen integrated display device.

The touch screen is a liquid crystal display, field emission display (FED), plasma display panel (PDP), electroluminescence device (EL), electrophoretic display device. It is a type of input device installed in an image display device such as, for example, that a user presses (presses or touches) a touch sensor in a touch screen while viewing the image display device to input predetermined information.

In particular, in recent years, in order to slim portable terminals such as smartphones and tablet PCs, the demand for an in-cell type touch screen-integrated display device that incorporates elements constituting a touch screen inside the display device has increased. have.

Hereinafter, a conventional in-cell type touch screen integrated display device will be described with reference to FIG. 1.

1 is a cross-sectional view of a general touch screen integrated display device. As shown in FIG. 1, a general touch screen integrated display device includes a substrate 100, a thin film transistor as a switching element, a first protective layer 134, a second protective layer 140, a pixel electrode 151, and a connection wiring ( 161, a third protective layer 170, and a common electrode 181 are included.

The thin film transistor is formed in a unit pixel region and includes a gate electrode 110, a gate insulating layer 120, an active layer 130, an etch stopper 131, a source electrode 132, and a drain electrode 133. .

The first protective layer 134 and the second protective layer 140 are formed on the thin film transistor, and in particular, the second protective layer 140 is formed of photo acryl.

The pixel electrode 151 is used as an electrode for driving a display, and is connected to the drain electrode 133 of the thin film transistor through a contact hole formed in the second passivation layer 140.

The connection wiring 161 is formed of a metal material, is formed on the second protective layer 140, and applies a display driving signal and a touch driving signal to the common electrode 181. The third passivation layer 170 is formed on the connection line 161, the pixel electrode 151 and the second passivation layer 140.

The common electrode 181 is formed on a layer different from the pixel electrode 151 and is used as an electrode for driving a display by forming an electric field together with the pixel electrode 151 in the display driving mode, and sensing a touch in the touch driving mode. Used as a touch electrode.

On the other hand, in the area A shown in FIG. 1, when the connection wiring 161 made of metal is deposited directly on the second protective layer 140 formed of photoacrylic, a subsequent process after deposition due to poor adhesion between the metal and photoacrylic. During this time, a filling problem may occur, and there is a possibility that the connection wiring 161 may be lost.

Even if the connection wiring 161 is not lost due to the peeling problem, if the peeling problem occurs at the boundary of the adhesive surface, contamination may occur at the boundary of the adhesive surface due to the etching solution and the peeling solution during the etching and peeling process. Additional cost and time are consumed for processing.

If a buffer passivation layer is formed between the second protective layer 140 and the connection wiring 161 to solve the filling problem, the filling problem can be solved, but cost and time are consumed according to an additional process.

In addition, in region B shown in FIG. 1, when a contact hole for connecting the pixel electrode 151 and the drain electrode 133 is formed, the step difference between the contact hole 141 is large or the first passivation layer 134 is reversed. If there is an abnormality such as a taper, a disconnection of the pixel electrode 151 may occur at the connection portion with the drain electrode 132, and the disconnected portion is exposed to an etching solution or a peeling solution, so that the drain electrode 133 is lost. Problems can arise.

In addition, as shown in the connection portion between the pixel electrode 151 and the drain electrode 133 in FIG. 1, a problem in that touch sensitivity decreases may occur due to capacitance due to overlap between the drain electrode and the gate electrode.

The problems of the general touch screen integrated display device described above are summarized as follows.

First, a peeling problem may occur due to poor adhesion between the second protective layer formed of photoacrylic and the connection wiring made of a metal material, and the peeling problem causes loss of the connection wiring or contamination of the boundary of the bonding surface.

Second, when a buffer passivation layer is used to solve the problem of peeling between photoacrylic and metal, cost and time are consumed due to an additional process.

Third, if the step difference between the contact hole for connecting the pixel electrode and the drain electrode is large, or if reverse taper occurs in the first protective layer, disconnection of the pixel electrode may occur, and the drain electrode of the disconnected portion is formed with an etching solution and a peeling solution. Loss may occur.

Fourth, touch sensitivity may be lowered due to capacitance due to overlap between the drain electrode and the gate electrode.

The present invention is to solve the above-described problems, and provides a touch screen integrated display device capable of improving the filling problem, preventing disconnection of a pixel electrode and loss of a drain electrode, and obtaining high touch sensitivity. Make it a technical task.

In order to achieve the above object, a touch screen integrated display device according to an aspect of the present invention includes: a gate electrode formed on a substrate; An active layer formed on the gate electrode; A source electrode formed on the active layer and connected to the active layer through a contact hole of an etch stopper exposing the active layer; A first protective layer formed on the source electrode; A second protective layer formed on the first protective layer; A pixel electrode formed on the second passivation layer and connected to the active layer through a contact hole of the second passivation layer exposing the active layer; A first connection line formed on the second passivation layer at a position corresponding to the source electrode and formed of the same material as the pixel electrode; A metal pad formed on a second connection wire formed on the first connection wire and a pixel electrode formed in a contact hole of a second protective layer exposing the active layer and formed of the same material as the second connection wire ; A third protective layer formed on the second connection line, the pixel electrode, and the metal pad; And a common electrode formed on the third protective layer and connected to the second connection wire through a contact hole exposing the second connection wire.

A method of manufacturing a touch screen integrated display device according to an aspect of the present invention for achieving the above object comprises: forming a gate electrode on a substrate; Forming an active layer on the gate electrode; Forming a source electrode connected to the active layer on the active layer through a contact hole of an etch stopper exposing the active layer; Forming a first protective layer on the source electrode; Forming a second protective layer on the first protective layer; A pixel electrode connected to the active layer is formed on the second protective layer through a contact hole of a second protective layer exposing the active layer, and formed on the second protective layer at a position corresponding to the source electrode And forming a first connection line formed of the same material as the pixel electrode; Forming a second connection wire on the first connection wire and forming a metal pad on the pixel electrode formed in the contact hole of the second passivation layer; Forming a third protective layer on the second connection line, the pixel electrode, and the metal pad; And forming a common electrode connected to the second connection wire on the third protective layer.

According to the present invention, when forming a pixel electrode in an integrated touch screen display device, the same material as the pixel electrode is additionally formed between the second protective layer formed of photoacrylic and the connection wiring made of a metal material, and between the second protective layer and the connection wiring. There is an effect that can solve the peeling problem that may occur.

In addition, according to the present invention, since the wire to be added is the same material as the pixel electrode and is formed by the same process as the pixel electrode, there is an effect of solving the filling problem without adding a process.

In addition, according to the present invention, when forming the second connection wiring of the touch screen integrated display device, the same material as the second connection wiring is formed on the pixel electrode in the contact hole area as well, so that the pixel electrode that can occur at the connection portion between the pixel electrode and the drain electrode There is an effect of preventing loss of a drain electrode that may occur due to disconnection of the pixel electrode or disconnection of the pixel electrode.

Further, according to the present invention, it is possible to obtain high touch sensitivity by reducing a capacitance that may occur due to overlapping of a gate electrode and a drain electrode in the touch screen integrated display device.

1 is a cross-sectional view of a general touch screen integrated display device;
2 to 9 are cross-sectional views illustrating a method of manufacturing a touch screen integrated display device according to an exemplary embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In describing the embodiments of the present invention, when it is described that a structure is formed on or under another structure, such a substrate is not only a case where the structures are in contact with each other, but a third structure is interposed between these structures. It should be construed as including the case where it is.

Hereinafter, a touch screen integrated display device according to various embodiments of the present disclosure will be described in detail with reference to FIGS. 2 to 9.

2 to 9 are cross-sectional views illustrating a method of manufacturing a display device with integrated touch screen according to an exemplary embodiment of the present invention.

As shown in FIG. 9, a touch screen integrated display device according to an embodiment of the present invention includes a substrate 200, a thin film transistor, a first protective layer 234, a second protective layer 240, and a pixel electrode 251. ), a first connection wire 252, a second connection wire 261, a metal wire 262, a third protective layer 270, and a common electrode 281.

The thin film transistor is formed as a switching element in a pixel region on the substrate 200, and includes a gate electrode 210, a gate insulating layer 220, an active layer 230, an etch stopper 231, and a source electrode 232. .

For example, the gate electrode 210 is formed on the substrate 200 and the active layer 230 is formed on the gate electrode 210. In addition, the source electrode is connected to the active layer 230 through a contact hole of the etch stopper 231 exposing the active layer 230.

In particular, the thin film transistor according to an embodiment of the present invention does not include a drain electrode.

The first passivation layer 234 is formed on the thin film transistor to protect the thin film transistor, and may be formed as a passivation layer. The second protective layer 240 is formed on the first protective layer, and may be formed of photoacrylic.

The pixel electrode 251 is formed on the second passivation layer 240 and is connected to the active layer 230 through a contact hole of the second passivation layer 240 exposing the active layer 230. That is, the pixel electrode 251 according to the present invention is characterized in that it is directly connected to the active layer 230 without passing through the drain electrode.

In this way, the contact hole of the second passivation layer 240 is located at the portion where the gate electrode 210 and the active layer 230 overlap, that is, the upper portion of the channel, and the portion to be covered by the black matrix is reduced, so that the aperture ratio is reduced. It increases compared to before.

In addition, if the pixel electrode 251 is directly connected to the active layer 230 without a drain electrode, there is no overlap area between the drain electrode and the gate electrode, so that initial capacitance is significantly reduced. The touch sensitivity increases due to the decrease in capacitance.

Here, the pixel electrode 251 is used as an electrode for driving a display, and may be formed of a transparent conductor such as ITO (Indium Tin Oxide).

The first connection wiring 252 is formed on the second passivation layer 240 at a position corresponding to the source electrode 231 and is spaced apart from the first pixel electrode 251. Here, the first connection wiring 252 is made of the same material as the pixel electrode 251 and is formed on the same layer.

In other words, when the first connection line 252 is formed between the second protection layer 240 and the second connection line 261, the ITO material forming the first connection line 252 is used as the second protection layer ( Since the adhesion to the photoacrylic forming 240 is good, a peeling problem between the second protective layer 240 and the second connection wiring 261 can be prevented.

In addition, since the first connection wiring 252 is formed of the same material as the pixel electrode 251 and is formed at the same time, there is no need to add a process for forming the first connection wiring 252.

The second connection wire 261 is formed of a metal material on the first connection wire 252 and is electrically connected to the first connection wire 252, and is particularly selected from molybdenum (Mo), aluminum (Al), and copper. It may be formed of any one material or an alloy containing the same. The second connection wiring 261 applies a display driving signal and a touch driving signal to the common electrode 281.

The metal pad 262 is formed of the same material as the second connection line 261 on the pixel electrode 251 formed in the contact hole of the second passivation layer 240 exposing the active layer 230.

In other words, when the metal pad 262 of the same material as the second connection line 261 is formed on the pixel electrode 251, the metal pad 262 is formed on the pixel electrode 251 in the lower region of the first contact hole 241. Connect the disconnected part of) to prevent contact failure. In addition, since the metal pad 262 is the same material as the second connection line 261 and is formed at the same time, there is no need to add a process for forming the panel pad 262.

The third protective layer 270 is formed on the second connection wire 261, the pixel electrode 251, the metal wire 262 and the second protective layer 240, and the second connection wire 261 and the pixel electrode It serves to protect the 251 and the metal wiring 262, and serves to electrically insulate the pixel electrode 251 and the common electrode 281. The third protective layer 270 may be formed as a passivation layer.

The common electrode 281 is formed on the third protective layer 270 and is connected to the second connection wiring 261 through a contact hole of the third protective layer. Here, the common electrode 281 is used as a display driving electrode or a touch electrode. Here, the common electrode 281 may be formed of a transparent conductor such as indium tin oxide (ITO).

The common electrode 281 may include a slit therein. The common electrode 281 and the pixel electrode 251 form a fringe field through a slit, and the liquid crystal may be driven by the fringe field.

Hereinafter, a method of manufacturing a touch screen integrated display device having the above-described configuration according to various embodiments will be described in detail with reference to FIGS. 2 to 9.

First, as shown in FIG. 2, a gate electrode 210, a gate insulating layer 220, and an active layer 230 are formed on the substrate 200, and then the gate insulating layer 220 and the active layer 230 are formed. The step of forming the etch stopper 231 is performed.

Next, as shown in FIG. 3, a step of forming a source electrode 232 connected to the active layer through a contact hole of the etch stopper 231 exposing the active layer on the active layer is performed.

Next, as shown in FIG. 4, a step of forming the first protective layer 234 and the second protective layer 240 on the etch stopper 231 and the source electrode 232 is performed.

Here, the second protective layer may be formed of photo acrylic.

Next, as shown in FIG. 5, a step of forming a contact hole of the second protective layer 240 exposing the active layer 230 on the second protective layer is performed.

Here, in the process of forming a contact hole exposing the active layer 230, a photoresist is formed on the second protective layer 240 and then the formed photoresist is used as a mask to form a contact hole.

Next, as shown in FIG. 6, a pixel electrode 251 connected to the active layer is formed through a contact hole of the second passivation layer 240 exposing the active layer 230, and the second passivation layer is A step of forming the first connection wiring 252 formed at a position corresponding to the source electrode 232 and formed of the same material as the pixel electrode 251 is performed.

Here, the first connection wiring is formed to be spaced apart from the pixel electrode 251 at a position corresponding to the source electrode 232 on the second passivation layer 240. In particular, since the first connection wiring 252 is formed of a transparent conductive layer, good adhesion to the second protective layer 240 formed of photoacrylic can be maintained.

And. The pixel electrode 251 according to the present invention is directly connected to the active layer 230 without passing through the drain electrode, so that the contact hole of the second protective layer 240 overlaps the gate electrode 210 and the active layer 230 The portion that is located above the channel, that is, the portion that must be covered with the black matrix is reduced, so that the aperture ratio increases compared to the previous one.

In addition, since the pixel electrode 251 is directly connected to the active layer 230 without a drain electrode, there is no overlapping area between the drain electrode and the gate electrode, so that the initial capacitance of the gate electrode is significantly reduced. The touch sensitivity increases due to the decrease in capacitance.

Next, as shown in FIG. 7, a second connection line 261 is formed on the first connection line 252, and a metal pad is formed on the pixel electrode 251 formed inside the contact hole of the second protective layer. Perform the step of forming 262.

Here, the second connection wiring and the metal pad are simultaneously formed by the same process, and the metal pad 262 is electrically connected to the pixel electrode 251 in the contact hole region of the second protective layer, so that the pixel electrode under the contact hole Disconnection of (251) can be prevented.

Next, as shown in FIG. 8, a step of forming a third protective layer 270 on the second connection line 261, the pixel electrode 251, and the metal pad 262 is performed.

Next, as shown in FIG. 9, a step of forming a common electrode connected to the second connection wiring 262 on the third protective layer 270 is performed.

In this specification, in the manufacturing method of the touch screen integrated display device, only the process of forming the common electrode has been described, but the spirit of the present invention is not limited thereto, and an additional process for manufacturing the touch screen integrated display device is performed after the common electrode forming process. You can do more.

Those skilled in the art to which the present invention pertains will appreciate that the above-described present invention can be implemented in other specific forms without changing the technical spirit or essential features thereof.

Therefore, it should be understood that the embodiments described above are illustrative in all respects and not limiting. The scope of the present invention is indicated by the claims to be described later rather than the detailed description, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. do.

200: substrate 210: gate electrode
220: gate insulating film 230: active layer
231: etch stopper 232: source electrode
234: first protective layer 240: second protective layer
251: pixel electrode 252: first connection wiring
261: second connection wiring 262: metal pad
270: third protective layer 281: common electrode

Claims (9)

A gate electrode formed on the substrate;
An active layer formed on the gate electrode;
An etch stopper formed on the active layer;
A source electrode formed on the etch stopper and connected to the active layer through a first contact hole of the etch stopper exposing the active layer;
A first protective layer formed on the source electrode;
A second protective layer formed on the first protective layer;
A pixel electrode formed on the second passivation layer and connected to the active layer through the second passivation layer exposing the active layer, the first passivation layer, and a second contact hole of the etch stopper;
A first connection line formed on the second passivation layer at a position corresponding to the source electrode and formed of the same material as the pixel electrode;
A second connection wire formed on the first connection wire and a metal pad formed on the pixel electrode formed in the second contact hole exposing the active layer and formed of the same material as the second connection wire;
A third protective layer formed on the second connection line, the pixel electrode, and the metal pad; And
And a common electrode formed on the third protective layer and connected to the second connection line through a contact hole exposing the second connection line.
The method of claim 1,
The pixel electrode is a touch screen integrated display device, characterized in that formed of a transparent conductor such as ITO (Indium Tin Oxide).
The method of claim 1,
Wherein the first and third protective layers are passivation layers.
The method of claim 1,
The second protective layer is a touch screen integrated display device, characterized in that formed of photo acrylic (PAC).
The method of claim 1,
The pixel electrode and the first connection wire are formed on the same layer. Forming a gate electrode on the substrate;
Forming an active layer on the gate electrode;
Forming an etch stopper on the active layer;
Forming a source electrode connected to the active layer on the etch stopper through a first contact hole of the etch stopper exposing the active layer;
Forming a first protective layer on the source electrode;
Forming a second protective layer on the first protective layer;
A pixel electrode connected to the active layer is formed on the second passivation layer through the second passivation layer exposing the active layer, the first passivation layer, and a second contact hole of the etch stopper, and the second passivation layer Forming a first connection wire made of the same material as the pixel electrode on the protective layer at a position corresponding to the source electrode;
Forming a second connection wire on the first connection wire, and forming a metal pad on the pixel electrode disposed in the second contact hole;
Forming a third protective layer on the second connection wiring, the pixel electrode, and the metal pad; And
And forming a common electrode connected to the second connection wire on the third passivation layer.
The method of claim 6,
The second connection wiring and the metal pad are simultaneously formed by the same process.
The method of claim 6,
The second protective layer is a method of manufacturing a touch screen integrated display device, characterized in that the photo acrylic (PAC). The method of claim 1,
Further comprising a gate insulating layer formed between the gate electrode and the active layer,
The etch stopper is formed on the active layer and the gate insulating layer to contact the active layer and the gate insulating layer,
The first protective layer is formed on the source electrode and the etch stopper to contact the source electrode and the etch stopper on the gate insulating layer.

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