KR20110070619A - Method of fabricating display device - Google Patents

Abstract

PURPOSE: A method of fabricating a display device is provided to reduce the generation of a failure and production costs, thereby increasing the productivity. CONSTITUTION: A method of fabricating a display device comprises steps of: forming a flexible substrate(200) on a sacrificial substrate; forming a buffer layer(300) on the flexible substrate; forming a plurality of lines(400) on the buffer layer; forming a sacrificial frame(101) which surrounds the lines; and attaching a support plate under the flexible substrate within the sacrificial frame.

Description

Manufacturing method of display device {METHOD OF FABRICATING DISPLAY DEVICE}

An embodiment relates to a method of manufacturing a display device.

Conventional electrophoretic display devices (EPDs) are excellent in flexibility and portability, and have electrophoresis characteristics such as light weight (Electrophoresis: a phenomenon in which charged particles move toward an anode or a cathode in an electric field). It is a kind of flat panel display.

The electrophoretic display device is a display that forms a thin film transistor array on a thin and bendable base film such as paper or plastic and drives electrophoretic floating particles by a vertical electric field between a pixel electrode and a common electrode of the thin film transistor array. It is a display device that is also expected as paper.

The embodiment is to provide a method of manufacturing a display device that is easy, reduces defects, reduces production costs, and is capable of mass production.

A method of manufacturing a display device according to an embodiment may include attaching a flexible substrate to a sacrificial substrate; Forming a wiring part on the flexible substrate; And etching the sacrificial substrate using an etchant.

A method of manufacturing a display device according to an embodiment may include forming a flexible substrate on a sacrificial substrate; Forming a buffer layer on the flexible substrate; Forming a plurality of wiring units on the buffer layer; Etching a portion of the sacrificial substrate corresponding to the wiring portions using an etchant to form a sacrificial frame surrounding the wiring portions; And attaching a support substrate to the sacrificial frame under the flexible substrate.

In the method of manufacturing the display device according to the embodiment, the sacrificial substrate is etched using an etchant. Accordingly, the sacrificial substrate is uniformly etched, and the bottom surface of the flexible substrate is smoothly exposed.

Accordingly, the method of manufacturing the display device according to the embodiment exposes the lower surface of the flexible substrate by using an etching solution, thereby simplifying the process and enabling mass production. In addition, the manufacturing method of the display device according to the embodiment does not require the use of expensive laser equipment, and therefore can be produced at low cost.

In addition, since the lower surface of the flexible substrate is smoothly exposed, the manufacturing method of the display device according to the embodiment can reduce defects.

In the description of the embodiments, it is described that each substrate, layer, region, part or electrode or the like is formed “on” or “under” of each substrate, layer, region, part or electrode, or the like. In the case, “on” and “under” include both being formed “directly” or “indirectly” through other components. In addition, the upper or lower reference of each component is described with reference to the drawings. The size of each component in the drawings may be exaggerated for the sake of explanation and does not mean the size actually applied.

1 to 11 illustrate a process according to a method of manufacturing an electrophoretic display according to an exemplary embodiment.

1 and 2, the flexible substrate 200 is attached to the sacrificial substrate 100.

The sacrificial substrate 100 is rigid and supports the flexible substrate 200. In more detail, the sacrificial substrate 100 supports the flexible substrate 200 while the electrophoretic display according to the embodiment is formed. The sacrificial substrate 100 may have a plate shape and may have a thickness of about 0.3 mm to about 10 mm.

Examples of the material used as the sacrificial substrate 100 include glass or stainless steel. That is, the sacrificial substrate 100 may be a glass substrate or a stainless steel substrate.

The flexible substrate 200 is attached to the sacrificial substrate 100. In more detail, the flexible substrate 200 may be formed by laminating a resin film on the sacrificial substrate 100.

Alternatively, the flexible substrate 200 may be coated on the sacrificial substrate 100. That is, a material material for forming the flexible substrate 200 is coated on the sacrificial substrate 100, the material material is cured by light such as heat and / or ultraviolet rays, and the flexible substrate 200 is Can be formed.

The flexible substrate 200 is flexible. The flexible substrate 200 may have a thickness relatively smaller than that of the sacrificial substrate 100. The thickness of the flexible substrate 200 may be about 10 μm to about 500 μm.

The flexible substrate 200 may be transparent or opaque. The flexible substrate 200 includes a flexible resin. Examples of the material used as the flexible substrate 200 include polyimide, polymethyl methacrylate (PMMA), polycarbonate (PC), and the like.

Referring to FIG. 3, a buffer layer 300 is formed on the flexible substrate 200. Examples of the material used as the buffer layer 300 may include an inorganic material such as silicon nitride (SiNx). The buffer layer 300 prevents an external gas such as water or oxygen from penetrating into the wiring unit 400 to be formed later.

The buffer layer 300 is formed by a vacuum deposition process. That is, an inorganic material such as silicon nitride is deposited on the flexible substrate 200 by a process such as PECVD or CVD to form the buffer layer 300.

4 to 7, a plurality of wiring units 400 are formed on the buffer layer 300. 4 and 5 illustrate two wiring units 400, but embodiments are not limited thereto. One wiring unit may be formed on the buffer layer 300, and three or more wiring units may be formed.

6 is a circuit diagram illustrating each of the wiring units 400, and FIG. 7 is a cross-sectional view illustrating the thin film transistor TR in detail.

The wiring unit 400 includes a plurality of gate lines 410, a plurality of data lines 420, a plurality of thin film transistors TR, and a plurality of pixel electrodes 440.

The gate lines 410 extend in parallel with each other. The gate lines 410 extend in the first direction. The gate lines 410 extend in parallel with each other. Gate pads 411 are connected to ends of the gate lines 410, respectively.

The gate lines 410 are disposed on the flexible substrate 200. The gate wires 410 are conductors, and examples of the material used as the gate wires 410 may include copper, aluminum, or molybdenum.

The data lines 420 cross the gate lines 410. That is, the data lines 420 extend in a second direction crossing the first direction. The data lines 420 are arranged side by side with each other. The data lines 420 extend parallel to each other. Data pads 421 are connected to ends of the data lines 420, respectively.

The data lines 420 are disposed on the gate insulating layer 435. That is, the gate insulating layer 435 covers the gate lines 410, and the data lines 420 are formed thereon. That is, the gate insulating layer 435 is interposed between the gate lines 410 and the data lines 420.

The data wires 420 are conductors, and examples of the material used as the data wires 420 may include copper, aluminum, or molybdenum.

A plurality of pixel regions P is formed by the gate lines 410 and the data lines 420. That is, the gate lines 410 and the data lines 420 may be boundaries of each pixel area P. In FIG.

The thin film transistors TR are disposed in regions where the gate lines 410 and the data lines 420 cross each other. The thin film transistors TR are driven by a gate signal applied from the gate line 410.

In addition, the thin film transistors TR transmit data signals applied from the data lines 420 to the pixel electrodes 440 by the gate signal. That is, the thin film transistors TR selectively connect the data lines 420 and the pixel electrodes 440 by the gate signal.

As illustrated in FIG. 7, the thin film transistor TR includes a gate electrode 431, a semiconductor layer 432, a source electrode 433, and a drain electrode 434.

The gate electrode 431 extends from the gate wiring. The gate electrode 431 is integrally formed with the gate wiring 410.

The semiconductor layer 432 is disposed corresponding to the gate electrode 431. The semiconductor layer 432 may be disposed on the gate insulating layer 435. The semiconductor layer 432 forms a channel of the thin film transistor TR. Examples of the material used as the thin film transistor TR include amorphous silicon, polysilicon, and the like.

The source electrode 433 is connected to the semiconductor layer 432. The source electrode 433 extends from the data line 420. The source electrode 433 may be in direct contact with the top surface of the semiconductor layer 432.

The drain electrode 434 is connected to the semiconductor layer 432. The drain electrode 434 is spaced apart from the source electrode 433 and may have an island shape. The drain electrode 434 may be in direct contact with the top surface of the semiconductor layer 432.

The drain electrode 434 is connected to the pixel electrode 440.

The channel is formed in the semiconductor layer 432 between the source electrode 433 and the drain electrode 434. In addition, the source electrode 433, the drain electrode 434, and the data line 420 may be formed on the same layer. That is, the source electrode 433, the drain electrode 434, and the data line 420 are made of the same material and are formed at the same time by the same process.

The pixel electrodes 440 are disposed in the pixel regions P, respectively. The pixel electrodes 440 are disposed on the passivation layer 436 covering the data line 420, the source electrode 433, and the drain electrode 434.

The pixel electrodes 440 are respectively connected to the thin film transistors TR. In detail, each pixel electrode 440 is connected to the drain electrode 434 through a contact hole formed in the passivation layer 436. Connected.

The wiring unit 400 may be formed by a general mask process. For example, a first metal layer is formed on the flexible substrate 200, and the first metal layer is patterned by a mask process to form the gate lines 410 and the gate electrode 431.

Thereafter, a gate insulating layer 435 covering the gate lines 410 and the gate electrode 431 is formed by a vacuum deposition process.

Thereafter, a silicon layer is formed on the gate insulating layer 435, and is patterned to form the semiconductor layer 432.

Subsequently, a second metal layer is formed on the gate insulating layer 435 by a process such as vacuum deposition, and patterned to form the data wires 420, the source electrode 433, and the drain electrode 434. do.

Thereafter, the protective film 436 is formed by a spin coating process, and the contact hole is formed by a patterning process.

Thereafter, a third metal layer is formed on the passivation layer 436 by a process such as vacuum deposition, and patterned to form the pixel electrodes 440.

8 and 9, the sacrificial substrate 100 is etched to form a sacrificial frame 101.

In this case, an etching mask 500 is formed to etch the center portion CR of the sacrificial substrate 100. That is, the region CR in which the wiring units 400 are disposed in the sacrificial substrate 100 is selectively etched.

The etching mask 500 covers an outer area OR of the lower surface of the sacrificial substrate 100, covers a side surface of the sacrificial substrate 100, the wiring parts 400, the buffer layer 300, and the flexible layer. Cover the substrate 200.

Therefore, the etching mask 500 may effectively prevent the etching solution to be injected thereafter from penetrating the wiring units 400.

The etching mask 500 protects the wiring unit 400, the buffer layer 300, and the flexible substrate 200 from an etching solution. Examples of the material used for the etching mask 500 may include a resin such as an acrylic resin or a urethane resin.

Subsequently, an etchant is sprayed onto the lower surface of the sacrificial substrate 100, and a portion of the sacrificial substrate 100 is etched. In this case, the lower surface of the flexible substrate 200 is etched to expose the remaining portion of the sacrificial substrate 100 without being etched becomes the sacrificial frame 101.

Examples of the etchant include hydrofluoric acid or sulfuric acid reacting with glass and the like, and other examples include acids reacting with stainless steel.

The sacrificial substrate 100 may be etched by a dipping process or a spray process. That is, the sacrificial substrate 100 on which the etching mask 500 is disposed may be dipped in the etching liquid or the etching liquid may be injected to expose the lower surface of the flexible substrate 200 to expose the lower surface of the flexible substrate 200. .

Referring to FIG. 10, a support substrate 600 is attached to a lower surface of the exposed flexible substrate 200. The support substrate 600 is laminated on the bottom surface of the flexible substrate 200.

The support substrate 600 is flexible, but less flexible than the flexible substrate 200. Therefore, the support substrate 600 supports the flexible substrate 200. That is, the phenomenon in which the flexible substrate 200 is dried by the support substrate 600 is prevented.

Examples of the material used as the support substrate 600 may include plastic, thin metal or paper. That is, the support substrate 600 may be a plastic substrate, a thin metal substrate, or a paper substrate. The support substrate 600 may have a thickness of about 0.1 mm to about 5 mm.

Referring to FIG. 11, the support substrate 600 and the flexible substrate 200 are cut so that each wiring unit 400 is divided. Thereafter, an electrophoretic film is attached to the wiring parts 400, and a tape automated bonding (TAB) tape is attached to the gate pads 411 and the data pads 421.

As such, a plurality of electrophoretic display devices may be manufactured.

The electrophoretic film 700 includes a capsule including charged pigment particles and upper and lower protective layers positioned above and below the capsule.

The capsule comprises black dye particles responsive to a positive voltage, white dye particles responsive to a negative voltage, and solvent.

The upper and lower protective layers block the flow of spherical capsules and serve to protect the capsules. As the upper and lower protective layers, a flexible plastic, an easily bent base film, or a flexible metal may be used.

In addition, a color filter layer and a common electrode layer may be disposed on the electrophoretic film. In addition, an upper plate may be disposed on the common electrode layer.

The color filter layer includes a plurality of color filters. For example, the color filter layer may include a red color filter converting white light into red light, a green color filter converting white light into green light, and a blue color filter converting white light into blue light.

The common electrode forms a vertical electric field with the pixel electrode. The common electrode is transparent and made of a conductor. Examples of the material used as the common electrode include indium tin oxide (ITO) or indium zinc oxide (IZO).

The top plate is made of flexible plastic, easily bent base film, flexible metal, or the like. The upper plate is transparent and protects the common electrode and the color filter layer.

When a voltage having a positive polarity is applied to the pixel electrode and a voltage having a negative polarity is applied to the common electrode, the black dye particles face the pixel electrode, and the white dye particles are the common electrode. Heads up.

Thus, the electrophoretic film 700 implements a white mode.

When the voltage of negative polarity is applied to the pixel electrode and the voltage of positive polarity is applied to the common electrode, the black dye particles face the common electrode, and the white dye particles are the pixel electrode. Heads up.

Thus, the electrophoretic film 700 implements a black mode.

Since the sacrificial substrate 100 is etched by the etchant, the sacrificial substrate 100 is uniformly etched. Accordingly, the bottom surface of the flexible substrate 200 is smoothly exposed. More specifically, the lower surface of the flexible substrate 200 is smoother when the sacrificial substrate 100 is etched according to the present manufacturing method as compared with the case where the sacrificial substrate 100 is etched by a laser.

That is, when the sacrificial substrate 100 is released by the laser, residues may remain on the bottom surface of the flexible substrate 200 due to unevenness of the output of the laser. In addition, damage to the flexible substrate 200, the wiring part 400, or the tape may be caused by an undesirably strong laser.

In addition, when the sacrificial substrate 100 is released by the laser, a lot of time and cost are consumed to release the entire sacrificial substrate 100.

On the contrary, the manufacturing method can efficiently control the etching of the sacrificial substrate 100, and can realize low cost and high productivity by a dipping process or a spray process.

In addition, the etching mask 500 and the buffer layer 300 effectively prevent the etching solution from penetrating into the wiring unit 400. Therefore, the manufacturing method of the electrophoretic device display apparatus according to the present embodiment can reduce the defect.

Although the above description has been made based on the embodiments, these are merely examples and are not intended to limit the present invention. Those skilled in the art to which the present invention pertains may not have been exemplified above without departing from the essential characteristics of the present embodiments. It will be appreciated that many variations and applications are possible. For example, each component specifically shown in the embodiment can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

1 to 11 illustrate a process according to a method of manufacturing an electrophoretic display according to an exemplary embodiment.

6 is a circuit diagram showing respective wiring portions;

7 is a cross-sectional view showing in detail a thin film transistor.

Claims (10)

Attaching a flexible substrate on the sacrificial substrate; Forming a wiring part on the flexible substrate; And And etching the sacrificial substrate using an etchant. The method of claim 1, further comprising attaching a support substrate under the flexible substrate after the sacrificial substrate is etched. The method of claim 1, wherein the support substrate comprises plastic, metal, or paper. The method of claim 1, wherein etching the sacrificial substrate is performed. Etching a portion of the sacrificial substrate to form a sacrificial frame surrounding the wiring portion. The method of claim 1, wherein the sacrificial substrate is rigid and comprises glass or stainless steel. The method of claim 1, further comprising attaching an electrophoretic film on the wiring part. The method of claim 1, further comprising forming a buffer layer between the flexible substrate and the wiring unit. The method of claim 7, wherein the buffer layer comprises silicon nitride. Forming a flexible substrate on the sacrificial substrate; Forming a buffer layer on the flexible substrate; Forming a plurality of wiring units on the buffer layer; Etching a portion of the sacrificial substrate corresponding to the wiring portions using an etchant to form a sacrificial frame surrounding the wiring portions; And And attaching a support substrate under the flexible substrate to the inside of the sacrificial frame. The method of claim 9, wherein the wiring portion A plurality of gate lines extending parallel to each other in one direction; A plurality of data wires crossing the gate wires and extending in parallel with each other; A plurality of thin film transistors disposed in an area where the gate lines and the data lines cross each other; And And a plurality of pixel electrodes respectively disposed in the plurality of pixel regions defined by the gate lines and the data lines.

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