KR20080068348A - Method of manufacturing display device - Google Patents

Abstract

A method for manufacturing an LCD(Liquid Crystal Display) is provided to improve the electrical characteristics and reliability of a flexible display device by preventing multilayered thin films from being misaligned according to the retraction of an existing plastic substrate. A sacrifice pattern is formed on an auxiliary substrate. In this case, a sacrifice layer is first formed on the auxiliary substrate. Then the peripheral area of the auxiliary substrate is exposed through photolithography for the sacrifice layer. A reserve flexible substrate is formed on the auxiliary substrate and the sacrifice pattern. A certain thin film structure is formed on the reserve flexible substrate. A passivation film is formed on the thin film structure. Holes to expose the sacrifice pattern are formed at the reserve flexible substrate. The sacrifice pattern is etched through the exposed holes. The passivation film is removed. The reserve flexible substrate is separated from the auxiliary substrate.

Description

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

1 is a perspective view of an electrophoretic display device according to an exemplary embodiment of the present invention;

2 is a layout view of a thin film transistor array panel and a common electrode panel for an electrophoretic display device according to an exemplary embodiment of the present invention.

FIG. 3 is a cross-sectional view taken along line III-III ′ of the electrophoretic display device including the thin film transistor array panel and the common electrode display panel illustrated in FIG. 2;

FIG. 4 is a cross-sectional view of the electrophoretic display device including the thin film transistor array panel and the common electrode display panel illustrated in FIG. 2 taken along line IV-IV ′ of FIG. 2.

5 is a perspective view of a thin film transistor array panel at an intermediate stage of manufacturing the thin film transistor array panel for the electrophoretic display device illustrated in FIG. 1 according to an embodiment of the present invention;

FIG. 6 is a perspective view of a thin film transistor array panel in the next step of FIG. 5;

FIG. 7 is a perspective view of a thin film transistor array panel in the next step of FIG. 6;

FIG. 8 is a cross-sectional view of the thin film transistor array panel of FIG. 7 taken along the line VIII-VIII ′,

FIG. 9 is a layout view of a thin film transistor array panel at an intermediate stage of manufacturing the thin film transistor array panel illustrated in FIG. 2 according to an embodiment of the present disclosure;

FIG. 10 is a cross-sectional view of the thin film transistor array panel of FIG. 9 taken along the line X-X '.

FIG. 11 is a cross-sectional view of the thin film transistor array panel of FIG. 8 taken along the line XI-XI ′. FIG.

12 is a layout view of a thin film transistor array panel in the next step of FIG. 8;

FIG. 13 is a cross-sectional view of the thin film transistor array panel of FIG. 12 taken along the line XIII-XIII ′,

FIG. 14 is a cross-sectional view of the thin film transistor array panel of FIG. 12 taken along the line XIV-XIV ′.

FIG. 15 is a layout view of a thin film transistor array panel in the next step of FIG. 12;

FIG. 16 is a cross-sectional view of the thin film transistor array panel of FIG. 15 taken along the line XVI-XVI ′.

FIG. 17 is a cross-sectional view of the thin film transistor array panel of FIG. 15 taken along the line XVII-XVII ′,

FIG. 18 is a perspective view of a thin film transistor array panel in the next step of FIG. 7;

19 is a cross-sectional view of the thin film transistor array panel of FIG. 18 taken along the line XIX-XIX ',

20 is a cross-sectional view of the TFT panel in the next step of FIG. 18;

FIG. 21 is a cross-sectional view of the thin film transistor array panel of FIG. 20 taken along the line XXI-XXI ′,

FIG. 22 is a cross-sectional view of the common electrode panel at an intermediate stage of manufacturing the common electrode panel shown in FIG. 3 according to an embodiment of the present invention;

FIG. 23 is a cross-sectional view of the common electrode display panel in the next step of FIG. 22.

FIG. 24 is a cross-sectional view of the common electrode display panel in the next step of FIG. 23.

25 is a perspective view illustrating a bonded thin film transistor mother substrate and a common electrode mother substrate.

<Explanation of symbols for the main parts of the drawings>

100: thin film transistor display panel

110: insulating substrate 121: gate line

124: gate electrode 129: end of gate line

140: gate insulating film 151: linear semiconductor layer

161: linear ohmic contact 171: data line

173: source electrode 175: drain electrode

179: end of the data line 180: protective film

181, 182, and 185: contact hole 191: pixel electrode

200: common electrode display panel 210: insulating substrate

220: light blocking member 270: common electrode

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a liquid crystal display, and more particularly, to a method of manufacturing a flexible display device.

As the Internet becomes more popular and the amount of information communicated explosively, the future will create an environment of 'ubiquitous display' where people can access information anytime and anywhere. And the role of portable displays such as PDAs have become important. In order to implement such a ubiquitous display environment, the portability of the display is required to directly access information at a desired time and place, and a large screen characteristic for displaying various multimedia information is required. Accordingly, in order to simultaneously satisfy such portability and large screen characteristics, there is a need to develop a display in a form that can be expanded and used when functioning as a display by giving flexibility to the display and folded and stored when carrying.

In general, a flat panel display device replaces a conventional CRT and is a flat panel display device such as an organic light emitting diode display (OLED) and an electrophoretic display (EPD). Is used a lot.

By the way, since such a flat panel display uses a heavy and fragile glass substrate, there exists a limit in portability and a big screen display.

Therefore, in recent years, flat panel displays using lightweight plastic substrates that are not only light in weight and impact resistant but also have been developed.

In the case of using a flexible plastic substrate instead of the conventional glass substrate, it may have many advantages over the conventional glass substrate in terms of portability, safety, and light weight.

 In addition, in terms of process, the plastic substrate can be manufactured by deposition or printing, thereby lowering the manufacturing cost, and, unlike the conventional sheet-based process, a roll-to-roll process Since the display device can be manufactured, a low cost display device can be manufactured through mass production.

However, since the plastic substrate may be shrunk by the process temperature, there is a difficulty in proceeding the process at a low temperature.

In order to prevent shrinkage of the plastic, a plastic substrate is attached to the auxiliary substrate with an adhesive, and then a flexible resin is formed by forming a thin film structure on the plastic substrate or by using a spin coating method on the auxiliary substrate. After coating, a plastic substrate is formed and a thin film structure is formed thereon to form a thin film transistor array panel. Subsequently, the auxiliary substrate and the plastic substrate are separated by a laser process or a chemical process in a subsequent process, and the separation process of the auxiliary substrate and the plastic substrate is easy as the adhesive and the plastic substrate are deformed by the thermal process. There is a process difficulty that is not.

In addition, due to the characteristics of the plastic, the alignment and holes between the thin films may be misaligned, and thus the electrical characteristics and the reliability of the display device may be degraded.

Accordingly, an object of the present invention is to prevent misalignment of the layer arrangement as the plastic substrate of the flexible display device shrinks, thereby improving electrical characteristics and reliability of the flexible display device.

According to an exemplary embodiment of the present invention, a display device may include forming a sacrificial pattern on an auxiliary substrate, forming a preliminary flexible substrate on the auxiliary substrate and the sacrificial pattern, and forming a predetermined thin film structure on the preliminary flexible substrate. Forming a protective film over the structure, forming a hole exposing the sacrificial pattern on the preliminary flexible substrate, etching the sacrificial pattern through the exposed hole, removing the protective film, the preliminary availability Separating the substrate from the auxiliary substrate.

The forming of the sacrificial pattern may include forming a sacrificial layer on the auxiliary substrate and exposing a peripheral region of the auxiliary substrate by photolithography the sacrificial layer.

The sacrificial pattern may be formed of a transparent conductive film such as ITO, IZO, or a-ITO, and the sacrificial pattern may have a thickness of about 100 μs to about 1,000 μs.

The preliminary flexible substrate may have a thickness of about 10 μm to about 200 μm, and the protective layer may be formed of a photosensitive material.

Forming a plurality of thin films on the preliminary flexible substrate may include forming a first signal line on the preliminary flexible substrate, forming a second signal line crossing the first signal line, and having first to third terminals. And forming a switching device having a first terminal and a second terminal connected to the first signal line and the second signal line, respectively, and forming a pixel electrode connected to a third terminal of the switching device. can do.

The forming of the plurality of thin films on the preliminary flexible substrate may include forming a plurality of light blocking members on the preliminary flexible substrate, between the adjacent light blocking members, and corresponding to the pixel electrodes of the preliminary flexible substrate. Forming a color filter at a position, forming an overcoat on the light blocking member and the color filter, and forming a common electrode on the overcoat.

The preliminary flexible substrate may be made of polyimide or polyester sulfone (PES).

The hole exposing the sacrificial pattern may be formed by irradiating a laser with a predetermined angle.

The method may further include cutting a portion around the portion including the predetermined thin film structure of the preliminary flexible substrate and separating it from the remaining portion before separating the preliminary soluble substrate from the auxiliary substrate.

 Peripheral incision of the portion including the predetermined thin film structure of the preliminary flexible substrate may be performed by irradiating a laser in a direction perpendicular to the auxiliary substrate on an area surrounding the predetermined thin film.

The etching of the sacrificial pattern may be performed by immersing the auxiliary substrate in a bath containing an etchant.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. When a part of a layer, film, area, plate, etc. is said to be "on" another part, this includes not only the other part "directly" but also another part in the middle. On the contrary, when a part is “just above” another part, there is no other part in the middle.

Hereinafter, a case in which the present invention is applied to manufacturing an electrophoretic display device will be described.

Next, an electrophoretic display device and a manufacturing method thereof according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

First, an electrophoretic display device according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4.

1 is a perspective view of an electrophoretic display device according to an embodiment of the present invention, FIG. 2 is a layout view of a thin film transistor array panel and a common electrode display panel for an electrophoretic display device according to an embodiment of the present invention, and FIG. An electrophoretic display device including the thin film transistor array panel and the common electrode display panel illustrated in FIG. 2 is a cross-sectional view taken along the line III-III ′ of FIG. 2, and FIG. 4 includes the thin film transistor array panel and the common electrode display panel illustrated in FIG. 2. Is a cross-sectional view taken along line IV-IV 'of FIG. 2.

1 to 4, the electrophoretic display device according to the present exemplary embodiment includes a thin film transistor array panel 100 including a thin film structure, a common electrode display panel 200, and an electrophoretic film 300 interposed therebetween. Include.

Here, the region in which the common electrode display panel 200 and the thin film transistor array panel 100 face each other is the display area DA, and the plurality of gate lines 121 and the data lines 171 are arranged in a substantially matrix form. The area excluding the display area DA is a peripheral area PA, and a drive integrate circuit is formed.

Next, the thin film transistor array panel 100 will be described.

As shown in FIGS. 1 to 4, the thin film transistor array panel 100 is made of polyimide or polyester sulfone (PES) having excellent heat resistance and having less bending and shrinkage than plastic. A plurality of gate lines 121 and a plurality of storage electrode lines 131 are formed on the substrate 110 and include the insulating substrate 110. Here, the insulating substrate 110 has a thickness of 10 μm to 200 μm, and the gate line 121 has a plurality of gate electrodes 124 and a wide end portion 129 for connection with another layer or an external circuit. ).

The gate line 121 transmits a gate signal and mainly extends in a horizontal direction. Each gate line 121 includes a plurality of gate electrodes 124 protruding downward and an end portion 129 having a large area for connection with another layer or an external driving circuit. A gate driving circuit (not shown) for generating a gate signal is mounted on a flexible printed circuit film (not shown) attached to the substrate 110 or directly mounted on the lower plastic substrate 110. Or may be integrated into the substrate 110. When the gate driving circuit is integrated on the substrate 110, the gate line 121 may extend to be directly connected to the gate driving circuit.

The storage electrode line 131 receives a predetermined voltage, and includes a stem line extending substantially in parallel with the gate line 121 and a plurality of pairs of storage electrodes 133a and 133b separated therefrom. Each of the storage electrode lines 131 is positioned between two adjacent gate lines 121, and the stem line is closer to the lower side of the two gate lines 121. Each of the sustain electrodes 133a and 133b has a fixed end connected to the stem line and a free end opposite thereto. The fixed end of one sustain electrode 133b has a large area, and its free end is divided into two parts, a straight part and a bent part. However, the shape and arrangement of the storage electrode line 131 may be modified in various ways.

The gate line 121 and the storage electrode line 131 may be formed of aluminum-based metal such as aluminum (Al) or aluminum alloy, silver-based metal such as silver (Ag) or silver alloy, copper-based metal such as copper (Cu) or copper alloy, or molybdenum ( It may be made of molybdenum-based metals such as Mo) or molybdenum alloy, chromium (Cr), tantalum (Ta) and titanium (Ti). However, they may have a multilayer structure including two conductive films (not shown) having different physical properties. One of the conductive films is made of a low resistivity metal such as an aluminum-based metal, a silver-based metal, or a copper-based metal to reduce signal delay or voltage drop. On the other hand, other conductive films are made of other materials, particularly materials having excellent physical, chemical and electrical contact properties with indium tin oxide (ITO) and indium zinc oxide (IZO), such as molybdenum-based metals, chromium, titanium, tantalum, and the like. Good examples of such a combination include a chromium bottom film, an aluminum (alloy) top film, and an aluminum (alloy) bottom film and a molybdenum (alloy) top film. However, the gate line 121 and the storage electrode line 131 may be made of various metals and conductors.

Side surfaces of the gate line 121 and the storage electrode line 131 are inclined with respect to the surface of the substrate 110, and the inclination angle is preferably about 30 ° to about 80 °.

A gate insulating layer 140 made of silicon nitride (SiNx) or silicon oxide (SiOx) is formed on the gate line 121 and the storage electrode line 131.

A plurality of linear semiconductors 151 made of polysilicon are formed on the gate insulating layer 140. The linear semiconductor 151 mainly extends in the longitudinal direction and includes a plurality of projections 154 extending toward the gate electrode 124.

Linear and island ohmic contacts 161 and 165 are sequentially formed on the semiconductor 151.

The ohmic contacts 161 and 165 may be made of a material such as amorphous silicon and polycrystalline silicon doped with a high concentration of n-type impurities such as phosphorus or p-type impurities such as boron (B), or may be made of silicide. . The linear ohmic contact 161 has a plurality of protrusions 163, and the protrusion 163 and the ohmic contact 165 are paired and disposed on the protrusion 154 of the semiconductor 151.

Side surfaces of the semiconductors 151 and 154 and the ohmic contacts 161 and 165 are also inclined with respect to the surface of the substrate 110, and the inclination angle is about 30 ° to 80 °.

A plurality of data lines 171 and a plurality of drain electrodes 175 are formed on the ohmic contacts 161 and 165 and the gate insulating layer 140.

The data line 171 transmits a data signal and mainly extends in the vertical direction to cross the gate line 121. Each data line 171 also crosses the storage electrode line 131 and is present between adjacent sets of storage electrodes 133a and 133b. Each data line 171 includes a plurality of source electrodes 173 extending toward the gate electrode 124 and an end portion 179 having a large area for connection with another layer or an external driving circuit. A data driving circuit (not shown) for generating a data signal is mounted on a flexible printed circuit film (not shown) attached to the substrate 110, directly mounted on the substrate 110, or integrated in the substrate 110. Can be. When the data driving circuit is integrated on the substrate 110, the data line 171 may be extended to be directly connected to the data driving circuit.

The drain electrode 175 is separated from the data line 171 and faces the source electrode 173 with respect to the gate electrode 124.

Each drain electrode 175 has one wide end portion and the other end having a rod shape, and the rod end portion is partially surrounded by the bent source electrode 173.

One gate electrode 124, one source electrode 173, and one drain electrode 175 together with the protrusion 154 of the semiconductor 151 form one thin film transistor (TFT). A channel of the transistor is formed in the protrusion 154 between the source electrode 173 and the drain electrode 175.

The data line 171 and the drain electrode 175 are preferably made of a refractory metal such as molybdenum, chromium, tantalum, titanium, or an alloy thereof, and a conductive film (not shown) such as a refractory metal and a low resistance material conductive film. It may have a multilayer film structure composed of (not shown). Examples of the multilayer film structure include a double film of chromium or molybdenum (alloy) lower film and an aluminum (alloy) upper film, a triple layer of molybdenum (alloy) lower film, aluminum (alloy) interlayer and molybdenum (alloy) upper film. However, the data conductors 171 and 175 may be made of various other metals or conductors.

The data conductors 171 and 175 may also be inclined at an inclined angle of about 30 ° to 80 ° with respect to the surface of the substrate 110.

The ohmic contacts 161 and 165 exist only between the semiconductor 151 below and the data line 171 and the drain electrode 175 thereon, and lower the contact resistance therebetween.

The semiconductor 151 has a portion exposed between the source electrode 173 and the drain electrode 175 and not covered by the data line 171 and the drain electrode 175.

On the data line 171, the drain electrode 175, and the exposed semiconductor 151, a passivation layer 180 made of an organic insulator having excellent planarization characteristics and photosensitivity is formed. Here, the organic insulator constituting the passivation layer 180 may have photosensitivity, and the dielectric constant thereof is preferably about 4.0 or less.

Meanwhile, the passivation layer 180 may be formed of an inorganic insulator such as silicon nitride (SiNx) and silicon oxide (SiOx), or may include a lower passivation layer made of an inorganic insulator and an upper passivation layer made of an organic insulator.

In the passivation layer 180, a plurality of contact holes 181, 182, and 185 exposing the end portion 179 and the drain electrode 175 of the data line 171 and the end portion of the gate line 121 ( A plurality of contact holes 181 exposing the 129, a plurality of contact holes 183a exposing a part of the sustain electrode line 131 near the fixed end of the sustain electrode 133b, and a straight portion of the free end of the sustain electrode 133a. A plurality of contact holes 183b are formed.

A plurality of pixel electrodes 191, a plurality of overpasses 83, and a plurality of contact assistants 81 and 82 are formed on the passivation layer 180. They may be made of a transparent conductive material such as ITO or IZO or a reflective metal such as aluminum, silver, chromium or an alloy thereof.

The pixel electrode 191 is physically and electrically connected to the drain electrode 175 through the contact hole 185 and receives a data voltage from the drain electrode 175.

The contact auxiliary members 81 and 82 are connected to the end portion 129 of the gate line 121 and the end portion 179 of the data line 171 through the contact holes 181 and 182, respectively. The contact auxiliary members 81 and 82 compensate for and protect the adhesion between the end portions 179 and 129 of the data line 171 and the gate line 121 and the external device.

The connecting leg 83 crosses the gate line 121 and exposes the exposed portion of the storage electrode line 131 and the storage electrode through contact holes 183a and 183b positioned on opposite sides with the gate line 121 interposed therebetween. 133b) is connected to the exposed end of the free end. The storage electrode lines 131 including the storage electrodes 133a and 133b may be used together with the connecting legs 83 to repair defects in the gate line 121, the data line 171, or the thin film transistor.

An electrophoretic film 300 is formed on the pixel electrode 191 and the passivation layer 180.

The electrophoretic film 300 includes an electrophoretic member 330 and a curing agent 310 for fixing the electrophoretic member 330 on the lower substrate 110.

Electrophoretic member 330 is dispersed and fixed in the electrophoretic film 300, electrophoretic particles (323, 326) and electrophoretic particles (323, 326) having a negative (+) charge and a positive (+) charge ) Is a dispersion medium 328 is dispersed, and the capsule (320) containing them (323, 326, 328). Here, the negatively charged electrophoretic particles 323 have a black color, and the positively-charged electrophoretic particles 326 have a white color. In the electrophoretic display device, the pixel electrode 191 to which the data voltage of the thin film transistor array panel 100 is applied generates an electric field together with the common electrode 270 of the common electrode display panel 200 to which a common voltage is applied. Create The generated electric field changes the positions of the electrophoretic particles 323 and 326 of the plurality of electrophoretic members 330 which are dispersed and fixed in the electrophoretic film 300, thereby displaying a desired image. Here, the electrophoretic particles 323 and 326 may display a black and white image. When the white electrophoretic particles 326 move in a direction in which the common electrode 270 is located, a white image is displayed and black electrophoresis is performed. When the particles 323 move in the direction in which the common electrode 270 is located, a black image is displayed.

Next, the common electrode display panel 200 will be described.

As shown in FIG. 3, the plurality of light blocking members 220 are disposed on a substrate 210 made of polyimide or polyester sulfone (PES) having excellent heat resistance and less bending and shrinkage than plastic. Is formed. Here, the insulating substrate 210 preferably has a thickness of 10 μm to 200 μm.

In addition, red, blue, and green color filters 230 are formed between the light blocking members 220 adjacent to each other.

Each color filter 230 overlaps the data line 171 of the thin film transistor array panel 110 and extends in the longitudinal direction. However, instead of the color filter 230 extending in the vertical direction, a rectangular color filter 230 may be formed in an area partitioned by the gate line 121 and the data line 171.

An overcoat 250 is formed on the color filter 230 and the light blocking member 220, and a surface thereof is flat. A common electrode 270 made of indium tin oxide (ITO) or indium zinc oxide (IZO) is formed on the overcoat 250.

In the present embodiment, although the color is implemented using the color filter as an example, the color may be implemented using the electrophoretic particles 323 and 326 having red, green, and blue colors.

Next, a method of manufacturing the thin film transistor array panel for the electrophoretic display device illustrated in FIGS. 1 to 4 will be described in detail with reference to FIGS. 5 to 21.

5 is a perspective view of a thin film transistor array panel at an intermediate stage of manufacturing the thin film transistor array panel for the electrophoretic display device shown in FIG. 1 according to an embodiment of the present invention, and FIG. FIG. 7 is a perspective view of the thin film transistor array panel of the next step of FIG. 6, FIG. 8 is a cross-sectional view of the thin film transistor array panel of FIG. 7 taken along the line VIII-VIII ′, and FIG. 9 is a view of FIG. FIG. 10 is a layout view of a thin film transistor array panel at an intermediate stage of manufacturing a thin film transistor array panel according to an exemplary embodiment of the present invention. FIG. 10 is a cross-sectional view of the thin film transistor array panel of FIG. 9 taken along a line XX ', and FIG. 11 is a cross-sectional view of the thin film transistor array panel of FIG. 8 taken along the line XI-XI ′, and FIG. 12 is a table of the thin film transistors in the next step of FIG. 8. FIG. 13 is a cross-sectional view of the thin film transistor array panel of FIG. 12 taken along the line XIII-XIII ', and FIG. 14 is a cross-sectional view of the thin film transistor array panel of FIG. 12 taken along the line XIV-XIV'. FIG. 15 is a layout view of a thin film transistor array panel in a next step of FIG. 12, and FIG. 16 is a cross-sectional view of the thin film transistor array panel of FIG. 15 taken along line XVI-XVI ′, and FIG. 17 is a view illustrating the thin film transistor array panel of FIG. 15. 18 is a cross-sectional view taken along the line XVII-XVII ', and FIG. 18 is a perspective view of the thin film transistor array panel in the next step of FIG. 7, and FIG. 19 is a cutaway view along the line XIX-XIX ′ of FIG. 18. 20 is a cross-sectional view of the thin film transistor array panel of the next step of FIG. 18, and FIG. 21 is a cross-sectional view of the thin film transistor array panel of FIG. 20 taken along the line XXI-XXI ′.

First, as shown in FIG. 5, a sacrificial layer 30 made of ITO, a-ITO, or IZO is formed on the lower auxiliary substrate 800 made of glass by using a sputtering process, and the sacrificial layer 30 is formed. The photosensitive film 10 is formed on an area except the outer portion of At this time, the sacrificial layer 30 is preferably formed to a thickness of about 100 kPa to 1,000 kPa.

6, the sacrificial layer 30 is etched using the photosensitive film 10 as a mask to form a lower sacrificial pattern 31. Therefore, the sacrificial layer 30 is not removed from the outer portion of the lower auxiliary substrate 800.

Next, as illustrated in FIGS. 7 and 8, a plurality of cell areas divided into a peripheral area PA and a display area DA on the lower auxiliary substrate 800 and the lower sacrificial pattern 31 are formed. A preliminary lower flexible substrate 51 having A, B, C, and D is formed. Each cell region includes a thin film transistor layer 400 which will be described later. Here, the preliminary lower flexible substrate 51 is made of polyimide or polyester sulfone (PES) having excellent heat resistance and less bending and shrinkage than plastic, and has a thickness of 10 μm to 200 μm. It is preferable. The preliminary lower flexible substrate 51 may have a step since the preliminary lower flexible substrate 51 is formed on a region where the lower sacrificial pattern 31 exists and a region where the lower sacrificial pattern 31 does not exist. In this case, the preliminary lower flexible substrates A and B corresponding to the cell region are positioned inside the outer portion of the lower sacrificial pattern 31.

Next, as shown in FIGS. 9 to 11, the metal film is sputtered on the preliminary lower flexible substrates A and B corresponding to each cell region of the preliminary lower flexible substrate 51, and then photo-etched. Thus, a plurality of gate lines 121 including the gate electrode 124 and the end portion 129 and a plurality of storage electrode lines 131 including the storage electrodes 133a and 133b are formed.

Next, the gate insulating layer 140 is formed on the gate line 121, the storage electrode line 131, and the preliminary lower flexible substrates A, B, C, and D corresponding to the cell region. In this case, the gate insulating layer 140 is made of silicon nitride (SiNx) or silicon oxide (SiOx).

Subsequently, an intrinsic amorphous silicon (a-Si) layer which is not doped with impurities and an amorphous silicon (n + a-Si) layer which is doped with impurities are formed by a plasma enhanced chemical vapor deposition (PECVD) method. A data layer made of metal such as molybdenum is formed on the doped amorphous silicon layer.

Then, the data layer, an amorphous silicon layer doped with impurities, and an intrinsic amorphous silicon layer are sequentially etched using a mask to form the data line 171 including the source electrode 173, the drain electrode 175, and the ohmic contact member ( 161 and the semiconductor 151 are formed.

12 to 14, a passivation layer 180 is formed on the gate insulating layer 140, the data line 171, and the drain electrode 175. In this case, the passivation layer 180 is made of an organic insulator. Here, the organic insulator may have photosensitivity and the dielectric constant thereof is preferably about 4.0 or less.

However, the passivation layer 180 may include a lower passivation layer made of an inorganic insulator such as silicon nitride (SiNx) and silicon oxide (SiOx), and an upper passivation layer made of an organic insulator, or may be made of only an inorganic insulator.

Next, the passivation layer 180 is etched to remove the end portion 129 of the gate line 121, the end portion 179 of the data line 171, and a part of the storage electrode line 131 near the fixed end of the storage electrode 133b. A plurality of exposed contact holes 183a, a plurality of contact holes 183b exposing a straight portion of the free end of the sustain electrode 133a, and contact holes 181, 182, 183a, 183b, and 185 exposing the drain electrode 175; To form.

Next, as shown in FIGS. 15 to 17, transparent electrodes such as ITO or IZO are sputtered on the contact holes 181, 182, 183a, 183b, and 185 and the passivation layer 180. The pixel electrode 191, the connection legs 83, and the contact members 81 and 82 are formed.

As such, one gate electrode 124, one source electrode 173, and one drain electrode 175 form one thin film transistor (TFT) together with the semiconductor 151, and the source electrode 173. ) And a channel is formed in the semiconductor 151 existing between the drain electrode and the drain electrode 175. The thin film transistor controls the data signal transmitted to the pixel electrode 191 through the data line 171 according to the gate signal transmitted through the gate line 121.

Heat is generated in the step of manufacturing such a thin film transistor, wherein the generated heat is insufficient to shrink or bend the preliminary lower flexible substrate 51 made of polyimide or polyester sulfone having a low coefficient of thermal expansion. As such, since the preliminary lower flexible substrate 51 is not shrunk or bent by heat generated when the thin film transistor is manufactured, the electrical characteristics and the reliability of the thin film transistor may be improved.

Thereafter, in the present specification, a thin film structure including a thin film transistor is defined as a thin film transistor layer 400.

18 and 19, a lower photosensitive protective layer 80 is formed by coating a photosensitive material on the thin film transistor layer 400 including the thin film transistor. Here, the lower photosensitive protective film 80 preferably has a thickness of 1 μm or more. The laser is positioned on the lower photosensitive protection layer 80 to surround four sides of the lower sacrificial pattern 31 and does not overlap the cell regions A, B, C, and D of the preliminary lower flexible substrate 51. ) Is formed to form a plurality of holes 101, 102, 103, 104, 105, 106. Here, the holes 101, 102, 103, 104, 105, and 106 expose the lower sacrificial pattern 31 made of a transparent conductive film.

Then, the lower auxiliary substrate 800 having the predetermined structure is immersed in a bath containing an etchant for removing the lower sacrificial pattern 31. At this time, the etchant penetrates into the lower sacrificial pattern 31 through the holes 101, 102, 104, and 105 to remove the lower sacrificial pattern 31. As a result, the area where the lower sacrificial pattern 31 was provided becomes the empty space 40. The lower photosensitive protective layer 80 prevents the pixel electrode 191, the connection legs 83, and the contact members 81 and 82 of the thin film transistor layer 400 from being removed by the transparent conductive layer etchant.

Next, as shown in FIGS. 20 and 21, the lower photosensitive protective film 80 is removed. The cell regions A, B, C, and D are closer to the cell regions A, B, C, and D than the holes 101 and 104, and the cell regions A, B, C, and D do not face each other. A laser beam is irradiated to the space surrounding the side of D) to form a rectangular frame-shaped hole 71. Here, the hole 71 has a rectangular frame shape and exposes the empty space 40. In this way, the hole 71 and the empty space 40 are connected, and a part of the preliminary lower flexible substrate 51 is separated from the auxiliary substrate 800 to form the thin film transistor mother substrate 750.

Conventionally, a plastic substrate is bonded to an auxiliary substrate with an adhesive, and then a thin film structure is formed on the plastic substrate or a flexible synthetic resin is applied to the auxiliary substrate by using a spin coating method to form a flexible mother substrate. Then, a thin film structure was formed on the thin film transistor mother substrate, which was heated and separated from the auxiliary substrate by applying a physical force. In this process, the plastic substrate bends or shrinks due to thermal and physical forces. As a result, a problem arises in that the thin film array and the holes are misaligned, thereby deteriorating the electrical characteristics and the reliability of the electrophoretic display device.

However, in the present invention, the lower sacrificial pattern 31 is removed by penetrating the etching solution into the lower sacrificial pattern 31 through the holes 101, 102, 103, 104, 105, and 106 exposing the lower sacrificial pattern 31. An empty space 40 is formed, and the lower auxiliary substrate 800 and the preliminary lower flexible substrate 51 are separated by forming a hole 71 perpendicular to the empty space 40 and connected to the empty space 40. Therefore, it is not necessary to proceed with the thermal process for separating the plastic substrate, which is conventionally glued on the auxiliary substrate. Accordingly, misalignment of the thin film transistors due to shrinkage characteristics of the plastic substrate may be prevented, thereby improving electrical characteristics and reliability of the flexible electrophoretic display device.

Next, a method of manufacturing the common electrode display panel for the electrophoretic display device illustrated in FIGS. 1 to 4 according to an embodiment of the present invention will be described in detail with reference to FIGS. 22 to 24.

FIG. 22 is a cross-sectional view of the common electrode display panel in an intermediate step of manufacturing the common electrode display panel shown in FIG. 3 according to an embodiment of the present invention, FIG. 23 is a cross-sectional view of the common electrode display panel in the next step of FIG. FIG. 24 is a cross-sectional view of the common electrode display panel of the next step of FIG. 23, and FIG. 25 is a perspective view of the bonded thin film transistor mother substrate and the common electrode mother substrate.

First, as shown in FIG. 22, an upper sacrificial pattern 32 made of a transparent conductive film such as ITO, a-ITO, or IZO is formed on the upper auxiliary substrate 802 made of glass. In this case, the upper sacrificial pattern 32 has a thickness of about 100 kPa to about 1,000 kPa, and is not present at the outer portion of the upper auxiliary substrate 802.

Next, a preliminary upper flexible substrate 52 having a plurality of cell regions is formed on the upper auxiliary substrate 802 and the upper sacrificial pattern 32. Here, the preliminary upper flexible substrate 52 is made of polyimid or polyester sulfone (PES) having excellent heat resistance and less bending and shrinkage than plastic, and has a thickness of 10 μm to 200 μm. It is preferable.

Next, an opaque metal such as chromium (Cr) is deposited on the preliminary upper flexible substrate 51 region corresponding to the display area DA of the thin film transistor mother substrate 750 and photo-etched to form the light blocking member 220. do. Next, the red color filter 230 is formed by applying, exposing and developing a photosensitive agent including a red pigment. A photosensitive agent including a green pigment and a photosensitive agent including a blue pigment are also coated and exposed to develop a green color filter 230 and a blue color filter 230. The order of forming the red, green, and blue color filters 230 may be different. Subsequently, an organic insulating material is coated on the color filter 230 to form an over coat layer 250.

Next, as illustrated in FIG. 23, a transparent conductive material is deposited on the overcoat 250 to form a common electrode 270.

In the manufacturing of the light blocking member 220, the color filter 230, and the common electrode 270, heat is generated, wherein the generated heat is a preliminary upper flexible substrate made of polyimide or polyester sulfone having a low coefficient of thermal expansion. (52) is not sufficient to shrink or bend. As such, the preliminary upper flexible substrate 52 is not contracted or bent due to heat generated when the thin film structures such as the light blocking member 220, the color filter 230, and the common electrode 270 are formed. Characteristics and reliability can be improved.

Then, an upper photosensitive protective layer 82 is formed on the common electrode 270 and the preliminary upper flexible substrate 52. In addition, a plurality of the upper sacrificial patterns 32 are exposed to the periphery of the thin film structure such as the light blocking member 220, the color filter 230, and the common electrode 270 by irradiating a laser on the upper photosensitive protective layer 82 at a predetermined angle. Holes 201, 202, 203, 204, 205 and 206 are formed.

Then, the upper auxiliary substrate 802 having such a predetermined structure is immersed in a bath containing an etchant for removing the transparent conductive film. At this time, the etchant penetrates into the upper sacrificial pattern 32 through the holes 201, 202, 204, and 205 to remove the upper sacrificial pattern 32. As a result, the area where the upper sacrificial pattern 32 was located becomes the empty space 90. Here, the upper photosensitive protective layer 82 prevents the common electrode 270 from being removed by the transparent conductive layer etchant.

Next, as shown in FIG. 24, the upper photosensitive protective film 82 is removed. The hole 72 is formed by irradiating a laser in a direction perpendicular to the upper auxiliary substrate 802 to surround the thin film structure and overlap the empty space 90. At this time, the hole 72 has a rectangular frame structure, and exposes the empty space 90. As such, as the hole 72 and the empty space 90 are connected to form one passage, a part of the preliminary upper flexible substrate 52 is separated to become the common electrode mother substrate 760.

As described above, in the present invention, the etching solution penetrates into the upper sacrificial pattern 32 through the holes 201, 202, 203, 204 205, and 206, thereby removing the upper sacrificial pattern 32, thereby creating an empty space 90. It is perpendicular to the void 90 and forms a hole 72 connected to the void 90 to separate the upper auxiliary substrate 800 and the preliminary upper flexible substrate 52, which is conventionally used as an adhesive on the auxiliary substrate. There is no need to proceed with the thermal process to separate the attached plastic substrate. Accordingly, misalignment of the thin film transistors due to shrinkage characteristics of the plastic substrate may be prevented, thereby improving electrical characteristics and reliability of the flexible electrophoretic display device.

Next, as shown in FIG. 25, an electrophoretic film 300 is formed on the thin film transistor layer 400 of the thin film transistor mother substrate 750, and the thin film transistor mother substrate 750 and the common electrode mother substrate ( 760). In this case, the cell area of the common electrode mother substrate 760 faces the thin film transistor layer 400 formed on the thin film transistor mother substrate 750.

Next, the thin film transistor mother substrate 750 and the common electrode mother substrate 760 are cut along the cell scribe line 801. In this case, the bonded thin film transistor mother substrate 750 and the common electrode mother substrate 760 are separated into the common electrode display panel 200 and the thin film transistor array panel 100, as shown in FIG. 1.

The electrophoretic film 300 includes an electrophoretic member 330 and a curing agent 310 for fixing the electrophoretic member 330 on the lower substrate 110.

Electrophoretic member 330 is dispersed and fixed in the electrophoretic film 300, electrophoretic particles (323, 326) and electrophoretic particles (323, 326) having a negative (+) charge and a positive (+) charge ) Is a dispersion medium 328 is dispersed, and the capsule (320) containing them (323, 326, 328). Here, the negatively charged electrophoretic particles 323 have a black color, and the positively-charged electrophoretic particles 326 have a white color. However, the electrophoretic particles 323 and 326 may have colors such as red, blue, and green.

In the present specification, the electrophoretic display device is described as an example, but after forming a flexible substrate layer such as polyimide on the sacrificial layer formed on the auxiliary substrate, and forming a required thin film structure on the flexible substrate layer, the sacrificial layer The method of the present invention which removes and cuts the flexible substrate layer to form the necessary thin film substrate can also be applied to manufacturing a display device such as an organic light emitting display (OLED) or a liquid crystal display (LCD).

In the present invention, a sacrificial pattern is formed on an auxiliary substrate made of glass, and a preliminary flexible substrate made of polyimide or polyester sulfone having a low coefficient of thermal expansion is formed on the sacrificial pattern and the auxiliary substrate, and a thin film structure is formed thereon. A photosensitive protective film is formed to cover and protect the structure. The laser is irradiated at a predetermined angle to form contact holes exposing the four sides of the sacrificial pattern, and the auxiliary substrate is placed in a bath containing the etchant to infiltrate the etchant into the sacrificial pattern through the hole. Remove to make a space. Next, the mother substrate is overlapped with an outer portion of the empty space, and the mother substrate is formed by separating the auxiliary substrate and the preliminary flexible substrate by irradiating a laser to the region surrounding the thin film structure in a direction perpendicular to the auxiliary substrate. As a result, misalignment of the thin film of the multilayer structure due to the shrinkage characteristic of the conventional plastic substrate may be prevented, thereby improving electrical characteristics and reliability of the flexible display device.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (13)

Forming a sacrificial pattern on the auxiliary substrate, Forming a preliminary flexible substrate on the auxiliary substrate and the sacrificial pattern; Forming a predetermined thin film structure on the preliminary flexible substrate, Forming a protective film on the thin film structure; Forming a hole exposing the sacrificial pattern on the preliminary flexible substrate, Etching the sacrificial pattern through the exposed holes; Removing the protective film, Separating the preliminary soluble substrate from the auxiliary substrate, Method of manufacturing a display device comprising a. In claim 1, Forming the sacrificial pattern is Forming a sacrificial layer on the auxiliary substrate; Photo-etching the sacrificial layer to expose a peripheral region of the auxiliary substrate Method of manufacturing a display device comprising a. In claim 1, The sacrificial pattern may be formed of a transparent conductive film such as ITO, IZO, or a-ITO. In claim 3, The sacrificial pattern has a thickness of about 100 GPa to 1,000 GPa. In claim 1, The preliminary flexible substrate has a thickness of about 10 μm to about 200 μm. In claim 1, The passivation layer is made of a photosensitive material. In claim 1, Forming a plurality of thin films on the preliminary flexible substrate Forming a first signal line on the preliminary flexible substrate, Forming a second signal line crossing the first signal line; Forming a switching element having first to third terminals and having a first terminal and a second terminal connected to the first signal line and the second signal line, respectively; and Forming a pixel electrode connected to the third terminal of the switching element Method of manufacturing a display device comprising a. In claim 1, Forming a plurality of thin films on the preliminary flexible substrate Forming a plurality of light blocking members on the preliminary flexible substrate, Forming a color filter between the adjacent light blocking members and corresponding to the pixel electrode of the preliminary flexible substrate; Forming an overcoat on the light blocking member and the color filter, and Forming a common electrode on the overcoat Method of manufacturing a display device comprising a. In claim 1, The preliminary flexible substrate is made of polyimide or polyester sulfone (PES). In claim 1, The hole for exposing the sacrificial pattern is formed by irradiating a laser. In claim 1, And cutting a portion around the portion including the predetermined thin film structure of the preliminary flexible substrate from the remaining portion before separating the preliminary soluble substrate from the auxiliary substrate. In claim 11,  Peripheral cutting of the portion of the preliminary flexible substrate including the predetermined thin film structure is performed by irradiating a laser in a direction perpendicular to the auxiliary substrate on a region surrounding the predetermined thin film. In claim 1, The etching of the sacrificial pattern is performed by immersing the auxiliary substrate in a bath containing an etchant.

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