KR20200032680A - Display panel and method of manufacturing the same - Google Patents

Abstract

A display panel comprises: a first switching element; a first pixel electrode electrically connected to the first switching element, and including a material having reflectivity; a first emission layer disposed on the first pixel electrode, and emitting light of a first color when a voltage is applied to the first pixel electrode; a thin protective film disposed on the first emission layer to protect the first emission layer; a pressure sensitive adhesive layer disposed on the thin protective film; and a first color filter disposed on the pressure sensitive adhesive layer, and corresponding to the first emission layer and having the first color.

Description

DISPLAY PANEL AND METHOD OF MANUFACTURING THE SAME

The present invention relates to a display panel and a method for manufacturing the display panel, and more particularly, to a display panel for an organic light emitting display device and a method for manufacturing the display panel.

In recent years, thanks to advances in technology, display products having higher performance while being smaller and lighter have been produced. Conventional cathode ray tube (CRT) has been widely used in display devices with many advantages in terms of performance and price, but overcomes the shortcomings of CRT in terms of miniaturization or portability, miniaturization, light weight, and low power consumption. Background Art An organic light emitting display device having advantages has attracted attention.

The organic light emitting display device may express various colors, including organic light emitting layers and pixel electrodes that emit red, green, and blue colors. The pixel electrode of the organic light emitting display device reflects light with a reflective electrode, and there is a problem in that visibility is deteriorated due to reflection of external light.

Accordingly, the technical problem of the present invention has been devised in this regard, and an object of the present invention is to provide a display panel with improved visibility by lowering reflectance by external light.

Another object of the present invention is to provide a method for manufacturing the display panel.

A display panel according to an exemplary embodiment for realizing the above object of the present invention includes a first switching element, a first pixel electrode including a material electrically connected to the first switching element and having a reflective property, the first pixel electrode Disposed on the first pixel electrode, a voltage applied to the first pixel electrode, a first emission layer emitting light of a first color, a thin protection film disposed on the first emission layer to protect the first emission layer, and the thin type A pressure sensitive adhesive layer disposed on the protective film, and a first color filter disposed on the pressure sensitive adhesive layer, corresponding to the first light emitting layer, and having the first color.

In one embodiment of the present invention, the display panel may further include a base layer disposed on the first color filter. The base layer may include any one of glass, metal and polymer materials.

In one embodiment of the present invention, when the base layer includes the polymer material, the polymer material is polyimide, polycarbonate, polyethylene terephthalate (PET), polyurethane (polyurethane) ), Polyacrynitril (PAN), polyethylene (polyethylene; PE), and polypropylene (polypropylene; PP).

In one embodiment of the present invention, the thin protective film may include a plurality of organic layers and inorganic layers that are alternately stacked.

In one embodiment of the present invention, the organic layers of the thin protective film may include an acrylate-based material. The inorganic layers may include an oxide-based material. The thin protective film may be formed at a temperature of 100 degrees or less (Celsius degree).

In one embodiment of the present invention, the light reflectivity of the first electrode may be 100%.

In one embodiment of the present invention, the switching element may include low temperature polysilicon formed by crystallization of an amorphous silicon thin film by a laser annealing method.

In one embodiment of the present invention, the low-temperature polysilicon may be formed by a process of 100 degrees (Celsius degree) or less.

In one embodiment of the present invention, the display panel is disposed on the second pixel electrode, the second pixel electrode including a second switching element, a material electrically connected to the second switching element, and having a reflective property, As a voltage is applied to the second pixel electrode, a second light emitting layer that emits light of a second color different from the first color, a third switching element, and a material that is electrically connected to the third switching element and has a reflective property A third pixel electrode including a third light emitting layer disposed on the third pixel electrode and emitting light of a third color different from the first and second colors as voltage is applied to the third pixel electrode , Disposed on the pressure sensitive adhesive layer, corresponding to the second light emitting layer, a second color filter having the second color, and disposed on the pressure sensitive adhesive layer, corresponding to the third light emitting layer, and the third color A third color filter which may be further included.

In one embodiment of the present invention, the first color is red, the second color is green, the third color is blue, and the height H1 of the first light emitting layer is The following conditions "2n _R (H1) = mλ _R or 2 n _R (H1) = (m + 1/2) λ _R (where n _R , λ _R are refractive indices of the first light emitting layer, respectively, incident red light Wavelength, and m means an integer) ", and the height (H2) of the second light emitting layer is as follows:" 2n _G (H2) = mλ _G or 2 n _G (H2) = (m +1/2) λ _G (where n _G and λ _G each represent the refractive index of the second light-emitting layer 162, the wavelength of the incident green light, and m means an integer) ”, and the third The height (H3) of the light emitting layer is the following condition "2n _B (H3) = mλ _B or 2 n _B (H3) = (m + 1/2) λ _B (where n _B , λ _B are respectively the third Refractive index of the light emitting layer 163, indicates the wavelength of the incident blue light, m means an integer) " have.

In one embodiment of the present invention, a base layer disposed on the first to third color filters may be further included. A black matrix disposed on the base layer to partition the first color filter, the second color filter, and the third color filter may be further included.

In one embodiment of the present invention, it may further include a lower protective film disposed under the base layer.

In one embodiment of the present invention, the pressure sensitive adhesive may include an acrylic polymer.

In one embodiment of the present invention, a base layer disposed between the first color filter and the thin protective film, and an overcoat layer disposed on the first color filter may be further included.

A method of manufacturing a display panel according to an exemplary embodiment for realizing the above object of the present invention includes a first switching element, a first pixel electrode including a material electrically connected to the first switching element and having a reflective property, the first A first protective layer disposed on one pixel electrode and emitting a light of a first color when a voltage is applied to the first pixel electrode, and a thin protective film disposed on the first emitting layer to protect the first emitting layer Forming a display substrate including; Forming an upper protective film comprising forming a first color filter having the first color on a base layer and forming a pressure sensitive adhesive layer on the first color filter; And bonding the thin protective film of the display substrate and the pressure sensitive adhesive layer of the upper protective film.

In one embodiment of the present invention, in the step of forming the display substrate, the switching element may include low temperature polysilicon formed by crystallizing an amorphous silicon thin film by a laser annealing method. You can.

In one embodiment of the present invention, forming the first color filter comprises: forming a black matrix on the base substrate; Applying a first color resist onto the base substrate on which the black matrix is formed; Exposing the first color resist using a patterned mask; And developing the first color resist to form the first color filter.

In one embodiment of the present invention, a pre-bake step of thermally curing the first color resist to 90 degrees to 110 degrees (Celsius degree) may be further included before the step of exposing.

In one embodiment of the present invention, after the step of forming the first color filter by developing the first color resist, post-baking to heat-cure the first color filter to 220 degrees to 230 degrees (Celsius degree). It may further include a (post-bake) step.

In one embodiment of the present invention, in the step of forming the display substrate, the thin protective film may be formed by alternately laminating a plurality of organic layers and inorganic layers.

According to embodiments of the present invention, since the display panel includes color filters each having the same color as the light of the color in which the light emitting layers emit light, the reflectance at the pixel electrode of external light can be reduced. Therefore, it is possible to improve the display quality of the display panel.

In addition, since the external protective film including the color filters is adhered to the display substrate including the light emitting layers using a pressure sensitive adhesive layer, even if the color filters are formed using a high temperature process, damage due to heat of the light emitting layers is reduced. I can do it.

In addition, in the case where the display panel is a flexible display, the color filter can be used as a substitute for a general polarizing plate used to lower reflectance, so that the thickness of the entire display panel can be reduced. Accordingly, flexibility of the display panel may be increased.

1 is a plan view of a display panel according to an exemplary embodiment of the present invention.
2 is a cross-sectional view taken along line II ′ of FIG. 1.
3 is a cross-sectional view of a display panel according to another exemplary embodiment of the present invention.
4 is a cross-sectional view of a display panel according to an exemplary embodiment of the present invention.
5A to 5C are cross-sectional views illustrating a method of manufacturing an upper protective film of the display panel of FIG. 2.
6A to 6C are cross-sectional views illustrating a method of manufacturing an upper protective film of the display panel of FIG. 3.
7A to 7G are cross-sectional views illustrating a method of manufacturing a display substrate of the display panel of FIG. 2.
8 is a cross-sectional view illustrating a step of bonding an upper protective film and a lower protective film to a display substrate to complete the display panel of FIG. 2.

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

1 is a plan view of a display panel according to an exemplary embodiment of the present invention. 2 is a cross-sectional view taken along line I-I 'of FIG. 1.

1 and 2, the display panel includes a display substrate 100, an upper protective film 300, and a lower protective film 200. The display panel includes a plurality of unit pixels. In the drawing, one unit pixel including the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3 will be described.

The display substrate 100 includes a base substrate 110, a buffer layer 120, a first insulating layer 130, a second insulating layer 140, first to third switching elements SW1, SW2, and SW3, Third insulating layer 150, first to third pixel electrodes PE1, PE2, PE3, pixel defining layer 160, first to third light emitting layers 161, 162, 163, common electrode CE ), And a thin encapsulation film 170.

The base substrate 110 may include an insulating substrate. In addition, the base substrate 110 may include a flexible substrate. For example, the base substrate 110 may be formed of a glass substrate, a quartz substrate, a resin substrate, and the like. For example, the resin substrate is polyimide-based resin, acrylic-based resin, polyacrylate-based resin, polycarbonate-based resin, polyether-based (polyether-based) resins, sulfonic acid-based resins, polyethylene terephthalate-based resins, and the like.

The buffer layer 120 is disposed on the base substrate 110. The buffer layer 120 prevents impurity diffusion from the base substrate 110, improves the flatness of the base substrate 110, and allows the uniform channel layer CH to be formed. The buffer layer 120 may be formed using a silicon compound. For example, the buffer layer 120 may include silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), silicon oxycarbide (SiOxCy), and / or silicon carbonitride (SiCxNy). have.

The channel layer CH is disposed on the buffer layer 120. The channel layer CH may include an LTPS thin film formed of a low temperature polysilicon in which an amorphous silicon thin film is crystallized by a laser annealing method. In addition, the channel layer CH may include a semiconductor layer made of amorphous silicon (a-Si: H) and a resistive contact layer made of n + amorphous silicon (n + a-Si: H). Also, the channel layer CH may include an oxide semiconductor.

The first insulating layer 130 is disposed on the buffer layer 120 on which the channel layer CH is disposed. The first insulating layer 130 may include silicon oxide, metal oxide, or the like.

The gate electrode GE is disposed on the first insulating layer 130 overlapping the channel layer CH. The gate electrode GE is electrically connected to the gate line GL. The gate electrode GE may include a metal, an alloy, a metal nitride, a conductive metal oxide, or a transparent conductive material.

The second insulating layer 140 is disposed on the first insulating layer 130 on which the gate electrode GE is disposed. The second insulating layer 140 may include silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), silicon oxycarbide (SiOxCy), silicon carbonitride (SiCxNy), and the like. In addition, the second insulating layer 140 is a single layer structure including silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), silicon oxycarbide (SiOxCy), and / or silicon carbonitride (SiCxNy). Or it may have a multi-layer structure.

The first contact hole C1 is formed through the first and second insulating layers 130 and 140 to expose a portion of the channel layer CH. The second contact hole C2 is formed through the first and second insulating layers 130 and 140 to expose a portion of the channel layer CH.

The source electrode SE and the drain electrode DE are disposed on the second insulating layer 140. The source electrode SE is electrically connected to the channel layer CH through the first contact hole C1. The drain electrode DE is electrically connected to the channel layer CH through the second contact hole C2. The source electrode SE and the drain electrode DE may include metal, alloy, metal nitride, conductive metal oxide, and transparent conductive material.

The channel layer CH, the gate electrode GE, the source electrode SE, and the drain electrode DE constitute the first switching element SW1. The first switching element SW1 is formed corresponding to the first sub-pixel SP1. Similarly, the second switching element SW2 is formed corresponding to the second sub-pixel SP2, and the third switching element SW3 is formed corresponding to the third sub-pixel SP3.

The third insulating layer 150 is disposed on the second insulating layer 130 on which the source and drain electrodes SE and DE are disposed. The third insulating layer 150 may include an organic material. For example, the insulating layer 90 may include photoresist, acrylic resin, polyimide resin, polyamide resin, siloxane-based resin, and the like. In addition, the third insulating layer 150 may include inorganic materials such as silicon compounds, metals, and metal oxides. The third insulating layer 150 may be formed in a single layer structure, but may also be formed in a multi-layer structure including at least two insulating films.

The third contact hole CH3 is formed through the third insulating layer 150 to expose a portion of the drain electrode DE.

The first to third pixel electrodes PE1, PE2, and PE3 are disposed on the third insulating layer 150. The first pixel electrode PE1 is electrically connected to the drain electrode DE of the first switching element SW1 through the third contact hole CH3. The first pixel electrode PE1 is formed corresponding to the first sub-pixel SP1. Similarly, the second pixel electrode PE2 is formed corresponding to the second sub-pixel SP2 and is electrically connected to the second switching element SW2. The third pixel electrode PE3 is formed corresponding to the third sub-pixel SP3 and is electrically connected to the third switching element SW3.

The first to third pixel electrodes PE1, PE2, and PE3 may include a reflective material. The first to third pixel electrodes PE1, PE2, and PE3 may preferably have a reflectivity of about 100%. For example, the first to third pixel electrodes PE1, PE2, and PE3 include the aluminum, aluminum-containing alloy, aluminum nitride, silver, silver-containing alloy, tungsten, tungsten nitride, copper, and copper. Alloys containing, nickel, chromium, chromium nitride, molybdenum, alloys containing molybdenum, titanium, titanium nitride, platinum, tantalum, tantalum nitride, neodymium, scandium, strontium ruthenium oxide, zinc oxide, indium tin oxide, Tin oxide, indium oxide, gallium oxide, indium zinc oxide, and the like.

The pixel defining layer 160 is disposed on the third insulating layer 150 on which the first to third pixel electrodes PE1, PE2, and PE3 are disposed. Openings exposing the first to third pixel electrodes PE1, PE2, and PE3 are formed in the pixel defining layer 160.

The pixel defining layer 160 may include organic materials, inorganic materials, and the like. For example, the pixel defining layer 160 may include photoresist, polyacrylic resin, polyimide resin, acrylic resin, and silicone compound.

The first to third light emitting layers 161, 162, and 163 are disposed on the first to third pixel electrodes PE1, PE2, and PE3 exposed through openings in the pixel defining layer 160, respectively. . Also, the first to third light emitting layers 161, 162, and 163 may extend on sidewalls of the openings of the pixel defining layer 160. Each of the first to third light emitting layers 161, 162, and 163 may be formed using light emitting materials capable of generating different color lights. The first emission layer 161 is formed corresponding to the first sub-pixel SP1 and generates light of a first color. For example, the first emission layer 161 may emit red light. The second emission layer 162 is formed corresponding to the second sub-pixel SP2 and generates light of a second color different from the first color. For example, the second emission layer 162 may emit green light. The third emission layer 163 is formed corresponding to the third sub-pixel SP3, and generates a third color light different from the first and second colors. For example, the third emission layer 163 may emit blue light.

The common electrode CE is disposed on the pixel defining layer 160 on which the first to third light emitting layers 161, 162, and 163 are disposed. The common electrode CE may include a material having light transmittance or a material having reflectivity. For example, the common electrode CE is aluminum, an alloy containing aluminum, aluminum nitride, silver, an alloy containing silver, tungsten, tungsten nitride, copper, an alloy containing copper, nickel, chromium, chromium nitride, Molybdenum, alloys containing molybdenum, titanium, titanium nitride, platinum, tantalum, tantalum nitride, neodymium, scandium, strontium ruthenium oxide, zinc oxide, indium tin oxide, tin oxide, indium oxide, gallium oxide, indium zinc Oxides and the like.

The thin protective film 170 is disposed on the common electrode CE. The thin protective film 170 protects the first to third light emitting layers 161, 162, and 163.

The thin protective film 170 includes a plurality of organic and inorganic layers that are alternately stacked. For example, the thin protective film 170 is sequentially stacked first organic layer 171, first inorganic layer 172, second organic layer 173, second inorganic layer 174, and third organic layer It may include (175). The first, second and third organic layers 171, 173, and 175 include an acrylate-based material, and the first and second inorganic layers 172 and 174 are oxides. It may contain a series of substances. The thin protective film 170 may be manufactured in a low temperature process in order not to damage the first to third light emitting layers 161, 162, and 163. For example, the thin protective film 170 may be manufactured at a temperature of 100 degrees or less. Therefore, the thin protective film 170 may be directly formed on the common electrode CE. The thin protective film 170 may have a thickness of about 1 to 10 μm (micrometer).

The lower protective film 200 includes a first base layer 210 and a first pressure sensitive adhesive (220). The lower protective film 200 protects the lower portion of the display substrate 100.

The first base layer 210 may include glass, metal, or polymer materials. When the first base layer 210 includes a polymer material, polyimide, polycarbonate, polyethylene terephthalate (PET), polyurethane, polyurethane, polyacrynitril (PAN) ), Polyethylene (polyethylene; PE), polypropylene (polypropylene; PP), and the like. The first base layer 210 may preferably have a thickness of 75 μm (micrometer).

The first pressure sensitive adhesive (220) is disposed between the first base layer 210 and the base substrate 110 of the label substrate 100. The first pressure sensitive adhesive layer 220 bonds the lower protective film 200 on the base substrate 110 of the label substrate 100. The first pressure sensitive adhesive layer 220 may function as pressure is applied. For example, the first pressure sensitive adhesive layer 220 may include an acrylic polymer. The first pressure sensitive adhesive layer 220 may preferably have a thickness of about 25 μm (micrometer).

The upper protective film 300 includes a second base layer 310, a black matrix (BM), first to third color filters CF1, CF2, and CF3 and a second pressure sensitive adhesive layer 320. The upper protective film 300 protects the upper portion of the display substrate 100.

The second base layer 310 may include glass, metal, or polymer materials. When the second base layer 310 includes a polymer material, polyimide, polycarbonate, polyethylene terephthalate (PET), polyurethane, polyurethane, polyacrynitril (PAN) ), Polyethylene (polyethylene; PE), polypropylene (polypropylene; PP), and the like. The second base layer 310 may preferably have a thickness of 100 μm (micrometer).

Since the black matrix BM and the first to third color filters CF1, CF2, and CF3 must be formed on the second base layer 310, the heat resistance temperature of the second base layer 310 is the The black matrix (BM) and the first to third color filters (CF1, CF2, CF3) is preferably about 200 degrees to about 300 degrees (Celsius degree) higher than the manufacturing process temperature.

The black matrix BM is disposed on the first base layer 310. The black matrix BM overlaps wiring of the data line DL, the gate line GL, and the switching elements SW1, SW2, and SW3, and includes a light blocking material. The black matrix BM defines a boundary with neighboring sub-pixels.

The first to third color filters CF1, CF2, and CF3 are disposed on the first base layer 310 on which the black matrix BM is disposed. The first to third color filters CF1, CF2, and CF3 are respectively disposed to correspond to the first to third sub pixels SP1, SP2, and SP3. In addition, the first to third color filters CF1, CF2, and CF3 are disposed to correspond to the first to third light emitting layers 161, 162, and 163, respectively. The first color filter CF1 has the same color as the light of the first color of the first emission layer 161. For example, when the first light emitting layer 161 emits red light, the first color filter CF1 may be red. The second color filter CF2 has the same color as the light of the second color of the second emission layer 162. For example, when the second emission layer 162 emits green light, the second color filter CF2 may be green. The third color filter CF3 has the same color as the light of the third color of the third emission layer 163. For example, when the third emission layer 163 emits blue light, the third color filter CF3 may be blue.

The black matrix BM and the first to third color filters CF1, CF2, and CF3 may be formed according to a general black matrix and color filter manufacturing process in the art. For example, a pre-bake step of about 90 to 110 degrees (Celsius degree) and a post of about 220 to 230 degrees (Celsius degree) as a manufacturing process of a black matrix and a color filter used in a liquid crystal display device A process comprising a post-bake step can be used.

The second pressure sensitive adhesive layer 320 is disposed on the black matrix BM and the first to third color filters CF1, CF2, and CF3. The second pressure sensitive adhesive layer 320 bonds the upper protective film 300 on the thin protective film 170 of the label substrate 100. The second pressure sensitive adhesive layer 320 may perform an adhesive action as pressure is applied. For example, the second pressure sensitive adhesive layer 320 may include an acrylic polymer. The second pressure sensitive adhesive layer 320 may preferably have a thickness of about 100 μm (micrometer).

3 is a cross-sectional view of a display panel according to another exemplary embodiment of the present invention.

Referring to FIG. 3, the display panel is substantially the same as the display panel of FIG. 2 except for the upper protective film 400. Accordingly, overlapping descriptions are simplified or omitted.

The display panel includes a display substrate 100, an upper protective film 400 and a lower protective film 400. The display panel includes a plurality of unit pixels. In the drawing, one unit pixel including the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3 will be described.

The display substrate 100 includes a base substrate, a buffer layer, a first insulating layer, a second insulating layer, first to third switching elements, first to third pixel electrodes, a pixel defining layer, and first to third light emitting layers Field, common electrode, and thin protective film. The lower protective film 200 includes a first base layer 210 and a first pressure sensitive adhesive layer 220. (See Figure 2)

The upper protective film 400 includes a second base layer 410, a black matrix (BM), first to third color filters (CF1, CF2, CF3), a second pressure sensitive adhesive layer 420, and an overcoat layer ( 430). The upper protective film 400 protects the upper portion of the display substrate 100.

The second base layer 410 may include glass, metal, or polymer materials. When the second base layer 410 comprises a polymer material, polyimide, polycarbonate, polyethylene terephthalate (PET), polyurethane, polyurethane, polyacrynitril (PAN) ), Polyethylene (polyethylene; PE), polypropylene (polypropylene; PP), and the like. The second base layer 410 may preferably have a thickness of 100 μm (micrometer).

Since the black matrix BM and the first to third color filters CF1, CF2, and CF3 must be formed on the second base layer 410, the heat-resistant temperature of the second base layer 410 is the The black matrix (BM) and the first to third color filters (CF1, CF2, CF3) is preferably about 200 degrees to about 300 degrees (Celsius degree) higher than the manufacturing process temperature.

The black matrix BM is disposed on the first base layer 410. The black matrix BM overlaps wirings such as data lines, gate lines, and switching elements (see FIG. 2), and includes a light blocking material. The black matrix BM defines a boundary with neighboring sub-pixels.

The first to third color filters CF1, CF2, and CF3 are disposed on the first base layer 410 on which the black matrix BM is disposed. The first to third color filters CF1, CF2, and CF3 are respectively disposed to correspond to the first to third sub pixels SP1, SP2, and SP3. Further, the first to third color filters CF1, CF2, and CF3 are disposed to correspond to the first to third light emitting layers 161, 162, and 163, respectively. The first color filter CF1 has the same color as the light of the first color of the first emission layer 161. For example, when the first light emitting layer 161 emits red light, the first color filter CF1 may be red. The second color filter CF2 has the same color as the light of the second color of the second emission layer 162. For example, when the second emission layer 162 emits green light, the second color filter CF2 may be green. The third color filter CF3 has the same color as the light of the third color of the third emission layer 163. For example, when the third emission layer 163 emits blue light, the third color filter CF3 may be blue.

Since the first to third color filters 161, 162, and 163 each have the same color as the light of the first to third colors of the first to third light emitting layers 161, 162, and 163, inside the display panel Only light having a specific wavelength of external light reflected through the first to third pixel electrodes PE1, PE2, and PE3 passes through the color filter. Therefore, external light is reflected from the first to third pixel electrodes PE1, PE2, and PE3 to prevent deterioration of display quality, thereby improving display quality of the display panel.

The black matrix BM and the first to third color filters CF1, CF2, and CF3 may be formed according to a general black matrix and color filter manufacturing process in the art. For example, a pre-bake step of about 90 to 110 degrees (Celsius degree) and a post of about 220 to 230 degrees (Celsius degree) as a manufacturing process of a black matrix and a color filter used in a liquid crystal display device A process comprising a post-bake step can be used.

The overcoat layer 430 is disposed on the black matrix BM and the first to third color filters CF1, CF2, and CF3. The overcoat layer 430 serves to protect and insulate the first to third color filters CF1, CF2, and CF3 while flattening, and may be formed using an acrylic epoxy material.

The second pressure-sensitive adhesive layer 420 is disposed under the second base layer 410. That is, the second pressure sensitive adhesive layer 420 is in the opposite direction of the black matrix BM and the first to third color filters CF1, CF2, and CF3 based on the second base layer 410. Is placed. The second pressure sensitive adhesive layer 420 bonds the upper protective film 400 on the thin protective film 170 of the label substrate 100. The second pressure-sensitive adhesive layer 420 may function as pressure is applied. For example, the second pressure sensitive adhesive layer 420 may include an acrylic polymer. The second pressure sensitive adhesive layer 420 may preferably have a thickness of about 100 μm (micrometer).

4 is a cross-sectional view of a display panel according to an exemplary embodiment of the present invention.

Referring to FIG. 4, since the display panel is substantially the same as the display panel of FIG. 2 except for the first to third light emitting layers 161, 162, and 163 and the pixel defining layer 160, overlapping descriptions will be simplified or Omitted.

The display panel includes a display substrate 100, an upper protective film 400 and a lower protective film 400. The display panel includes a plurality of unit pixels. In the drawing, one unit pixel including the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3 will be described.

The display substrate 100 includes a base substrate 110, a buffer layer 120, a first insulating layer 130, a second insulating layer 140, first to third switching elements SW1, SW2, and SW3, Third insulating layer 150, first to third pixel electrodes PE1, PE2, PE3, pixel defining layer 160, first to third light emitting layers 161, 162, 163, common electrode CE ), And a thin encapsulation film 170.

The pixel defining layer 160 is disposed on the third insulating layer 150 on which the first to third pixel electrodes PE1, PE2, and PE3 are disposed. Openings exposing the first to third pixel electrodes PE1, PE2, and PE3 are formed in the pixel defining layer 160.

The pixel defining layer 160 is disposed on the third insulating layer 150 on which the first to third pixel electrodes PE1, PE2, and PE3 are disposed. Openings exposing the first to third pixel electrodes PE1, PE2, and PE3 are formed in the pixel defining layer 160. The height of the pixel defining layer 160 may be formed differently for each sub-pixel depending on the height of the first to third light emitting layers 161, 162, and 163.

The pixel defining layer 160 may include organic materials, inorganic materials, and the like. For example, the pixel defining layer 160 may include photoresist, polyacrylic resin, polyimide resin, acrylic resin, and silicone compound.

The first to third light emitting layers 161, 162, and 163 are disposed on the first to third pixel electrodes PE1, PE2, and PE3 exposed through openings in the pixel defining layer 160, respectively. . Also, the first to third light emitting layers 161, 162, and 163 may extend on sidewalls of the openings of the pixel defining layer 160. Each of the first to third light emitting layers 161, 162, and 163 may be formed using light emitting materials capable of generating different color lights. The first emission layer 161 is formed corresponding to the first sub-pixel SP1 and generates light of a first color. For example, the first emission layer 161 may emit red light. The second emission layer 162 is formed corresponding to the second sub-pixel SP2 and generates light of a second color different from the first color. For example, the second emission layer 162 may emit green light. The third emission layer 163 is formed corresponding to the third sub-pixel SP3, and generates a third color light different from the first and second colors. For example, the third emission layer 163 may emit blue light.

The first to third light emitting layers 161, 162, and 163 may have different heights. The first to third light emitting layers 161, 162, and 163 each have an appropriate height, and in order to minimize reflection by external light, the first to third pixel electrodes PE1, PE2, and PE3 are used. Offset interference due to reflection of the external light at the common electrode CE may be used. The first to third light emitting layers 161, 162, and 163 have a thickness depending on color wavelength and refractive index.

For example, the first emission layer 161 may emit red light, the second emission layer 162 may emit green light, and the third emission layer 163 may emit blue light. At this time, due to the semi-transparent property of the common electrode CE, external light is partially reflected from the common electrode CE, and the other part is transmitted through the common electrode CE. After the red light of the external light passing through the common electrode CE passes through the first light emitting layer 161 and is reflected by the first pixel electrode PE1, the first light emitting layer 161 and the common electrode CE ). Here, the red light of the external light reflected from the first pixel electrode PE1 and the red light of the external light transmitted through the common electrode CE and then reflected by the first pixel electrode PE1 cause offset interference. If it is, it is possible to reduce the reflectance of the red light incident from the outside.

The height (H1) of the first light emitting layer 161 is the following conditions,

2n _R (H1) = mλ _R or 2 n _R (H1) = (m + 1/2) λ _R

(Wherein, n _R , λ _R respectively represents the refractive index of the first light emitting layer 161, the wavelength of the incident red light, m is an integer)

If satisfactory, red light reflected from the common electrode CE and red light transmitted through the common electrode CE and then reflected from the first pixel electrode PE1 may cause interference. Accordingly, the reflectance of red light incident from the outside can be reduced.

Similarly, the height (H2) of the second light emitting layer 162 is the following conditions,

2n _G (H2) = mλ _G or 2 n _G (H2) = (m + 1/2) λ _G

(Wherein, n _G , λ _G represents the refractive index of the second light emitting layer 162, the wavelength of the incident green light, m is an integer)

Also, similarly, the height H3 of the third light emitting layer 163 is as follows:

2n _B (H3) = mλ _B or 2 n _B (H3) = (m + 1/2) λ _B

(Wherein, n _B , λ _B represents the refractive index of each of the third light emitting layer 163, the wavelength of the incident blue light, m is an integer)

5A to 5C are cross-sectional views illustrating a method of manufacturing an upper protective film of the display panel of FIG. 2. The manufacturing method of the upper protective film includes forming a black matrix (BM), forming first to third color filters (CF1, CF2, CF3), and forming a second pressure sensitive adhesive layer (320). Includes steps.

Referring to FIG. 5A, in the step of forming the black matrix BM, a black matrix BM is formed on the second base layer 310.

A light blocking material is coated on the second base layer 310 by a sputtering method, after exposure using a mask having a pattern, and developed to form the black matrix BM. The second base layer 310 may include glass, metal, or polymer materials. When the second base layer 310 includes a polymer material, polyimide, polycarbonate, polyethylene terephthalate (PET), polyurethane, polyurethane, polyacrynitril (PAN) ), Polyethylene (polyethylene; PE), polypropylene (polypropylene; PP), and the like. The second base layer 310 may preferably have a thickness of 100 μm (micrometer). The light blocking material may include a metal such as chromium (Cr) or a carbon-based organic material.

Referring to FIG. 5B, in forming the first to third color filters CF1, CF2, and CF3, first to third on the second base layer 310 on which the black matrix BM is formed. Three color filters CF1, CF2, and CF3 are formed. The first to third color filters CF1, CF2, and CF3 are respectively formed corresponding to the first to third sub-pixels (see SP1 to SP3 in FIG. 5C), and neighboring color filters and the black matrix BM ) May partially overlap. The first to third color filters CF1, CF2, and CF3 may be sequentially formed.

The forming of the first color filter CF1 includes applying a first color resist onto the second base layer 310 on which the black matrix BM is formed, and exposing using a mask having a pattern. And developing the first color resist to form a first color filter CF1.

In this case, a vacuum drying step and / or a pre-bake step may be further included before the exposing step. In the pre-baking step, the first color resist may be thermally cured to about 90 degrees to about 110 degrees (Celsius degree). Also, a post-bake step of thermally curing the first color filter CF1 after the developing step may be further included. In the post-baking step, the first color filter CF1 may be thermally cured to about 220 to about 230 degrees (Celsius degree).

The forming of the second color filter CF2 includes applying a second color resist onto the second base layer 310 on which the first color filter CF1 is formed, and exposing using a mask having a pattern. And forming a second color filter CF2 by developing the second color resist.

In this case, a vacuum drying step and / or a pre-bake step may be further included before the exposing step. In the pre-baking step, the second color resist may be thermally cured to about 90 degrees to about 110 degrees (Celsius degree). Also, a post-bake step of thermally curing the second color filter CF2 after the developing step may be further included. In the post-baking step, the second color filter CF2 may be thermally cured to about 220 to about 230 degrees (Celsius degree).

The forming of the third color filter CF3 includes applying a third color resist onto the second base layer 310 on which the first and second color filters CF1 and CF2 are formed, and patterning. The method may include exposing using a mask having, and developing the third color resist to form a third color filter CF3.

In this case, a vacuum drying step and / or a pre-bake step may be further included before the exposing step. In the pre-baking step, the third color resist may be thermally cured to about 90 degrees to about 110 degrees (Celsius degree). In addition, a post-bake step of thermally curing the third color filter CF3 after the developing step may be further included. In the post-baking step, the third color filter CF3 may be thermally cured to about 220 to about 230 degrees (Celsius degree).

Meanwhile, the first to third color filters CF1, CF2, and CF3 may be formed by an inkjet method.

Referring to FIG. 5C, in the step of forming the second pressure sensitive adhesive layer 320, a second pressure sensitive adhesive layer on the first to third color filters CF1, CF2, CF3 and the black matrix BM ( 320). The second pressure sensitive adhesive layer 320 may be formed by adhering a separate adhesive tape on the first to third color filters CF1, CF2, CF3 and the black matrix BM. For example, the second pressure sensitive adhesive layer 320 may be a tape comprising an acrylic polymer. The second pressure sensitive adhesive layer 320 may preferably have a thickness of about 100 μm (micrometer).

6A to 6C are cross-sectional views illustrating a method of manufacturing an upper protective film of the display panel of FIG. 3. The manufacturing method of the upper protective film is the same as the manufacturing method of the upper protective film of FIGS. 5A to 5C, except for forming the overcoat layer 430 and forming the second pressure sensitive adhesive layer 420, Redundant descriptions are simplified or omitted.

The manufacturing method of the upper protective film includes forming a black matrix (BM), forming first to third color filters (CF1, CF2, CF3), forming an overcoat layer 430, and a second And forming a pressure sensitive adhesive layer 420.

Referring to FIG. 6A, in the step of forming the black matrix BM, the black matrix BM is formed on the second base layer 310. A light blocking material is coated on the second base layer 410 by a sputtering method, and exposed using a mask having a pattern, followed by development to form the black matrix BM.

Referring to FIG. 6A again, in the step of forming the first to third color filters CF1, CF2, and CF3, the first to third colors are formed on the second base layer 410 on which the black matrix BM is formed. The third color filters CF1, CF2, and CF3 are formed. The first to third color filters CF1, CF2, and CF3 are respectively formed corresponding to the first to third sub-pixels (see SP1 to SP3 in FIG. 6C), and neighboring color filters and the black matrix BM ) May partially overlap. The first to third color filters CF1, CF2, and CF3 may be sequentially formed.

The forming of the first color filter CF1 includes applying a first color resist onto the second base layer 410 on which the black matrix BM is formed, and exposing using a mask having a pattern. And developing the first color resist to form a first color filter CF1.

In this case, a vacuum drying step and / or a pre-bake step may be further included before the exposing step. In the pre-baking step, the first color resist may be thermally cured to about 90 degrees to about 110 degrees (Celsius degree). Also, a post-bake step of thermally curing the first color filter CF1 after the developing step may be further included. In the post-baking step, the first color filter CF1 may be thermally cured to about 220 to about 230 degrees (Celsius degree).

The forming of the second color filter CF2 includes applying a second color resist onto the second base layer 410 on which the first color filter CF1 is formed, and exposing using a mask having a pattern. And forming a second color filter CF2 by developing the second color resist.

In this case, a vacuum drying step and / or a pre-bake step may be further included before the exposing step. In the pre-baking step, the second color resist may be thermally cured to about 90 degrees to about 110 degrees (Celsius degree). Also, a post-bake step of thermally curing the second color filter CF2 after the developing step may be further included. In the post-baking step, the second color filter CF2 may be thermally cured to about 220 to about 230 degrees (Celsius degree).

The forming of the third color filter CF3 is performed by applying a third color resist onto the second base layer 410 on which the first and second color filters CF1 and CF2 are formed. The method may include exposing using a mask having, and developing the third color resist to form a third color filter CF3.

In this case, a vacuum drying step and / or a pre-bake step may be further included before the exposing step. In the pre-baking step, the third color resist may be thermally cured to about 90 degrees to about 110 degrees (Celsius degree). In addition, a post-bake step of thermally curing the third color filter CF3 after the developing step may be further included. In the post-baking step, the third color filter CF3 may be thermally cured to about 220 to about 230 degrees (Celsius degree).

Meanwhile, the first to third color filters CF1, CF2, and CF3 may be formed by an inkjet method.

Referring to FIG. 6B, in forming the overcoat layer 430, an overcoat layer 430 is formed on the black matrix BM and the first to third color filters CF1, CF2, and CF3. do. The overcoat layer 430 serves to protect and insulate the first to third color filters CF1, CF2, and CF3 while flattening, and may be formed using an acrylic epoxy material.

Referring to FIG. 6C, in the step of forming the second pressure sensitive adhesive layer 420, a second pressure sensitive adhesive layer 320 is formed under the second base layer 410. That is, the second pressure sensitive adhesive layer 420 is in the opposite direction of the black matrix BM and the first to third color filters CF1, CF2, and CF3 based on the second base layer 410. Is formed. The second pressure-sensitive adhesive layer 320 may be formed by adhering a separate adhesive tape on the second base layer 410. For example, the second pressure sensitive adhesive layer 420 may be a tape comprising an acrylic polymer. The second pressure sensitive adhesive layer 420 may preferably have a thickness of about 100 μm (micrometer).

7A to 7G are cross-sectional views illustrating a method of manufacturing a display substrate of the display panel of FIG. 2. In the drawing, one sub-pixel will be described.

Referring to FIG. 7A, a buffer layer 120 is formed on the base substrate 110. The buffer layer 120 includes a spin coating process, a chemical vapor deposition (CVD) process, a plasma enhanced chemical vapor deposition (PECVD) process, a high density plasma-chemical vapor deposition (HDP-CVD) process, and a printing process. And the like.

A channel layer CH is formed on the buffer layer 120. After forming a semiconductor layer on the buffer layer 120, the semiconductor layer is patterned to form the channel layer CH. The channel layer CH may be formed using a chemical vapor deposition process, a plasma enhanced chemical vapor deposition process, a low pressure chemical vapor deposition process, a sputtering process, or the like. In addition, the channel layer CH may be low temperature polysilicon formed by crystallizing an amorphous silicon thin film by a laser annealing method.

Referring to FIG. 7B, a first insulating layer 130 is formed on the buffer layer 120 on which the channel layer CH is formed. The first insulating layer 130 may be formed using a chemical vapor deposition process, a spin coating process, a plasma-enhanced chemical vapor deposition process, a sputtering process, a vacuum deposition process, a high-density plasma-chemical vapor deposition process, a printing process, or the like. .

Referring to FIG. 7C, a gate electrode GE overlapping the channel layer CH is formed on the first insulating layer 130. After the conductive layer is formed on the first insulating layer 130, the gate electrode GE may be formed by patterning the conductive layer using a photolithography process or an etching process using an additional etching mask.

A second insulating layer 140 is formed on the first insulating layer 130 on which the gate electrode GE is formed. The second insulating layer 140 may be formed using a spin coating process, a chemical vapor deposition process, a plasma enhanced chemical vapor deposition process, a high-density plasma-chemical vapor deposition process, or the like.

Referring to FIG. 7D, first and second contact holes (see C1 and C2 of FIG. 1) exposing a portion of the channel layer CH are through the first and second insulating layers 130 and 140. Is formed. The first and second contact holes may be formed through a photolithography process or an etching process using an additional mask.

A source electrode SE and a drain electrode DE are formed on the second insulating layer 140 on which the first and second contact holes are formed. The source electrode SE is electrically connected to the channel layer CH through the first contact hole C1. The drain electrode DE is electrically connected to the channel layer CH through the second contact hole C2. After forming a conductive layer on the second insulating layer 140, the conductive layer is patterned using a photolithography process or an etching process using an additional etching mask to form the source electrode SE and the drain electrode DE. Can form.

A third insulating layer 150 is formed on the second insulating layer 140 on which the source electrode SE and the drain electrode DE are formed. The third insulating layer 150 is a spin coating process, a printing process, a sputtering process, a chemical vapor deposition process, an atomic layer deposition process, a plasma enhanced chemical vapor deposition process, a high density plasma-chemical vapor deposition process, vacuum It may be formed using a deposition process or the like.

Referring to FIG. 7E, a third contact hole exposing a portion of the drain electrode DE (see C3 in FIG. 1) is formed through the third insulating layer 150. The third contact hole may be formed through a photolithography process or an etching process using an additional mask.

A first pixel electrode 161 is formed on the third insulating layer 150 on which the third contact hole is formed. The first pixel electrode PE1 is electrically connected to the drain electrode DE through the third contact hole. The first pixel electrode PE1 may be formed using a printing process, sputtering process, chemical vapor deposition process, atomic layer deposition process, vacuum deposition process, pulse laser deposition process, or the like.

A pixel defining layer 160 may be formed on the third insulating layer 150 on which the first pixel electrode PE1 is formed. The pixel defining layer 160 may be formed using a spin coating process, a spray process, a printing process, a chemical vapor deposition process, or the like.

Referring to FIG. 7F, a first emission layer 161 is formed on the first pixel electrode PE1 partitioned by the pixel defining layer 160. The first light emitting layer 161 may be formed using a laser transfer process, a printing process, or the like.

The common electrode CE is formed on the pixel defining layer 160 and the first pixel electrode PE1. The common electrode CE may be formed using a printing process, sputtering process, chemical vapor deposition process, atomic layer deposition process, vacuum deposition process, pulse laser deposition process, or the like.

Referring to FIG. 7G, a thin protective film 170 is formed on the common electrode CE. The thin protective film 170 is formed by alternately stacking a plurality of organic and inorganic layers. The thin protective film 170 may be formed in a low temperature process of about 100 degrees or less (Celsius degree). The thin protective layer 170 may be directly formed on the common electrode CE without damaging the first emission layer 161 by the low temperature process. For example, the thin protective film 170 is sequentially stacked first organic layer 171, first inorganic layer 172, second organic layer 173, second inorganic layer 174, and third organic layer It may include (175). The first organic layer 171 is formed on the common electrode CE, and the first inorganic layer 172 is formed on the first organic layer 171. The second organic layer 173 is formed on the first inorganic layer 172, and the second inorganic layer 174 is formed on the second organic layer 173. The third organic layer 175 is formed on the second inorganic layer 174.

8 is a cross-sectional view illustrating a step of bonding an upper protective film and a lower protective film to a display substrate to complete the display panel of FIG. 2.

The display substrate 100 may be completed, and the upper protective film 300 and the lower protective film 200 may be completed in separate processes. Thereafter, the first pressure sensitive adhesive layer 220 of the lower protective film 200 is adhered to the base substrate 110 of the display substrate 100 by pressure, and the thin protective film 170 of the display substrate 100 ), The second pressure sensitive adhesive layer 320 of the upper protective film 300 is pressure-bonded to complete the display panel.

According to embodiments of the present invention, since the display panel includes color filters each having the same color as the light of the color in which the light emitting layers emit light, the reflectance at the pixel electrode of external light can be reduced. Therefore, it is possible to improve the display quality of the display panel.

In addition, since the external protective film including the color filters is adhered to the display substrate including the light emitting layers using a pressure sensitive adhesive layer, even if the color filters are formed using a high temperature process, damage due to heat of the light emitting layers is reduced. I can do it.

In addition, in the case where the display panel is a flexible display, the color filter can be used as a substitute for a general polarizing plate used to lower reflectance, so that the thickness of the entire display panel can be reduced. Accordingly, flexibility of the display panel may be increased.

Although described with reference to the above embodiments, those skilled in the art understand that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. Will be able to.

100: display panel 110: base substrate
120: buffer layer 130: first insulating layer
140: second insulating layer 150: third insulating layer
160: pixel defining layer 161: first emitting layer
162: second light emitting layer 163: third light emitting layer
170: thin protective film 200: lower protective film
210: first base layer 220: first pressure sensitive adhesive layer
300: upper protective film 310: second base layer
320: second pressure sensitive adhesive layer BM: black matrix
CF1, CF2, CF3: 1-3 color filter
PE1, PE2, PE3: 1-3 pixel electrodes
SW1, SW2, SW3: 1-3th switching element

Claims (13)

A first switching element;
A first pixel electrode electrically connected to the first switching element;
A first emission layer disposed on the first pixel electrode and emitting light of a first color when a voltage is applied to the first pixel electrode;
A thin protective film disposed on the first light emitting layer to protect the first light emitting layer;
A first color filter disposed on the thin protective film, corresponding to the first light emitting layer, and having a first color filter having the first color,
A base layer disposed between the first color filter and the thin protective film; And
And an over-coating layer disposed on the first color filter. According to claim 1,
The base layer is a display panel, characterized in that it comprises any one of glass, metal and polymeric materials. According to claim 2,
When the base layer includes the polymer material, the polymer material is polyimide, polycarbonate, polyethylene terephthalate (PET), polyurethane, polyacrynitril (PAN) ), Polyethylene (PE), and polypropylene (polypropylene; PP). According to claim 1,
The thin protective film includes a plurality of organic layers and inorganic layers that are alternately stacked. According to claim 4,
The organic layers of the thin protective film include an acrylate-based material, the inorganic layers include an oxide-based material, and the thin protective film is at a temperature of 100 degrees or less (Celsius degree) or less. Display panel characterized in that formed. According to claim 1,
The first electrode has a light reflectance of 100%. According to claim 1,
The switching element is a display panel, characterized in that it comprises a low-temperature polysilicon formed by crystallizing an amorphous silicon thin film by a laser annealing method. The display panel of claim 7, wherein the low-temperature polysilicon is formed by a process of 100 degrees or less. According to claim 1,
A second switching element;
A second pixel electrode electrically connected to the second switching element;
A second emission layer disposed on the second pixel electrode and emitting light of a second color different from the first color when a voltage is applied to the second pixel electrode;
A third switching element;
A third pixel electrode electrically connected to the third switching element;
A third emission layer disposed on the third pixel electrode and emitting light of a third color different from the first and second colors when a voltage is applied to the third pixel electrode;
A second color filter corresponding to the second light emitting layer and having the second color; And
A display panel further comprising a third color filter corresponding to the third light emitting layer and having the third color. The method of claim 9,
The first color is red, the second color is green, and the third color is blue,
The height (H1) of the first light emitting layer is the following conditions
"2n _R (H1) = mλ _R or 2 n _R (H1) = (m + 1/2) λ _R
(Where, n _R and λ _R each represent the refractive index of the first light emitting layer and the wavelength of the incident red light, and m means an integer). "
The height (H2) of the second light emitting layer is as follows
"2n _G (H2) = mλ _G or 2 n _G (H2) = (m + 1/2) λ _G
(Where, n _G and λ _G represent the refractive index of the second light-emitting layer 162 and the wavelength of the incident green light, and m means an integer). "
The height (H3) of the third light emitting layer is as follows
"2n _B (H3) = mλ _B or 2 n _B (H3) = (m + 1/2) λ _B
(Wherein, n _B , λ _B each represents the refractive index of the third light emitting layer 163, the wavelength of the incident blue light, m is an integer) ", characterized in that the display panel. The method of claim 9,
A black matrix further comprising a base layer disposed on the first to third color filters, and disposed on the base layer to partition the first color filter, the second color filter, and the third color filter. Display panel characterized in that it further comprises The method of claim 11,
And a lower protective film disposed under the base layer. According to claim 1,
Further comprising a pressure-sensitive adhesive layer disposed on the thin protective film,
The pressure sensitive adhesive is a display panel characterized in that it comprises an acrylic polymer.

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