DISPLAY PANEL AND METHOD FOR MANUFACTURING SAME

A display panel and a preparation method thereof are provided. A first display region and a second display region are defined on the display panel, and the display panel includes: a substrate, a driving device layer, and a light-emitting device layer. In the second display region, the driving device layer is further provided with a dummy through hole located within an orthographic projection range of at least one of the light-emitting subpixels on the substrate, and the dummy through hole and the at least one light-emitting subpixel are insulated from each other. The display panel can ensure the electrical uniformity between thin film transistors (TFTs) in the second display region, thereby alleviating non-uniform display.

This application claims priority to Chinese Patent Application No. 202110897314.6, filed with the China National Intellectual Property Administration on Aug. 5, 2021 and entitled “DISPLAY PANEL AND METHOD FOR MANUFACTURING SAME”, which is incorporated herein by reference in its entirety.

FIELD OF INVENTION

The present disclosure relates to display technologies, and more particularly, to a display panel and a method for manufacturing a display panel.

BACKGROUND OF INVENTION

In recent years, smartphones have entered a “full-screen” era, and the pursuit of an ultimate high screen-to-body ratio has become a new development trend. Therefore, a camera under panel (CUP) technology emerges. In the CUP technology, a camera is disposed below a screen, and this region is referred to as a CUP region. This technology can provide a CUP function while achieving full-screen display, and is an ultimate solution for full screen phones.

In a screen using the CUP technology, the display region may be divided into a CUP region and a normal display region. The two regions have different structural designs and pixel designs. However, in the conventional technologies, because the CUP region and the normal display region have different structural designs, the two regions have different circuit traces and processes, and further electrical properties of a driving device located in the CUP region are different from those of the normal display region. As a result, non-uniform display occurs in the CUP region.

Therefore, there is an urgent need to improve the electrical properties of the driving device in the CUP region, to improve the electrical uniformity between the CUP region and the normal display region, thereby alleviating the non-uniform display.

SUMMARY OF INVENTION

In the conventional technologies, because the CUP region and the normal display region have different structural designs, the two regions have different circuit traces and processes, and further electrical properties of a driving device located in the CUP region are different from those of the normal display region. As a result, non-uniform display occurs in the CUP region.

An objective of the present disclosure is to provide a display panel and a preparation method thereof, to resolve a technical problem in the prior art of non-uniform display in a camera under panel (CUP) region because electrical properties of a driving device located in the CUP region are different from those of a normal display region.

To resolve the above problem, the present disclosure provides a display panel, wherein a first display region and a second display region are defined on the display panel, and the display panel includes: a substrate; a driving device layer, disposed on the substrate and including a plurality of thin film transistors (TFTs); and a light-emitting device layer, disposed on the driving device layer and including a plurality of light-emitting subpixels arranged in an array.wherein in the second display region, the driving device layer is further provided with a dummy through hole located within an orthographic projection range of at least one of the light-emitting subpixels on the substrate, and the dummy through hole and the at least one light-emitting subpixel are insulated from each other.

In some embodiments, in the second display region, the TFT is disposed at an edge of the second display region close to the first display region.

In some embodiments, the TFT is disposed at a same layer with the dummy through hole.

In some embodiments, the TFT includes: an active layer, disposed on the substrate; a first insulating layer, covering the active layer; a first metal layer, disposed on the first insulating layer; a second insulating layer, disposed on the first metal layer; and a second metal layer, disposed on the second insulating layer and patterned to form a source and a drain, wherein the source and the drain are electrically connected to the active layer respectively through a first through hole and a second through hole that runs through the first insulating layer and the second insulating layer,wherein the dummy through hole is disposed at a same layer with the first through hole and the second through hole.

In some embodiments, a quantity of the dummy through holes located within the orthographic projection range of the at least one light-emitting subpixel on the substrate is greater than or equal to 1.

In some embodiments, a shape of the dummy through hole includes at least one of a rectangle or a circle.

In some embodiments, the light-emitting subpixels have different sizes, and the quantity of dummy through holes is proportional to the sizes of the light-emitting subpixels.

In some embodiments, in the first display region, the driving device layer is provided with a plurality of through holes corresponding to the light-emitting subpixels, and the through holes are electrically connected to the light-emitting subpixels,wherein a density of the dummy through holes in the second display region is equal to a density of the through holes in the first display region.

In some embodiments, the display panel further includes an organic planarization layer, wherein the organic planarization layer is disposed between the driving device layer and the light-emitting device layer, and the organic planarization layer fills the dummy through hole that runs through the first insulating layer and the second insulating layer.

The present disclosure further provides a method for manufacturing a display panel, wherein a first display region and a second display region are defined on the display panel, and the preparation method includes steps of:providing a substrate; forming a driving device layer on the substrate, wherein the driving device layer includes a plurality of TFTs; and forming a light-emitting device layer on the driving device layer, wherein the light-emitting device layer includes a plurality of light-emitting subpixels arranged in an array,wherein in the second display region, the driving device layer is further provided with a dummy through hole located within an orthographic projection range of each of the light-emitting subpixels on the substrate, and the dummy through hole and the light-emitting subpixels are insulated from each other.

The present disclosure further provides a method for manufacturing a display panel, wherein a first display region and a second display region are defined on the display panel, and the preparation method includes steps of:providing a substrate; forming a driving device layer on the substrate, wherein the driving device layer includes a plurality of thin film transistors (TFTs); and forming a light-emitting device layer on the driving device layer, wherein the light-emitting device layer includes a plurality of light-emitting subpixels arranged in an array,wherein in the second display region, the driving device layer is further provided with a dummy through hole located within an orthographic projection range of at least one of the light-emitting subpixels on the substrate, and the dummy through hole and the at least one light-emitting subpixel are insulated from each other.

In some embodiments, in the second display region, the TFT is disposed at an edge of the second display region close to the first display region.

In some embodiments, the TFT is disposed at a same layer with the dummy through hole.

In some embodiments, the step of forming the driving device layer on the substrate includes: sequentially disposing an active layer, a first insulating layer, a first metal layer, a second insulating layer, and a second metal layer on the substrate, wherein the second metal layer is patterned to form a source and a drain; and providing a first through hole and a second through hole that run through the first insulating layer and the second insulating layer and the dummy through hole located in the second display region,wherein the source and the drain are electrically connected to the active layer respectively through the first through hole and the second through hole.

In some embodiments, the step of forming the driving device layer on the substrate further includes: forming an organic planarization layer on the second metal layer.

In some embodiments, a quantity of the dummy through holes located within the orthographic projection range of the at least one light-emitting subpixel on the substrate is greater than or equal to 1.

In some embodiments, the light-emitting subpixels have different sizes, and the quantity of dummy through holes is proportional to the sizes of the light-emitting subpixels.

In some embodiments, in the first display region, the driving device layer is provided with a plurality of through holes corresponding to the light-emitting subpixels, and the through holes are electrically connected to the light-emitting subpixels,wherein a density of the dummy through holes in the second display region is equal to a density of the through holes in the first display region.

In some embodiments, the organic planarization layer fills the dummy through hole that runs through the first insulating layer and the second insulating layer.

In some embodiments, the dummy through hole is filled with a non-conductive material.

In the display panel and the preparation method thereof in the present disclosure, a dummy through hole located within an orthographic projection range of at least one of the light-emitting subpixels on the substrate is disposed in the second display region, and the dummy through hole and the at least one light-emitting subpixel are insulated from each other.

Provided with the dummy through hole, the driving device layer may also have a uniform hole-opening density in the second display region, to uniformly remove impurity elements, such as hydrogen in an annealing process, and the electrical uniformity between the TFTs in the second display region is ensured, thereby alleviating non-uniform display.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In the description of the present disclosure, it should be understood that orientation or position relationships indicated by the terms, such as “center”, “longitudinal”, “transverse”, “length”, “width”, “thickness”, “on”, “below”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, and “anticlockwise” are based on orientation or position relationships shown in the accompanying drawings, and are used only for ease and brevity of illustration and description, rather than indicating or implying that the mentioned apparatus or component need to have a particular orientation or need to be constructed and operated in a particular orientation. Therefore, such terms should not be construed as a limitation on the present disclosure. In addition, the terms “first” and “second” are used for the purpose of description only, and should not be understood as indicating or implying relative importance or implicitly indicating a quantity of indicated technical features. Therefore, a feature restricted by “first” or “second” may explicitly indicate or implicitly include one or more such features. In the descriptions of the present disclosure, “a plurality of” means two or more, unless otherwise definitely and specifically limited.

Many different implementations or examples are provided below to implement different structures of the present disclosure. To simplify the disclosure of the present disclosure, the following describes components and settings of particular examples. Certainly, the components and settings are merely examples, and are not intended to limit the present disclosure. In addition, in the present disclosure, reference numbers and/or reference letters may be repeated in different examples. Such repetition is intended to simplify and clarify the present disclosure, and does not indicate a relationship between various implementations and/or settings that are discussed. In addition, the present disclosure provides examples of various specific processes and materials, but a person skilled in the art may be aware of the applicability of another process and/or the use of another material.

The technical solutions of the present disclosure are described now with reference to specific embodiments.

As shown inFIGS.1and2, the present disclosure provides a display panel100, and more specifically, an organic light-emitting diode (OLED) display panel. A first display region AA and a second display region TA are defined on the display panel100. In the present embodiment of the present disclosure, the first display region AA may be a normal display region, and the second display region TA may be a camera under panel (CUP) region. The second display region TA of the CUP region has a large-area transparent region, to provide sufficient light transmittance for a camera to photograph an image in a photographing mode state.

In an embodiment, the display panel100includes a substrate10, a driving device layer3, and a light-emitting device layer60.

The substrate10may be a glass substrate or a flexible substrate, which is not particularly limited in the present disclosure.

The driving device layer3is disposed on the substrate10and includes a plurality of thin film transistors (TFTs)30; and the light-emitting device layer60is disposed on the driving device layer3and includes a plurality of light-emitting subpixels605arranged in an array.

Further, the display panel100is further provided with a buffer layer20between the driving device layer3and the substrate10.

In the second display region TA, the driving device layer3is further provided with a dummy through hole103located within an orthographic projection range of at least one of the light-emitting subpixels605on the substrate10, and the dummy through hole103and the at least one light-emitting subpixel605are insulated from each other.

Generally, in the art, a through hole is provided and is filled with a conductive material, so that an upper-layer metal layer and a lower-layer metal layer may be electrically connected, to conduct an electronic component. However, the dummy through hole in the present disclosure is filled with a non-conductive material, and further has a characteristic of insulating from the electronic component.

The non-conductive material may include an organic planarization layer material, and the organic planarization layer material has excellent flatness and light transmittance.

Therefore, provided with the dummy through hole103, the driving device layer3may also have a uniform hole-opening density in the second display region TA while maintaining flatness and a large-area transparent region, to uniformly remove impurity elements, such as hydrogen in an annealing process, and electrical uniformity between the TFTs30in the second display region TA is ensured, thereby alleviating non-uniform display of the display panel100. In addition, the dummy through hole103and the at least one light-emitting subpixel605are insulated from each other, so that the dummy through hole103cannot affect the display effect of the second display region TA while improving the electrical properties of the second display region TA.

Preferably, the dummy through hole103is located within an orthographic projection range of each of the light-emitting subpixels605on the substrate10to make the hole-opening density more uniform.

In an embodiment of the present disclosure, a plurality of dummy through holes103may have a same size or different sizes, as long as the second display region TA has a uniform hole-opening density.

Further, in the second display region TA, the TFTs30are disposed at an edge of the second display region TA close to the first display region AA. It may be understood that, in the second display region TA, the TFTs30are disposed at the edge of the second display region TA close to the first display region AA, so that the TFTs30and lines (such as gate lines or data lines) connecting the TFTs30may occupy only a small part of an area of the second display region TA, and furthermore the second display region TA may further have a larger-area transparent region, to provide sufficient light transmittance for a camera to photograph an image in a photographing mode state.

In an embodiment of the present disclosure, the TFT30is disposed at a same layer with the dummy through hole103.

Further, in the first display region AA, the driving device layer3is provided with a plurality of through holes corresponding to the light-emitting subpixels605, and the through holes are electrically connected to the light-emitting subpixels605,wherein a density of the dummy through holes103in the second display region TA is equal to a density of the through holes in the first display region AA.

Specifically, the TFT30includes an active layer301, a first insulating layer302, a first metal layer303, a second insulating layer306, and a second metal layer307. The active layer301is disposed on the substrate10; the first insulating layer302covers the active layer301; the first metal layer303is disposed on the first insulating layer302to form a first gate; the second insulating layer306is disposed on the first metal layer303; and the second metal layer307is disposed on the second insulating layer306and is patterned to form a source3071and a drain3072, wherein the source3071and the drain3072are electrically connected to the active layer301respectively through a first through hole101and a second through hole102that runs through the first insulating layer302and the second insulating layer306. In the first display region AA, the through holes corresponding to the light-emitting subpixels605includes the first through hole101and the second through hole102.

The dummy through hole103is disposed at a same layer with the first through hole101and the second through hole102. The dummy through hole103is disposed at the same layer with the first through hole101and the second through hole102, so that the dummy through hole103may be simultaneously formed with the first through hole101and the second through hole102in a same hole-opening process without an additional hole-opening process, and further no additional preparation process is required when the dummy through hole103is formed. Therefore, the preparation procedure can be simplified and the preparation costs can be reduced.

In addition, in the present disclosure, a density of the dummy through holes103in the second display region TA is set to be equal to a density of the through holes in the first display region AA, thereby also ensuring that the first display region AA and the second display region TA have a uniform hole-opening density while ensuring that the second display region TA has a uniform hole-opening density, and further improving the overall display uniformity of the display panel100.

In another embodiment of the present disclosure, the TFT30further includes a third insulating layer304and a third metal layer305. The third insulating layer304is disposed between the first insulating layer302and the second insulating layer306and covers the first metal layer303. The third metal layer305is disposed on the third insulating layer304and is covered by the second insulating layer306. The third metal layer305is formed with a second gate, and the second gate and the first gate may form a capacitance to further prevent electric leakage of the TFT30.

In the present embodiment, the source3071and the drain3072are electrically connected to the active layer301respectively through the first through hole101and the second through hole102that run through the first insulating layer302, the third insulating layer304, and the second insulating layer306. The dummy through hole103may also be formed by running through the first insulating layer302, the third insulating layer304, and the second insulating layer306, so that the dummy through hole103may be simultaneously formed with the first through hole101and the second through hole102in a same hole-opening process without an additional hole-opening process, and further no additional preparation process is required when the dummy through hole103is formed. Therefore, the preparation procedure can be simplified and the preparation costs can be reduced.

Further, the display panel100further includes an organic planarization layer40, and the organic planarization layer40is disposed between the driving device layer3and the light-emitting device layer60. The dummy through hole103may be directly filled with the organic planarization layer40. The additional preparation process can be omitted by directly filling the dummy through hole103with the organic planarization layer40, and therefore the preparation procedure can be simplified and the preparation costs can be reduced.

It may be understood that, the driving device layer3includes the active layer301, the first insulating layer302, the first metal layer303, the second insulating layer306, the second metal layer307, the third insulating layer304, and the third metal layer305. The first insulating layer302, the third insulating layer304, and the second insulating layer306may be inorganic insulating layers, and the second insulating layer306may be used for improving stress and supplementing a hydrogen source, to further make up TFT channel defects and improve the electrical properties.

Further, the display panel100further includes a transparent metal layer50. The transparent metal layer50is disposed between the organic planarization layer40and the light-emitting device layer60, and is electrically connected to the drain3072through the third through hole104that runs through the organic planarization layer40. The transparent metal layer50may be made of indium tin oxide (ITO).

It should be noted that, in the second display region TA, the transparent metal layer50is patterned to form a transparent metal line501. The transparent metal line501extends from a position corresponding to a position below the light-emitting subpixels605to a position corresponding to a position above the TFTs30at the edge of the second display region TA, and the TFTs30are electrically connected to the light-emitting subpixels605through the transparent metal line501.

In the second display region TA, in the present disclosure, the transparent metal line501is electrically connected to the light-emitting subpixels605and the TFTs30located at the edge of the second display region TA, so that an electrical connection between the light-emitting subpixels605and the TFTs30is implemented, and the second display region TA further maintains a larger-area transparent region, to provide sufficient light transmittance for a camera to photograph an image in a photographing mode state.

In another embodiment, the organic planarization layer40includes a first organic planarization layer41and a second organic planarization layer42. The second organic planarization layer42is disposed on the second insulating layer306, the first organic planarization layer41is disposed on the second organic planarization layer42, and the display panel100further includes a fourth metal layer80disposed between the first organic planarization layer41and the second organic planarization layer42. The fourth metal layer80may be made of indium zinc oxide (IZO).

In the present embodiment, the fourth metal layer80is electrically connected to the transparent metal layer50and the drain3072. Specifically, the transparent metal layer50is electrically connected to the fourth metal layer80through the third through hole104, and the fourth metal layer80is electrically connected to the drain3072through the fourth through hole105. The fourth metal layer80is electrically connected to the transparent metal layer50and the drain3072to further reduce voltage drop and improve the display effect.

Further, the light-emitting device layer60may further include an anode601, a pixel definition layer602, a light-emitting material layer603, and a cathode604. The light-emitting subpixel605is located within a hole-opening region in which the pixel definition layer602is disposed and includes the anode601and the light-emitting material layer603, and the cathode604covers the light-emitting subpixel605and the pixel definition layer602. The anode601may be made of ITO/Ag/ITO. In the first display region AA, the light-emitting subpixel605includes a first red subpixel unit R1, a first green subpixel unit G1, and a first blue subpixel unit B1, wherein the first red subpixel unit R1is configured to emit red light, the first green subpixel unit G1is configured to emit green light, and the first blue subpixel unit B1is configured to emit blue light.

In the second display region TA, the light-emitting subpixel605includes a second red subpixel unit R2, a second green subpixel unit G2, and a second blue subpixel unit B2, wherein the second red subpixel unit R2is configured to emit red light, the second green subpixel unit G2is configured to emit green light, and the second blue subpixel unit B2is configured to emit blue light.

In an embodiment, as shown inFIG.3, in the first display region AA, the first red subpixel unit R1, the first green subpixel unit G1, and the first blue subpixel unit B1are all rectangular, a light-emitting area of the first blue subpixel unit B1is greater than light-emitting areas of the first red subpixel unit R1and the first green subpixel unit G1, and the light-emitting area of the first red subpixel unit R1is greater than the light-emitting area of the first green subpixel unit G1.

It should be noted that, shapes of the first red subpixel unit R1, the first green subpixel unit G1, and the first blue subpixel unit B1are not limited to rectangles, and may further be correspondingly set according to a shape of the first display region AA. In addition, because light-emitting efficiency of the first blue subpixel unit B1is poor but light-emitting efficiency of the first green subpixel unit G1is better, the light-emitting area of the first blue subpixel unit B1may be set to the largest, and the light-emitting area of the first green subpixel unit G1may be set to the smallest, so that the first red subpixel unit R1, the first green subpixel unit G1, and the first blue subpixel unit B1have more uniform luminance.

In the second display region TA, the second red subpixel unit R2, the second green subpixel unit G2, and the second blue subpixel unit B2are all circular, a light-emitting area of the second blue subpixel unit B2is greater than light-emitting areas of the second red subpixel unit R2and the second green subpixel unit G2, and the light-emitting area of the second red subpixel unit R2is greater than the light-emitting area of the second green subpixel unit G2.

It should be noted that, shapes of the second red subpixel unit R2, the second green subpixel unit G2, and the second blue subpixel unit B2are limited to circles, and therefore the areas of the second red subpixel unit R2, the second green subpixel unit G2, and the second blue subpixel unit B2are minimized to further increase the light transmittance, so that the second display region TA has a larger-area transparent region, to provide sufficient light transmittance for a camera to photograph an image in a photographing mode state. In addition, because light-emitting efficiency of the second blue subpixel unit B2is poor but light-emitting efficiency of the second green subpixel unit G2is better, the light-emitting area of the second blue subpixel unit B2may be set to the largest, and the light-emitting area of the second green subpixel unit G2may be set to the smallest, so that the second red subpixel unit R2, the second green subpixel unit G2, and the second blue subpixel unit B2have more uniform luminance.

For the shape and size design of the light-emitting subpixel605in the second display region TA and the design of the line for connecting the light-emitting subpixel and the TFT30, reference may be specifically made to related patent documents CN112103329A and CN112259596A, and details are not described herein again.

In an embodiment of the present disclosure, in the second display region TA, a quantity of the dummy through holes103located within the orthographic projection range of the at least one light-emitting subpixel605on the substrate10is greater than or equal to 1. A shape of the dummy through hole103includes at least one of a rectangle or a circle.

In an embodiment of the present disclosure, the light-emitting subpixels605have different sizes, and the quantity of the dummy through holes103is proportional to the sizes of the light-emitting subpixels605.

Specifically, the size of the second blue subpixel unit B2is greater that of the second red subpixel unit R2, and the size of the second red subpixel unit R2is greater than that of the second green subpixel unit G2. As shown inFIG.4, a quantity of dummy through holes103corresponding to the second red subpixel unit R2is 5, a quantity of dummy through holes103corresponding to the second green subpixel unit G2is 3, a quantity of dummy through holes103corresponding to the second blue subpixel unit B2is 7, and the shape of the dummy through hole103is a rectangle.

In the present disclosure, the quantity of the dummy through holes103is set to be proportional to the sizes of the light-emitting subpixels605, to further ensure that the second display region TA has a uniform hole-opening density.

In another embodiment of the present disclosure, as shown inFIG.5, a difference fromFIG.4is only in that the shape of the dummy through hole103is a circle.

In still another embodiment of the present disclosure, as shown inFIG.6, a difference fromFIG.4is only in that a quantity of dummy through holes103corresponding to the second red subpixel unit R2is 7, a quantity of dummy through holes103corresponding to the second green subpixel unit G2is 4, a quantity of dummy through holes103corresponding to the second blue subpixel unit B2is 10.

It may be understood that, the quantity of the dummy through holes103within the orthographic projection range of the at least one light-emitting subpixel605on the substrate10is not limited, and may be set according to a specific requirement, as long as it is ensured that the second display region TA has a uniform hole-opening density, to uniformly remove impurity elements, such as hydrogen in an annealing process. Therefore, the electrical uniformity between the TFTs30in the second display region TA can be ensured, thereby alleviating the non-uniform display of the display panel100.

In addition, the shapes of the dummy through hole103may include a rectangle or a circle, and may be set according to a specific requirement.

Further, the display panel100further includes a thin film encapsulation layer70, and the thin film encapsulation layer70is configured to isolate external water or oxygen, to prevent the display panel100from failing.

As shown inFIG.7, the present disclosure further provides a method for manufacturing a display panel100. The preparation method includes the following steps:S10. Provide a substrate10.S20. Form a driving device layer3on the substrate10, wherein the driving device layer3includes a plurality of TFTs30.S30. Form a light-emitting device layer60on the driving device layer3, wherein the light-emitting device layer60includes a plurality of light-emitting subpixels605arranged in an array, wherein in the second display region TA, the driving device layer3is further provided with a dummy through hole103located within an orthographic projection range of at least one of the light-emitting subpixels605on the substrate10, and the dummy through hole103and the at least one light-emitting subpixel605are insulated from each other.

Generally, in the art, a through hole is provided and is filled with a conductive material, so that an upper-layer metal layer and a lower-layer metal layer may be electrically connected, to conduct an electronic component. However, the dummy through hole in the present disclosure is filled with a non-conductive material, and further has a characteristic of insulating from the electronic component.

The non-conductive material may include an organic planarization layer material, and the organic planarization layer material has excellent flatness and light transmittance.

In the method for manufacturing the display panel according to the present disclosure, provided with the dummy through hole103, the driving device layer3may also have a uniform hole-opening density in the second display region TA while maintaining flatness and a large-area transparent region, to uniformly remove impurity elements, such as hydrogen in an annealing process, and electrical uniformity between the TFTs30in the second display region TA is ensured, thereby alleviating non-uniform display of the display panel100. In addition, the dummy through hole103and the at least one light-emitting subpixel605are insulated from each other, so that the dummy through hole103cannot affect the display effect of the second display region TA while improving the electrical properties of the second display region TA.

The preparation method further includes S11: forming a buffer layer20on the substrate10.

The step S20further includes the following steps:S201. Sequentially dispose an active layer301, a first insulating layer302, a first metal layer303, a third insulating layer304, a third metal layer305, and a second insulating layer306on the buffer layer20.S202. Provide a first through hole101, a second through hole102, and a dummy through hole103located in the second display region TA that run through the first insulating layer302, the third insulating layer304, and the second insulating layer306.S203. Form a second metal layer307on the second insulating layer306, wherein the second metal layer307is patterned to form a source3071and a drain3072, and the source3071and the drain3072are electrically connected to the active layer301respectively through the first through hole101and the second through hole102.

Therefore, the dummy through hole103may be simultaneously formed with the first through hole101and the second through hole102in a same hole-opening process without an additional hole-opening process, and further no additional preparation process is required when the dummy through hole103is formed. Therefore, the preparation procedure can be simplified and the preparation costs can be reduced.

After step S203, the preparation method further includes S21: forming an organic planarization layer40on the second metal layer307.

The dummy through hole103may be directly filled with the organic planarization layer40. The additional preparation process can be omitted by directly filling the dummy through hole103with the organic planarization layer40, and therefore the preparation procedure can be simplified and the preparation costs can be reduced.

After step S21, the preparation method further includes S22: forming a transparent metal layer50on the organic planarization layer40, wherein in the second display region TA, the transparent metal layer50is patterned to form a transparent metal line501. The transparent metal line501extends from a position corresponding to a position below the light-emitting subpixels605to a position corresponding to a position above the TFTs30at the edge of the second display region TA, and the TFTs30are electrically connected to the light-emitting subpixels605through the transparent metal line501.

In the second display region TA, in the present disclosure, the transparent metal line501is electrically connected to the light-emitting subpixels605and the TFTs30located at the edge of the second display region TA, so that an electrical connection between the light-emitting subpixels605and the TFTs30is implemented, and the second display region TA further maintains a larger-area transparent region, to provide sufficient light transmittance for a camera to photograph an image in a photographing mode state.

After step S30, the preparation method further includes S40: forming a thin film encapsulation layer70on the light-emitting device layer60.

For a detailed description of each layer, refer to the above display panel100, and details are not described in this preparation method again.

In the above embodiment, the descriptions of the embodiments have respective focuses, and for a part that is not described in detail in one embodiment, reference may be made to the related descriptions of other embodiments.

The embodiments of the present disclosure are described above in detail. Although the principles and implementations of the present disclosure are described using specific examples in this specification, the descriptions of the above embodiments are merely intended to help understand the technical solutions and the core idea of the present disclosure. It should be understood by persons of ordinary skill in the art that modifications can be made to the technical solutions recorded in the above embodiments, or equivalent replacements can be made to some technical features in the technical solutions, as long as such modifications or replacements do not cause the essence of corresponding technical solutions to depart from the scope of the technical solutions of the embodiments of the present disclosure.