阅读说明：本技术 顶发射oled显示背板及其制作方法和oled显示装置 (Top-emitting OLED display back plate, manufacturing method thereof and OLED display device ) 是由 张扬 周斌 程磊磊 王庆贺 刘军 王超 张晓东 于 2019-11-18 设计创作，主要内容包括：本发明提供了一种顶发射OLED显示背板及其制作方法和OLED显示装置。顶发射OLED显示背板包括：衬底基板，衬底基板中设有源极和漏极；平坦层，平坦层设置在衬底基板的表面上；金属反射层，金属反射层设置在平坦层远离衬底基板的一侧，其中，平坦层和金属反射层中具有贯穿平坦层和金属反射层的通孔，且通孔暴露出源极或漏极；阳极，阳极设置在金属反射层远离衬底基板的一侧，且通过通孔与源极或漏极电连接。阳极直接通过通孔与源极或漏极电连接，而不是通过金属反射层与源极或漏极间电连接，如此可以避免在制作中因金属反射层在通孔侧壁出现断线裂缝等现象而导致阳极与源极或漏极之间接触不良的现象，从而提升显示面板的质量和显示效果。(The invention provides a top-emitting OLED display back plate, a manufacturing method thereof and an OLED display device. The top-emitting OLED display backplane includes: the substrate base plate is provided with a source electrode and a drain electrode; a planarization layer disposed on a surface of the base substrate; the metal reflecting layer is arranged on one side of the flat layer, which is far away from the substrate, wherein the flat layer and the metal reflecting layer are provided with through holes which penetrate through the flat layer and the metal reflecting layer, and the source electrode or the drain electrode is exposed out of the through holes; and the anode is arranged on one side of the metal reflecting layer, which is far away from the substrate base plate, and is electrically connected with the source electrode or the drain electrode through the through hole. The anode is directly electrically connected with the source electrode or the drain electrode through the through hole instead of being electrically connected with the source electrode or the drain electrode through the metal reflecting layer, so that the phenomenon of poor contact between the anode and the source electrode or the drain electrode due to the phenomena of line breaking, cracking and the like of the metal reflecting layer on the side wall of the through hole in the manufacturing process can be avoided, and the quality and the display effect of the display panel are improved.)

1. A top-emitting OLED display backplane, comprising:

the substrate comprises a substrate base plate, wherein a source electrode and a drain electrode are arranged in the substrate base plate;

a planar layer disposed on a surface of the base substrate;

the metal reflecting layer is arranged on one side, far away from the substrate base plate, of the flat layer, a through hole penetrating through the flat layer and the metal reflecting layer is formed in the flat layer and the metal reflecting layer, and the source electrode or the drain electrode is exposed out of the through hole;

the anode is arranged on one side, far away from the substrate base plate, of the metal reflection layer and is electrically connected with the source electrode or the drain electrode through the through hole.

2. The top-emitting OLED display backplane according to claim 1, wherein said planar layer comprises:

an inorganic planarization layer disposed on a surface of the base substrate;

a silicone planarization layer disposed on a surface of the inorganic planarization layer distal from the substrate base plate.

3. The top-emitting OLED display backplane according to claim 1 or 2, wherein the material of the metal reflective layer comprises at least one of molybdenum, aluminum, molybdenum alloy, aluminum alloy, and molybdenum aluminum alloy.

4. The top-emitting OLED display backplane according to claim 1 or 2, wherein the outer edge face of the anode does not extend beyond the outer edge face of the metallic reflective layer or the anode covers the outer edge face of the metallic reflective layer.

5. A method of making the top-emitting OLED display backplane of any of claims 1-4, comprising:

providing a substrate, wherein a source electrode and a drain electrode are arranged in the substrate;

sequentially forming an insulating layer and a metal layer on the surface of the substrate, wherein the insulating layer covers the source electrode and the drain electrode;

patterning the metal layer and the insulating layer to obtain a metal reflecting layer, a flat layer and a through hole penetrating through the metal reflecting layer and the flat layer, wherein the through hole exposes the source electrode or the drain electrode;

and forming an anode on one side of the metal reflecting layer far away from the substrate base plate, wherein the anode is electrically connected with the source electrode or the drain electrode through the through hole.

6. The method of claim 5, wherein the patterning process comprises:

forming a first photoresist layer with a first opening on the surface of the metal layer far away from the substrate base plate;

etching and removing the metal layer exposed by the first opening and the insulating layer corresponding to the first opening so as to obtain the through hole and the flat layer;

removing part of the first photoresist layer to obtain a second photoresist layer, wherein the orthographic projection of the second photoresist layer on the substrate is approximately overlapped with the orthographic projection of the light emitting layer on the substrate;

and etching and removing the metal layer exposed by the second photoresist layer so as to obtain the metal reflecting layer.

7. The method of claim 5, wherein the steps of patterning and forming the anode comprise:

forming a third photoresist layer with a second opening on the surface of the metal layer far away from the substrate base plate;

etching and removing the metal layer exposed by the second opening and the insulating layer corresponding to the second opening so as to obtain the through hole and the flat layer;

removing the third photoresist layer;

forming a transparent electrode layer on one side of the etched metal layer, which is far away from the substrate base plate, wherein the transparent electrode layer covers the surface of the metal layer and the inner wall of the through hole;

and forming a fourth photoresist layer on the surface of the transparent electrode layer far away from the substrate base plate, wherein the orthographic projection of the fourth photoresist layer on the substrate base plate is approximately overlapped with the sum of the orthographic projection of the light emitting layer on the substrate base plate and the orthographic projection of the through hole on the substrate base plate, and etching and removing the transparent electrode layer and the metal layer exposed by the fourth photoresist layer so as to obtain the anode and the metal reflecting layer.

8. The method of claim 7, wherein the step of etching away the transparent electrode layer and the metal layer exposed by the fourth photoresist layer comprises:

removing the transparent electrode layer exposed by the fourth photoresist layer by using first etching liquid so as to obtain the anode, wherein the first etching liquid does not react with the metal layer;

and removing the metal layer which is not covered by the anode by using a second etching liquid so as to obtain the metal reflecting layer.

9. The method according to any one of claims 5 to 8, wherein the step of forming the insulating layer comprises:

forming an inorganic insulating layer disposed on a surface of the base substrate;

forming an organic silicon insulating layer, wherein the organic silicon insulating layer is arranged on the surface of the inorganic insulating layer far away from the substrate base plate.

10. An OLED display device comprising the top-emitting OLED display backplane of any of claims 1-4.

Technical Field

The invention relates to the technical field of display, in particular to a top-emitting OLED display back plate, a manufacturing method thereof and an OLED display device.

Background

Recently, large-sized OLEDs have become mainstream in the display industry due to their advantages of high contrast, self-luminescence, etc., and top-emitting OLEDs have become important in the development due to their large aperture ratio. The top emission OLED is classified into an evaporation type OLED, which emits light by evaporating an organic Electroluminescent (EL) light emitting material over a reflective anode, and a printing type OLED, which emits light by printing a self-light emitting material as a light source. In order to achieve a better display effect, the OLED needs to be prepared on a flat layer with better flatness, especially the OLED is printed, the requirement on flatness is very high, so that the flat layer with a certain thickness needs to be formed before the OLED is formed, then, holes are dug in the flat layer, and the anode of the OLED is electrically connected with the thin film transistor through the through holes, but poor contact often occurs in the through holes, so that the display quality is affected.

Therefore, research on the OLED display back sheet is awaited.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. Therefore, an object of the present invention is to provide a top-emitting OLED display backplane with good circuit contact or good display effect.

In one aspect of the invention, the invention provides a top-emitting OLED display backplane. According to an embodiment of the present invention, a top-emitting OLED display backplane comprises: the substrate comprises a substrate base plate, wherein a source electrode and a drain electrode are arranged in the substrate base plate; a planar layer disposed on a surface of the base substrate; the metal reflecting layer is arranged on one side, far away from the substrate base plate, of the flat layer, a through hole penetrating through the flat layer and the metal reflecting layer is formed in the flat layer and the metal reflecting layer, and the source electrode or the drain electrode is exposed out of the through hole; the anode is arranged on one side, far away from the substrate base plate, of the metal reflection layer and is electrically connected with the source electrode or the drain electrode through the through hole. Therefore, the anode is directly electrically connected with the source electrode or the drain electrode of the thin film transistor through the through hole instead of being electrically connected with the source electrode or the drain electrode through the metal reflecting layer, so that the phenomenon of poor contact between the anode and the source electrode or the drain electrode due to the phenomenon of line breaking, cracking and the like of the metal reflecting layer on the side wall of the through hole in the manufacturing process can be avoided, and the quality and the display effect of the display panel are improved.

According to an embodiment of the invention, the planarization layer comprises: an inorganic planarization layer disposed on a surface of the base substrate; a silicone planarization layer disposed on a surface of the inorganic planarization layer distal from the substrate base plate.

According to an embodiment of the present invention, a material of the metal reflective layer includes at least one of molybdenum, aluminum, a molybdenum alloy, an aluminum alloy, and a molybdenum-aluminum alloy.

According to an embodiment of the invention, the outer edge face of the anode does not extend beyond the outer edge face of the metallic reflective layer, or the anode covers the outer edge face of the metallic reflective layer.

In another aspect of the invention, the invention provides a method of making the aforementioned top-emitting OLED display backplane. According to an embodiment of the invention, a method of fabricating a top-emitting OLED display backplane includes: providing a substrate, wherein a source electrode and a drain electrode are arranged in the substrate; sequentially forming an insulating layer and a metal layer on the surface of the substrate, wherein the insulating layer covers the source electrode and the drain electrode; patterning the metal layer and the insulating layer to obtain a metal reflecting layer, a flat layer and a through hole penetrating through the metal reflecting layer and the flat layer, wherein the through hole exposes the source electrode or the drain electrode; and forming an anode on one side of the metal reflecting layer far away from the substrate base plate, wherein the anode is electrically connected with the source electrode or the drain electrode through the through hole. Therefore, in the manufacturing method, the metal layer at the through hole needs to be partially removed to obtain the reflecting layer, and the anode is directly contacted with the source electrode or the drain electrode exposed by the through hole to realize electric connection, namely, the reflecting layer does not exist in the through hole, so that the phenomenon of poor contact between the anode and the source electrode or the drain electrode due to the phenomenon of line breaking and cracking of the reflecting layer on the side wall of the through hole in the manufacturing process can be avoided, and the quality and the display effect of the display panel are improved; moreover, the manufacturing method is simple and easy to implement, is convenient for industrial mass production, and has high product yield.

According to an embodiment of the present invention, the patterning process includes: forming a first photoresist layer with a first opening on the surface of the metal layer far away from the substrate base plate; etching and removing the metal layer exposed by the first opening and the insulating layer corresponding to the first opening so as to obtain the through hole and the flat layer; removing part of the first photoresist layer to obtain a second photoresist layer, wherein the orthographic projection of the second photoresist layer on the substrate is approximately overlapped with the orthographic projection of the light emitting layer on the substrate; and etching and removing the metal layer exposed by the second photoresist layer so as to obtain the metal reflecting layer.

According to an embodiment of the invention, the steps of patterning and forming the anode comprise: forming a third photoresist layer with a second opening on the surface of the metal layer far away from the substrate base plate; etching and removing the metal layer exposed by the second opening and the insulating layer corresponding to the second opening so as to obtain the through hole and the flat layer; removing the third photoresist layer; forming a transparent electrode layer on one side of the etched metal layer, which is far away from the substrate base plate, wherein the transparent electrode layer covers the surface of the metal layer and the inner wall of the through hole; and forming a fourth photoresist layer on the surface of the transparent electrode layer far away from the substrate base plate, wherein the orthographic projection of the fourth photoresist layer on the substrate base plate is approximately overlapped with the sum of the orthographic projection of the light emitting layer on the substrate base plate and the orthographic projection of the through hole on the substrate base plate, and etching and removing the transparent electrode layer and the metal layer exposed by the fourth photoresist layer so as to obtain the anode and the metal reflecting layer.

According to the embodiment of the invention, the step of removing the transparent electrode layer and the metal layer exposed by the fourth photoresist layer by etching comprises the following steps: removing the transparent electrode layer exposed by the fourth photoresist layer by using first etching liquid so as to obtain the anode, wherein the first etching liquid does not react with the metal layer; and removing the metal layer which is not covered by the anode by using a second etching liquid so as to obtain the metal reflecting layer.

According to an embodiment of the present invention, the step of forming the insulating layer includes: forming an inorganic insulating layer, the inorganic flat layer being disposed on a surface of the base substrate; forming an organic silicon insulating layer, wherein the organic silicon insulating layer is arranged on the surface of the inorganic insulating layer far away from the substrate base plate.

In yet another aspect of the present invention, the present invention provides an OLED display device. According to an embodiment of the invention, the OLED display device comprises the aforementioned top-emitting OLED display backplane. Therefore, the OLED display device has good display effect and high yield. As will be understood by those skilled in the art, the OLED display device has all the features and advantages of the top-emitting OLED display backplane and the method for fabricating the same, and will not be described herein in any greater detail.

Drawings

FIG. 1 is a schematic structural diagram of an OLED display backplane according to an embodiment of the present invention.

FIG. 2 is a schematic structural diagram of an OLED display backplane according to another embodiment of the present invention.

FIG. 3 is a schematic structural diagram of an OLED display backplane according to another embodiment of the present invention.

FIG. 4 is a schematic structural diagram of an OLED display backplane with a chamfer.

FIG. 5 is a schematic structural diagram of an OLED display backplane according to yet another embodiment of the present invention.

FIG. 6 is a schematic structural diagram of an OLED display backplane according to yet another embodiment of the present invention.

FIG. 7 is a flow chart of a method for fabricating an OLED display backplane according to yet another embodiment of the present invention.

FIG. 8 is a schematic structural diagram of an OLED display backplane according to another embodiment of the present invention.

FIG. 9 is a schematic structural diagram of an OLED display backplane according to another embodiment of the present invention.

FIG. 10 is a schematic structural diagram of an OLED display backplane according to another embodiment of the present invention.

FIG. 11 is a schematic structural diagram of an OLED display backplane according to another embodiment of the present invention.

FIG. 12 is a schematic structural diagram of an OLED display backplane according to another embodiment of the present invention.

FIG. 13 is a schematic structural diagram of an OLED display backplane according to another embodiment of the present invention.

FIG. 14 is a schematic structural diagram of an OLED display backplane according to another embodiment of the present invention.

FIG. 15 is a schematic structural diagram of an OLED display backplane according to another embodiment of the present invention.

FIG. 16 is a schematic structural diagram of an OLED display backplane according to another embodiment of the present invention.

FIG. 17 is a schematic structural diagram of an OLED display backplane according to yet another embodiment of the present invention.

FIG. 18 is a schematic structural diagram of an OLED display backplane according to yet another embodiment of the present invention.

Detailed Description

The following describes embodiments of the present invention in detail. The following examples are illustrative only and are not to be construed as limiting the invention. The examples, where specific techniques or conditions are not indicated, are to be construed according to the techniques or conditions described in the literature in the art or according to the product specifications.

The present invention was obtained by the following recognition and study by the inventors:

in order to achieve better display effect, the flat layer is required to have very good flatness when the OLED display backplane is manufactured, so generally, after the inorganic flat layer (PVX) is deposited, an organic silicon flat layer (SOG) is continuously coated to improve the flatness thereof, then, the through hole is etched, then, the metal reflective layer is formed, and the metal reflective layer covers the inner wall of the through hole and is electrically connected with the source electrode or the drain electrode exposed by the through hole, and finally, the anode is formed on the surface of the metal reflective layer, that is, the anode is electrically connected with the source electrode or the drain electrode through the reflective layer. However, the inventors have unexpectedly found that when a via hole is etched in a flat layer (including PVX and SOG), the sidewall of the via hole is very steep (close to a right angle), and when a metal reflective layer is deposited, the reflective layer has poor climbing capability on the sidewall of the via hole, so that the metal reflective layer is very likely to have bad phenomena such as disconnection and cracking, and thus the anode formed on the surface of the metal reflective layer is also likely to have bad contact, cracking and the like, thereby affecting the display effect and the product quality. In view of the above technical problems, the inventor proposes after research that the metal reflective layer in the through hole can be removed, so that the anode with better climbing capability is electrically connected with the exposed source electrode or drain electrode of the through hole in a direct contact manner, and the defects caused by indirect electrical connection through the metal reflective layer are avoided, so that the product quality and the display effect can be effectively improved.

In view of the above, in one aspect of the invention, a top-emitting OLED display backplane is provided. According to an embodiment of the present invention, referring to fig. 1, a top-emitting OLED display backplane includes: a substrate 10, wherein a source electrode and a drain electrode 11 are arranged in the substrate 10; a flat layer 20, the flat layer 20 being disposed on a surface of the base substrate 10; a metal reflective layer 30, wherein the metal reflective layer 30 is disposed on a side of the planarization layer 20 away from the substrate 10, the planarization layer 20 and the metal reflective layer 30 have a through hole 23 penetrating through the planarization layer 20 and the metal reflective layer 30, and the through hole 23 exposes the source or the drain 11 (fig. 1 illustrates an example of exposing the drain); and an anode 40, wherein the anode 40 is arranged on one side of the metal reflecting layer 30 far away from the substrate base plate 10 and is electrically connected with the source electrode or the drain electrode 11 through the through hole 23. Therefore, the anode with better climbing capability is directly electrically connected with the source electrode or the drain electrode of the thin film transistor through the through hole instead of being electrically connected with the source electrode or the drain electrode through the metal reflecting layer, so that the phenomenon of poor contact between the anode and the source electrode or the drain electrode due to the phenomena of line breaking, cracking and the like of the metal reflecting layer on the side wall of the through hole in the manufacturing process can be avoided, and the quality and the display effect of the display panel are improved.

It should be noted that the substrate 10 includes a base 1 (such as a glass base or a flexible base), a buffer layer 2, a thin film transistor (including a gate 3, a source 7, a drain 11, and an active layer 5), a gate insulating layer 4, an interlayer dielectric layer 6, and a light shielding layer, and the arrangement position and connection requirements of the above structures are consistent with those of the prior art, and those skilled in the art may flexibly select the above structures according to actual requirements, in some embodiments, the schematic structure diagram of the above structures may refer to fig. 2, and those skilled in the art may understand that the arrangement manner between the above structures in the substrate 10 is not limited to fig. 2. In addition, the term "the through hole exposes the source electrode or the drain electrode" may refer to exposing the entire surface of the source electrode or the entire surface of the drain electrode, or may refer to exposing a portion of the surface of the source electrode or the surface of the drain electrode, as long as the anode and the source electrode or the drain electrode are electrically connected to each other effectively, thereby ensuring good display quality.

In the OLED display back plate, an OLED device comprises an anode, a hole injection layer, a light emitting layer, an electron transport layer, a cathode and other structures. It should be noted that, the metal reflective layer is disposed in the corresponding area of the light emitting layer, that is, the orthographic projection of the metal reflective layer on the substrate is approximately overlapped with the orthographic projection of the light emitting layer on the substrate (the size of the orthographic projection of the metal reflective layer on the substrate may be completely overlapped with the size of the orthographic projection of the light emitting layer on the substrate, or slightly different from the size of the orthographic projection of the light emitting layer on the substrate), for example, the orthographic projection of the metal reflective layer on the substrate is slightly larger than the orthographic projection of the light emitting layer on the substrate, and at this time, the orthographic projection of the metal reflective layer on the substrate covers the orthographic projection of the light emitting layer on the substrate, so.

In some embodiments, referring to fig. 3, the outer edge face 41 of the anode 40 does not extend beyond the outer edge face 31 of the metal reflective layer 30; in other embodiments, referring to fig. 1, the anode 40 covers the outer edge face 31 of the metal reflective layer 30. Therefore, in the position relation of the two anodes and the metal reflecting layer, the metal reflecting layer does not have a chamfer angle, and the connection quality of the circuit can be effectively ensured.

At present, when the metal reflective layer and the anode are prepared, the metal reflective layer and the anode are obtained by synchronously etching with the same etching solution, but in the etching, the etching rate of the metal reflective layer is usually greater than that of the anode, so that the obtained metal reflective layer 30 can form an inward-concave chamfer 1 (such as a dashed-line frame part in fig. 4), and thus poor line overlapping can be easily caused. And the requirement to metal reflecting layer and positive pole position relation in this application, the appearance of avoiding the chamfer that can be fine, and then the connection quality of promotion circuit.

According to an embodiment of the present invention, referring to fig. 5, the planarization layer 20 includes: an inorganic planarization layer 21, the inorganic planarization layer 21 being disposed on a surface of the base substrate 10; and the organic silicon flat layer 22, wherein the organic silicon flat layer 22 is arranged on the surface of the inorganic flat layer 21 far away from the substrate base plate 10. From this, further set up the organic silicon flat bed on inorganic flat bed, the flatness of promotion flat bed that can be better to better preparation OLED device guarantees to use this display panel who shows the backplate's display effect.

The material of the inorganic planarization layer is not limited, and can be flexibly selected by those skilled in the art according to the actual situation. In some embodiments, the material for forming the planarization layer includes, but is not limited to, silicon nitride, silicon oxide, silicon oxynitride, aluminum oxide, etc., so that not only the insulation property is better, but also the material source is wide and the cost is lower.

According to an embodiment of the present invention, the material of the metal reflective layer includes at least one of molybdenum (Mo), aluminum (Al), a molybdenum alloy, an aluminum alloy, and a molybdenum-aluminum alloy. Therefore, the material has good light reflectivity, is convenient to prepare and has low cost. If the reflective layer includes two materials, two metal reflective layers stacked one on another can be obtained by two depositions, for example, when the metal reflective layer includes molybdenum and aluminum, referring to fig. 6, the metal reflective layer 30 includes a molybdenum layer 31 and an aluminum layer 32, where the order of disposing the aluminum layer and the molybdenum layer has no specific requirement, the molybdenum layer 31 may be disposed on the side of the planar layer 20 away from the substrate 10, the aluminum layer 32 may be disposed on the side of the molybdenum layer 31 away from the substrate (as shown in fig. 6), the aluminum layer 32 may be disposed on the side of the planar layer 20 away from the substrate 10, and the molybdenum layer 31 may be disposed on the side of the aluminum layer 32 away from the substrate (not shown in the figure).

According to the embodiment of the present invention, the forming material of the anode is not particularly limited, and those skilled in the art can flexibly select the forming material according to the actual situation, for example, ITO (indium tin oxide) is used, so that the conductivity is good and the performance is good.

In another aspect of the invention, a method of making a top-emitting OLED display backplane is provided. According to an embodiment of the present invention, referring to fig. 7, a method of fabricating a top-emitting OLED display backplane includes:

s100: a substrate 10 is provided, a source and a drain 11 (the source is not shown in fig. 8) are provided in the substrate 10, and the structure schematic diagram refers to fig. 8.

S200: an insulating layer 200 and a metal layer 300 are sequentially formed on the surface of the substrate 10, and the insulating layer 200 covers the source (not shown) and the drain 11, and the structure diagram is shown in fig. 8.

In some embodiments, referring to fig. 8, the insulating layer 200 is formed to include an inorganic insulating layer 210 formed on a surface of the base substrate 10 and a silicone insulating layer 220 formed on a surface of the inorganic insulating layer 210 remote from the base substrate. Therefore, the flatness of the required flat layer can be improved better, so that an OLED device can be prepared better, and a good display effect is ensured. It will be understood by those skilled in the art that the insulating layer 200 covers the thin film transistor and the like, and thus the insulating layer covers the source and drain electrodes 11.

The method for fabricating the inorganic insulating layer includes, but is not limited to, chemical vapor deposition, physical vapor deposition, and the like, and the method for fabricating the organic silicon insulating layer includes, but is not limited to, coating (such as direct coating or spin coating). The method is mature in process and convenient for industrial production, and the prepared insulating layer is good in surface flatness and beneficial to obtaining of a flat layer with good flatness.

According to an embodiment of the present invention, the metal layer may include at least one layer, for example, a layer including an aluminum layer and a molybdenum layer, and during the manufacturing process, the molybdenum layer and the aluminum layer may be deposited in sequence on the surface of the insulating layer away from the substrate by a vapor chemical deposition or a sputtering deposition, so as to obtain a metal reflective layer with better light reflectivity.

S300: the metal layer 300 and the insulating layer 200 are patterned to obtain the metal reflective layer 30 and the planarization layer 20 and a via 23 penetrating the metal reflective layer 30 and the planarization layer 20, and the source or the drain 11 is exposed by the via 23, which is shown in fig. 9.

According to an embodiment of the present invention, the patterning process includes:

s310: a first photoresist layer 50 having a first opening 51 is formed on the surface of the metal layer 300 away from the substrate 10, and the structure diagram is shown in fig. 10. The first photoresist layer 50 may be formed by a halftone mask plate 60, and first, a complete photoresist layer is formed on the surface of the metal layer, the full light-transmitting region 63 of the halftone mask plate corresponds to the photoresist layer at the region where the through hole needs to be formed, the semi-light-transmitting region 62 corresponds to the photoresist layer at the non-light-emitting region except for the through hole, the non-light-transmitting region 61 corresponds to the photoresist layer at the light-emitting region of the display backplane, then, different positions of the photoresist layer are exposed to different degrees by the halftone mask plate 60, and then, the first photoresist layer 50 having the first opening 51 is obtained by development.

S320: the metal layer 300 exposed by the first opening 51 and the insulating layer 200 corresponding to the first opening 51 are removed by etching, so as to obtain the via 23 and the planarization layer 20, and the structural schematic diagram refers to fig. 11. Therefore, after the metal layer exposed by the first opening is etched, the insulating layer corresponding to the through hole (namely the insulating layer corresponding to the first opening) is etched and removed to form the through hole and the flat layer, and the metal layer (used for forming the metal reflection layer) in the through hole can be removed.

The metal layer 300 exposed by the first opening 51 after being removed by etching may be wet etched, and the insulating layer 200 corresponding to the first opening 51 after being removed by etching may be dry etched, so that the metal layer and the insulating layer corresponding to the first opening may be effectively removed.

S330: a portion of the first photoresist layer 50 is removed to obtain a second photoresist layer 52, and an orthogonal projection of the second photoresist layer 52 on the base substrate 10 substantially overlaps an orthogonal projection of the light emitting layer (not shown) on the base substrate, and the schematic structural diagram refers to fig. 12. The light-emitting layer refers to the light-emitting layer structure in the OLED device, wherein an orthogonal projection of the metal reflective layer to be prepared on the substrate substantially overlaps with an orthogonal projection of the light-emitting layer on the substrate.

S340: the metal layer 300 exposed by the second photoresist layer 52 (i.e. the metal layer 300 that has been etched once) is etched to obtain the metal reflective layer 30, and the structural diagram refers to fig. 12. Therefore, before the anode is formed, the metal reflecting layer is formed by etching, and the metal reflecting layer and the anode can be prevented from being synchronously etched and patterned, so that the phenomenon of chamfering (Tip) caused by different etching rates of the anode and the metal layer (the etching rate of the metal layer is greater than that of the anode material) is prevented, and the condition of poor circuit lap joint is prevented.

At present, when a metal reflective layer and an anode are prepared, a transparent electrode layer (for forming the anode) and a metal layer are etched synchronously by using the same etching solution to obtain the anode 40 and the reflective layer 30, but in the etching process, the etching rate of the metal layer is usually greater than that of the transparent electrode layer, so that the obtained reflective layer 30 forms an inward-concave chamfer 1 (such as a dashed frame part in fig. 4), and thus poor circuit overlapping is easily caused. In the application, the metal reflecting layer and the anode are obtained by step-by-step etching, and the problem of etching rate difference does not exist, so that the occurrence of chamfering can be well avoided, and the connection quality of a circuit is improved.

S400: an anode 40 is formed on a side of the metal reflective layer 30 away from the substrate base plate 10, and the anode 40 is electrically connected to the source or drain 11 through the via 23, and the structural schematic diagrams refer to fig. 1 to 3 and fig. 5 to 6.

According to an embodiment of the present invention, referring to fig. 13, the step of forming the anode includes: a transparent electrode layer 400 is formed on the side of the metal reflective layer 30 away from the base substrate 10, and the transparent electrode layer 400 covers the surface of the planarization layer 20 not covered by the metal reflective layer 30 and the surface exposed by the through hole 23, and then the transparent electrode layer is patterned by etching, and the transparent electrode layer on the surface of the planarization layer is removed to obtain the anode 40.

The method for forming the transparent electrode layer has no special requirements, and a person skilled in the art can flexibly select a conventional preparation method according to actual conditions, and redundant description is omitted here.

In some embodiments of the present invention, the metal reflective layer is formed through steps S310 to S340 as described above, and then the anode is formed through step S400, i.e., the metal reflective layer and the anode are formed in steps.

In other embodiments of the present invention, the metal reflective layer and the anode may be formed alternately, that is, in the step of forming the metal reflective layer, the anode is formed simultaneously, specifically: the patterning and anode forming steps include:

s410: a second photoresist layer 70 having a second opening 71 is formed on the surface of the metal layer 300 away from the substrate 10, and the structural diagram is shown in fig. 14.

S420: the metal layer 300 exposed by the second opening 71 and the insulating layer 200 corresponding to the second opening 71 are removed by etching, so as to obtain the via 23 and the planarization layer 20, and the structural schematic diagram refers to fig. 15.

The metal layer 300 exposed by the second opening 71 can be removed by wet etching, and the insulating layer 200 corresponding to the second opening 71 can be removed by dry etching, so that the metal layer and the insulating layer corresponding to the second opening can be effectively removed.

S430: the third photoresist layer 70 is removed, and the structure diagram refers to fig. 15.

S440: a transparent electrode layer 400 is formed on the side of the metal layer 300 etched in step S420, which is away from the substrate 10, and the transparent electrode layer 400 covers the surface of the metal layer 300 and the inner wall of the through hole 23 (i.e., the sidewall of the through hole 23 and the surface of the source or drain 11 exposed by the through hole 23), and the structure diagram refers to fig. 16.

S450: forming a fourth photoresist layer 80 on the surface of the transparent electrode layer 500 far from the base substrate 10, wherein an orthogonal projection of the fourth photoresist layer 80 on the base substrate 10 approximately overlaps with a sum of an orthogonal projection of the light emitting layer on the base substrate 10 and an orthogonal projection of the through hole 23 on the base substrate 10 (i.e. the fourth photoresist layer 80 covers the transparent electrode layer 400 corresponding to the light emitting layer and the transparent electrode layer 400 at the through hole 23), and etching and removing the transparent electrode layer 400 and the metal layer 300 exposed by the fourth photoresist layer 80 so as to obtain the anode 40 and the metal reflective layer 30, and the structural schematic diagram refers to fig. 17.

The metal reflective layer and the anode are simultaneously formed from the above steps S410 to S450.

In step S450, the transparent electrode layer and the metal layer not covered by the fourth photoresist layer 80 may be removed by step etching using different etching solutions, and referring to fig. 18, specifically: the step of removing the transparent electrode layer and the metal layer exposed by the fourth photoresist layer by etching comprises the following steps: s451: removing the transparent electrode layer 400 exposed by the fourth photoresist layer 80 by using the first etching solution so as to obtain the anode 40, wherein the first etching solution does not react with the metal layer (i.e. the first etching solution does not etch the metal layer); s452: the metal layer 300 not covered by the anode 40 is removed using the second etching liquid so as to obtain the metal reflective layer 30. In the steps, the metal reflecting layer and the anode are obtained by step-by-step etching, and the problem of etching rate difference does not exist, so that the occurrence of chamfering can be well avoided, and the connection quality of the circuit is improved.

The specific types of the first etching solution and the second etching solution are not limited, and those skilled in the art can select an appropriate etching solution according to the specific materials of the transparent electrode layer and the metal layer as long as the first etching solution does not react with the metal layer.

The inventor finds that in the manufacturing method, the metal layer at the through hole needs to be partially removed to obtain the metal reflecting layer, and the anode is directly contacted with the source electrode or the drain electrode exposed by the through hole to realize electric connection, namely, the metal reflecting layer does not exist in the through hole, so that the phenomenon of poor contact between the anode and the source electrode or the drain electrode due to the phenomenon of line breaking and cracking of the metal reflecting layer on the side wall of the through hole in the manufacturing process can be avoided, and the quality and the display effect of the display panel are improved; moreover, the manufacturing method is simple and easy to implement, is convenient for industrial mass production, and has high product yield. Moreover, the reflecting layer and the anode are obtained through distributed etching, so that the phenomenon that the reflecting layer is chamfered can be effectively avoided, the connection quality of the circuit is improved, and the product quality is ensured.

According to an embodiment of the present invention, the method for manufacturing a top-emitting OLED display backplane can be used for manufacturing the top-emitting OLED display backplane, wherein materials and specific structures of the reflective layer, the anode, and the like are the same as those described above, and are not described herein again.

In yet another aspect of the present invention, the present invention provides an OLED display device. According to an embodiment of the invention, the OLED display device comprises the aforementioned top-emitting OLED display backplane. Therefore, the OLED display device has good display effect and high yield. As will be understood by those skilled in the art, the OLED display device has all the features and advantages of the top-emitting OLED display backplane and the method for fabricating the same, and will not be described herein in any greater detail.

According to the embodiment of the present invention, the specific type of the OLED display device has no special requirement, and those skilled in the art can flexibly select the type according to the actual situation. In some embodiments, specific types of the display device include, but are not limited to, all devices or apparatuses with a display function, such as a mobile phone, a notebook, an iPad, a game machine, and the like.

It can be understood by those skilled in the art that, in addition to the top-emitting OLED display backplane, the OLED display device further includes structures or components necessary for a conventional OLED display device, and in addition to the top-emitting OLED display backplane, the OLED display device further includes structures or components such as a touch panel, an audio module, a camera module, a CPU, a fingerprint module, and the like, taking a mobile phone as an example.

The terms "first" and "second" are used herein for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.