Patent ID: 12239003

DETAILED DESCRIPTION OF EMBODIMENTS

The technical solutions in the embodiments of the present application are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, but are not all embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts are within the scope of the present application. Besides, it should be understood that the specific embodiments described herein are merely for describing and explaining the present application and are not intended to limit the present application. In the present application, unless opposite stated, the orientation words used such as “upper” and “lower” generally refer to the upper and lower directions of the device in actual using or working state, and specifically refer to the drawing directions in the drawings, and “inner” and “outer” refer to the outline of the device.

Embodiments of the present application provide a display panel and a manufacturing method thereof, and detailed descriptions are provided below. It should be noted that a description order of the following embodiments is not intended to limit a preferred order of the embodiments.

Please refer toFIG.2andFIG.3. One embodiment of the present application provides a display panel100, which includes a substrate11, a driving circuit layer12, a light-emitting device layer13, and an encapsulation layer14.

The driving circuit layer12is disposed on the substrate11. The driving circuit layer12includes an auxiliary electrode Fd and an undercut structure Uc disposed on the auxiliary electrode Fd. An undercut space Ck is defined on the undercut structure Uc. The auxiliary electrode Fd includes a connection portion f1. The connection portion f1extends along a peripheral direction of the undercut structure Uc. The connection portion f1is exposed by the undercut space Ck.

The light-emitting device layer13includes a first electrode131, and a pixel definition layer132, a light-emitting layer133, and a second electrode134disposed on the first electrode131. The first electrode131is disposed on the driving circuit layer12.

The light-emitting layer133and the second electrode134are cut at where the undercut structure Uc is. The second electrode134is connected to the connection portion f1of the auxiliary electrode Fd.

Wherein, a part of the light-emitting layer133and the second electrode134is disposed on the undercut structure Uc. The light-emitting layer133is disposed on the first electrode131and the pixel definition layer132. The second electrode134is disposed on the light-emitting layer133.

The encapsulation layer14covers the light-emitting device layer13. Specifically, the encapsulation layer14covers the second electrode134. The encapsulation layer14extends into the undercut space Ck and covers the second electrode134.

In the display panel100of the embodiments of the present application, an island-type undercut structure is adopted to replace a hole-type undercut structure in the prior art. Specifically, as the undercut structure Uc is disposed at middle of the auxiliary electrode Fd, the undercut structure Uc is located in the opening, and a slope of the surrounding hole wall is continuous, the hole wall has no protrusion portion in the prior art. When the encapsulation layer14is manufactured, the encapsulation layer14can completely cover the whole hole wall, can extend into the undercut space Ck, and can cover the second electrode134and the light-emitting layer133in the undercut space Ck, thereby improving the encapsulation effect of the encapsulation layer14. Therefore, the encapsulation effect of the display panel100is improved.

Optionally, please refer toFIG.3, the undercut structure Uc includes a support portion u1and a block portion u2. The auxiliary electrode Fd further includes a carrier portion f2. The connection portion f1is connected to a peripheral side of the carrier portion f2. The support portion u1is disposed on the carrier portion f2. The block portion u2includes a connection part u21and a hanged part u22connected to the connection part u21. The connection part u21is disposed on the support portion u1. The hanged part u22protrudes out from the support portion u1. Lateral surfaces of the hanged part u22and the support portion u1form the undercut space Ck.

Wherein, because there is a space between the hanged part u22and the hole wall of the first opening12a, the space and the undercut space Ck cause the light-emitting layer133to be cut at the undercut structure Uc and to expose the auxiliary electrode Fd. Then, by adjusting an evaporation deposition angle of the second electrode134, the second electrode134is made to connect to the auxiliary electrode Fd.

Optionally, the undercut space Ck extends along a peripheral direction of the support portion u1to form a ring shape. In this way, the encapsulation effect of the encapsulation layer14is improved.

In some embodiments, undercut structure Ck can be disposed on opposite sides of the undercut structure Uc, i.e., the undercut space Ck extends along the two sides of the periphery of the support portion u1to form two isolated undercut spaces Ck.

Optionally, a first opening12ais defined in the driving circuit layer12. The undercut structure Uc is disposed in the first opening12a. A thickness of the second electrode134gradually increases in a direction X from the support portion u1toward a hole wall of the first opening12ain the undercut space Ck. In other words, as the second electrode134enters into the undercut space Ck deeper, the thickness of the second electrode134decreases, thereby facilitating the encapsulation layer14to enter a space deep in the undercut space Ck, and increasing a probability that the encapsulation layer14covers the second electrode134.

Optionally, the encapsulation layer14covers the second electrode134located in the undercut space Ck, and the second electrode134covers the light-emitting layer133located in the undercut space Ck.

A thickness of the light-emitting layer133gradually increases in the direction X from the support portion u1toward the hole wall of the first opening12ain the undercut space Ck. In other words, as the light-emitting layer133enters into the undercut space Ck deeper, the thickness of the light-emitting layer133decreases, thereby facilitating the second electrode134to enter the space deep in the undercut space Ck, and increasing an area of the second electrode134connected to the auxiliary electrode Fd.

Optionally, the driving circuit layer12includes a passivation layer Pv disposed on the substrate11and a planarization layer Pln disposed on the passivation layer Pv. The auxiliary electrode Fd further includes a peripheral portion f3, and the peripheral portion f3is connected on a peripheral side of the connection portion f1. The passivation layer Pv covers the peripheral portion f3. The first opening12aincludes a first branch hole12a1and a second branch hole12a2communicated with each other. The first branch hole12a1is defined in the passivation layer Pv. The second branch hole12a2is defined in the planarization layer Pln. A hole wall of the second branch hole12a2is located at a periphery of a hole wall of the first branch hole12a1.

A width of the connection portion f1is greater than or equal to 4 μm. A distance from the block portion u2to the hole wall of the second branch hole12a2is greater than or equal to 6 μm.

Optionally, the width of the connection portion f1can be 4 μm, 5 μm, 6 μm, 8 μm, or 10 μm, etc., and the distance from the block portion u2to the hole wall of the second branch hole12a2can be 6 μm, 8 μm, 10 μm, 15 μm or 20 μm, etc.

Optionally, a thickness of the support portion u1ranges from 1400 angstroms to 5100 angstroms, for example, 1400 angstroms, 1500 angstroms, 2000 angstroms, 2500 angstroms, 4000 angstroms, 5000 angstroms, or 5100 angstroms.

Optionally, the driving circuit layer12further includes a light shielding layer121, a first insulation layer122, an active layer123, a second insulation layer124, a first metal layer125, a third insulation layer126, a second metal layer127, and a wiring layer128disposed on the substrate11.

The passivation layer Pv is disposed on the second metal layer127. The auxiliary electrode Fd is formed in the second metal layer127. The support portion u1is formed in the passivation layer Pv. The block layer u2is formed in the wiring layer128. The planarization layer Pln is disposed on the wiring layer128.

The auxiliary electrode Fd is formed in the second metal layer127. The support portion u1is formed in the passivation layer Pv. The block layer u2is formed in the wiring layer128, which can achieve an effect of saving steps and processes.

In this embodiment, the first metal layer125includes a gate electrode. The second metal layer127further includes a source electrode and a drain electrode. The wiring layer128includes a conductive pad. A first part of the active layer123, the gate electrode, the source electrode, and the drain electrode form a thin film transistor TFT. The conductive pad is connected to the source electrode of the thin film transistor TFT through a via hole. The source electrode is connected to a first part of a light shielding layer121by another via hole. The first part of the light shielding layer121shields the active layer123. The first electrode131is connected to the conductive pad.

A second part of the light shielding layer121, a second part of the active layer123, and a part of the second metal layer127are spaced apart and are overlapped with each other.

It should be noted that the structure of the thin film transistor with a top-gate structure is illustrated in the display panel100of this embodiment, but the present application is not limited thereto, for example, it may also be a structure of a bottom gate thin film transistor or a double-gate thin film transistor.

Optionally, materials of the block portion u2and the wiring layer128are same. The material of the wiring layer128can be metal, metal alloy, or metal oxide, etc., for example, a single layer structure of molybdenum (Mo), titanium (Ti), or an alloy of Mo and Ti, and can also be a multi-layer structure of Mo/Al/Mo, Al/Mo, Mo/Cu/Mo, MoTi/Cu/MoTi, Ti/Cu/Ti, or Ti/Al/Ti, etc.

Optionally, an material of the active layer123can be metal oxide semiconductor, or polycrystalline silicon, etc.

In some embodiments, the materials of the block portion u2and the wiring layer128can be different.

Optionally, a thickness of the passivation layer Pv ranges from 1 μm to 4 μm, for example, 1 μm, 2 μm, 3 μm, or 4 μm.

Optionally, a thickness of the planarization layer Pln ranges from 1 μm to 5 μm, for example, 1 μm, 2 μm, 3 μm, 4 μm, or 5 μm.

Of course, in some embodiments, the auxiliary electrode Fd and the second metal layer127can be formed in different steps, and the support portion u1and the passivation layer Pv can also be formed in different steps.

In this embodiment, the first electrode131is an anode, and the second electrode134is a cathode, but is not limited thereto.

A material of the light-emitting layer133can be an organic material or an inorganic material.

A second opening13ais defined in the pixel definition layer132. The second opening13ais defined on the first opening12aand communicates with the first opening12a.

Correspondingly, please refer toFIG.4, one embodiment of the present application further provides a manufacturing method of the display panel, which includes following steps:Step B1: forming a driving circuit layer on a substrate, wherein the driving circuit layer includes an auxiliary electrode;Step B2: forming a first electrode on the driving circuit layer;Step B3: etching a part of the driving circuit layer to form an undercut structure disposed on the auxiliary electrode, wherein an undercut space is defined on the undercut structure, the auxiliary electrode includes a connection portion, the connection portion extends along a peripheral direction of the undercut structure, and the connection portion is exposed by the undercut space;Step B4: forming a light-emitting layer and a second electrode on the first electrode in sequence, wherein the light-emitting layer and the second electrode are cut at where the undercut structure is, and the second electrode is connected to the connection portion of the auxiliary electrode; andStep B5: forming an encapsulation layer on the second electrode, wherein the encapsulation layer extends into the undercut space and covers the second electrode.

In the manufacturing method of the display panel of the embodiments of the present application, an island-type undercut structure is adopted to replace a hole-type undercut structure in the prior art. Specifically, as the undercut structure is disposed at middle of the auxiliary electrode, the undercut structure is located in the opening, and a slope of the surrounding hole wall is continuous, the hole wall has no protrusion portion in the prior art. When the encapsulation layer is manufactured, the encapsulation layer can completely cover the whole hole wall, can extend into the undercut space, and can cover the second electrode and the light-emitting layer in the undercut space, thereby improving the encapsulation effect of the encapsulation layer. Therefore, the encapsulation effect of the display panel is improved.

The manufacturing method of the display panel is described hereinafter.

In step B1, the driving circuit layer12is formed on the substrate11. Specifically, the step B1includes following steps.

Please refer toFIG.5, in step B11, a thin film transistor TFT and an auxiliary electrode Fd are formed on the substrate11. The auxiliary electrode Fd further includes a connection portion f1and a carrier portion f2. The connection portion f1is connected on a peripheral side of the carrier portion f2.

Optionally, the substrate11can be a rigid substrate or a flexible base. A material of the substrate11includes one of glass, sapphire, silicon, silicon dioxide, polyethylene, polypropylene, polystyrene, poly(lactic acid), polyethylene terephthalate, polyimide, or polyurethane.

Optionally, the thin film transistor TFT can be a top-gate type thin film transistor, a bottom-gate type thin film transistor, or a double-gate type thin film transistor. In this embodiment, the top-gate structure is taken as an example, but it is not limited thereto. The structures of bottom-gate or double-gate thin film transistors are the prior art, and redundant description will not be mentioned herein.

Optionally, the driving circuit layer12further includes a light shielding layer121, a first insulation layer122, an active layer123, a second insulation layer124, a first metal layer125, a third insulation layer126, a second metal layer127, and a wiring layer128disposed on the substrate11.

The auxiliary electrode Fd is formed in the second metal layer127, which can achieve an effect of saving steps and processes.

The auxiliary electrode Fd includes the connection portion f1. The auxiliary electrode Fd further includes a carrier portion f2. The connection portion f1is disposed on a peripheral side of the carrier portion f2.

In this embodiment, the first metal layer125includes a gate electrode. The second metal layer127further includes a source electrode and a drain electrode. The first part of the active layer123, the gate electrode, the source electrode, and the drain electrode form the thin film transistor. The source electrode is connected to a first part of a light shielding layer121by another via hole. The first part of the light shielding layer121shields the active layer123. A second part of the light shielding layer121, a second part of the active layer123, and a part of the second metal layer127are spaced apart and are overlapped with each other.

Optionally, an material of the active layer123can be metal oxide semiconductor, or polycrystalline silicon, etc.

Optionally, materials of the auxiliary electrode Fd and the second metal layer127can be same. The material of the second metal layer127can be metal, metal alloy, or metal oxide, etc.,

Please refer toFIG.5, in step B12, the passivation layer Pv is formed on the auxiliary electrode Fd.

Optionally, the material of the passivation layer Pv can include at least one of silicon nitride, silicon oxide, or organic photoresist.

A thickness of the passivation layer Pv ranges from 1 μm to 4 μm, for example, 11 μm, 2 μm, 3 μm, or 4 μm.

Please refer toFIG.5, in step B13, the block portion u2is formed on the passivation layer Pv, i.e., the wiring layer128is formed on the passivation layer Pv. The wiring layer128includes the block portion u2and the conductive pad. The conductive pad is connected to the source electrode of the thin film transistor through a via hole.

Optionally, materials of the block portion u2and the wiring layer128are same. The material of the second metal layer127can be metal, metal alloy, or metal oxide, etc., for example, a single layer structure of molybdenum (Mo), titanium (Ti), or an alloy of Mo and Ti, and can also be a multi-layer structure of Mo/Al/Mo, Al/Mo, Mo/Cu/Mo, MoTi/Cu/MoTi, Ti/Cu/Ti, or Ti/Al/Ti.

In some embodiments, the materials of the block portion u2and the wiring layer128can be different.

Please refer toFIG.6, in step B14, the planarization layer Pln is formed on the block portion u2. The second branch hole12a2is defined in the planarization layer Pln, and the block portion u2is exposed by the second branch hole12a2.

Optionally, a thickness of the planarization layer Pln ranges from 1 μm to 5 μm, for example, 1 μm, 2 μm, 3 μm, 4 μm, or 5 μm.

Optionally, a material of the planarization layer Pln can be an organic transparent film layer, for example, transparent photoresist, epoxy resin, polyimide, polyvinyl alcohol, polymethyl methacrylate, polystyrene, etc.

Then, go to step B2.

Please refer toFIG.7, in step B2, the first electrode131is formed on the planarization layer Pln.

Optionally, the first electrode131can be an anode, which includes a metal material having high reflectivity, for example, includes but is not limited to indium tin oxide/silver/indium tin oxide (ITO/Ag/ITO), indium zinc oxide/silver/indium zinc oxide (IZO/Ag/IZO), ITO/aluminum (Al)/ITO, or IZO/Al/IZO etc.

The first electrode131is connected to the conductive pad by using a via hole.

Then, go to step B3.

In the step B3, the part of the driving circuit layer12is etched to form the undercut structure Uc disposed on the auxiliary electrode Fd. The undercut space Ck is defined on the undercut structure Uc. The connection portion f1extends along the peripheral direction of the undercut structure Uc. The connection portion f1is exposed by the undercut space Ck.

Specifically, the step B3includes following steps.

Please refer toFIG.8, in step B31, the photoresist layer Pr is formed on the planarization layer Pln. The photoresist layer Pr covers a hole wall of the second branch hole12a2and exposes part of the block portion u2and the passivation layer Pv.

Optionally, a distance from the block portion u2to the photoresist layer Pr is greater than or equal to 5 μm, for example, 5 μm, 6 μm, 7 μm, or 8 μm, etc.

Please refer toFIG.9, in the step B32, the exposed passivation layer Pv is etched to form the undercut structure Uc and the first branch hole12a1.

The undercut structure Uc includes the block portion u2, and the support portion u1formed in the passivation layer Pv. The support portion u1is disposed on the carrier portion f2. The block portion u2includes the connection part u21and the hanged part u22connected to the connection part u21. The connection part u21is disposed on the support portion u1. The hanged part u22protrudes out from the support portion u1. Lateral surfaces of the hanged part u22and the support portion u1form the undercut space Ck.

Please refer toFIG.9andFIG.10, in step B33, the photoresist layer Pr is removed to form the second branch hole12a2.

The first opening12ais defined in the driving circuit layer12. The undercut structure Uc is disposed in the first opening12a. The first opening12aincludes a first branch hole12a1and a second branch hole12a2communicated with each other. The first branch hole12a1is formed in the passivation layer Pv. The second branch hole12a2is formed in the planarization layer Pln. A hole wall of the second branch hole12a2is located at a periphery of a hole wall of the first branch hole12a1.

The connection portion f1extends along the peripheral direction of the undercut structure Uc. The connection portion f1is exposed by the undercut space Ck.

The auxiliary electrode Fd further includes a peripheral portion f3, and the peripheral portion f3is connected on a peripheral side of the connection portion f1. The passivation layer Pv covers the peripheral portion f3.

A width of the connection portion f1is greater than or equal to 4 μm. A distance D from the block portion u2to the hole wall of the second branch hole12a2is greater than or equal to 6 μm.

Optionally, the width of the connection portion f1can be 4 μm, 5 μm, 6 μm, 8 μm, or 10 μm, etc., and the distance from the block portion u2to the hole wall of the second branch hole12a2can be 6 μm, 8 μm, 10 μm, 15 μm or 20 μm, etc.

Optionally, a thickness of the support portion u1ranges from 1400 angstroms to 5100 angstroms, for example, 1400 angstroms, 1500 angstroms, 2000 angstroms, 2500 angstroms, 4000 angstroms, 5000 angstroms, or 5100 angstroms.

Optionally, the undercut space Ck extends along a peripheral direction of the support portion u1to form a ring shape. In this way, the encapsulation effect of the encapsulation layer14in subsequent processes is improved.

In some embodiments, undercut structures Ck can be disposed on opposite sides of the undercut structure Uc, i.e., the undercut spaces Ck extend along the two sides of the periphery of the support portion u1to form two isolated undercut spaces Ck.

Then, go to step B4.

In the step B4, the pixel definition layer132, the light-emitting layer331, and the second electrode134are formed on the first electrode131in sequence. The light-emitting layer133and the second electrode134are cut at where the undercut structure Uc is. The second electrode134is connected to the connection portion f1of the auxiliary electrode Fd. The step B4includes following steps.

Please refer toFIG.11, in step B41, the pixel definition layer132is formed on the first electrode131.

A second opening13ais defined in the pixel definition layer132. The second opening13ais defined on the first opening12aand communicates with the first opening12a. A third opening13bis defined in the pixel definition layer132. The first electrode131is exposed by the third opening13b.

Please refer toFIG.12, in step B42, the light-emitting layer133is formed on the first electrode131.

The light-emitting layer133covers the first electrode131and the pixel definition layer132. The light-emitting layer133further covers hole walls of the first opening12aand the second opening13aand is disposed in the third opening13b. The light-emitting layer133is broken at the undercut structure Uc. Wherein, a part of the light-emitting layer133is further disposed on the undercut structure Uc.

In this embodiment, by a vapor deposition angle of the light-emitting layer133, the light-emitting layer133cannot completely cover the auxiliary electrode Fd below.

A thickness of the light-emitting layer133gradually increases in the direction X from the support portion u1toward the hole wall of the first opening12ain the undercut space Ck. In other words, as the light-emitting layer133enters into the undercut space Ck deeper, the thickness of the light-emitting layer133decreases, thereby facilitating the second electrode134of subsequent processes to enter the space deep in the undercut space Ck, and increasing an area of the second electrode134connected to the auxiliary electrode Fd.

Optionally, the light-emitting layer133can be an organic material.

Please refer toFIG.13, in step B43, the second electrode134is formed on the light-emitting layer133.

Optionally, the first electrode131, the pixel definition layer132, the light-emitting layer133, and the second electrode134form the light-emitting device layer13. It should be noted that the light-emitting device layer13includes but is not limited to the first electrode131, the pixel definition layer132, the light-emitting layer133, and the second electrode134, for example, an electron transport layer, a hole transport layer, etc. can be included.

The second electrode134is disposed on the light-emitting layer133, and the second electrode134is broken at where the undercut structure Uc is. Wherein, a part of the second electrode134is also disposed on the undercut structure Uc.

The second electrode134extends into the undercut space Uc. A thickness of the second electrode134gradually increases in a direction X from the support portion u1toward a hole wall of the first opening12ain the undercut space Ck. In other words, as the second electrode134enters into the undercut space Ck deeper, the thickness of the second electrode134decreases, thereby facilitating the encapsulation layer14of subsequent processes to enter a space deep in the undercut space Ck, and increasing a probability that the encapsulation layer14covers the second electrode134.

Then, go to step B5.

Please refer toFIG.15, in step B5, the encapsulation layer14is formed on the second electrode134.

Optionally, the encapsulation layer14covers the second electrode134located in the undercut space Ck, and the second electrode134covers the light-emitting layer133located in the undercut space Ck.

In this way, the manufacturing processes of the display panel100of this embodiment is finished.

The island-type undercut structure is adopted to replace a hole-type undercut structure in the prior art in the manufacturing method of the display panel of the embodiments of the present application, thereby improving encapsulation effect of the display panel.

Specifically, the display panel includes the driving circuit layer, the light-emitting layer, and the encapsulation layer. The driving circuit layer includes the auxiliary electrode and the undercut structure disposed on the auxiliary electrode. The undercut space is defined on the undercut structure. The auxiliary electrode includes the connection portion. The connection portion extends along the peripheral direction of the undercut structure. The connection portion is exposed by the undercut space. The light-emitting device layer includes the light-emitting layer and the second electrode. The light-emitting layer and the second electrode are cut at where the undercut structure is. The second electrode is connected to the connection portion of the auxiliary electrode. The encapsulation layer extends into the undercut space and covers the second electrode. Because the encapsulation layer can extend into the undercut space and can cover the second electrode and the light-emitting layer in the undercut space, the encapsulation effect of the encapsulation layer is improved.

The display panel and manufacturing method thereof provided by the embodiments of the present application are described in detail above. This article uses specific cases for describing the principles and the embodiments of the present application, and the description of the embodiments mentioned above is only for helping to understand the method and the core idea of the present application. Meanwhile, for those skilled in the art, will have various changes in specific embodiments and application scopes according to the idea of the present application. In summary, the content of the specification should not be understood as limit to the present application.