TW202105000A - Display panel - Google Patents

Abstract

A display panel including a substrate, a plurality of display pixels, a encapsulation structure layer and an auxiliary layer is provided. The substrate has a display region, a bendable region and a buffer region positioned between the display region and the bendable region. The display pixels are disposed in the display region. The encapsulation structure layer is overlapped with display region and covers the display pixels. The auxiliary layer is overlapped with the bendable region and has a top surface. A first height is included between the top surface of the auxiliary layer and a surface of the substrate. The auxiliary layer and the encapsulation structure layer define a recess overlapped with the buffer region. A second height is included between a bottom surface positioned in the buffer region of the recess and the surface of the substrate. The difference between the first height and the second height is greater than 0 microns and less than or equal to 4 microns.

Description

Display panel

The present invention relates to an electronic device, and particularly relates to a display panel.

With the development of display technology, the application range of display panels has become increasingly widespread. For example, in the early days, display panels were mostly used as screens for electronic devices (such as TVs, computers, mobile phones, etc.), while display panels used on electronic devices were mostly rigid display panels; in the recent past, some people have used display panels In wearable devices (for example: watches, clothes, etc.), the display panels applied to wearable devices are mostly flexible display panels. The flexible display panel needs to have a considerable degree of flexibility. In other words, when the flexible display panel is bent, the components on the flexible substrate (such as thin film transistors, data lines, scan lines, peripheral wiring, etc.) need to be bent accordingly and maintain normal functions.

In order to achieve the above-mentioned purpose, an additional film layer is arranged in the bending area so that the above-mentioned circuit component is arranged near the neutral axis, so that the stress on the circuit component can be minimized. However, the step difference between the additional film layer and the functional film layer in the display area is likely to cause the accumulation of bubbles during the manufacturing process of the display panel. When the display panel is bent, the circuit traces located near the level difference are easily broken under the deformation and extrusion of the bubbles, causing the flexible display panel to fail.

The present invention provides a display panel with better production yield.

The display panel of the present invention includes a substrate, a plurality of display pixels, a packaging structure and an auxiliary layer. The substrate has a display area, a bendable area, and a buffer area between the display area and the bendable area. A plurality of display pixels are arranged in the display area. The packaging structure is overlapped in the display area and covers these display pixels. The auxiliary layer is overlapped and arranged in the bendable area and has a top surface. There is a first height between the top surface of the auxiliary layer and the surface of the substrate. The auxiliary layer and the packaging structure define a groove overlapping the buffer zone. The groove has a second height between the bottom surface in the buffer zone and the surface of the substrate. The difference between the first height and the second height is greater than 0 micrometers and less than or equal to 4 micrometers.

In an embodiment of the present invention, the auxiliary layer of the above-mentioned display panel extends from the bendable area into the buffer area.

In an embodiment of the present invention, the above-mentioned display panel further includes an isolation structure layer disposed in the display area. The isolation structure layer defines a plurality of pixel regions, and a plurality of display pixels overlap these pixel regions. The auxiliary layer has a first sub-layer extending into the buffer zone, and the first sub-layer and the isolation structure layer are the same film layer.

In an embodiment of the present invention, the above-mentioned display panel further includes a flat layer. The flat layer is disposed in the display area and between the substrate and the isolation structure layer. The auxiliary layer also has a second sub-layer extending into the buffer zone, and the second sub-layer and the flat layer are the same film layer.

In an embodiment of the present invention, the above-mentioned display panel further includes a metal pattern. The metal pattern is arranged in the buffer zone and between the groove and the substrate.

In an embodiment of the present invention, the metal pattern of the above-mentioned display panel has a floating potential.

In an embodiment of the present invention, the display area, the buffer area, and the bendable area of the above-mentioned display panel are arranged in a first direction, and the extending direction of the metal pattern is perpendicular to the first direction.

In an embodiment of the present invention, the above-mentioned display panel further includes an insulating layer. The insulating layer is overlapped and arranged in the display area and extends into the buffer zone. The first portion of the insulating layer located in the display area has a first thickness. The second part of the insulating layer in the buffer zone has a second thickness, and the second thickness is greater than the first thickness.

In an embodiment of the present invention, the above-mentioned display panel further includes a signal line and an insulating layer overlapped in the display area. The signal line is electrically connected to a plurality of display pixels. The insulating layer covers the signal line and extends into the buffer zone.

In an embodiment of the present invention, the insulating layer of the above-mentioned display panel has a third height between the surface of the first part in the display area and the surface of the substrate. The insulating layer has a fourth height between the surface of the second part in the buffer zone and the substrate, and the fourth height is greater than the third height.

In an embodiment of the present invention, the above-mentioned display panel further includes a metal pattern. The metal pattern is arranged in the buffer zone and on the insulating layer. The auxiliary layer extends from the bendable area to the buffer area and covers the metal pattern.

In an embodiment of the present invention, the material of the auxiliary layer of the above-mentioned display panel includes an organic material.

In an embodiment of the present invention, the above-mentioned groove of the display panel has a width in the direction from the display area to the bendable area, and the width is greater than 10 microns.

Based on the foregoing, in the display panel of an embodiment of the present invention, the packaging structure overlapping the display area and the auxiliary layer overlapping the bendable area define a groove in the buffer zone. The height difference between the top surface of the auxiliary layer and the bottom surface of the groove is greater than 0 micrometers and less than or equal to 4 micrometers, which can avoid the accumulation of bubbles on the side of the groove close to the auxiliary layer during the manufacturing process of the display panel and the buffer The circuit traces in the area are broken due to the deformation and extrusion of the bubbles, which helps to improve the manufacturing process margin and production yield of the display panel.

As used herein, "approximately", "approximately", "essentially", or "substantially" includes the stated value and the average value within the acceptable deviation range of the specific value determined by a person of ordinary skill in the art, taking into account all The measurement in question and the specific number of errors associated with the measurement (ie, the limitations of the measurement system). For example, "about" can mean within one or more standard deviations of the stated value, or, for example, within ±30%, ±20%, ±15%, ±10%, ±5%. Furthermore, "about", "approximately", "essentially", or "substantially" used in this article can be based on measurement properties, cutting properties, or other properties to select a more acceptable deviation range or standard deviation. Not one standard deviation applies to all properties.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element, or Intermediate elements can also be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements. As used herein, "connection" can refer to physical and/or electrical connection. Furthermore, "electrical connection" can mean that there are other components between the two components.

In addition, relative terms such as "lower" or "bottom" and "upper" or "top" can be used herein to describe the relationship between one element and another element, as shown in the figure. It should be understood that relative terms are intended to include different orientations of the device in addition to the orientation shown in the figures. For example, if the device in one figure is turned over, elements described as being on the "lower" side of other elements will be oriented on the "upper" side of the other elements. Therefore, the exemplary term "lower" may include an orientation of "lower" and "upper," depending on the specific orientation of the drawing. Similarly, if the device in one figure is turned over, elements described as "below" or "below" other elements will be oriented "above" the other elements. Thus, the exemplary terms "above" or "below" can include an orientation of above and below.

Reference will now be made in detail to the exemplary embodiments of the present invention, and examples of the exemplary embodiments are illustrated in the accompanying drawings. Whenever possible, the same component symbols are used in the drawings and descriptions to indicate the same or similar parts.

FIG. 1 is a schematic top view of a display panel according to a first embodiment of the invention. FIG. 2 is a schematic cross-sectional view of the display panel of FIG. 1. Fig. 2 corresponds to the section line A-A' of Fig. 1. In particular, for the sake of clarity, FIG. 1 omits the substrate 100', the insulating layer 110, the insulating layer 120, the signal line 130, the insulating layer 140, the flat layer 150, the isolation structure layer 160, and the filling layer 200 of FIG. 2 for clarity. The drawing.

1 and FIG. 2, the display panel 10 includes a substrate 100 and a plurality of display pixels PX disposed on the substrate 100. In this embodiment, the substrate 100 is, for example, a flexible substrate, and the material of the flexible substrate may include polyimide (PI), polyethylene terephthalate (PET), and polycarbonate (polycarbonate). , PC), but the present invention is not limited to this. In other embodiments, the material of the substrate 100 may also include glass, quartz, or other suitable organic polymers.

The substrate 100 has a display area DR, a peripheral area PR, a buffer area BR, and a bendable area BDR. The buffer zone BR is located between the bendable area BDR and the display area DR. The peripheral area PR is located between the display area DR and the buffer area BR. The display area DR, the buffer area BR, and the bendable area BDR are sequentially arranged along the direction X. For example, in this embodiment, the peripheral area PR can be set around the display area DR, but the invention is not limited to this. In other embodiments, the peripheral area PR can also be arranged only on opposite sides of the display area DR, for example, on opposite sides of the display area DR in the direction X according to actual design requirements.

In this embodiment, a plurality of display pixels PX arranged in the display area DR may be arranged in an array on the substrate 100. For example, these display pixels PX may be arranged in a plurality of pixel rows along the direction X and the direction Y, respectively. Line with multiple pixels, but the present invention is not limited to this. It should be understood that the display panel 10 may also include multiple signal lines (not shown in FIG. 1). These signal lines respectively extend in the direction X and the direction Y, and are respectively electrically connected to the display pixels PX. For example, these signal lines may include data lines, scan lines, power lines, or sensing lines.

Furthermore, the display panel 10 may further include an insulating layer 110, an insulating layer 120, a signal line 130, an insulating layer 140, a flat layer 150, and an isolation structure layer 160 sequentially stacked on the substrate 100. In detail, the insulating layer 110 and the insulating layer 120 covering the display area DR extend to the bendable area BDR, and the stacked structure formed by the two insulating layers is in the portion of the bendable area BDR. ) Presents a stepped outline. Accordingly, the risk of disconnection of the signal line 130 here can be reduced. It is worth noting that the insulating layer 140 covering the display area DR only extends to the junction of the peripheral area PR and the buffer area BR, and does not extend to the buffer area BR and the bendable area BDR, but the present invention is not limited to this. In this embodiment, the insulating layer 110, the insulating layer 120, and the insulating layer 140 are made of inorganic materials (for example, silicon oxide, silicon nitride, silicon oxynitride, other suitable materials, or stacked layers of at least two of the foregoing materials). ), organic materials, or other suitable materials, or a combination of the above.

On the other hand, the isolation structure layer 160 disposed in the display region DR can define a plurality of pixel regions PXR of the display panel 10, and the plurality of display pixels PX are respectively in the normal direction of the substrate 100 (for example, direction Z). Overlap these pixel areas PXR. The display pixel PX includes a first electrode PE1, a second electrode PE2, and a light emitting structure EML that are sequentially stacked on the flat layer 150. The light emitting structure EML is sandwiched between the first electrode PE1 and the second electrode PE2. For example, the light emitting structure EML may include a hole injection layer (not shown), a hole transport layer (not shown), a light emitting layer (not shown), and an electron transport layer sequentially stacked on the first electrode PE1 (Not shown), but not limited to this.

The display pixel PX may also include an active element T. The first electrode PE1 penetrates the flat layer 150 and the insulating layer 140 to electrically connect to the drain electrode DE of the active device T. The source (not shown) of the active device T is electrically connected to the signal line 130. In this embodiment, the signal line 130 and the drain DE of the active device T may belong to the same film layer, but it is not limited to this. In this embodiment, the signal line 130 is, for example, a power line, and the first electrode PE1 and the second electrode PE2 are the anode and the cathode, respectively. When the active device T is enabled, current can be transmitted to the first electrode PE1 of the display pixel PX through the signal line 130 extending from the bendable region BDR to the display region DR. At this time, the light emitting structure EML can be driven by a current to emit a (visible) light beam, and the luminous intensity of the light beam can be controlled by the magnitude of the current or the driving time. Accordingly, the multiple display pixels PX of the display panel 10 can be independently driven to generate light beams of different intensities, and these light beams form a display screen after being transmitted to the human eye.

In this embodiment, the first electrode PE1 is, for example, a reflective electrode. The material of the reflective electrode includes metal, alloy, nitride of metal material, oxide of metal material, oxynitride of metal material, or other suitable materials. , Or stacked layers of metal materials and other conductive materials. The second electrode PE2 is, for example, a light-transmitting electrode. The material of the light-transmitting electrode includes metal oxides, such as indium tin oxide, indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, or other suitable materials. Oxide, or a stacked layer of at least two of the above. In other words, the display panel 10 of this embodiment is a top emission type display panel. However, the present invention is not limited to this. According to other embodiments, the display panel may also be a bottom emission type display panel.

On the other hand, the material of the flat layer 150 is, for example, an organic insulating material. The organic insulating material may include polyimide, polyester, benzocyclobutene (BCB), and polymethylmethacrylate (PMMA). , Poly(4-vinylphenol) (PVP), polyvinyl alcohol (PVA), polytetrafluoroethene (PTFE), hexamethyldisiloxane (HMDSO). The material of the isolation structure layer 160 may be similar to the material of the flat layer 150 or other suitable polymer materials, but the present invention is not limited thereto.

Furthermore, the display panel 10 further includes an encapsulation structure ES, which covers a plurality of display pixels PX and extends into the peripheral area PR. In this embodiment, the display panel 10 may also optionally include a retaining wall structure 190 disposed in the peripheral area PR. The vertical projection of the barrier structure 190 on the substrate 100 surrounds the display area DR and substantially defines the boundary of the packaging structure ES. For example, in the process of coating the packaging structure material, the arrangement of the barrier structure 190 can prevent the packaging structure material from overflowing to the buffer zone BR. In this embodiment, the barrier structure 190 may be a multi-layer stacked structure, for example: the first sub-layer 191 and the second sub-layer 192 stacked on the insulating layer 140 in sequence, and the first sub-layer 191 is located in the display area DR. The isolation structure layer 160 may belong to the same film layer, but the present invention is not limited to this. It should be noted that, in this embodiment, the number of retaining wall structures 190 is exemplified by taking two as an example, and the present invention is not limited thereto. In other embodiments, the number and configuration of the retaining wall structure 190 can also be adjusted according to actual design or manufacturing process requirements.

For example, the packaging structure ES may include a first packaging layer 171, a second packaging layer 172, and a third packaging layer 173 sequentially stacked on the insulating layer 140 (or display pixel PX). The second encapsulation layer 172 is filled between the first encapsulation layer 171 and the third encapsulation layer 173. In this embodiment, the material of the first encapsulation layer 171 and the third encapsulation layer 173 can be selectively the same, for example, silicon nitride (SiN _x ), but the invention is not limited to this. In other embodiments, the materials of the first encapsulation layer 171 and the third encapsulation layer 173 may also be different. On the other hand, the material of the second encapsulation layer 172 is, for example, acrylic, epoxy, hexamethyldisiloxane (HMDSO), or other suitable organic materials.

The display panel 10 further includes an auxiliary layer AXL and a filling layer 200. The auxiliary layer AXL is disposed in the bendable region BDR, and the filling layer 200 covers the packaging structure ES and the auxiliary layer AXL. It is worth noting that the auxiliary layer AXL and the package structure ES can define a groove RS overlapping the buffer zone BR. The auxiliary layer AXL has a top surface AXLs, and there is a first height H1 between the top surface AXLs and the surface 100s of the substrate 100. The groove RS has a second height H2 between the bottom surface RSs in the buffer zone BR and the surface 100s of the substrate 100. For example, in this embodiment, the difference between the first height H1 of the top surface AXLs of the auxiliary layer AXL and the second height H2 of the bottom surface RSs of the groove RS is 1.5 micrometers, but it is not limited thereto.

Through the difference between the first height H1 and the second height H2 (that is, the step difference between the top surface AXLs of the auxiliary layer AXL and the bottom surface RSs of the groove RS) is greater than 0 micrometers and less than or equal to 4 micrometers, which can avoid the filling layer 200 During the manufacturing process, bubbles are accumulated at the junction of the buffer zone BR and the bendable zone BDR (that is, the side of the groove RS close to the auxiliary layer AXL). Therefore, during the extrusion process of the filling layer 200, the circuit traces (such as the signal line 130) located in the buffer zone BR can be prevented from being broken due to the deformation and extrusion of the bubbles, which helps to improve the production yield of the display panel 10. Process margin.

In this embodiment, the auxiliary layer AXL may be a stacked structure including a plurality of sub-layers, for example, including a sub-layer 181, a sub-layer 182, and a sub-layer 183 that are sequentially stacked on the substrate 100. It should be noted that the sub-layer 181 of the auxiliary layer AXL and the package structure ES may define a groove RS'. Since the height difference between the bottom surface of the groove RS' (ie the surface of the signal line 130 or the insulating layer 120) and the top surface AXLs of the auxiliary layer AXL is too large, it extends from the bendable region BDR through the sub-layer 182 of the auxiliary layer AXL To the buffer zone BR and fill the groove RS', the aforementioned groove RS can be formed. In other words, the display panel 10 extends to the buffer zone BR through the sub-layer 182 of the auxiliary layer AXL and covers the insulating layer 120 and the signal line 130 to form a smaller depth (for example, the difference between the first height H1 and the second height H2). ) The groove RS. Accordingly, it is possible to avoid the accumulation of air bubbles at the junction of the buffer zone BR and the bendable area BDR (that is, the side of the groove RS close to the auxiliary layer AXL) during the manufacturing process of the filling layer 200.

It is worth mentioning that the vertical projection of the area between the sub-layer 181 of the auxiliary layer AXL and the package structure ES (that is, the area occupied by the groove RS') on the substrate 100 is in the direction of the display area DR toward the bendable area BDR (For example, the direction X) has a width W, and the width W is greater than 10 microns. Accordingly, the risk of bubbles accumulating at the junction of the buffer zone BR and the bendable zone BDR during the manufacturing process can be further reduced.

For example, in this embodiment, the material of the sub-layer 181 of the auxiliary layer AXL and the flat layer 150 located in the display area DR may be the same, and the material of the sub-layer 182 of the auxiliary layer AXL and the isolation structure layer 160 located in the display area DR are the same. Can be the same. That is, the sub-layer 181 of the auxiliary layer AXL and the flat layer 150 located in the display area DR may belong to the same film layer, and the sub-layer 182 of the auxiliary layer AXL and the isolation structure layer 160 located in the display area DR may belong to the same film layer. However, the present invention is not limited to this. The material of the sub-layer 183 of the auxiliary layer AXL and the second sub-layer 192 of the retaining wall structure 190 located in the peripheral area PR may be the same. In other words, the sub-layer 183 of the auxiliary layer AXL and the second sub-layer 192 of the barrier structure 190 located in the peripheral area PR may belong to the same film layer, but the present invention is not limited to this.

On the other hand, the material of the filling layer 200 may include acrylic, epoxy, hexamethyldisiloxane (HMDSO), or other suitable organic materials. In particular, the sub-layer 182 of the auxiliary layer AXL extends to the buffer zone BR and covers the signal line 130, which can prevent the stress from being concentrated near the circuit traces (such as the signal line 130) when the display panel 10 is bent. In addition, the material of the sub-layer 182 of the auxiliary layer AXL in this embodiment may be the same material as the flat layer 150 or other suitable polymer materials. The material of the filling layer 200 may be selected from acrylic, epoxy, hexamethyldisiloxane (HMDSO), or other suitable organic materials. When the display panel 10 is bent, the organic material with a softer texture can further disperse the stress in the buffer zone BR. In other words, the circuit traces can be prevented from being squeezed and broken by the sub-layer 182 of the filling layer 200 and the auxiliary layer AXL when the display panel 10 is bent.

Further, the display panel 10 may further include a substrate 100' disposed opposite to the substrate 100. For example, the substrate 100' may be selectively provided with a color filter layer, a light-shielding pattern layer, or other functional films or structures, which is not limited by the present invention. In this embodiment, the substrate 100' is, for example, a flexible substrate, and the material of the flexible substrate may include polyimide (PI), polyethylene terephthalate (PET), and polycarbonate ( polycarbonate, PC), but the present invention is not limited to this. In other embodiments, the material of the substrate 100' may also include glass, quartz, or other suitable organic polymers.

Other embodiments will be listed below to describe the disclosure in detail, wherein the same components will be marked with the same symbols, and the description of the same technical content will be omitted. For the omitted parts, please refer to the foregoing embodiments, and will not be repeated hereafter.

3 is a schematic cross-sectional view of a display panel according to a second embodiment of the invention. Please refer to FIG. 3, the difference between the display panel 11 of this embodiment and the display panel 10 of FIG. 2 is that the configuration of the auxiliary layer is different. Specifically, the sub-layer 181A and the sub-layer 182A of the auxiliary layer AXL-A of the display panel 11 extend from the bendable region BDR to the buffer zone BR and cover the insulating layer 120 and the signal line 130 to form a smaller depth (eg The difference between the first height H1 and the second height H2) of the groove RS-A.

For example, in this embodiment, the difference between the first height H1 of the top surface AXLs of the auxiliary layer AXL-A and the second height H2 of the bottom surface RSs of the groove RS-A is 1.0 μm, but this is not limit. Accordingly, it is possible to avoid the accumulation of air bubbles at the junction of the buffer zone BR and the bendable area BDR (that is, the side of the groove RS-A close to the auxiliary layer AXL-A) during the manufacturing process of the filling layer 200. Therefore, during the extrusion process of the filling layer 200, the circuit traces (such as the signal line 130) located in the buffer zone BR can be prevented from being broken due to the deformation and extrusion of the bubbles, which helps to improve the production yield of the display panel 11. Process margin.

4 is a schematic cross-sectional view of a display panel according to a third embodiment of the invention. FIG. 5 is a schematic cross-sectional view of the display panel of FIG. 4. Fig. 5 corresponds to the section line B-B' of Fig. 4. In particular, for the sake of clarity, FIG. 4 omits the insulating layer 110, the insulating layer 120A, the insulating layer 121, the signal line 130A, the insulating layer 140A, the flat layer 150, the isolation structure layer 160, and the filling layer 200 of FIG. 5 for clarity. The drawing.

Referring to FIGS. 4 and 5, the main difference between the display panel 12 of this embodiment and the display panel 10 of FIGS. 1 and 2 lies in the configuration of the auxiliary layer AXL and the composition of the display panel in the buffer zone. Specifically, the auxiliary layer AXL-B of the display panel 12 does not extend from the bendable area BDR to the buffer area BR. The display panel 12 further includes a plurality of metal patterns (for example, the metal pattern 115 and the metal pattern 125) and the insulating layer 121 disposed in the buffer zone BR, and the display panel 12 may not have the substrate 100' of FIG. 2. In detail, the metal pattern 115 is disposed between the insulating layer 110 and the insulating layer 120A, and the metal pattern 125 is disposed between the insulating layer 120A and the insulating layer 121. In this embodiment, the vertical projections of the two metal patterns on the substrate 100 can selectively overlap completely. However, the present invention is not limited to this. In other embodiments, the vertical projections of the two metal patterns on the substrate 100 may also partially overlap. On the other hand, the metal pattern 125 (or the metal pattern 115) can extend in the direction Y (that is, perpendicular to the arrangement direction X of the display area DR, the buffer area BR, and the bendable area BDR), but the present invention is not limited to this. . In other embodiments, the extension direction of the metal pattern can be adjusted according to actual design requirements (for example, the bendable direction of the display panel).

It is worth noting that by arranging two metal patterns in the buffer zone BR, the groove RS-B formed between the package structure ES and the auxiliary layer AXL-B can have a smaller depth (for example, the first height H1 and the first height H1). The difference between two heights H2). For example, in this embodiment, the difference between the first height H1 of the top surface AXLs of the auxiliary layer AXL-B and the second height H2 of the bottom surface RSs of the groove RS-B is 2.5 microns, but this is not limit. Accordingly, it is possible to avoid the accumulation of air bubbles at the junction of the buffer zone BR and the bendable area BDR (that is, the side of the groove RS-B close to the auxiliary layer AXL-B) during the manufacturing process of the filling layer 200. Therefore, during the extrusion process of the filling layer 200, the circuit traces located in the buffer zone BR (for example, the signal line 130A) can be prevented from being broken due to the deformation and extrusion of the bubbles, which helps to improve the production yield of the display panel 12. Process margin.

In particular, in this embodiment, the thickness of the insulating layer 121 in a part of the display region DR is different from the thickness of the insulating layer 121 in another part of the buffer zone BR. More specifically, the two portions of the insulating layer 121 located in the display area DR and the buffer area BR have a first thickness t1 and a second thickness t2, respectively, and the second thickness t2 is greater than the first thickness t1. Accordingly, the depth of the groove RS-B formed between the package structure ES and the auxiliary layer AXL-B (for example, the difference between the first height H1 and the second height H2) can be further reduced. On the other hand, in this embodiment, the interface between the sub-layer 181B and the sub-layer 182B of the auxiliary layer AXL-B can be aligned with the bottom surface RSs of the groove RS-B, but it is not limited to this. In addition, the cross-sectional profile of the sub-layer 182B and the sub-layer 183B of the auxiliary layer AXL-B on the side surface close to the buffer zone BR is arc-shaped, which can further reduce the accumulation of bubbles in the buffer zone BR and the bendable area BDR during the manufacturing process. The risk of the junction.

In this embodiment, the insulating layer 140A can extend from the display area DR to the bendable area BDR, and cover the circuit traces (such as the signal line 130A) in the buffer zone BR to prevent the filling layer 200 from directly contacting the circuit traces. It helps to improve the durability of the display panel 12. In particular, there is a third height H3 between a part of the surface 140As1 of the insulating layer 140A located in the display area DR and the surface 100s of the substrate 100, and the insulating layer 140A is located on the other part of the surface 140As2 (that is, concave) in the buffer zone BR. There is a fourth height H4 between the bottom surface RSs of the groove RS-B and the surface 100s of the substrate 100, and the fourth height H4 is greater than the third height H3.

Furthermore, the metal pattern 115 and the metal pattern 125 of this embodiment may have a floating potential; that is, the two metal patterns are not electrically connected to any signal traces or external power sources. In this embodiment, the material of the metal pattern 115 and the plurality of scanning lines (not shown) can be selectively the same, and the material of the metal pattern 125 and the plurality of sensing signal lines (not shown) can be selectively the same. In other words, the metal pattern 115 and the plurality of scan lines may belong to the same film layer, and the metal pattern 125 and the plurality of sensing signal lines may belong to the same film layer, but the present invention is not limited. By integrating the production of the metal pattern into the process of other functional film layers, additional production costs can be avoided.

6 is a schematic cross-sectional view of a display panel according to a fourth embodiment of the invention. Please refer to FIG. 6, the main difference between the display panel 13 of this embodiment and the display panel 12 of FIG. 5 is that the arrangement of the metal pattern and the auxiliary layer is different. Specifically, the metal pattern 125A of the display panel 13 is disposed on the insulating layer 140B. In other words, the display panel 13 may not have the insulating layer 121 of FIG. 5. Furthermore, the sub-layer 181C of the auxiliary layer AXL-C extends from the bendable region BDR to the buffer zone BR and covers the metal pattern 125A, so that the groove RS formed between the package structure ES and the auxiliary layer AXL-C -C has a small depth (for example, the difference between the first height H1 and the second height H2). Accordingly, it is possible to avoid the accumulation of air bubbles at the junction of the buffer zone BR and the bendable area BDR (that is, the side of the groove RS-C close to the auxiliary layer AXL-C) during the manufacturing process of the filling layer 200. Therefore, during the extrusion process of the filling layer 200, the risk of the circuit traces (such as the signal line 130) located in the buffer zone BR being broken due to the deformation and extrusion of the bubbles is reduced, which helps to improve the production yield of the display panel 13 And process margin.

In summary, in the display panel of an embodiment of the present invention, the packaging structure overlapping the display area and the auxiliary layer overlapping the bendable area define a groove in the buffer zone. The height difference between the top surface of the auxiliary layer and the bottom surface of the groove is greater than 0 micrometers and less than or equal to 4 micrometers, which can avoid the accumulation of bubbles on the side of the groove close to the auxiliary layer during the manufacturing process of the display panel and the buffer The circuit traces in the area are broken due to the deformation and extrusion of the bubbles, which helps to improve the manufacturing process margin and production yield of the display panel.

10, 11, 12, 13: display panel 100, 100’: Substrate 100s, 140As1, 140As2: surface 110, 120, 121, 140, 140A, 140B: insulating layer 115, 125, 125A: metal pattern 130, 130A: signal line 150: flat layer 160: Isolation structure layer 171: The first encapsulation layer 172: The second encapsulation layer 173: The third encapsulation layer 181, 181A, 181B, 181C, 182, 182A, 182B, 183, 183B: sub-layer 190: retaining wall structure 191, 192: sub-layer 200: Filling layer AXL, AXL-A, AXL-B, AXL-C: auxiliary layer AXLs: top surface BDR: bendable area BR: buffer DE: Dip pole DR: display area EML: light-emitting structure ES: Package structure H1, H2, H3, H4: height PE1: first electrode PE2: second electrode PR: Peripheral area PX: Display pixels PXR: pixel area RS, RS’, RS-A, RS-B, RS-C: groove RSs: bottom surface T: Active component t1, t2: thickness W: width X, Y, Z: direction A-A’, B-B’: Sectional line

FIG. 1 is a schematic top view of a display panel according to a first embodiment of the invention. FIG. 2 is a schematic cross-sectional view of the display panel of FIG. 1. 3 is a schematic cross-sectional view of a display panel according to a second embodiment of the invention. 4 is a schematic cross-sectional view of a display panel according to a third embodiment of the invention. FIG. 5 is a schematic cross-sectional view of the display panel of FIG. 4. 6 is a schematic cross-sectional view of a display panel according to a fourth embodiment of the invention.

10: Display panel

100, 100’: Substrate

100s: surface

110, 120, 140: insulating layer

130: signal line

150: flat layer

160: Isolation structure layer

171: The first encapsulation layer

172: The second encapsulation layer

173: The third encapsulation layer

181, 182, 183: sub-layer

190: retaining wall structure

191, 192: sub-layer

200: Filling layer

AXL: auxiliary layer

AXLs: top surface

BDR: bendable area

BR: buffer

DE: Dip pole

DR: display area

EML: light-emitting structure

ES: Package structure

H1, H2: height

PE1: first electrode

PE2: second electrode

PR: Peripheral area

PX: Display pixels

PXR: pixel area

RS, RS’: Groove

RSs: bottom surface

T: Active component

W: width

X, Y, Z: direction

A-A’: Sectional line

Claims (13)

A display panel including: A substrate having a display area, a bendable area, and a buffer area between the display area and the bendable area; Multiple display pixels are arranged in the display area; An encapsulation structure arranged in the display area overlapping and covering the display pixels; and An auxiliary layer is overlapped and arranged in the bendable area and has a top surface, wherein there is a first height between the top surface of the auxiliary layer and a surface of the substrate, and the auxiliary layer and the packaging structure define A groove overlapped with the buffer zone, and the groove has a second height between a bottom surface in the buffer zone and the surface of the substrate, and the difference between the first height and the second height is greater than 0 microns and less than or equal to 4 microns. The display panel according to claim 1, wherein the auxiliary layer extends from the bendable area into the buffer zone. The display panel described in claim 2 further includes: An isolation structure layer is disposed in the display area, the isolation structure layer defines a plurality of pixel areas, and the display pixels overlap the pixel areas respectively, wherein the auxiliary layer has an auxiliary layer extending into the buffer area A first sub-layer, and the first sub-layer and the isolation structure layer are the same film layer. The display panel described in claim 3 further includes: A flat layer is disposed in the display area and located between the substrate and the isolation structure layer, wherein the auxiliary layer also has a second sub-layer extending into the buffer zone, and the second sub-layer and the The flat layer is the same film layer. The display panel as described in claim 1, further including: A metal pattern is arranged in the buffer zone and located between the groove and the substrate. The display panel according to claim 5, wherein the metal pattern has a floating potential. The display panel according to claim 5, wherein the display area, the buffer area, and the bendable area are arranged in a first direction, and the extending direction of the metal pattern is perpendicular to the first direction. The display panel described in claim 5 further includes: An insulating layer is overlapped and arranged in the display area and extends into the buffer area. A first portion of the insulating layer in the display area has a first thickness, and a second portion of the insulating layer in the buffer area has a A second thickness, and the second thickness is greater than the first thickness. The display panel as described in claim 1, further including: A signal line to electrically connect the display pixels; and An insulating layer is overlapped and arranged in the display area. The insulating layer covers the signal line and extends into the buffer zone. The display panel according to claim 9, wherein the insulating layer is located at a third height between a surface of a first portion of the display area and the surface of the substrate, and the insulating layer is located at a surface of the buffer zone. There is a fourth height between a surface of the second part and the substrate, and the fourth height is greater than the third height. The display panel described in claim 9 further includes: A metal pattern is disposed in the buffer zone and on the insulating layer, wherein the auxiliary layer extends from the bendable area into the buffer zone and covers the metal pattern. The display panel according to claim 1, wherein the material of the auxiliary layer includes an organic material. The display panel according to claim 1, wherein the groove has a width in a direction from the display area to the bendable area, and the width is greater than 10 microns.

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