Display panel and display device

Abstract

This application provides a display panel and a display device, relating to the field of display technology. The display panel includes a pixel area and a spacing area connected to the pixel area; the display panel is provided with a light-emitting device and a driving circuit, the light-emitting device being located within the pixel area, and the connection point between the light-emitting device and the driving circuit being located within the spacing area and adjacent to the pixel area; the pixel area and the spacing area are covered with a planarization layer, the thickness of the planarization layer located in the spacing area is T1, the thickness of the planarization layer located in the pixel area is T2, and (T1-T2) / T2≤0.8. Laser repair is less prone to cosmetic defects.

Description

Technical Field

[0001] This application relates to the field of display technology, and more particularly to a display panel and a display device. Background Technology

[0002] When dark spots are found in the display panel during the manufacturing process, they are usually repaired by irradiating the area near the dark spot with a laser. However, the area irradiated by the laser is prone to appearance defects. Summary of the Invention

[0003] Embodiments of this application provide a display panel and display device that are less prone to appearance defects after laser repair.

[0004] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0005] On the one hand, this application provides a display panel, including a pixel area and a spacing area connected to the pixel area;

[0006] The display panel is provided with a light-emitting device and a driving circuit. The light-emitting device is located in the pixel area, and the connection point between the light-emitting device and the driving circuit is located in the interval area and is arranged adjacent to the pixel area.

[0007] The pixel area and the interval area are covered by a flattening layer. The thickness of the flattening layer in the interval area is T1, and the thickness of the flattening layer in the pixel area is T2, where (T1-T2) / T2≤0.8.

[0008] In some embodiments, the planarization layer is an optical adhesive layer.

[0009] In some embodiments, the display panel includes a display substrate and a cover plate, the light-emitting device and the driving circuit are disposed on the display substrate, and the planarization layer covers the display substrate and connects the cover plate and the display substrate.

[0010] In some embodiments, the display panel includes a plurality of pixel areas, the plurality of pixel areas being arranged at intervals, and the intervals being located between two adjacent pixel areas;

[0011] One of the pixel areas is configured as a pixel for displaying a pattern.

[0012] In some embodiments, the interval is a light-transmitting area, through which light can pass from one side of the display panel to the other.

[0013] In some implementations, the area of ​​the spacing region is larger than the area of ​​the pixel region.

[0014] In some implementations, (T1-T2) / T2≤0.7.

[0015] In some implementations, 15um ≤ T1 ≤ 19um.

[0016] In some implementations, 8um ≤ T2 ≤ 12um.

[0017] On the other hand, this application provides a display device including the aforementioned display panel.

[0018] The display panel provided in this application includes a pixel area and a spacing area connected to the pixel area. The display panel is provided with a light-emitting device and a driving circuit. The light-emitting device is located in the pixel area, and the connection point of the light-emitting device and the driving circuit is located in the spacing area and adjacent to the pixel area. The pixel area and the spacing area are covered with a planarization layer. The thickness of the planarization layer in the spacing area is T1, and the thickness of the planarization layer in the pixel area is T2, where (T1-T2) / T2≤0.8. The difference between T1 and T2 is not changed, but the ratio of the difference between T1 and T2 to T2 is changed. That is, by simultaneously increasing T1 and T2, the ratio of the difference between T1 and T2 to T1 or T2 is reduced when the difference between T1 and T2 is constant. This reduces the proportion of the expansion difference caused by the difference in the overall expansion of the planarization layer, thus reducing the expansion difference between different areas of the planarization layer and preventing film peeling caused by inconsistent expansion between the upper and lower film layers of the planarization layer, thereby reducing the likelihood of appearance defects. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram illustrating laser repair of a display panel using related technologies;

[0021] Figure 2 A schematic diagram showing a display panel after laser repair for related technologies;

[0022] Figure 3 This is a partial cross-sectional view of a display panel provided in an embodiment of this application.

[0023] Figure label:

[0024] 10 - Pixel area; 11 - White subpixel; 12 - Red subpixel; 13 - Green subpixel; 14 - Blue subpixel;

[0025] 20-interval zone;

[0026] 30-Planning layer;

[0027] 40 - Display substrate;

[0028] 50 - Connection point. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] In the embodiments of this application, the terms "first", "second", "third", "fourth" are used to distinguish the same or similar items with essentially the same function and effect, only for the purpose of clearly describing the technical solution of the embodiments of this application, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated.

[0031] In the embodiments of this application, "multiple" means two or more, and "at least one" means one or more, unless otherwise explicitly defined.

[0032] In the embodiments of this application, the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0033] like Figures 1 to 3 As shown, this application embodiment provides a display panel, which can be an OLED display panel or other types of display panels. The following description only uses an OLED display panel as an example.

[0034] The display panel may include a display area and a non-display area surrounding the display area. The display area may include a pixel area 10 and a spacing area 20 connected to the pixel area. The display panel is provided with light-emitting devices and driving circuits. The light-emitting devices are located within the pixel area 10, and the connection point 50 between the light-emitting devices and the driving circuits is located within the spacing area 20 and adjacent to the pixel area 10. The pixel area 10 and the spacing area 20 are covered by a planarization layer 30. The thickness of the planarization layer 30 in the spacing area 20 is T1, and the thickness of the planarization layer 30 in the pixel area 10 is T2.

[0035] When the display panel is working, the pixel area 10 has a light-emitting device, so it can emit light and display an image; while the interval area 20 does not have a light-emitting device, so the interval area 20 does not emit light.

[0036] The light-emitting device includes an anode and a cathode. The connection point 50 between the driving circuit and the light-emitting device can be the connection point between the driving circuit and the anode, or it can be the connection point between the driving circuit and the cathode. Here, connection point 50 refers to the overlapping structure between the driving circuit and the anode or cathode of the light-emitting device, and the specific overlapping structure is not limited here.

[0037] Before the planarization layer 30 is applied, different devices are arranged in different areas of the display panel, resulting in varying thicknesses (thickness refers to the dimension perpendicular to the light-emitting surface of the display panel) in different areas. To make the display panel relatively flat throughout, a planarization layer 30 is provided. The planarization layer 30 is thicker in the recessed areas of the display panel and thinner in the raised areas to compensate for the thickness differences. For example, the pixel area 10 contains light-emitting devices and is thicker, while the spacing area 20 does not contain light-emitting devices and is thinner. Therefore, the planarization layer 30 in the pixel area 10 is thinner, and the planarization layer 30 in the spacing area 20 is thicker.

[0038] It should be noted that the planarization layer 30 located in pixel region 10 and the planarization layer 30 located in spacing region 20 are integral structures. The material of the planarization layer 30 can be optical adhesive (e.g., epoxy resin) or other materials, which is not limited in this application. When the planarization layer 30 is an optical adhesive layer, the optical adhesive has good leveling properties, which makes the planarization layer 30 adhere more tightly and has a better flatness effect.

[0039] The display panel includes a display substrate 40 and a cover plate. Light-emitting devices and driving circuits are disposed on the display substrate 40. A planarization layer 30 covers the display substrate 40 and connects the cover plate and the display substrate 40.

[0040] For example, the display panel has a Dam & Fill package structure. After the display substrate 40 is fabricated, optical adhesive is applied to one side of the cover plate, and then the side of the cover plate with optical adhesive is attached to the display substrate 40, so that the optical adhesive can compensate for the unevenness of the surface of the display substrate 40 and bond the display substrate 40 and the cover plate.

[0041] When a defect occurs at the connection point 50 between the light-emitting device and the driving circuit, the light-emitting device will fail to light up because the correct driving voltage cannot be applied, resulting in dark spots on the display panel. In this case, laser repair is required to fix the dark spots. During laser repair, a laser is used to irradiate the area near the connection point between the light-emitting device and the driving circuit, raising the temperature in the vicinity of the connection point and causing the associated traces to melt, thus allowing the light-emitting device to function normally. For example, a laser with an energy of 120 kcal / kg can be used to irradiate the area three times, or a laser with an energy of 300 kcal / kg can be used to irradiate it once.

[0042] Figure 1 A schematic diagram illustrating laser repair of a display panel for related technologies. Figure 1 The pixel area 10 on the left is the first pixel area, and the pixel area 10 on the right is the second pixel area. The area between the first and second pixel areas is the interval area 20. Within the second pixel area, the square contains the first sub-pixel. The highlighted area within the elliptical frame in the interval area 20 is the laser-illuminated area, which is also the connection point of the light-emitting device and driving circuit contained in the first sub-pixel. Figure 1 As shown, during laser repair, the elliptical frame area is irradiated with a laser, causing the temperature within the elliptical frame area to rise, thereby melting the traces located within the elliptical frame area and completing the repair of the first sub-pixel.

[0043] Figure 2 A schematic diagram showing the display panel after laser repair using related technologies. (Example) Figure 2 As shown, after laser repair, the laser-irradiated area (elliptical frame area) and the surrounding area will have poor appearance.

[0044] The inventors discovered that the appearance defects are caused by the peeling of the film layers in the display panel. Specifically, when the planarization layer 30 is heated by laser irradiation, the thickness of the planarization layer in the spacing region 20 differs from that in the pixel region 10. This difference in thickness leads to different expansion amounts in the planarization layer in the spacing region 20 and the planarization layer in the pixel region 10, causing stress on adjacent film layers of the planarization layer 30 and resulting in film peeling and thus appearance defects. In short, the appearance defects caused by laser repair are due to the difference in expansion amounts between different areas of the planarization layer 30.

[0045] For example, the display panel is a top-emitting OLED display panel, the planarization layer 30 is an optical adhesive, the thickness T1 of the planarization layer in the spacing region 20 is 12µm, and the thickness T2 of the planarization layer in the pixel region 10 is 5µm. In this case, (T1-T2) / T2=(12-5) / 5=1.4. When laser irradiation is applied to the boundary between the spacing region 20 and the planarization region, if the laser energy is greater than 120 kJ / m², the display panel is prone to appearance defects after laser repair.

[0046] To eliminate or reduce appearance defects after laser repair, one possible approach is to improve the appearance defects caused by OLED film peeling by increasing the laser irradiation time instead of increasing the laser energy, thereby improving the curing rate of the planarization layer. However, increasing the laser irradiation time would significantly increase the product production cycle time and reduce production efficiency. Therefore, this approach of increasing the laser irradiation time is not adopted.

[0047] To eliminate or reduce appearance defects, it is necessary to reduce the expansion difference between different areas of the planarization layer 30. At the same temperature, the magnitude of the expansion difference depends on the thickness difference of the planarization layer 30. Since the thickness difference between the planarization layer 30 located in the spacing region 20 and the planarization layer 30 located in the pixel region 10 depends on the device structure design and layout of the display panel, it is determined after the design is completed and cannot be changed.

[0048] In this embodiment, (T1-T2) / T2 ≤ 0.8. The difference between T1 and T2 remains unchanged, but the ratio of the difference between T1 and T2 to T2 is changed. That is, by simultaneously increasing T1 and T2, the ratio of the difference between T1 and T2 to T1 or T2 decreases when the difference between them is constant. This reduces the proportion of the expansion difference caused by the difference in the overall expansion of the planarization layer 30, thus reducing the expansion difference between different regions of the planarization layer 30 and preventing film peeling caused by inconsistent expansion between the upper and lower film layers of the planarization layer 30.

[0049] The display panel provided in this application includes a pixel region 10 and a spacing region 20 connected to the pixel region 10. The display panel is provided with a light-emitting device and a driving circuit. The light-emitting device is located within the pixel region 10, and the connection point 50 between the light-emitting device and the driving circuit is located within the spacing region 20 and adjacent to the pixel region 10. The pixel region 10 and the spacing region 20 are covered by a planarization layer 30. The thickness of the planarization layer in the spacing region 20 is T1, and the thickness of the planarization layer in the pixel region 10 is T2, where (T1-T2) / T2≤0.8. The difference between T1 and T2 is not changed, but the ratio of the difference between T1 and T2 to T2 is changed. That is, by simultaneously increasing T1 and T2, the ratio of the difference between T1 and T2 to T1 or T2 decreases when the difference between T1 and T2 is constant. This reduces the proportion of the expansion difference caused by the difference in the overall expansion of the planarization layer 30, thus reducing the expansion difference between different areas of the planarization layer 30 and preventing film peeling caused by inconsistent expansion between the upper and lower film layers of the planarization layer 30, thereby reducing the likelihood of appearance defects.

[0050] For example, the display panel is a top-emitting OLED display panel. The planarization layer thickness T1 in the spacing region 20 is 16µm, and the planarization layer thickness T2 in the pixel region 10 is 9µm. At this time, (T1-T2) / T2=(16-9) / 9=0.78<0.8. In this case, the laser irradiation energy during laser modification can be increased to 200, and no appearance defects caused by film peeling will occur after laser repair.

[0051] Because the energy of laser irradiation is increased, the time required to melt the display panel traces is shorter, reducing production cycle time and improving production efficiency.

[0052] Furthermore, (T1-T2) / T2≤0.7. In this case, the planarization layer 30 located in the interval region 20 and the planarization layer 30 located in the pixel region 10 are thicker, which reduces the proportion of the thickness difference in the thickness of the planarization layer 30, thereby reducing the difference in the amount of expansion between different regions when the planarization layer 30 is heated, making it less likely for the display panel to have appearance defects after laser repair.

[0053] For example, the display panel is a top-emitting OLED display panel. The planarization layer thickness T1 in the spacing region 20 is 18 μm, and the planarization layer thickness T2 in the pixel region 10 is 11 μm. In this case, (T1-T2) / T2=(18-11) / 11=0.63<0.7. At this time, the laser irradiation energy during laser modification can be increased to 300, and no appearance defects caused by film peeling will occur after laser repair.

[0054] Because the energy of laser irradiation has been increased to 300, the time required to melt the display panel traces is shorter, reducing production cycle time and improving production efficiency.

[0055] It should be noted that the above explanation only uses (T1-T2) / T2 as an example, that is, the thickness of the planarization layer 30 is limited by the proportion of the difference between T1 and T2 in T2.

[0056] In practical applications, (T1-T2) / T1 can also be used, that is, the thickness of the planarization layer 30 is limited by the proportion of the difference between T2 and T1 in T1. In this case, the numerical range of the formula needs to be adjusted accordingly.

[0057] For example, (T1-T2) / T1 ≤ 0.5. For instance, if the display panel is a top-emitting OLED display panel, the planarization layer thickness T1 in the spacing region 20 is 16µm, and the planarization layer thickness T2 in the pixel region 10 is 9µm, then (T1-T2) / T1 = (16-9) / 16 = 0.43 < 0.5. In this case, the laser irradiation energy during laser modification can be increased to 200, and laser repair will not result in appearance defects caused by film peeling.

[0058] For example, (T1-T2) / T1 ≤ 0.4. For instance, if the display panel is a top-emitting OLED display panel, the planarization layer thickness T1 in the spacing region 20 is 18 μm, and the planarization layer thickness T2 in the pixel region 10 is 11 μm, then (T1-T2) / T2 = (18-11) / 18 = 0.38 < 0.4. In this case, the laser irradiation energy during laser modification can be increased to 300, and laser repair will not result in appearance defects caused by film peeling.

[0059] It can also be T1 / (T1-T2).

[0060] For example, T1 / (T1-T2) ≥ 2.2. For instance, if the display panel is a top-emitting OLED display panel, the planarization layer thickness T1 in the spacing region 20 is 16µm, and the planarization layer thickness T2 in the pixel region 10 is 9µm, then T1 / (T1-T2) = 16 / (16-9) = 2.28 > 2.2. In this case, the laser irradiation energy during laser modification can be increased to 200, and laser repair will not result in appearance defects caused by film peeling.

[0061] For example, T1 / (T1-T2) ≥ 2.5. For instance, if the display panel is a top-emitting OLED display panel, the planarization layer thickness T1 in the spacing region 20 is 18 μm, and the planarization layer thickness T2 in the pixel region 10 is 11 μm, then T1 / (T1-T2) = 18 / (18-11) = 2.57 > 2.5. In this case, the laser irradiation energy during laser modification can be increased to 300, and laser repair will not result in appearance defects caused by film peeling.

[0062] It can also be T2 / (T1-T2).

[0063] For example, T2 / (T1-T2) ≥ 1.2. For instance, if the display panel is a top-emitting OLED display panel, the planarization layer thickness T1 in the spacing region 20 is 16µm, and the planarization layer thickness T2 in the pixel region 10 is 9µm, then T2 / (T1-T2) = 9 / (16-9) = 1.28 > 1.2. In this case, the laser irradiation energy during laser modification can be increased to 200, and laser repair will not result in appearance defects caused by film peeling.

[0064] For example, T2 / (T1-T2) ≥ 1.5. For instance, if the display panel is a top-emitting OLED display panel, the planarization layer thickness T1 in the spacing region 20 is 18 μm, and the planarization layer thickness T2 in the pixel region 10 is 11 μm, then T2 / (T1-T2) = 11 / (18-11) = 1.57 > 1.5. In this case, the laser irradiation energy during laser modification can be increased to 300, and laser repair will not result in appearance defects caused by film peeling.

[0065] Of course, there are also variations of the above formula, which will not be listed here. The idea is to increase the thickness of the planarization layer located in pixel region 10 and the thickness of the planarization layer located in interval region 20, so that the thickness difference between the planarization layer 30 located in pixel region 10 and the planarization layer 30 located in interval region 20 is a smaller proportion of the thickness value of the planarization layer 30.

[0066] In some implementations, 15µm ≤ T1 ≤ 19µm. For example, T1 is 16µm or 18µm, etc. This allows for increased laser irradiation energy without significantly increasing the thickness of the planarization layer 30.

[0067] In some implementations, 8µm ≤ T2 ≤ 12µm. For example, T2 is 12µm or 8µm, etc. This allows for increased laser irradiation energy without significantly increasing the thickness of the planarization layer 30.

[0068] The display area may include multiple pixel areas 10, which are arranged at intervals, with interval areas 20 located between adjacent pixel areas 10. When the display panel is working, each pixel area 10 emits light of a specific color, thereby enabling the multiple pixel areas 10 to cooperate in displaying an image. Each pixel area 10 may contain one or more sub-pixels.

[0069] For example, a pixel area 10 is configured to display a pixel of a pattern, and multiple pixel areas 10 are arranged in a rectangular array to form multiple pixel rows and multiple pixel columns, with a spacing area 20 located between two adjacent pixel columns.

[0070] A pixel area 10 can include multiple sub-pixels, and different sub-pixels can emit different light, so that multiple sub-pixels work together to emit light of a specific color.

[0071] For example, such as Figure 2 As shown, a pixel area 10 includes four sub-pixels: a white sub-pixel 11, a red sub-pixel 12, a green sub-pixel 13, and a blue sub-pixel 14. Alternatively, the light-emitting device may also include three sub-pixels, emitting red, green, and blue light respectively; or, the light-emitting device may include four sub-pixels, emitting green, red, and blue light respectively.

[0072] At this point, due to the different device structures of the different color subpixels, the thickness of the planarization layer 30 varies at different subpixel locations. For example, the thickness of the planarization layer 30 at the red subpixel 12 is 4.96 μm, the thickness at the green subpixel 13 is 5.41 μm, and the thickness at the blue subpixel 14 is 5.52 μm. The thickness difference between the different color subpixels is small, making it less likely that differences in film thickness will lead to differences in expansion, thereby causing film peeling.

[0073] For example, a pixel structure includes multiple light-emitting devices that emit light of the same color, such as white light. Different light-emitting devices can emit different colors of light by using filters on them.

[0074] The embodiments of this application do not limit the number of sub-pixels included in a pixel structure or the color of the emitted light.

[0075] A pixel area 10 can also contain multiple pixels, and each pixel includes multiple sub-pixels. Adjacent pixels can share sub-pixels.

[0076] The interval 20 can be a light-transmitting area, through which light can pass from one side of the display panel to the other.

[0077] For example, the interval area 20 and the pixel area 10 are arranged in an array and spaced apart, so as to make the display panel transparent while displaying the image, allowing the user to see the object behind the display panel.

[0078] In practical applications, fewer film layers can be placed within the spacer region 20 to reduce the amount of light blocked by the film structure. When conductive traces are provided within the spacer region 20, transparent electrodes, such as indium tin oxide, can be used.

[0079] The area of ​​the interval region 20 can be larger than the area of ​​the pixel region 10. This improves the transparency of the display panel.

[0080] On the other hand, this application provides a display device, which may be a mobile phone, laptop computer, ultra-mobile personal computer (UMPC), netbook, personal digital assistant (PDA), wearable device, virtual reality device or mobile computing device or other device with a display panel. The embodiments of this application do not limit this.

[0081] The display device provided in this application includes a pixel area and an interval area connected to the pixel area; the display panel is provided with a light-emitting device and a driving circuit, the light-emitting device is located in the pixel area, and the connection point of the light-emitting device and the driving circuit is located in the interval area and adjacent to the pixel area; the pixel area and the interval area are covered by a planarization layer, the thickness of the planarization layer 30 located in the interval area is T1, the thickness of the planarization layer located in the pixel area is T2, and (T1-T2) / T2≤0.8. The difference between T1 and T2 is not changed, but the ratio of the difference between T1 and T2 to T2 is changed. That is, by simultaneously increasing T1 and T2, when the difference between T1 and T2 is constant, the ratio of the difference to T1 or T2 decreases, thereby reducing the proportion of the expansion difference caused by the difference in the overall expansion of the planarization layer, making the expansion difference between different areas of the planarization layer 30 smaller, preventing film peeling caused by inconsistent expansion between the upper and lower film layers of the planarization layer, and thus reducing the likelihood of appearance defects.

[0082] The display device can also be a television set. When the spacer area is a light-transmitting area, the television display panel can have a transparent effect, allowing users to see objects behind the television.

[0083] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A display panel, characterized in that, It includes a display substrate, a cover plate, pixel areas, and a spacing area connected to the pixel areas; The display panel is provided with a light-emitting device and a driving circuit. The light-emitting device is located in the pixel area, and the connection point between the light-emitting device and the driving circuit is located in the interval area and is located near the pixel area. Laser repair is used to repair defects at the connection point between the light-emitting device and the driving circuit. The pixel area and the interval area are covered by a flattening layer. The thickness of the flattening layer in the interval area is T1, and the thickness of the flattening layer in the pixel area is T2. (T1-T2) / T2≤0.8, 15um≤T1≤19um, 8um≤T2≤12um; The light-emitting device and the driving circuit are disposed on the display substrate, and the planarization layer covers the display substrate and connects the cover plate and the display substrate.

2. The display panel according to claim 1, characterized in that, The planarization layer is an optical adhesive layer.

3. The display panel according to claim 1, characterized in that, The display panel includes a plurality of pixel areas, which are arranged at intervals, with the intervals located between two adjacent pixel areas. One of the pixel areas is configured to display a pixel of the pattern.

4. The display panel according to claim 1, characterized in that, The interval area is a light-transmitting area, through which light can pass from one side of the display panel to the other.

5. The display panel according to claim 4, characterized in that, The area of ​​the interval region is larger than the area of ​​the pixel region.

6. The display panel according to any one of claims 1-5, characterized in that, (T1-T2) / T2≤0.

7.

7. A display device, characterized in that, Includes the display panel as described in any one of claims 1-6.

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