CN118159101A - Display panel, preparation method thereof and display device - Google Patents

Abstract

The application discloses a display panel, a preparation method thereof and a display device. The display panel includes: the display device comprises a substrate, a display area and a peripheral area, wherein the substrate is provided with the display area and the peripheral area is positioned at the periphery of the display area; the packaging film layer is positioned on the substrate and used for sealing the light-emitting device positioned in the display area, the packaging film layer comprises an inorganic film layer and an organic film layer, the inorganic film layer closest to the light-emitting device is provided with a buffer layer between the inorganic film layer and the organic film layer, the buffer layer covers the edge of the inorganic film layer positioned in the peripheral area and extends to the substrate to be in contact with the substrate, and the organic film layer covers the surface of one side of the buffer layer, which is away from the substrate. The display panel can rely on the buffer layer to promote the packaging effect of the packaging film layer, and can realize reliable packaging under the condition of narrow frames.

Description

Display panel, preparation method thereof and display device

Technical Field

The application relates to the technical field of display, in particular to a display panel, a preparation method thereof and a display device.

Background

In recent years, with the pursuit of a screen ratio by users, a narrow-edge design product based on an OLED is greatly promoted in the market. Narrowing the bezel can enhance the display effect of the display panel, but also leads to a sharp rise in the difficulty of packaging the panel, particularly thin film packaging (TFE packaging). Because the reserved area of the frame is extremely small, the extension length of the packaging film layer at the edge of the substrate is extremely limited, so that the product with a part of extremely narrow frame is difficult to meet the requirements in the stage of reliability test, and the product has a large risk of packaging failure after being used for a period of time.

Therefore, the current display panel, particularly the display panel with a narrow frame, the manufacturing method thereof and the display device still need to be improved.

Disclosure of Invention

The present invention aims to alleviate or even solve at least one of the above mentioned technical problems to at least some extent.

In one aspect of the present application, a display panel is provided. The display panel includes: comprising the following steps: the display device comprises a substrate, a display area and a peripheral area, wherein the substrate is provided with the display area and the peripheral area is positioned at the periphery of the display area; the packaging film layer is positioned on the substrate and used for sealing the light-emitting device positioned in the display area, the packaging film layer comprises an inorganic film layer and an organic film layer, the inorganic film layer closest to the light-emitting device is provided with a buffer layer between the inorganic film layer and the organic film layer, the buffer layer covers the edge of the inorganic film layer positioned in the peripheral area and extends to the substrate to be in contact with the substrate, and the organic film layer covers the surface of one side of the buffer layer, which is away from the substrate.

According to an embodiment of the application, an optical cement is provided between the buffer layer and the organic film layer.

According to the embodiment of the application, a touch control film layer is further arranged between the organic film layer and the inorganic film layer, and the optical adhesive covers the buffer layer and the touch control film layer.

According to an embodiment of the present application, the inorganic film layer extends from the display region to the peripheral region, and the inorganic film layer has a step between an edge in the peripheral region and the substrate, a ratio of a height of the step to a thickness of the inorganic film layer being 0.3 to 1.

According to an embodiment of the present application, a length of a portion of the buffer film layer in contact with the substrate is 0.5 to 2mm in a direction from an edge of the inorganic film layer in the peripheral region toward the edge of the substrate.

According to an embodiment of the present application, the display panel further includes at least one barrier dam, the inorganic film layer includes a first inorganic layer and a second inorganic layer, the organic film layer includes a first organic layer between the first inorganic layer and the second inorganic layer, and a second organic layer on a side of the second inorganic layer facing away from the substrate, the first inorganic layer covers the barrier dam, an edge of the first organic layer extends to one of the barrier dams, the second inorganic layer covers the first organic layer, and a portion of the first inorganic layer not covered by the first organic layer, the second organic layer covers the second inorganic layer, and the buffer layer is between the second inorganic layer and the second organic layer.

In another aspect of the present application, a method of manufacturing the aforementioned display panel is provided. The method comprises the steps of forming an encapsulation film layer on a substrate and sealing a light emitting device located in the display area, wherein the encapsulation film layer comprises an inorganic film layer and an organic film layer, a buffer layer is arranged between the inorganic film layer closest to the light emitting device and the organic film layer, and the organic film layer covers the surface of one side, away from the substrate, of the buffer layer.

According to an embodiment of the application, the method comprises: sequentially forming a first inorganic layer, a first organic layer and a second inorganic layer, and etching to remove part of the first inorganic layer and the second inorganic layer extending to the peripheral area so as to form a step difference between the edge of the inorganic film layer and the substrate; forming the buffer layer and enabling the buffer layer to cover the edge at the level difference; a second organic layer is formed.

According to an embodiment of the present application, before the second organic layer is formed, the method further includes a step of providing a touch film layer, and providing an optical adhesive covering the touch film layer.

In yet another aspect, the present application provides a display device. The display device comprises a display panel as described above or prepared using the method described above.

Drawings

The foregoing and/or additional aspects and advantages of the application will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

fig. 1 shows a schematic structure of a display panel according to an embodiment of the present application;

FIG. 2 is a schematic view showing the edge of a display panel during the process of preparing an inorganic film layer according to the related art;

FIG. 3 is a schematic view showing a structure of a display panel according to the related art;

FIG. 4 is a schematic view showing the structure of another display panel according to the related art;

FIG. 5 is a schematic diagram showing a path of peeling of the encapsulation film layer in the related art;

Fig. 6 shows a schematic structure of a display panel according to an embodiment of the present application.

Detailed Description

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. All patents and publications referred to herein are incorporated by reference in their entirety. The terms "comprising" or "including" are used in an open-ended fashion, i.e., including the teachings described herein, but not excluding additional aspects.

In the description of the present application, all numbers disclosed herein are approximate, whether or not words of "about" or "about" are used. The numerical value of each number may vary by less than 10% or reasonably as considered by those skilled in the art, such as 1%, 2%, 3%, 4% or 5%.

In one aspect of the present application, referring to fig. 1, a display panel is provided. The display panel includes a substrate 100 having a display area thereon, and a peripheral area (only the peripheral area is shown) located at the periphery of the display area. The encapsulation film layer is disposed on the substrate 100 for sealing the light emitting device disposed in the display area, and preventing the film layer of the light emitting device from being corroded by water oxygen in the environment. The encapsulation film layer includes an inorganic film layer 210 and an organic film layer 220, the inorganic film layer closest to the light emitting device, as shown in the figure with a buffer layer 300 between the organic film layer 220 and the inorganic film layer 210. The buffer layer 300 covers the edge of the inorganic film layer 210 located in the peripheral region and extends to the substrate 100 to be in contact with the substrate, and the organic film layer 220 covers the surface of the buffer layer 300 on the side facing away from the substrate 100. The display panel can improve the packaging effect of the packaging film layer by virtue of the buffer layer 300, and can realize reliable packaging under the condition of a narrow frame.

For easy understanding, the principle by which the display panel can achieve the above-described advantageous effects is first described briefly below:

Referring to fig. 2 through 5, the package structure, particularly the thin film package, is typically formed of a stack of multiple inorganic, organic film layers. The inorganic film layer is formed by adopting a deposition mode. Referring to fig. 2, in performing film deposition, such as using Chemical Vapor Deposition (CVD) of an inorganic film, a pattern of a plating film region needs to be formed using a metal template (Mask). However, a gap (shown at Mask on the left in fig. 2) remains between the metal template and the glass surface, and the gap has a large difference in height from the height at which the Gas is movable in the normal deposition position (shown at Gas on the right in fig. 2), so that the Gas composition, the Gas flow direction, the electric field strength, and the electrode spacing at the gap are all affected, and the change which is not controlled by the expectation occurs. Therefore, in the area, the film quality (Ri), thickness and adhesion of the formed film layer are greatly different from those of the normal film coating area. Thus, at the edges of the deposited inorganic film, it is difficult to maintain a uniform thickness of the bulk portion of the inorganic film, as shown in fig. 2, where the thickness of the film varies significantly near the edges of the substrate, where the thickness of the film gradually drops to 50% of the desired thickness (50% thk) at the Mask edge, forming a "Shadow zone" (Shadow), where some of the gas still enters the metal template covered portion, forming a "tailing" zone (UMC) of the inorganic film. Therefore, as shown in fig. 3, the structure of the finally formed encapsulation film layer forms an inclined slope at the edges of the substrate 100, the first and second inorganic layers 210A and 210B. The above structure results in poor CVD rub-out quality and adhesion in the "tailing" area (UMC), and thus in some cases, especially in narrow-frame products, water oxygen, particle impurities, etc. in the environment can invade the display area inside the panel through the "path" formed by the inclined surfaces. In particular, in some cases, it is also necessary to fix structures including, but not limited to, a touch module and the like between the organic film layer 220 and the inorganic layers (the first inorganic layer 210A, the second inorganic layer 210B) by the optical adhesive 400 and the like. The optical cement 400, and in particular the better performing optical cement, will have a greater stress after drying (as shown by the shear head in fig. 3). Moreover, once the inorganic film layer generates cracks, organic matters of the organic film layer 220 also enter the product along the cracks, and aggregate. After entering the cracks, the moisture in the environment can also cause the aggregated organic matters to expand, and finally the packaging film layer is broken. These various conditions can cause the inorganic film to be easily peeled off along the surface of the substrate 100 at the slope, as indicated by the arrows in fig. 4 and 5, and thus cause the package to fail.

The buffer layer 300 is arranged above the inorganic layer which is easy to be stripped in the peripheral area, and the buffer layer 300 extends to the surface of the substrate 100 and is contacted with the substrate, so that a film layer which can be contacted with the substrate 100 can be arranged between the organic layer and the inorganic layer. The buffer layer 300 may block the initiation site of the inorganic layer peeling (as shown at the arrow in fig. 4) using a portion in contact with the substrate. Further, this structure is applicable to display panel products having ultra-narrow frames, and the purpose of the portion where the buffer layer 300 and the substrate 100 are in direct contact is to block the starting point of peeling of the inorganic layer, so that the buffer layer 300 and the substrate 100 may be in direct contact in the frame region.

Referring to fig. 6, there is an optical cement 400 between the buffer layer 300 and the organic film layer according to an embodiment of the present application. The touch film 500 is further included between the organic film and the inorganic film, and the optical cement 400 covers the buffer layer 300 and the touch film 500. In some examples, the stacking order of the buffer layer 300 and the touch film layer 500 is not particularly limited as long as a portion where the buffer layer 300 and the substrate 100 are in direct contact can be ensured. For example, the buffer layer 300 and the touch film layer 500 may be located in the same layer, or both may be stacked in the stacking order as shown in fig. 6, or in other order. The optical cement 400 covers the buffer layer 300 and the touch film layer 500 to achieve fixation and adhesion of the touch film layer 500. The specific structure of the touch film 500 is not particularly limited, and for example, a touch electrode formed of a metal mesh supported on a flexible substrate may be used as the touch film.

According to an embodiment of the present application, in order to further improve the package reliability of the display panel, an inorganic film layer having poor deposition quality as shown in fig. 2 may be removed. Thus, on the one hand, sufficient adhesion between the inorganic film layer and the substrate 100 can be ensured, and on the other hand, "step" can be formed at the edge of the inorganic film layer, blocking the peeling path as shown in fig. 5.

Specifically, referring to fig. 6, the inorganic film layers, such as the first inorganic film layer 210A and the second inorganic film layer 210B shown in the drawings, may extend from the display region to the peripheral region, and form a step between the substrate and the edge within the peripheral region. Thus, the buffer layer 300 covering the first inorganic film layer 210A and the second inorganic film layer 210B may also cover the step, i.e., the sidewalls of the edges of the first inorganic film layer 210A and the second inorganic film layer 210B. By means of the step difference, the transmission path of substances such as water, oxygen and the like can be further blocked, so that the packaging effect is improved, and the probability of passing the reliability test is improved. According to a specific example of the present application, the height of the step is not particularly limited as long as it can be ensured that the formed buffer layer 300 can be kept continuous at the step. For example, in some specific examples, the ratio of the height of the step to the inorganic film thickness is 0.3-1, more specifically, 0.3,0.4,0.5,0.6,0.8 or 1 may be used. The ratio of the height of the step to the thickness of the inorganic film layer is 1, namely the height of the step is the thickness of the inorganic film layer. That is, all of the inorganic film layers of the UMC and Shadow regions as shown in fig. 2 may be removed.

According to an embodiment of the present application, the length of the portion where the buffer film layer and the substrate are in contact is 0.5-2mm in a direction from the edge of the inorganic film layer in the peripheral region toward the edge of the substrate, such as where the sidewalls of the first inorganic film layer 210A and the second inorganic film layer 210B form a step. It will be appreciated by those skilled in the art that in some types of display panels, particularly narrow or ultra-narrow bezel display panels, the removal of a specific portion of the inorganic film layer edge "tailing" region, and the height of the step formed and the length of buffer layer 300 that can be in direct contact with substrate 100 are related. The more UMC regions removed, the higher the level of step formed, and the longer the buffer layer 300 can be in direct contact with the substrate 100, the better the ability to mitigate package failure. However, the longer the buffer layer 300 can be in direct contact with the substrate 100, the wider the frame.

Therefore, a person skilled in the art can set the portion of the inorganic film layer to be removed according to the specific requirement of the display panel, so as to form a display panel with moderate height of the step, moderate length of the buffer layer 300 capable of being directly contacted with the substrate 100 and narrower frame on the premise of ensuring the packaging effect.

According to embodiments of the present application, the display panel may include other structures such as a back plane circuit structure, a pixel defining layer, and a barrier rib at a peripheral region, etc. which are present in the remaining conventional display panel. In one example, the display panel may have a back plane circuit layer 110 as shown in fig. 4, such as inter-layer dielectric layers and passivation layers, etc., a flattening back layer 120, and a pixel junction defining layer 130. In the peripheral area of the display panel, a barrier dam 10 as shown in fig. 4 may be provided, and for example, at least one barrier dam 10 may be further included. The inorganic film layer may specifically include a first inorganic layer 210A and a second inorganic layer 210B, and the organic film layer includes a first organic layer 220 between the first inorganic layer and the second inorganic layer, and a second organic layer 220B on a side of the second inorganic layer facing away from the substrate. The first inorganic layer covers the barrier dams, the edge of the first organic layer extends to one of the barrier dams, the second inorganic layer covers the first organic layer 220 and the portion of the first inorganic layer not covered by the first organic layer, and the second organic layer covers the second inorganic layer. The buffer layer may be located between the second inorganic layer and the second organic layer. In some specific examples, the display panel may be an extremely narrow bezel display panel, and may have only one barrier dam.

In another aspect of the present application, a method of manufacturing the foregoing display panel is provided. The method includes the steps of forming an encapsulation film layer on a substrate and sealing the light emitting device located in a display area, the encapsulation film layer including an inorganic film layer and an organic film layer, the method including disposing a buffer layer between the inorganic film layer closest to the light emitting device and the organic film layer, and causing the organic film layer to cover a surface of the buffer layer facing away from a side of the substrate. Therefore, the display panel can be obtained simply and conveniently, and the display panel is ensured to have better packaging effect.

According to an embodiment of the application, the method may comprise: sequentially forming a first inorganic layer, a first organic layer and a second inorganic layer, and etching to remove part of the first inorganic layer and the second inorganic layer extending to the peripheral area so as to form a step difference between the edge of the inorganic film layer and the substrate; forming a buffer layer, and enabling the buffer layer to cover the edge of the step difference; a second organic layer is formed.

According to an embodiment of the present application, before forming the second organic layer, the method further includes a step of disposing a touch film layer and disposing an optical adhesive covering the touch film layer.

For example, according to one specific example of the application, the method may comprise the steps of:

After the fabrication of the back plane circuit and the light emitting element is completed, the first inorganic layer may be fabricated by processes including, but not limited to, chemical Vapor Deposition (CVD), and the first organic layer may be fabricated by processes including, but not limited to, inkjet printing. The deposition of the second inorganic layer is then carried out to form a two-layer inorganic layer stack structure in the edge region.

Subsequently, the UMC region as shown in fig. 2 may be removed by dry etching, forming a level difference between the substrate and the inorganic film layer.

Subsequently, a buffer layer and other functional film layers, such as a touch film layer, are prepared. And the buffer layer covers the side wall of the etched inorganic film layer and is directly contacted with the substrate.

Finally, optical gums are formed, and the second organic layer is prepared, using processes including, but not limited to, conventional processes.

In yet another aspect, the present application provides a display device. The display device comprises a display panel, which is described above. Thus, the display device has all the features and advantages described above, and will not be described in detail herein. In general, the display device has the advantages of high brightness, good display effect at the pixel edge, and the like.

It will be appreciated by those skilled in the art that in the above-described method of the specific embodiment, the written order of steps is not meant to imply a strict order of execution but rather should be construed according to the function and possibly inherent logic of the steps.

It should be noted that, the foregoing descriptions of the various embodiments are intended to emphasize the differences between the various embodiments, and the same or similar features may be referred to each other for brevity and will not be repeated herein.

In the description of the application, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, and may also include the first and second features not being in direct contact but being in contact with each other by another feature therebetween.

In the description of the application, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature.

In the description of the present specification, reference to the term "one embodiment," "another embodiment," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

While embodiments of the present application have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the application, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the application.

Claims (10)

1. A display panel, comprising:

The display device comprises a substrate, a display area and a peripheral area, wherein the substrate is provided with the display area and the peripheral area is positioned at the periphery of the display area;

The packaging film layer is positioned on the substrate and used for sealing the light-emitting device positioned in the display area, the packaging film layer comprises an inorganic film layer and an organic film layer,

The inorganic film layer closest to the light emitting device and the organic film layer are provided with a buffer layer therebetween, the buffer layer covers the edge of the inorganic film layer in the peripheral area and extends to the substrate to be in contact with the substrate, and the organic film layer covers the surface of the buffer layer on one side facing away from the substrate.

2. The display panel of claim 1, wherein an optical adhesive is provided between the buffer layer and the organic film layer.

3. The display panel according to claim 2, further comprising a touch film layer between the organic film layer and the inorganic film layer, wherein the optical paste covers the buffer layer and the touch film layer.

4. A display panel according to claim 3, wherein the inorganic film layer extends from the display region to the peripheral region, and the inorganic film layer has a step between an edge in the peripheral region and the substrate, a ratio of a height of the step to a thickness of the inorganic film layer being 0.3-1.

5. The display panel according to claim 1, wherein a length of a portion of the buffer layer in contact with the substrate is 0.5 to 2mm in a direction from an edge of the inorganic film layer in the peripheral region toward an edge of the substrate.

6. The display panel of claim 1, further comprising at least one barrier dam, wherein the inorganic film layer comprises a first inorganic layer and a second inorganic layer, wherein the organic film layer comprises a first organic layer between the first inorganic layer and the second inorganic layer, and a second organic layer on a side of the second inorganic layer facing away from the substrate,

The first inorganic layer covers the barrier dams, the edge of the first organic layer extends to one of the barrier dams, the second inorganic layer covers the first organic layer, and a portion of the first inorganic layer not covered by the first organic layer covers the second inorganic layer, and the buffer layer is located between the second inorganic layer and the second organic layer.

7. A method of manufacturing the display panel of any one of claims 1 to 6, comprising the steps of forming an encapsulation film layer on a substrate and sealing a light emitting device located in the display region,

The packaging film layer comprises an inorganic film layer and an organic film layer, the method comprises the steps of arranging a buffer layer between the inorganic film layer closest to the light-emitting device and the organic film layer, and enabling the organic film layer to cover the surface of one side, away from the substrate, of the buffer layer.

8. The method according to claim 7, characterized in that the method comprises:

Sequentially forming a first inorganic layer, a first organic layer and a second inorganic layer, and etching to remove part of the first inorganic layer and the second inorganic layer extending to the peripheral area so as to form a step difference between the edge of the inorganic film layer and the substrate;

forming the buffer layer and enabling the buffer layer to cover the edge at the level difference;

A second organic layer is formed.

9. The method of claim 8, further comprising the step of disposing a touch film layer and disposing an optical adhesive covering the touch film layer prior to forming the second organic layer.

10. A display device comprising a display panel, the display panel being as claimed in any one of claims 1 to 6 or being manufactured by the method of any one of claims 7 to 9.