CN113629068B - Display panel and preparation method thereof - Google Patents

Abstract

The application discloses a display panel and a preparation method thereof, wherein the display panel comprises a display area and a non-display area surrounding the display area, the non-display area is provided with a crack prevention area, and the display panel comprises a substrate, a functional structure layer, a light-emitting device layer, a slot hole and a film packaging layer. Polyimide with low elastic modulus in the packaging layer is sequentially filled in the slotted holes with different depths in the functional structural layer, so that bending stress can be well released, and the breakage of signal lines caused by repeated bending stress on the panel is avoided.

Description

A display panel and its preparation method

Technical field

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

Background technique

Active matrix organic light-emitting diodes (AMOLEDs) are expected to overtake liquid crystals and become the mainstream choice for next-generation displays due to their high contrast ratio, wide viewing angle, fast response speed and flexibility.

The current folding mobile phone panel technology is developing rapidly. When the panel is subjected to bending reliability testing, the signal line breaks due to the panel being subjected to repeated bending stress, causing abnormal display. Currently, in order to prevent the breakage of the signal line, inorganic The solution is to dig holes in layers and fill them with organic layers.

Please refer to Figure 1. Figure 1 is a schematic structural diagram of a display panel 10 provided in the prior art. The display panel 10 includes a substrate layer 1, an inorganic layer 2, an organic layer 3, a light emitting layer 4, and an encapsulation layer 5. In the inorganic layer 2 Slots 6 are provided, and organic layers 3 are filled in the slots 6 . At present, the effect of the display panel on preventing the breakage of the signal line is not ideal, because the elastic modulus of the organic layer is not much different from that of the inorganic layer, and the bending stress cannot be released well, and the cracks will appear from the display panel. The path extending from the outside to the inside is insufficient and cannot well prevent cracks from extending inwards.

Therefore, it is indeed necessary to develop a new type of display panel to overcome the shortcomings of the existing technology.

Contents of the invention

An object of the present invention is to provide a display panel that can solve the problem in the prior art that signal lines are broken due to repeated bending stress on the display panel.

In order to achieve the above object, the present invention provides a display panel, which includes a display area and a non-display area surrounding the display area. The non-display area has a crack prevention area. The display panel includes a substrate; a functional structural layer located on On the substrate; a light-emitting device layer is provided on the functional structural layer; slots are provided in the crack prevention area, and the slots are provided in the functional structural layer; and a thin film packaging layer is used to encapsulate all The functional structural layer has an organic layer in the thin film encapsulation layer. The organic layer is disposed in the display area and extends to the crack prevention area and is filled in the slots. The functional structural layer has At least one organic film layer, the elastic modulus of the organic layer in the film encapsulation layer is lower than the elastic modulus of the organic film layer in the functional structure layer.

Using the low elastic modulus organic layer in the encapsulation layer to fill the slots in the functional structural layer can better release the bending stress and avoid the breakage of the signal lines caused by repeated bending stress on the panel.

Further, in other embodiments, the functional structure layer includes an active layer; a first metal insulating layer is provided on the active layer and covers the active layer; a first metal layer is provided on On the first metal insulating layer; a second metal insulating layer is provided on the first metal layer and covers the first metal layer; a second metal layer is provided on the second metal insulating layer ; An interlayer dielectric layer is provided on the second metal layer; a source and drain layer is provided on the surface of the interlayer dielectric layer and is connected to the active layer; a flat layer is provided on the source on the drain layer. The elastic modulus of the organic layer in the film encapsulation layer is lower than the elastic modulus of the flat layer in the functional structure layer, which can better release bending stress.

Further, in other embodiments, the slots include slots with different depths, and the slots with different depths extend to different film layers in the functional structure layer.

Filling the slots of different depths in the functional structural layer with the low elastic modulus organic layer can further release the bending stress.

Further, in other embodiments, the depth of the slot close to the display area is greater than the depth of the slot far away from the display area. This arrangement can relieve bending stress to the greatest extent.

Further, in other embodiments, the substrate includes a substrate layer; a buffer layer provided on the substrate layer; the active layer is provided on the buffer layer, and a portion of the buffer layer is exposed on the substrate layer. into the first slot.

Further, in other embodiments, the light-emitting device layer includes a pixel definition layer disposed on the flat layer, and the pixel definition layer has an opening; an anode layer is disposed in the opening and connected with the The source and drain electrodes are connected; the OLED layer is provided on the anode layer; and the cathode layer is provided on the OLED layer.

Further, in other embodiments, the thin film encapsulation layer includes a first inorganic layer disposed on the cathode layer of the display area; a first organic layer disposed on the first first layer of the display area. On the inorganic layer and on the functional structural layer of the crack prevention area, and filled in the slots, the elastic modulus of the first organic layer is lower than the elastic modulus of the flat layer; the second inorganic layer A layer is provided on the first organic layer and extends from the display area to the crack prevention area. The elastic modulus of the first organic layer in the film encapsulation layer is lower than the elastic modulus of the flat layer in the functional structure layer, which can better release bending stress.

Further, in other embodiments, the first organic layer is made of polyimide. The low elastic modulus polyimide in the encapsulation layer is used to fill the slots of different depths in the functional structural layer in sequence, which can better release the bending stress and avoid the signal line damage caused by repeated bending stress on the panel. fracture.

Further, in other embodiments, the flat layer has a protrusion in the crack prevention area, the protrusion includes a first protrusion and a second protrusion, and the second protrusion The first protruding portion is located on a side of the first protruding portion away from the display area, the first protruding portion is in contact with the first organic layer, and the second protruding portion is in contact with the second inorganic layer. catch. The design of arranging the protruding portion of the flat layer in the crack prevention area at the edge can prevent cracks by connecting the protruding portion with the second inorganic layer. The bank-shaped protruding portion can also prevent inkjet printing. The effect of overflow further increases the path for cracks to extend inward.

Further, in other embodiments, there is a slot between the first protruding part and the second protruding part, which increases the crack extension path and prevents the crack from spreading to the display area.

Further, in other embodiments, the height of the second protrusion is greater than the height of the first protrusion. The protrusions of different heights further increase the crack extension path and prevent the crack from spreading to the display area.

Further, in other embodiments, the display panel includes a bending area, and the bending area includes the crack prevention area in the non-display area. By arranging slots in the crack prevention area and filling the slots with low elastic modulus organic layers, breakage of the signal lines caused by repeated bending stress on the panel in the bending area is avoided.

In order to achieve the above object, the present invention also provides a preparation method for preparing the display panel involved in the present invention. The preparation method includes the following steps: preparing a substrate; preparing a functional structural layer on the substrate; preparing a light-emitting device Layer on the functional structure layer; prepare slots in the crack prevention area, the slots are provided in the functional structure layer; prepare a film encapsulation layer to encapsulate the functional structure layer, the film encapsulation layer There is an organic layer in the display area and extends to the crack prevention area and is filled in the slots. The functional structure layer has at least one organic film layer. The film encapsulation The elastic modulus of the organic layer in the layer is lower than the elastic modulus of the organic film layer in the functional structure layer.

In order to achieve the above object, the present invention also provides a display device, including the display panel related to the present invention.

Compared with the existing technology, the beneficial effects of the present invention are: the present invention provides a display panel and a preparation method thereof, using polyimide with low elastic modulus in the encapsulation layer to sequentially fill slots of different depths in the functional structural layer , can better release the bending stress and avoid the breakage of the signal lines caused by repeated bending stress on the panel; and, the design of setting the protruding portion of the flat layer in the second crack prevention area at the edge can both To prevent cracks, the bank-shaped protruding portion can prevent inkjet printing from overflowing, further increasing the path for cracks to extend inward.

Description of the drawings

The technical solutions and other beneficial effects of the present application will be apparent through a detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings.

Figure 1 is a schematic structural diagram of a display panel in the prior art;

Figure 2 is a schematic top structural view of a display panel provided by an embodiment of the present invention;

Figure 3 is a schematic cross-sectional structural diagram of a display panel provided by an embodiment of the present invention;

FIG. 4 is a flow chart of a method for manufacturing a display panel according to an embodiment of the present invention.

Description of the drawings in the background art:

display panel-10;

Substrate-1; Inorganic layer-2;

Organic layer-3; Luminous layer-4;

Encapsulation layer-5; Slot-6;

Description of the drawings in the specific implementation:

Display panel-100; Display area-101;

Non-display area-102; Crack prevention area-103;

First crack prevention zone-1031; Second crack prevention zone-1032;

Substrate-110; Functional structure layer-120;

Light emitting device layer-130; Slot-140;

Thin film encapsulation layer-150; Substrate layer-111;

Buffer layer-112; Active layer-121;

First metal layer-123; First metal insulation layer-122;

second metal layer-125; second metal insulation layer-124;

Interlayer dielectric layer-126; Source and drain layer-127;

Flat layer - 128; First slot - 141;

Second slot - 142; Third slot - 143;

Pixel definition layer-131; Anode layer-132;

OLED layer-133; Cathode layer-134;

Substrate layer-111; Insulating layer-112;

First inorganic layer-151; First organic layer-152;

Second inorganic layer-153; Protrusion-129;

The first protrusion-1291; the second protrusion-1292.

Detailed ways

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

An embodiment of the present invention provides a display device, which includes a display panel 100. Please refer to FIG. 2. FIG. 2 is a schematic structural diagram of a top view of the display panel 100 provided by an embodiment of the present invention. The display panel 100 includes a display area 101 and a surrounding display area. The non-display area 102 of the area 101 has a crack prevention area 103. The area within the dotted line is a bending area. The bending area includes the crack prevention area 103 in the non-display area 102. The crack prevention area in this application is Area 103 is also to prevent the signal lines from breaking due to repeated bending stress on the panel.

Please refer to Figure 3. Figure 3 is a schematic cross-sectional structural diagram of the display panel 100 provided by an embodiment of the present invention. The crack prevention area 103 includes a first crack prevention area 1031 and a second crack prevention area 1032. The second crack prevention area 1032 is located at the A crack prevention area 1031 is located on the side away from the display area. The display panel 100 includes a substrate 110, a functional structure layer 120, a light emitting device layer 130, slots 140 and a thin film encapsulation layer 150.

The substrate 110 extends from the display area to the crack prevention area 103 and includes a substrate layer 111 and a buffer layer 112 provided on the substrate layer 111 .

The functional structural layer 120 is provided on the buffer layer 112. The functional structural layer 120 extends from the display area 101 to the crack prevention area 103. The functional structural layer 120 includes an active layer 121, a first metal insulating layer 122, a first metal layer 123, Two metal insulating layers 124, a second metal layer 125, an interlayer dielectric layer 126, a source and drain layer 127 and a planarization layer 128. Among them, the active layer 121 is provided on the buffer layer 112; the first metal insulating layer 122 is provided on the active layer 121 and covers the active layer 121; the first metal layer 123 is provided on the first metal insulating layer 122; The second metal insulating layer 124 is provided on the first metal layer 123 and covers the first metal layer 123; the second metal layer 125 is provided on the second metal insulating layer 124; the interlayer dielectric layer 126 is provided on the second metal layer 125; the source and drain layer 127 is disposed on the surface of the interlayer dielectric layer 126 and is connected to the active layer 121; the flat layer 128 is disposed on the source and drain layer 127.

The light-emitting device layer 130 is provided on the functional structure layer 120; the light-emitting device layer 130 includes a pixel definition layer 131, an anode layer 132, an OLED layer 133 and a cathode layer 134. Among them, the pixel definition layer 131 is provided on the flat layer 128, and the pixel definition layer 131 has an opening; the anode layer 132 is provided in the opening and is connected to the source and drain layer 127; the OLED layer 133 is provided on the anode layer 132; the cathode Layer 134 is provided on OLED layer 133 .

The slot 140 is provided in the crack prevention area 103. The slot 140 includes a first slot 141, a second slot 142 and a third slot 143. The depth of the first slot 141 is greater than the depth of the second slot 142. The depth of the second slot hole 142 is greater than the depth of the third slot hole 143 . The first slot 141 is provided in the first crack prevention area 1031 and extends from the side of the flat layer 128 away from the substrate 110 through the functional structure layer 120 to the surface of the substrate 110, with part of the buffer layer 112 exposed in the first slot 141; The two slots 142 are provided in the first crack prevention area 1031 and extend from the side of the flat layer 128 away from the substrate 110 to the surface of the first metal insulating layer 122, with part of the first metal insulating layer 122 exposed in the second slots 142; The third slot 143 is provided in the second crack prevention area 1032 and extends from the side of the flat layer 128 away from the substrate 110 to the surface of the second metal insulating layer 124 . Part of the second metal insulating layer 124 is exposed in the third slot 143 .

The thin film encapsulation layer 150 is used to encapsulate the functional structure layer 120 . The thin film encapsulation layer 150 includes a first inorganic layer 151 , a first organic layer 152 and a second inorganic layer 153 . The first inorganic layer 151 is provided on the cathode layer 134 of the display area; the first organic layer 152 is provided on the first inorganic layer 151 of the display area and the functional structure layer 120 of the crack prevention area 103, and is filled in the first slot. 141. In the second slot 142 and the third slot 143; the second inorganic layer 153 is provided on the first organic layer 152 and extends from the display area 101 to the second crack prevention area 1032.

The buffer layer 112 is connected to the first organic layer 152 through the first slot 141, the first metal insulating layer 122 is connected to the first organic layer 152 through the second slot 142, and the second metal insulating layer 124 is connected through the third The slot 143 is connected to the first organic layer 152 , and the elastic modulus of the first organic layer 152 is lower than the elastic modulus of the flat layer 128 .

Please refer to the following table, which shows different film layer materials in the functional layer structure layer and film encapsulation layer and their corresponding test elastic modulus.

The material of the first organic layer 152 is polyimide. Polyimide with a low elastic modulus in the encapsulation layer is used to sequentially fill the slots of different depths in the functional structural layer 120, which can better release the bending stress and prevent the signal lines from appearing due to repeated bending stress on the panel. of fracture.

The flat layer 128 has a protruding portion 129 in the second crack prevention area 1032. The protruding portion 129 includes a first protruding portion 1291 and a second protruding portion 1292. The second protruding portion 1292 is located away from the first protruding portion 1291. On one side of the display area 101, the first protruding portion 1291 is in contact with the first organic layer 152, and the second protruding portion 1292 is in contact with the second inorganic layer 153. The design of providing the protruding portion of the flat layer 128 in the second crack prevention area 1032 at the edge can not only prevent cracks, but also the bank-shaped protruding portion can prevent inkjet printing overflow, further increasing the The inward path of the crack.

There is a third slot 143 between the first protruding part 1291 and the second protruding part 1292, which increases the crack extension path and prevents the crack from spreading to the display area.

The height of the second protruding part 1292 is greater than the height of the first protruding part 1291. The protruding parts of different heights further increase the crack extension path and prevent the crack from spreading to the display area.

An embodiment of the present invention also provides a preparation method for preparing the display panel 100 involved in the present invention. Please refer to FIG. 4 . FIG. 4 is a flow chart of a preparation method of a display panel provided by an embodiment of the present invention. The preparation method includes the following steps. 1-Step 5.

Step 1: Prepare a substrate 110, which extends from the display area 101 to the non-display area 102.

Specifically, step 1 includes step 11-step 12;

Step 11: Provide a glass substrate, prepare a substrate layer 111 on the glass substrate, and extend the substrate layer 111 from the display area 101 to the non-display area 102;

Step 12: Prepare a buffer layer 112 on the substrate layer 111. The buffer layer 112 extends from the display area 101 to the non-display area 102.

Step 2: Prepare a functional structure layer 120 on the substrate 110. The functional structure layer 120 extends from the display area 101 to the non-display area 102.

Specifically, step 2 includes step 21-step 28;

Step 21: Deposit polysilicon on the buffer layer 112, prepare a semiconductor layer pattern through a photolithography process, and form an active layer 121; the thickness of the active layer 121 is

Step 22: Prepare the first metal insulating layer 122 on the active layer 121 and cover the active layer 121;

Step 23: Prepare the first metal layer 123 on the first metal insulation layer 122;

Step 24: Prepare the second metal insulating layer 124 on the first metal layer 123 and cover the first metal layer 123;

Step 25: Prepare the second metal layer 125 on the second metal insulation layer 124;

Step 26: Prepare the interlayer dielectric layer 126 on the second metal layer 125, and use photolithography and dry etching to form interlayer dielectric holes;

Step 27: Deposit the source and drain electrodes on the surface of the interlayer dielectric layer 126 and connect them to the active layer 121 through the interlayer dielectric holes. Use photolithography and wet etching to prepare the source and drain electrode patterns to form the source and drain electrode layers 127;

Step 28: Prepare a flat layer 128 on the source and drain layer 127.

Step 3: Prepare the light emitting device layer 130 on the functional structure layer 120.

Specifically, step 3 includes step 31-step 34;

Step 31: Deposit ITO/Ag/ITO on the source and drain layers to form an anode layer 132;

Step 32: Prepare the pixel definition layer 131 on the flat layer 128, and the pixel definition layer 131 has an opening, and the anode layer 132 is located in the opening;

Step 33: Prepare the OLED layer 133 on the anode layer 132;

Step 34: Prepare the cathode layer 134 on the OLED layer 133.

Step 4: Prepare slots 140 in the crack prevention area. The slots 140 extend from the side of the functional structure layer 120 away from the substrate 110 into the functional structure layer 120 .

Specifically, step 4 includes step 41-step 43;

Step 41: Prepare the first slot 141 in the first crack prevention area 1031, extending from the side of the flat layer 128 away from the substrate 110 through the functional structure layer 120 to the surface of the substrate 110, with part of the buffer layer 112 exposed in the first slot 141 middle;

Step 42: Prepare the second slot 142 in the first crack prevention area 1031, extending from the side of the flat layer 128 away from the substrate 110 to the surface of the first metal insulating layer 122, with a portion of the first metal insulating layer 122 exposed to the second slot. in hole 142;

Step 43: Prepare the third slot 143 in the second crack prevention area 1032, extending from the side of the flat layer 128 away from the substrate 110 to the surface of the second metal insulating layer 124, with a portion of the second metal insulating layer 124 exposed to the third slot. Hole 143.

Step 5: Prepare a thin film encapsulation layer 150 to encapsulate the functional structural layer 120. The thin film encapsulation layer 150 has at least one encapsulation layer disposed in the display area and extending to the crack prevention area and filled in the slots. This encapsulation film layer The modulus of is lower than the modulus of the functional structural layer 120 .

Specifically, step 5 includes step 51-step 53;

Step 51: Prepare the first inorganic layer 151 on the cathode layer 134 of the display area;

Step 52: Use an inkjet printing process to prepare the first organic layer 152 on the first inorganic layer 151 of the display area and the functional structural layer 120 of the crack prevention area 103, and fill the first slots 141 and the second slots. 142 and the third slot 143, the elastic modulus of the first organic layer 152 is lower than the elastic modulus of the functional structural layer 120;

Step 53: Prepare the second inorganic layer 153, which is disposed on the first organic layer 152 and extends from the display area 101 to the second crack prevention area 1032.

Compared with the existing technology, the beneficial effects of the present invention are: the present invention provides a display panel, a preparation method thereof, and a display device, and utilizes low elastic modulus polyimide in the encapsulation layer to successively fill the functional structural layer at different depths. In the slots, the bending stress can be better released and the breakage of the signal lines caused by repeated bending stress on the panel can be avoided; and the design of the protruding portion of the flat layer is provided in the second crack prevention area at the edge. , can not only prevent cracks, but also the bank-shaped protruding portion can prevent inkjet printing from overflowing, further increasing the path for cracks to extend inward.

In the above embodiments, each embodiment is described with its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

The above is a detailed introduction to a display panel, its preparation method, and a display device provided by the embodiments of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only for To help understand the technical solutions and core ideas of this application; those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications Or substitution does not cause the essence of the corresponding technical solution to depart from the scope of the technical solution of each embodiment of the present application.

Claims (7)

1. A display panel comprising a display region and a non-display region surrounding the display region, the non-display region having a crack prevention region, the display panel comprising:

a substrate;

the functional structure layer is arranged on the substrate;

the light-emitting device layer is arranged on the functional structure layer and comprises a pixel definition layer, and the pixel definition layer is positioned in the display area;

a plurality of slots with different depths are arranged in the functional structure layer extending to the crack prevention area, the slots with different depths extend to different film layers in the functional structure layer, and the depth of the slots close to the display area is larger than that of the slots far away from the display area;

the thin film packaging layer is used for packaging the functional structure layer, an organic layer is arranged in the thin film packaging layer, the organic layer is arranged in the display area, extends to the crack prevention area and is filled in the groove hole, at least one organic film layer is arranged in the functional structure layer, and the elastic modulus of the organic layer in the thin film packaging layer is lower than that of the organic film layer in the functional structure layer;

wherein, the film encapsulation layer includes:

a first inorganic layer disposed on the light emitting device layer of the display region and extending to be cut off at an edge position of the display region;

the first organic layer is arranged on the first inorganic layer of the display area and the functional structure layer of the crack prevention area, is filled in the groove hole, and has an elastic modulus lower than that of a flat layer in the functional structure layer;

and a second inorganic layer disposed on the first organic layer and extending from the display region to the crack prevention region.

2. The display panel of claim 1, wherein the functional structural layer comprises:

an active layer;

the first metal insulating layer is arranged on the active layer and coats the active layer;

the first metal layer is arranged on the first metal insulating layer;

the second metal insulating layer is arranged on the first metal layer and coats the first metal layer;

the second metal layer is arranged on the second metal insulation layer;

the interlayer dielectric layer is arranged on the second metal layer;

the source-drain electrode layer is arranged on the surface of the interlayer dielectric layer and is connected with the active layer;

and the flat layer is arranged on the source-drain electrode layer.

3. The display panel according to claim 2, wherein the flat layer has a protrusion in the crack prevention region, the protrusion including a first protrusion and a second protrusion, the second protrusion being located on a side of the first protrusion away from the display region, the first protrusion being connected to the first organic layer, the second protrusion being connected to the second inorganic layer.

4. The display panel of claim 3, wherein the first projection and the second projection have a slot therebetween.

5. The display panel of claim 4, wherein a height of the second protrusion is greater than a height of the first protrusion.

6. The display panel of claim 1, wherein the display panel includes a inflection region that includes the crack prevention region in a region of the non-display region.

7. A method of manufacturing the display panel of claim 1, comprising the steps of:

preparing a substrate;

preparing a functional structure layer on the substrate;

preparing a light emitting device layer on the functional structure layer;

preparing a slot in the crack prevention area, wherein the slot is arranged in the functional structural layer;

preparing a thin film packaging layer for packaging the functional structural layer, wherein the thin film packaging layer is provided with an organic layer, the organic layer is arranged in the display area, extends to the crack prevention area and is filled in the groove hole, the functional structural layer is provided with at least one organic film layer, and the elastic modulus of the organic layer in the thin film packaging layer is lower than that of the organic film layer in the functional structural layer;

wherein, the film encapsulation layer includes:

a first inorganic layer disposed on the light emitting device layer of the display region and extending to be cut off at an edge position of the display region;

the first organic layer is arranged on the first inorganic layer of the display area and the functional structure layer of the crack prevention area, is filled in the groove hole, and has an elastic modulus lower than that of a flat layer in the functional structure layer;

and a second inorganic layer disposed on the first organic layer and extending from the display region to the crack prevention region.