Display panel and manufacturing method thereof, and display device

Abstract

The embodiment of the present invention discloses a display panel and a manufacturing method thereof, and a display device. The display panel includes a substrate, a substrate layer arranged on the substrate, and a display structure layer arranged on the substrate layer. The display panel is scanned by a laser head so that the substrate layer is peeled off from the substrate. The display panel at least includes: a first scanning area for scanning by the laser head, a second scanning area for scanning by the laser head, and a scanning overlap area formed by partial overlap of the first scanning area and the second scanning area. In the scanning overlap area, the display structure layer only includes metal wiring. By only arranging metal wiring in the scanning overlap area and not arranging thin film transistor devices, the problem of damage to internal thin film transistor devices caused by severe carbonization of the substrate layer can be avoided, thereby improving the process yield of the display panel.

Description

Technical Field

[0001] The present invention relates to the field of display panels, and in particular to a display panel and a manufacturing method thereof, and a display device. Background Art

[0002] The substrate structure of flexible OLED (Organic Light Emitting Diode) panels mostly uses PI (Polyimide Film) as the substrate. PI, as the carrier of the OLED device display module, has high flexibility and is foldable and bendable. When preparing a flexible substrate, a high-precision mechanical platform is required to cooperate with an excimer laser to form a linear light spot through an external light path to scan the OLED module. Under the action of high-energy laser, the PI film layer loses its viscosity and separates from the substrate.

[0003] LLO (Laser Lift off) laser peeling technology is a key technology in the production of flexible OLEDs. The peeling process has an impact on the yield and cost of the product. In the existing technology, flexible screens can be spliced ​​infinitely like rigid screens. Rigid substrates that have not completed LLO are easier to splice, which can reduce the splicing seam. However, due to the larger size of the substrate after splicing, the scanning size of the laser head needs to be designed to be larger, which will increase the cost. If the scan is divided into two times, there will be a scanning overlap area. In the scanning overlap area, the PI is severely carbonized after repeated scanning by the laser head, which can easily cause damage to the internal TFT device and poor wires.

[0004] Therefore, it is necessary to develop a new type of display panel to solve the problem that the display structure in the existing flexible display panel is easily damaged during laser peeling. Summary of the invention

[0005] Embodiments of the present invention provide a display panel and a method for manufacturing the same, which are used to solve the problem that a display structure in an existing flexible display panel is easily damaged during laser lift-off.

[0006] In order to solve the above technical problems, the embodiments of the present invention disclose the following technical solutions:

[0007] On the one hand, a display panel is provided, comprising a substrate, an underlayer arranged on the substrate, and a display structure layer arranged on the underlayer, wherein the display panel is scanned by a laser head so that the underlayer layer is peeled off from the substrate, and the display panel at least comprises: a first scanning area for scanning by the laser head, a second scanning area for scanning by the laser head, and a scanning overlap area formed by partial overlap of the first scanning area and the second scanning area, wherein the display structure layer only comprises metal traces.

[0008] In addition to or as an alternative to one or more of the features disclosed above, the width of the scanning overlap area ranges from 10 um to 100 um.

[0009] In addition to or as an alternative to one or more of the features disclosed above, the metal routing includes a signal line and a scan line.

[0010] In addition to or as an alternative to one or more of the features disclosed above, the substrate is a glass substrate, and the thickness of the glass substrate is in the range of 0.1 mm to 10 mm.

[0011] In addition to or as an alternative to one or more of the features disclosed above, the material of the substrate layer is one or more of polyimide, polyethylene terephthalate and polybutylene terephthalate, and the thickness of the substrate layer is in the range of 1um-2um.

[0012] In addition to one or more of the features disclosed above, or as an alternative, the display structure layer includes a thin film transistor film layer, which is arranged on the substrate layer; an OLED layer, which is arranged on the thin film transistor film layer; a thin film encapsulation layer, which is arranged on the OLED layer; the thin film transistor film layer includes a plurality of thin film transistor devices arranged in an array, and the thin film transistor device is not arranged in the scanning overlap area.

[0013] In addition to or as an alternative to one or more of the features disclosed above, the energy density of the laser of the laser head is 120 mJ / cm 2 ~130mJ / cm 2 .

[0014] In addition to or as an alternative to one or more of the features disclosed above, the display panel is a spliced ​​screen, including at least two display parts, and a splicing seam is provided between the two display parts.

[0015] On the other hand, a preparation method is provided for preparing the display panel involved in the present invention, comprising the following steps: providing a substrate; preparing a substrate layer on the substrate; preparing a display structure layer on the substrate layer to form a display panel; the display panel at least includes a first scanning area, a second scanning area, and a scanning overlap area formed by partial overlap of the first scanning area and the second scanning area, wherein the display structure layer only includes metal wiring in the scanning overlap area; using a laser head to scan a side of the substrate layer close to the substrate so that the substrate layer is peeled off from the substrate, wherein the scanning size of the laser head is smaller than the size of the display panel, the laser head is aligned with the first scanning area for a first scan, and the laser head is aligned with the second scanning area for a second scan.

[0016] On the other hand, a display device is provided, comprising the display panel and a backlight module according to the present invention, wherein the backlight module is located on a side of the substrate layer away from the display structure layer, and is used to provide a backlight source for the display structure layer.

[0017] In addition to or as an alternative to one or more of the features disclosed above, the backlight module includes a plurality of mini LEDs arranged at intervals, and the mini LED spacing ranges from 100um to 2000um.

[0018] One of the above technical solutions has the following advantages or beneficial effects: there is no need to design the scanning size of the laser head to be larger, and only metal routing needs to be set in the scanning overlap area without setting thin-film transistor devices, thereby avoiding the problem of damage to internal thin-film transistor devices caused by severe carbonization of the substrate layer, thereby improving the process yield of the display panel; at the same time, a small-sized laser head can complete the laser peeling process of a larger-sized display panel, reducing the equipment modification cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The technical solutions and other beneficial effects of the present invention will be made apparent by describing in detail the specific embodiments of the present invention in conjunction with the accompanying drawings.

[0020] Figure 1 A schematic cross-sectional structural diagram of a display panel provided in an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of a top view of the structure of a display panel provided by an embodiment of the present invention;

[0022] Figure 3 A flow chart of a method for manufacturing a display panel provided by an embodiment of the present invention;

[0023] Figure 4 A structural schematic diagram of step 41 of the method for manufacturing a display panel provided in an embodiment of the present invention;

[0024] Figure 5 This is a structural schematic diagram of step 42 of the method for manufacturing a display panel provided in an embodiment of the present invention.

[0025] Reference numerals:

[0026] Display panel-100; Substrate-10;

[0027] Substrate layer-20; Display structure layer-30;

[0028] Scanning overlapping area-110; First scanning area-101;

[0029] Second scanning area-102. DETAILED DESCRIPTION

[0030] The specific structural and functional details disclosed herein are merely representative and are for the purpose of describing exemplary embodiments of the present application. However, the present application can be implemented in many alternative forms and should not be interpreted as being limited to only the embodiments set forth herein.

[0031] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0032] See also Figure 1 and Figure 2 , Figure 1 and Figure 2 The schematic diagrams are a cross-sectional structure diagram and a top view structure diagram of a display panel 100 provided in an embodiment of the present invention. The display panel 100 includes a substrate 10 , a base layer 20 and a display structure layer 30 .

[0033] The substrate 10 is a glass substrate with a thickness ranging from 0.1 mm to 10 mm. In other embodiments, the substrate 10 may also be other conventional hard substrates as long as they can support the substrate layer 20 and the display structure layer 30, and no limitation is made here.

[0034] The substrate layer 20 is disposed on the substrate 10. The material of the substrate layer 20 is not limited to PI (polyimide), PET film (polyethylene terephthalate), polybutylene terephthalate (PBT), preferably PI (polyimide). In this embodiment, the substrate layer 20 is made of PI film. On the one hand, the substrate layer 20 made of organic flexible material is mature and more commonly used; on the other hand, the organic flexible material is also more susceptible to damage by laser, which is conducive to the substrate layer 20 to be carbonized to be peeled off more smoothly after carbonization. The thickness range is 1um-2um, preferably 1.3um.

[0035] The PI film is prepared by IJP (inkjet printing). The PI film is formed by inkjet printing PI glue on the substrate 10 by IJP equipment, and then UV curing is performed to form the PI film. The PI glue material includes polymer mixed glues such as polyimide, polyurethane, and block copolymers containing polyurethane units. Since thermal decomposition of polymers such as polyimide requires a large laser power, ultraviolet light (wavelength = 355um) is used for peeling in the subsequent LLO laser peeling step.

[0036] The display structure layer 30 is disposed on the substrate layer 20, and the display structure layer 30 includes a thin film transistor layer, an OLED layer, and a thin film encapsulation layer. The thin film transistor layer is disposed on the substrate layer 20, and the thin film transistor layer is used to drive the OLED layer. The thin film transistor layer includes a plurality of thin film transistor devices arranged in an array, and the thin film transistor device is a low temperature polysilicon (LTPS) type or a metal oxide semiconductor (MOS) type, such as a metal oxide semiconductor type of indium gallium zinc oxide (IGZO).

[0037] The OLED layer is disposed on the thin film transistor film layer. Specifically, the OLED layer includes a first electrode layer disposed on the thin film transistor film layer, a pixel definition layer disposed on the first electrode layer, an organic functional layer disposed on the first electrode layer, and a second electrode layer disposed on the pixel definition layer and the organic functional layer. The pixel definition layer surrounds a plurality of pixel openings arranged in an array on the first electrode layer; the organic functional layer is disposed in the pixel opening; the organic functional layer in each pixel opening, the corresponding first electrode layer below it, and the corresponding second electrode layer above it together constitute an OLED device.

[0038] Specifically, the first electrode layer and the second electrode layer are used as the anode and cathode of the OLED device respectively; the organic functional layer includes a hole injection layer, a hole transport layer, an OLED layer, an electron transport layer and an electron injection layer arranged in sequence from bottom to top. The first electrode layer, the second electrode layer and the organic functional layer can all be formed by evaporation. The invention of the present invention does not lie in the OLED layer, so the OLED layer will not be described in detail.

[0039] The thin film encapsulation layer is disposed on the OLED layer. Specifically, the thin film encapsulation layer includes an inorganic barrier layer and an organic buffer layer stacked. The thin film encapsulation layer often has good water and oxygen isolation performance, thereby preventing water vapor, oxygen, etc. from contacting the display structure layer 30, thereby protecting the display structure layer 30.

[0040] The display panel 100 is scanned by a laser head to peel off the substrate layer 20 from the substrate 10. The laser head scans the side of the substrate layer 20 close to the substrate 10 to carbonize the substrate layer 20. The carbonized substrate layer 20 cannot be attached to the substrate 10, and then the substrate 10 and the substrate layer 20 are separated to obtain the display structure layer 30 attached to the substrate layer 20. Since the thermal decomposition of the substrate layer 20 requires a large laser power, the energy density of the laser head is 120mJ / cm during the subsequent laser head scanning. 2 ~130mJ / cm 2 .

[0041] In this embodiment, the size of the display panel 100 is larger than the scanning size of the laser head. Specifically, the size of the display panel 100 is 1.5 times the scanning size of the laser head. The display panel 100 will be scanned twice by the laser head. Therefore, the display panel 100 includes a first scanning area 101 for scanning by the laser head, a second scanning area 102 for scanning by the laser head, and a scanning overlap area 110 formed by partially overlapping the first scanning area 101 and the second scanning area 102. The width of the scanning overlap area 110 ranges from 10um to 100um. In the scanning overlap area 110, due to the large energy of the laser of the laser head, repeated scanning will cause the substrate layer 20 to be severely carbonized, thereby damaging the thin film transistor device in the display structure layer 30.

[0042] In this embodiment, in the scanning overlap area 110, the display structure layer 30 is only provided with metal wiring, and no thin film transistor is provided, and the metal wiring only includes necessary signal lines and scanning lines. Therefore, it is not necessary to design the scanning size of the laser head to be larger, so that the problem of damage to the internal thin film transistor device caused by severe carbonization of the substrate layer 20 can be avoided, and the process yield of the display panel 100 is improved; at the same time, a small-sized laser head can complete the laser stripping process of a larger-sized display panel 100, reducing the equipment modification cost.

[0043] The display panel 100 may also be a spliced ​​screen, which includes at least two display parts with a splicing seam between the two display parts. When the display panel 100 is a spliced ​​screen, before the step of peeling the substrate 10 and the backing layer 20, the step of cutting the spliced ​​screen into individual display parts is first performed. By irradiating the splicing seam with a laser beam for cutting, the part of the display part other than the substrate 10 is cut into multiple displays and other unnecessary parts. Such cutting can also be performed by a cutter with a fixed blade or a rotating blade instead of irradiating the laser beam. After cutting, the display and other unnecessary parts are fixed on the substrate 10, and then the substrate 10 and the backing layer 20 are peeled off.

[0044] The embodiment of the present invention further provides a manufacturing method for manufacturing the display panel 100 of the present invention. Figure 3 , Figure 3 The present invention is a flow chart of a preparation method, wherein the preparation method comprises steps 1 to 4.

[0045] Step 1: Provide a substrate 10.

[0046] The substrate 10 is a glass substrate with a thickness ranging from 0.1 mm to 10 mm. In other embodiments, the substrate 10 may also be other conventional hard substrates as long as they can support the substrate layer 20 and the display structure layer 30, and no limitation is made here.

[0047] Step 2: Prepare a backing layer 20 on the substrate 10 .

[0048] The substrate layer 20 is disposed on the substrate 10. The material of the substrate layer 20 is not limited to PI (polyimide), PET film (polyethylene terephthalate), polybutylene terephthalate (PBT), preferably PI (polyimide). In this embodiment, the substrate layer 20 is made of PI film. On the one hand, the substrate layer 20 made of organic flexible material is mature and more commonly used; on the other hand, the organic flexible material is also more susceptible to damage by laser, which is conducive to the substrate layer 20 to be carbonized to be peeled off more smoothly after carbonization. The thickness range is 1um-2um, preferably 1.3um.

[0049] The PI film is prepared by IJP (inkjet printing). The PI film is formed by inkjet printing PI glue on the substrate 10 by IJP equipment, and then UV curing is performed to form the PI film. The PI glue material includes polymer mixed glues such as polyimide, polyurethane, and block copolymers containing polyurethane units. Since thermal decomposition of polymers such as polyimide requires a large laser power, ultraviolet light (wavelength = 355um) is used for peeling in the subsequent LLO laser peeling step.

[0050] Step 3: Prepare a display structure layer 30 on the substrate layer 20 .

[0051] The display structure layer 30 is disposed on the substrate layer 20, and the display structure layer 30 includes a thin film transistor layer, an OLED layer, and a thin film encapsulation layer. The thin film transistor layer is disposed on the substrate layer 20, and the thin film transistor layer is used to drive the OLED layer. The thin film transistor layer includes a plurality of thin film transistor devices arranged in an array, and the thin film transistor device is a low temperature polysilicon (LTPS) type or a metal oxide semiconductor (MOS) type, such as a metal oxide semiconductor type of indium gallium zinc oxide (IGZO).

[0052] The OLED layer is disposed on the thin film transistor film layer. Specifically, the OLED layer includes a first electrode layer disposed on the thin film transistor film layer, a pixel definition layer disposed on the first electrode layer, an organic functional layer disposed on the first electrode layer, and a second electrode layer disposed on the pixel definition layer and the organic functional layer. The pixel definition layer surrounds a plurality of pixel openings arranged in an array on the first electrode layer; the organic functional layer is disposed in the pixel opening; the organic functional layer in each pixel opening, the corresponding first electrode layer below it, and the corresponding second electrode layer above it together constitute an OLED device.

[0053] The thin film encapsulation layer is disposed on the OLED layer. Specifically, the thin film encapsulation layer includes an inorganic barrier layer and an organic buffer layer stacked. The thin film encapsulation layer often has good water and oxygen isolation performance, thereby preventing water vapor, oxygen, etc. from contacting the display structure layer 30, thereby protecting the display structure layer 30.

[0054] Step 4: Use a laser head to scan the side of the backing layer 20 close to the substrate 10 to separate the backing layer 20 from the substrate 10 .

[0055] The display panel 100 is scanned by a laser head to peel off the substrate layer 20 from the substrate 10. The laser head scans the side of the substrate layer 20 close to the substrate 10 to carbonize the substrate layer 20. The carbonized substrate layer 20 cannot be attached to the substrate 10, and then the substrate 10 and the substrate layer 20 are separated to obtain the display structure layer 30 attached to the substrate layer 20. Since the thermal decomposition of the substrate layer 20 requires a large laser power, the energy density of the laser head is 120mJ / cm during the subsequent laser head scanning. 2 ~130mJ / cm 2 .

[0056] In this embodiment, the size of the display panel 100 is larger than the scanning size of the laser head. Specifically, the size of the display panel 100 is 1.5 times the scanning size of the laser head. Two scanning steps are required. Therefore, the display panel 100 includes a first scanning area 101 for scanning by the laser head, a second scanning area 102 for scanning by the laser head, and a scanning overlap area 110 formed by partial overlap of the first scanning area 101 and the second scanning area 102.

[0057] Specifically, step 4 includes step 41 and step 42.

[0058] Step 41: Aim the laser head at the first scanning area 101 to perform the first scan.

[0059] See also Figure 4 , Figure 4 It is a structural diagram of step 41.

[0060] Step 42: Align the laser head to the second scanning area 102 to perform a second scan.

[0061] See also Figure 5 , Figure 5 It is a structural diagram of step 42.

[0062] The second scanning area 102 and the first scanning area 101 have an overlapping area, namely, a scanning overlapping area 110, and the width of the scanning overlapping area 110 ranges from 10um to 100um. In the scanning overlapping area 110, due to the high energy of the laser of the laser head, repeated scanning may cause serious carbonization of the substrate layer 20, thereby damaging the thin film transistor device in the display structure layer 30.

[0063] In this embodiment, in the scanning overlap area 110, the display structure layer 30 is only provided with metal wiring, and no thin film transistor is provided, and the metal wiring only includes necessary signal lines and scanning lines. Therefore, it is not necessary to design the scanning size of the laser head to be larger, so that the problem of damage to the internal thin film transistor device caused by severe carbonization of the substrate layer 20 can be avoided, and the process yield of the display panel 100 is improved; at the same time, a small-sized laser head can complete the laser stripping process of a larger-sized display panel 100, reducing the equipment modification cost.

[0064] The display panel 100 may also be a spliced ​​screen, which includes at least two display parts with a splicing seam between the two display parts. When the display panel 100 is a spliced ​​screen, before the step of peeling the substrate 10 and the backing layer 20, the step of cutting the spliced ​​screen into individual display parts is first performed. By irradiating the splicing seam with a laser beam for cutting, the part of the display part other than the substrate 10 is cut into multiple displays and other unnecessary parts. Such cutting can also be performed by a cutter with a fixed blade or a rotating blade instead of irradiating the laser beam. After cutting, the display and other unnecessary parts are fixed on the substrate 10, and then the substrate 10 and the backing layer 20 are peeled off.

[0065] The embodiment of the present invention further provides a display device, including the display panel 100 and a backlight module involved in the embodiment of the present invention. The backlight module is located on a side of the substrate layer 20 away from the display structure layer 30 and is used to provide a backlight source for the display structure layer 30 .

[0066] The backlight module includes a plurality of LEDs arranged at intervals, and the LED spacing ranges from 100um to 2000um. In other embodiments, the LEDs may also be replaced with mini-LEDs or micro-LEDs.

[0067] The backlight module does not have LEDs in the scanning overlap region 110. Since the width of the scanning overlap region 110 is only 10um to 100um, and the LED spacing is 100um to 2000um, the display effect is not affected.

[0068] The above is a detailed introduction to a display panel and a preparation method thereof, and a display device provided in an embodiment of the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present invention. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A display panel comprising a substrate, an underlayer disposed on the substrate, and a display structure layer disposed on the underlayer, wherein the display panel is scanned by a laser head so that the underlayer is peeled off from the substrate, characterized in that: The scanning size of the laser head is smaller than the size of the display panel, and the display panel at least includes: a first scanning area for scanning by the laser head, a second scanning area for scanning by the laser head, and a scanning overlap area formed by partial overlap of the first scanning area and the second scanning area, and in the scanning overlap area, the display structure layer only includes metal wiring; Wherein, the display structure layer includes A thin film transistor film layer, disposed on the substrate layer; An OLED layer, disposed on the thin film transistor film layer; A thin film encapsulation layer, disposed on the OLED layer; The thin film transistor film layer includes a plurality of thin film transistor devices arranged in an array, and the thin film transistor device is not arranged in the scanning overlap area.

2. The display panel according to claim 1, wherein: The width of the scanning overlap area ranges from 10um to 100um.

3. The display panel according to claim 1, wherein: The metal wiring includes signal lines and scan lines.

4. The display panel according to claim 1, wherein: The substrate is a glass substrate, and the thickness of the glass substrate is in the range of 0.1 mm to 10 mm.

5. The display panel according to claim 1, wherein: The material of the substrate layer is one or more of polyimide, polyethylene terephthalate and polybutylene terephthalate, and the thickness of the substrate layer is in the range of 1um-2um.

6. The display panel according to claim 1, wherein: The display panel is a spliced ​​screen, comprising at least two display parts, with a splicing seam between the two display parts.

7. A method for preparing the display panel according to claim 1, characterized in that: The following steps are involved: providing a substrate; Preparing a substrate layer on the substrate; A display structure layer is prepared on the substrate layer to form a display panel; the display structure layer includes a thin film transistor film layer provided on the substrate layer, an OLED layer provided on the thin film transistor film layer, and a thin film encapsulation layer provided on the OLED layer, and the thin film transistor film layer includes a plurality of thin film transistor devices arranged in an array; the display panel includes at least a first scanning area, a second scanning area, and a scanning overlap area formed by partial overlap of the first scanning area and the second scanning area, and in the scanning overlap area, the display structure layer only includes metal wiring, and the thin film transistor device is not arranged in the scanning overlap area; A laser head is used to scan the side of the substrate layer close to the substrate, so that the substrate layer is peeled off from the substrate, wherein the scanning size of the laser head is smaller than the size of the display panel, the laser head is aligned with the first scanning area for a first scan, and the laser head is aligned with the second scanning area for a second scan.

8. A display device, characterized in that: It comprises the display panel and backlight module as described in any one of claims 1 to 6, wherein the backlight module is located on a side of the substrate layer away from the display structure layer, and is used to provide a backlight source for the display structure layer.

9. The display device according to claim 8, wherein: The backlight module includes a plurality of mini LEDs arranged at intervals, and the mini LED interval ranges from 100um to 2000um.

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