WO2020118765A1 - Flexible display panel and manufacturing method therefor - Google Patents

Abstract

A flexible display panel and a manufacturing method therefor. The flexible display panel comprises a flexible substrate (10) and a display function layer (20) disposed on the flexible substrate (10). The flexible substrate (10) contains ultraviolet light absorbing particles (15) of a metal organic framework (MOF) compound. The ultraviolet light absorbing particles (15) can absorb excessive laser energy in an LLO manufacturing process and prevent the same from burning the display function layer (20) on the flexible substrate, thereby effectively improving the yields for the LLO process of a flexible display panel and reducing production costs. The metal organic framework (MOF) compound having an ultra large specific surface area can form a large contact surface between the ultraviolet light absorbing particles and the laser, and thus can achieve good ultraviolet laser absorption without increasing the thickness of the flexible substrate (10), enabling the thinning of a flexible display panel.

Description

Flexible display panel and manufacturing method thereof Technical field

The invention relates to the field of display technology, in particular to a flexible display panel and a manufacturing method thereof.

Background technique

Organic Light Emitting Diode (OLED) display has self-luminous, low driving voltage, high luminous efficiency, short response time, high definition and contrast, close to 180 ° viewing angle, wide temperature range, flexible display and large The area full-color display and many other advantages are recognized by the industry as the most promising display device.

OLED display technology is different from traditional liquid crystal display technology. It does not require a backlight, and uses a very thin organic material coating and glass substrate. When a current passes, these organic materials will emit light. However, because organic materials are easy to react with water vapor or oxygen, as a display device based on organic materials, OLED display screens have very high requirements for packaging. Therefore, the sealing of the OLED device is improved by the packaging of the OLED device, as much as possible with the external environment Isolation is essential for the stable light emission of OLED devices.

For OLED devices, the most competitive advantage is that they can be made into flexible devices, which will bring huge reform changes to the device-related electronics industry. In order to obtain a flexible OLED device, it is first necessary to use a flexible substrate to replace the traditional rigid glass substrate, but from the practical operational considerations, the current industry first chooses to make the flexible substrate on the surface of the rigid glass substrate. Peeling Lift Off (LLO) process peels the flexible substrate from the surface of the glass substrate to achieve the purpose of preparing flexible OLED devices. It can be found from the above description that the LLO process is a key process in the production of flexible OLED devices, and how to effectively improve the yield of the process is extremely critical.

Flexible OLED display adopts flexible substrate (Flexible Substrate) flexible display devices, usually using flexible polyimide (Polyimide, PI) substrate. OLED display panel completes Array and Emission layer on glass substrate Layer) process, began to enter the LLO section, the specific principle is that the bottom glass substrate is irradiated by laser, so that the van der Waals force between the glass substrate and the flexible PI substrate is reversely broken, weakening the force between the glass and the flexible PI substrate, Therefore, the purpose of peeling off the flexible OLED display panel from the glass substrate is achieved.

The principle of the LLO process is: using a 308nm laser to irradiate the glass surface, this energy causes the van der Waals force between the Glass and PI layers to fracture retrogradely, thereby losing the viscosity, and then achieving the separation between Glass and PI. The disadvantage of this method is that because PI has almost no absorption at 308nm wavelength, the laser energy will directly penetrate the buffer layer and be transmitted to the thin film transistor (Thin Film Transistor (TFT) structure, causing burns and affecting the display effect of the device.

In order to solve the above problems, an existing solution is used to prevent the ultraviolet light from damaging the superstructure by doping the buffer layer on the flexible substrate with a material having ultraviolet absorption capability. One of the solutions is to use titanium oxide (TiO ₂ ) particles as ultraviolet absorbing materials. However, the introduction of this "solid" material will inevitably lead to an increase in the thickness of the OLED device, which is contrary to the trend of thinning and thinning of the display panel.

technical problem

The object of the present invention is to provide a flexible display panel, which can effectively improve the yield of the LLO process of the flexible display panel, and is conducive to the thinning of the flexible display panel.

The purpose of the present invention is to provide a method for manufacturing a flexible display panel, which can effectively improve the yield of the LLO process of the flexible display panel, and is conducive to the thinning of the flexible display panel.

Technical solution

To achieve the above object, the present invention provides a flexible display panel, including a flexible substrate and a display function layer provided on the flexible substrate;

The flexible substrate contains ultraviolet light absorbing particles, and the material of the ultraviolet light absorbing particles is a metal organic framework compound.

The ultraviolet light absorbing particles are titanium-containing metal organic framework compounds.

The particle size of the ultraviolet light absorbing particles is 500-700nm;

The specific surface area of the ultraviolet light absorbing particles is greater than 1000 m ² ·g ^-1 .

The maximum absorption light wavelength of the metal organic framework compound is 280-320 nm.

The flexible substrate is a polyimide substrate;

The display function layer includes a buffer layer, a TFT layer, an OLED layer, and a thin-film encapsulation layer that are sequentially stacked on the flexible substrate.

The invention also provides a method for manufacturing a flexible display panel, including the following steps:

Step S1: providing a glass substrate, coating on the glass substrate to form a flexible substrate;

The flexible substrate contains ultraviolet light absorbing particles, and the material of the ultraviolet light absorbing particles is a metal organic framework compound;

Step S2, forming a display function layer on the flexible substrate;

Step S3: Using a laser to scan the glass substrate side of the flexible substrate to separate the flexible substrate from the glass substrate, and peeling off the flexible substrate from the glass substrate.

In the step S1, the ultraviolet light absorbing particles are titanium-containing organic framework compounds.

The particle size of the ultraviolet light absorbing particles is 500-700nm;

The specific surface area of the ultraviolet light absorbing particles is greater than 1000 m ² ·g ^-1 .

The maximum absorption light wavelength of the metal organic framework compound is 280-320nm;

The wavelength of the laser used in step S3 is 308 nm.

The flexible substrate formed in the step S1 is a polyimide substrate;

The display function layer formed in the step S2 includes a buffer layer, a TFT layer, an OLED layer and a thin-film encapsulation layer that are sequentially stacked on the flexible substrate.

Beneficial effect

Beneficial effect of the present invention: A flexible display panel provided by the present invention includes a flexible substrate and a display function layer provided on the flexible substrate. The flexible substrate contains ultraviolet light absorbing particles of a metal organic framework compound, and the ultraviolet light absorbs The particles can absorb the excess laser energy in the LLO process to prevent the excess laser energy in the LLO process from burning the display function layer on the flexible substrate, which can effectively improve the LLO process yield of the flexible display panel, reduce production costs, and have a large ratio The surface area of the metal organic framework compound can form a huge contact surface between the ultraviolet light absorbing particles and the laser, so that it can achieve a better ultraviolet laser absorption effect without increasing the thickness of the flexible substrate, which is conducive to the thinness of the flexible display panel Change. The present invention provides a method for manufacturing a flexible display panel, which is doped with ultraviolet light absorbing particles of a metal organic framework compound in a flexible substrate, the ultraviolet light absorbing particles can absorb excess laser energy in the LLO process and prevent the LLO process Excessive laser energy burns the display function layer on the flexible substrate, which can effectively improve the LLO process yield of the flexible display panel and reduce production costs, and the metal-organic framework compound with a large specific surface area can make ultraviolet light absorb particles and lasers. A huge contact surface is formed between them, so that a good ultraviolet laser absorption effect can be achieved without increasing the thickness of the flexible substrate, which is beneficial to the thinning and thinning of the flexible display panel.

In order to further understand the features and technical content of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings are provided for reference and explanation only, and are not intended to limit the present invention.

BRIEF DESCRIPTION

The technical solutions and other beneficial effects of the present invention will be apparent through the detailed description of the specific embodiments of the present invention with reference to the accompanying drawings.

In the drawings,

1 is a schematic structural diagram of a flexible display panel of the present invention;

2 is a schematic flowchart of a method for manufacturing a flexible display panel of the present invention;

3 is a schematic diagram of step S1 of the method for manufacturing a flexible display panel of the present invention;

4 is a schematic diagram of step S2 of the method for manufacturing a flexible display panel of the present invention;

5-6 are schematic diagrams of step S3 of the method for manufacturing a flexible display panel of the present invention.

Embodiments of the invention

In order to further elaborate on the technical means adopted by the present invention and its effects, the following will describe in detail with reference to the preferred embodiments of the present invention and the accompanying drawings.

Please refer to the picture 1 , The present invention first provides a flexible display panel, including a flexible substrate 10 And on flexible substrate 10 Display function layer 20 ;

The flexible substrate 10 Contains metal-organic framework compounds for absorbing ultraviolet light ( Metal-organic framework , MOF ) UV-absorbing particles 15 , The metal organic framework compound is a porous polymer material with a large specific surface area, so MOF The material's large specific surface area allows ultraviolet light to absorb particles 15 Able to provide a huge contact surface to contact with the laser, so that the flexible substrate 10 Ultraviolet light absorbing particles doped with less metal organic framework compounds 15 At the same time, it can also effectively absorb LLO The excess UV light in the process, and the traditional "solid" UV absorbing materials (such as TiO ₂ ) Compared to the UV-absorbing particles of the metal organic framework compound 15 On flexible substrate 10 The introduction of the internal can ensure the thinness of the flexible display panel while ensuring LLO Yield of the craft.

Specifically, the ultraviolet absorption particles of the metal organic framework compound 15 Has a specific surface area greater than 1000m ² · g ^-1 .

Specifically, the maximum absorption light wavelength of the metal organic framework compound is 280-320nm .

Specifically, the ultraviolet light absorbing particles 15 The material is an organic framework compound containing titanium metal ( Ti-contained metal-organic framework , Ti-MOF ).

Specifically, the titanium-containing metal organic framework compound is obtained by reacting bis(acetylacetonyl) diisopropyl titanate with terephthalic acid under appropriate conditions. The particle size of the titanium-containing metal organic framework compound particles is 500-700nm , Its specific surface area ( Brunauer-Emmett-Teller , BET ) Up to 1364m ² · g ^-1 , And because of titanium ( Ti ) The presence of the element, the titanium-containing organic framework compound in 300nm It has excellent ultraviolet absorption capacity at the left and right, and LLO Laser wavelength used in the process ( 308nm ) To match.

Specifically, the flexible substrate 10 For polyimide ( PI ) Substrate.

Specifically, the display function layer 20 Including sequentially stacked on the flexible substrate 10 Buffer layer twenty one , TFT Floor twenty two , OLED Floor twenty three And film encapsulation twenty four .

Specifically, the buffer layer twenty one Is silicon nitride ( SiNx ) Layer, silicon oxide ( SiOx ) Stack of layers or both.

Specifically, the TFT Floor twenty two Used for the OLED Floor twenty three Row drive, including multiple arrays TFT Device, the TFT The device is low temperature polysilicon ( Low Temperature Poly-silicon , LTPS ) Type, or metal oxide semiconductor ( Metal-Oxide Semiconductor , MOS ) Type, such as indium gallium zinc oxide ( IGZO ) Of metal oxide semiconductor type.

Specifically, the OLED Floor twenty three Including set in the TFT Floor twenty two The first electrode layer on the TFT Floor twenty two And a pixel definition layer on the first electrode layer, an organic functional layer provided on the first electrode layer, and a second electrode layer (not shown) provided 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 An electrode layer and the corresponding second electrode layer above constitute a OLED Device.

Specifically, the first electrode layer and the second electrode layer are used as OLED The anode of the device ( Anode ) And cathode ( Cathode ); The organic functional layer includes a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer that are sequentially arranged from bottom to top.

Specifically, the thin film encapsulation layer twenty four It includes an inorganic barrier layer and an organic buffer layer (not shown) that are stacked.

The flexible display panel and flexible substrate of the present invention 10 Ultraviolet light absorbing particles containing metal organic framework compound for absorbing ultraviolet light 15 , The ultraviolet light absorbing particles 15 Able to LLO Absorb excess laser energy during the process to prevent LLO Excess laser energy burns the flexible substrate during the process 10 Display function layer 20 , Which can effectively improve the flexible display panel LLO Process yield, reduce production costs, and metal-organic framework compounds with large specific surface area can make ultraviolet light absorb particles 15 Form a huge contact surface with the laser, so as not to increase the flexible substrate 10 In the case of thickness, it can also achieve a better ultraviolet laser absorption effect, which is conducive to the thinning of the flexible display panel.

Based on the above flexible display panel, please refer to the figure 2 The present invention also provides a method for manufacturing a flexible display panel, which includes the following steps:

step S1 , As shown 3 As shown, a glass substrate is provided 50 , In the glass substrate 50 Coated to form a flexible substrate 10 .

The flexible substrate 10 Ultraviolet light absorbing particles containing metal organic framework compound for absorbing ultraviolet light 15 , MOF The material's large specific surface area allows ultraviolet light to absorb particles 15 Able to provide a huge contact surface to contact with the laser, so that the flexible substrate 10 Less doped MOF UV-absorbing particles 15 At the same time, it can also effectively absorb LLO The excess UV light in the process, and the traditional "solid" UV absorbing materials (such as TiO ₂ ) Compared to the MOF UV-absorbing particles 15 On flexible substrate 10 The introduction of the internal can ensure the thinness of the flexible display panel while ensuring LLO Yield of the craft.

Specifically, the ultraviolet light absorbing particles 15 Has a specific surface area greater than 1000m ² · g ^-1 .

Specifically, the maximum absorption light wavelength of the metal organic framework compound is 280-320nm .

Specifically, the flexible substrate 10 It is a polyimide substrate.

Specifically, the ultraviolet light absorbing particles 15 It is a titanium-containing organic framework compound.

Specifically, the titanium-containing metal organic framework compound is obtained by reacting bis(acetylacetonyl) diisopropyl titanate with terephthalic acid under appropriate conditions. The particle size of the titanium-containing metal organic framework compound particles is 500-700nm , Its specific surface area can be as high as 1364m ² · g ^-1 , And due to the presence of titanium element, the titanium-containing metal organic framework compound in 300nm It has excellent ultraviolet absorption capacity at the left and right LLO Laser wavelength used in the process ( 308nm ) To match.

step S2 , As shown 4 As shown in the flexible substrate 10 Display function layer 20 .

Specifically, the steps S2 Display function layer 20 Including sequentially stacked on the flexible substrate 10 Buffer layer twenty one , TFT Floor twenty two , OLED Floor twenty three And film encapsulation twenty four .

Specifically, the buffer layer twenty one It is a silicon nitride layer, a silicon oxide layer, or a stack combination of the two.

Specifically, the steps S2 Formed in TFT Floor twenty two Used for the OLED Floor twenty three Row drive, including multiple arrays TFT Device, the TFT The device is a low-temperature polysilicon type or a metal oxide semiconductor type, such as a metal oxide semiconductor type of indium gallium zinc oxide.

Specifically, the OLED Floor twenty three Including set in the TFT Floor twenty two The first electrode layer on the TFT Floor twenty two And a pixel definition layer on the first electrode layer, an organic functional layer provided on the first electrode layer, and a second electrode layer (not shown) provided 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 An electrode layer and the corresponding second electrode layer above constitute a OLED Device.

Specifically, the first electrode layer and the second electrode layer are used as OLED The anode and the cathode of the device; the organic functional layer includes a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer arranged in this order from bottom to top.

Specifically, the thin film encapsulation layer twenty four It includes an inorganic barrier layer and an organic buffer layer (not shown) that are stacked.

step S3 , As shown 5-6 As shown, the laser is applied to the flexible substrate 10 Glass substrate 50 Scan one side to make the flexible substrate 10 With glass substrate 50 Separate the flexible substrate 10 From glass substrate 50 Peel off.

Specifically, the steps S3 The wavelength of the laser used in is 308nm .

The manufacturing method of the flexible display panel of the present invention 10 Ultraviolet light absorbing particles doped with metal organic framework compounds for absorbing ultraviolet light 15 , The ultraviolet light absorbing particles 15 Able to LLO Absorb excess laser energy during the process to prevent LLO Excess laser energy burns the flexible substrate during the process 10 Display function layer 20 , Which can effectively improve the flexible display panel LLO Process yield, reduce production costs, and metal-organic framework compounds with large specific surface area can make ultraviolet light absorb particles 15 Form a huge contact surface with the laser, so as not to increase the flexible substrate 10 In the case of thickness, it can also achieve a better ultraviolet laser absorption effect, which is conducive to the thinning of the flexible display panel.

In summary, the present invention provides a flexible display panel, which includes a flexible substrate and a display function layer provided on the flexible substrate, the flexible substrate contains ultraviolet light absorbing particles of a metal organic framework compound, the ultraviolet light absorbing particles Able to LLO Absorb excess laser energy during the process to prevent LLO Excess laser energy in the process burns the display function layer on the flexible substrate, which can effectively improve the flexible display panel LLO Process yield, reduce production costs, and metal-organic framework compounds with large specific surface area can make a huge contact surface between ultraviolet light absorbing particles and laser, so that it can achieve better without increasing the thickness of the flexible substrate The ultraviolet laser absorption effect is conducive to the thinning of the flexible display panel. The present invention provides a method for manufacturing a flexible display panel. By doping the flexible substrate with ultraviolet light absorbing particles of a metal organic framework compound, the ultraviolet light absorbing particles can LLO Absorb excess laser energy during the process to prevent LLO Excess laser energy in the process burns the display function layer on the flexible substrate, which can effectively improve the flexible display panel LLO Process yield, reduce production costs, and metal-organic framework compounds with large specific surface area can make a huge contact surface between ultraviolet light absorbing particles and laser, so that it can achieve better without increasing the thickness of the flexible substrate The ultraviolet laser absorption effect is conducive to the thinning of the flexible display panel.

As mentioned above, for those of ordinary skill in the art, various other corresponding changes and modifications can be made according to the technical solutions and technical concepts of the present invention, and all such changes and modifications should fall within the protection scope of the claims of the present invention. .

Claims (10)

1. A flexible display panel includes a flexible substrate and a display function layer provided on the flexible substrate;

   The flexible substrate contains ultraviolet light absorbing particles, and the material of the ultraviolet light absorbing particles is a metal organic framework compound.
2. The flexible display panel according to claim 1, wherein the material of the ultraviolet light absorbing particles is a titanium-containing metal organic framework compound.
3. The flexible display panel according to claim 1, wherein the particle diameter of the ultraviolet light absorbing particles is 500-700 nm;

   The specific surface area of the ultraviolet light absorbing particles is greater than 1000 m ² ·g ^-1 .
4. The flexible display panel according to claim 1, wherein the maximum absorption light wavelength of the metal organic framework compound is 280-320 nm.
5. The flexible display panel of claim 1, wherein the flexible substrate is a polyimide substrate;

   The display function layer includes a buffer layer, a TFT layer, an OLED layer, and a thin-film encapsulation layer that are sequentially stacked on the flexible substrate.
6. A method for manufacturing a flexible display panel includes the following steps:

   Step S1: providing a glass substrate, coating on the glass substrate to form a flexible substrate;

   The flexible substrate contains ultraviolet light absorbing particles, and the material of the ultraviolet light absorbing particles is a metal organic framework compound;

   Step S2, forming a display function layer on the flexible substrate;

   Step S3: Using a laser to scan the glass substrate side of the flexible substrate to separate the flexible substrate from the glass substrate, and peeling off the flexible substrate from the glass substrate.
7. The method for manufacturing a flexible display panel according to claim 6, wherein in the step S1, the ultraviolet light absorbing particles are titanium-containing metal organic framework compounds.
8. The method for manufacturing a flexible display panel according to claim 6, wherein the particle diameter of the ultraviolet light absorbing particles is 500-700nm;

   The specific surface area of the ultraviolet light absorbing particles is greater than 1000 m ² ·g ^-1 .
9. The method for manufacturing a flexible display panel according to claim 6, wherein the maximum absorption light wavelength of the metal organic framework compound is 280-320nm;

   The wavelength of the laser used in step S3 is 308 nm.
10. The method for manufacturing a flexible display panel according to claim 6, wherein the flexible substrate formed in step S1 is a polyimide substrate;

    The display function layer formed in the step S2 includes a buffer layer, a TFT layer, an OLED layer and a thin-film encapsulation layer that are sequentially stacked on the flexible substrate.