Flexible substrate structure of OLED
By introducing a porous generation layer and an inorganic layer into the flexible OLED substrate structure, the problems of high-temperature damage and mechanical damage during laser lift-off were solved, achieving high-temperature protection and water and oxygen barrier effects for OLED devices.
Patent Information
- Application Number
- CN202323532889.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-25
- Publication Date
- 2025-01-10
- Estimated Expiration
- 2033-12-25
AI Technical Summary
Existing laser peeling technology in flexible OLED displays is prone to uneven energy distribution, peeling damage, and thermal stress release damage. Incomplete PI carbonization leaves residual stress and mechanical damage, and OLED devices are easily damaged by high temperatures.
A flexible substrate structure consisting of a porous generation layer, a PI layer, and an inorganic layer is adopted. The porous generation layer is used to absorb heat and protect the OLED device through a heat-insulating reaction. Local small pores are formed through a decomposition reaction to reduce mechanical peeling force. An inorganic layer is added on the PI layer to improve the water and oxygen barrier effect.
It effectively protects OLED devices from high-temperature damage, reduces mechanical peeling damage, and improves the water and oxygen barrier properties of flexible substrates.
Smart Images
Figure CN222339947U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of display devices, and specifically refers to a flexible substrate structure of an OLED. Background Art
[0002] Organic Light Emitting Diode (OLED) displays have the characteristics of low power consumption, wide viewing angle, wide color gamut, fast response speed, ultra-light and thin, etc. In the high-performance display area, as a self-luminous device, it is developing more and more rapidly. Among them, flexible display technology has become the mainstream in high-end display products. More and more consumers prefer bendable and foldable smart display products, and the displays of such products are mainly flexible AMOLED.
[0003] To realize flexible display, a flexible substrate structure is required. The existing flexible substrate structure is: the flexible OLED display screen uses a flexible PI (polyimide) film as the base substrate attached to the glass. Existing laser lift-off process: The laser lift-off technology (LLO) uses a pulsed laser to be incident from the back of the glass carrier and focused on the interface between the glass carrier and the PI film. Most of the laser energy is absorbed by the PI film at the interface and carbonized and decomposed, and then the PI film is separated from the glass carrier by mechanical peeling.
[0004] Existing laser stripping technology is prone to uneven energy distribution, stripping damage, thermal stress release damage and other defects; if PI carbonization is incomplete, mechanical stripping will easily leave residual stress and mechanical damage on PI, resulting in component leakage or film separation. In addition, when light acts on the film, the highest temperature is not at the interface between glass and PI, and there is a temperature field near the highest temperature where the temperature decreases towards both ends. In order to make the PI material reach the degree of carbonization that can be stripped, the laser action time should also be appropriately extended. Even if decomposition and melting are not achieved during this process, a small amount of heat will still heat the OLED device through heat transfer, causing the OLED device to be damaged by high temperature. Utility Model Content
[0005] The technical problem to be solved by the utility model is to provide a flexible substrate structure of OLED, which utilizes the endothermic reaction of the porous generating layer to block the high temperature generated by the laser acting on PI, thereby protecting the OLED device from being damaged by high temperature.
[0006] The utility model is achieved in this way:
[0007] A flexible substrate structure of an OLED: comprising from bottom to top: a porous generating layer, a PI layer, and an inorganic layer;
[0008] The thickness of the porous generating layer is between 1 and 2 μm;
[0009] The thickness of the PI layer is greater than that of the porous generating layer, and the thickness of the PI layer is between 2 μm and 5 μm.
[0010] The thickness of the inorganic layer is between 0.2 μm and 0.3 μm.
[0011] Furthermore, the inorganic layer is made of one of silicon oxide, silicon nitride or silicon oxynitride.
[0012] The advantages of the utility model are:
[0013] 1. The endothermic reaction of the porous generating layer is utilized to block the high temperature generated by the laser acting on PI, thereby protecting the OLED device from being damaged by high temperature.
[0014] 2. The porous generating layer releases carbon dioxide through decomposition reaction, forming local small pores at the peeling interface, reducing the mechanical peeling force between PI and the glass substrate.
[0015] 3. The inorganic layer above the PI layer enhances the water and oxygen barrier effect of the substrate on the device. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The present invention will be further described below in conjunction with the embodiments with reference to the accompanying drawings.
[0017] Figure 1 It is a schematic structural diagram of the flexible substrate structure of the utility model when it is attached to a plain glass substrate.
[0018] Figure 2 It is a schematic diagram of the flexible substrate structure of the utility model.
[0019] Figure 3 It is a schematic diagram of the high temperature effect produced by the laser acting on the PI layer of the flexible substrate structure of the utility model.
[0020] Figure 4 It is a schematic diagram of the effect of forming local small pores at the peeling interface by decomposing the porous generating layer of the flexible substrate structure of the utility model. DETAILED DESCRIPTION
[0021] like Figure 1 and 2 As shown, a flexible substrate structure of an OLED includes, from bottom to top: a porous generating layer 2, a PI layer 3, and an inorganic layer 4;
[0022] The thickness of the porous generating layer 2 is between 1 and 2 μm;
[0023] The thickness of the PI layer 3 is greater than that of the porous generating layer 2 , and the thickness of the PI layer 3 is between 2 and 5 μm.
[0024] The thickness of the inorganic layer 4 is between 0.2 μm and 0.3 μm.
[0025] During the preparation, a porous generating layer 2, a PI layer 3, and an inorganic layer 4 are formed in sequence on a plain glass substrate 1. Subsequently, TFT and OLED devices need to be prepared on a flexible substrate, and then thin film packaging is performed. The flexible substrate and the TFT and OLED devices thereon are then peeled off from the glass carrier by laser peeling to obtain a flexible OLED panel.
[0026] In this embodiment, the porous generating layer 2 can be realized by adding appropriate additive particles to the polyimide, and stirring to uniformly disperse them in the polyimide solution. The additive should be selected to be a porous generating particle with a reaction temperature between the PI curing temperature and the PI carbonization (or decomposition) temperature, that is, between 350°C and 800°C; for example, carbonate powder (such as magnesium carbonate, calcium carbonate, etc.) is added to the polyimide. The above porous generating particles include but are not limited to carbonates. The porous generating particles do not undergo chemical reactions during the heating and curing process of the polyimide and other post-processes. When the laser acts on the interface between the porous generating layer and the glass, the porous generating particles absorb heat and decompose to release CO2, which can be used for heat insulation during the laser laser process and can reduce the PI peeling resistance during the mechanical peeling process. The thickness of the porous generating layer is between 1 and 2 μm, and the particle size of the porous generating particles is less than 1 μm.
[0027] The material of the PI layer 3 is the same as the polyimide in the porous generating layer 2 , but the thickness is greater than that of the porous generating layer 2 , and is used to isolate the gas in the porous generating layer 2 .
[0028] The material of the inorganic layer 4 can be silicon oxide, silicon nitride or silicon oxynitride, which is used to block water, oxygen or other gases, and its thickness is between 0.2 and 0.3 μm.
[0029] The utility model utilizes the endothermic reaction of the porous generating layer 2 to generate the high temperature (such as Figure 2 The porous generating layer 2 releases carbon dioxide through decomposition reaction, forming local small pores (such as Figure 3 As shown), the mechanical peeling force between the PI layer 3 and the plain glass substrate 1 is reduced. A dense inorganic layer 4 is prepared on the PI layer 3 to enhance the water and oxygen barrier effect of the substrate on the device.
[0030] The above embodiments and drawings do not limit the product form and style of the present utility model. Any appropriate changes or modifications made by ordinary technicians in the relevant technical field should be deemed to be within the patent scope of the present utility model.
Claims
1. A flexible substrate structure of an OLED, characterized in that: From bottom to top, this includes: Porous generating layer, PI layer, inorganic layer; The thickness of the porous generating layer is between 1 and 2 μm; The thickness of the PI layer is greater than that of the porous generating layer, and the thickness of the PI layer is between 2 and 5 μm; The thickness of the inorganic layer is between 0.2 and 0.3 μm.
2. The flexible substrate structure of OLED according to claim 1, characterized in that: The inorganic layer is made of one of silicon oxide, silicon nitride or silicon oxynitride.