A method of organic light emitting diode substrate lift-off

Abstract

A kind of method for stripping organic light emitting diode substrate, substrate structure includes glass substrate, PET protective layer, first PI protective layer, TFT drive layer, RGB luminescent layer, second PI protective layer and linear polarizing layer;The method for stripping substrate includes the following steps: first, PET protective layer is stripped by laser;Second, laser is stripped by cooperating main laser and auxiliary laser;Third, the pulse width, pulse energy, wavelength selected by main laser and auxiliary laser are different;When stripping, laser beam is irradiated from the glass base bottom of glass substrate, the focus of laser acts on different positions of PET protective layer, when PET protective layer is completely gasified or critical gasification, stripping is realized.The present application uses two different lasers with femtosecond level pulse width, and is used to realize smaller heat-affected range, guarantee the ablation gas pressure impact effect of stripping layer with only micron level thickness, realize large-area, non-damage, no residue high yield laser stripping.

Description

Technical Field

[0001] This invention belongs to the field of organic light-emitting diode (OLED) technology, and specifically relates to a method for peeling off an organic light-emitting diode substrate. Background Technology

[0002] Organic light-emitting diodes (OLEDs, also known as organic electroluminescent displays or organic light-emitting semiconductors) have a basic structure after being grown on a glass substrate, as shown below. Figure 2 The typical method of separation is to irradiate the bottom of the substrate with a nanosecond rectangular laser beam to vaporize the polyimide (PI) layer, thereby separating the substrate from the OLED device.

[0003] One existing technology involves using ultraviolet excimer lasers or solid-state lasers with pulse widths on the order of nanoseconds as the exfoliation laser source, with laser energy densities typically around 10² mJ / cm². 2 Within a certain order of magnitude, laser ablation can guarantee the effectiveness of films with thicknesses on the order of tens of micrometers, while reducing ablation damage caused by laser thermal effects. However, it suffers from four drawbacks: First, laser thermal effects easily cause ablation damage; second, the energy density of the output beam is uneven, leading to incomplete ablation; third, laser irradiation thermal stress can cause release damage; and fourth, unabsorbed laser light can directly irradiate the OLED device, affecting its lifespan and performance. Therefore, it is necessary to design a new method for ablation of organic light-emitting diode substrates to address these issues. Summary of the Invention

[0004] The main objective of this invention is to provide a method for peeling off an organic light-emitting diode substrate, in order to solve at least one technical problem existing in the prior art.

[0005] To achieve the above objectives, a method for peeling off an organic light-emitting diode substrate is proposed, wherein the substrate structure includes a glass substrate;

[0006] A PET protective layer (polyethylene terephthalate, abbreviated as PET) is disposed on the glass substrate;

[0007] A first PI protective layer is disposed on the PET protective layer;

[0008] A TFT driving layer (Thin Film Transistor) is disposed on the first PI protective layer;

[0009] An RGB light-emitting layer disposed on the TFT driving layer;

[0010] A second PI protective layer is disposed on the RGB light-emitting layer;

[0011] Linear polarizing layer disposed on the second PI protective layer;

[0012] The method for peeling off the substrate includes the following steps:

[0013] S1: The PET protective layer is peeled off by laser;

[0014] S2: The laser is used for stripping by the cooperation of the main laser and the auxiliary laser;

[0015] S3: The main laser and the auxiliary laser have different pulse widths, pulse energies, and wavelengths. During peeling, a laser beam is used to irradiate the bottom of the glass substrate of the glass substrate. The focus of the laser acts on different positions of the PET protective layer. The PET protective layer is the first to receive the laser energy. When the PET protective layer is completely vaporized or critically vaporized, peeling is achieved.

[0016] Preferably, the laser mentioned in step S1 is a femtosecond ultrafast laser. Irradiation is performed using a femtosecond ultrafast laser with a wavelength range of 100-1200 nm, a pulse width of 500 fs-1 ps, and an energy density of 80-160 mJ / cm². 2 With a repetition frequency of 1-200MHz and a scanning speed of 10-1000mm / s, the femtosecond ultrafast laser makes the particles generated when the femtosecond ultrafast laser interacts with the PET layer material finer, thereby reducing the corresponding damage to the heat-affected zone and surrounding materials.

[0017] Preferably, the beam emitted by the femtosecond ultrafast laser is a circular focused beam. By using the circular focused beam for stripping, the vaporization region can be better controlled and selected.

[0018] Preferably, the femtosecond ultrafast laser is used for cold processing.

[0019] Preferably, in step S2, the main laser and the auxiliary laser form an adjustable angle of 0-60°.

[0020] Preferably, in step S2, the diameter of the main laser spot is 50 μm, and the diameter of the secondary laser spot is less than 10 μm. The main laser performs the stripping action, and the secondary laser performs supplementary stripping on the incompletely stripped areas.

[0021] Preferably, the first PI protective layer is disposed on top of the PET protective layer, and the laser is prevented from entering the OLED device by utilizing the different light absorption rates of different materials.

[0022] Preferably, the glass substrate is a transparent substrate, and the material of the glass substrate is a transparent rigid material through which light beams can pass.

[0023] Preferably, the thickness of the PET protective layer is 10-50 μm.

[0024] Preferably, the release material of the PET protective layer includes, but is not limited to, polybutylene terephthalate, polyethylene naphthalate, polyethersulfone, polyetherimide, polycarbonate, and polyphenylene sulfide.

[0025] The beneficial effects of this invention are:

[0026] 1. An additional protective layer (sacrificial layer) is added to the original organic light-emitting diode device structure, which can effectively block the radiation damage of laser energy fluctuations to the functional layer.

[0027] 2. Two different lasers, a main laser and a secondary laser, with pulse widths in the femtosecond range, are used together to achieve a smaller heat-affected zone, ensuring the ablation gas pressure impact effect of the peeling layer with a thickness on the order of micrometers, and achieving high-yield laser peeling with large area, no damage, and no residue. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of Embodiment 1 of the peeling structure of the organic light-emitting diode substrate described in this invention;

[0029] Figure 2 This is a schematic diagram of the overall structure of the peeling structure of the organic light-emitting diode substrate described in this invention;

[0030] Figure 3 This is a schematic diagram of Embodiment 2 of the peeling structure of the organic light-emitting diode substrate described in this invention;

[0031] In the figure: 1. Glass substrate; 2. PET protective layer; 3. First PI protective layer; 4. TFT driving layer; 5. RGB light-emitting layer; 6. Second PI protective layer; 7. Linear polarizing layer; 8. Main laser; 9. Secondary laser; 10. PBT layer (PBT is an abbreviation for polybutylene terephthalate, also known as polytetramethylene terephthalate). Detailed Implementation

[0032] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. Furthermore, the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0033] Example 1:

[0034] Please see Figure 1-2As shown, the present invention provides a method for peeling off an organic light-emitting diode substrate, wherein the substrate structure includes a glass substrate 1;

[0035] PET protective layer 2 disposed on the glass substrate 1;

[0036] A first PI protective layer 3 is disposed on the PET protective layer 2;

[0037] TFT driving layer 4 disposed on the first PI protective layer 3;

[0038] RGB light-emitting layer 5 disposed on the TFT driving layer 4;

[0039] A second PI protective layer 6 is disposed on the RGB light-emitting layer 5;

[0040] Linear polarizing layer 7 disposed on the second PI protective layer 6;

[0041] The glass substrate 1 is a transparent substrate, and the material of the glass substrate 1 is a transparent rigid material through which light beams can pass.

[0042] The method for peeling off the substrate includes the following steps:

[0043] S1: The PET protective layer 2 is peeled off by laser;

[0044] S2: The laser is used for stripping by the cooperation of the main laser 8 and the auxiliary laser 9;

[0045] S3: The main laser and the auxiliary laser have different pulse widths, pulse energies, and wavelengths; during peeling, a laser beam is used to irradiate the bottom of the glass substrate of the glass substrate. The focus of the laser acts on different positions of the PET protective layer. The PET protective layer is the first to receive the laser energy. When the PET protective layer is completely vaporized or critically vaporized, peeling is achieved.

[0046] The thickness of the PET protective layer 2 is 10-50 μm.

[0047] In this embodiment, a PET protective layer 2 is coated on the glass substrate 1 using an inkjet printer. After curing, a PI layer is formed. During peeling, a laser beam is used to irradiate the bottom of the glass substrate 1. The focal point of the laser is slightly lower than the PET protective layer 2. The PET protective layer 2 is the first to receive the laser energy. The thickness of the PET protective layer 2 is 10-50 μm. When the PET protective layer 2 is completely vaporized or critically vaporized, the peeling effect can be considered to be achieved.

[0048] Because the substrate may contain foreign objects or be uneven, resulting in laser energy loss, two lasers, a main laser 8 and a secondary laser 9, are used in conjunction to perform laser stripping.

[0049] By using a femtosecond ultrafast laser with a pulse width on the femtosecond level, the beam emitted by the femtosecond ultrafast laser is irradiated from the bottom of the glass substrate onto the PET film layer spin-coated on the substrate for peeling. In contrast to the existing technology where the PI thickness is generally 10 to 100 μm, the spatial scale of the energy concentration of the nanosecond laser is relatively large and difficult to control.

[0050] This invention adds an extra protective layer to the original OLED device structure, which can effectively block the irradiation damage of the functional layer caused by laser energy fluctuations. It can better protect the OLED device, and uses two different femtosecond lasers with pulse widths at the femtosecond level to achieve a smaller heat-affected zone, ensuring the ablation pressure impact effect of the peeling layer with a thickness of only micrometers. It can achieve high-yield laser peeling with large area, no damage, and no residue.

[0051] In a specific embodiment, such as Figure 1 As shown, the laser used in step S1 of the substrate peeling method is a femtosecond ultrafast laser. Irradiation is performed using a femtosecond ultrafast laser with a wavelength range of 100-1200 nm, a pulse width of 500 fs-1 ps, and an energy density of 80-160 mJ / cm². 2 The laser has a repetition frequency of 1-200MHz and a scanning speed of 10-1000mm / s. The ultrashort pulse characteristics of the femtosecond ultrafast laser result in finer particles when it interacts with materials, reducing damage to the heat-affected zone and surrounding materials. The femtosecond ultrafast laser emits a circular focused beam, allowing for better control and selection of the vaporization area during peeling. The femtosecond ultrafast laser is used for cold processing, reducing peeling damage and improving peeling efficiency. The main laser 8 and the auxiliary laser 9 form an adjustable angle of 0-60°.

[0052] In this embodiment, a 30μm PET layer 2 is formed on the glass substrate 1. The angle between the main laser and the secondary laser is 30°. The spot diameter of the main laser 8 is 50μm, and the spot diameter of the secondary laser 9 is 7μm. The main laser is preferably 343nm, 550fs, and 145mJ / cm². 2 100MHz, 800mm / s; preferred secondary laser: 1030mm, 855fs, 120mJ / cm² 2The laser operates at 120MHz and 100mm / s. During the peeling process, the laser is fixed after the z-axis focusing position is adjusted, while the OLED device is moved for laser scanning and peeling. This demonstrates that the parameters used by the two lasers are different, corresponding to the different focusing positions of the main laser 8 and the auxiliary laser 9.

[0053] When the main laser 8 is positioned directly opposite the OLED device to be peeled off, and the auxiliary laser 9 is at an adjustable angle of 0-60° to the main laser 8 during the peeling process, the laser is fixed while the OLED device is moved for laser scanning; alternatively, the OLED device is fixed while the laser is moved for scanning. Furthermore, in addition to moving along the horizontal x and y axes, the workpiece stage containing the OLED device and the laser can also be adjusted along the z axis to ensure the laser focus is on the OLED device. Specifically, the main laser 8 is focused at the junction of the PET and the glass substrate 1 on the side closest to the glass substrate 1, while the auxiliary laser 9 is focused at the center of the PET protective layer 2.

[0054] By modifying the excimer nanosecond pulsed laser to a femtosecond ultrafast laser for stripping, the two laser pulses used have a femtosecond-level width, and the focused beam is a circular focused beam for stripping, which allows for better control and selection of the vaporization region. The high power density characteristics of the femtosecond ultrafast laser can better vaporize refractory materials, and its application in high melting point materials is of great significance.

[0055] In a specific embodiment, such as Figure 1 As shown, in step S2 of the substrate peeling method, the main laser 8 has a spot diameter of 50 μm, and the secondary laser 9 has a spot diameter of less than 10 μm. The main laser performs the peeling action, and the secondary laser performs supplementary peeling on the incompletely peeled areas.

[0056] In this embodiment, the main laser spot diameter is 50 μm, and the secondary laser 9 spot diameter is less than 10 μm. The main laser 8 plays the primary stripping role, with a larger focused spot, while the secondary laser 9 performs supplementary stripping on areas where the stripping is incomplete. On the one hand, this allows for effective processing of any foreign matter or unevenness that may exist on the glass substrate 1. On the other hand, the secondary laser 9 modifies the PET material, making it easier and more effective for the main laser 8 to remove the PET layer.

[0057] In a specific embodiment, such as Figure 1 As shown, the first PI protective layer 3 is fabricated on the PET protective layer 2. By utilizing the different light absorption rates of different materials, the laser can be effectively prevented from entering the OLED device. The release material of the PET protective layer 2 includes, but is not limited to, polybutylene terephthalate, polyethylene naphthalate, polyethersulfone, polyetherimide, polycarbonate, and polyphenylene sulfide.

[0058] In this embodiment, a release layer, namely a PET protective layer 2, is added on top of the original polyimide (PI) layer. However, the release layer material is not limited to polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide (PEI), polycarbonate (PC), and polyphenylene sulfide (PPS). Compared with the existing technology that only has a PI layer, short-wavelength lasers can easily enter the OLED device, affecting its lifespan and performance. By adding a release layer on top of the original polyimide (PI) layer, the different absorption degrees of different materials for lasers can effectively block the light beam from entering the OLED device, thus better protecting the organic light-emitting diode (OLED) device and providing double-layer protection. This effectively blocks the irradiation damage to the functional layer caused by laser energy fluctuations. The release effect is achieved by using two lasers with different pulse widths, pulse energies, and wavelengths, and by utilizing the different effects of different lasers on the materials.

[0059] Example 2:

[0060] like Figure 3 As shown, a 50 μm PBT layer 10 is formed on the glass substrate 1. The angle between the main laser 8 and the secondary laser 9 is 60°. The spot diameter of the main laser 8 is 50 μm, and the spot diameter of the secondary laser 9 is 9 μm. The main laser 8 preferably has a wavelength of 343 nm, a wavelength of 550 fs, and a wavelength of 135 mJ / cm². 2 80MHz, 1000mm / s; secondary laser 9 preferably 1030mm, 855fs, 110mJ / cm 2 The laser speed was 100MHz and 200mm / s. During the peeling process, the OLED device was fixed, and after adjusting the z-axis focusing position, the laser was moved to perform scanning and peeling; the rest was completely consistent with Example 1.

[0061] The basic concepts have been described above. It is clear that the detailed disclosure above is merely illustrative and does not constitute a limitation of this specification. Although not explicitly stated herein, various modifications, improvements, and deviations may be made to this specification by those skilled in the art. Such modifications, improvements, and deviations are suggested in this specification and therefore remain within the spirit and scope of the exemplary embodiments described herein.

[0062] Furthermore, those skilled in the art will understand that various aspects of this specification can be described and illustrated in several patentable ways, including any new and useful combination of processes, machines, products, or substances, or any new and useful improvements thereto. Accordingly, various aspects of this specification can be implemented entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. All of the above hardware or software may be referred to as a “data block,” “module,” “engine,” “unit,” “component,” or “system.” Furthermore, various aspects of this specification may be represented as a computer product located on one or more computer-readable media, including computer-readable program code.

[0063] It should be noted that if there are any inconsistencies or conflicts between the descriptions, definitions, and / or terms used in the supplementary materials to this manual and the contents of this manual, the descriptions, definitions, and / or terms used in this manual shall prevail.

[0064] Finally, it should be understood that the embodiments described in this specification are merely illustrative of the principles of the embodiments described herein. Other variations may also fall within the scope of this specification. Therefore, alternative configurations of the embodiments described herein are intended to be illustrative rather than limiting, and are considered consistent with the teachings of this specification. Accordingly, the embodiments described herein are not limited to those explicitly introduced and described herein.

Claims

1. A method for peeling off an organic light-emitting diode substrate, characterized in that, The substrate structure includes a glass substrate (1). PET protective layer (2) disposed on the glass substrate (1); A first PI protective layer (3) is disposed on the PET protective layer (2); TFT driving layer (4) disposed on the first PI protective layer (3); An RGB light-emitting layer (5) is disposed on the TFT driving layer (4); A second PI protective layer (6) is disposed on the RGB light-emitting layer (5); Linear polarizing layer (7) disposed on the second PI protective layer (6); The method for peeling off the substrate includes the following steps: S1: The PET protective layer (2) is peeled off by laser; S2: The laser is stripped by the cooperation of the main laser (8) and the auxiliary laser (9); S3: The pulse width, pulse energy and wavelength selected by the main laser (8) and the auxiliary laser (9) are different; during peeling, a laser beam is used to irradiate the bottom of the glass substrate (1) and the focus of the laser acts on different positions of the PET protective layer (2). The PET protective layer (2) is the first to receive the laser energy. When the PET protective layer (2) is completely vaporized or critically vaporized, peeling is achieved. The laser used in step S1 is a femtosecond ultrafast laser. Irradiation is performed using a femtosecond ultrafast laser with a wavelength range of 100-1200 nm, a pulse width of 500 fs-1 ps, and an energy density of 80-160 mJ / cm². 2 The repetition frequency is 1-200MHz, and the scanning speed is 10-1000mm / s. By using femtosecond ultrafast laser, the particles generated when the femtosecond ultrafast laser interacts with the PET layer material are made smaller, thereby reducing the corresponding damage to the heat-affected zone and surrounding materials. In step S2, the main laser (8) has a spot diameter of 50 μm, and the secondary laser (9) has a spot diameter of less than 10 μm. The main laser performs the stripping action, and the secondary laser performs supplementary stripping on the incompletely stripped areas.

2. The method for peeling off an organic light-emitting diode substrate according to claim 1, characterized in that: The femtosecond ultrafast laser emits a circular focused beam, which allows for better control and selection of the vaporization region during stripping.

3. The method for peeling off an organic light-emitting diode substrate according to claim 1, characterized in that: The femtosecond ultrafast laser is used for cold processing.

4. The method for peeling off an organic light-emitting diode substrate according to claim 1, characterized in that: In step S2, the main laser (8) and the auxiliary laser (9) are at an adjustable angle of 0-60°.

5. The method for peeling off an organic light-emitting diode substrate according to claim 1, characterized in that: The first PI protective layer (3) is disposed on the PET protective layer (2) to prevent the laser from entering the OLED device by utilizing the different light absorption rates of different materials.

6. The method for peeling off an organic light-emitting diode substrate according to claim 1, characterized in that: The glass substrate (1) is a transparent substrate, and the material of the glass substrate (1) is a transparent rigid material, through which light beams can pass.

7. The method for peeling off an organic light-emitting diode substrate according to claim 1, characterized in that: The thickness of the PET protective layer (2) is 10-50 μm.

8. The method for peeling off an organic light-emitting diode substrate according to claim 1, characterized in that: The peeling material of the PET protective layer (2) includes polybutylene terephthalate, polyethylene naphthalate, polyethersulfone, polyetherimide, polycarbonate and polyphenylene sulfide.

Images