Peeling method for flexible device

Abstract

The present invention discloses a peeling method for a flexible device. The flexible device includes a flexible substrate and a flexible functional layer stacked thereon. One side of the flexible substrate away from the flexible functional layer is disposed on a carrier substrate. The carrier substrate has a separation portion and an adhesion portion located outside the separation portion. The peeling method includes the following steps: scanning the interface between the flexible substrate and the separation portion with a first laser; scanning the interface between the flexible substrate and the adhesion portion with a second laser; wherein the energy density of the first laser is greater than that of the second laser. This peeling method for the flexible device effectively avoids the shedding, warping and damage of the flexible device during the subsequent transfer process, and effectively improves the yield rate of the process of peeling the flexible device.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible display devices, and particularly to a method for peeling a flexible device. Background Art

[0002] Foldable electronic devices can effectively reduce the area occupied by the electronic devices and bring more diverse usage performances. Flexible display devices or foldable display devices are required in foldable electronic devices.

[0003] Traditional flexible display devices generally include the following structure: a flexible substrate, an electrode layer, a flexible thin-film transistor array, a flexible light-emitting functional layer, and a packaging layer, which are sequentially disposed on the flexible substrate. For a flexible display device to achieve overall flexibility, each component therein is required to have a certain and similar bending radius and not be damaged or detached during bending.

[0004] In order to be as compatible as possible with the process for manufacturing rigid display screens, so as to utilize existing production equipment and reduce production costs, a process of attaching and then detaching is usually adopted to manufacture flexible display devices. The attaching production process refers to preparing the entire flexible display device on a glass substrate first, and the detaching production process refers to peeling the prepared entire flexible display device from the glass substrate.

[0005] The method for peeling a flexible display device from a glass substrate can be to scan the interface between the flexible display device and the glass substrate with a laser. The high-energy laser can break the bonding between the flexible substrate material and the substrate material at the interface, thereby eliminating the adhesion force between the flexible substrate material and the substrate material, and separating the flexible substrate from the substrate. In the actual process of manufacturing a flexible display device, considering the problems of laser incidence and deformation of the glass substrate, the glass substrate is usually disposed above and the flexible device is disposed below.

[0006] The flexible display device after laser scanning often still has some areas adhered to the glass substrate, so it usually needs to be transferred to a separation device for complete separation. However, during the transfer to the separation device, the flexible display device is prone to falling off, curling, and being damaged, which greatly affects the yield of manufacturing the flexible display device. Summary of the Invention

[0007] In order to solve as much as possible the problems of peeling off, curling, and damage of the flexible substrate during the transfer to the separation device after laser scanning, and improve the yield of manufacturing the flexible device, the present invention designs a method for peeling a flexible device.

[0008] According to an embodiment of the present invention, a method for peeling a flexible device, the flexible device includes a flexible substrate and a flexible functional layer arranged in a stacked manner, one side of the flexible substrate away from the flexible functional layer is arranged on a carrier substrate, the carrier substrate has a separation part and an adhesion part located outside the separation part, and the peeling method includes the following steps:

[0009] Scanning the interface between the flexible substrate and the separation part with a first laser; and,

[0010] Scanning the interface between the flexible substrate and the adhesion part with a second laser;

[0011] Wherein, the energy density of the first laser is greater than the energy density of the second laser.

[0012] In one embodiment, after scanning the interface between the flexible substrate and the separation part with the first laser, the adhesion force between the separation part and the flexible substrate is eliminated or partially eliminated.

[0013] In one embodiment, after scanning the interface between the flexible substrate and the adhesion part with the second laser, the adhesion force between the flexible substrate and the adhesion part is weakened, and the flexible substrate still adheres to the adhesion part.

[0014] In one embodiment, a functional area and an invalid area located outside the functional area are provided on the flexible substrate, and the flexible functional layer is arranged on the functional area; the adhesion part is opposite to the invalid area.

[0015] In one embodiment, the functional area is located in the middle of the flexible substrate, the invalid area is arranged around the functional area and is located at the edge of the flexible substrate.

[0016] In one embodiment, the material of the flexible substrate is polyimide.

[0017] In one embodiment, the energy density of the first laser is 130 mJ / cm 2 ~160 mJ / cm 2 .

[0018] In one embodiment, the energy density of the second laser is 110 mJ / cm 2 ~120 mJ / cm 2 .

[0019] In one embodiment, the carrier substrate has opposite first and second side edges, and the adhesion part includes:

[0020] A first sub-adhesion part disposed adjacent to the first side edge and a second sub-adhesion part disposed adjacent to the second side edge;

[0021] Wherein, the separation part is located between the first sub-adhesion part and the second sub-adhesion part.

[0022] In one embodiment, the carrier substrate further has another set of opposite third side edges and fourth side edges; wherein, the first sub-adhesion part abuts against the third side edge and the fourth side edge, the second sub-adhesion part abuts against the third side edge and the fourth side edge, and there is a first boundary between the first sub-adhesion part and the separation part, and a second boundary between the second sub-adhesion part and the separation part, and the first boundary and the second boundary are straight lines parallel to each other.

[0023] In one embodiment, both the first laser and the second laser are linear laser beams, and the peeling method specifically is: first move the linear laser beam emitting the second laser to scan the first sub-adhesion part, then move the linear laser beam emitting the first laser to scan the separation part, and then move the linear laser beam emitting the second laser to scan the second sub-adhesion part.

[0024] In one embodiment, a separation part is provided between the first sub-adhesion part and at least one of the third side edge and the fourth side edge, and a separation part is provided between the second sub-adhesion part and at least one of the third side edge and the fourth side edge.

[0025] In one embodiment, during the process of scanning with the first laser, it further includes:

[0026] The step of disposing a mask between the light source of the first laser and the carrier substrate to cover the first sub-adhesion part and the second sub-adhesion part.

[0027] In one embodiment, after the steps of scanning with the first laser and scanning with the second laser, it further includes:

[0028] The step of transferring the flexible device and the carrier substrate as a whole to a separation device, and there is a blade on the separation device;

[0029] The step of using the blade to scratch the interface between the flexible substrate and the adhesion part and dividing the flexible substrate and the adhesion part.

[0030] In one embodiment, the step of transferring the flexible device and the carrier substrate as a whole to a separation device includes: using a supporting device with a flat supporting surface to support the side of the flexible functional layer away from the flexible substrate, and driving the flexible device and the carrier substrate to move to the operating table of the separation device; wherein, a plurality of ventilation holes are provided on the supporting device, one end opening of the ventilation hole is located on the supporting surface, and the other end opening is used to connect with an external air extraction mechanism; when the supporting device supports the flexible functional layer, the flexible functional layer is adsorbed on the supporting surface by pumping air through the ventilation holes.

[0031] During the process of transferring the flexible device and the carrier substrate to the separation device, the flexible display device often falls off, curls, and is damaged. On the one hand, since the adhesion between the flexible substrate and the glass substrate in most areas is removed by the laser, due to the gravity of the flexible substrate itself, local detachment and curling will occur between it and the glass substrate. On the other hand, the gravity of the bonded circuit board (PCB) and chip (COF) will exert excessive pulling force on the flexible substrate, damaging the main body of the flexible device. On the other hand, after the substrate is transferred into the separation device, due to the curling of the flexible substrate, it will also cause difficulties in alignment of the separation device and reduce the yield.

[0032] The above-mentioned peeling method of the flexible device provided by the present invention respectively uses the first laser to scan the interface between the separation part and the flexible substrate and the second laser to scan the interface between the adhesion part and the flexible substrate, so that partial desorption occurs between the flexible substrate and the carrier substrate, effectively reducing the difficulty in the subsequent separation process; the adhesion between part of the flexible substrate and the carrier substrate is weakened but still adheres to the carrier substrate, assisting in shaping the flexible device, avoiding the situation of falling off, warping, and damage of the flexible device during the subsequent transfer process, and improving the yield of the flexible device in the removal preparation process. Description of the Drawings

[0033] Figure 1 Schematic diagram of a flexible display device of an embodiment;

[0034] Figure 2 Top view of a flexible substrate of an embodiment;

[0035] Figure 3 Top view of a carrier substrate of an embodiment;

[0036] Figure 4 Top view of a carrier substrate of another embodiment;

[0037] Figure 5 Schematic diagram of the positions of the mask, the carrier substrate, and the flexible display device during the laser scanning process;

[0038] Figure 6 Schematic diagram of the shape of a flexible display device after laser scanning. Among them, Figure a is the schematic diagram after scanning by the laser scanning method of this embodiment, and Figure b is the schematic diagram after scanning by the traditional laser scanning method;

[0039] Figure 7 Schematic diagram of transporting a flexible display device using a supporting device;

[0040] Figure 8 Schematic diagram of separating a flexible display device and a carrier substrate.

[0041] Among them, the meanings of the respective reference numerals are as follows:

[0042] 110: Flexible substrate; 111: Functional area; 112: Invalid area; 120: Flexible functional layer; 121: Barrier layer; 122: Driving element; 123: Light-emitting device; 124: Encapsulation layer; 125: Polarizer; 20: Carrier substrate; 201: Separation part; 202: Adhesion part; 210: Operating table; 211: Support seat; 220: Mask; 230: Supporting device; 231: Supporting surface; 232: Vent hole; 240: Blade; 30: Carrier substrate; 301: Separation part; 302: Adhesion part. Detailed implementation manners

[0043] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure content of the present invention more thorough and comprehensive.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items. The term "plurality" used herein represents a combination of two or more items. If not explicitly stated or those skilled in the art do not have a common understanding of this, it should be considered that concepts such as proportion or concentration in this application are mass proportion or mass concentration.

[0045] In one embodiment of the present invention, a method for peeling a flexible device is provided. Among them, the flexible device includes a flexible substrate and a flexible functional layer stacked, the side of the flexible substrate away from the flexible functional layer is disposed on a carrier substrate, the carrier substrate has a separation part and an adhesion part located outside the separation part, and the peeling method includes the following steps:

[0046] Use a first laser to scan the interface between the flexible substrate and the separation part; and,

[0047] Use a second laser to scan the interface between the flexible substrate and the adhesion part;

[0048] wherein, the energy density of the first laser is greater than that of the second laser.

[0049] In one specific example, after using the first laser to scan the interface between the flexible substrate and the separation part, the adhesion force between the separation part and the flexible substrate is eliminated or partially eliminated.

[0050] In one specific example, after using the second laser to scan the interface between the flexible substrate and the adhesion part, the adhesion force between the flexible substrate and the adhesion part is weakened, and the flexible substrate still adheres to the adhesion part.

[0051] For the convenience of understanding the specific structure of the flexible device disposed on the carrier substrate in this embodiment, please refer to Figure 1 , a specific schematic diagram of a flexible device.

[0052] The flexible device includes a flexible substrate 110 disposed on a carrier substrate 20 and a flexible functional layer 120 disposed on the flexible substrate 110.

[0053] In one specific example, the carrier substrate 20 is a hard transparent carrier substrate, and its material can specifically be selected from glass.

[0054] In one specific example, the thickness of the carrier substrate 20 is 0.1 mm to 10 mm.

[0055] The carrier substrate 20 can be used as a platform for preparing flexible devices. The hard carrier substrate 20 can help shape the components in the flexible device, making its manufacturing process as a whole similar to that of traditional non-flexible devices, and can effectively reduce the manufacturing cost. The transparent carrier substrate 20 is convenient for observing the overall shape of the flexible device in real time, and, during the subsequent laser scanning process, the transparent carrier substrate 20 basically does not block the transmission of the laser.

[0056] The flexible substrate 110 is used to carry the flexible functional layer 120 thereon. In the subsequent peeling process or other transfer processes, operations can be directly performed on the flexible substrate 110 to avoid direct operations on the flexible functional layer 120. At the same time, the flexible functional layer 120 also adheres to the surface of the carrier substrate with the help of the flexible substrate 110. In one specific example, the material of the flexible substrate 110 is selected from polyimide.

[0057] In one specific example, the thickness of the flexible substrate 110 is 10 μm to 50 μm, and more specifically, the thickness of the flexible substrate 110 can be 20 μm.

[0058] In one specific example, the flexible device is a flexible display device. More specifically, the flexible display device is a display device using an organic light-emitting diode as a light source.

[0059] In one specific example, for the flexible display device, the flexible functional layer 120 may specifically include a barrier layer 121, a driving element 122, a light-emitting device 123, a packaging layer 124, and a polarizer 125 that are sequentially stacked. Among them, the barrier layer 121 is used to block water and oxygen to prevent water and oxygen from permeating; the driving element 122 includes a thin-film transistor (TFT), and the thin-film transistor is used to drive the light-emitting device 123 thereon to emit light. The light-emitting device 123 is an organic light-emitting diode, and the thin-film transistor drives the pixelated light-emitting device 123 to emit light to display a pattern.

[0060] Furthermore, an embodiment of the present invention also provides a method for manufacturing the above flexible device, which may include the following manufacturing process.

[0061] Step S1, prepare a flexible substrate 110 on the surface of the carrier substrate 20.

[0062] In one specific example, the method for preparing the flexible substrate 110 may be, for example: coating a polyimide solution on the surface of the carrier substrate 20, and then performing high-vacuum drying to quickly volatilize and remove most of the solvents in the polyimide. Then, by using the method of heating and drying, the solvents in the polyimide solution are further removed and the polyimide material is crosslinked and cured to finally form a flexible substrate 110 with good thickness uniformity.

[0063] In one specific example, the size of the flexible substrate 110 on the carrier substrate 20 ≥ 31 inches. For example, the flexible substrate 110 is a rectangular film with a size of 730 mm × 460 mm.

[0064] Step S2, prepare a flexible functional layer 120 on the side of the flexible substrate 110 away from the carrier substrate 20.

[0065] The flexible functional layer 120 is the functional main body of the flexible device and is used to exert the functions of the flexible device. In this specific example, the flexible device is a flexible display device.

[0066] Please refer to simultaneously Figure 2, a top view of the flexible substrate 110. In one specific example, the flexible substrate 110 has a functional area 111 and a non-functional area 112 disposed outside the functional area 111, and the flexible functional layer 120 is disposed on the functional area 111. Specifically, the top view of the flexible substrate 110 is rectangular, the functional area 111 is located at the center of the flexible substrate 110 and is also rectangular, and the non-functional area 112 surrounds the functional area 111 and is located at the periphery of the flexible substrate 110, forming a rectangular ring.

[0067] Further, for example, the area of the flexible substrate 110 protrudes 10 mm to 50 mm beyond the edge of the flexible functional layer 120. Specifically, the size of the flexible substrate 110 is 730 mm × 460 mm, the size of the flexible functional layer 120 disposed on the flexible substrate 110 is 690 mm × 400 mm, the flexible functional layer 120 is disposed in the central area of the flexible substrate 110, the distance between its long side and the long side of the flexible substrate 110 is 30 mm, and the distance between its short side and the short side of the flexible substrate 110 is 20 mm.

[0068] In one specific example. The specific preparation process of the flexible functional layer 120 may include: sequentially preparing a barrier layer 121, a driving element 122, a pixelated light-emitting diode 123, a packaging layer 124, and a polarizer 125. The barrier layer 121 may adopt an organic / inorganic alternating structure, such as parylene / silicon nitride / parylene / silicon nitride stacked layers, or may adopt an inorganic / inorganic alternating structure, such as silicon nitride / silicon dioxide / silicon nitride stacked layers. Then, the driving element 122 is fabricated on the barrier layer 121. Specifically, the driving element 122 includes a thin-film transistor array for driving the light-emitting device. According to the different TFT process temperatures, materials of the flexible substrate 110 with different temperature resistance properties can be correspondingly selected. Then, the light-emitting diode 123 is prepared, and the thin-film packaging is performed to prepare the packaging layer 124, and then the polarizer 125 is set. The preparation method of the light-emitting diode 123 can be selected from a printing process or a vapor deposition process.

[0069] In one specific example, the steps of preparing the flexible functional layer 120 further include the step of bonding the bonding area leads to the external COF to complete the bonding. This process can be completed on the carrier substrate 20, and its manufacturing process is not much different from the traditional technology and is relatively easy. If this process is carried out after the flexible functional layer 120 is peeled off from the carrier substrate 20, in the absence of the auxiliary shaping of the carrier substrate 20, the flexible functional layer 120 is extremely prone to bending and other deformations, and it is difficult to accurately align the bonding process, resulting in poor bonding.

[0070] Thus, the preparation of the flexible device on the carrier substrate 20 can be completed. However, the carrier substrate 20 is only used as a temporary preparation platform and cannot be part of the flexible device. Therefore, the carrier substrate 20 needs to be separated from the flexible device in the subsequent process. Since the flexible functional layer 120 itself is very fragile, it is required that the separation process has as little impact on the flexible functional layer 120 as possible. For example, significant bending or curling should not occur on the flexible functional layer 120, and even more so, the flexible functional layer 120 should not be damaged.

[0071] By focusing the laser on the interface between the flexible substrate 110 and the carrier substrate 20 and scanning the entire area where the flexible substrate 110 is located, the adhesion force between the flexible substrate 110 and the carrier substrate 20 can be eliminated without affecting the flexible functional layer 120, so it is commonly used in the process of peeling the flexible device from the carrier substrate 20.

[0072] Generally, during the laser peeling of the flexible device, the carrier substrate 20 is usually placed upwards (the "up" here refers to the orientation relative to the ground), while the flexible functional layer 120 is usually placed downwards.

[0073] The reasons for placing the carrier substrate 20 upwards and the flexible functional layer 120 downwards are as follows. The laser needs to pass through the carrier substrate 20 to reach the interface between the carrier substrate 20 and the flexible substrate 110. If the carrier substrate 20 is placed downwards, the carrier substrate 20 needs to be supported by other support members. The support frame will either block the laser or cause the carrier substrate 20 to bend slightly under the action of gravity, making it difficult for the laser to be accurately focused and aligned. Therefore, during the laser scanning process, usually the laser irradiates from top to bottom, with the carrier substrate 20 facing upwards and the flexible device facing downwards.

[0074] The above embodiments provide a method for preparing a flexible device disposed on a carrier substrate 20. It can be understood that in other embodiments, the flexible device disposed on the carrier substrate can also be obtained through other means. The following embodiments of the present invention can be used to peel the flexible device from the carrier substrate to which it is attached.

[0075] The peeling method in this embodiment includes the laser scanning in step S3 and step S4 as follows.

[0076] In one specific example, before scanning the carrier substrate 20 with the laser, the peeling method further includes the step of cleaning the side of the carrier substrate 20 away from the flexible substrate 110 to avoid impurities on the carrier substrate 20 affecting the laser irradiation.

[0077] To more intuitively understand the separation part and the adhesion part located outside the separation part, please refer to Figure 3, in a specific example of this embodiment, the carrier substrate 20 has a separation portion 201 and an adhesion portion 202, and the adhesion portion 202 is located outside the separation portion 201.

[0078] Step S3: Use a first laser to scan the interface between the separation portion 201 and the flexible substrate 110 through the carrier substrate 20 to eliminate or partially eliminate the adhesion force between the separation portion 201 and the flexible substrate 110.

[0079] Specifically, the first laser is focused on the interface between the flexible substrate 110 and the carrier substrate 20 so that the laser energy at the interface between the flexible substrate 110 and the carrier substrate 20 is as high as possible. The first laser acts between the interfaces of the flexible substrate 110 and the carrier substrate 20, and the high-energy laser beam can break the bonds formed between the flexible substrate 110 and the carrier substrate 20, thereby eliminating the adhesion force between the flexible substrate 110 and the carrier substrate 20.

[0080] The first laser is focused on the entire interface between the separation portion 201 and the flexible substrate 110 for scanning. It can be understood that after the first laser scans the interface between the separation portion 201 and the flexible substrate 110, ideally, the adhesion force between the entire separation portion 201 and the flexible substrate 110 should be eliminated. However, due to possible errors in the actual operation process, there may still be a very small number of local separation portions 201 that still have an adhesion force with the flexible substrate 110. Therefore, the adhesion force between the entire separation portion 201 and the flexible substrate 110 may also be partially eliminated.

[0081] In one specific example, the adhesion portion 202 on the carrier substrate 20 is disposed opposite to the invalid area 112 on the flexible substrate 110. Here, "opposite" means that when the flexible substrate 110 is closely attached to the carrier substrate 20, the orthographic projection of the adhesion portion 202 on the flexible substrate 110 along the direction perpendicular to the interface between the two falls within the invalid area 112.

[0082] In one specific example, the carrier substrate 20 has opposite first and second sides, and there are multiple adhesion portions 202. The multiple adhesion portions 202 include a first sub-adhesion portion disposed close to the first side and a second sub-adhesion portion disposed close to the second side. The separation portion 201 is located between the first sub-adhesion portion and the second sub-adhesion portion.

[0083] Furthermore, the number and shape of the first sub-adhesion portion are the same as those of the second sub-adhesion portion. Further, one side of one of the first side and the second side is used for external chip bonding.

[0084] For example, the carrier substrate 20 is rectangular, and the adhesion part 202 includes a first sub - adhesion part and a second sub - adhesion part; optionally, the shapes of the first sub - adhesion part and the second sub - adhesion part are rectangles with the same size and shape. The following elaborates two feasible setting methods of the adhesion part 202 through two specific examples.

[0085] In this specific example, the carrier substrate 20 also has another set of opposite third side and fourth side. A separation part 201 is provided between the first sub - adhesion part and at least one of the third side and the fourth side, and a separation part 201 is provided between the second sub - adhesion part and at least one of the third side and the fourth side.

[0086] Please refer to Figure 3 , the carrier substrate 20 is rectangular, the first side and the second side are one set of opposite sides of the rectangle, and the third side and the fourth side are the other set of opposite sides of the rectangle. According to the orientation shown in the figure, specifically, the adhesion part 202 includes a first sub - adhesion part arranged close to the left side of the carrier substrate 20 and a second sub - adhesion part arranged close to the right side of the carrier substrate 20. There are intervals between the first sub - adhesion part and the upper side and the lower side, that is, it does not abut against the upper side and the lower side, and there are also intervals between the second sub - adhesion part and the upper side and the lower side. In this way, the carrier substrate 20 has a first sub - adhesion part and a second sub - adhesion part that are arranged adjacent to the left and right sides respectively and abut against the upper and lower sides. Further, the shapes of the first sub - adhesion part and the second sub - adhesion part are rectangles, which is convenient for the scanning of the linear laser beam.

[0087] In one of the specific examples, the two adhesion parts 202 are symmetric about the mid - line of the long side of the rectangle; further, the two adhesion parts 202 are also symmetric about the mid - line of the short side of the rectangle.

[0088] In another specific example, the carrier substrate also has a set of opposite third side and fourth side. The first sub - adhesion part abuts against the third side and the fourth side, the second sub - adhesion part abuts against the third side and the fourth side, and there is a first boundary between the first sub - adhesion part and the separation part, and a second boundary between the second sub - adhesion part and the separation part. The first boundary and the second boundary are straight - line boundaries parallel to each other.

[0089] Specifically, please refer to Figure 4, another rectangular carrier substrate 30, where the first side and the second side are a set of opposite sides of the rectangle, and the third side and the fourth side are the other set of opposite sides of the rectangle. It has a separation part 301 and an adhesion part 302. In this specific example, the adhesion part 302 includes a first sub-adhesion part arranged close to the left side of the carrier substrate 30 and a second sub-adhesion part arranged close to the left side. Each sub-adhesion part abuts against the upper side and the lower side. In this way, the carrier substrate 30 has an adhesion part 302 arranged adjacent to the two short sides and abutting against the two long sides. Further, the boundary between the first sub-adhesion part and the separation part 301 is a straight line, and the boundary between the second sub-adhesion part and the separation part 302 is a straight line parallel to the above straight line. Further, each adhesion part is rectangular, and the separation part 301 is also rectangular.

[0090] In one embodiment, the area of the carrier substrate 20 other than the adhesion part 202 is the separation part 201.

[0091] In one specific example, the first laser uses a linear laser beam. Specifically, the first laser uses a laser emitter capable of generating a linear laser beam. The linear laser beam can scan an area of a line, and by moving the linear laser beam, a planar area can be scanned. The width of the linear laser beam is set according to the size of the flexible substrate 20. For example, for the flexible substrate 20 with a size of 730 mm × 460 mm, the width of the first laser can be set to 730 mm. Moving the linear laser beam along one long side of the flexible substrate 20 to the opposite long side can scan the entire flexible substrate 20.

[0092] For Figure 4 the separation part 301 and the adhesion part 302 of the carrier substrate 30 shown, since each sub-adhesion part abuts against the two long sides, when scanning with the first laser, the width of the linear laser beam scan can be directly restricted. Scanning from one side of the separation part 201 to the other side can complete the scan. Similarly, when scanning with the second laser subsequently, scanning from one side of the first sub-separation part to the other side and from one side of the second self-separation part to the other side can complete the scan of the separation part.

[0093] It can be understood that for Figure 4 the carrier substrate 30 shown, both the first laser and the second laser are linear laser beams. The peeling method is specifically: first move the linear laser beam of the second laser to scan the first sub-adhesion part, then move the linear laser beam of the first laser to scan the separation part 301, and then move the linear laser beam of the second laser to scan the second sub-adhesion part. Since the difference between the first laser and the second laser can only be in energy, by scanning from one side to the other side and adjusting the energy to switch between the first laser and the second laser during the scan, the overall time spent on laser scanning can be greatly saved.

[0094] This embodiment continues to use Figure 3 the separation part 201 and the adhesion part 202 of the carrier substrate 20 shown as examples to elaborate on the peeling method. Since there is a gap between the adhesion part 202 and the two long sides, and a linear laser beam can usually only irradiate a rectangular area, the linear laser beam cannot scan the entire separation part 201 in one pass and needs to divide the separation part 201 into multiple rectangular areas for scanning, but such scanning efficiency is very low.

[0095] As Figure 5 , in one specific example, the first laser scanning is performed on the operation table 210. There is a support seat 211 on the operation table 210. The support seat 211 abuts against the flexible functional layer 120 and is used to support the flexible device and the carrier substrate 20 as a whole. There is a storage hole corresponding to the support seat 211 on the operation table 210, and the support seat 211 can be retracted into the storage hole or extended from the storage hole. When using the first laser scanning, in order to ensure that the first laser scans to the separation part, a mask 220 can be used to block the part outside the separation part 201, so that the first laser acts on the separation part 201 during the scanning process.

[0096] By using the mask 220 to block the part outside the separation part 201, the first laser only acts on the area of the separation part 201. This scanning method can ignore the shape of the separation part 201 or the adhesion part 202 and only needs one scan to complete. In one specific example, the energy density of the first laser is 130 mJ / cm 2 ~160 mJ / cm 2 . For example, the energy density of the first laser is 130 mJ / cm 2 , 140 mJ / cm 2 , 150 mJ / cm 2 , 160 mJ / cm 2 , or the range between each energy density.

[0097] In one specific example, the frequency of the first laser is 50 Hz to 600 Hz. For example, the frequency of the first laser is 50 Hz, 100 Hz, 300 Hz, 500 Hz, 600 Hz, or the range between each frequency.

[0098] In one specific example, the overlap rate of the linear laser beam is 50% to 85%.

[0099] In one specific example, before the first laser scanning, the support base 211 on the operation table 210 can be controlled to lift the flexible device and the carrier substrate 20 as a whole, so that the interface between the flexible substrate 110 and the carrier substrate 20 coincides with the focal plane of the first laser. The lifted distance is related to the distance from the origin of the operation table 210 to the focal plane of the first laser. For example, in this embodiment, the distance from the origin of the operation table 210 to the focal plane of the first laser is 10 mm, then the flexible device and the carrier substrate 20 are lifted as a whole by 10.0 mm to 10.6 mm. More preferably, the flexible device and the carrier substrate 20 are lifted as a whole by 10.0 mm.

[0100] By setting the scanning conditions as above, the adhesion force between the flexible substrate 110 and the carrier substrate 20 can be eliminated or partially eliminated. However, it can be understood that due to inevitable errors in the preparation process, such as the error of the laser and the influence of impurity particles on the carrier substrate 20, there are still a small number of sites adhered at the interface between the flexible substrate 110 and the carrier substrate 20, which is within the allowable error range.

[0101] Step S4, use the second laser to scan the interface between the flexible substrate 110 and the adhesion part 202 to weaken the adhesion force between the flexible substrate 110 and the adhesion part 202, and keep the flexible substrate 110 still adhered to the carrier substrate 20 of the adhesion part 202.

[0102] After the second laser scanning, the symmetrically arranged adhesion parts 202 can ensure that the flexible substrate 110 still bonded to the carrier substrate 20 can evenly share the gravity of the flexible device as much as possible.

[0103] In one specific example, the second laser uses a linear laser beam. Further, during the second laser scanning, only the adhesion part 202 is scanned. To ensure that the second laser scans to the adhesion part 202 and does not affect the already scanned separation part 201, the following method can be used for setting. For example, a corresponding mask can be used to shield the part of the laser irradiating the separation part 201, so that the linear laser beam only acts on the adhesion part 202. Or, there is a laser emitter with a built-in laser beam intercepting module. The laser beam intercepting module can intercept part of the linear laser beam and only retain the part of the linear laser beam irradiating the adhesion part 202, and the boundary of the adhesion part 202 is located by the CCD to complete the second laser scanning.

[0104] In one specific example, the energy density of the second laser is lower than that of the first laser.

[0105] In one specific example, the energy density of the second laser is 110 mJ / cm 2 ~120 mJ / cm 2For example, the energy density of the second laser is 110 mJ / cm 2 、113 mJ / cm 2 、116 mJ / cm 2 、120 mJ / cm 2 , or the range between each energy density.

[0106] In one specific example, the frequency of the second laser is 50 Hz to 600 Hz. For example, the frequency of the second laser is 50 Hz, 100 Hz, 300 Hz, 500 Hz, 600 Hz, or the range between each frequency. More specifically, the frequency of the second laser is the same as that of the first laser.

[0107] In one specific example, the overlap rate of the linear laser beam is 50% to 85%. More specifically, the overlap rate of the second laser is the same as that of the first laser.

[0108] In one specific example, during the laser scanning process, the distance between the carrier substrate 20 and the second laser source is kept the same as the distance from the first laser source.

[0109] As Figure 6 a, by scanning the separation part 201 with the first laser having a higher energy, the adhesion force between the flexible substrate 110 and the carrier substrate 20 of the separation part 201 can be effectively removed. Partial separation occurs between the flexible substrate 110 and the separation part 201. However, due to the existence of the adhesion part 202, the flexible substrate 110 does not deform or warp; then, by scanning the adhesion part 202 with the second laser having a lower energy, the adhesion force between the flexible substrate 110 and the carrier substrate 20 of the adhesion part 202 is weakened, but the flexible substrate 110 still adheres to the carrier substrate 20 of the adhesion part 202. In this way, the overall flexible device after laser peeling can still adhere to the carrier substrate 20, ensuring that the flexible device will not deform, warp, or be overly stretched due to the gravity of the flexible device during the subsequent transfer process. At the same time, the adhesion force between the flexible substrate 110 and the carrier substrate 20 is weakened as much as possible, facilitating subsequent further transfer and separation. As Figure 6 b, in another example where the carrier substrate 20 and the flexible substrate 110 are directly scanned over the entire surface by the laser, since the overall adhesion force between the flexible substrate 110 and the carrier substrate 20 is directly eliminated, the flexible substrate 110 undergoes obvious deformation and warping under its own gravity, and the flexible device is also damaged.

[0110] Step S5, separate the flexible substrate 110 from the carrier substrate 20 of the adhesion part 201.

[0111] Please refer to Figure 7, in one specific example, before separating the flexible substrate 110 from the carrier substrate 20 of the adhesion part 201, it further includes the step of transferring the carrier substrate 20 provided with the flexible device to the separation device. The method of this transfer is as follows: Use a supporting device 230 with a flat supporting surface 231 to support the surface of the flexible functional layer 120 away from the flexible substrate 110, and drive the flexible device and the carrier substrate 20 to move to the operating table of the separation device.

[0112] In one specific example, openings of a plurality of ventilation holes 232 are provided on the supporting surface 231 of the supporting device 230, and the other end openings of the ventilation holes 232 are used to connect with an external air extraction mechanism. When the supporting device supports the flexible functional layer 120, it further includes the step of extracting air from the ventilation holes 232 so that the flexible functional layer 120 is adsorbed on the supporting surface 231 of the supporting device 230. Such a setting can fix the flexible functional layer 120 and prevent the flexible functional layer 120 from undergoing deformation defects such as offset during transfer, which affects subsequent accurate operations.

[0113] Please refer to Figure 5 , in one specific example, the method of separating the flexible substrate 110 from the carrier substrate 20 of the adhesion part 202 is as follows: Use a blade 240 to cut the carrier substrate 20 between the flexible substrate 110 and the adhesion part 202. More specifically, insert the blade 240 between the flexible substrate 110 and the carrier substrate 20, determine the depth of insertion of the blade 240 according to the size of the adhesion part 202, and make the blade slide across the adhesion part 202 to separate the flexible substrate 110 from the carrier substrate 20 of the adhesion part 202. For example, for the case where the adhesion part 202 is rectangular, the depth of insertion of the blade 240 should be greater than or equal to the distance between the opposite sides of the rectangle.

[0114] In this way, the entire flexible device is separated from the carrier substrate 20, and the flexible device can easily complete the removal process and enter the subsequent manufacturing process.

[0115] It should be understood that simply using the blade 240 cannot directly separate the carrier substrate 20 from the flexible device. This is because when the blade 240 penetrates the interface between the carrier substrate 20 and the flexible substrate 110, it will adhere to the material of the flexible substrate 110 and cause the flexible substrate 110 to slip, which will drive the flexible functional layer 120 to undergo a large deformation at the same time, ultimately damaging the flexible device. To solve this problem of poor cutting, in this embodiment, first use the second laser to irradiate the adhesion part 202 to weaken the adhesion force between the flexible substrate 110 and the adhesion part 202, which substantially causes partial deterioration of the material of the flexible substrate 110 at the interface and reduces the adhesion force on its surface. Therefore, after the second laser irradiation, during the subsequent cutting process, the blade 240 will not drive the flexible substrate 110 to slip, ensuring the integrity of the entire flexible device.

[0116] More specifically, the blade 240 can be inserted from the third side or the fourth side of the carrier substrate 20, that is, from the two longer sides in the figure.

[0117] More specifically, as Figure 3 The separation part 201 and the adhesion part 202 are arranged. The blade 240 can be inserted from the side where the separation part 201 exists between the third side and the fourth side and the first sub - adhesion part, that is, the blade 240 can be inserted from the side where the separation part 201 exists between the third side and the fourth side and the second sub - adhesion part. At this time, since there is a separation part 201 between the adhesion part 202 and a part of the edge of the carrier substrate 20, the separation part 201 here is separated during the first laser scanning process, which can greatly reduce the difficulty of the blade 240 extending between the flexible substrate 110 and the carrier substrate 20. While improving the efficiency of the blade 240 in cutting the flexible substrate 110 and the carrier substrate 20, it can avoid damage to the flexible device due to excessive adhesion force of the blade 240.

[0118] The technical features of the above - mentioned embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above - mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0119] The above - mentioned embodiments only represent a preferred implementation manner of the present invention, and the description is relatively specific and detailed. However, it should not be understood as a limitation to the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.

Claims

1. A method for peeling a flexible device, characterized in that, the flexible device includes a flexible substrate and a flexible functional layer arranged in a stacked manner, one side of the flexible substrate away from the flexible functional layer is arranged on a carrier substrate, the carrier substrate has a separation part and an adhesion part located outside the separation part, the carrier substrate has opposite first and second side edges, and the adhesion part includes: a first sub-adhesion part closely arranged along the first side edge and a second sub-adhesion part closely arranged along the second side edge; wherein, the separation part is located between the first sub-adhesion part and the second sub-adhesion part; the peeling method includes the following steps: scanning the interface between the flexible substrate and the separation part with a first laser; and, scanning the interface between the flexible substrate and the adhesion part with a second laser; wherein, the energy density of the first laser is greater than that of the second laser, both the first laser and the second laser are linear laser beams, and the peeling method is specifically: first move the linear laser beam of the second laser to scan the first sub-adhesion part, then move the linear laser beam of the first laser to scan the separation part, and then move the linear laser beam of the second laser to scan the second sub-adhesion part.

2. The method for peeling a flexible device according to claim 1, characterized in that, after scanning the interface between the flexible substrate and the separation part with the first laser, the adhesion force between the separation part and the flexible substrate is eliminated or partially eliminated; and / or after scanning the interface between the flexible substrate and the adhesion part with the second laser, the adhesion force between the flexible substrate and the adhesion part is weakened, and the flexible substrate still adheres to the adhesion part.

3. The method for peeling a flexible device according to claim 1, characterized in that, a functional area and an invalid area located outside the functional area are arranged on the flexible substrate, and the flexible functional layer is arranged on the functional area; the adhesion part is opposite to the invalid area.

4. The method for peeling a flexible device according to claim 3, characterized in that, the functional area is located in the middle of the flexible substrate, the invalid area is arranged around the functional area and is located at the edge of the flexible substrate.

5. The method for peeling a flexible device according to claim 1, characterized in that, the material of the flexible substrate is polyimide.

6. The method for peeling a flexible device according to claim 1, characterized in that, The energy density of the first laser is 130 mJ / cm 2 ~160 mJ / cm 2 ; and / or The energy density of the second laser is 110 mJ / cm 2 ~120 mJ / cm 2 .

7. The method for peeling a flexible device according to claim 1, characterized in that, the carrier substrate also has another set of opposite third and fourth side edges, the first sub-adhesion part abuts against the third and fourth side edges, the second sub-adhesion part abuts against the third and fourth side edges, and there is a first boundary between the first sub-adhesion part and the separation part, and a second boundary between the second sub-adhesion part and the separation part, and the first boundary and the second boundary are straight boundaries parallel to each other.

8. The method for peeling a flexible device according to claim 1, characterized in that, The carrier substrate further has another set of opposite third and fourth side edges, and the separating portion is disposed between the first sub-adhesion portion and at least one of the third and fourth side edges, and the separating portion is disposed between the second sub-adhesion portion and at least one of the third and fourth side edges.

9. The peeling method of the flexible device according to claim 8, characterized in that during the first laser scanning, it further includes: a step of disposing a mask between the light source of the first laser and the carrier substrate to cover the first sub-adhesion portion and the second sub-adhesion portion.

10. The peeling method of the flexible device according to any one of claims 1 to 6, characterized in that after the steps of using the first laser scanning and using the second laser scanning, it further includes: a step of transferring the flexible device and the carrier substrate as a whole to a separating device having a blade on the separating device; a step of using the blade to scrape across the interface between the flexible substrate and the adhesion portion to separate the flexible substrate from the adhesion portion.

11. The peeling method of the flexible device according to claim 10, characterized in that the step of transferring the flexible device and the carrier substrate as a whole to the separating device includes: using a supporting device with a flat supporting surface to support the side of the flexible functional layer away from the flexible substrate, and driving the flexible device and the carrier substrate to move to the operating table of the separating device; wherein, a plurality of ventilation holes are provided on the supporting device, one end opening of the ventilation hole is located on the supporting surface, and the other end opening is used for connecting with an external air extraction mechanism; when the supporting device supports the flexible functional layer, the flexible functional layer is adsorbed on the supporting surface by evacuating the ventilation holes.

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