Processing method of flexible electronic device and flexible electronic device

Abstract

The invention provides a processing method of a flexible electronic device and the flexible electronic device, belongs to the technical field of semiconductor devices, and aims to enable the flexible electronic device to be applicable to scenes with high thickness requirements. The method comprises the following steps: providing a substrate, and preparing a temporary bonding layer on the surface of one side of the substrate; fixing a plurality of chips on the surface of one side, deviating from the substrate, of the temporary bonding layer; wherein a gap is formed between every two adjacent chips; filling a gap between every two adjacent chips in the plurality of chips with a liquid flexible high-molecular polymer so as to realize flexible connection among the plurality of chips; and carrying out de-bonding processing on the temporary bonding layer so as to peel off the substrate and obtain the flexible electronic device.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and in particular to a processing method of a flexible electronic device and a flexible electronic device. Background Art

[0002] Flexible electronic technology is currently a cutting-edge research hotspot in the field of electronic technology. Currently, the flexibility of various flexible electronic products mostly relies on the flexibility of display materials, while integrated circuit chips and sensors are still rigid as a whole.

[0003] At present, the preparation process of flexible electronic systems includes two technical routes: one is to use organic materials such as organic polymers and organic semiconductors with intrinsic flexibility to prepare flexible electronic devices through printing and surface modification technology; the other is to transfer ultra-thin five-level materials to flexible or elastic substrates to achieve the flexibility of inorganic semiconductor chips. However, the mobility of existing organic semiconductors is not high, and inorganic semiconductors are difficult to meet the flexibility requirements of chips with thickness requirements. Summary of the invention

[0004] In view of this, the present invention aims to provide a processing method of a flexible electronic device and a flexible electronic device to partially or completely solve the above problems.

[0005] A first aspect of the present invention provides a method for processing a flexible electronic device, comprising:

[0006] providing a substrate;

[0007] Preparing a temporary bonding layer on one side surface of the substrate;

[0008] Fixing a plurality of chips on a surface of the temporary bonding layer facing away from the substrate, wherein there is a gap between two adjacent chips;

[0009] Filling the gap between every two adjacent chips in the plurality of chips with a liquid flexible high molecular polymer to achieve flexible connection between the plurality of chips;

[0010] The temporary bonding layer is subjected to a debonding process to peel off the substrate to obtain the flexible electronic device.

[0011] Exemplarily, the step of filling the gap between every two adjacent chips in the plurality of chips with a liquid flexible polymer comprises:

[0012] Using a preset process to uniformly fill the liquid flexible polymer in the plurality of gaps, and flattening the surface of the liquid flexible polymer;

[0013] A metal layer is formed on a side of the plurality of chips facing away from the substrate, and the metal layer is etched to obtain a plurality of first metal patterns; wherein each of the first metal patterns is configured to electrically connect two adjacent chips.

[0014] Exemplarily, the orthographic projection of each of the first metal patterns on the surface of the substrate overlaps with the orthographic projections of two adjacent chips on the surface of the substrate, and covers the orthographic projections of the liquid flexible polymer in the gap on the surface of the substrate.

[0015] Exemplarily, a connection area is formed on the surface of the liquid flexible high molecular polymer, and the orthographic projection of the connection area on the surface of the substrate overlaps with the orthographic projection of the gap on the surface of the substrate;

[0016] The method further comprises:

[0017] The metal layer is etched to obtain a second metal pattern, wherein the orthographic projection of the second metal pattern on the surface of the substrate at least partially overlaps with the orthographic projection of the chip adjacent to the connection area on the surface of the substrate, and the second metal pattern extends into the connection area.

[0018] Exemplarily, the preset process includes any one of a dry film lamination process, a chemical vapor deposition process, and a spin coating process.

[0019] Exemplarily, the step of fixing the plurality of chips on a surface of the temporary bonding layer facing away from the substrate includes:

[0020] A chip mounter or a flip-chip bonding machine is used to connect a surface of the chip away from the chip pins with the temporary bonding layer, so as to temporarily bond the chip to the substrate.

[0021] Exemplarily, the thickness of the portion of the liquid flexible polymer filling the gap in a target direction is greater than or equal to the thickness of the plurality of chips in the target direction, and the target direction is the direction in which the substrate points to the chip.

[0022] Exemplarily, the liquid flexible high molecular polymer includes at least one of polyimide and polyparaxylene.

[0023] Exemplarily, the debonding process includes any one of a thermal decomposition process, a wet dissolution process, and a photodecomposition process.

[0024] A second aspect of the present invention provides a flexible electronic device, wherein the flexible electronic device is manufactured by the method for manufacturing the flexible electronic device as described in the first aspect.

[0025] The processing method of the flexible electronic device provided by the present invention comprises: providing a substrate; preparing a temporary bonding layer on one side surface of the substrate; fixing a plurality of chips on a side surface of the temporary bonding layer away from the substrate; wherein a gap is provided between two adjacent chips; filling the gap between the plurality of chips with a liquid flexible high molecular polymer to achieve a flexible connection between the plurality of chips; performing a debonding treatment on the temporary bonding layer to peel off the substrate to obtain the flexible electronic device;

[0026] Therefore, the present invention uses a temporary bonding layer to bond multiple chips to a substrate, and then uses a liquid flexible polymer to flexibly connect the multiple chips, and then debonds the temporary bonding layer, so that the multiple flexibly connected chips can be peeled off the substrate to obtain a flexible electronic device. In this way, the processed flexible electronic device can be flexible without a substrate, and the thickness of the flexible electronic device is thinned, making it suitable for flexible electronic device scenarios with high thickness requirements. Moreover, since the processing method is simple and easy, large-scale manufacturing can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0028] Figure 1 A flowchart showing the steps of a method for processing a flexible electronic device provided by an embodiment of the present invention is shown;

[0029] Figure 2a A schematic diagram of an intermediate structure after providing a substrate is shown;

[0030] Figure 2b A schematic diagram of the intermediate structure after preparing the temporary bonding layer is shown;

[0031] Figure 2c A schematic diagram of the intermediate structure after the chip is fixed is shown;

[0032] Figure 2d A schematic diagram of the intermediate structure after filling with liquid flexible polymer is shown;

[0033] Figure 2e A schematic diagram of the intermediate structure after multiple chips are electrically connected is shown;

[0034] Figure 2f A schematic structural diagram of a flexible electronic device obtained by processing the flexible electronic device processing flow according to an embodiment of the present invention is shown;

[0035] Description of reference numerals:

[0036] 10. substrate; 20. temporary bonding layer; 30. chip; 40. liquid flexible high polymer; 50. first metal pattern; 60. second metal pattern. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned purpose, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The following is a detailed description of the embodiments of the present invention. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments. If the specific experimental steps or conditions are not indicated in the embodiments, the operation or conditions of the conventional experimental steps described in the prior art in this field can be carried out. The reagents used and other instruments that do not indicate the manufacturer are all conventional reagent products that can be obtained commercially.

[0038] The advent of the information age has put forward new intelligent requirements for information terminals, such as wearable, implantable, and human-computer interaction, which has brought new challenges to traditional rigid electronic devices. It is urgent to explore the implementation of flexible electronic information systems. Flexible electronic technology integrates multidisciplinary knowledge such as microelectronics, materials science, mechanics, and bionics. The prepared flexible electronic system can work effectively in various deformation modes such as bending, folding, stretching, and twisting. It has broad demand and application prospects in wearable / implantable devices, aerospace, health care, smart Internet, and all fields of the future smart society. The flexible electronic technology that has emerged has become a cutting-edge research hotspot in the field of electronic technology worldwide, and is considered to be an important direction for the future development of electronic information systems.

[0039] At present, there are mainly two processing routes for flexible electronic systems. One is to use intrinsically flexible organic polymers, organic semiconductors and other organic materials to prepare flexible electronic devices through printing and surface modification technology. The other is to transfer ultra-thin inorganic materials to flexible or elastic substrates to achieve the flexibility of inorganic semiconductors.

[0040] However, the carrier mobility in organic semiconductor materials is low, much lower than that of inorganic semiconductor materials such as silicon; inorganic semiconductor materials achieve flexibility through substrates, which makes it difficult to achieve the flexibility of electronic devices that have thickness requirements.

[0041] In view of this, the present invention provides a processing method for a flexible electronic device and a flexible electronic device. The chip is bonded to a substrate through a temporary bonding layer. After the flexible connection of multiple chips is completed on the substrate, the substrate is peeled off by debonding to obtain a flexible electronic device. Thus, the thickness of the flexible electronic device is thinned by peeling off the substrate to improve its performance. In addition, since the processing method is simple and easy, it is conducive to large-scale manufacturing.

[0042] Specifically, refer to Figure 1 , Figure 1 A flowchart of the steps of a method for processing a flexible electronic device provided by an embodiment of the present invention is shown. The method specifically includes:

[0043] S1, providing a substrate 10.

[0044] Among them, Figure 2a As shown, Figure 2a is a schematic diagram of the structure of the substrate 10. The substrate 10 is a rigid material, which may be a silicon wafer or a glass wafer.

[0045] S2, preparing a temporary bonding layer 20 on one side surface of the substrate 10.

[0046] Specifically, after a temporary bonding layer 20 is prepared on one side surface of the substrate 10, a Figure 2b In the structure shown, the temporary bonding layer 20 covers the entire surface of the substrate 10, so that the chip 30 can be conveniently fixed at any position on the surface of the substrate 10, wherein the thickness of the temporary bonding layer 20 is sufficient to facilitate debonding.

[0047] The temporary bonding layer 20 can be formed by coating a temporary bonding material on the surface of the substrate 10. If the temporary bonding material is a temporary bonding glue, the temporary bonding glue can be coated on the surface of the substrate to form a temporary bonding layer.

[0048] In this embodiment, the temporary bonding material can be a temporary bonding glue or an inorganic substance with adhesion and can be decomposed. For example, the temporary bonding material can be a material that can be softened at high temperature, such as WLP TB130 and WLP TB140. During debonding, the substrate can be peeled off by applying shear force. The temporary bonding material can also be a material that can be decomposed by ultraviolet light, such as WLP LB210 and WLP TB4130. The material can be decomposed by ultraviolet light irradiation to achieve debonding. The temporary bonding material can also be propylene carbonate, etc., which can be dissolved in solvents such as sulfuric acid and acetone to achieve debonding.

[0049] S3, fixing a plurality of chips 30 on a surface of the temporary bonding layer 20 facing away from the substrate 10; wherein a gap exists between two adjacent chips 30.

[0050] Specifically, when the plurality of chips 30 are fixed to the temporary bonding layer 20, the following is formed: Figure 2c The structure shown, in which Figure 2cThe structure of the two chips 30 is only for illustration, and the number of chips 30 can also be 3, 4 or more. Among them, the multiple chips 30 can be different or the same. When the multiple chips 30 are fixed to the surface of the temporary bonding layer 20 facing away from the substrate 10, the surface where the pins are located is away from the temporary bonding layer 20. In this way, the multiple chips 30 can be integrated without the substrate 10, and then the substrate 10 can be peeled off after the multiple chips 30 are integrated, so as to further thin the flexible electronic device and make it suitable for scenes with high thickness requirements.

[0051] It is understandable that when multiple chips 30 are integrated, since the chip 30 itself is a rigid structure, the whole directly formed by the multiple chips 30 is also a rigid structure, which is difficult to achieve flexibility. Therefore, during processing, the multiple chips 30 can be spaced apart so that there is a gap between two adjacent chips 30. Then, a flexible material with adhesive properties can be filled in the gap, so that the multiple chips 30 are flexible after integration. Among them, the size of the gap between the multiple chips 30 can be the same or different, which can be determined according to the number of chips 30 to be integrated or the degree of flexibility. For example, if the flexibility requirements of the flexible electronic device are high, the gap between the two adjacent chips 30 can be larger, so that the flexible electronic device has higher flexibility and is suitable for scenes where the flexible electronic device needs to be bent; in scenes where the flexibility requirements are low, the gap between the two adjacent chips 30 can be smaller, so that the flexible electronic device can maintain a certain rigidity.

[0052] The multiple chips 30 may be multiple heterogeneous chips or the same chips, which does not affect the flexibility of the chip 30 integration process.

[0053] S4 , using a liquid flexible high molecular polymer 40 to fill the gap between every two adjacent chips 30 in the plurality of chips 30 , so as to achieve flexible connection between the plurality of chips 30 .

[0054] In this embodiment, after the plurality of chips 30 are fixed, the gap between every two adjacent chips 30 in the plurality of chips 30 can be filled with a liquid flexible polymer 40. The liquid flexible polymer 40 can be a material with adhesive properties. The plurality of chips 30 can be bonded by the liquid flexible polymer 40, thereby realizing a flexible connection between the plurality of chips 30, forming a Figure 2d The structure shown.

[0055] The liquid flexible high polymer 40 may be directly filled into the gap, or a coating method may be used to form a polymer layer so that part of the gap is filled and part of the gap is covered on the surface of the chip 3, and then the liquid flexible high polymer 40 on the surface of the chip 30 is removed. In this way, the polymer layer filled in the gap is more uniform, which is conducive to large-scale manufacturing.

[0056] It is understandable that the integration of multiple chips 30 requires not only physical connection but also electrical connection. The pins of the multiple chips 30 can be connected by metal wiring. For example, the connection method can be to prepare a metal layer on the surface of the gap-filling area of ​​the liquid flexible polymer 40, and connect the pins of two adjacent chips 30 by etching a metal pattern on the metal layer.

[0057] S5, performing a debonding process on the temporary bonding layer 20 to peel off the substrate 10 to obtain a flexible electronic device.

[0058] Specifically, after the multiple chips 3 are flexibly connected, a debonding process can be used to invalidate the temporary bonding layer 2, thereby separating the substrate 1 from the chip 3 to form a Figure 2f In the structure shown, since a plurality of chips 3 are flexibly connected, the electronic device after the substrate is peeled off is flexible, and the flexible substrate 1 is not required to realize the flexibility of the electronic device.

[0059] Among them, the specific treatment method of the debonding treatment can be determined according to the properties of the temporary bonding material. For example, if the temporary bonding material is a pyrolysis material, heating is used for debonding; if the temporary bonding material is a soluble material, wet dissolution is used; if the temporary bonding material is a photodecomposable material, light is used for debonding.

[0060] By adopting the processing method of the flexible electronic device provided in this embodiment, the flexibility of the electronic device can be achieved without the need for the substrate 10. Moreover, since the substrate 10 is not required, the thickness of the flexible electronic device is further reduced, making it suitable for scenarios with high thickness requirements. In addition, since the processing method of the flexible electronic device is simple, the substrate 10 can be reused, which is suitable for large-scale manufacturing of flexible electronic devices.

[0061] It can be understood that in order to facilitate the electrical connection between the multiple chips 30, it is necessary to interconnect the pins of the multiple chips 30. Therefore, when the chip 30 is fixed to the substrate 10, the side of the chip 30 away from the pin is fixed to the temporary bonding layer 20. In this way, it is convenient to directly connect the pins of the multiple chips 30 without realizing the connection on the other side of the substrate 10, which facilitates the subsequent peeling of the substrate.

[0062] Specifically, the process may include: using a chip mounter or a flip-chip bonding machine to connect a surface of the chip 30 away from the chip pins to the temporary bonding layer 20 , so as to temporarily bond the chip 30 to the substrate 10 .

[0063] Among them, the connection position of each chip 30 and the temporary bonding layer 20 can be designed in advance, such as determining the fixed position of each chip 30 according to the required gap size, the size of the chip 30 and the number of chips 30, and then temporarily bonding the chip 30 to the substrate 10. This is helpful to control the gap size between two adjacent chips 30, thereby controlling the flexibility of the electronic device to suit different scenarios.

[0064] In one embodiment, the connection of multiple chips 30 includes physical connection and electrical connection, wherein the physical connection is achieved by filling liquid flexible polymer in the gap, and the electrical connection is achieved by etching a metal pattern on the chip surface. The process may be specifically as follows: first, a preset process is used to uniformly fill the liquid flexible polymer 40 in multiple gaps, and the surface of the liquid flexible polymer 40 is flattened; then, a metal layer is formed on the side of the multiple chips 30 facing away from the substrate 10, and the metal layer is etched to obtain multiple first metal patterns 50; wherein each first metal pattern 50 is configured to electrically connect two adjacent chips 30.

[0065] Specifically, when the liquid flexible polymer 40 is directly filled into the gap between two adjacent chips, it may cause uneven distribution of the filled liquid flexible polymer 40, thereby affecting the performance of the flexible electronic device. Moreover, in the case of integration of multiple chips 30, filling multiple gaps separately will easily make the properties of the liquid flexible polymer 40 filled in different gaps different, making the performance of the flexible electronic device difficult to control. Therefore, uniform filling can be performed through a preset process to ensure the performance of the flexible electronic device finally prepared.

[0066] The preset process is a process that can achieve uniform filling of the liquid flexible high molecular polymer 40, such as chemical vapor deposition, spin coating and other processes. It can be understood that when the preset process is used to fill the gap with the liquid flexible high molecular polymer 40, filling multiple gaps together can better control the uniformity of the filled liquid flexible high molecular polymer 40. Therefore, the preset process can be used to prepare a bonding layer formed by the liquid flexible high molecular polymer 40 on the side of the chip away from the substrate. In this way, the properties of the entire layer can be made consistent, avoiding the situation where the uniformity is difficult to ensure due to separate filling.

[0067] In one embodiment, the predetermined process includes any one of a dry film lamination process, a chemical vapor deposition process, and a spin coating process.

[0068] Among them, the dry film lamination process is a method of combining a dry film with other material layers into a whole by applying pressure or heating. Chemical vapor deposition is a method of using one or several gaseous compounds or simple substances containing film elements to react chemically on the surface of a substrate to generate a thin film. The spin coating process is a method of directly coating the slurry on the surface of the material to form a film layer. These methods can all form a uniform thin film on the surface of the substrate, thereby removing the liquid flexible polymer on the surface of the chip, and evenly filling the liquid flexible polymer in the gap.

[0069] For example, when the preset process is a dry film lamination process, the already formed polymer film can be pressed onto the surface of the substrate, and the thickness of the pressed dry film can be determined according to the thickness of the chip so as to fill the gap between two adjacent chips. After the polymer film covers the surface of the substrate, the polymer film on the surface of the chip is removed; when the preset process is a chemical vapor deposition process, the polymer monomer is deposited on the surface of the fixed chip, and reacted to form a polymer film, thereby filling the gap between two adjacent chips; when the preset process is a spin coating process, a liquid flexible polymer is coated on the surface of the substrate where the chip has been fixed, and annealed to form a dielectric layer, and then the liquid flexible polymer on the surface of the chip is removed to fill the gap between two adjacent chips.

[0070] In this embodiment, Figure 2e As shown, after filling with liquid flexible high molecular polymer 40, multiple chips 30 are physically connected, but integration cannot be achieved, and multiple chips 30 need to be electrically connected. At this time, a metal layer can be first formed on the side of the chip 30 away from the substrate 10, and the electrical connection between two adjacent chips 30 can be achieved by etching a first metal pattern in the metal layer. It can be understood that in order to ensure the flatness of the formed metal layer and facilitate the etching of the metal pattern, the surface of the liquid flexible high molecular polymer filling the gap can be flattened first, and then a metal layer is formed, and the first metal pattern 40 is etched in the metal layer to achieve electrical connection between multiple chips.

[0071] It is understandable that if a metal layer is directly formed to etch a metal pattern after filling the liquid flexible polymer 40, the surface of the filled portion of the liquid flexible polymer 40 is not smooth, which will affect the etching process. Therefore, before etching the metal traces, the surface of the liquid flexible polymer 40 needs to be flattened, wherein the surface flattening process can be a chemical mechanical polishing process or a photoresist back-etching process. The chemical mechanical polishing process uses mechanical force to act on the surface to be polished, and at the same time, the chemical substances in the polishing liquid react chemically with the surface material to increase its polishing rate, thereby achieving surface flattening, while the photoresist back-etching process is a process that uses photoresist coated on the surface to be flattened to etch it to achieve flattening.

[0072] After etching to obtain a plurality of first metal patterns 50, the following is obtained: Figure 2e In the structure shown, the orthographic projection of each first metal pattern 50 on the surface of the substrate 10 overlaps with the orthographic projection of two adjacent chips 30 on the surface of the substrate 10, and covers the orthographic projection of the liquid flexible polymer 40 in the gap on the surface of the substrate 10. In this way, the first metal pattern 50 realizes the electrical connection between the two adjacent chips 30, and when the number of chips 30 is more than two, the electrical connection between multiple chips 30 is realized by interconnecting two adjacent chips 30 in pairs.

[0073] In one embodiment, continue to refer to Figure 2e , a connection area (not shown in the figure) is formed on the surface of the liquid flexible high molecular polymer 40, and the orthographic projection of the connection area on the surface of the substrate 10 overlaps with the orthographic projection of the liquid flexible high molecular polymer 40 filling the gap on the surface of the substrate 10; the metal layer can also be etched to obtain a second metal pattern 60, the orthographic projection of the second metal pattern 60 on the surface of the substrate 10 at least partially overlaps with the orthographic projection of the chip 30 adjacent to the connection area on the surface of the substrate 10, and the second metal pattern 60 extends into the connection area. Thus, the connection area can cover at least part of the second metal pattern 60, so that it can be connected to other electronic devices through the connection area.

[0074] In this embodiment, in order to realize the connection between the chip 30 and other electronic devices through the connection area, a second metal pattern 60 can be etched in the area of ​​the chip close to the connection area. Since the second metal pattern 60 extends to the connection area, other electronic devices can be connected to the second metal pattern 60 in the connection area, thereby being electrically connected to multiple chips 30.

[0075] For any of the above embodiments, the thickness of the portion of the liquid flexible polymer 40 filling the gap in the target direction is greater than the thickness of the plurality of chips 30 in the target direction, so that it is convenient to connect two adjacent chips on the surface of the liquid flexible polymer filling position. The target direction is the direction from the substrate 10 to the chip 30. Figure 2f For example, the target direction is the direction indicated by the coordinate axis y. For example, the thicknesses of the plurality of chips 30 in the y-axis direction are 100 μm, 200 μm and 500 μm respectively, and the filling thickness of the liquid flexible polymer 40 can be 550 μm, 600 μm and so on.

[0076] The liquid flexible high molecular polymer may be one of polyimide and polyparaxylene. During filling, the polyimide forms a polyimide film and the polyparaxylene forms a polyparaxylene film.

[0077] In one embodiment, the debonding process includes any one of a thermal decomposition process, a wet dissolution process, and a photodecomposition process.

[0078] The debonding treatment method may be determined according to the properties of the temporary bonding material used in the temporary bonding layer.

[0079] For example, if the temporary bonding material is an ultraviolet light-decomposable material, the temporary bonding layer can be photodecomposed by ultraviolet light irradiation to peel off the substrate and obtain a flexible electronic device; if the temporary bonding material is a thermally decomposable material, the temporary bonding layer can be thermally decomposed by heating to decompose the temporary bonding layer, thereby separating the substrate from the flexible electronic device; if the temporary bonding material is a soluble material, the processed substrate can be immersed in a chemical solvent, and the temporary bonding layer can be dissolved by the chemical solvent to separate the flexible electronic device from the substrate.

[0080] The processing method of the flexible electronic device provided in this embodiment temporarily bonds multiple chips to a substrate, and uses a flexible polymer on the substrate to fill the gaps between the multiple chips. Since the flexible polymer has adhesive properties, flexible connection of the multiple chips can be achieved. After the connection, the substrate and the multiple chips are peeled off by debonding treatment. In this way, the processed flexible electronic device may not include a substrate. Therefore, the flexibility of the electronic device can be achieved without the help of a substrate, and the thickness of the flexible electronic device can be further reduced. At the same time, the processing method is simple and can be suitable for large-scale manufacturing.

[0081] Next, combine Figure 2a-2f The processing method of the flexible electronic device provided by the embodiment of the present invention is specifically introduced:

[0082] First, a substrate 10 is prepared. The structure of the substrate 10 is as follows: Figure 2aAs shown, the substrate 10 can be a silicon wafer or a glass wafer. The shape of the substrate 10 can be selected according to the shape of the flexible electronic device. For example, if the flexible electronic device is circular, the surface of the substrate 10 is also circular; if the flexible electronic device is rectangular, the surface of the substrate 10 is also rectangular, and so on.

[0083] Next, a temporary bonding adhesive is coated on the surface of the substrate 10 to form a temporary bonding layer 20. Figure 2b The structure shown in FIG. 1 is a structure in which the temporary bonding layer 20 covers the entire surface of the substrate 10; then, a plurality of chips 30 are fixed to fixed positions of the temporary bonding layer 20 by a chip mounter or a flip-chip bonding machine, so that there is a gap between two adjacent chips 30, such as Figure 2c As shown, the surface of one side of the chip 30 where the pins are located is away from the substrate 10. Wherein, when a plurality of chips 30 are fixed to the temporary bonding layer 20, the gaps between every two adjacent chips 30 may be the same or different, and the specific gap size may be determined according to the surface area of ​​each chip 30, the surface area of ​​the substrate 10 and the total number of the plurality of chips 30.

[0084] After the chip 30 is temporarily bonded to the surface of the substrate 10, a PI (Polyimide) film is pressed on the surface of the substrate 10 by a dry film lamination process, and the PI film on the surface of the chip 30 is removed, so that the PI film fills the gap between two adjacent chips 30. Figure 2d As shown, the PI film has adhesive properties and is a flexible material, thereby achieving flexible connection between multiple chips 30.

[0085] After the PI film is used to fill the gap, the surface of the PI film is flattened and a metal layer is formed on the surface of the PI film, and the metal layer is etched to obtain a first metal pattern 50. At the same time, a connection area is formed on the surface of the PI film, and a second metal pattern 60 is etched near the connection area of ​​the chip 30. Thus, two adjacent chips 30 can be connected through the first metal pattern 50, and multiple chips 30 can be connected to other electronic devices through the second metal pattern 60 located in the connection area. Figure 2e As shown, the orthographic projection of the first metal pattern 50 on the surface of the substrate 10 overlaps with the orthographic projections of its two adjacent chips 30 on the surface of the substrate 10, and the orthographic projection of the first metal pattern 50 covers the PI film in the gap, while the second metal pattern 60 extends to the connection area.

[0086] Afterwards, the debonding method is determined according to the properties of the temporary bonding adhesive, and the debonding process is performed to make the temporary bonding layer invalid, thereby peeling off the multiple chips connected flexibly from the substrate to obtain a flexible electronic device. The structure of the flexible electronic device is as follows: Figure 2f The debonding treatment may be a thermal decomposition treatment, a photodecomposition treatment or a wet dissolution treatment.

[0087] Based on the same inventive concept, an embodiment of the present invention provides a flexible electronic device, which is manufactured by the manufacturing method of the flexible electronic device described in any of the above embodiments.

[0088] The flexible electronic device provided in this embodiment realizes the connection between two adjacent chips through liquid flexible polymer, so that the formed electronic device can be flexible without a substrate. Therefore, the thickness of the flexible electronic device is further reduced by removing the substrate, so that it can be used in scenarios with high thickness requirements.

[0089] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0090] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0091] The above is a detailed introduction to a processing method of a flexible electronic device and a flexible electronic device provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technicians in this field, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present invention.

[0092] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The description and examples are to be regarded as exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

[0093] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

[0094] References herein to "one embodiment," "embodiment," or "one or more embodiments" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present disclosure. In addition, please note that examples of the term "in one embodiment" do not necessarily all refer to the same embodiment.

[0095] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0096] In the claims, any reference signs placed between brackets shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third etc. does not indicate any order. These words may be interpreted as names.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for processing a flexible electronic device, characterized in that: The method comprises: providing a substrate; Preparing a temporary bonding layer on one side surface of the substrate; Fixing a plurality of chips on a surface of the temporary bonding layer facing away from the substrate, wherein there is a gap between two adjacent chips; Filling the gap between every two adjacent chips in the plurality of chips with a liquid flexible high molecular polymer to achieve flexible connection between the plurality of chips; The temporary bonding layer is subjected to a debonding process to peel off the substrate to obtain the flexible electronic device.

2. The method for processing a flexible electronic device according to claim 1, characterized in that: The method of filling the gap between every two adjacent chips in the plurality of chips with a liquid flexible high molecular polymer comprises: Using a preset process to uniformly fill the liquid flexible polymer in the plurality of gaps, and flattening the surface of the liquid flexible polymer; A metal layer is formed on a side of the plurality of chips facing away from the substrate, and the metal layer is etched to obtain a plurality of first metal patterns; wherein each first metal pattern is configured to electrically connect two adjacent chips.

3. The method for processing a flexible electronic device according to claim 2, characterized in that: The orthographic projection of each of the first metal patterns on the surface of the substrate overlaps with the orthographic projections of two adjacent chips on the surface of the substrate, and covers the orthographic projections of the liquid flexible high molecular polymer in the gap on the surface of the substrate.

4. The method for processing a flexible electronic device according to claim 2, characterized in that: A connection area is formed on the surface of the liquid flexible high molecular polymer, and the orthographic projection of the connection area on the surface of the substrate overlaps with the orthographic projection of the liquid flexible high molecular polymer filling the gap on the surface of the substrate; The method further comprises: The metal layer is etched to obtain a second metal pattern, wherein the orthographic projection of the second metal pattern on the surface of the substrate at least partially overlaps with the orthographic projection of the chip adjacent to the connection area on the surface of the substrate, and the second metal pattern extends into the connection area.

5. The method for processing a flexible electronic device according to claim 2, characterized in that: The preset process includes any one of a dry film lamination process, a chemical vapor deposition process and a spin coating process.

6. The method for processing a flexible electronic device according to claim 1, characterized in that: The step of fixing the plurality of chips on a surface of the temporary bonding layer facing away from the substrate comprises: A chip mounter or a flip-chip bonding machine is used to connect a surface of the chip away from the chip pins with the temporary bonding layer, so as to temporarily bond the chip to the substrate.

7. The method for processing a flexible electronic device according to claim 1, characterized in that: The thickness of the portion of the liquid flexible high molecular polymer filling the gap in a target direction is greater than or equal to the thickness of the plurality of chips in the target direction, and the target direction is the direction from the substrate to the chip.

8. The method for processing a flexible electronic device according to claim 1, characterized in that: The liquid flexible high molecular polymer includes at least one of polyimide and polyparaxylene.

9. The method for processing a flexible electronic device according to claim 1, characterized in that: The debonding treatment includes any one of a thermal decomposition treatment, a wet dissolution treatment, and a photodecomposition treatment.

10. A flexible electronic device, characterized in that: The flexible electronic device is obtained by processing using the processing method of any one of claims 1 to 9.

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