Chip transfer method

Abstract

This application discloses a chip transfer method. The method involves forming a fixing layer with a first melting point on the side of multiple chips facing away from the substrate, aligning a driving backplate with the substrate, and cooling the driving backplate so that its temperature is less than or equal to the first melting point. This causes the fixing layer covering the chips to melt, separating the chips covered with the molten fixing layer from the substrate. The moment a chip falls onto the driving backplate, because the temperature of the driving backplate is less than or equal to the first melting point, the molten fixing layer covering the chip solidifies, fixing the chip to the driving backplate. This prevents the chip from falling to other positions, i.e., avoids chip flipping or positional displacement, thus improving the transfer yield.

Description

Technical Field

[0001] This application relates to the field of chip transfer technology, specifically to a chip transfer method. Background Technology

[0002] With the gradual development of display technology, Micro-LED (Micro Light Emitting Diode) technology is being mentioned more and more. Micro-LED is a miniaturized LED (Light Emitting Diode) with a size between 1um and 100um. It is currently the most promising next-generation semiconductor display technology to replace LCD (Liquid Crystal Display) and OLED (Organic Light Emitting Diode).

[0003] After the Micro-LED chip is fabricated, millions or even tens of millions of micron-sized LED chips need to be correctly and efficiently moved to the driver backplane. This process is called "mass transfer". However, when transferring LED chips to the driver backplane, LED chips are prone to problems such as flipping or deviating from the target position, which leads to failure to properly bond to the driver backplane and affects the transfer yield. Summary of the Invention

[0004] This application discloses a chip transfer method to improve the yield of chip transfer to a driver backplane.

[0005] This application discloses a chip transfer method, the method comprising:

[0006] Provides a substrate with multiple chips;

[0007] A fixing layer having a first melting point is formed on the side of the plurality of chips facing away from the substrate;

[0008] A drive backplate is provided, and the drive backplate is cooled so that the temperature of the drive backplate is less than or equal to the first melting point;

[0009] Align the drive backplate with the substrate;

[0010] The chip is separated from the substrate and the fixing layer on the chip is melted. The chip solidifies by contacting the driving backplate through the fixing layer to fix it to the driving backplate.

[0011] As an optional implementation, the melting point of the fixing layer is 35°C to 85°C, and the temperature of the drive backplate after cooling treatment is -20°C to 35°C.

[0012] As an optional implementation, after separating the chip from the substrate and melting the fixing layer on the chip, and solidifying the chip through the fixing layer to fix it to the driving backplane, the method further includes:

[0013] Heating the drive backplane and / or the chip on the drive backplane to solder the chip to the drive backplane and to vaporize and volatilize the fixing layer by heating.

[0014] As an optional implementation, the boiling point of the fixed layer is b, and the heating temperature of the heating of the driving backplate and / or the chip on the driving backplate is a, wherein 150℃≤b<a≤300℃.

[0015] As an optional implementation, separating the chip from the substrate and melting the fixing layer on the chip includes:

[0016] A laser is applied to the substrate to separate the chip from the substrate;

[0017] The substrate is heated to melt the fixing layer on the chip.

[0018] As an optional implementation, heating the substrate to melt the fixing layer on the chip includes:

[0019] Provide heating device;

[0020] The heating device is attached to the side of the substrate away from the chip to heat the substrate, so that the fixing layer melts.

[0021] As an optional implementation, the heating device has a through opening, which is correspondingly positioned to correspond to the chip;

[0022] The step of applying a laser to the substrate to separate the chip from the substrate includes:

[0023] Provide lasers;

[0024] The laser is aimed at the opening and emitted to separate the chip from the substrate.

[0025] As an optional implementation, forming a fixing layer having a first melting point on the side of the plurality of chips facing away from the substrate includes:

[0026] A molten fixing material is provided, wherein the melting point of the fixing material is the first melting point;

[0027] The molten fixing material is sprayed or spin-coated onto the side of the plurality of chips facing away from the substrate to form the fixing layer.

[0028] As an optional implementation, the step of spraying or spin-coating the molten fixing material onto the side of the plurality of chips facing away from the substrate to form the fixing layer includes:

[0029] The substrate is heated to make the temperature of the substrate and the plurality of chips on the substrate greater than or equal to the first melting point.

[0030] The molten fixing material is sprayed or spin-coated onto the side of the plurality of chips facing away from the substrate;

[0031] The substrate is cooled to solidify the fixing material to form the fixing layer on the plurality of chips.

[0032] As an alternative implementation, the substrate is a growth substrate, or the substrate is a temporary carrier.

[0033] Compared with related technologies, the embodiments of this application have the following beneficial effects:

[0034] This application provides a chip transfer method. The method involves forming a fixing layer with a first melting point on the side of multiple chips facing away from the substrate, aligning a driving backplate with the substrate, and cooling the driving backplate so that its temperature is less than or equal to the first melting point. This causes the fixing layer covering the chips to melt, separating the chips covered with the molten fixing layer from the substrate. The moment the chip falls onto the driving backplate, because the temperature of the driving backplate is less than or equal to the first melting point, the molten fixing layer covering the chip solidifies, fixing the chip to the driving backplate. This prevents the chip from falling to other positions, i.e., avoids chip flipping or positional displacement, thus improving the transfer yield. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the chip flipping and position offset in related technologies;

[0037] Figure 2 This is a schematic flowchart of a chip transfer method disclosed in an embodiment of this application;

[0038] Figure 3 for Figure 2 A schematic diagram illustrating the chip transfer method in the diagram;

[0039] Figure 4 This is a schematic diagram of the process for forming a fixed layer disclosed in an embodiment of this application;

[0040] Figure 5 This is a schematic diagram of the process of chip detachment and melting of the fixing layer disclosed in the embodiments of this application;

[0041] Figure 6 This is another schematic flowchart of the chip transfer method disclosed in the embodiments of this application;

[0042] Figure 7 This is another schematic flowchart of the chip transfer method disclosed in the embodiments of this application. Detailed Implementation

[0043] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] It should be noted that the terms "comprising" and "having," and any variations thereof, in the embodiments and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0045] Compared to OLED and LCD, Micro-LED offers higher luminous efficiency, longer lifespan, higher brightness, and faster response time, while also boasting advantages such as thinness and energy efficiency. Micro-LED technology is considered a key option for the next generation of mainstream display technology.

[0046] After fabricating micron-sized Micro-LED chips, millions or even tens of millions of these chips need to be correctly and efficiently transferred to a driver backplane—a process known as "mass transfer." Currently, mass transfer technologies include flexible stamp transfer, laser transfer, and fluid self-assembly. Compared to other mass transfer technologies, laser transfer offers high controllability, high efficiency, ease of processing, and flexibility. However, during the laser transfer process, a certain gap is generally required between the LED chip and the backplane to prevent the chip bonded to the substrate from damaging the drive circuitry on the backplane. However, due to the high rigidity of the backplane (usually a glass backplane or printed circuit board), after the LED chip is separated from the backplane by laser, it may fall onto the backplane and collide with it, causing the chip to flip or shift. For example... Figure 1 As shown, the first chip 110c flips over, and the side of the first chip 110c with electrode 111 moves away from the driving backplate 120. The second chip 110d shifts position, and neither the first chip 110c nor the second chip 110d can be properly bonded to the driving backplate 120.

[0047] In view of this, embodiments of this application provide a chip transfer method. This chip transfer method involves forming a fixing layer with a first melting point on the side of multiple chips facing away from the substrate, aligning a driving backplate with the substrate, and cooling the driving backplate so that its temperature is less than or equal to the first melting point, causing the fixing layer covering the chips to melt. The chips covered with the molten fixing layer are then separated from the substrate. At the instant the chip falls onto the driving backplate, because the temperature of the driving backplate is less than or equal to the first melting point, the molten fixing layer covering the chip solidifies, fixing the chip onto the driving backplate. This prevents the chip from falling to other positions, i.e., avoids chip flipping or positional displacement, and improves the transfer yield.

[0048] Please refer to Figure 2 This application illustrates a chip transfer method provided by an embodiment of the present application, such as... Figure 2 As shown, the chip transfer method may include steps S202 to S210. Specifically, the chip transfer method may include:

[0049] S202: Provides a substrate with multiple chips.

[0050] Please refer to Figure 3 (a) shows a schematic diagram of a substrate with multiple chips, such as Figure 3As shown in (a), a plurality of chips 110 are disposed on the substrate 311. Optionally, the chips 110 can be Micro-LED chips. Optionally, the chips 110 disposed on the substrate 311 can be upright Micro-LED chips or flip-chip Micro-LED chips. Optionally, the chips 110 disposed on the substrate 311 can be red Micro-LED chips, green Micro-LED chips, or blue Micro-LED chips.

[0051] In an optional embodiment, the substrate 311 can be a temporary carrier, i.e., a substrate with multiple chips, including: providing a growth substrate with multiple chips, detaching the multiple chips from the growth substrate, and bonding the multiple chips to the temporary carrier. Then, the chip 110 is detached from the temporary carrier and dropped onto a driving backplane, thereby achieving contact between the electrodes of the chip 110 and the electrodes of the driving backplane, realizing bonding. The growth substrate provides growth space for the multiple chips 110. Considering that before transferring the chip 110 from the temporary carrier to the driving backplane, the side of the chip 110 with electrodes should face away from the temporary carrier to achieve contact between the electrodes of the chip 110 and the electrodes of the driving backplane, preparing for bonding between the chip 110 and the driving backplane. It is understandable that if the growth substrate is away from the side of the chip 110 with electrodes, and a temporary carrier is used to transfer the chip 110 to the driving backplane, two temporary carriers should be used; if the growth substrate is close to the side of the chip 110 with electrodes, and a temporary carrier is used to transfer the chip 110 to the driving backplane, one temporary carrier is sufficient.

[0052] Optionally, the temporary carrier may include an adhesive layer and a carrier, wherein the adhesive layer has adhesive force and is connected to one side of the carrier. Optionally, the adhesive layer is made of UV (Ultraviolet Rays) adhesive that reacts with a laser. By using UV adhesive as the material of the adhesive layer, the adhesion between the adhesive layer and the chip 110 can be adjusted by the laser to enable the adhesive layer to pick up or release the chip 110, thereby enabling the chip 110 to adhere to or detach from the temporary carrier.

[0053] In another optional embodiment, the substrate 311 can be a growth substrate, i.e., a substrate with multiple chips, including: providing a growth substrate with multiple chips. In this embodiment, the side of the chip 110 with electrodes faces away from the growth substrate. The chip 110 is detached from the growth substrate and falls onto a driving backplane, thereby achieving contact between the electrodes of the chip 110 and the electrodes of the driving backplane, thus achieving bonding. The substrate 311 is a growth substrate, meaning this embodiment provides a method to directly transfer multiple chips 110 from the growth substrate to the driving backplane without using a temporary carrier, making the chip transfer process simpler and less difficult to develop (chip transfer places high demands on the uniformity, adhesion, and Young's modulus of the adhesive layer on the temporary carrier). Optionally, the multiple chips 110 are arranged in an array on the growth substrate.

[0054] S204: A fixing layer with a first melting point is formed on the side of multiple chips facing away from the substrate.

[0055] Please refer to Figure 3 (b) illustrates a schematic diagram of a structure in which a fixed layer is formed on multiple chips, such as Figure 3 As shown in (b), a fixing layer 313 is covered on the side of the plurality of chips 110 facing away from the substrate 311. The fixing layer 313 has a first melting point and a first boiling point. That is, when the temperature of the fixing layer 313 is lower than the first melting point, the fixing layer 313 is solid; when the temperature of the fixing layer 313 is higher than the first melting point but lower than the first boiling point, the fixing layer 313 is molten, that is, the fixing layer 313 is liquid or a solid-liquid coexistence state; when the temperature of the fixing layer 313 is higher than the first boiling point, the fixing layer 313 is gaseous. Optionally, the range of the first melting point can be 35°C to 85°C. For example, the first melting point can be 35°C, 45°C, 55°C, 65°C, 75°C, or 85°C. Optionally, the range of the first boiling point can be 150°C to 300°C. For example, the first boiling point can be 150°C, 180°C, 200°C, 250°C, 270°C, or 300°C.

[0056] Optionally, the fixing layer 313 can be a diphenyl ethane layer or a paraffin layer. Optionally, the fixing layer 313 is a diphenyl ethane layer. Diphenyl ethane has a melting point of 55°C. When the temperature of diphenyl ethane is higher than its boiling point, it will completely vaporize and evaporate (leaving no residue or causing corrosion). Moreover, diphenyl ethane is inert relative to metals, that is, diphenyl ethane will not react with metals.

[0057] Optionally, the fixing layer 313 covers at least one side of the plurality of chips 110 opposite to the substrate 311. Please refer to [link / reference needed]. Figure 3(b) Exemplarily, the fixing layer 313 may surround a plurality of chips 110, that is, the fixing layer 313 covers not only the side of the chip 110 facing away from the substrate, but also the outer periphery of the chip 110. Optionally, the thickness of the fixing layer 313 covering the chip 110 may be less than the thickness of the chip 110. Exemplarily, the thickness of the fixing layer 313 is less than 10 micrometers.

[0058] Furthermore, considering that the fixing layer 313 covers the chip 110, the process of forming the fixing layer on the chip may include: providing molten fixing material (which is the material of the fixing layer that melts at a first melting point), and spraying or spin-coating the molten fixing material onto the side of the plurality of chips away from the substrate to form the fixing layer.

[0059] Please refer to Figure 4 It illustrates a fixed layer forming method provided in an embodiment of this application, such as... Figure 4 As shown, the detailed steps of spraying or spin-coating molten fixing material onto the side of multiple chips away from the substrate to form a fixing layer may include steps S402 to S406.

[0060] S402, heat the substrate to make the temperature of the substrate and the multiple chips on the substrate greater than or equal to the first melting point.

[0061] In this step, when the substrate is heated, a heating device can be provided to attach to the side of the substrate away from the chip, so that the heating device can release heat to heat the substrate and the chip on the substrate.

[0062] S404 involves spraying or spin-coating molten fixative material onto the side of multiple chips facing away from the substrate.

[0063] For example, spraying molten fixative material onto the side of multiple chips away from the substrate includes: using a spray gun or a butterfly atomizer, by means of pressure or centrifugal force, dispersing the molten fixative material into uniform and fine droplets, and coating the multiple chips onto the side away from the substrate.

[0064] For example, spin-coating molten fixative material onto the side of multiple chips away from the substrate includes: dripping molten fixative material onto the center of the side of each chip away from the substrate using a syringe, causing the substrate to rotate, thereby causing the molten fixative material to diffuse on the side of the chip away from the substrate, and thus covering the side of the chip away from the substrate.

[0065] S406, cools the substrate to solidify the fixing material to form a fixing layer on multiple chips.

[0066] It should be noted that cooling the substrate refers to lowering the temperature of the multiple chips disposed on the substrate from a first temperature (greater than or equal to the first melting point) to a second temperature (less than the first melting point), so that the fixing material sprayed or spin-coated onto the multiple chips can solidify. For example, when the room temperature is below the first melting point, cooling the substrate includes placing the substrate in a room temperature environment for static cooling. Placing the substrate in a room temperature environment without heating it allows the substrate and the multiple chips to gradually cool, meaning the temperature of the fixing material will slowly decrease, thereby solidifying on the multiple chips to form a fixing layer. In this embodiment, a solid fixing layer is formed on the side of the multiple chips facing away from the substrate. Compared to a molten fixing layer, this avoids unexpected detachment of the fixing layer (such as the fixing layer dripping outside the drive backplate during the process of moving the drive backplate and / or the substrate to align the drive backplate with the substrate), thus preventing resource waste.

[0067] In this embodiment, the substrate is heated before the molten fixing material is sprayed or spin-coated onto the side of the multiple chips away from the substrate. This heats the substrate and the multiple chips disposed on the substrate to a temperature greater than or equal to the first melting point. As a result, when the fixing material is applied to the side of the multiple chips away from the substrate, the fixing material remains in a molten state. This avoids the inability to form a uniform fixing layer on the chips due to the fixing material solidifying when it is applied to the chips (because if the fixing material applied to the chips solidifies, rotating the substrate will not allow the fixing material to spread on the side of the chips away from the substrate).

[0068] S206 provides a drive backplane and performs a cooling treatment on the drive backplane so that the temperature of the drive backplane is less than or equal to the first melting point.

[0069] It should be noted that the driving backplane may include driving electrodes, which can be used to electrically connect with the electrodes of the chip to achieve the purpose of driving the chip. For example, when the chip is used to achieve light emission, the driving chip is a lighting chip.

[0070] In an optional embodiment, cooling the drive backplane to make its temperature less than or equal to a first melting point may include: providing a cooling device, attaching a first side of the cooling device to a first side of the drive backplane and making the temperature of the first side of the cooling device less than or equal to the first melting point, so that the temperature of the drive backplane is less than or equal to the first melting point.

[0071] As mentioned above, the melting point of the fixing layer can be from 35°C to 85°C. Therefore, the temperature of the drive backplate after cooling treatment can be from -20°C to 35°C. For example, it can be -20°C, 0°C, 20°C or 35°C, as long as the temperature of the drive backplate after cooling treatment is lower than the first melting point of the fixing layer. This embodiment does not make specific limitations on this.

[0072] S208, align the drive backplane with the substrate.

[0073] It should be noted that aligning the drive backplane with the substrate is to enable the chip to detach from the substrate and be positioned approximately corresponding to the electrodes on the drive backplane.

[0074] S210 separates the chip from the substrate and melts the fixing layer on the chip. The chip solidifies by contacting the driving backplane through the fixing layer to fix it to the driving backplane.

[0075] It should be noted that if there are x chips on the substrate, separating the chips from the substrate can be done by separating y chips on the substrate from the substrate, where x≥y≥1. That is, depending on the actual situation, one can choose to separate all the chips on the substrate from the substrate, or one can choose to separate some of the chips on the substrate from the substrate.

[0076] When the chip is transferred to the driving backplane, its position relative to the driving backplane may shift. If the fixing layer is not molten at this time, the Young's modulus of the solid-state fixing layer is larger than that of the molten fixing layer. Therefore, when the chip with the fixing layer on it comes into contact with the driving backplane, it may still flip or shift in position. This application employs a method where the fixing layer on the chip is simultaneously molten during chip separation from the substrate. This allows the molten fixing layer to contact the driving backplane first during chip transfer, and then solidify on the cooling driving backplane upon contact, thus fixing the chip to the driving backplane and preventing positional shift of the chip relative to the driving backplane.

[0077] In an optional embodiment, separating the chip from the substrate and melting the fixing layer on the chip may include: applying a laser to the substrate to separate the chip from the substrate while the fixing layer is heated and melted. In this embodiment, during the process of separating the chip from the substrate using laser transfer technology, the heat generated by the laser melts the fixing layer, thus simplifying the chip transfer process by simultaneously separating the chip from the substrate and melting the fixing layer.

[0078] In another optional embodiment, separating the chip from the substrate and melting the fixing layer on the chip can include: applying a laser to the substrate to separate the chip from the substrate, and heating the substrate to melt the fixing layer on the chip. That is, chip separation from the substrate is achieved by laser action, and fixing layer melting is achieved by heating the substrate. Using different methods to achieve chip separation from the substrate and fixing layer melting can effectively ensure that the chip separates from the substrate only when the fixing layer is in a molten state, avoiding the situation where the chip separates from the substrate before the fixing layer has melted, resulting in poor transfer yield.

[0079] Optionally, heating the substrate to melt the fixing layer on the chip may include: providing a heating device, attaching the heating device to the side of the substrate away from the chip, and heating the substrate to melt the fixing layer. For example, the heating device may include a heating wire that generates heat when energized, releasing heat.

[0080] Please refer to Figure 5 It illustrates a method for chip detachment and fixing layer melting provided in an embodiment of this application, such as... Figure 5 As shown, the detailed steps of separating the chip from the substrate and melting the fixing layer on the chip may include:

[0081] S502 provides a heating device and a laser. The heating device has a through opening that corresponds to the chip.

[0082] It is understandable that the openings in the heating device penetrate the opposite surface of the heating device, and the number of these openings can be consistent with the number of chips to be transferred, so that each opening can correspond to each chip, thereby facilitating the laser to act on the chip through the openings.

[0083] S504 involves attaching a heating device to the side of the substrate away from the chip to heat the substrate, thereby melting the fixing layer.

[0084] S506 aligns the laser with the opening and releases the laser to separate the chip from the substrate.

[0085] This embodiment, by creating an opening on the heating device corresponding to the chip, enables the laser to act on the substrate and the corresponding chip position while the fixing layer is melted by heating. In other words, it is not necessary to remove the heating device before the laser can act on the substrate, and laser transfer can be performed simultaneously during the heating process, thus improving the efficiency of chip transfer.

[0086] It should be noted that there is no necessary order for steps S202 to S210 above. As long as the fixing layer formed on the side of the chip away from the substrate melts before the chip contacts the driving backplate and the temperature of the driving backplate is less than the first melting point, the order of the steps can be selected as needed.

[0087] The chip transfer method provided in this application forms a fixing layer on the side of the chip away from the substrate and melts the fixing layer so that when the chip detaches from the substrate and comes into contact with a drive backplate with a temperature lower than the melting point of the fixing layer, the fixing layer can solidify, thereby fixing the chip to the drive backplate and avoiding the phenomenon of chip flipping or position shifting during transfer, thus improving the transfer yield.

[0088] Please refer to Figure 6 It illustrates the chip transfer method provided in the embodiments of this application. Figure 5 The chip transfer method shown can include, in addition to, the following: Figure 2 In addition to steps S202 to S210, step S212 may also be included. Specifically, step S212 may include:

[0089] S212, heating the drive backplane and / or the chip on the drive backplane to solder the chip to the drive backplane, and heating the fixing layer to vaporize and volatilize.

[0090] It should be noted that heating the driver backplane, heating the chip, or heating both the driver backplane and the chip can achieve metal bonding between the chip and the driver backplane, completing the electrical connection and thus realizing drive control. It should also be noted that the heat generated during the chip-driver backplane soldering process exceeds the boiling point of the fixing layer; that is, during the chip soldering process to the driver backplane, the fixing layer will vaporize and evaporate due to heat.

[0091] In an optional embodiment, the boiling point of the fixing layer is b, and the heating temperature in the driving backplane and / or the chip on the driving backplane is a, wherein 150℃ ≤ b < a ≤ 300℃. Optionally, during the driving backplane and / or the chip on the driving backplane, the fixing layer is inert relative to the metal, that is, the fixing layer does not react with the metal and does not affect the driving function of the driving backplane. Optionally, the fixing layer completely vaporizes and evaporates during the heating and soldering process, which can avoid the existence of residues or corrosion, that is, the fixing layer does not affect the soldering effect.

[0092] In an optional embodiment, heating a chip on a driver backplane to solder the chip to the driver backplane includes: providing a laser, aiming the laser at the side of the chip facing away from the driver backplane, and releasing the laser to heat the chip on the driver backplane. Optionally, the wavelength of the released laser is 980 nm.

[0093] It should be noted that after the chip is transferred to the driver backplane, the driver backplane needs to be moved from the transfer machine to the soldering machine to complete the soldering of the chip and the driver backplane. In this embodiment, the chip and the driver backplane are fixedly connected by the solidification of the fixing layer. As long as the temperature of the fixing layer is kept below its melting point, the chip will not move or fall off during the process of moving the driver backplane from the transfer machine to the soldering machine, thus improving the soldering yield. For example, the melting point of the fixing layer is higher than the ambient temperature. Therefore, during the process of transferring the chip to the driver backplane and then transferring the driver backplane to the soldering backplane, the chip will not experience any problems such as flipping or positional shift.

[0094] The following examples will briefly illustrate the chip transfer method using diphenyl ethane as the material of the fixing layer.

[0095] Please refer to Figure 7This illustrates a chip transfer method provided by an embodiment of the present application, which may include steps S702 to S712.

[0096] S702 provides a growth substrate with multiple chips.

[0097] S704 involves spraying or spin-coating liquid diphenyl ethane onto the side of multiple chips facing away from the growth substrate to form a diphenyl ethane layer.

[0098] S706 provides a drive backplane for aligning the drive backplane with the growth substrate.

[0099] S708, heats the growth substrate to make the temperature of the growth substrate greater than 55°C.

[0100] Optionally, the growth substrate is heated to a temperature of 70°C.

[0101] S710 cools the drive backplane to keep its temperature below 55°C.

[0102] Optionally, the drive backplane can be cooled to 0°C.

[0103] S712 applies a laser to the growth substrate to separate the chip from the growth substrate and drop it onto the driving backplane. The fixing layer covering the chip comes into contact with the driving backplane and solidifies to fix the chip onto the driving backplane.

[0104] In related technologies, to prevent the chip on the growth substrate from damaging the driving circuitry of the driving backplane, a certain gap is typically maintained between the chip on the growth substrate and the driving backplane. However, this can lead to the chip colliding with the driving backplane after separation from the growth substrate, causing the chip to flip or shift position. The chip transfer method provided in this embodiment can ensure the yield of chip transfer without damaging the driving circuitry on the driving backplane. Furthermore, it directly transfers the chip from the growth substrate to the driving backplane without the need for a temporary carrier, simplifying the chip transfer process and eliminating the need to prepare a temporary carrier containing an adhesive layer, thus significantly reducing development difficulty.

[0105] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Those skilled in the art should also recognize that the embodiments described in the specification are optional embodiments, and the actions and modules involved are not necessarily essential to this application.

[0106] In the various embodiments of this application, it should be understood that the sequence number of each process does not necessarily imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0107] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0108] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A chip transfer method characterized by, The method comprises: providing a substrate provided with a plurality of chips; forming a fixing layer with a first melting point on a side of the plurality of chips away from the substrate; providing a driving backboard, and performing a cooling treatment on the driving backboard so that the temperature of the driving backboard is less than or equal to the first melting point; aligning the driving backboard with the substrate; separating the chips from the substrate and melting the fixing layer on the chips, and the chips are solidified by the fixing layer to be fixed on the driving backboard by contacting the driving backboard; after the separating the chips from the substrate and melting the fixing layer on the chips, and the chips are solidified by the fixing layer to be fixed on the driving backboard by contacting the driving backboard, heating the driving backboard and / or the chips on the driving backboard so that the chips are welded on the driving backboard, and the fixing layer is heated and evaporated.

2. The chip transfer method according to claim 1, wherein The melting point of the fixing layer is 35-85℃, and the temperature of the driving backboard after the cooling treatment is -20-35℃.

3. The chip transfer method according to claim 1, wherein The boiling point of the fixing layer is b, and the heating temperature in the heating the driving backboard and / or the chips on the driving backboard is a, wherein 150℃≤b 4. The chip transfer method according to claim 1, wherein The separating the chips from the substrate and melting the fixing layer on the chips comprises: acting laser on the substrate to separate the chips from the substrate; heating the substrate to melt the fixing layer on the chips.

5. The chip transfer method according to claim 4, wherein The heating the substrate to melt the fixing layer on the chips comprises: providing a heating device; heating the substrate on a side of the substrate away from the chips by the heating device to melt the fixing layer.

6. The chip transfer method according to claim 5, wherein The heating device is provided with a through opening corresponding to the chips; The acting laser on the substrate to separate the chips from the substrate comprises: providing a laser; aligning the laser with the opening and releasing laser to separate the chips from the substrate.

7. The chip transfer method according to claim 1, wherein The forming a fixing layer with a first melting point on a side of the plurality of chips away from the substrate comprises: providing a molten fixing material with a melting point of the first melting point; spraying or spin-coating the molten fixing material on a side of the plurality of chips away from the substrate to form the fixing layer.

8. The chip transfer method according to claim 7, wherein The spraying or spin-coating the molten fixing material on a side of the plurality of chips away from the substrate to form the fixing layer comprises: performing a heating treatment on the substrate so that the temperature of the substrate and the plurality of chips on the substrate is greater than or equal to the first melting point; spraying or spin-coating the molten fixing material on a side of the plurality of chips away from the substrate; cooling the substrate so that the fixing material is solidified to form the fixing layer on the plurality of chips.

9. The chip transfer method according to claim 1, wherein The substrate is a growth substrate, or the substrate is a temporary carrier.

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