Chip transfer apparatus, method and display panel

Abstract

The present application relates to a kind of chip transfer device, method and display panel.The chip transfer device includes sample stage, for placing chip carrier plate;Transfer film is arranged in one side of sample stage, and the side close to sample stage of transfer film includes adhesive layer, and the adhesive layer is used to adhere chip;Transfer film has elasticity, can be deformed to contact chip carrier plate under external force and restore shape after the disappearance of external force;Transfer head is set up opposite sample stage, and transfer head includes first displacement module, and first displacement module is used to control transfer head to move to the direction close to or away from sample stage;Transfer head is used to exert external force to the partial area of transfer film, to make the partial area of transfer film deform to the direction close to sample stage.Effective selective transfer can be realized.

Description

Technical Field

[0001] This invention relates to the field of chip transfer, and more particularly to a chip transfer apparatus, method, and display panel. Background Technology

[0002] In the fabrication process of Micro-LED (Micro Light-Dmitting Diode), full-color technology has always been a research focus for professionals. Compared with color conversion (QDs) and lens synthesis, the RGB (Red, Green, Blue) LED (Light-Emitting Diode) scheme requires the transfer of three different colored LED chips. Since the transfer process conditions for different colored chips are different, the stability and accuracy requirements of the transfer process are high. In the traditional process of transferring RGB LED chips, the transfer process is highly complex and it is difficult to perform selective transfer.

[0003] Therefore, how to achieve effective selective transfer is an urgent problem to be solved. Summary of the Invention

[0004] In view of the shortcomings of the above-mentioned related technologies, the purpose of this application is to provide a chip transfer device, which aims to solve the problem that it is difficult to achieve selective transfer in the traditional chip transfer process.

[0005] A chip transfer device, comprising:

[0006] Sample stage, used to place chip carrier boards;

[0007] A transfer film is disposed on one side of the sample stage. The side of the transfer film closest to the sample stage includes an adhesive layer for adhering the chip. The transfer film is deformable under external force to contact the chip substrate and returns to its shape after the external force is removed.

[0008] A transfer head is disposed directly opposite the sample stage. The transfer head includes a first displacement module, which controls the transfer head to move toward or away from the sample stage. The transfer head applies an external force to at least a portion of the transfer membrane to deform the at least a portion of the transfer membrane toward the sample stage.

[0009] The aforementioned chip transfer apparatus can transfer chips from a transient substrate to a transfer film via a transfer head, and then transfer the chips to a circuit board via the transfer film. In some chip transfer processes, the transfer head can make a portion of the transfer film contact the chip carrier and pick up the chip; selective chip transfer can be achieved by using the transfer head in conjunction with the transfer film.

[0010] Optionally, the transfer head further includes a second displacement module, which is used to control the transfer head to move in a plane parallel to the sample stage.

[0011] It is understandable that by making the transfer head movable, the area where the transfer head applies external force to the transfer film can be changed. During the chip transfer process, the chip can be placed in different areas of the transfer film, which is beneficial for chip transfer. Other chips can be transferred to different areas of the transfer film without affecting the chips already on it. When transferring the chips to the circuit board subsequently, multiple chips can be transferred at once, and these chips can be bonded to the circuit board in one go, avoiding the need for separate bonding of multiple chips. Therefore, the chip transfer apparatus of this embodiment can help reduce the number of bonding operations and lower the complexity of the transfer process in some implementations, thus reducing chip damage during bonding, improving chip transfer yield, and the selective picking also facilitates transfer repair.

[0012] Optionally, the sample stage includes a heating device for heating the sample stage to melt the solder on the target substrate placed on the sample stage, wherein the target substrate is a circuit board for receiving the transferred chip.

[0013] Understandably, by setting a heating device on the sample stage, bonding between the chip and the circuit board can be directly achieved after the chip is transferred to the circuit board, which simplifies the bonding process.

[0014] Optionally, the sample stage includes a third displacement module, which is used to control the sample stage to move in a plane parallel to the transfer membrane.

[0015] Understandably, a movable sample stage facilitates alignment of the chip with the corresponding area of ​​the transfer film.

[0016] Optionally, it also includes a clamp and a fourth displacement module;

[0017] The fourth displacement module is used to control the clamp to move towards or away from the sample stage;

[0018] The clamp is located outside the sample stage and is connected to the fourth displacement module. The clamp is used to fix the transfer membrane.

[0019] Understandably, using a fixture to stably set the transfer film, and being able to adjust the distance between the transfer film and the sample stage, is beneficial for chip transfer and ensures a high transfer yield.

[0020] Optionally, the transfer head includes a plurality of movable bump structures, each of which can switch between a first state and a second state;

[0021] The movable bump structure is closer to the sample stage when it is in the first state than when it is in the second state; the movable bump structure in the first state is used to apply an external force to a portion of the transfer film to deform the portion of the transfer film toward the sample stage.

[0022] Understandably, the movable bump structure facilitates selective transfer and improves transfer flexibility in some implementations. It allows for the transfer of other chips to different areas of the transfer film without affecting existing chips on the film. During subsequent transfer to the circuit board, multiple chips can be transferred simultaneously and bonded to the circuit board in one go, avoiding separate bonding of multiple chips. Therefore, the chip transfer apparatus of this embodiment can reduce the number of bonding operations and the complexity of the transfer process in some implementations, thus reducing chip damage during bonding, improving chip transfer yield, and facilitating transfer repair through selective pickup.

[0023] Optionally, the movable bump structure includes:

[0024] A receiving hole is provided inside the transfer head;

[0025] A magnetic material is disposed within the accommodating hole;

[0026] An elastic membrane is disposed at the opening of the receiving hole near the sample stage, and the elastic membrane encloses the magnetic material inside the receiving hole;

[0027] The magnetic material is used to move towards the sample stage under the action of an electromagnetic field, so as to cause the elastic membrane to deform and switch the movable bump structure to the first state; the elastic membrane restores its shape when the magnetic material is not subjected to an electromagnetic field, so as to switch the movable bump structure to the second state.

[0028] Based on the same inventive concept, this application also provides a chip transfer method, comprising:

[0029] Provided the chip transfer apparatus of the above example;

[0030] The chip carrier board containing the first set of chips to be transferred is placed on the sample stage;

[0031] The first displacement module controls the transfer head to apply external force to the first region of the transfer film, and transfers the first group of chips to be transferred to the first region of the transfer film.

[0032] Replace the chip carrier placed on the sample stage with the target carrier;

[0033] The first group of chips to be transferred is transferred from the transfer film to the target substrate.

[0034] The chip transfer method described above utilizes the chip transfer apparatus of the above embodiment to first transfer the chip onto a transfer film, and then transfer it from the transfer film to the target substrate. Based on the structure of the transfer head, the chip can be transferred to any area of ​​the transfer film, enabling selective transfer. Even if other areas of the transfer film already have chips, the first group of chips to be transferred can be transferred onto the transfer film without affecting other chips. In some processes, selective transfer is possible, and all chips on the transfer film can also be transferred at once. This chip transfer method is flexible in application and, in some implementations, helps reduce the number of bonding operations and the complexity of the transfer process. Therefore, it helps reduce chip damage during bonding, improves chip transfer yield, and facilitates transfer repair.

[0035] Optionally, before replacing the chip carrier placed on the sample stage with the target carrier, the method further includes:

[0036] Replace the chip carrier board with the first set of chips to be transferred placed on the sample stage with a chip carrier board with the second set of chips to be transferred.

[0037] The transfer head applies an external force to the second region of the transfer film and transfers the second set of chips to be transferred onto the second region of the transfer film;

[0038] Replace the chip carrier board with the second set of chips to be transferred placed on the sample stage with a chip carrier board with the third set of chips to be transferred.

[0039] The transfer head applies an external force to the third region of the transfer film and transfers the third set of chips to be transferred onto the third region of the transfer film;

[0040] The first region, the second region, and the third region do not overlap.

[0041] It is understandable that by transferring three different sets of chips to different areas of the transfer film in sequence, the three sets of chips can be pre-arranged on the transfer film and transferred to the target substrate in one go, reducing the number of transfers to the target substrate. When the target substrate is a circuit board, the number of bonding operations can also be reduced, and the process complexity of the transfer can be reduced. Therefore, it is beneficial to reduce chip damage during the bonding process, improve the yield of chip transfer, and facilitate transfer repair.

[0042] Based on the same inventive concept, this application also provides a display panel, including a circuit board and a chip;

[0043] The chip is transferred to the die-bonding region of the circuit substrate using the chip transfer method described above, and bonding is completed.

[0044] The chips in the aforementioned display panel are transferred using the chip transfer method described in the example above. This transfer process has low complexity and high yield. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of a chip transfer device provided in an embodiment of the present invention;

[0046] Figure 2 A schematic diagram of the structure of the transfer head provided in an embodiment of the present invention. Figure 1 ;

[0047] Figure 3 This is a schematic diagram of the arrangement of the protrusions on the transfer head provided in an embodiment of the present invention;

[0048] Figure 4 A schematic diagram of the structure of the transfer head provided in an embodiment of the present invention. Figure 2 ;、

[0049] Figure 5 A schematic diagram of the movable bump structure on the transfer head provided in an embodiment of the present invention. Figure 1 ;

[0050] Figure 6 A schematic diagram of the movable bump structure on the transfer head provided in an embodiment of the present invention. Figure 2 ;

[0051] Figure 7 A schematic diagram illustrating the arrangement of the clamp provided in an embodiment of the present invention;

[0052] Figure 8 A flowchart illustrating a chip transfer method provided in another optional embodiment of the present invention. Figure 1 ;

[0053] Figure 9 This is a schematic diagram of the structure of a chip transfer device provided in another optional embodiment of the present invention;

[0054] Figure 10 A detailed flowchart of step S103 provided in another optional embodiment of the present invention;

[0055] Figure 11 A schematic diagram of the transfer process provided for another optional embodiment of the present invention Figure 1 ;

[0056] Figure 12 A schematic diagram of the transfer process provided for another optional embodiment of the present invention Figure 2 ;

[0057] Figure 13 A schematic diagram of the transfer process provided for another optional embodiment of the present invention Figure 3 ;

[0058] Figure 14 A schematic diagram of the transfer process provided for another optional embodiment of the present invention Figure 4 ;

[0059] Figure 15 A schematic diagram of another transfer process provided for another optional embodiment of the present invention;

[0060] Figure 16 A schematic diagram of yet another transfer process provided for another optional embodiment of the present invention;

[0061] Figure 17 A detailed flowchart of step S105 provided in another optional embodiment of the present invention;

[0062] Figure 18 A schematic diagram of the transfer process provided for another optional embodiment of the present invention Figure 5 ;

[0063] Figure 19 A flowchart illustrating a chip transfer method provided in another optional embodiment of the present invention. Figure 2 ;

[0064] Figure 20 A schematic diagram of the transfer process provided for another optional embodiment of the present invention Figure 6 ;

[0065] Figure 21 A schematic diagram of the transfer process provided for another optional embodiment of the present invention Figure 7 ;

[0066] Figure 22 A schematic diagram of the transfer process provided for another optional embodiment of the present invention Figure 8 ;

[0067] Explanation of reference numerals in the attached figures:

[0068] 1-Sample stage; 2-Transfer membrane; 3-Transfer head; 31-Pressing part; 32-Transfer part; 33-Bump structure; 34-Pressure dispersion part; 331-Modible bump structure; 3311-Accommodation hole; 3312-Magnetic material; 3313-Elastic membrane; 4-Chip carrier; 41-Circuit board; 5-Clamp; 6-Chip. Detailed Implementation

[0069] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0070] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0071] In traditional methods of transferring RGB LED chips, selective transfer is difficult to achieve.

[0072] Therefore, this application aims to provide a solution that can solve the above-mentioned technical problems, the details of which will be described in subsequent embodiments.

[0073] Example:

[0074] This embodiment provides a chip transfer device; please refer to [link / reference]. Figure 1 The chip transfer device includes a sample stage 1, a transfer film 2, and a transfer head 3. The sample stage 1 is used to place a chip carrier 4. The transfer film 2 is disposed on one side of the sample stage 1, and the side of the transfer film 2 closest to the sample stage 1 includes an adhesive layer for adhering the chip. The transfer film 2 is deformable under external force to contact the chip carrier 4 and returns to its shape after the external force is removed. The transfer head 3 is positioned directly opposite the sample stage 1 and includes a first displacement module for controlling the movement of the transfer head 3 towards or away from the sample stage 1. The transfer head 3 applies external force to at least a portion of the transfer film 2 to deform at least a portion of the transfer film 2 towards the sample stage 1.

[0075] The sample stage has a smooth surface, allowing the chip carrier to be placed stably on it. In actual production, the chip transfer device of this embodiment can be placed on a similarly flat workbench to ensure the yield of chip transfer.

[0076] The chip carrier can be any carrier on which a chip is already mounted during the transfer process or on which a chip needs to be mounted using a chip transfer device. This includes, but is not limited to, transient substrates on which chips are temporarily fixed, or circuit boards on which driving circuitry is arranged and can drive the chip after it has been mounted. The chips in this embodiment include, but are not limited to, LED chips or other chips that need to be transferred. For example, LED chips may include Micro-LED (Microlight-emitting diode) chips, Mini-LED (Mini light-emitting diode) chips, etc.

[0077] It is understandable that if the chip carrier is a transient substrate with a chip, when the transient substrate is placed on the sample stage, the transient substrate is located between the sample stage and the transfer film. The side of the transient substrate without the chip is in contact with the sample stage, while the chip is on the side closer to the transfer film.

[0078] The transfer film can be any elastic film material. Depending on the actual transfer requirements, the transfer film can recover its original shape after at least one or more deformations. For example, the transfer film may include a release film with an adhesive layer disposed on its surface. The adhesive layer can be bonded to the release film by methods including but not limited to coating. The adhesive strength of the adhesive layer should be greater than the bonding strength between the chip and the chip carrier (in some examples, where the chip and chip carrier are fixed with a detachable adhesive, this strength should be greater than the bonding strength after the adhesive is removed), or simultaneously greater than the weight of the chip. As an example, the adhesive layer includes PDMS (polydimethylsiloxane) adhesive. It is understood that the adhesive strength of the adhesive layer at least ensures that the chip can be stably fixed to the transfer film. In practical applications, the shape and size of the transfer film can be set according to actual needs. However, in some examples, the overall area of ​​the transfer film is larger than the area of ​​the chip carrier, which is more conducive to control and can ensure the scale and number of chips transferred in a single transfer, thus reducing the number of transfers and ensuring yield.

[0079] The specific shape and size of the transfer head are not limited, but in one example, the size of the transfer head matches the sample stage; that is, the sample stage can hold a chip carrier, and the area transferred by the transfer head in a single operation can completely cover the chip carrier. Please refer to [link to relevant documentation]. Figure 2An example is a transfer head structure comprising a pressing part 31 and a transfer part 32. The pressing part 31 may be cylindrical, with its length direction along the direction approaching or away from the sample stage 1. The pressing part 31 is connected to a first displacement module (not shown in the figure) and can extend or retract under the control of the first displacement module, that is, the pressing part 31 can move under the control of the first displacement module. The transfer part 32 is also cylindrical and is located at the end of the pressing part 31 near the sample stage 1. The end face area of ​​the transfer part 32 is larger than that of the pressing part 31. The transfer part 32 can approach the transfer membrane 2 under the drive of the pressing part 31. The transfer part 32 is used to contact the transfer membrane 2 and apply pressure to at least a portion of the transfer membrane 2.

[0080] The chip transfer apparatus of this embodiment achieves selective chip pickup and selective transfer by applying external force to at least a portion of the transfer film and utilizing the transfer film to adhere the chip. As an example of applying external force to a portion of the transfer film, the transfer head may be provided with a bump structure, such as... Figure 3 The bump structures 33 can be arranged in an array, and each bump structure 33 can be designed to correspond one-to-one with the chip position, meaning that the size and spacing of each bump structure 33 match the chip. In this example, "matching" is not limited to complete uniformity; for example, the size of the bump structure can be slightly larger or slightly smaller than the chip. In some examples, the end face size of the bump structure is 1 to 1.2 times the chip size; or slightly smaller than the chip, greater than or equal to 0.8 times the chip size. The spacing between the bump structures can be the same as the chip spacing. It can be understood that when the spacing between the bump structures is completely consistent with the chip spacing, each chip covered by the transfer head corresponds to one bump structure. When the spacing between the bump structures is inconsistent with the chip spacing, only some chips correspond to the bump structures; for example, one chip every two chips corresponds to a bump structure position, i.e., selective picking or transfer. During the transfer process, the bump structures can exert pressure on the transfer film, while areas without bump structures will not exert pressure on the transfer film, thus enabling the application of external force to certain areas of the transfer film. This deformed area of ​​the transfer film can come into contact with the chip on the chip carrier, or enable the chip fixed on the transfer film to come into contact with the chip carrier.

[0081] In some implementations, the transfer head is detachable and replaceable, thus enabling the transfer of chips of different sizes by replacing the transfer head with one of different specifications. For example, when the transfer head includes a pressing part and a transfer part, the pressing part and the transfer part can be detachably connected. When transferring chips of different specifications, only the transfer part can be replaced. The bump structure on the replaced transfer part is different from the spacing or size of the bump structure on the original transfer part.

[0082] In another example, see Figure 4 The transfer head may include a pressing section 31, a pressure dispersing section 34, and a transfer section 32. The pressing section 31 and the transfer section 32 are consistent with the previous example, while the pressure dispersing section 34 is disposed between the pressing section 31 and the transfer section 32, and its end face size is the same as that of the transfer section 32. The pressure dispersing section 34 acts as a pressure transmission device, uniformly transmitting the pressure from the pressing section 31 to the transfer section 32. In this example, if the transfer head needs adjustment, only the transfer section 32 needs to be replaced.

[0083] In some embodiments, the area where the transfer head applies external force to the transfer membrane can be varied. In one example, the transfer head further includes a second displacement module for controlling the movement of the transfer head in a plane parallel to the sample stage. That is, the transfer head can achieve planar displacement, allowing the protrusions on the transfer head to be aligned with different areas on the transfer membrane by moving the position of the transfer head. It should be noted that the second displacement module and the first displacement module can be independent of each other or combined into a single device.

[0084] In some implementations, see also Figure 5 The transfer head is provided with multiple movable bump structures 331, and each movable bump structure 331 can be in a first state (e.g. Figure 5 The movable bump structure indicated by the middle arrow a) and the second state (e.g. Figure 5 The movable bump structure 331 (indicated by arrow b) can be switched between two states. In the first state, the end face of the movable bump structure 331 is farther from the surface of the transfer head than in the second state. That is, when the transfer head is facing the sample stage, the movable bump structure 331 in the first state is closer to the sample stage. The movable bump structure 331 in the first state applies external force to a portion of the transfer film, causing this portion of the transfer film (i.e., the area corresponding to the movable bump structure 331 in the first state) to deform in a direction closer to the sample stage. As in the aforementioned example, the transfer head may include a pressing portion and a transfer portion, or in some examples, a pressure dispersing portion, with the movable bump structure 331 disposed therein in the transfer portion.

[0085] In one example, each movable bump structure can switch independently between a first state and a second state, or a portion of them can switch independently of the others between the first and second states. In these examples, the region where the transfer head applies external force to the transfer membrane can be changed by altering the state of the movable bump structures.

[0086] In another example, all the movable bump structures on the transfer head can also achieve simultaneous state switching. The transfer head can apply external force to the area of ​​the transfer film according to the movable bump structures, or the movable bump structures can be set flush with the surface of the transfer head, applying external force to the area of ​​the transfer film with the entire surface of the transfer head. However, it should be noted that the movable bump structures in the second state are not limited to being flush with the surface of the transfer head; they can still protrude from the surface of the transfer head.

[0087] For a concrete example of a movable bump structure, please see Figure 6 The movable bump structure includes:

[0088] A receiving hole 3311 is provided inside the transfer head;

[0089] Magnetic material 3312 is disposed within the receiving hole 3311;

[0090] An elastic membrane 3313 is disposed at the opening of the receiving hole 3311 near the sample stage, and the elastic membrane 3313 encloses the magnetic material 3312 inside the receiving hole 3311.

[0091] In this example, the magnetic material 3312 is used to move towards the sample stage under the action of an electromagnetic field, so as to drive the elastic membrane 3313 to deform towards the sample stage, thereby switching the movable bump structure to the first state (e.g., Figure 6 The movable bump structure indicated by the middle arrow a); the elastic membrane 3313 is used to restore its shape when the magnetic material 3312 is not subjected to an electromagnetic field, so that the movable bump structure switches to a second state (e.g., Figure 6 (The movable bump structure is indicated by arrow b). In this example, the magnetic material 3312 is moved by magnetic force to achieve state switching of the movable bump structure. In this example, the chip transfer device may also include an electromagnetic field generator, which generates an electromagnetic field to attract the magnetic material 3312 toward the sample stage. The electromagnetic field generator includes, but is not limited to, magnets or other devices that generate electromagnetic fields, and the electromagnetic field generator is controllable, that is, it can attract the magnetic material 3312 when needed and not attract the magnetic material 3312 when not needed (including but not limited to turning off the electromagnetic field or directly removing the electromagnetic field generator). In some examples, the area of ​​the magnetic field generated by the controllable magnetic field generator can be small, such as only covering a local area of ​​the transfer head, so that a part of the movable bump structure on the transfer head switches to the first state, thereby achieving local selective pickup or transfer; it is understood that if the range of the magnetic field can be controlled within the size of a single or single row (or single column) of movable bump structure in some examples, more flexible and precise selective pickup or transfer can be achieved.

[0092] The magnetic material in the movable bump structure may include, but is not limited to, magnetic particles. For example, in one example, superparamagnetic magnetic nanoparticles (Fe3O4 / Fe2O) with a particle size of 0.1-0.2 μm are used. The elastic membrane can be a highly elastic thin film material. As an example, the elastic membrane material can be a high-temperature resistant thermoplastic polyester elastomer (TPEE), such as polyurethane, which can still recover its shape well after multiple deformations to ensure the accuracy and stability of chip transfer. The thickness of the elastic membrane can be determined according to actual needs; in this example, it is set to 3-5 μm. In fact, the thickness of the transfer membrane in this embodiment can also be determined according to actual needs; this embodiment does not impose any restrictions on this.

[0093] In the above example, the aperture, arrangement, and spacing of the accommodating holes can be set according to requirements. When replacing the transfer head (or the transfer part on the transfer head) for chips of different specifications, select a transfer head (or the transfer part on the transfer head) with at least one different parameter in the aperture, arrangement, or spacing of the accommodating holes.

[0094] The movable bump structure is not limited to the above implementation. In other examples, thermally deformable materials (such as materials that expand when heated) or electrodeformable materials (such as electroactive polymers, quartz crystals, piezoelectric ceramics, and other materials that can shrink when energized) can be placed in the receiving hole. The shrinkage or elongation of these materials can be controlled by controlling the temperature or controlling the on and off of the power supply to achieve the switching between the first state and the second state.

[0095] In other examples, the chip transfer apparatus may also include modules that can displace the transfer film in a plane, such as by translating the transfer film or by rolling the transfer film with rollers to move the transfer film. Such modules can also change the position of the transfer film relative to the transfer head, thereby changing the area where the transfer head applies external force to the transfer film.

[0096] As can be seen, the chip transfer device of this embodiment can change the area where the transfer head applies external force to the transfer film through structures including but not limited to the displacement module and movable bump structure that can form various patterns, and can also change by replacing the transfer head.

[0097] In some embodiments, the sample stage includes a third displacement module for controlling the movement of the sample stage in a plane parallel to the transfer film. While in some embodiments the transfer head can move in a plane via a second displacement module, thereby enabling alignment or position changes between the transfer head and the chip on the chip carrier, enabling the sample stage to also move ensures more accurate alignment and allows for precise adjustment of the relative position between the chip carrier and the transfer film, thus adapting to a wider range of transfer scenarios.

[0098] It should also be noted that, as mentioned above, during the chip transfer process, the transfer head needs to be accurately aligned with the chip to ensure that the area of ​​the transfer film pressed by the transfer head can better contact the chip to be transferred. Furthermore, in some examples, it is also necessary to adjust the relative position between the chip carrier and the transfer film to ensure that the chip on the chip carrier (e.g., a transient substrate) can be accurately transferred to the transfer film, or that the chip on the transfer film can be accurately transferred to the target carrier (e.g., a circuit board). Alignment can be achieved using devices including, but not limited to, a CCD (Charge-coupled Device) microscope (an image sensor), or further combined with CCD visual positioning techniques to ensure transfer accuracy. Therefore, the chip transfer device may also include positioning equipment, such as the aforementioned CCD microscope.

[0099] To better facilitate chip transfer with the transfer head, in some embodiments, the chip transfer device also includes a clamp and a fourth displacement module.

[0100] The fourth displacement module is used to control the movement of the fixture toward or away from the sample stage;

[0101] The clamp is located outside the sample stage and is connected to the fourth displacement module. The clamp is used to fix the transfer membrane.

[0102] like Figure 7 The clamps 5 can include two, respectively positioned on opposite sides of the sample stage. The fourth displacement module (not shown in the figure) also includes two parts, each controlling the movement of the two clamps 5. However, the transfer membrane is generally arranged parallel to the surface of the sample stage, so the two parts of the fourth displacement module are usually controlled to move synchronously, and the distances they move are usually the same. In other examples, the clamp 5 can also be a ring structure surrounding the sample stage, or multiple clamps 5 can surround the sample stage, as long as the transfer membrane it holds and fixes is flat between the sample stage and the transfer head.

[0103] The fourth displacement module moves the fixture, thereby changing the distance between the transfer film and the chip substrate. It adjusts this distance to a suitable range and, during the transfer process, coordinates the rising and falling of the transfer film at different stages, facilitating smooth chip transfer and improving yield. For example, when transferring a chip, the fourth displacement module controls the fixture to move the transfer film closer to the sample stage. This allows the transfer film to undergo only minor deformation to pick up or place the chip onto the circuit board for transfer, keeping the deformation within a small range, reducing the requirements for the transfer film material, and further improving yield. Conversely, when placing the chip substrate on the sample stage, the fourth displacement module controls the fixture to move the transfer film away from the stage, freeing up more space for chip substrate placement. Furthermore, under the control of the fourth displacement module, it can effectively adapt to chip substrates of different thicknesses, ensuring high success and yield rates for chip transfer.

[0104] After the chip is transferred to the transfer film, a circuit board can be placed on the sample stage to receive the chip, that is, to transfer the chip from the transfer film to the circuit board. In some embodiments, bonding can be performed after the chip is placed on the circuit board. To achieve bonding quickly, the sample stage in this embodiment may include a heating device to heat the sample stage and melt the solder on the target substrate placed on the sample stage. The target substrate is the circuit board to be transferred; that is, the heating effect of the heating device is sufficient to melt the solder on the circuit board. The heating device can be located inside or under the main body of the sample stage, as long as its heat can be conducted to the circuit board. During the chip transfer process using the heating device, the transfer head can be made of a high-temperature resistant material, such as high-temperature resistant and transparent PES (polyethersulfone). The transfer film can be selected as a single-use film, and its heat resistance only needs to ensure that it is not affected by the heating device before the chip is placed on the circuit board; and in some embodiments, the chip can be placed on the circuit board first and then heated, in which case the transfer film can be a heat-insensitive transfer film.

[0105] It should be noted that the chip transfer apparatus of this embodiment is not limited to the process of transferring chips to a target substrate. Since the chip transfer apparatus can selectively pick up and transfer chips using a corresponding transfer head or by changing the state of the movable bump structure in the transfer head, and in these processes, the remaining chips do not contact the transfer film. Therefore, in some examples, the chip transfer apparatus can also be applied to the repair process after chip transfer. In practical applications, chip repair can also be considered a selective chip transfer process, but selective chip transfer has higher and more flexible requirements. As a more specific example, the chip carrier placed on the sample stage can be a circuit board with chips already bonded. If there are damaged chips on the circuit board, the chips are debonded from the circuit board by means including but not limited to lasers, and the damaged chips are removed. Using the chip transfer apparatus described in this embodiment, corresponding to the area on the circuit board where chips are missing (including the area where damaged chips have been removed, and areas where chips were not successfully transferred or where chips subsequently detached), chips are selectively picked up from the chip carrier and transferred to the missing area on the circuit board to complete the repair. During the repair process, the transfer film is less likely to come into contact with other chips already on the circuit board, reducing the impact on the existing chips on the circuit board during repair. In some embodiments, multiple different chips on the circuit board can be transferred and repaired at one time, that is, in some repair processes, only one bonding is required for the chip to be repaired.

[0106] The chip transfer apparatus of this embodiment can transfer chips from a transient substrate to a transfer film via a transfer head, and then transfer the chips to a circuit board via the transfer film. In some chip transfer processes, the transfer head can make a portion of the transfer film contact the chip carrier and pick up the chip, enabling selective chip transfer through the transfer head and transfer film. Furthermore, in some implementations, by changing the area where the transfer head applies external force to the transfer film, other chips can be transferred to different areas of the transfer film without affecting the existing chips on the film. During subsequent transfer to the circuit board, multiple chips can be transferred simultaneously, and these chips can be bonded to the circuit board in one go, avoiding the need for separate bonding of multiple chips. Therefore, the chip transfer apparatus of this embodiment can, in some implementations, reduce the number of bonding operations, reduce the complexity of the transfer process, thus reducing chip damage during bonding, improving chip transfer yield, and facilitating transfer repair.

[0107] Another optional embodiment of the present invention:

[0108] This embodiment provides a chip transfer method, which is based on the chip transfer apparatus described in the above embodiment. Please refer to [link to previous document]. Figure 8 ,include:

[0109] S101, Provides a chip transfer device;

[0110] The chip transfer device is the chip transfer device exemplified in the above embodiments.

[0111] To better understand the chip transfer method of this embodiment, a specific example is provided for further explanation. In one example, see [link to example]. Figure 9 The chip transfer apparatus provided in this example includes a sample stage 1; clamps 5 and a fourth displacement module (not shown in the figure) disposed on opposite sides of the sample stage 1; a transfer film 2 fixed on the clamps 5; and a transfer head 3 disposed opposite the sample stage 1. The transfer head 3 includes a pressing part, a pressure dispersing part, and a transfer part. The transfer head 3 includes the features described in the above embodiment and... Figure 6 The illustrated movable bump structure, in this example, is flush with the surface of the transfer head 3 in its second state; and includes an electromagnetic field generator. In this example chip transfer device, the transfer head 3 includes a first displacement module and a second displacement module, and the sample stage 1 includes a third displacement module. When the chip transfer device is in operation, it is placed on a flat worktable, with one pole of the electromagnetic field generator resting on the worktable. The sample stage 1 and the fixture 5 are located on this pole of the electromagnetic field generator, while the other pole of the electromagnetic field generator is located in a direction away from the sample stage 1 from the transfer head 3.

[0112] S102. Place the chip carrier board containing the first group of chips to be transferred on the sample stage.

[0113] The chip carrier includes, but is not limited to, a transient substrate on which a chip is temporarily placed, and its material and specifications are not restricted.

[0114] In this example, the first group of chips to be transferred can be LED chips of one color, such as any one of red, green, and blue, and the first group of chips to be transferred can be a portion of the chips on the chip carrier. That is, the chip transfer can be selective. The method of selective transfer using the chip transfer device of the present invention has been illustrated in the foregoing embodiments and will not be repeated in this embodiment.

[0115] S103. The first displacement module controls the transfer head to apply external force to the first region of the transfer film and transfers the first group of chips to be transferred onto the first region of the transfer film.

[0116] In fact, in order to ensure that the first set of chips to be transferred can be accurately transferred to the first region, after the chip carrier is placed on the sample stage, the step of adjusting the position of the chip carrier can also be included, that is, aligning the chip carrier and the transfer head. This can be achieved by controlling the sample stage to move or controlling the transfer head to move at least one of the following methods:

[0117] It should be noted that the first region is not limited to a single independent region; it may include multiple discrete small regions, each of which may correspond to one or more chips.

[0118] In some examples, the first displacement module controls the transfer head to move closer to the sample stage. During this process, the transfer head contacts the transfer film and continues to move closer to the sample stage after contact. Specifically, the transfer head contacts a first region of the transfer film, which deforms towards the sample stage due to the external force of the transfer head until the transfer film contacts the chip. The first set of chips to be transferred contacts the first region of the transfer film and is bonded to the transfer film through the adhesive layer on the transfer film.

[0119] In one example, the adhesive layer on the transfer film has stronger adhesion than the chip to the chip carrier. The transfer head moves away from the sample stage, and the transfer film gradually recovers its shape under the action of elasticity, which can directly carry the chip away from the chip carrier, realizing the step of transferring the chip to the transfer film.

[0120] In another example, the chip adheres strongly to the chip carrier. Before the transfer film carries the chip away from the chip carrier, predetermined conditions are used to reduce the adhesion between the chip and the chip carrier until the chip can be transferred onto the transfer film. For example, the chip and the chip carrier are bonded together with a de-adhesive adhesive. Depending on the properties of the adhesive, its adhesion is reduced or eliminated by means of heating, light, etc., so that the chip can be transferred to the transfer film.

[0121] like Figure 10 The image shows a specific example of a transfer process. Step S103 in the example specifically includes:

[0122] S1031, The first displacement module controls the transfer head to move towards the sample stage;

[0123] See Figure 11 and Figure 12 The first displacement module controls the transfer head 3 to move closer to the sample stage. Simultaneously, the electromagnetic field generated by the electromagnetic generator causes the movable bump structure corresponding to the first region to change to the first state, that is, the magnetic material moves under the action of the electromagnetic field, causing the elastic membrane to form a protrusion. The movable bump structure in the first state presses down on the first region of the transfer film 2, so that the first region of the transfer film 2 contacts the chip 6.

[0124] S1032. The chip is transferred to the transfer film, and the first displacement module controls the transfer head to move away from the sample stage.

[0125] like Figure 13The chip 6 is adhered to the adhesive layer of the transfer film 2. The first displacement module controls the transfer head 3 to move away from the sample stage, and the transfer film 2 gradually restores its shape. The chip 6 detaches from the chip carrier and is transferred onto the transfer film 2. As in the example above, the process of transferring the chip 6 to the transfer film 2 can be achieved by the first displacement module controlling the transfer head 3 to move away from the sample stage. In some examples, it may also be necessary to combine the steps of unadhere between the chip 6 and the chip carrier.

[0126] During this process, the electromagnetic generator shuts off the electromagnetic field or is removed, causing the movable bump structure corresponding to the first region to change to the second state, such as... Figure 14 As shown, the transfer film recovers its shape, and the first group of chips to be transferred maintains the arrangement at the time of pickup on the transfer film.

[0127] In this example, the arrangement of the movable bump structures on the transfer head corresponds to the chips and is identical to the chip arrangement specifications. In this example, there is at least a space between every two adjacent chips that can accommodate two chips (this space can correspond to the other two colors of LED chips in the RBG LED chip), and each movable bump structure corresponds to one chip.

[0128] But in another example, see Figure 15 The chips 6 are arranged relatively closely on the chip carrier 4, such as a transient substrate, but the movable bump structure is set every two chips 6. When transferring the chips 6, the same effect as the above example can be achieved. That is, there is at least a region that can accommodate two chips 6 between the same type of chips 6 finally arranged on the transfer film 2.

[0129] In another example, where the magnetic field generator can be precisely controlled to produce the electromagnetic field in a specific region, see [reference needed]. Figure 16 Chips 6 are arranged relatively closely on a chip carrier 4, such as a transient substrate. The movable bump structure has the same specifications as the arrangement of chips 6, that is, each chip 6 corresponds to one movable bump structure. By controlling the range of the electromagnetic field, only a portion of the movable bump structures can be switched to the first state, thus achieving selective transfer between two chips 6.

[0130] S104. Replace the chip carrier board placed on the sample stage with the target carrier board used to receive the chip.

[0131] As shown in the foregoing embodiments, if the transfer membrane can be moved by the fourth displacement module, before steps S102 and S104 are executed, step S1041 may be included to make steps S102 and S104 easier to operate.

[0132] S1041. Control the fourth displacement module to move the transfer membrane away from the sample stage to the target position.

[0133] Correspondingly, before step S103 and the following step S105 are executed, the following step S1042 may also be included.

[0134] S1042. Control the fourth displacement module to move the transfer membrane away from the sample stage to the target position.

[0135] It is understandable that the target positions in steps S1041 and S1042 are different, and the target positions may also change each time the above steps are executed, depending on the actual needs.

[0136] In this example, the target carrier is a circuit board, which includes a die-bonding region for bonding the chip. After the chip is transferred to the circuit board, it can be bonded to the circuit board. The circuit board may also include a driving module, which is used to connect to the chip bonded on the circuit board and drive the chip. In other examples, the target carrier can be any other chip carrier capable of receiving the transferred chip, such as a temporary storage substrate or a transfer substrate, and the chip can be transferred to the circuit board again through these chip carriers after being transferred to them.

[0137] S105. Transfer the first group of chips to be transferred from the transfer film to the target substrate;

[0138] Before transferring the chip to the target substrate, the chip on the transfer film is aligned with the target substrate. The first displacement module again controls the transfer head to move closer to the sample stage. During this process, the transfer head will contact the transfer film and continue to move closer to the sample stage after contact. The transfer head will at least contact a first area of ​​the transfer film, and the first area of ​​the transfer film will deform towards the sample stage due to the external force of the transfer head until the chip on the transfer film contacts the target substrate, thus transferring the chip to the target substrate.

[0139] In one example, the adhesive layer on the transfer film can be debonded. Depending on the material of the adhesive layer, its adhesiveness can be reduced or lost through heating, light exposure, etc., allowing the chip to detach from the transfer film and remain on the target substrate under the influence of gravity. Alternatively, in another example, the chip is bonded to an adhesive layer on the target substrate. The adhesive layer on the target substrate has higher adhesion than the adhesive layer on the transfer film. Therefore, as the transfer head moves away from the sample stage, the transfer film gradually recovers its shape under elasticity, allowing the chip to detach from the transfer film and remain on the target substrate, thus achieving chip transfer.

[0140] In this example, the target substrate is a circuit board with solder pre-placed on its die-bonding area for chip bonding. After the chip contacts the target substrate, the chips arranged on the transfer film are directly bonded to the target substrate, completing the chip transfer. Figure 17The image shows a specific example of a transfer process. Step S105 in the example specifically includes:

[0141] S1051, The first displacement module controls the transfer head to move towards the sample stage;

[0142] See Figure 18 The first displacement module controls the transfer head 3 to move closer to the sample stage, so that the chip 6 on the transfer film 2 contacts the circuit board 41. During this action, the movable bump structure on the transfer head 3 does not need to be controlled, that is, the entire surface of the transfer head 3 applies pressure to the transfer film 2, and the chip 6 on the transfer film 2 can be pressed onto the circuit board 41 and transferred in one go.

[0143] S1052. Transfer the chip to the circuit board, and the first displacement module controls the transfer head to move away from the sample stage.

[0144] Of course, the circuit board in this example can be used to bond the chip, so the chip transfer may also include the step of bonding the chip.

[0145] In other examples, during S105 above, the movable bump structure on the transfer head can be switched to the first state. When other areas on the transfer film are also located on the chip, the movable bump structure can be used to press only the chip located in the first area (i.e., the first group of chips to be transferred in this example) onto the circuit board for transfer, achieving selective transfer. Alternatively, in other examples, the movable bump structure can be arbitrarily controlled to achieve various selective transfers.

[0146] The chip transfer method of this embodiment utilizes the chip transfer apparatus of the above embodiment to first transfer the chip onto a transfer film, and then transfer it from the transfer film to a target substrate. Depending on the structure of the transfer head, the chip can be transferred to any area of ​​the transfer film, enabling selective transfer. In some embodiments, even if other areas of the transfer film already have chips, the first group of chips to be transferred can be transferred onto the transfer film without affecting other chips. In some processes, selective transfer is possible, and in others, all chips on the transfer film can be transferred at once. This chip transfer method is flexible in application and, in some implementations, helps reduce the number of bonding operations and the complexity of the transfer process. Therefore, it helps reduce chip damage during bonding, improves chip transfer yield, and facilitates transfer repair.

[0147] In some implementations, see Figure 19 Before replacing the chip carrier board placed on the sample stage with the target carrier board for receiving the chip, the process also includes:

[0148] S106. Replace the chip carrier board with the first group of chips to be transferred placed on the sample stage with the chip carrier board with the second group of chips to be transferred.

[0149] In practical applications, the second group of chips to be transferred can be LED chips with colors different from those in the first group. For example, if the first group of chips to be transferred is a red LED chip, the second group of chips to be transferred can be a blue or green LED chip.

[0150] S107. The first displacement module controls the transfer head to apply external force to the second region of the transfer film, and transfers the second set of chips to be transferred onto the second region of the transfer film.

[0151] like Figure 20 In this example, the second displacement module moves the transfer head 3 in the plane to align with the second region of the transfer film 2. At the same time, the third displacement module controls the position of the sample stage, and the second set of chips to be transferred on the sample stage are also aligned with the second region of the transfer film 2.

[0152] like Figure 21 In this example, after the second group of chips to be transferred is transferred to the second region of the transfer film, it is placed on the transfer film together with the first group of chips to be transferred. It should be noted that in practical applications, the deformation distance of the transfer film is very small. As long as it is properly controlled, the first group of chips to be transferred will not be affected when the second group of chips is transferred.

[0153] S108. Replace the chip carrier board with the second group of chips to be transferred placed on the sample stage with the chip carrier board with the third group of chips to be transferred.

[0154] In practical applications, the chips to be transferred in the third group can be LED chips with colors different from those in the first and second groups.

[0155] S109. The first displacement module controls the transfer head to apply external force to the third region of the transfer film, and transfers the third set of chips to be transferred to the third region of the transfer film.

[0156] The first, second, and third regions do not overlap;

[0157] In this example, the first, second, and third regions together constitute the layout of the RGB LED chips. Each group of adjacent sections of the first, second, and third regions forms an RGB pixel area. This means that when the chips of various colors are transferred onto the transfer film, they are already arranged in the RGB pixel configuration. When it is necessary to transfer these chips to the target substrate, the transfer of the RGB LED chips can be completed in one step on the target substrate, and these RGB LED chips are already arranged in the required RGB pixel configuration.

[0158] In some embodiments, step S105, which involves transferring the first group of chips to be transferred from the transfer film to the target substrate, may include simultaneously transferring the first group of chips to be transferred, the second group of chips to be transferred, and the third group of chips to be transferred from the transfer film to the target substrate.

[0159] In this example, as Figure 22 The first group of chips to be transferred, the second group of chips to be transferred, and the third group of chips to be transferred are placed on the circuit board 41 in one go according to the arrangement on the transfer film 2. At the same time, these chips are bonded to complete the transfer.

[0160] In some implementations, before placing the target substrate onto the sample stage, the following steps are also included:

[0161] S110. The sample stage is heated by a heating device;

[0162] In this example, the sample stage is heated before the target substrate is placed on it. After the sample stage has been heated, for example, to a predetermined temperature or for a predetermined time, the target substrate is placed on it. This allows the target substrate to be rapidly heated to a temperature that melts the solder on it, avoiding the target substrate being baked by the heat during the heating process. This reduces the time the target substrate is in a high-temperature state, thus reducing the risk of damage to the target substrate and naturally lowering the requirements for the material of the target substrate.

[0163] Of course, if the target substrate can withstand high temperatures for a certain period of time, the target substrate can be placed on the sample stage before the process of heating and melting the solder can be carried out.

[0164] By sequentially transferring three different sets of chips to different areas of the transfer film, the three sets of chips can be pre-arranged on the transfer film and transferred to the target substrate in one go, reducing the number of transfers to the target substrate. When the target substrate is a circuit board, the number of bonding operations can also be reduced, and the process complexity of the transfer can be reduced. Therefore, it is beneficial to reduce chip damage during the bonding process, improve the yield of chip transfer, and also facilitate transfer repair.

[0165] This embodiment also provides a display panel, which includes a circuit substrate and a chip, wherein the chip is transferred to the die-bonding region of the circuit substrate and bonded using the chip transfer method exemplified above in this embodiment. In some embodiments, the circuit substrate includes a driving module connected to the chip for driving the chip.

[0166] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A chip transfer device, characterized in that, include: Sample stage, used to place chip carrier boards; A transfer film is disposed on one side of the sample stage. The side of the transfer film closest to the sample stage includes an adhesive layer for adhering the chip. The transfer film is deformable under external force to contact the chip substrate and returns to its shape after the external force is removed. A transfer head is disposed directly opposite the sample stage. The transfer head includes a first displacement module, which controls the transfer head to move toward or away from the sample stage. The transfer head applies an external force to at least a portion of the transfer membrane to deform the at least a portion of the transfer membrane toward the sample stage.

2. The chip transfer apparatus as described in claim 1, characterized in that, The transfer head also includes a second displacement module, which is used to control the transfer head to move in a plane parallel to the sample stage.

3. The chip transfer apparatus as described in claim 1, characterized in that, The sample stage includes a heating device for heating the sample stage to melt the solder on the target substrate placed on the sample stage. The target substrate is a circuit board for receiving the transferred chip.

4. The chip transfer apparatus as described in claim 1, characterized in that, The sample stage includes a third displacement module, which is used to control the sample stage to move in a plane parallel to the transfer membrane.

5. The chip transfer apparatus as described in claim 1, characterized in that, It also includes a clamp and a fourth displacement module; The fourth displacement module is used to control the clamp to move towards or away from the sample stage; The clamp is located outside the sample stage and is connected to the fourth displacement module. The clamp is used to fix the transfer membrane.

6. The chip transfer apparatus according to any one of claims 1-5, characterized in that, The transfer head includes multiple movable bump structures, each of which can switch between a first state and a second state; The movable bump structure is closer to the sample stage when it is in the first state than when it is in the second state; the movable bump structure in the first state is used to apply an external force to a portion of the transfer film to deform the portion of the transfer film toward the sample stage.

7. The chip transfer apparatus as described in claim 6, characterized in that, The movable bump structure includes: A receiving hole is provided inside the transfer head; A magnetic material is disposed within the accommodating hole; An elastic membrane is disposed at the opening of the receiving hole near the sample stage, and the elastic membrane encloses the magnetic material inside the receiving hole; The magnetic material is used to move towards the sample stage under the action of an electromagnetic field, so as to cause the elastic membrane to deform and switch the movable bump structure to the first state; the elastic membrane restores its shape when the magnetic material is not subjected to an electromagnetic field, so as to switch the movable bump structure to the second state.

8. A chip transfer method, characterized in that, include: Provide a chip transfer apparatus according to any one of claims 1-7; The chip carrier board containing the first set of chips to be transferred is placed on the sample stage; The first displacement module controls the transfer head to apply external force to the first region of the transfer film, and transfers the first group of chips to be transferred to the first region of the transfer film. Replace the chip carrier placed on the sample stage with the target carrier; The first group of chips to be transferred is transferred from the transfer film to the target substrate.

9. The chip transfer method as described in claim 8, characterized in that, Before replacing the chip carrier placed on the sample stage with the target carrier, the process also includes: Replace the chip carrier board with the first set of chips to be transferred placed on the sample stage with a chip carrier board with the second set of chips to be transferred. The transfer head applies an external force to the second region of the transfer film and transfers the second set of chips to be transferred onto the second region of the transfer film; Replace the chip carrier board with the second set of chips to be transferred placed on the sample stage with a chip carrier board with the third set of chips to be transferred. The transfer head applies an external force to the third region of the transfer film and transfers the third set of chips to be transferred onto the third region of the transfer film; The first region, the second region, and the third region do not overlap.

10. A display panel, characterized in that, It includes a circuit substrate and a chip; the chip is transferred to the die-bonding region of the circuit substrate and bonded by the chip transfer method according to any one of claims 8-9.

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