Mass transfer device and transfer control method thereof

Abstract

The present invention discloses a mass transfer device and a transfer control method thereof, which relates to the field of transfer technology. The mass transfer device includes a base, a main controller, a moving mechanism, an electrostatic transfer head, a source substrate and a target substrate; the main controller and the moving mechanism are arranged on the base, and the moving mechanism is electrically connected to the main controller; the electrostatic transfer head is arranged at the end of the moving mechanism; the electrostatic transfer head is provided with a plurality of electrode bosses electrically connected to the main controller; the source substrate is arranged on the base and electrically connected to the main controller; the source substrate has a plurality of placement positions, each placement position is used to place a Micro LED chip to be transferred; the target substrate is arranged on the base and electrically connected to the main controller; the target substrate has a plurality of transfer positions, the transfer position is used to place the transferred Micro LED chip, and each transfer position is provided with a sensor electrically connected to the main controller, and the sensor is used to detect the lighting status of the Micro LED chip on the transfer position. The technical solution provided by the present invention realizes mass selective transfer while improving the transfer accuracy.

Description

Technical Field

[0001] The present invention relates to the field of transfer technology, and in particular to a mass transfer device and a transfer control method thereof. Background Art

[0002] Micro LED chips (Micro Light Emitting Diode) are an emerging display technology. Their direct production on large-size glass or other substrates is limited by current technology. Therefore, the industry generally adopts the method of producing them on semiconductor substrates and then transferring them to the driver backplane. Traditional LED substrates are mostly sapphire. However, the difference in lattice and thermal expansion coefficient between sapphire and the epitaxial layer makes it easy to bend due to stress when the size increases. In addition, sapphire substrates are incompatible with existing large-scale integrated circuit chips, which makes silicon another option as an epitaxial substrate. However, regardless of the substrate, the transfer process is involved in the production of LED products.

[0003] Traditional transfer technology is inefficient and can only transfer a few devices at a time, which is far from the large number of micro-device transfers required by modern displays. Therefore, in order to promote the mass production of Micro LED chip displays, mass transfer technology must be introduced. This technology not only requires the ability to transfer a large number of devices to the driver substrate at one time, but also ensures the transfer accuracy, yield and process reliability.

[0004] In the process of mass transfer, achieving selective mass transfer is another key technology. Currently, there are two main directions of selective mass transfer technology:

[0005] 1. Transfer method based on film stretching and patterned laser: This method temporarily bonds the chip on a stretched polymer transparent film, then adjusts the film stretching degree to change the chip spacing, and finally uses a patterned laser to release the chip. However, this method has problems such as uneven spacing during stretching and high cost of patterned laser.

[0006] 2. Transfer method based on transfer stamp: Using a transfer stamp with a microstructure, the chip can be patterned and selectively picked up and released onto the circuit substrate. However, this method requires complex stamp production and the transfer accuracy needs to be improved.

[0007] Therefore, the existing selective mass transfer technology has the problems of high cost and low transfer accuracy. Summary of the invention

[0008] The main purpose of the present invention is to provide a mass transfer device and a transfer control method thereof, aiming to reduce the cost of mass selective transfer while improving the transfer accuracy.

[0009] To achieve the above-mentioned purpose, the present invention proposes a mass transfer device, which comprises:

[0010] Base;

[0011] A main controller, the main controller is arranged on the base;

[0012] A moving mechanism, the moving mechanism is arranged on the base and is electrically connected to the main controller;

[0013] An electrostatic transfer head, the electrostatic transfer head is arranged at the end of the moving mechanism; the electrostatic transfer head is provided with a plurality of electrode bosses electrically connected to the main controller, and the plurality of electrode bosses are arranged in an array;

[0014] A source substrate, the source substrate is disposed on the base and electrically connected to the main controller; the source substrate has a plurality of placement positions arranged in an array, each of the placement positions is used to place a Micro LED chip to be transferred;

[0015] and a target substrate, the target substrate is arranged on the base and electrically connected to the main controller; the target substrate has a plurality of transfer positions arranged in an array, the transfer positions are used to place the transferred Micro LED chips, each of the transfer positions is provided with a sensor electrically connected to the main controller, and the sensor is used to detect the lighting status of the Micro LED chip placed on the transfer position.

[0016] In one embodiment, the electrostatic transfer head comprises:

[0017] A first AC power source, which is provided in the mobile mechanism and is electrically connected to the main controller;

[0018] and a transfer head substrate, wherein the transfer head substrate is arranged on a side of the first AC power source facing away from the moving mechanism; and a plurality of electrode bosses are arranged on a side of the transfer head substrate facing away from the first AC power source and are electrically connected to the first AC power source.

[0019] In one embodiment, an insulating dielectric layer is deposited on a side of each electrode boss facing away from the transfer head substrate.

[0020] In one embodiment, the source substrate comprises:

[0021] A second AC power source, which is disposed on the base and electrically connected to the main controller;

[0022] and a substrate layer, wherein the substrate layer is arranged on a side of the second AC power source facing away from the base; the substrate layer has a plurality of placement positions, each of which is provided with a first connection circuit, and the plurality of first connection circuits are electrically connected to the second AC power source respectively; the first connection circuit is used to connect the MicroLED chip placed at the placement position to the second AC power source.

[0023] In one embodiment, the substrate layer comprises:

[0024] A transition substrate, the transition substrate being arranged on a side of the second AC power source facing away from the base;

[0025] and an adhesive layer, wherein the adhesive layer is arranged on a side of the transition substrate facing away from the second AC power source, the adhesive layer has a plurality of placement positions, and each placement position is embedded with a first connection circuit, and the adhesive layer is used to bond the Micro LED chip.

[0026] In one embodiment, the target substrate comprises:

[0027] a receiver substrate, the receiver substrate being disposed on the base;

[0028] and a plurality of conducting parts, wherein the plurality of conducting parts are all arranged on one side of the receiver substrate and are electrically connected to the main controller respectively; each of the conducting parts has one transfer position, and each of the sensors is embedded in one of the conducting parts.

[0029] In one embodiment, the target substrate further includes an insulating contact pad disposed between the receiver substrate and the plurality of vias.

[0030] In one embodiment, the sensor is a photoelectric sensor.

[0031] The present invention further provides a transfer control method for a mass transfer device, wherein the mass transfer device is the mass transfer device as described above; the steps of the transfer control method for the mass transfer device include:

[0032] Controlling the moving mechanism to drive the electrostatic transfer head to move until the plurality of electrode bosses of the electrostatic transfer head correspond one by one to the plurality of Micro LED chips to be transferred on the source substrate, and then controlling the moving mechanism to stop running;

[0033] Controlling the electrostatic transfer head to pass a positive current and the source substrate to pass a negative current, so that each of the Micro LED chips is adsorbed onto the corresponding electrode boss;

[0034] Controlling the moving mechanism to drive the electrostatic transfer head to approach the target substrate until the Micro LED chip adsorbed on the electrode boss corresponds to a placement position, and then controlling the moving mechanism to stop running;

[0035] Obtaining a feedback signal from the sensor of the target substrate, and confirming a target position where the Micro LED needs to be transferred according to the feedback signal;

[0036] According to the target position, the electrode boss corresponding to the target position is controlled to pass a negative current, so that the Micro LED located at the target position is released to a corresponding placement position on the target substrate.

[0037] In one embodiment, the step of obtaining feedback signals from a plurality of sensors of the target substrate and confirming a target position where the Micro LED needs to be transferred according to the feedback signals includes:

[0038] Controlling the target substrate to be powered on so that a portion of the Micro LED chips located on the electrostatic transfer head illuminates;

[0039] Receiving feedback signals collected by the plurality of sensors, wherein the plurality of sensors collecting the feedback signals correspond one to one with the plurality of Micro LED chips located on the electrostatic transfer head and emitting light;

[0040] The plurality of feedback signals are analyzed to obtain a target position where the Micro LED needs to be transferred.

[0041] In one embodiment, according to the target position, before the step of controlling the electrode boss corresponding to the target position to pass a negative current so that the Micro LED located at the target position is released to the corresponding placement position on the target substrate, the step further includes:

[0042] According to the target position, the electrode boss that does not correspond to the target position is controlled to pass a positive current, so that the Micro LED that does not correspond to the target position continues to be adsorbed on the electrostatic transfer head.

[0043] The mass transfer device of the technical solution of the present invention includes a base, a main controller, a moving mechanism, an electrostatic transfer head, a source substrate and a target substrate; the main controller is arranged on the base; the moving mechanism is arranged on the base and electrically connected to the main controller; the electrostatic transfer head is arranged at the end of the moving mechanism; the electrostatic transfer head is provided with a plurality of electrode bosses electrically connected to the main controller, and the plurality of electrode bosses are arranged in an array; the source substrate is arranged on the base and electrically connected to the main controller; the source substrate has a plurality of placement positions arranged in an array, each placement position is used to place a Micro LED chip to be transferred; the target substrate is arranged on the base and electrically connected to the main controller; the target substrate has a plurality of transfer positions arranged in an array, the transfer position is used to place the transferred Micro LED chip, each transfer position is provided with a sensor electrically connected to the main controller, and the sensor is used to detect the lighting status of the Micro LED chip placed on the transfer position; in this way, by setting the electrostatic transfer head and applying currents of different polarities to the electrostatic transfer head and the source substrate, a mass transfer of a plurality of Micro LED chips is achieved; then, a plurality of transfer positions provided with sensors correspond one by one to a plurality of Micro LED chips adsorbed on the electrostatic transfer head, and the sensors are used to detect whether the Micro LED chips are lit. The electrical signal from the LED chip is used to determine whether the Micro LED chip is the workpiece to be transferred, reducing the cost of mass selective transfer. And because multiple sensors can only perform detection work when they correspond to multiple Micro LED chips one by one, the position of the Micro LED chip that needs to be transferred can be accurately confirmed, thereby improving the transfer accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0045] Figure 1 A schematic diagram of the structure of an electrostatic transfer head and a source substrate of a mass transfer device provided by the present invention;

[0046] Figure 2 A schematic structural diagram of a target substrate of a mass transfer device provided by the present invention;

[0047] Figure 3 A schematic diagram of the structure of the electrostatic transfer head and the source substrate of the mass transfer device provided by the present invention in the pre-pickup stage;

[0048] Figure 4 A schematic structural diagram of an electrostatic transfer head and a source substrate of a mass transfer device provided by the present invention in the picking-up stage;

[0049] Figure 5 A schematic diagram of the structure of the electrostatic transfer head and the source substrate of the mass transfer device provided by the present invention in the post-pickup stage;

[0050] Figure 6 A schematic diagram of the structure of the electrostatic transfer head and the target substrate of the mass transfer device provided by the present invention in the pre-release stage;

[0051] Figure 7 A schematic diagram of the structure of the electrostatic transfer head and the target substrate of the mass transfer device provided by the present invention in the release stage;

[0052] Figure 8 A schematic diagram of the structure of the electrostatic transfer head and the target substrate of the mass transfer device provided by the present invention in the post-release stage;

[0053] Fig. 9 A schematic diagram of the structure of a mass transfer device provided by the present invention;

[0054] Fig.10 A schematic flow chart of a transfer control method for a mass transfer device provided by the present invention;

[0055] Fig.11 This is a flow chart of detailed steps of S40 of the transfer control method of the mass transfer device provided by the present invention.

[0056] Description of Figure Numbers:

[0057] 10. Main controller; 20. Electrostatic transfer head; 20a. Electrode boss; 21. First AC power supply; 22. Transfer head substrate; 23. Insulating dielectric layer; 30. Source substrate; 30a. Placement position; 31. Second AC power supply; 32. Substrate layer; 321. Transition substrate; 322. Adhesive layer; 1. Micro LED chip; 40. Target substrate; 41. Receiver substrate; 42. Conductive part; 43. Insulating contact pad; 2. Feedback signal.

[0058] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0059] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0061] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0062] The present invention provides a mass transfer device.

[0063] See also Figures 1 to 8 In one embodiment of the present invention, the mass transfer device includes a base, a main controller 10, a moving mechanism, an electrostatic transfer head 20, a source substrate 30 and a target substrate 40; the main controller 10 is arranged on the base; the moving mechanism is arranged on the base and electrically connected to the main controller 10; the electrostatic transfer head 20 is arranged at the end of the moving mechanism; the electrostatic transfer head 20 is provided with a plurality of electrode bosses 20a electrically connected to the main controller 10, and the plurality of electrode bosses 20a are arranged in an array; the source substrate 30 is arranged on the base and electrically connected to the main controller 10; the source substrate 30 has a plurality of placement positions 30a arranged in an array, each placement position 30a is used to place a Micro LED chip to be transferred; the target substrate 40 is arranged on the base and electrically connected to the main controller 10; the target substrate 40 has a plurality of transfer positions arranged in an array, the transfer position is used to place the transferred Micro LED chip, and each transfer position is provided with a sensor electrically connected to the main controller 10, and the sensor is used to detect the lighting status of the Micro LED chip placed on the transfer position.

[0064] Each placement position 30a of the source substrate 30 is placed with a Micro LED chip to be transferred. At this time, the staff starts the mass transfer device to transfer the multiple Micro LED chips on the source substrate 30 to the corresponding transfer positions on the target substrate 40. The main controller 10 controls the electrostatic transfer head 20 to pass a positive current and controls the source substrate 30 to pass a negative current. The electrostatic transfer head 20 generates positive charges under the positive current, and the source substrate 30 generates negative charges under the negative current; then the moving mechanism is controlled to drive the electrostatic transfer head 20 to move to face the source substrate 30, that is, when the multiple electrode bosses 20a of the electrostatic transfer head 20 face the multiple Micro LED chips on the source substrate 30 one by one, the positive charges and negative charges will interact with each other and generate electrostatic attraction, so that the multiple Micro LED chips on the source substrate 30 are adsorbed onto the corresponding multiple electrode bosses 20a, completing the overall pickup of the multiple Micro LED chips.

[0065] Then, the main controller 10 controls the moving mechanism to drive the electrostatic transfer head 20 to move towards the target substrate 40 until the multiple Micro LED chips on the electrostatic transfer head 20 correspond one-to-one with the multiple transfer positions on the target substrate 40 and then stop moving; at this time, the multiple Micro LED chips correspond one-to-one with the sensors on the multiple transfer positions, so that the distance between the multiple Micro LED chips and the multiple sensors is within the detectable range, and the main controller 10 controls the electrostatic transfer head 20 and the target substrate 40 to be powered on respectively, and uses whether the sensor detects the electrical signal of the Micro LED chip being turned on to determine whether the multiple Micro LED chips are the Micro LED chips to be transferred; the normally turned-on Micro LED chips will be detected by the sensor, and the abnormal Micro LED chips will not be detected by the sensor. The sensor feeds back an electrical signal to the main controller 10. The main controller 10 determines the position of the Micro LED chip to be transferred according to the received feedback signal 2, and selectively controls part of the electrode bosses 20a of the electrostatic transfer head 20 to pass a negative current, so that the Micro LED chip on the electrode bosses 20a with negative current can be released to the corresponding transfer position on the target substrate 40, thereby realizing the mass selective transfer of multiple Micro LED chips. For the position of the Micro LED chip without the feedback signal 2, the main controller 10 will continue to control the electrode bosses 20a of this part to pass a positive current, so that the electrode bosses 20a of this part can continue to absorb the Micro LED chip, thereby preventing the Micro LED chip that does not need to be transferred from being released to the target substrate 40.

[0066] From the above-mentioned mass transfer process, the electrode boss 20a and the Micro LED chip can be regarded as two separate charged bodies, and electrostatic forces are generated to interact with each other. In the stage of picking up the Micro LED chip, different charges are generated on the electrode boss 20a and the Micro LED chip. The electrode boss 20a is positively charged to generate electrostatic attraction. At this time, the Micro LED chip in contact with it is adsorbed on the electrostatic transfer head 20 by the electrostatic attraction. In the stage of placing the Micro LED chip, by adjusting the voltage difference between the inner and outer electrodes of the electrode boss 20a, the electrode boss 20a is negatively charged so that the voltage difference is zero, and electrostatic repulsion is generated, so that the Micro LED chip is released from the electrostatic transfer head 20 and accurately placed on the predetermined position of the target substrate 40.

[0067] Compared with traditional transfer technology, the selective electrostatic transfer head 20 technology of the present invention is not only easy to operate, but also highly applicable. Regardless of the size or shape of MicroLED, this technology can achieve efficient mass transfer. At the same time, due to the use of the principle of electrostatic force, this technology also has extremely high positioning accuracy, which can meet the extremely high requirements for transfer accuracy in the field of MicroLED display. Therefore, the selective electrostatic transfer head 20 technology of the present invention provides a new solution for the patterning and selective mass transfer of MicroLED, which has broad application prospects and market potential.

[0068] In this embodiment, an electrostatic transfer head 20 is provided, and currents of different polarities are applied to the electrostatic transfer head 20 and the source substrate 30 to achieve mass transfer of multiple Micro LED chips. Subsequently, multiple transfer positions equipped with sensors are matched one-to-one with the multiple Micro LED chips adsorbed on the electrostatic transfer head 20, and whether the Micro LED chip is a workpiece to be transferred is determined by whether the sensor detects an electrical signal of the Micro LED chip being turned on, thereby avoiding the use of the surface pattern of the workpiece to select whether to transfer, thereby reducing the cost of mass selective transfer. Furthermore, since the detection work can only be performed when multiple sensors correspond one-to-one with multiple Micro LED chips, the position of the Micro LED chip to be transferred can be accurately confirmed, thereby improving the transfer accuracy.

[0069] The mass transfer device completes the overall pickup of multiple Micro LED chips through the cooperation of the main controller 10, the moving mechanism, the electrostatic transfer head 20 and the source substrate 30, thereby improving the transfer efficiency. Subsequently, the selection of the Micro LED chips to be transferred is completed through the cooperation of the main controller 10, the electrostatic transfer head 20 and the target substrate 40, and finally the multiple Micro LED chips to be transferred are released at the same time, thereby completing the mass selective transfer of multiple Micro LED chips. This design not only optimizes the transfer process and improves the transfer speed, but also effectively avoids the collision and damage of the Micro LED chips during the transfer process, thereby improving the reliability of the mass transfer device.

[0070] Again, the source substrate 30 and the target substrate 40 are both arranged on the base and electrically connected to the main controller 10. The source substrate 30 has a plurality of placement positions 30a for placing the Micro LED chips to be transferred, and the target substrate 40 has a plurality of transfer positions for placing the transferred Micro LED chips. This design makes the entire transfer process more orderly, effectively reduces the error in the transfer process, and improves the product yield.

[0071] The base is the main part of the mass transfer device, which is used to support the entire device. The base is made of high-strength metal material to ensure the stability and durability of the device. The main controller 10 includes an upper computer and a lower computer, both of which are arranged on the base. The upper computer can be an ordinary PC, which is used to receive the feedback signal 2 containing the position code of the Micro LED chip sent by the sensor, and send the corresponding control signal to the lower computer according to the position code; the lower computer is directly electrically connected to the moving mechanism, the electrostatic transfer head 20, the source substrate 30 and the target substrate 40. Under the control of the upper computer, the lower computer selects the polarity of each electrode boss 20a of the electrostatic transfer head 20 in an orderly manner, so as to selectively energize the corresponding electrode boss 20a of the electrostatic transfer head 20. The upper computer is connected to the lower computer in communication so that the control instruction converted by the upper computer according to the feedback signal 2 can be transmitted to the lower computer, and the lower computer controls the operation of the moving mechanism, the electrostatic transfer head 20, the source substrate 30 and the target substrate 40 according to the control instruction.

[0072] The moving mechanism is arranged on the base and electrically connected to the lower machine of the main controller 10. The moving mechanism includes a stepping motor and a guide rail for accurately controlling the movement of the electrostatic transfer head 20. Electrostatic transfer head 20: The electrostatic transfer head 20 is arranged at the end of the moving mechanism. The electrostatic transfer head 20 includes a plurality of electrode bosses 20a, which are arranged in an array and are used to generate static electricity, thereby transferring the Micro LED chip from the source substrate 30 to the target substrate 40. The source substrate 30 is arranged on the base and electrically connected to the main controller 10. The source substrate 30 has a plurality of placement positions 30a, each of which is used to place a Micro LED chip to be transferred. The design of the placement position 30a ensures the safe placement and accurate transfer of the chip. The target substrate 40 is arranged on the base and electrically connected to the main controller 10. The target substrate 40 has a plurality of transfer positions for placing the transferred Micro LED chip. Each transfer position is provided with a sensor for detecting the lighting condition of the Micro LED chip placed on the placement position 30a.

[0073] In one embodiment, see Figure 1 , Figure 3 , Figure 4 and Figure 5 The electrostatic transfer head 20 includes a first AC power supply 21 and a transfer head substrate 22. The first AC power supply 21 is arranged on the moving mechanism and is electrically connected to the main controller 10; the transfer head substrate 22 is arranged on the side of the first AC power supply 21 facing away from the moving mechanism; a plurality of electrode bosses 20a are arranged on the side of the transfer head substrate 22 facing away from the first AC power supply 21 and are electrically connected to the first AC power supply 21.

[0074] The first AC power source 21 is arranged on the mobile mechanism and is electrically connected to the main controller 10 through an electrical connection line, and is used to provide the AC power required for static electricity transfer. The transfer head substrate 22 is arranged on the side of the first AC power source 21 facing away from the mobile mechanism, and is used to support and fix the electrode boss 20a. A plurality of electrode bosses 20a are arranged on the side of the transfer head substrate 22 facing away from the first AC power source 21. Each electrode boss 20a is electrically connected to the first AC power source 21 to achieve the generation and transfer of static electricity.

[0075] Each electrode boss 20a has the ability to generate bipolar static electricity under the action of the first AC power supply 21. The top of the electrode boss 20a has two separated electrodes, which are led out through metal. The electrode boss 20a is made by conventional microelectronic processing, so these electrode bosses 20a can be connected by microcircuit, so that different voltage signals can be quickly applied. The transfer head substrate 22 is connected to the electrode boss 20a. The material of the transfer head substrate 22 is insulating, preferably transparent glass or plastic products, and preferably square in shape, but other shapes can also be used. The first AC power supply 21 can preferably use silicon electrodes. The electrode bosses 20a are preferably arranged in 8×8, but other arrangements can also be used.

[0076] When the main controller 10 sends a start signal, the first AC power supply 21 starts working and outputs AC power. The AC power is transmitted to the moving mechanism through the electrical connection line, causing the moving mechanism to start moving. The moving mechanism drives the electrode boss 20a to move above the Micro LED chip to be transferred. Under the action of the electrostatic field, the electrode boss 20a generates static electricity, which adsorbs the Micro LED chip to be transferred on its surface. The moving mechanism drives the electrode boss 20a and the Micro LED chip to be transferred to the target position. When the electrode boss 20a leaves the surface of the Micro LED chip to be transferred, the electrostatic field disappears, and the Micro LED chip to be transferred is released.

[0077] In this embodiment, the first AC power source 21 and the plurality of electrode bosses 20a are used to generate an electrostatic force that can absorb the Micro LED chip. This picking direction does not squeeze the surface of the Micro LED chip, thereby achieving lossless transfer of the Micro LED chip. At the same time, the structure of the first AC power source 21 and the plurality of electrode bosses 20a is simpler than the mechanical structure of the traditional clamping method, which is conducive to the miniaturization of the mass transfer device.

[0078] In one embodiment, see Figure 1 , Figure 3 , Figure 4 and Figure 5 An insulating dielectric layer 23 is deposited on the side of each electrode boss 20a facing away from the transfer head substrate 22.

[0079] The deposition of the insulating dielectric layer 23 reduces the leakage between the electrode and the substrate, ensures the stable operation of the electrostatic transfer head 20 in a complex environment, and thus improves the safety and reliability of the electrostatic transfer head 20. The insulating dielectric layer 23 used in the present invention can protect the electrode boss 20a from the erosion of the external environment to a certain extent, such as preventing moisture and dust from corroding the electrode, prolonging the service life of the electrode boss 20a, and reducing the maintenance frequency and cost of the electrostatic transfer head 20 due to its excellent insulation properties.

[0080] The electrode boss 20a is located on the top of the transfer head substrate 22. The design of the electrode boss 20a is conducive to increasing the contact area with the transfer head substrate 22 and enhancing the stability of the electrode boss 20a. An insulating dielectric layer 23 is deposited on the side of the electrode boss 20a facing away from the transfer head substrate 22. The thickness and material of the insulating dielectric layer 23 can be selected according to actual needs. Preferably, the insulating dielectric layer 23 uses aluminum oxide (Al2O3) as a material. Aluminum oxide has good insulation properties and chemical stability, and can effectively prevent short circuits between the electrode and the transfer head substrate 22.

[0081] In one embodiment, see Figure 1 , Figure 3 , Figure 4 and Figure 5 The source substrate 30 includes a second AC power supply 31 and a substrate layer 32. The second AC power supply 31 is arranged on the base and is electrically connected to the main controller 10. The substrate layer 32 is arranged on the side of the second AC power supply 31 facing away from the base. The substrate layer 32 has a plurality of placement positions 30a, and a first connection circuit is arranged at each placement position 30a, and the plurality of first connection circuits are electrically connected to the second AC power supply 31 respectively. The first connection circuit is used to connect the Micro LED chip placed at the placement position 30a to the second AC power supply 31.

[0082] The substrate layer 32 is arranged on the side of the second AC power supply 31 facing away from the base, and has a plurality of placement positions 30a. This design makes the placement of the Micro LED chip more flexible and easy to operate and maintain. The placement position 30a on the substrate layer 32 provides a fixed position for the Micro LED chip, ensuring the stability of the chip during processing and avoiding processing errors caused by chip displacement. Most importantly, a first connection circuit is arranged at each placement position 30a, and the plurality of first connection circuits are electrically connected to the second AC power supply 31 respectively. This innovative design makes the contact and conduction between the Micro LED chip and the second AC power supply 31 more direct and efficient. The existence of the first connection circuit not only simplifies the circuit connection, but also improves the response speed and signal transmission efficiency of the system.

[0083] Each Micro LED chip has the ability to generate bipolar static electricity under the action of the second AC power supply 31. The substrate material of the Micro LED chip is generally a transparent sapphire substrate. These Micro LED chips are made by conventional microelectronic processing, so these Micro LED chips can be connected by microcircuits, so that different voltage signals can be quickly applied. Multiple Micro LED chips are preferably arranged in an 8×8 manner, and other arrangements can also be used following the electrode boss 20a, ultimately forming an arrayed, tightly arranged micro light-emitting diode array, and the size of a single Micro LED chip is about 10mm to 20um.

[0084] The second AC power supply 31 is arranged on the base and connected to the main controller 10 through an electrical connection line. The main function of the second AC power supply 31 is to provide a stable AC power supply for the source substrate 30. The base provides a stable support for the source substrate 30, and its material can be selected according to actual needs, such as metal, plastic, etc. The electrical connection line is used to connect the second AC power supply 31 and the main controller 10 to ensure stable power transmission. The substrate layer 32 is arranged on the side of the second AC power supply 31 facing away from the base, and its main function is to carry the Micro LED chip. A plurality of placement positions 30a are provided on the substrate layer 32, and each placement position 30a is used to place a Micro LED chip. The number and distribution of the placement positions 30a can be designed according to actual needs. A first connection circuit is provided at each placement position 30a. The circuit is used to connect the Micro LED chip placed in the placement position 30a to the second AC power supply 31.

[0085] In one embodiment, see Figure 1 , Figure 3 , Figure 4 and Figure 5 The substrate layer 32 includes a transition substrate 321 and an adhesive layer 322. The transition substrate 321 is arranged on the side of the second AC power source 31 facing away from the base; the adhesive layer 322 is arranged on the side of the transition substrate 321 facing away from the second AC power source 31. The adhesive layer 322 has a plurality of placement positions 30a, and a first connection circuit is embedded in each placement position 30a. The adhesive layer 322 is used to bond the Micro LED chip.

[0086] The adhesive layer 322 is used to bond the Micro LED chip, and its special structural design ensures a strong bond between the chip and the substrate layer 32. Compared with the prior art, the adhesive layer 322 has significant advantages in bonding strength and stability, effectively preventing the Micro LED chip from falling off or shifting before being transferred. The design of the transition substrate 321 helps to effectively disperse heat and avoid heat accumulation at the bottom of the chip, thereby reducing the impact of thermal stress on the chip. This structure helps to improve the working stability of the Micro LED chip and extend its service life.

[0087] In this embodiment, the substrate layer 32 includes a transition substrate 321 and an adhesive layer 322. The transition substrate 321 is provided on the side of the second AC power source 31 facing away from the base, and its main function is to serve as a transition layer between the substrate and the Micro LED chip to ensure a good connection between the substrate and the Micro LED chip. The material, thickness and shape of the transition substrate 321 are selected and designed according to specific application requirements. An adhesive layer 322 is provided on the side of the transition substrate 321 facing away from the second AC power source 31. The main function of the adhesive layer 322 is to bond the Micro LED chip to ensure a stable connection between the chip and the substrate. The material of the adhesive layer 322 can be selected from silicone, polyimide, epoxy resin, etc., which have good bonding performance and thermal stability. The first connection circuit is embedded in the placement position 30a in the adhesive layer 322, and is used to connect the Micro LED chip to the transition substrate 321. The material of the first connection circuit can be selected from conductive materials such as gold and copper to ensure good electrical connection performance. The Micro LED chip is placed on the placement position 30a of the adhesive layer 322 and is connected to the transition substrate 321 through the first connection circuit. The material, size and performance of Micro LED chips are determined according to actual application requirements.

[0088] In one embodiment, see Figure 1 , Figure 2 , Figure 6 , Figure 7 and Figure 8 The target substrate 40 includes a receiver substrate 41 and a plurality of conductive portions 42 , wherein the receiver substrate 41 is disposed on a base; the plurality of conductive portions 42 are all disposed on one side of the receiver substrate 41 and are electrically connected to the main controller 10 respectively; each conductive portion 42 has a transfer position, and each sensor is embedded in a conductive portion 42 .

[0089] A plurality of conductive portions 42 are provided on one side of the receiver substrate 41. These conductive portions 42 are evenly distributed, and each conductive portion 42 is electrically connected to the main controller 10. The conductive portion 42 is used to energize and light up the Micro LED chip. The preferred material is aluminum-nickel-cobalt alloy, and other conductive materials can also be selected. The main controller 10 is responsible for receiving and processing the electrical signal sent from the sensor on the conductive portion 42, so as to accurately confirm the position of the Micro LED chip to be transferred. When the target substrate 40 is energized, the receiver substrate 41 transfers electrical energy to the conductive portion 42. The conductive portion 42 can transfer electrical energy to the sensor in the inner cavity, so that the sensor can operate; when the sensor generates a corresponding electrical signal according to the change of the Micro LED chip on the electrostatic transfer head 20, the signal is transmitted to the main controller 10 through the conductive portion 42. The main controller 10 processes the received electrical signal and outputs an instruction to control the corresponding Micro LED chip on the electrostatic transfer head 20 to energize, thereby accurately controlling the electrostatic transfer head 20 to adsorb or release the Micro LED chip.

[0090] In one embodiment, see Figure 1 , Figure 2 , Figure 6 , Figure 7 and Figure 8 The target substrate 40 further includes an insulating contact pad 43 disposed between the receiver substrate 41 and the plurality of vias 42 .

[0091] By providing an insulating contact pad 43 between the receiver substrate 41 and the plurality of conductive portions 42, the electrical signal interference between the receiver substrate 41 and the conductive portions 42 is effectively isolated, and the conductive portions 42 are prevented from directly contacting the receiver substrate 41, thereby avoiding undesirable phenomena such as short circuits. Secondly, adding the insulating contact pad 43 between the receiver substrate 41 and the conductive portions 42 can effectively alleviate the stress caused by thermal expansion or contraction, and avoid deformation of the target substrate 40 due to temperature changes. This helps to increase the service life of the product and reduce maintenance costs.

[0092] The receiver substrate 41 is preferably made of semiconductor materials such as silicon and gallium arsenide, which have good conductivity and stability. The insulating contact pad 43 is preferably made of materials with good insulation properties such as polyimide and polytetrafluoroethylene, and its thickness can be adjusted according to actual needs.

[0093] In one embodiment, the sensor is a photoelectric sensor.

[0094] The photoelectric sensor can quickly respond to changes in light signals, thereby achieving real-time monitoring and greatly improving detection efficiency. Due to the high-precision characteristics of the photoelectric sensor, the present invention can obtain data more accurately during the detection process, effectively reducing errors.

[0095] The present invention also provides a transfer control method for a mass transfer device, wherein the mass transfer device is the mass transfer device as described above; see Figures 1 to 9 and Fig.10 The steps of the transfer control method of the mass transfer device include:

[0096] S10: Controlling the moving mechanism to drive the electrostatic transfer head 20 to move until the plurality of electrode bosses 20a of the electrostatic transfer head 20 correspond one by one to the plurality of Micro LED chips to be transferred on the source substrate 30, and then controlling the moving mechanism to stop running;

[0097] First, the electrostatic transfer head 20 is moved by the moving mechanism until the multiple electrode bosses 20a of the electrostatic transfer head 20 correspond one by one with the multiple Micro LED chips to be transferred on the source substrate 30. At this time, the moving mechanism is controlled to stop running to ensure that the electrode bosses 20a are accurately aligned with the Micro LED chips. This step improves the accuracy and efficiency of the transfer, avoids damage to the Micro LED chips or transfer failures caused by position deviation, and greatly improves the transfer efficiency of the Micro LED chips.

[0098] S20: Control the electrostatic transfer head 20 to pass a positive current and the source substrate 30 to pass a negative current, so that each of the Micro LED chips is adsorbed onto the corresponding electrode boss 20a;

[0099] By controlling the electrostatic transfer head 20 to pass positive current, and controlling the source substrate 30 to pass negative current, the positive and negative currents are passed so that each Micro LED chip is adsorbed onto the corresponding electrode boss 20a. The realization of electrostatic adsorption ensures that the Micro LED chip will not fall off during the subsequent transfer process. This innovative method not only simplifies the transfer process, but also reduces production costs, while avoiding physical damage to the Micro LED chip caused by the traditional mechanical claw transfer method, and improving the reliability and stability of the Micro LED chip.

[0100] S30: Control the moving mechanism to drive the electrostatic transfer head 20 to approach the target substrate 40 until the Micro LED chip adsorbed on the electrode boss 20a corresponds to a placement position 30a, and then control the moving mechanism to stop running;

[0101] The moving mechanism is started again, driving the electrostatic transfer head 20 to approach the target substrate 40. During the moving process, the Micro LED chip adsorbed on the electrode boss 20a corresponds to the placement position 30a on the target substrate 40. At this time, the moving mechanism is controlled to stop running and prepare for the release of the Micro LED chip to ensure that multiple Micro LED chips can be accurately released to the preset positions on the target substrate 40.

[0102] S40: Acquire a feedback signal 2 of the sensor of the target substrate 40, and confirm a target position where the Micro LED needs to be transferred according to the feedback signal 2;

[0103] After step S30 is completed, the sensor on the target substrate 40 starts working and obtains feedback signals 2. These feedback signals 2 are used to confirm the target position where the Micro LED needs to be transferred, providing a basis for the subsequent release step. The present invention controls the moving mechanism to drive the electrostatic transfer head 20 close to the target substrate 40, and confirms the target position where the Micro LED needs to be transferred according to the sensor feedback signal 2 of the target substrate 40, avoiding the previous setting of different patterns for each Micro LED chip to confirm the position where the Micro LED chip needs to be transferred, while greatly reducing the production cost and the computing power cost generated in the confirmation and identification process, and also achieving precise positioning.

[0104] S50 : According to the target position, controlling the electrode boss 20 a corresponding to the target position to pass a negative current, so that the Micro LED located at the target position is released to the corresponding placement position 30 a on the target substrate 40 .

[0105] Subsequently, the electrode boss 20a corresponding to the target position is controlled to pass a negative current, so that the Micro LED chip located at the target position is released to the corresponding placement position 30a on the target substrate 40. At this point, the transfer control method of the mass transfer device completes a cycle. This step can easily realize the release of the Micro LED chip by the electrostatic transfer head 20 by changing the opposite polarity current of the electrode boss 20a corresponding to the Micro LED chip to be transferred, greatly reducing the difficulty of transferring the Micro LED chip. Since the Micro LED chip can only be released when it corresponds to the placement position 30a on the target substrate 40 one by one, the placement of the Micro LED chip on the target substrate 40 is more uniform, which is beneficial to the subsequent packaging and testing work.

[0106] The present invention realizes mass transfer of multiple Micro LED chips by setting an electrostatic transfer head 20 and applying currents of different polarities to the electrostatic transfer head 20 and the source substrate 30; then, multiple transfer positions with sensors are set to correspond one-to-one with the multiple Micro LED chips adsorbed on the electrostatic transfer head 20, and whether the Micro LED chip is a workpiece to be transferred is determined by whether the sensor detects the electrical signal of the Micro LED chip being turned on, and the position of the Micro LED chip to be transferred is accurately confirmed, thereby reducing the cost of mass selective transfer and improving the transfer accuracy.

[0107] In one embodiment, see Figures 1 to 9 and Fig.11 S40: The step of obtaining feedback signals 2 of the plurality of sensors of the target substrate 40 and confirming the target position where the Micro LED needs to be transferred according to the feedback signals 2 includes:

[0108] S41: Controlling the target substrate 40 to be powered on, so that a portion of the Micro LED chips located on the electrostatic transfer head 20 light up;

[0109] The control signal is sent through the main controller 10 to power on the target substrate 40; after powering on, the receiver substrate 41 on the target substrate 40 forms an electric field. While the target substrate 40 is powered on, the Micro LED chips on the electrostatic transfer head 20 are affected by the electric field, and some of the Micro LED chips light up; the Micro LED chips that light up are Micro LED chips of qualified quality, which are the Micro LED chips that need to be transferred in the present invention. The Micro LED chips that do not light up are Micro LED chips of unqualified quality, which are not the Micro LED chips that need to be transferred in the present invention. In other embodiments, other methods can be used to verify whether the quality of the Micro LED chip is qualified, which are not listed here one by one.

[0110] Since the MicroLED chip 1 is small in size, its position is difficult to control accurately, resulting in low chip transfer efficiency and even chip damage. This embodiment effectively solves the positioning problem of the MicroLED chip 1 in the transfer process of the prior art by controlling the target substrate 40 to be powered on so that part of the MicroLED chip 1 located on the electrostatic transfer head 20 is illuminated, thereby achieving accurate positioning of the chip and greatly improving the transfer efficiency and yield rate of the chip.

[0111] S42: receiving feedback signals 2 collected by the plurality of sensors, wherein the plurality of sensors collecting the feedback signals 2 correspond one to one to the plurality of Micro LED chips lit on the electrostatic transfer head 20;

[0112] A plurality of sensors are installed on a plurality of placement positions 30a of the target substrate 40, and the number of the sensors is consistent with the number of Micro LED chips on the electrostatic transfer head 20; each sensor is aligned with a Micro LED chip position, so that each sensor can independently detect the lighting status of the corresponding Micro LED chip and transmit the collected feedback signal 2 to the main controller 10.

[0113] The present invention further improves the chip transfer accuracy by receiving feedback signals 2 collected by multiple sensors, and the multiple sensors that collect feedback signals 2 correspond one-to-one to multiple Micro LED chips that are lit on the electrostatic transfer head 20. This technical solution enables each lit Micro LED chip to be monitored by a corresponding sensor, so that the position information of each Micro LED chip can be obtained in real time, ensuring the accuracy of the Micro LED chip during the transfer process.

[0114] S43: Analyze the plurality of feedback signals 2 to obtain a target position where the Micro LED needs to be transferred.

[0115] The main controller 10 analyzes the received feedback signal 2 to extract the brightness and position information of the Micro LED chip; based on the analyzed information, the target position of the Micro LED chip to be transferred is determined; based on the target position, the main controller 10 determines the position of the electrode boss 20a on the electrostatic transfer head 20 where the polarity of the current needs to be adjusted, and prepares for the next transfer operation. Through the above steps, the precise positioning and control of the Micro LED chip on the target substrate 40 is achieved.

[0116] The present invention further optimizes the chip transfer process by analyzing multiple feedback signals 2 to obtain the target position of the Micro LED to be transferred. By analyzing the feedback signals 2, the system can accurately determine the target position of each Micro LED chip, thereby achieving fast and accurate transfer of the chip.

[0117] In one embodiment, see Figure 1 , Figure 2 and Fig.10 S50: According to the target position, the electrode boss 20a corresponding to the target position is controlled to pass a negative current so that the Micro LED located at the target position is released to the corresponding placement position 30a on the target substrate 40, and the step also includes:

[0118] According to the target position, the electrode boss 20 a not corresponding to the target position is controlled to pass a positive current, so that the Micro LED not corresponding to the target position continues to be adsorbed on the electrostatic transfer head 20 .

[0119] The present invention realizes independent control of the Micro LED at the target position and the non-target position by precisely controlling the positive and negative currents to be passed through the electrode boss 20a. During the transfer process, by passing a negative current through the electrode boss 20a corresponding to the target position, the Micro LED at the target position is released to the placement position 30a on the target substrate 40. At the same time, by passing a positive current through the electrode boss 20a corresponding to the non-target position, the Micro LED at the non-target position continues to maintain an adsorption state, thereby avoiding possible misoperation and losses during the transfer process. The direct beneficial effect of this technical feature is to significantly improve the transfer efficiency and accuracy of Micro LED.

[0120] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A mass transfer device, characterized in that: The mass transfer device comprises: Base; A main controller, the main controller is arranged on the base; A moving mechanism, the moving mechanism is arranged on the base and is electrically connected to the main controller; An electrostatic transfer head, the electrostatic transfer head is arranged at the end of the moving mechanism; the electrostatic transfer head is provided with a plurality of electrode bosses electrically connected to the main controller, and the plurality of electrode bosses are arranged in an array; A source substrate, the source substrate is disposed on the base and electrically connected to the main controller; the source substrate has a plurality of placement positions arranged in an array, each of the placement positions is used to place a Micro LED chip to be transferred; and a target substrate, the target substrate being disposed on the base and electrically connected to the main controller; the target substrate having a plurality of transfer positions arranged in an array, the transfer positions being used to place the transferred Micro LED chips, each of the transfer positions being provided with a sensor electrically connected to the main controller, the sensor being used to detect the lighting status of the Micro LED chip placed on the transfer position; The source substrate comprises: A second AC power source, which is disposed on the base and electrically connected to the main controller; and a substrate layer, wherein the substrate layer is arranged on a side of the second AC power source facing away from the base; the substrate layer has a plurality of placement positions, each of which is provided with a first connection circuit, and the plurality of first connection circuits are electrically connected to the second AC power source respectively; the first connection circuit is used to connect the Micro LED chip placed at the placement position to the second AC power source.

2. The mass transfer device according to claim 1, characterized in that: The electrostatic transfer head comprises: A first AC power source, which is provided in the mobile mechanism and is electrically connected to the main controller; and a transfer head substrate, wherein the transfer head substrate is arranged on a side of the first AC power source facing away from the moving mechanism; and a plurality of electrode bosses are arranged on a side of the transfer head substrate facing away from the first AC power source and are electrically connected to the first AC power source.

3. The mass transfer device according to claim 2, characterized in that: An insulating dielectric layer is deposited on a side of each electrode boss facing away from the transfer head substrate.

4. The mass transfer device according to claim 1, wherein: The substrate layer comprises: A transition substrate, the transition substrate being arranged on a side of the second AC power source facing away from the base; and an adhesive layer, wherein the adhesive layer is arranged on a side of the transition substrate facing away from the second AC power source, the adhesive layer has a plurality of placement positions, and each placement position is embedded with a first connection circuit, and the adhesive layer is used to bond the Micro LED chip.

5. The mass transfer device according to claim 1, wherein: The target substrate comprises: a receiver substrate, the receiver substrate being disposed on the base; and a plurality of conducting parts, wherein the plurality of conducting parts are all arranged on one side of the receiver substrate and are electrically connected to the main controller respectively; each of the conducting parts has one transfer position, and each of the sensors is embedded in one of the conducting parts.

6. The mass transfer device according to claim 5, characterized in that: The target substrate also includes an insulating contact pad disposed between the receiver substrate and the plurality of vias.

7. The mass transfer device according to claim 5, characterized in that: The sensor is a photoelectric sensor.

8. A transfer control method for a mass transfer device, characterized in that: The mass transfer device is a mass transfer device as claimed in any one of claims 1 to 7; the transfer control method of the mass transfer device comprises: Controlling the moving mechanism to drive the electrostatic transfer head to move until the plurality of electrode bosses of the electrostatic transfer head correspond one by one to the plurality of Micro LED chips to be transferred on the source substrate, and then controlling the moving mechanism to stop running; Controlling the electrostatic transfer head to pass a positive current and the source substrate to pass a negative current, so that each of the MicroLED chips is adsorbed onto the corresponding electrode boss; Controlling the moving mechanism to drive the electrostatic transfer head to approach the target substrate until the Micro LED chip adsorbed on the electrode boss corresponds to a placement position, and then controlling the moving mechanism to stop running; Obtaining a feedback signal from the sensor of the target substrate, and confirming a target position where the Micro LED needs to be transferred according to the feedback signal; According to the target position, the electrode boss corresponding to the target position is controlled to pass a negative current, so that the Micro LED located at the target position is released to a corresponding placement position on the target substrate.

9. The transfer control method of the mass transfer device according to claim 8, characterized in that: The step of obtaining feedback signals from the plurality of sensors of the target substrate and confirming the target position where the Micro LED needs to be transferred according to the feedback signals includes: Controlling the target substrate to be powered on so that a portion of the Micro LED chips located on the electrostatic transfer head illuminates; Receiving feedback signals collected by the plurality of sensors, wherein the plurality of sensors collecting the feedback signals correspond one to one with the plurality of Micro LED chips located on the electrostatic transfer head and emitting light; The plurality of feedback signals are analyzed to obtain a target position where the Micro LED needs to be transferred.

10. The transfer control method of the mass transfer device according to claim 8, characterized in that: According to the target position, before the step of controlling the electrode boss corresponding to the target position to pass a negative current so that the Micro LED located at the target position is released to the corresponding placement position on the target substrate, the step further includes: According to the target position, the electrode boss that does not correspond to the target position is controlled to pass a positive current, so that the Micro LED that does not correspond to the target position continues to be adsorbed on the electrostatic transfer head.

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