Micro light emitting chip bonding method and micro light emitting chip bonding apparatus

Abstract

The application relates to a micro light emitting chip bonding method, which comprises the following steps: placing a plurality of micro light emitting chips on a substrate through mass transfer, and fixing the micro light emitting chips through a glue layer, wherein the pins of each micro light emitting chip are aligned with the pads on the substrate one by one; obtaining the offset of a pressing plate relative to the micro light emitting chips in the plane direction of the substrate, and moving the pressing plate based on the offset, so that the axes of each bump on the pressing plate are respectively coincident with the axes of one micro light emitting chip; and moving the pressing plate along the axis direction of the bump, so that the pins of the micro light emitting chip are in contact with the corresponding pads and are conductive. Through the micro light emitting chip bonding method, the alignment accuracy between the bumps of the pressing plate and the micro light emitting chips can be improved, the bonding effect of the micro light emitting chip is improved, and the micro light emitting chip bonding method with high product yield is provided. The application further provides a micro light emitting chip bonding device.

Description

Technical Field

[0001] This application relates to the field of display technology, specifically to a method for bonding micro-light-emitting chips and a device for performing the method. Background Technology

[0002] Since the size of micro-light-emitting chips is at the micrometer level, in the fabrication process of micro-light-emitting chips, after the step of mass transfer of micro-light-emitting chips to the substrate is completed, it is necessary to press the micro-light-emitting chips down with a pressure plate so that the pins of the micro-light-emitting chips contact the pads of the substrate, thereby completing the bonding of the micro-light-emitting chips on the substrate.

[0003] The bonding pad is typically made of a material with high flatness, such as silicon, to ensure reliable contact and pressure between it and the individual micro-LEDs. However, silicon bonding pads are opaque, making it impossible to implement the existing method of using image sensors to mark alignment through the pad. This affects the precise alignment between the bumps in the bonding pad and their corresponding micro-LEDs, leading to misalignment between the bumps and the micro-LEDs. Uneven force is then applied to the micro-LEDs during pressure application, and the pins of the micro-LEDs cannot reliably align with the substrate pads, reducing the yield rate of the bonded products. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this application is to provide a micro-light-emitting chip bonding method for achieving precise alignment between the bumps on the pressure plate and the micro-light-emitting chip when the pressure plate is opaque, thereby improving the alignment accuracy between the bumps on the pressure plate and the micro-light-emitting chip, and improving the bonding effect and bonding yield of the micro-light-emitting chip. This application also provides a micro-light-emitting chip bonding apparatus for implementing this micro-light-emitting chip bonding method.

[0005] This application provides a method for bonding micro-light-emitting chips, comprising: placing multiple micro-light-emitting chips on a substrate by mass transfer and fixing the micro-light-emitting chips with an adhesive layer, wherein the pins of each micro-light-emitting chip are aligned with the pads on the substrate; obtaining the offset of a pressure plate relative to the micro-light-emitting chips in the planar direction of the substrate, and moving the pressure plate based on the offset so that the axis of each bump on the pressure plate coincides with the axis of a micro-light-emitting chip; and moving the pressure plate along the axis of the bump so that the pins of the micro-light-emitting chips contact and conduct with their corresponding pads.

[0006] In this embodiment, by obtaining the offset of the pressure plate relative to the micro-light-emitting chip in the planar direction of the substrate, and moving the pressure plate based on the offset, the axis of each bump on the pressure plate can be made to coincide with the axis of a micro-light-emitting chip. By moving the pressure plate along the axis of the bump, the bumps of the pressure plate can abut against the micro-light-emitting chip and push the micro-light-emitting chip towards the substrate. At the same time, because the axis of the bump coincides with the axis of the micro-light-emitting chip, the force on the micro-light-emitting chip is balanced, allowing it to move smoothly towards the substrate. This ensures that the pins of the micro-light-emitting chip reliably contact and conduct with their corresponding pads, thereby improving the bonding yield of the micro-light-emitting chip.

[0007] By using the micro-light-emitting chip bonding method of this application, the alignment accuracy between the bumps of the pressure plate and the micro-light-emitting chip can be improved, thereby increasing the bonding yield of the micro-light-emitting chip.

[0008] In one embodiment, obtaining the offset of the pressure plate relative to the micro light-emitting chip in the planar direction of the substrate includes: obtaining a first offset of the bump relative to the zero point of displacement, and obtaining a second offset of the micro light-emitting chip corresponding to the bump relative to the zero point of displacement, wherein the zero point of displacement is a preset reference point on the plane of the substrate; and calculating the offset of the pressure plate relative to the micro light-emitting chip based on the first offset and the second offset.

[0009] In this embodiment, by obtaining a first offset of the bump relative to the zero point of displacement and a second offset of the corresponding micro-light-emitting chip relative to the zero point of displacement, the offset of the bump relative to its corresponding micro-light-emitting chip can be calculated based on the first and second offsets, thereby obtaining the offset of the pressure plate relative to the micro-light-emitting chip. Simultaneously, by setting the zero point of displacement, an absolute position reference can be provided for the offset of the pressure plate relative to the micro-light-emitting chip, thereby improving the accuracy of obtaining the offset of the pressure plate relative to the micro-light-emitting chip.

[0010] In one embodiment, the zero displacement point is located on the substrate.

[0011] In this embodiment, by setting the zero point of displacement on the substrate, the offset of any micro-light-emitting chip on the substrate relative to the zero point of displacement is a fixed value. Therefore, the second offset of the micro-light-emitting chip corresponding to the bump relative to the zero point of displacement is a fixed value. At this time, it is only necessary to obtain the first offset of the bump relative to the zero point of displacement, which simplifies the step of obtaining the offset of the pressure plate relative to the micro-light-emitting chip and further improves the bonding efficiency of the micro-light-emitting chip bonding method of this application.

[0012] In one embodiment, the zero displacement point is located on the stage and on one side of the substrate in the plane direction of the substrate.

[0013] In one embodiment, obtaining a first offset of a bump relative to a zero displacement point includes: moving a pressure plate to obtain a pressing mark of the bump on a marking plate, wherein the marking plate is located on one side of a substrate; and obtaining the offset of the pressing mark relative to the zero displacement point to obtain the first offset.

[0014] In this embodiment, by moving the pressure plate, the pressing marks of the bumps on the marking plate can be obtained. By acquiring the offset of the pressing marks relative to the zero displacement point, the first offset of the bump relative to the zero displacement point can be obtained. Furthermore, by setting the marking plate, when the pressure plate is made of an opaque material, an image sensor can be used to achieve the alignment of each bump on the pressure plate with the micro-light-emitting chip, reducing the cost of implementing the micro-light-emitting chip bonding method of this application, thus making the micro-light-emitting chip bonding method of this application simple and feasible.

[0015] In one embodiment, the zero displacement point is located on the marking plate.

[0016] In one embodiment, obtaining the offset of a pressure plate relative to a micro-light-emitting chip in the planar direction of a substrate includes: obtaining the offset of a bump relative to its corresponding micro-light-emitting chip through an image recognition component, thereby obtaining the offset of the pressure plate relative to the micro-light-emitting chip, wherein the image recognition component is located between the pressure plate and the substrate in the direction where the pads and pins are opposite.

[0017] In this embodiment, by setting an image recognition component and positioning it between the pressure plate and the substrate in the direction opposite to the pad and the pin, the offset of the bump relative to its corresponding micro-light-emitting chip can be obtained. This achieves the effect of obtaining the offset of the pressure plate relative to the micro-light-emitting chip, thereby simplifying the process of obtaining the offset of the pressure plate relative to the micro-light-emitting chip multiple times. This simplifies the steps of the micro-light-emitting chip bonding method of this application and improves the bonding efficiency of the micro-light-emitting chip.

[0018] In one embodiment, obtaining the offset of a bump relative to its corresponding micro-light-emitting chip using an image recognition component includes: identifying the bump using a first image recognition unit in the image recognition component to obtain a first mark, and identifying the micro-light-emitting chip corresponding to the bump using a second image recognition unit in the image recognition component to obtain a second mark; calculating the offset of the first mark relative to the second mark to obtain the offset of the bump relative to its corresponding micro-light-emitting chip.

[0019] In this embodiment, by configuring both the first image recognition unit and the second image recognition unit within the image recognition assembly, and by positioning the first image recognition unit towards the pressure plate, the first image recognition unit can acquire the first mark. Similarly, by positioning the second image recognition unit towards the substrate, the second image recognition unit can acquire the second mark. By calculating the offset of the first mark relative to the second mark, the offset of the bump relative to its corresponding micro-light-emitting chip can be obtained, thereby improving the alignment efficiency between the bumps of the pressure plate and the micro-light-emitting chip, and enhancing the bonding efficiency of the micro-light-emitting chip bonding method of this application.

[0020] In one embodiment, before identifying the bump using a first image recognition unit to obtain a first mark, the method includes: identifying the micro-light-emitting chip corresponding to the bump using a third image recognition unit to obtain an intermediate mark, wherein the field of view of the third image recognition unit is greater than the field of view of the second image recognition unit; calculating the offset between the intermediate mark and the first mark; and moving the pressure plate so that the offset of the bump relative to its corresponding micro-light-emitting chip is within a preset offset range.

[0021] In this embodiment, by providing a third image recognition unit with a field of view larger than that of the second image recognition unit, the third image recognition unit can acquire the recognition mark within a wider field of view. This avoids repeatedly moving the second image recognition unit or substrate to ensure the micro-light-emitting chip with the recognition mark is within the field of view of the second image recognition unit. It is understood that by making the field of view of the third image recognition unit larger than that of the second image recognition unit, displacement errors that may occur during repeated movements of the second image recognition unit or substrate due to the need for precise movement can be avoided. This further improves the alignment accuracy between the bumps on the pressure plate and the micro-light-emitting chip, thereby increasing the bonding yield of the micro-light-emitting chip.

[0022] By moving the pressure plate so that the offset of the bump relative to its corresponding micro-light-emitting chip is within a preset offset range, the first and second image recognition units can be activated. Through the cooperation of the first and second image recognition units, precise positioning between the bump and its corresponding micro-light-emitting chip can be achieved. Furthermore, when the offset between the bump on the pressure plate and its corresponding micro-light-emitting chip is large, the alignment accuracy and efficiency between the bumps on the pressure plate and the micro-light-emitting chip can be improved, thereby improving the bonding effect of the micro-light-emitting chip and increasing product yield.

[0023] In one embodiment, obtaining the offset of the pressure plate relative to the micro light-emitting chip in the planar direction of the substrate includes: obtaining the offset of the bump relative to the corresponding micro light-emitting chip based on a scale.

[0024] In this embodiment, by setting a scale, a proportional reference can be provided for obtaining the offset of the bump relative to its corresponding micro light-emitting chip, so as to determine the true offset of the bump relative to its corresponding micro light-emitting chip at different magnification ratios. This allows the micro light-emitting chip bonding method of this application to obtain the offset of the bump relative to its corresponding micro light-emitting chip at different magnification ratios, thereby improving the alignment accuracy between the bump of the pressure plate and the micro light-emitting chip.

[0025] In one embodiment, the scale is located on a marking plate or substrate.

[0026] In one embodiment, the scale is located on one side of the substrate in the plane direction of the substrate.

[0027] In one embodiment, the scale is any one of a straight line segment, an arc segment, a circle, a rectangle, or a triangle.

[0028] In this embodiment, by setting the scale to any one of a straight line segment, an arc segment, a circle, a rectangle, or a triangle, a proportional reference can be provided to obtain the offset of the bump relative to its corresponding micro light-emitting chip, so as to obtain the true offset between the bump and its corresponding micro light-emitting chip.

[0029] In one embodiment, the zero displacement point is located at the geometric center of the scale.

[0030] In this embodiment, by simultaneously setting a zero displacement point and a scale, and setting the zero displacement point to be located at the geometric center of the scale, the zero displacement point can provide an absolute position reference for obtaining the offset of the pressure plate relative to the micro light-emitting chip, while the scale can provide a proportional reference for obtaining the actual offset of the pressure plate relative to the micro light-emitting chip.

[0031] In one embodiment, obtaining the offset of the pressure plate relative to the micro light-emitting chip in the planar direction of the substrate includes: obtaining the offset of at least two bumps relative to their corresponding micro light-emitting chips; and calculating the average of the offsets of the at least two bumps relative to their corresponding micro light-emitting chips to obtain the offset of the pressure plate relative to the micro light-emitting chip.

[0032] In this embodiment, by calculating the average of the offsets of at least two bumps relative to their corresponding micro-light-emitting chips, the offset of the pressure plate relative to the micro-light-emitting chip is obtained. This eliminates the situation where the bumps on the pressure plate cannot be fully aligned with the micro-light-emitting chip due to manufacturing errors that may exist in a single bump. This ensures that all the bumps on the pressure plate are fully aligned with the micro-light-emitting chip, thereby improving the bonding reliability and bonding effect of the micro-light-emitting chip bonding method of this application.

[0033] In one embodiment, obtaining the offset of at least two bumps relative to their corresponding micro-light-emitting chips includes: obtaining the offset of at least two bumps relative to their corresponding micro-light-emitting chips, wherein the bump array is arranged, and the at least two bumps include a first bump and a second bump, the first bump and the second bump being located at opposite ends of the diagonal in the array of bumps.

[0034] In this embodiment, by setting the first bump and the second bump to be located at the two ends of the diagonal of the bumps in the array, the alignment accuracy between the bumps of the pressure plate and the micro light-emitting chip can be further improved by aligning the two bumps that are farthest apart in the array with their corresponding micro light-emitting chips, thereby improving the bonding effect of the micro light-emitting chip.

[0035] This application also provides a micro-light-emitting chip bonding apparatus, including a stage, a pressure plate, an image recognition component, and a controller. The stage is used to support the substrate after mass transfer. The pressure plate includes multiple bumps, all of which are disposed facing the substrate. The image recognition component is used to obtain the offset of the pressure plate relative to the micro-light-emitting chips on the substrate in the planar direction of the substrate. The controller is used to move the pressure plate based on the offset, so that the axis of each bump on the pressure plate coincides with the axis of a micro-light-emitting chip. The controller is also used to move the pressure plate along the axial direction of the bumps, so that the micro-light-emitting chips contact the substrate and conduct electricity.

[0036] In this embodiment, a stage is provided to support the substrate, enabling the bonding of micro-light-emitting chips to be performed on the stage. A pressure plate is provided, with protrusions on the side of the pressure plate facing the substrate. These protrusions push the micro-light-emitting chips towards the substrate, allowing them to contact and conduct electricity. An image recognition component is provided to acquire the offset of the pressure plate relative to the micro-light-emitting chips on the substrate in the planar direction. A controller is provided to move the pressure plate based on this offset, ensuring that the axes of each protrusion on the pressure plate coincide with the axis of a micro-light-emitting chip, thus guaranteeing effective bonding between the micro-light-emitting chips and the substrate. The controller also allows for the movement of the pressure plate along the axial direction of the protrusions, enabling the protrusions on the pressure plate to push the micro-light-emitting chips towards the substrate.

[0037] Furthermore, the micro-light-emitting chip bonding apparatus of this application can realize and execute the micro-light-emitting chip bonding method described in any of the above embodiments. Simultaneously, because the micro-light-emitting chip bonding apparatus of this application can realize and execute the micro-light-emitting chip bonding method described in any of the above embodiments, the micro-light-emitting chip bonding method of this application possesses all the possible beneficial effects of the micro-light-emitting chip bonding method described in any of the above embodiments. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the working scenario of the micro-light-emitting chip bonding method of this application;

[0039] Figure 2 This is a schematic diagram illustrating the workflow of the micro-light-emitting chip bonding method of this application;

[0040] Figure 3 This is a schematic diagram of the structure from one side of the viewpoint when a micro-light-emitting chip is transferred via mass transfer.

[0041] Figure 4 This is a schematic diagram of the structure from one side of the viewpoint when a micro-light-emitting chip is transferred via mass transfer.

[0042] Figure 5 A schematic diagram of the workflow for obtaining the offset of the pressure plate relative to the micro light-emitting chip in the planar direction of the substrate;

[0043] Figure 6 A schematic diagram of the workflow for obtaining the first offset of the bump relative to the zero point of displacement;

[0044] Figure 7 A schematic diagram of the structure from one side when moving the pressure plate to obtain the downward pressure mark of the bump on the marking plate;

[0045] Figure 8 for Figure 5 A schematic diagram of the planar structure of the stage in the illustrated embodiment;

[0046] Figure 9 This is a schematic diagram of the planar structure of the platform in this embodiment;

[0047] Figure 10 A schematic diagram of the structure from one side when the protrusions of the pressure plate are aligned with the micro light-emitting chip;

[0048] Figure 11 This is a schematic diagram illustrating the workflow of obtaining offsets using an image recognition component in one embodiment;

[0049] Figure 12 This is a schematic diagram of a structure for obtaining the viewpoint on one side of the offset using an image recognition component in one embodiment.

[0050] Figure 13 for Figure 12 A schematic diagram of the planar structure of the embodiment shown, with some parts of the structure hidden;

[0051] Figure 14 This is a schematic diagram illustrating the workflow for obtaining the offset of the pressure plate relative to the micro light-emitting chip in the planar direction of the substrate in one embodiment.

[0052] Figure 15This is a schematic diagram of the planar structure in one embodiment for obtaining the offset of the pressure plate relative to the micro light-emitting chip in the planar direction of the substrate;

[0053] Figure 16 This is a schematic diagram of the structure of a micro LED chip when its pins are in contact with their corresponding pads, viewed from one side. Detailed Implementation

[0054] 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.

[0055] The following descriptions of the embodiments are based on the accompanying illustrations and are used to illustrate specific embodiments in which this application can be implemented. The component designations used herein, such as "first," "second," etc., are merely for distinguishing the described objects and do not have any sequential or technical meaning. Unless otherwise specified, the terms "connection" and "linkage" used in this application include both direct and indirect connections (linkages). Directional terms used in this application, such as "up," "down," "front," "rear," "left," "right," "inner," "outer," "side," etc., are merely for reference to the accompanying drawings. Therefore, the use of directional terms is for better and clearer explanation and understanding of this application, and does not indicate or imply that the referred device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this application.

[0056] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joint" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising," "may include," "include," or "may include" used in this application indicate the presence of the corresponding disclosed function, operation, element, etc., and do not limit one or more other functions, operations, elements, etc. Moreover, the terms "comprising" or "include" indicate the presence of the corresponding features, number, steps, operations, elements, components, or combinations thereof disclosed in the specification, but do not exclude the presence or addition of one or more other features, number, steps, operations, elements, components, or combinations thereof, and are intended to cover non-exclusive inclusion.

[0057] 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.

[0058] Please see Figure 1 , Figure 1 This is a schematic diagram of the working scenario of the micro-light-emitting chip bonding method of this application. During the manufacturing process of the micro-light-emitting chip 1, after the micro-light-emitting chip 1 is manufactured, it is necessary to transfer the micro-light-emitting chip 1 in large quantities onto the substrate 2, and bond the pins 11 of the micro-light-emitting chip 1 to the pads 21 protruding on the substrate 2, so as to achieve the effect of electrical conduction and lighting of the micro-light-emitting chip 1.

[0059] This application presents a micro-light-emitting chip bonding method for implementing the bonding process between the pins 11 and pads 21 of a micro-light-emitting chip 1. Specifically, as shown... Figure 1 As shown, multiple pads 21 are arranged in an array on one side surface of the substrate 2. The micro light-emitting chip 1 and the pads 21 are located on the same side of the substrate 2, and the pins 11 of each micro light-emitting chip 1 correspond to and are fixedly connected to a pad 21, so that each pin 11 contacts the pad 21, thereby achieving the effect of conducting and lighting up the micro light-emitting chip 1.

[0060] The fixed connection between the pin 11 of the micro light-emitting chip 1 and the pad 21 can be achieved by methods such as thermo-compression bonder (TCB), ultrasonic bonder (USB), or thermo-supersonic bonder.

[0061] It should be noted that the micro-light-emitting chip 1 can be a light-emitting chip with a size at the micrometer level, such as a Micro-LED (Micro Light Emitting Diode), or a smaller Mini-LED (Mini Light Emitting Diode). In other embodiments of this application, the micro-light-emitting chip 1 described herein can also be a light-emitting chip of other sizes.

[0062] Please see Figure 2 , Figure 2 This is a schematic diagram illustrating the workflow of the micro-light-emitting chip bonding method of this application.

[0063] like Figure 2 As shown, the micro-light-emitting chip bonding method of this application includes:

[0064] Step S100: Multiple micro-light-emitting chips 1 are placed on substrate 2 by mass transfer, and micro-light-emitting chips 1 are fixed by adhesive layer 3, wherein the pins 11 of each micro-light-emitting chip 1 are aligned with the pads 21 on substrate 2.

[0065] Please refer to the following for details. Figure 3 and Figure 4 , Figure 3 This is a schematic diagram of the structure from one side when the micro-light-emitting chip 1 is transferred via mass transfer. Figure 4 This is a schematic diagram of the structure from one side when the micro-light-emitting chip 1 is transferred onto the adhesive layer 3. In step S100, "multiple micro-light-emitting chips 1 are placed on the substrate 2 by mass transfer and the micro-light-emitting chips 1 are fixed by the adhesive layer 3", multiple micro-light-emitting chips 1 are transferred onto the substrate 2 by mass transfer methods such as fluid self-assembly technology, stamp gripping technology, selective release technology, and roller transfer technology.

[0066] exist Figure 3 In the illustrated embodiment, substrate 2 is placed on stage 5, and a large number of micro-light-emitting chips 1 are transferred onto substrate 2 using a direct transfer method. Figure 3As shown, a plurality of pads 21 are arranged in an array on the side of the substrate 2 away from the stage 5. The pads 21 are made of conductive material to enable the micro-light-emitting chip 1 to conduct electricity after contacting the pins 11 of the micro-light-emitting chip 1, and to control the light emission of the micro-light-emitting chip 1. An adhesive layer 3 is also coated between the plurality of pads 21 so that the adhesive layer 3 covers the pads 21.

[0067] Multiple micro-light-emitting chips 1 are located on a carrier substrate 4 and arranged in an array on the carrier substrate 4. The carrier substrate 4 can be a substrate made of materials such as glass, ceramic, silicon, or sapphire. Figure 3 In the embodiment shown, the carrier substrate 4 is made of a transparent material.

[0068] The carrier substrate 4 is moved to the side of the pad 21 away from the substrate 2, and the micro-light-emitting chip 1 on the carrier substrate 4 is oriented towards the adhesive layer 3. On the side of the carrier substrate 4 away from the micro-light-emitting chip 1, a laser L can be emitted by a laser emitter, and the laser L passes through the transparent carrier substrate 4 to act on the micro-light-emitting chip 1, thereby peeling the micro-light-emitting chip 1 off the carrier substrate 4, so as to achieve the effect of directly transferring the micro-light-emitting chip 1 onto the adhesive layer 3.

[0069] Furthermore, such as Figure 4 As shown, after the micro-light-emitting chips 1 are transferred onto the adhesive layer 3, the position and spacing of the micro-light-emitting chips 1 can be adjusted using a fine-tuning device (not shown in the figure) or other means. This allows the orientation and spacing between the multiple micro-light-emitting chips 1 to be arranged in an array on the side of the adhesive layer 3 away from the substrate, and the pins 11 of each micro-light-emitting chip 1 to be aligned with the pads 21 on the substrate 2. It is understandable that when a large number of micro-light-emitting chips 1 are transferred onto the adhesive layer 3, the adhesive layer 3 can effectively hold and fix the micro-light-emitting chips 1.

[0070] Step S200: Obtain the offset S of the pressure plate 6 relative to the micro light-emitting chip 1 in the plane direction of the substrate 2, and move the pressure plate 6 based on the offset S so that the axis of each protrusion 61 on the pressure plate 6 coincides with the axis of a micro light-emitting chip 1.

[0071] Please see Figure 5 , Figure 5 A schematic diagram illustrating the workflow for obtaining the offset S of the pressure plate 6 relative to the micro-light-emitting chip 1 in the planar direction of the substrate 2. Figure 5 In the illustrated embodiment, step S200, "obtaining the offset S of the pressure plate 6 relative to the micro light-emitting chip 1 in the planar direction of the substrate 2," includes:

[0072] S210. Obtain the first offset S1 of the bump 61 relative to the zero point O, and obtain the second offset S2 of the micro light-emitting chip 1 corresponding to the bump 61 relative to the zero point O, wherein the zero point O is a preset reference point on the plane of the substrate 2.

[0073] For details, please refer to Figure 6 , Figure 6 This is a schematic diagram illustrating the workflow for obtaining the first offset S1 of bump 61 relative to the zero displacement point O. Figure 6 In the illustrated embodiment, step S210, "obtaining the first offset S1 of the bump 61 relative to the zero displacement point O," includes:

[0074] S211, Move the pressure plate 6 to obtain the pressing mark M of the bump 61 on the marking plate 7, wherein the marking plate 7 is located on one side of the substrate 2.

[0075] Please see Figure 7 , Figure 7 A schematic diagram of the structure from one side when moving the pressure plate 6 to obtain the downward pressure mark M of the protrusion 61 on the marking plate 7. (See diagram below.) Figure 7 As shown, the pressure plate 6 has a plurality of protrusions 61 on the side facing the substrate 2. Each protrusion 61 of the pressure plate 6 is used to press down the micro light-emitting chip 1 so that the micro light-emitting chip 1 moves toward the substrate 2 and contacts and conducts electricity with the pad 21.

[0076] Specifically, in Figure 7 In the illustrated embodiment, a plurality of bumps 61 are arranged in an array, and the array of bumps 61 corresponds one-to-one with a plurality of micro-light-emitting chips 1 arranged in an array on the adhesive layer 3. In other words, the spacing between the plurality of bumps 61 in each direction is the same as the spacing between the plurality of micro-light-emitting chips 1 in the same direction.

[0077] In order to ensure reliable contact and pressure between the bump 61 and each micro light-emitting chip 1, in Figure 7 In the embodiment shown, the bump 61 is made of a material with high flatness, such as silicon.

[0078] like Figure 7 As shown, a marking plate 7 is placed on the stage 5. The marking plate 7 is used to form pressing marks M on its surface that correspond one-to-one with each of the protrusions 61 on the pressure plate 6 when it abuts against the protrusions 61. The marking plate 7 is located on one side of the substrate 2 in the planar direction of the substrate 2.

[0079] Furthermore, the pressure plate 6 is moved to obtain the pressing mark M of the protrusion 61 on the marking plate 7. Specifically, as... Figure 7As shown, the pressure plate 6 is moved along the direction opposite to the pin 11 and pad 21 of the micro light-emitting chip 1, so that the pressure plate 6 moves toward the imprint plate 7. When the bumps 61 of the pressure plate 6 abut against the side of the imprint plate 7 away from the stage 5, each bump 61 of the pressure plate 6 will form a pressing mark M on the imprint plate 7 corresponding to each bump 61.

[0080] Understandably, the arrangement of each pressing mark M on the imprint plate 7, as well as the spacing between them in each direction, are the same as those of each bump 61.

[0081] It should be noted that, in Figure 7 The arrangement and position of the pressure mark M are only shown as an example in this application embodiment and do not represent the specific structure of the pressure mark M formed by each bump 61 on the imprint plate 7.

[0082] S212. Obtain the offset of the pressure mark M relative to the zero displacement point O to obtain the first offset S1.

[0083] Please see Figure 8 , Figure 8 for Figure 5 A schematic diagram of the planar structure of the platform 5 in the illustrated embodiment. (See attached diagram.) Figure 8 As shown, a displacement zero point O is also provided in the planar direction of the substrate 2. The displacement zero point O is a preset reference point on the plane of the substrate 2, which is used to provide an absolute position reference for the offset S of the pressure plate 6 relative to the micro light-emitting chip 1. Figure 8 In the embodiment shown, the zero displacement point O is located on the surface of the stage 5 used to support the substrate 2, and is located between the substrate 2 and the imprint plate 7 in the direction opposite to the substrate 2 and the imprint plate 7.

[0084] Through the image sensor CCD (see also) Figure 7 Obtain the offset of the pressure mark M relative to the zero displacement point O to obtain the first offset S1, that is, obtain the first offset S1 of the bump 61 relative to the zero displacement point O.

[0085] Specifically, in Figure 8 In the illustrated embodiment, the substrate 2 and the marking plate 7 are arranged opposite each other along a first direction X in the planar direction of the substrate 2, and the zero displacement point O is located between the substrate 2 and the marking plate 7 along the first direction X. The protrusion 61 of the pressure plate 6 includes a first protrusion 61a (e.g., ...). Figure 7 As shown), the first bump 61a has a first pressing mark M1 formed on the imprint plate 7.

[0086] Using an image sensor CCD with the geometric center point of the first pressure mark M1 as the identification marker, the offset of the first pressure mark M1 relative to the displacement zero point O is obtained to form the first offset S1. Further, as... Figure 8As shown, the micro light-emitting chip 1 corresponding to the first bump 61a is the first micro light-emitting chip 1a. The first micro light-emitting chip 1a is offset relative to the zero displacement point O by the geometric center point of the first micro light-emitting chip 1a in the plane direction of the substrate 2 using the image sensor CCD as the identification mark, so as to form the second offset S2.

[0087] It should be noted that, Figure 8 In the illustrated embodiment, only the geometric center point of the first pressing mark M1 formed by the first protrusion 61a and the geometric center point of the first micro light-emitting chip 1a in the planar direction of the substrate 2 are used as identification marks for illustration. In other embodiments of this application, the side of the first pressing mark M1 or other structural features can also be used as identification marks, and the side of the first micro light-emitting chip 1a in the planar direction of the substrate 2 or other structural features can also be used as identification marks.

[0088] In one embodiment, the zero displacement point O is located on the substrate 2.

[0089] In this embodiment, by setting the zero point of displacement O on the substrate 2, the offset of any micro light-emitting chip 1 on the substrate 2 relative to the zero point of displacement O is a fixed value. Therefore, the second offset S2 of the micro light-emitting chip 1 corresponding to the bump 61 relative to the zero point of displacement O is a fixed value. At this time, it is only necessary to obtain the first offset S1 of the bump 61 relative to the zero point of displacement O, which simplifies the step of obtaining the offset S of the pressure plate 6 relative to the micro light-emitting chip 1 and further improves the bonding efficiency of the micro light-emitting chip bonding method of this application.

[0090] In one embodiment, the zero displacement point O is located on the marking plate 7.

[0091] Step S220: Calculate the offset of the pressure plate 6 relative to the micro light-emitting chip 1 based on the first offset S1 and the second offset S2.

[0092] In step S220, “Calculate the offset of the pressure plate 6 relative to the micro light-emitting chip 1 based on the first offset S1 and the second offset S2”, the first offset S1 of the bump 61 relative to the zero point of displacement O and the second offset S2 of the micro light-emitting chip 1 corresponding to the bump 61 relative to the zero point of displacement O are obtained by the image sensor CCD, and the offset S of the pressure plate 6 relative to the micro light-emitting chip 1 is calculated based on the obtained first offset S1 and second offset S2.

[0093] Specifically, in Figure 8 In the embodiment shown, the zero displacement point O is located between the substrate 2 and the imprint plate 7 along the first direction X. By calculating the sum of the first offset S1 and the second offset S2, the offset S of the pressure plate 6 relative to the micro light-emitting chip 1 can be obtained.

[0094] In other embodiments of this application, when the zero displacement point O is located on the same side of the substrate 2 and the imprint plate 7 along the first direction X, the offset S of the pressure plate 6 relative to the micro light-emitting chip 1 is obtained by calculating the difference between the first offset S1 and the second offset S2.

[0095] Understandably, in this embodiment, by moving the pressure plate 6, the pressing mark M of the protrusion 61 on the marking plate 7 can be obtained. And by obtaining the offset S of the pressing mark M relative to the displacement zero point O, the first offset S1 of the protrusion 61 relative to the displacement zero point O can be obtained. Furthermore, by setting the marking plate 7, when the pressure plate 6 is made of an opaque material, an image sensor can be used to achieve the alignment effect between each protrusion 61 on the pressure plate 6 and the micro-light-emitting chip 1, and the cost of implementing the micro-light-emitting chip bonding method of this application can be reduced, thus making the micro-light-emitting chip bonding method of this application simple and feasible.

[0096] It should be noted that, in Figure 8 In the embodiment shown, since the bump 61 and its corresponding micro light-emitting chip 1 are arranged opposite each other along the first direction X, there is no offset between them in the second direction Y. That is, the first bump 61a and the first micro light-emitting chip 1a are offset only in the first direction X.

[0097] In other embodiments of this application, when the protrusion 61 of the pressure plate 6 and its corresponding micro light-emitting chip 1 are offset in both the first direction X and the second direction Y, the first offset S1 includes the offset of the protrusion 61 relative to the displacement zero point O in the first direction X and the second direction Y, and the second offset S2 includes the offset of the micro light-emitting chip 1 corresponding to the protrusion 61 relative to the displacement zero point O in the first direction X and the second direction Y. Figure 8 The illustrated embodiment is provided as an example only, with the first bump 61a and the first micro-light-emitting chip 1a offset only in the first direction X. The first direction X and the second direction Y are perpendicular to each other.

[0098] For example, in one possible embodiment, such as Figure 9 As shown, Figure 9 This is a schematic diagram of the planar structure of platform 5 in this embodiment. Figure 9 As shown, the pressure plate 6 is offset relative to the substrate 2 in both the first direction X and the second direction Y, that is, the protrusion 61 on the pressure plate is offset relative to the corresponding micro light-emitting chip 1 in both the first direction X and the second direction Y.

[0099] Understandably, at this time, the first offset S1X of the first pressing mark M1 relative to the displacement zero point O in the first direction X, and the first offset S1Y of the first pressing mark M1 relative to the displacement zero point O in the second direction Y are obtained. The second offset S2X of the first micro light-emitting chip 1a corresponding to the first pressing mark M1 relative to the displacement zero point O in the first direction X, and the second offset S2Y of the first pressing mark M1 relative to the displacement zero point O in the second direction Y are obtained.

[0100] Based on the first offset S1X of the first pressing mark M1 relative to the zero point O in the first direction X and the first offset S1Y of the first offset S1Y of the first offset S2X of the first micro light-emitting chip 1a relative to the zero point O in the first direction X and the second offset S2Y of the first micro light-emitting chip 1a relative to the zero point O in the second direction Y, the offset SX of the protrusion 61 of the pressure plate 6 relative to its corresponding micro light-emitting chip 1 in the first direction X and the offset SY in the second direction Y are calculated.

[0101] Specifically, in Figure 9 In the embodiment shown, the sum of the first offset S1X and the second offset S2Y is calculated to obtain the offset SX of the first pressing mark M1 formed by the first bump 61 relative to its corresponding first micro light-emitting chip 1a in the first direction X, so as to obtain the offset SX of the bump 61 on the pressure plate 6 relative to its corresponding micro light-emitting chip 1 in the first direction X.

[0102] Calculate the difference between the first offset S1Y and the second offset S2Y to obtain the offset SY of the first pressing mark M1 formed by the first bump 61 relative to its corresponding first micro light-emitting chip 1a in the second direction Y, so as to obtain the offset SY of the bump 61 on the pressure plate 6 relative to its corresponding micro light-emitting chip 1 in the second direction Y.

[0103] Understandably, in steps S210 ("obtaining the first offset S1 of the bump 61 relative to the displacement zero point O, and obtaining the second offset S2 of the micro-light-emitting chip 1 corresponding to the bump 61 relative to the displacement zero point O") and S220 ("calculating the offset of the pressure plate 6 relative to the micro-light-emitting chip 1 based on the first offset S1 and the second offset S2"), by obtaining the first offset S1 of the bump 61 relative to the displacement zero point O and the second offset S2 of the micro-light-emitting chip 1 corresponding to the bump 61 relative to the displacement zero point O, the offset S of the bump 61 relative to its corresponding micro-light-emitting chip 1 can be calculated based on the first offset S1 and the second offset S2, thereby obtaining the offset S of the pressure plate 6 relative to the micro-light-emitting chip 1. Simultaneously, by setting the displacement zero point O, an absolute position reference can be provided for the offset S of the pressure plate 6 relative to the micro-light-emitting chip 1, thereby improving the accuracy of obtaining the offset S of the pressure plate 6 relative to the micro-light-emitting chip 1.

[0104] One embodiment is also described below. Figure 9 In this embodiment, step S200, "obtaining the offset S of the pressure plate 6 relative to the micro light-emitting chip 1 in the planar direction of the substrate 2," includes:

[0105] Step S200a: Obtain the offset S of the bump 61 relative to its corresponding micro light-emitting chip 1 based on the scale 8.

[0106] Specifically, in Figure 9 In the illustrated embodiment, the scale 8 is located on one side of the substrate 2 in the planar direction of the substrate 2. In other words, the scale 8 is disposed on the stage 5 and located on one side of the substrate 2. The scale 8 is in the shape of a line segment.

[0107] Understandably, in this embodiment, by setting the scale 8, a proportional reference can be provided for obtaining the offset S of the bump 61 relative to its corresponding micro light-emitting chip 1, so as to determine the true offset of the bump 61 relative to its corresponding micro light-emitting chip 1 at different magnification ratios. This enables the micro light-emitting chip bonding method of this application to obtain the offset S of the bump 61 relative to its corresponding micro light-emitting chip 1 at different magnification ratios, thereby improving the alignment accuracy between the bump 61 of the pressure plate 6 and the micro light-emitting chip 1.

[0108] It should be noted that, in Figure 9In the illustrated embodiment, the shape of the ruler 8 is described as a straight line segment only as an example, but it does not mean that the shape of the ruler 8 in this application is limited to a straight line segment. In other embodiments of this application, the shape of the ruler 8 can also be any one of an arc segment, a circle, a rectangle or a triangle, or it can also be any other shape that can provide a reference for obtaining the true and definite offset S of the bump 61 relative to its corresponding micro light-emitting chip 1 at different magnification ratios.

[0109] Understandably, by setting the scale 8 to any one of the following: a straight line segment, an arc segment, a circle, a rectangle, or a triangle, a proportional reference can be provided to obtain the offset S of the bump 61 relative to its corresponding micro light-emitting chip 1, so as to obtain the true offset between the bump 61 and its corresponding micro light-emitting chip 1.

[0110] At the same time, Figure 9 In the illustrated embodiment, the scale 8 is described as being located on the stage 5 only as an example, but it does not mean that the scale 8 is limited to being located on the stage 5 in this application. In other embodiments of this application, the scale 8 may also be located on the marking plate 7 or on the substrate 2.

[0111] One embodiment is also described below. Figure 9 .like Figure 9 As shown, the zero displacement point O is located at the geometric center of scale 8.

[0112] Understandably, in this embodiment, by simultaneously setting the zero displacement point O and the scale 8, and setting the zero displacement point O to be located at the geometric center of the scale 8, the zero displacement point O can provide an absolute position reference for obtaining the offset S of the pressure plate 6 relative to the micro light-emitting chip 1, while the scale 8 can provide a proportional reference for obtaining the actual offset S of the pressure plate 6 relative to the micro light-emitting chip 1.

[0113] For further details, please refer to Figure 10 , Figure 10 This is a schematic diagram of the structure from one side when the protrusion 61 of the pressure plate 6 is aligned with the micro light-emitting chip 1. Figure 10 As shown, based on the offset S of the protrusion 61 of the pressure plate 6 relative to its corresponding micro light-emitting chip 1, the pressure plate 6 is moved so that the axis of each protrusion 61 on the pressure plate 6 coincides with the axis of a micro light-emitting chip 1.

[0114] In one embodiment, step S200, "obtaining the offset S of the pressure plate 6 relative to the micro light-emitting chip 1 in the planar direction of the substrate 2," includes:

[0115] Step S200b: Obtain the offset S of the bump 61 relative to its corresponding micro light-emitting chip 1 through the image recognition component 91, so as to obtain the offset S of the pressure plate 6 relative to the micro light-emitting chip 1, wherein the image recognition component 91 is located between the pressure plate 6 and the substrate 2 in the direction opposite to the pad 21 and the pin 11.

[0116] For details, please refer to Figure 11 , Figure 11 This is a schematic diagram illustrating the workflow of obtaining the offset S of the bump 61 relative to its corresponding micro-light-emitting chip 1 using the image recognition component 91 in this embodiment. Figure 11 As shown, step S200b, "obtaining the offset S of the bump 61 relative to its corresponding micro-light-emitting chip 1 through the image recognition component 91," includes the following steps:

[0117] S230b: The first image recognition unit 911 in the image recognition component 91 identifies the bump 61 to obtain the first mark A1, and the second image recognition unit 912 in the image recognition component 91 identifies the micro light-emitting chip 1 corresponding to the bump 61 to obtain the second mark A2.

[0118] For details, please refer to Figure 12 , Figure 12 This is a structural schematic diagram showing the viewpoint from one side of the image recognition component 91, which obtains the offset S of the bump 61 relative to its corresponding micro-light-emitting chip 1. (See diagram below.) Figure 12 As shown, the image recognition component 91 is located between the pressure plate 6 and the substrate 2 in the direction where the pad 21 of the substrate 2 is opposite to the pin 11 of the micro light-emitting chip 1. It includes a first image recognition unit 911 and a second image recognition unit 912, and the first image recognition unit 911 and the second image recognition unit 912 are arranged opposite to each other in the direction where the pad 21 is opposite to the pin 11.

[0119] Among them, Figure 12 In the illustrated embodiment, the first image recognition unit 911 is closer to the pressure plate 6 than the second image recognition unit 912, and the second image recognition unit 912 is closer to the substrate 2 than the first image recognition unit 911. In other words, the first image recognition unit 911 faces the protrusion 61 of the pressure plate 6 and is used to identify the mark on the protrusion 61 to obtain a first mark A1. The second image recognition unit 912 is positioned facing the micro-light-emitting chip 1 and is used to identify the mark on the micro-light-emitting chip 1 corresponding to the protrusion 61 to obtain a second mark A2.

[0120] Among them, Figure 12In the embodiment shown, the geometric center point of the first bump 61a in the planar direction of the substrate 2 is used as the identification mark to form a first mark A1, and the geometric center point of the first micro light-emitting chip 1a corresponding to the first bump 61a in the planar direction of the substrate 2 is used as the identification mark to form a second mark A2.

[0121] It should be noted that, in other embodiments of this application, the side edge of the first bump 61a in the plane direction of the substrate 2 or other structural features can also be used as the identification mark of the first bump 61a, namely, the first mark A1. The side edge of the first micro-light-emitting chip 1a corresponding to the first bump 61a in the plane direction of the substrate 2 can also be used as the identification mark of the first micro-light-emitting chip 1a, namely, the second mark A2.

[0122] S240b Calculate the offset S12 of the first mark A1 relative to the second mark A2 to obtain the offset S of the bump 61 relative to its corresponding micro light-emitting chip 1.

[0123] Specifically, such as Figure 12 As shown, the offset S12 of the first mark A1 relative to the second mark A2 is the offset S of the first bump 61a relative to the first micro light-emitting chip 1a, which is also the offset S of the bump 61 relative to its corresponding micro light-emitting chip 1.

[0124] Understandably, in this embodiment, by setting the image recognition component 91 and positioning it between the pressure plate 6 and the substrate 2 in the direction opposite to the pad 21 and the pin 11, the offset S of the bump 61 relative to its corresponding micro-light-emitting chip 1 can be obtained. This achieves the effect of obtaining the offset S of the pressure plate 6 relative to the micro-light-emitting chip 1, thereby simplifying the process of obtaining the offset S of the pressure plate 6 relative to the micro-light-emitting chip 1 multiple times. This simplifies the steps of the micro-light-emitting chip bonding method of this application and improves the bonding efficiency of the micro-light-emitting chip.

[0125] Furthermore, in this embodiment, by setting both the first image recognition unit 911 and the second image recognition unit 912 in the image recognition component 91, and by setting the first image recognition unit 911 to face the pressure plate 6, the first image recognition unit 911 can acquire the first mark A1, and by setting the second image recognition unit 912 to face the substrate 2, the second image recognition unit 912 can acquire the second mark A2.

[0126] By calculating the offset S12 of the first mark A1 relative to the second mark A2, the offset S of the bump 61 relative to its corresponding micro light-emitting chip 1 can be obtained, thereby improving the efficiency of the alignment of each bump 61 of the pressure plate 6 with the micro light-emitting chip 1 and improving the bonding efficiency of the micro light-emitting chip bonding method of this application.

[0127] One embodiment is also described below. Figure 11 and Figure 13 , Figure 13 for Figure 12 The illustrated embodiment is a planar structural diagram with some parts of the structure hidden. (See attached diagram.) Figure 11 As shown, before step S230b "identifying the bump 61 through the first image recognition unit 911 to obtain the first mark A1", the following steps are included:

[0128] Step S210b: The micro-light-emitting chip 1 corresponding to the bump 61 is identified by the third image recognition unit 913 to obtain the intermediate mark A0, wherein the field of view of the third image recognition unit 913 is greater than the field of view of the second image recognition unit 912;

[0129] like Figure 13 As shown, the third image recognition unit 913 is also disposed within the image recognition component 91, and is located on the side closer to the substrate 2 along the direction opposite to the pin 11 of the micro-light-emitting chip 1 on the pad 21 of the substrate 2, and is positioned towards the micro-light-emitting chip 1, for recognizing the recognition mark on the micro-light-emitting chip 1 corresponding to the bump 61, in order to obtain the intermediate mark A0. The field of view of the third image recognition unit 913 is greater than that of the second image recognition unit 912.

[0130] Specifically, in Figure 13 In the illustrated embodiment, the third image recognition unit 913 can be a wide-angle camera, and the second image recognition unit 912 can be a positioning camera. In other words, compared to the second image recognition unit 912, the third image recognition unit 913 can recognize a larger range of recognition marks at the same location, and thus can find the intermediate mark A0 of the micro-light-emitting chip 1 corresponding to the bump 61 over a larger range.

[0131] Step S220b: Calculate the offset S02 between the intermediate mark A0 and the first mark A1, and move the pressure plate 6 so that the offset S of the bump 61 relative to its corresponding micro light-emitting chip 1 is within the preset offset range.

[0132] Specifically, such as Figure 13 As shown, the identification mark of the first micro light-emitting chip 1a is obtained by the third image recognition unit 913 to obtain the intermediate mark A0, and the offset S02 between the intermediate mark A0 and the second mark A2 is calculated.

[0133] Based on the offset S02 between the intermediate mark A0 and the second mark A2, the pressure plate 6 is moved so that the offset S of the protrusion 61 on the pressure plate 6 relative to its corresponding micro light-emitting chip 1 is within a preset offset range after the movement, thus achieving a coarse positioning effect of the protrusion 61 on the pressure plate 6 relative to its corresponding micro light-emitting chip 1. The "preset offset range" is the offset range used to activate the second image recognition unit 912.

[0134] Understandably, in this embodiment, by setting a third image recognition unit 913 and setting the field of view of the third image recognition unit 913 to be greater than the field of view of the second image recognition unit 912, the third image recognition unit 913 can acquire the recognition mark within a larger field of view, avoiding multiple movements of the second image recognition unit 912 or the substrate 2 to ensure that the micro light-emitting chip 1 with the recognition mark is located within the field of view of the second image recognition unit 912.

[0135] Meanwhile, by setting the field of view of the third image recognition unit 913 to be greater than that of the second image recognition unit 912, the displacement error that may exist during multiple movements of the second image recognition unit 912 or the substrate 2 due to the existence of movement accuracy can be avoided. This further improves the alignment accuracy between the bump 61 of the pressure plate 6 and the micro light-emitting chip 1, thereby improving the bonding yield of the micro light-emitting chip 1.

[0136] Furthermore, when the offset S of the protrusion 61 on the pressure plate 6 relative to its corresponding micro-light-emitting chip 1 is within a preset offset range after movement, the second image recognition unit 912 is activated and begins to achieve higher precision alignment between the protrusion 61 and its corresponding micro-light-emitting chip 1, that is, executing step S230b "identifying the protrusion 61 through the first image recognition unit 911 in the image recognition component 91 to obtain the first mark A1, and identifying the micro-light-emitting chip 1 corresponding to the protrusion 61 through the second image recognition unit 912 in the image recognition component 91 to obtain the second mark A2" and step S240b "calculating the offset S12 of the first mark A1 relative to the second mark A2 to obtain the offset S of the protrusion 61 relative to its corresponding micro-light-emitting chip 1".

[0137] By moving the pressure plate 6 so that the offset S of the bump 61 relative to its corresponding micro-light-emitting chip 1 is within a preset offset range, the first image recognition unit 911 and the second image recognition unit 912 can be activated. Through the cooperation of the first image recognition unit 911 and the second image recognition unit 912, precise positioning between the bump 61 and its corresponding micro-light-emitting chip 1 can be achieved. Furthermore, when the offset S between the bump 61 of the pressure plate 6 and its corresponding micro-light-emitting chip 1 is large, the alignment accuracy and efficiency between the bumps 61 on the pressure plate 6 and the micro-light-emitting chip 1 can be improved, thereby improving the bonding effect of the micro-light-emitting chip 1 and increasing the product yield.

[0138] For one embodiment, please refer to Figure 14 , Figure 14 The schematic diagram of the workflow in this embodiment illustrates the process of obtaining the offset S of the pressure plate 6 relative to the micro light-emitting chip 1 in the planar direction of the substrate 2. (See attached diagram.) Figure 14 As shown, step S200, "obtaining the offset S of the pressure plate 6 relative to the micro light-emitting chip 1 in the planar direction of the substrate 2", includes:

[0139] Step S210c: Obtain the offset S of at least two bumps 61 relative to their corresponding micro light-emitting chips 1;

[0140] For details, please refer to Figure 15 , Figure 15 In this embodiment, a schematic diagram of the planar structure is shown to obtain the offset S of the pressure plate 6 relative to the micro light-emitting chip 1 in the planar direction of the substrate 2. (See attached diagram.) Figure 15 As shown, the protrusion 61 on the pressure plate 6 also includes a second protrusion 61b, and the micro light-emitting chip 1 corresponding to the second protrusion 61b is a second micro light-emitting chip 1b.

[0141] Obtain the offset S1a of the first bump 61a relative to the first micro light-emitting chip 1a, and obtain the offset S1b of the second bump 61 relative to the second micro light-emitting chip 1b.

[0142] It should be noted that, in Figure 15 In the illustrated embodiment, the offset of the two protrusions 61 on the pressure plate 6 relative to their corresponding micro-light-emitting chips 1 is only obtained as an example for description and demonstration, and does not represent that in other embodiments of this application, only the offset of the two protrusions 61 relative to their corresponding micro-light-emitting chips 1 can be obtained. In other embodiments of this application, the offset of 3, 4, 5, or other numbers of protrusions 61 relative to their corresponding micro-light-emitting chips 1 can also be obtained.

[0143] Furthermore, in obtaining the offset of at least two bumps 61 relative to their corresponding micro-light-emitting chips 1, the selected position of the bump 61 can be any position of the bump 61 on the pressure plate 6, and is not limited to... Figure 15 The position of the selected bump 61 is shown in the figure.

[0144] Step S220c: Calculate the average of the offsets of at least two bumps 61 relative to their corresponding micro-light-emitting chips 1 to obtain the offset S of the pressure plate 6 relative to the micro-light-emitting chip 1.

[0145] Specifically, such as Figure 15 As shown, the offset S of the pressure plate 6 relative to the micro-light-emitting chip 1 is obtained by calculating the average of the offset S1a of the first bump 61a relative to the first micro-light-emitting chip 1a and the offset S1b of the second bump 61 relative to the second micro-light-emitting chip 1b.

[0146] In other embodiments of this application, the offset S of the pressure plate 6 relative to the micro-light-emitting chip 1 can also be obtained by calculating the variance of the offset of at least two bumps 61 relative to their corresponding micro-light-emitting chips 1.

[0147] In this embodiment, by calculating the average value of the offset of at least two bumps 61 relative to their corresponding micro-light-emitting chips 1, the offset S of the pressure plate 6 relative to the micro-light-emitting chip 1 can be obtained. This can eliminate the situation where the various bumps 61 on the pressure plate 6 cannot be fully aligned with the micro-light-emitting chip 1 due to manufacturing errors that may exist in a single bump 61. This ensures that all the bumps 61 on the pressure plate 6 are fully aligned with the micro-light-emitting chip 1, thereby improving the bonding reliability and bonding effect of the micro-light-emitting chip bonding method of this application.

[0148] One embodiment is also described below. Figure 15 Step S210c, "obtaining the offset S of at least two bumps 61 relative to their corresponding micro-light-emitting chips 1," includes:

[0149] Step S210d: Obtain the offset of at least two bumps 61 relative to their corresponding micro light-emitting chips 1. The bumps 61 are arranged in an array, and the at least two bumps 61 include a first bump 61a and a second bump 61b. The first bump 61a and the second bump 61b are located at the two ends of the diagonal P in the array of bumps 61.

[0150] Specifically, such as Figure 15As shown, the pressure plate 6 has a plurality of protrusions 61 arranged in an array, and the array of protrusions 61 has a diagonal P. The diagonal P is the line connecting the two protrusions 61 with the largest relative distance in the array. In this embodiment, the first protrusion 61a and the second protrusion 61b are located at opposite ends of the diagonal P in the array of protrusions 61.

[0151] Understandably, in this embodiment, by setting the first bump 61a and the second bump 61b to be located at the two ends of the diagonal P of the array of bumps 61, the alignment accuracy between the bumps 61 of the pressure plate 6 and the micro light-emitting chip 1 can be further improved by aligning the two farthest bumps 61 in the array of bumps 61 with their corresponding micro light-emitting chips 1, thereby improving the bonding effect of the micro light-emitting chips.

[0152] Step S300: Move the pressure plate 6 along the axial direction of the bump 61 so that the pin 11 of the micro light-emitting chip 1 contacts and conducts with its corresponding pad 21.

[0153] For details, please refer to Figure 16 , Figure 16 This is a schematic diagram of the structure of the micro LED chip 1 when its pin 11 is in contact with its corresponding pad 21, viewed from one side. Figure 16 As shown, after step S200, "obtaining the offset S of the pressure plate 6 relative to the micro light-emitting chip 1 in the plane direction of the substrate 2, and moving the pressure plate 6 based on the offset S so that the axis of each bump 61 on the pressure plate 6 coincides with the axis of a micro light-emitting chip 1", the axis of each bump 61 on the pressure plate 6 coincides with the axis of a micro light-emitting chip 1.

[0154] The pressure plate 6 is moved along the axial direction of the bump 61 so that the pressure plate 6 moves toward the substrate 2 until each bump 61 on the pressure plate 6 abuts against a micro light-emitting chip 1 and pushes the micro light-emitting chip 1 toward the pad 21, thereby making the pin 11 of the micro light-emitting chip 1 contact and conduct with its corresponding pad 21, achieving the effect of conducting and lighting up the micro light-emitting chip 1.

[0155] Typically, the pressure plate 6 is made of a material with high flatness, such as silicon, to ensure reliable contact and pressing with each micro-light-emitting chip 1. Since the pressure plate is opaque, the existing method of using image sensors to mark alignment through the pressure plate 6 cannot be implemented. This affects the precise alignment between each bump 61 in the pressure plate 6 and its corresponding micro-light-emitting chip 1, resulting in misalignment between the bump 61 and the micro-light-emitting chip 1. Uneven force is applied to the micro-light-emitting chip 1 during pressing, and the pins 11 of the micro-light-emitting chip 1 cannot reliably align with the pads 21 of the substrate 2, reducing the yield rate of the bonded product.

[0156] The micro-light-emitting chip bonding method of this application obtains the offset S of the pressure plate 6 relative to the micro-light-emitting chip 1 in the planar direction of the substrate 2, and moves the pressure plate 6 based on the offset S, so that the axis of each bump 61 on the pressure plate 6 coincides with the axis of a micro-light-emitting chip 1. By moving the pressure plate along the axis of the bump 61, the bump 61 of the pressure plate 6 can abut against the micro-light-emitting chip 1 and push the micro-light-emitting chip 1 towards the substrate 2. At the same time, because the axis of the bump 61 coincides with the axis of the micro-light-emitting chip 1, the force on the micro-light-emitting chip 1 is balanced, and it can move smoothly towards the substrate 2. This allows the pin 11 of the micro-light-emitting chip 1 to reliably contact and conduct with its corresponding pad 21, thereby improving the bonding yield of the micro-light-emitting chip 1.

[0157] In other words, by using the micro-light-emitting chip bonding method of this application, the alignment accuracy between the bumps 61 of the pressure plate 6 and the micro-light-emitting chip 1 can be improved, thereby improving the bonding yield of the micro-light-emitting chip 1.

[0158] This application also provides a micro-light-emitting chip bonding apparatus for executing and implementing the micro-light-emitting chip bonding method in any of the above embodiments. For a detailed structural diagram, please refer to [the specific diagram]. Figure 12 It should be noted that, Figure 12 The micro-light-emitting chip bonding device shown in the embodiments is only an example and does not represent the specific structure of each component of the micro-light-emitting chip bonding device of this application, nor does it represent the specific position of each component in the micro-light-emitting chip bonding device of this application.

[0159] Specifically, the micro-light-emitting chip bonding apparatus of this application includes a stage 5, a pressure plate 6, an image recognition component 91, and a controller (not shown in the figure). The stage 5 is used to support the substrate 2 after mass transfer, wherein multiple pads 21 are arranged in an array on one side surface of the substrate 2, and an adhesive layer 3 is coated between the multiple pads 21, covering the pads 21.

[0160] On the substrate 2 after mass transfer, multiple micro-light-emitting chips 1 are arranged in an array on the side of the adhesive layer 3 away from the pad 21, and the pin 11 of each micro-light-emitting chip 1 corresponds to a pad 21.

[0161] The pressure plate 6 includes a plurality of bumps 61, all of which are disposed facing the substrate 2. The bumps 61 of the pressure plate 6 are arranged in an array, and the orientation and spacing between the bumps 61 in the array correspond to the micro light-emitting chip 1.

[0162] The image recognition component 91 is used to obtain the offset S of the pressure plate 6 relative to the micro light-emitting chip 1 on the substrate 2 in the planar direction of the substrate 2. The image recognition component 91 can be an image sensor CCD.

[0163] The controller is electrically connected to the pressure plate 6 and the image recognition component 91 to realize information transmission with the image recognition component 91, and to control the moving direction and moving distance of the pressure plate 6.

[0164] Specifically, the controller is used to move the pressure plate 6 relative to the micro-light-emitting chip 1 on the substrate 2 in the planar direction of the substrate 2, based on the offset S obtained by the image recognition component 91, so that the axis of each bump 61 on the pressure plate 6 coincides with the axis of a micro-light-emitting chip 1. At the same time, the controller is also used to move the pressure plate 6 along the axial direction of the bump 61 so that the micro-light-emitting chip 1 contacts and conducts electricity with the pad 21 of the substrate 2.

[0165] Understandably, in this embodiment, by setting up the stage 5, the substrate 2 after a massive transfer can be supported, thereby enabling the bonding operation of the micro-light-emitting chip 1 to be completed on the stage 5. By setting up the pressure plate 6 and providing a protrusion 61 on the side of the pressure plate 6 facing the substrate 2, the micro-light-emitting chip 1 can be pushed towards the substrate 2 by the protrusion 61, thereby contacting and conducting with the pads 21 on the substrate 2.

[0166] By setting the image recognition component 91, the offset S of the pressure plate 6 relative to the micro light-emitting chip 1 on the substrate 2 in the plane direction of the substrate 2 can be obtained. By setting the controller, the pressure plate 6 can be moved based on the offset S obtained by the image recognition component 91, so that the axis of each protrusion 61 on the pressure plate 6 coincides with the axis of a micro light-emitting chip 1, so as to ensure the bonding effect between the micro light-emitting chip 1 and the substrate 2.

[0167] By setting a controller, it is also possible to control the movement of the pressure plate 6 in the axial direction of the bump 61, so that the bump 61 of the pressure plate 6 can push the micro light-emitting chip 1 toward the substrate 2.

[0168] Furthermore, the micro-light-emitting chip bonding apparatus of this application can realize and execute the micro-light-emitting chip bonding method described in any of the above embodiments. Simultaneously, because the micro-light-emitting chip bonding apparatus of this application can realize and execute the micro-light-emitting chip bonding method described in any of the above embodiments, the micro-light-emitting chip bonding method of this application possesses all the possible beneficial effects of the micro-light-emitting chip bonding method described in any of the above embodiments.

[0169] It should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0170] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0171] It should be understood that the application of this application 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. Those skilled in the art will understand that implementing all or part of the processes of the above embodiments, and making equivalent changes according to the claims of this invention, still falls within the scope of this invention.

Claims

1. A method for bonding micro light-emitting chips, characterized in that, include: Multiple micro-light-emitting chips are placed on a substrate by mass transfer and fixed with an adhesive layer, wherein the pins of each micro-light-emitting chip are aligned with the pads on the substrate. The offset of the pressure plate relative to the micro light-emitting chip in the planar direction of the substrate is obtained, and the pressure plate is moved based on the offset so that the axis of each protrusion on the pressure plate coincides with the axis of one of the micro light-emitting chips. The pressure plate is moved along the axial direction of the bump so that the pin of the micro light-emitting chip contacts and conducts with the pad aligned with it.

2. The micro-light-emitting chip bonding method according to claim 1, characterized in that, The acquisition of the offset of the pressure plate relative to the micro light-emitting chip in the planar direction of the substrate includes: The first offset of the bump relative to the zero point of displacement is obtained, and the second offset of the micro light-emitting chip corresponding to the bump relative to the zero point of displacement is obtained, wherein the zero point of displacement is a preset reference point on the substrate plane; The offset of the pressure plate relative to the micro light-emitting chip is calculated based on the first offset and the second offset.

3. The micro-light-emitting chip bonding method according to claim 2, characterized in that, The step of obtaining the first offset of the bump relative to the zero point of displacement includes: The pressure plate is moved to obtain a pressing mark of the bump on the imprint plate, wherein the imprint plate is located on one side of the substrate; Obtain the offset of the pressure mark relative to the zero point of displacement to obtain the first offset.

4. The micro-light-emitting chip bonding method according to claim 1, characterized in that, The acquisition of the offset of the pressure plate relative to the micro light-emitting chip in the planar direction of the substrate includes: The offset of the bump relative to the corresponding micro-light-emitting chip is obtained by an image recognition component, thereby obtaining the offset of the pressure plate relative to the micro-light-emitting chip, wherein the image recognition component is located between the pressure plate and the substrate in the direction where the pad and the pin are opposite.

5. The micro-light-emitting chip bonding method according to claim 4, characterized in that, The step of obtaining the offset of the bump relative to its corresponding micro-light-emitting chip through the image recognition component includes: The bump is identified by the first image recognition unit in the image recognition component to obtain a first mark, and the micro light-emitting chip corresponding to the bump is identified by the second image recognition unit in the image recognition component to obtain a second mark; The offset of the first mark relative to the second mark is calculated to obtain the offset of the bump relative to the corresponding micro-light-emitting chip.

6. The micro-light-emitting chip bonding method according to claim 5, characterized in that, Before identifying the bump using the first image recognition unit to obtain the first mark, the process includes: The micro-light-emitting chip corresponding to the bump is identified by a third image recognition unit to obtain an intermediate mark, wherein the field of view of the third image recognition unit is greater than that of the second image recognition unit; Calculate the offset between the intermediate mark and the first mark, and move the pressure plate so that the offset of the bump relative to the corresponding micro light-emitting chip is within a preset offset range.

7. The method for bonding micro-light-emitting chips according to any one of claims 1-6, characterized in that, The acquisition of the offset of the pressure plate relative to the micro light-emitting chip in the planar direction of the substrate includes: The offset of the bump relative to its corresponding micro-light-emitting chip is obtained using a ruler.

8. The method for bonding micro-light-emitting chips according to any one of claims 1-6, characterized in that, The acquisition of the offset of the pressure plate relative to the micro light-emitting chip in the planar direction of the substrate includes: The offset of at least two of the bumps relative to their corresponding micro-light-emitting chips is obtained respectively; Calculate the average of the offsets of the at least two bumps relative to their corresponding micro-light-emitting chips to obtain the offset of the pressure plate relative to the micro-light-emitting chip.

9. The micro-light-emitting chip bonding method according to claim 8, characterized in that, The step of obtaining the offset of at least two of the bumps relative to their corresponding micro-light-emitting chips includes: The offset of at least two of the bumps relative to their corresponding micro light-emitting chips is obtained respectively, wherein the bump array is arranged and the at least two bumps include a first bump and a second bump, the first bump and the second bump are respectively located at the two ends of the diagonal of the bump array.

10. A micro light-emitting chip bonding device, characterized in that, include: A stage, used to support a large number of substrates after transfer; The pressure plate includes a plurality of protrusions, all of which are disposed toward the substrate; An image recognition component is used to obtain the offset of the pressure plate relative to the micro light-emitting chip on the substrate in the planar direction of the substrate; The controller is configured to move the pressure plate based on the offset, such that the axis of each of the bumps on the pressure plate coincides with the axis of one of the micro light-emitting chips; the controller is also configured to move the pressure plate along the axial direction of the bumps, such that the micro light-emitting chip contacts and conducts electricity with the substrate.

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