Laser removal system and method for micro-LED bad chip

Abstract

The invention relates to the technical field of bad chip removal, in particular to a micro-LED bad chip laser removal system and method, which comprises a laser, a beam shaping module, a saddle type integral mirror, a visual processing module and a processing table, and is characterized in that the laser outputs femtosecond laser beams in Gaussian intensity distribution; according to the laser removing system for the Micro-LED bad chip, the light beam shaping module comprises the diaphragm adjusting assembly, the diaphragm adjusting assembly is located behind the laser device, and the saddle-shaped integral mirrors are arranged behind the light beam shaping module at intervals, so that the shaped rectangular light beams are subjected to energy and shape distribution regulation and control to form the light spots; therefore, the shape, size and energy distribution of the femtosecond laser beam are dynamically adjusted through the beam shaping module and the saddle-shaped integral mirror, so that the femtosecond laser beam can be dynamically adjusted to remove the defective chip.

Description

Technical Field

[0001] This invention relates to the technical field of defective chip removal, and more particularly to a laser removal system and method for defective Micro-LED chips. Background Technology

[0002] Micro-LED refers to a display technology that uses a high-density integrated array of three-color LED chips with a size of less than 50μm. It boasts advantages such as high brightness, high contrast ratio, high resolution, fast response, and low energy consumption, and has broad application prospects in large-screen displays, AR / VR near-eye displays, and flexible displays. It is considered by the industry to be a major development direction for next-generation display technologies. However, the Micro-LED manufacturing process is complex, involving numerous steps in panel manufacturing. Especially under the influence of factors such as materials, equipment, and environment, defects are inevitably generated throughout the manufacturing process, making it difficult to guarantee the quality of the panel-level Micro-LED display panel and resulting in high production costs. Therefore, repairing defective Micro-LED chips is a crucial step in Micro-LED display panel production and an essential process for improving the overall yield of Micro-LED displays.

[0003] In the prior art, patent number CN117884757A discloses a defective chip repair device and method based on femtosecond laser. The device includes a laser preprocessing module, a beam shaping module, a mirror module, a visualization processing module, an auxiliary processing module, a position synchronization output module, and an industrial control computer module. The method includes: outputting a matrix beam; fixing the defective chip on a processing table and focusing the matrix beam onto the surface of the defective chip; blowing air onto the defective chip through an auxiliary air tube; setting the processing objective to a low-magnification processing mirror and homing the scanning galvanometer; executing a defective chip removal command; determining whether the defective chip has been removed through an identification and monitoring module; and executing a pad cleaning command to complete the repair. This invention can achieve integrated processing of chip removal and pad cleaning, as well as repair of faulty chips generated during the transfer process, but it cannot adjust the beam size to adapt to the removal of different chip models.

[0004] Patent CN113770515B discloses a method and application for resetting the coupling coefficient of a directional coupler using a femtosecond laser secondary direct writing technique. This method, belonging to the field of laser processing technology, includes cleaning the glass sample; constructing the laser processing optical path and leveling the sample to be processed; and performing a second femtosecond laser direct writing of the device. The process involves first closing the shutter and moving the glass sample to the starting processing position; then rotating the half-wave plate and adjusting the laser power; finally, the control software directly runs a pre-written processing program, performing secondary direct writing in the processing areas of the two waveguides in the coupling region; after processing, the sample is polished to obtain two new waveguides with different coupling spacings from the original waveguides; the processing area is within a region 0μm-3μm above and below the central axis of the original waveguides. While this method can restore and redistribute the initial beam splitting ratio of the directional coupler, it cannot address the issue of controlling the shape and energy distribution of the laser beam to adapt to the removal requirements of different chip models. Summary of the Invention

[0005] The first objective of this invention is to provide a laser removal system for defective Micro-LED chips, which aims to solve the problems of morphology and energy regulation distribution in chip removal by femtosecond laser beams.

[0006] To address the aforementioned technical problems, a laser removal system for defective Micro-LED chips is provided, comprising a laser, a beam shaping module, a saddle-shaped integrating mirror, a visualization processing module, and a processing stage. The laser outputs a femtosecond laser beam with a Gaussian intensity distribution. The beam shaping module includes an aperture adjustment assembly, a...

[0007] The system includes a first lens and a second lens. The aperture adjustment assembly is located behind the laser and adjusts the shape and size of the femtosecond laser beam and filters out the low-energy region at the edge of the Gaussian beam. The first lens and the second lens are spaced apart behind the aperture adjustment assembly, and both the first lens and the second lens are used to adjust and homogenize the energy of the femtosecond laser beam so that the femtosecond laser beam is shaped into a rectangular beam. The saddle-shaped integrating mirror is spaced behind the beam shaping module to change the transmission direction of the rectangular beam and to control the energy and shape distribution of the shaped rectangular beam to form a light spot. The processing stage is placed perpendicular to the horizontal plane and moves by sliding guide rails to adsorb or clamp the substrate to be processed.

[0008] Further, the aperture adjustment assembly includes a first aperture, a second aperture, a third aperture, a fourth aperture, and a driving element. The first, second, third, and fourth apertures are arranged in a vortex pattern, and each aperture is provided with a guiding mechanism. The driving element drives each aperture to move on the guiding mechanism. The first aperture is parallel to the third aperture, and the second aperture is parallel to the fourth aperture. The first aperture and the third aperture move away from each other through the driving element, and the second aperture and the fourth aperture move away from each other through the driving element, so that the center of the generated rectangular beam does not deviate from the center of the femtosecond laser beam; the first aperture...

[0009] A first aperture is perpendicular to the second aperture, and a third aperture is perpendicular to the fourth aperture. When the first aperture and the second aperture move perpendicularly relative to each other, and the third aperture and the fourth aperture move perpendicularly relative to each other, the length and width range of the rectangular beam are adjusted.

[0010] Furthermore, the incident light spot intensity distribution function of the beam shaping module is Iin(r,θ), and the output rectangular light spot intensity distribution is I... out =rect(x / 2u, y / 2v), the total energy of the two is equal:

[0011]

[0012] Where r and θ are the polar coordinates of the incident surface, R is the beam radius, u and v are the side lengths of the exit rectangular spot, and x and y are the coordinates of the output surface.

[0013] Furthermore, the saddle-shaped integrating mirror is symmetrically composed of a first half-integrating mirror and a second half-integrating mirror, with the first half-integrating mirror forming a first integrating surface and the second half-integrating mirror forming a second integrating surface. An axis is formed at the intersection of the first integrating surface and the second integrating surface. The first integrating surface and the second integrating surface can rotate relative to the axis to shape and control the rectangular beam to form the light spot.

[0014] Furthermore, the rotation angle between the first integrating surface and the second integrating surface on the saddle-shaped integrating mirror is θ. When the first integrating surface and the second integrating surface rotate, they form a dynamic optical path, and the radius of gyration of the dynamic optical path is h.

[0015]

[0016] Among them, f w The working distance of the saddle-shaped integrating mirror is given by D, where D is the farthest distance between the first and second integrating surfaces, and a is the working distance of the integrating mirror. w denoted as the superposition length within the light spot, and 'a' as the length of the light spot.

[0017] Furthermore, the visualization processing module includes a scanning galvanometer, a field lens, a second reflecting mirror, a processing objective lens, a recognition and monitoring module, a camera, a beam splitter, and a light source. The scanning galvanometer is used to receive the light spot formed by the saddle-shaped integrating mirror and quickly scan it to the field lens. The second reflecting mirror is located between the field lens and the processing objective lens to reflect the light spot from the field lens to the processing objective lens. The processing objective lens focuses the light spot onto the substrate to be processed. The beam splitter faces the substrate to be processed. The light source illuminates the substrate to be processed through the beam splitter. The camera is located on one side of the beam splitter and is used to acquire the focal image of the substrate to be processed in real time and upload the acquired focal image information to the recognition and monitoring module.

[0018] Furthermore, the laser removal system for defective Micro-LED chips also includes a laser power attenuator, a beam expander, and a first reflector. The laser power attenuator is located between the laser and the beam shaping module, and attenuates the laser emitted by the laser to make the energy density of the laser beam suitable for the removal or cleaning stage. The beam expander is located between the laser power attenuator and the beam shaping module, and is used to expand the femtosecond laser beam with a Gaussian intensity distribution. The first reflector is located between the saddle-shaped integrating mirror and the visualization processing module, and is used to reflect the light spot generated by the saddle-shaped integrating mirror into the visualization processing module.

[0019] The laser removal system for defective Micro-LED chips also includes a position synchronization module, an industrial computer, and an auxiliary air pipe. The position synchronization module is used to keep the output spacing of the laser constant, and the auxiliary air pipe is used to blow auxiliary gas into the laser focusing area of ​​the substrate to be processed. The industrial computer is connected to the laser power attenuator, the visualization processing module, the position synchronization module, and the processing table.

[0020] The second objective of this invention is to provide a laser removal system for defective Micro-LED chips, which aims to solve the problem of identifying chips that can be accurately removed by femtosecond laser beams.

[0021] To solve the above-mentioned technical problems, a laser removal method for defective Micro-LED chips is provided, applied to the aforementioned laser removal system for defective Micro-LED chips, comprising the following steps:

[0022] S1. Fix the substrate to be processed on the processing table. The industrial control computer reads the CAD drawing with the marked defective chip positions, addresses by calibrating the Mark points, and focuses and aligns the camera with the center position of the defective chip.

[0023] S2. Select a low-magnification processing objective lens, adjust the spot size to the chip size through the beam shaping module, and use the saddle-shaped integrating mirror to control the energy and shape distribution of the shaped rectangular beam to form a spot. The scanning galvanometer returns to zero, and the chip removal command is executed according to the set laser parameters.

[0024] S3. The camera identifies image information indicating whether the defective chip on the pad of the substrate to be processed has been completely removed. The identification and monitoring module analyzes the image information. If the analysis shows that the defective chip on the pad of the substrate to be processed has been completely removed, then step S5 is executed; if the analysis shows that the defective chip on the pad of the substrate to be processed has not been completely removed, then step S4 is executed.

[0025] S4. Based on the situation where the defective chip has not been completely removed, the energy distribution of the rectangular beam is dynamically adjusted by the aperture adjustment component and the saddle-shaped integrating mirror to form a new light spot. The chip removal command is executed again, and then the image information of whether the defective chip has been completely removed is identified. If it is found that the defective chip on the pad of the substrate to be processed has not been completely removed, step S4 is repeated.

[0026] S5. The processing objective lens is switched to a high-magnification processing lens, and the visualization processing module compensates to the focal position according to the stored position, and reduces the laser energy density to the set value through the laser power attenuator.

[0027] S6. Execute the pad cleaning command according to the set scanning trajectory, scanning interval, line spacing and laser parameters.

[0028] Further, in step S2, the laser parameters set are as follows: the pulse width of the femtosecond laser is 200fs to 600fs, the focusing energy density is 0.6J / cm2 to 40J / cm2, the laser scanning spacing is 0.5μm to 5μm, the laser scanning line spacing is 2μm to 10μm, the scanning speed is 1mm / s to 200mm / s, and the repetition frequency is 1100KHZ to 1500KHZ.

[0029] Further, in step S2, the preset spot size is the chip size: the chip size is 25μm to 30μm in length, 10μm to 15μm in width, and 4μm to 8μm in height.

[0030] Implementing the embodiments of the present invention will have the following beneficial effects:

[0031] 1. The laser removal system for defective Micro-LED chips in this embodiment includes a beam shaping module comprising an aperture adjustment component, a first lens, and a second lens. The aperture adjustment component is located behind the laser, and the first and second lenses are spaced behind the aperture adjustment component. Both the first and second lenses are used to adjust and homogenize the energy of the femtosecond laser beam. A saddle-shaped integrating mirror is spaced behind the beam shaping module to control the energy and shape distribution of the shaped rectangular beam to form a light spot. Thus, the shape, size, and energy distribution of the femtosecond laser beam are dynamically adjusted through the beam shaping module and the saddle-shaped integrating mirror, thereby enabling the femtosecond laser beam to be dynamically adjusted to remove defective chips. This overcomes the limitations of existing technologies where the size of the femtosecond laser beam cannot be dynamically adjusted to adapt to the removal of different chip models.

[0032] 2. In this embodiment, the laser removal system for defective Micro-LED chips can adapt to the energy distribution control of femtosecond laser beams after the saddle-shaped integrating mirrors are spaced behind the beam shaping module to change the transmission direction of the rectangular beam and to control the energy and shape distribution of the shaped rectangular beam to form a light spot.

[0033] 3. The laser removal system for defective Micro-LED chips in this embodiment includes a first aperture, a second aperture, a third aperture, a fourth aperture, and a driving element. The first, second, third, and fourth apertures are arranged in a vortex pattern, and each aperture is provided with a guiding mechanism. The driving element drives each aperture to move on the guiding mechanism. The first and third apertures are parallel, and the second and fourth apertures are parallel. Thus, the first and third apertures can move away from each other through the driving element, and the second and fourth apertures can move away from each other through the driving element, thereby adjusting the shape of the rectangular beam and controlling the relative position between the center of the rectangular beam and the center of the femtosecond laser beam.

[0034] 4. In the laser removal system for defective Micro-LED chips in this embodiment, the saddle-shaped integrating mirror is symmetrically composed of a first half-integrating mirror and a second half-integrating mirror. The first half-integrating mirror forms a first integrating surface and the second half-integrating mirror forms a second integrating surface. An axis is formed at the intersection of the first integrating surface and the second integrating surface. Thus, when the first integrating surface and the second integrating surface rotate relative to the axis, the rectangular beam is shaped and controlled to form light spots with different shapes and energy distributions.

[0035] 5. The laser removal method for defective Micro-LED chips in this embodiment involves fixing the substrate to be processed on the processing table. The industrial control computer reads the CAD drawing with the marked defective chip locations, addresses the marks, and focuses the camera to align with the center of the defective chip. A low-magnification processing lens is selected as the processing objective. The beam shaping module adjusts the spot size to the chip size. The saddle-shaped integrating mirror controls the energy and shape distribution of the shaped rectangular beam to form a spot. The scanning galvanometer returns to zero, and the chip removal command is executed according to the set laser parameters. The camera identifies image information indicating whether the defective chip on the substrate pads has been completely removed. The monitoring module analyzes the image information. Based on the incomplete removal of defective chips, it dynamically adjusts the energy distribution of the rectangular beam using the aperture adjustment component and the saddle-shaped integrating mirror to form a new light spot. It then executes the chip removal command again and retrieves the image information regarding whether the defective chip has been completely removed. The processing objective is switched to a high-magnification processing lens, and the visualization processing module compensates for the focal position based on the stored location. The laser energy density is reduced to a set value using a laser power attenuator. Based on the set scanning trajectory, scanning interval, line spacing, and laser parameters, the pad cleaning command is executed. This allows for real-time control of the energy distribution and shape of the femtosecond laser beam based on feedback, thereby accurately and efficiently removing defective chips.

[0036] 6. The laser removal method for defective Micro-LED chips in this embodiment achieves integrated processing of chip removal and pad cleaning by switching between large and small light spots; the beam shaping module and saddle-shaped integrating mirror are used to shape and control the light spot, and the defective chip is peeled off by two irradiations, which improves processing efficiency; vertical surface processing, under the action of gravity and with the help of an auxiliary gas device, can blow 99% of the debris away from the processing table, effectively avoiding contamination of the processing area and improving the cleanliness of the processing area. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the laser removal system described in Embodiment 1 of the present invention;

[0039] Figure 2 This is a schematic diagram of the aperture adjustment assembly described in Embodiment 1 of the present invention;

[0040] Figure 3This is a schematic diagram of the saddle-shaped integrating mirror described in Embodiment 1 of the present invention;

[0041] Figure 4 This is the optical path diagram of the rotating mirror surface of the saddle-shaped integrating mirror according to Embodiment 1 of the present invention;

[0042] Figure 5 for Figure 4 Analysis of light spots at different defocus distances;

[0043] Figure 6 The rectangular light spot shaped by the beam shaping module described in Embodiment 1 of the present invention;

[0044] Figure 7 for Figure 6 Energy distribution diagram of a rectangular light spot;

[0045] Figure 8 This is a schematic diagram of the laser removal method for defective Micro-LED chips according to Embodiment 2 of the present invention;

[0046] Figure 9 This is a flowchart of the laser removal method for defective Micro-LED chips according to Embodiment 2 of the present invention.

[0047] Wherein: 100, laser removal system; 110, laser; 120, beam shaping module; 121, aperture adjustment assembly; 1211, first aperture; 1212, second aperture; 1213, third aperture; 1214, fourth aperture; 1215, driving element; 122, first lens; 123, second lens; 130, saddle-shaped integrating mirror; 131, first half-integrating mirror; 1311, first integrating surface; 132, second half-integrating mirror; 13 21. Second integrating surface; 1301. Axis; 140. Visual processing module; 141. Scanning galvanometer; 142. Field lens; 143. Second reflecting mirror; 144. Processing objective lens; 145. Identification and monitoring module; 146. Camera; 147. Beam splitter prism; 148. Light source; 150. Processing stage; 160. Optical power attenuator; 170. Beam expander; 180. First reflecting mirror; 190. Position synchronization module; 200. Industrial computer; 210. Auxiliary air tube. Detailed Implementation

[0048] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0049] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0050] 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 invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0051] Example 1

[0052] Please refer to Figures 1-7This invention provides a laser removal system 100 for defective Micro-LED chips. The system includes a laser 110, a beam shaping module 120, a saddle-shaped integrating mirror 130, a visualization processing module 140, and a processing table 150. The laser 110 outputs a femtosecond laser beam with a Gaussian intensity distribution. The beam shaping module 120 includes an aperture adjustment component 121, a first lens 122, and a second lens 123. The aperture adjustment component 121 is located behind the laser 110 and is used to adjust the shape and size of the femtosecond laser beam while filtering out low-energy regions at the edge of the Gaussian beam. The first lens 122 and the second lens 123 are positioned behind the aperture adjustment component 121, and both are used to adjust and homogenize the energy of the femtosecond laser beam to shape it into a rectangular beam. The saddle-shaped integrating mirror 130... A zero-interval beam is positioned behind the beam shaping module 120 to change the transmission direction of the rectangular beam and to control the energy and shape distribution of the shaped rectangular beam to form a light spot. The visualization processing module 140 receives the light spot output by the saddle-shaped integrating mirror 130 and moves along the sliding guide rail in the X-axis direction to focus the light spot on the substrate to be processed. The processing stage 150 is placed perpendicular to the horizontal plane and moves along the sliding guide rail in the Y and Z-axis directions to adsorb or clamp the substrate to be processed. When the rectangular beam size of the femtosecond laser beam adjusted by the aperture adjustment component 121 gradually decreases, the center distance of the double rectangular beam light spot shaped by the saddle-shaped integrating mirror 130 dynamically decreases. When the rectangular beam size of the femtosecond laser beam adjusted by the aperture adjustment component 121 gradually increases, the center distance of the double rectangular beam light spot shaped by the saddle-shaped integrating mirror 130 dynamically increases, so that the energy and shape of the light spot are dynamically adjusted to remove defective chips of different types. In specific applications, laser 110 is mainly used to output a femtosecond laser beam with a Gaussian intensity distribution of 343nm-365nm, and beam shaping module 120 is mainly used to shape a standard Gaussian beam into a rectangular beam with uniform energy distribution.

[0053] The beam shaping module shapes beam 120 as follows: the Gaussian beam from the incident module is adjusted in shape and size by the aperture adjustment component 121, while the low-energy region at the edge of the Gaussian beam is filtered out. After passing through the first lens 122 and the second lens 123 to homogenize the laser energy, the Gaussian beam is shaped into a rectangular beam. The shaped rectangular beam has a uniform energy distribution, as shown in the image. Figure 6 As shown, the energy distribution diagram of the output rectangular light spot is shown below. Figure 7 The module is characterized by an incident light spot intensity distribution function of Iin(r,θ) and an outgoing rectangular light spot intensity distribution function of Iin(r,θ).

[0054] I out=rect(x / 2u, y / 2v), the total energy of the two is equal: Where r and θ are the polar coordinates of the incident surface, R is the beam radius, u and v are the side lengths of the exit rectangular spot, and x and y are the coordinates of the output surface.

[0055] In addition, the saddle-shaped integrating mirror 130 is used to change the laser transmission direction and to control the energy and shape distribution of the light spot after it is shaped by the beam shaping module 120. Then, the visualization processing module 140 is used to receive the light spot output by the saddle-shaped integrating mirror 130. The visualization processing module 140 moves along the sliding guide rail in the X-axis direction so that the light spot is focused on the substrate to be processed. The processing stage 150 is placed perpendicular to the horizontal plane and moves in the Y and Z-axis directions through the sliding guide rail. It is used to adsorb or clamp the substrate to be processed so that the femtosecond laser beam can remove defective chips in batches.

[0056] In one possible implementation, the aperture adjustment assembly 121 includes a first aperture 1211, a second aperture 1212, a third aperture 1213, a fourth aperture 1214, and a driving element 1215. The first aperture 1211, the second aperture 1212, the third aperture 1213, and the fourth aperture 1214 are arranged in a vortex shape. Each aperture is provided with a guiding mechanism. The driving element 1215 drives each aperture to move on the guiding mechanism. The first aperture 1211 is parallel to the third aperture 1213, the second aperture 1212 is parallel to the fourth aperture 1214, and the first aperture 1211 and the third aperture 1213 move away from each other through the driving element 1215. The second aperture 1212 and the fourth aperture 1214 also move away from each other through the driving element 1215, so as to adjust the shape of the rectangular beam and control the relative position of the center of the rectangular beam and the center of the femtosecond laser beam. In specific applications, the aperture adjustment assembly 121 mainly consists of four light-blocking apertures and a driving element 1215 (not shown in the figure). The four apertures are arranged in a vortex shape, and each aperture has a guiding mechanism and is driven by an independent electromagnetic linear driving element 1215 to move in the guiding direction of the guiding mechanism. The driving units of the parallel first aperture 1211 and the third aperture 1213 (or the second aperture 1212 and the fourth aperture 1214) will simultaneously drive the apertures in opposite directions to ensure that the center of the rectangle does not deviate from the center of the laser beam. It is worth noting that when the driving units of the parallel first aperture 1211 and the third aperture 1213 (or the second aperture 1212 and the fourth aperture 1214) drive the apertures in opposite directions asynchronously, on the one hand, the center position of the rectangle can be changed, and on the other hand, the rectangular beam can be irregularly deformed or made into a rhombus or square shape to adapt to different chip types.

[0057] In one possible implementation, the first aperture 1211 is perpendicular to the second aperture 1212, and the third aperture 1213 is perpendicular to the fourth aperture 1214. When there is a vertical relative movement between the first aperture 1211 and the second aperture 1212, and between the third aperture 1213 and the fourth aperture 1214, the length and width range of the rectangular beam can be adjusted. In specific applications, since the first aperture 1211 is perpendicular to the second aperture 1212, and the third aperture 1213 is perpendicular to the fourth aperture 1214, when there is a vertical relative movement between the first aperture 1211 and the second aperture 1212, and between the third aperture 1213 and the fourth aperture 1214, the length and width of the rectangular beam can be changed by driving the two sets of mutually perpendicular apertures.

[0058] In one possible implementation, the saddle-shaped integrating mirror 130 is symmetrically composed of a first half-integrating mirror 131 and a second half-integrating mirror 132. The first half-integrating mirror 131 forms a first integrating surface 1311 and the second half-integrating mirror 132 forms a second integrating surface 1321. An axis 1301 is formed at the junction of the first integrating surface 1311 and the second integrating surface 1321. The first integrating surface 1311 and the second integrating surface 1321 can rotate relative to the axis 1301 to shape and control the rectangular beam to form a light spot. In practical applications, the saddle-shaped integrating mirror 130, based on a traditional integrating mirror, symmetrically divides its surface along the central axis 1301 into a first half-integrating mirror 131 and a second half-integrating mirror 132. The first half-integrating mirror 131 forms a first integrating surface 1311, and the second half-integrating mirror 132 forms a second integrating surface 1321. The intersection of the first integrating surface 1311 and the second integrating surface 1321 forms the axis 1301. The first integrating surface 1311 and the second integrating surface 1321 can rotate relative to the axis 1301, respectively. The optical path diagram changes as follows: Figure 4 As shown, the saddle-shaped integrating mirror has a working distance f of 130. w Given a radius of gyration h and a maximum distance D, the focal points of the two half-mirror paths are separated by a certain distance. By rotating the first half-integral mirror 131 and the second half-integral mirror 132, the higher energy portion in the center is reflected to the outside of the light spot, while the originally weaker energy portion at the edge is reflected to the center of the saddle-shaped light spot. The superposition length inside the light spot is a. w Finally, a saddle-shaped distribution of light spot length *a* with low energy in the middle and high energy at both ends is obtained. The rotation angle θ of the first integrating surface 1311 and the second integrating surface 1321 on the saddle-shaped integrating mirror 130 can be calculated from the desired saddle-shaped direction length *a* of the light spot. The radius of gyration h of the optical path is calculated as follows: Figure 5The image shows the laser spot analysis diagram after reflection by the saddle-shaped integrating mirror 130 at different defocus distances. As the defocus distance decreases, the energy and shape of the laser spot will gradually spread to both sides. The defocus distance is, for example, 0 μm at the focal point, +100 μm 100 μm above the focal point, and -100 μm 100 μm below the focal point.

[0059] In one possible implementation, when the rectangular beam size of the femtosecond laser beam, adjusted by the aperture adjustment assembly 121 through vertically opposing movements between the first aperture 1211 and the second aperture 1212, and vertically opposing movements between the third aperture 1213 and the fourth aperture 1214, gradually decreases, the center distance of the double rectangular beam spot shaped by the saddle-shaped integrating mirror 130 is dynamically reduced by forward rotation of the first half-integrating mirror 131 and the second half-integrating mirror 132; when the rectangular beam size of the femtosecond laser beam, adjusted by the aperture adjustment assembly 121 through vertically opposing movements between the first aperture 1211 and the second aperture 1212, and vertically opposing movements between the third aperture 1213 and the fourth aperture 1214, gradually increases, the center distance of the double rectangular beam spot shaped by the saddle-shaped integrating mirror 130 is dynamically increased by reverse rotation of the first half-integrating mirror 131 and the second half-integrating mirror 132, so that the energy and shape of the beam spot are dynamically adjusted to remove defective chips of different types.

[0060] In one possible implementation, the visualization processing module 140 includes a scanning galvanometer 141, a field lens 142, a second reflecting mirror 143, a processing objective lens 144, an identification and monitoring module 145, a camera 146, a beam splitter 147, and a light source 148. The scanning galvanometer 141 is used to receive the light spot formed by the saddle-shaped integrating mirror 130 and quickly scan it to the field lens 142. The second reflecting mirror 143 is located between the field lens 142 and the processing objective lens 144 to reflect the light spot from the field lens 142 to the processing objective lens 144. The processing objective lens 144 focuses the light spot onto the substrate to be processed. The beam splitter 147 faces the substrate to be processed. The light source 148 illuminates the substrate to be processed through the beam splitter 147. The camera 146 is located on one side of the beam splitter 147 and is used to acquire the focal image of the substrate to be processed in real time and upload the acquired focal image information to the identification and monitoring module 145. In practical applications, the visualization processing module 140 can move along the sliding guide rail in the X-axis direction to focus the sample; the scanning galvanometer 141 drives the mirrors on both axes to tilt due to the high-speed rotation of the motor, and the femtosecond laser beam enters the field lens 142 for two-dimensional high-speed scanning in the horizontal plane; the second reflecting mirror 143 is used to change the laser transmission direction, and the laser beam after changing the transmission direction enters the processing objective lens 144, which can be switched between low-magnification and high-magnification processing lenses, and the low-magnification and high-magnification processing lenses can be switched in the Z-axis direction via the sliding guide rail. When focusing with the low-magnification processing lens, a rectangular light spot with uniform energy distribution of the same size as the LED chip is obtained. Different energy distributions can be selected by adjusting the working distance. When focusing with the high-magnification processing lens, a smaller rectangular light spot with uniform energy distribution is obtained; the beam splitter prism 147 is mainly used for beam splitting; the light source 148 is mainly used to provide light source 148 for the processing area of ​​the substrate to be processed. Camera 146 is mainly used for real-time image acquisition. The focus of camera 146 and the focus of low-magnification and high-magnification processing lenses are calibrated and compensated respectively so that the clear position of camera 146 is the focus position of processing. The identification and monitoring module 145 mainly identifies and analyzes the processing area image acquired in real time by camera 146 to determine whether the processing effect meets the requirements. This module can be trained and calibrated according to the design layout of different samples.

[0061] In one possible implementation, the laser removal system 100 for defective Micro-LED chips further includes a laser power attenuator 160, a beam expander 170, and a first reflector 180. The laser power attenuator 160 is located between the laser 110 and the beam shaping module 120, and attenuates the laser emitted from the laser 110 to make the energy density of the laser beam suitable for the removal or cleaning stage. The beam expander 170 is located between the laser power attenuator 160 and the beam shaping module 120, and is used to expand the femtosecond laser beam with a Gaussian intensity distribution. The first reflector 180 is located between the saddle-shaped integrating mirror 130 and the visualization processing module 140, and is used to reflect the light spot generated by the saddle-shaped integrating mirror 130 into the visualization processing module 140. In specific applications, the laser power attenuator 160 mainly attenuates the laser emitted from the laser 110 to make its energy density suitable for the removal or cleaning process. The beam expander 170 expands the laser beam with a Gaussian intensity distribution to a suitable size. The first reflector 180 is used to change the laser transmission direction, and the beam after changing the transmission direction enters the visualization processing module 140.

[0062] In one possible implementation, the laser removal system 100 for defective Micro-LED chips further includes a position synchronization module 190, an industrial computer 200, and an auxiliary air pipe 210. The position synchronization module 190 is used to maintain a constant output spacing of the laser 110, and the auxiliary air pipe 210 is used to blow auxiliary gas into the laser focusing area of ​​the substrate to be processed. The industrial computer 200 is electrically connected to the laser power attenuator 160, the visualization processing module 140, the position synchronization module 190, and the processing table 150. In specific applications, the position synchronization module 190, also known as PSO, is mainly used to control the laser output spacing to remain constant during high-speed laser scanning. The industrial control computer 200 is mainly used to control the laser 110, laser power attenuator 160, visualization processing module 140, position synchronization output module, and processing table 150. The industrial control computer 200 controls the laser 110, including laser output, coordination between the laser position synchronization output module and the galvanometer scanning speed, etc.; controls the laser power attenuator 160, including increasing or decreasing power when switching between low-magnification and high-magnification processing lenses, etc.; controls the visualization processing module 140, including galvanometer scanning parameters, switching between low-magnification and high-magnification lenses, module movement in the X-axis direction, and intensity adjustment of the light source 148, etc.; controls the processing table 150, including platform movement in the Y and Z axes, and vacuum adsorption of the platform, etc. The auxiliary gas tube 210 mainly functions in the laser focusing area, blowing auxiliary gas from top to bottom in the 0-180° range to prevent processing debris from falling onto the substrate and causing secondary pollution.

[0063] The working principle of the laser removal system 100 for defective Micro-LED chips is as follows: A femtosecond laser is used as the processing light source 148. The femtosecond laser emitted from the femtosecond laser source 148 is modulated by the beam shaping module 120, and the Gaussian beam is converted into a rectangular beam with uniform energy distribution. The length and width of the rectangle are adjustable. The saddle-shaped integrating mirror 130 regulates the uniform spot energy distribution. By controlling the switching of the laser power attenuator 160 and the processing objective lens 144, the LED chip can be processed with a large spot using a low-magnification processing lens at a higher power, and the pads can be cleaned with a small spot using a high-magnification processing lens at a lower power. The laser emitted from the processing objective lens 144 is horizontal. The processing stage 150 is perpendicular to the laser. The substrate to be processed is fixed by vacuum adsorption or clamping. The vertical processing stage 150, together with the auxiliary gas blown out by the auxiliary air tube 210, can blow more than 99% of the debris generated during the processing away from the processing area, effectively avoiding secondary pollution caused by debris falling onto the substrate during processing by the traditional horizontal processing stage 150.

[0064] Example 2

[0065] This embodiment differs from the subject matter protected in Embodiment 1, specifically in the following ways:

[0066] Please refer to Figure 8 and Figure 9 To solve the above-mentioned technical problems, a laser removal method for defective Micro-LED chips is provided, applied to the aforementioned laser removal system 100 for defective Micro-LED chips, comprising the following steps:

[0067] S1. Fix the substrate to be processed on the processing table 150. The industrial control computer 200 reads the CAD drawing with the marked defective chip positions, addresses by calibrating the Mark points, and the camera 146 focuses and aligns with the center position of the defective chip.

[0068] S2. Select the processing objective lens 144 as a low-magnification processing lens, adjust the spot size to the chip size through the beam shaping module 120, and use the saddle-shaped integrating mirror 130 to control the energy and shape distribution of the shaped rectangular beam to form a spot. The scanning galvanometer 141 returns to zero, and executes the chip removal command according to the set laser parameters.

[0069] S3. The camera 146 identifies the image information of whether the defective chip on the pad of the substrate to be processed has been completely removed. The identification and monitoring module 145 analyzes the image information. If the analysis shows that the defective chip on the pad of the substrate to be processed has been completely removed, then step S5 is executed; if the analysis shows that the defective chip on the pad of the substrate to be processed has not been completely removed, then step S4 is executed.

[0070] S4. Based on the situation where the defective chip has not been completely removed, the energy distribution of the rectangular beam is dynamically adjusted by the aperture adjustment component 121 and the saddle-shaped integrating mirror 130 to form a new light spot. The chip removal command is executed again. Then, the image information of whether the defective chip has been completely removed is identified. If it is found that the defective chip on the pad of the substrate to be processed has not been completely removed, step S4 is repeated.

[0071] S5. The processing objective lens 144 is switched to a high-magnification processing lens. The visualization processing module 140 compensates to the focal position according to the stored position and reduces the laser energy density to the set value through the laser power attenuator 160.

[0072] S6. Execute the pad cleaning command according to the set scanning trajectory, scanning interval, line spacing, and laser parameters. In a specific application, the sample in this embodiment is a GaN-based micro-LED chip with a size of 30μm*15μm. First, the sample is placed on the processing stage 150 by vacuum adsorption. The industrial control computer 200 reads the CAD drawing with the marked defective chip location, and the camera 146 focuses and aligns with the center position of the defective chip through the calibrated Mark point address. Assist gas is turned on and blown into the processing area through the assist gas pipe 210. The adjustment knob on the aperture adjustment assembly 121 is rotated to adjust the aperture parameters and the saddle-shaped integrating mirror 130 is rotated to 5. The processing objective lens 144 is switched to a low-magnification processing lens. The parameters of the laser 110, laser power attenuator 160, and beam shaping module 120 are set. The parameters were set such that the laser single-pulse energy density was 34 J / cm², the repetition frequency was 1000 kHz, and the scan was performed once. The focal plane spot size of the low-magnification processing mirror was 30 μm * 15 μm. To execute the chip removal command, the chip was first irradiated twice at a higher power using a large spot of the same size as the chip. The first irradiation was at a positive defocus of +100°, resulting in a narrow rectangular spot. During irradiation, ionization and thermal ablation occurred on the chip surface, and the chip interior was also torn due to thermal stress. The second irradiation was performed at a negative defocus of -50°, resulting in a double rectangular spot. This irradiated the weaker ends of the chip connections. Mechanical ablation was used to peel the torn chip from the pads, and large chip debris was blown away by auxiliary gas. The sample is then processed; the processed image is acquired in real time by camera 146 and analyzed by identification and monitoring module 145 to determine whether the chip has been completely removed. If the result is "no", the energy distribution of the rectangular beam is dynamically adjusted by aperture adjustment component 121 and saddle-shaped integrating mirror 130 to form a new light spot based on the situation where the defective chip has not been completely removed. The chip removal command is executed again, and the image information of whether the defective chip has been completely removed is identified. If the analysis shows that the defective chip on the pad of the substrate to be processed has not been completely removed, this step is repeated. When local residue is not removed during chip removal, such as residue on one side or in a local area of ​​the chip, it can be removed by aperture adjustment component 121 and... The saddle-shaped integrating mirror 130 dynamically adjusts the energy distribution of the rectangular beam to form a new spot, focusing on improving the laser energy distribution for removal. After the chip is completely peeled off from the pads, the scanning path of the scanning galvanometer 141 is controlled by the industrial control computer 200. d1 is the PSO-controlled spot spacing, and d2 is the filling scanning spacing. The specific values ​​of d1 and d2 are 3μm and 6μm, respectively. d1 and d2 depend on the small spot size used to clean the pads. The scanning center point area (based on the center of the field of view of the camera 146) is 54μm*30μm. The processing mirror is switched to a high-magnification processing mirror. The position conversion compensation between the low-magnification and high-magnification processing mirrors is corrected and stored by the industrial control computer 200.The parameters of the laser 110, laser power attenuator 160, and beam shaping module 120 are set to achieve a laser single pulse energy density of 1.4 J / cm2, a repetition frequency of 1100 kHz, one scan, a scanning speed of 100 mm / s, and a high-magnification processing lens 75 focal plane spot size of 6 μm * 3 μm. The pad cleaning command is executed, and a small spot low-power full-coverage scan is performed. The main purpose is to clean the small chip debris that was ejected outward in the form of plasma due to strong Coulomb repulsion in the previous step through thermal ablation.

[0073] After the above processing, defective chips on the Micro-LED display substrate can be completely removed. The processed pads are free of chip debris residue, and the damage to the metal layer on the pad surface is less than 150nm, meeting the technical requirements for subsequent resoldering of new chips.

[0074] In one possible implementation, in step S2, according to the set laser parameters: the pulse width of the femtosecond laser is 200fs to 600fs, the focusing energy density is 0.6J / cm2 to 40J / cm2, the laser scanning spacing is 0.5μm to 5μm, the laser scanning line spacing is 2μm to 10μm, the scanning speed is 1mm / s to 200mm / s, and the repetition frequency is 1100kHz to 1500kHz. In specific applications, in step S1, the sample is fixed by the processing stage 150 using vacuum adsorption and clamping; in step S2, the laser large spot irradiation is performed once, with an energy density of 30J / cm2 to 50J / cm2; in step S4, the laser large spot irradiation is performed once, with an energy density of 6J / cm2 to 17.5J / cm2; in step S6, the laser small spot irradiation is performed 1 to 2 times, and the scanning center point area (based on the center of the field of view of camera 146) is the chip length (L) * 1.8 and width (W) * 2, with an energy density of 0.6J / cm2 to 3J / cm2.

[0075] In one possible implementation, in step S2, the preset spot size is the chip size: the chip length is 25μm-30μm, the width is 10μm-15μm, and the height is 4μm-8μm. In specific applications, this invention combines chip removal with pad cleaning for integrated processing. First, a large spot of the same size as the chip is used to irradiate the chip twice at a relatively high power. The first irradiation is under positive defocus, and the spot is a narrow rectangular spot. During the irradiation, the chip surface undergoes ionization and thermal ablation, and the chip interior is also torn due to thermal stress. The second irradiation is under negative defocus, and the spot is a double rectangular spot, irradiating the two weaker ends of the chip connection. Through mechanical ablation, the torn chip is peeled off from the pads, and large chip debris is blown away from the sample by auxiliary gas. The removal effect is identified and analyzed by the identification and monitoring module 145. Then, a small spot low-power full-coverage scan is switched, and thermal ablation is used to clean the small chip debris that was ejected outward in the form of plasma due to strong Coulomb repulsion in the previous step and stuck to the pads.

[0076] The working principle of the laser removal method for defective Micro-LED chips: The laser beam emitted from laser 110 is first attenuated by laser power attenuator 160 to make its energy density suitable for the removal or cleaning stage; the beam then enters beam expander 170, which expands and collimates the Gaussian beam by a factor of 3, which helps to obtain a laser beam with a smaller focused spot diameter. Afterwards, the incident spot shape and size are adjusted by aperture adjustment component 121, while filtering out low-energy regions at the edge of the Gaussian beam. Finally, the laser energy is homogenized by first lens 122 and second lens 123. The laser beam is shaped into a rectangular beam. After shaping, the beam's propagation direction is changed by the saddle-shaped integrating mirror 130 and the first reflecting mirror 180 before entering the scanning galvanometer 141. The high-speed rotation of the motor in the scanning galvanometer 141 drives the mirrors on both axes to tilt, and the femtosecond laser beam enters the field mirror 142 for a two-dimensional high-speed scan in the horizontal plane. After the second reflecting mirror 143 changes its propagation direction, the beam enters the processing objective 144. The processing stage 150 is perpendicular to the processing mirror to ensure that the beam, after being focused by the low-magnification or high-magnification processing mirror, can reach the sample surface. The laser 110 is controlled by an industrial control computer 200 equipped with software. The system includes a laser power attenuator 160, a visualization processing module 140, a position synchronization output module (PSO), and a processing table 150. Images acquired in real-time by a camera 146 are identified and analyzed by a monitoring module 145. During processing, auxiliary gas is blown out through an auxiliary gas pipe 210. A beam splitter 147 is mainly used for beam splitting. A light source 148 is mainly used to provide light to the processing area. The software control in the industrial computer 200 can adjust the following parameters during processing: laser power (P), laser repetition frequency (F), attenuation percentage of the laser power attenuator 160, and scanning galvanometer 150. 41. The position synchronization output module (also known as PSO) controls the spot spacing (d1), scanning fill line spacing (d2), switching between low-magnification and high-magnification processing lenses, the movement of the processing stage 150 in the Y and Z directions, the movement of the visualization processing module 140 in the X direction, and the identification and analysis of the images acquired in real time by the camera 146 through the identification and monitoring module 145. This achieves uniform energy removal of large spot size, improves the processing quality of removing defective Micro-LED chips, reduces the thermal impact during processing, and improves the cleanliness of the processing area through vertical surface processing and small spot cleaning.

[0077] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A system for laser removal of defective chips of Micro-LEDs, characterized in that, The application relates to a laser processing device and a method thereof. The laser processing device comprises a laser, a beam shaping module, a saddle-shaped integrating mirror and a processing table. The laser outputs a femtosecond laser beam with a Gaussian intensity distribution. The beam shaping module comprises a diaphragm adjusting assembly, a first lens and a second lens. The diaphragm adjusting assembly is located behind the laser and adjusts the size of the femtosecond laser beam and filters out the low-energy area of the Gaussian beam edge. The first lens and the second lens are located behind the diaphragm adjusting assembly and are used for adjusting the energy of the homogenized femtosecond laser beam. 2.The system of claim 1, wherein, The saddle-shaped integrating mirror is located behind the beam shaping module and is used for adjusting the energy and shape of the shaped rectangular beam to form a light spot. 3.The system of claim 2, wherein, The incident light spot intensity distribution function of the light beam shaping module is Iin(r, θ), and the exit rectangular light spot intensity distribution is I out = rect(x / 2u, y / 2v), and the total energy of both is equal: The processing table is placed vertically to the horizontal plane and is used for adsorbing or clamping the substrate to be processed. 4.The system of claim 1-3, wherein, When the size of the rectangular beam of the femtosecond laser beam adjusted by the diaphragm adjusting assembly gradually decreases, the center distance of the double-rectangular beam light spot shaped by the saddle-shaped integrating mirror dynamically decreases. When the size of the rectangular beam of the femtosecond laser beam adjusted by the diaphragm adjusting assembly gradually increases, the center distance of the double-rectangular beam light spot shaped by the saddle-shaped integrating mirror dynamically increases. The diaphragm adjusting assembly comprises a first diaphragm sheet, a second diaphragm sheet, a third diaphragm sheet, a fourth diaphragm sheet and a driving element. Each diaphragm sheet is provided with a guide mechanism. The driving element drives the diaphragm sheets to move on the guide mechanisms. The first diaphragm sheet and the third diaphragm sheet are parallel to each other. The second diaphragm sheet and the fourth diaphragm sheet are parallel to each other. The first diaphragm sheet and the third diaphragm sheet move away from each other through the driving element. The second diaphragm sheet and the fourth diaphragm sheet move away from each other through the driving element. The first diaphragm sheet and the second diaphragm sheet are perpendicular to each other. The third diaphragm sheet and the fourth diaphragm sheet are perpendicular to each other. When the first diaphragm sheet and the second diaphragm sheet move vertically relative to each other, and the third diaphragm sheet and the fourth diaphragm sheet move vertically relative to each other, the length and width of the rectangular beam are adjusted. Wherein, r and theta are the polar coordinates of the incident plane, R is the beam radius, u and v are the edge length of the output rectangular spot, and x and y are the output plane coordinates. The saddle-shaped integrating mirror is composed of a first half-integrating mirror and a second half-integrating mirror. The first half-integrating mirror forms a first integrating surface, and the second half-integrating mirror forms a second integrating surface. The first integrating surface and the second integrating surface can rotate relative to the axis to shape and adjust the rectangular beam to form the light spot.

5. The system of claim 4, wherein the laser is configured to remove the defective chip by ablation. The first and second integrating surfaces on the saddle-shaped integrating mirror rotate at an angle of θ. When the first and second integrating surfaces rotate, they form a dynamic optical path with a radius of gyration of h. Wherein, f w is the working distance of the saddle type integrating mirror, D is the farthest distance between the first integrating surface and the second integrating surface, a w is the internal superposition length of the light spot, and a is the light spot length. 6.The system of claim 1, wherein, The laser removal system for defective Micro-LED chips includes a visualization processing module. This module comprises a scanning galvanometer, a field mirror, a second reflecting mirror, a processing objective lens, a recognition and monitoring module, a camera, a beam splitter, and a light source. The scanning galvanometer receives the light spot formed by the saddle-shaped integrating mirror and quickly scans it to the field mirror. The second reflecting mirror, located between the field mirror and the processing objective lens, reflects the light spot from the field mirror to the processing objective lens. The processing objective lens focuses the light spot onto the substrate to be processed. The beam splitter faces the substrate to be processed, and the light source illuminates the substrate through the beam splitter. The camera, located on one side of the beam splitter, acquires the focal image of the substrate in real time and uploads the acquired focal image information to the recognition and monitoring module.

7. The system of claim 1, wherein the laser is configured to remove the defective chip by ablation. The laser removal system for defective Micro-LED chips further includes a laser power attenuator, a beam expander, and a first reflector. The laser power attenuator is located between the laser and the beam shaping module, and attenuates the laser emitted by the laser to make the energy density of the laser beam suitable for the removal or cleaning stage. The beam expander is located between the laser power attenuator and the beam shaping module, and is used to expand the femtosecond laser beam with a Gaussian intensity distribution. The first reflector is located between the saddle-shaped integrating mirror and the visualization processing module, and is used to reflect the light spot generated by the saddle-shaped integrating mirror into the visualization processing module. The laser removal system for defective Micro-LED chips also includes a position synchronization module, an industrial computer, and an auxiliary air pipe. The position synchronization module is used to keep the output spacing of the laser constant, and the auxiliary air pipe is used to blow auxiliary gas into the laser focusing area of ​​the substrate to be processed. The industrial computer is connected to the laser power attenuator, the visualization processing module, the position synchronization module, and the processing table. 8.A method for laser removal of defective Micro-LED chips, applied to the system for laser removal of defective Micro-LED chips according to any one of claims 1-7, characterized in that, Including the following steps: S1. Fix the substrate to be processed on the processing table. The industrial control computer reads the CAD drawing with the marked defective chip positions, addresses by calibrating the Mark points, and focuses and aligns the camera with the center position of the defective chip. S2. Select a low-magnification processing objective lens, adjust the spot size to the chip size through the beam shaping module, and use the saddle-shaped integrating mirror to control the energy and shape distribution of the shaped rectangular beam to form a spot. The scanning galvanometer returns to zero, and the chip removal command is executed according to the set laser parameters. S3. The camera identifies image information indicating whether the defective chip on the pad of the substrate to be processed has been completely removed. The identification and monitoring module analyzes the image information. If the analysis shows that the defective chip on the pad of the substrate to be processed has been completely removed, then step S5 is executed; if the analysis shows that the defective chip on the pad of the substrate to be processed has not been completely removed, then step S4 is executed. S4. Based on the situation where the defective chip has not been completely removed, the energy distribution of the rectangular beam is dynamically adjusted by the aperture adjustment component and the saddle-shaped integrating mirror to form a new light spot. The chip removal command is executed again, and then the image information of whether the defective chip has been completely removed is identified. If it is found that the defective chip on the pad of the substrate to be processed has not been completely removed, step S4 is repeated. S5. The processing objective lens is switched to a high-magnification processing lens, and the visualization processing module compensates to the focal position according to the stored position, and reduces the laser energy density to the set value through the laser power attenuator. S6. Execute the pad cleaning command according to the set scanning trajectory, scanning interval, line spacing and laser parameters. 9.The method of claim 8, wherein, In step S2, the laser parameters are set as follows: the pulse width of the femtosecond laser is 200fs to 600fs, the focusing energy density is 0.6J / cm2 to 40J / cm2, the laser scanning spacing is 0.5μm to 5μm, the laser scanning line spacing is 2μm to 10μm, the scanning speed is 1mm / s to 200mm / s, and the repetition frequency is 1100KHZ to 1500KHZ. 10.The method of claim 8, wherein, In step S2, the preset spot size is the chip size: the chip size is 25μm to 30μm in length, 10μm to 15μm in width, and 4μm to 8μm in height.

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