Non-destructive laser cleaning method and equipment for microelectronic device based on dynamic layered focusing

Abstract

The invention relates to the field of welding flux laser cleaning, and provides a microelectronic device non-destructive laser cleaning method and equipment based on dynamic layered focusing, and the method comprises the steps: obtaining three-dimensional image data of a to-be-cleaned welding flux region of a to-be-cleaned welding flux on a chip or a bonding pad through visual imaging, so as to determine the maximum thickness value of the to-be-cleaned welding flux; generating a layer-by-layer laser cleaning path based on the maximum thickness value of the solder to be cleaned; based on the laser cleaning path, the to-be-cleaned welding flux is cleaned through short-focal-depth ultrafast laser; wherein the energy density at the laser focal point of the short-focal-depth ultrafast laser needs to be lower than the threshold energy density for damaging the chip or the bonding pad. By means of the dynamic layered focusing technology, laser energy accurately acts on the welding flux to be cleaned, energy deposition of a chip and a bonding pad is reduced, and damage and failure of a microelectronic device in the laser cleaning process are avoided to a great extent.

Description

Technical Field

[0001] This invention relates to the field of solder laser cleaning, specifically to a non-destructive laser cleaning method and equipment for microelectronic devices based on dynamic layered focusing. Background Technology

[0002] During the packaging process of microelectronic devices, after the solder and flux react at high temperatures, a small amount of solder can remain on the chip surface, pads, and gaps. This residual solder can not only directly cause mechanical short circuits but may also induce electrochemical migration through moisture absorption, leading to a decrease in insulation resistance or metal corrosion, and in severe cases, rendering the chip unusable. Therefore, to ensure the yield rate of microelectronic devices, a process for cleaning residual solder is necessary.

[0003] Traditional cleaning methods all have significant shortcomings. For example, manual cleaning with cotton swabs is inefficient and produces poor cleaning consistency, making it difficult to meet industrial requirements. Mechanical brushing can easily lead to micro-cracks in solder joints, scratches on pads, or brittle fracture of chips. While wet chemical cleaning can effectively dissolve residues, it can easily corrode devices and has difficulty drying, while the cost of treating chemical waste is high, failing to meet environmental protection requirements. Therefore, there is a need to research new methods for cleaning residual solder.

[0004] Laser cleaning technology, as a gradually developing new technology, has advantages such as high efficiency, non-contact operation, and environmental friendliness. However, it also faces bottlenecks in practical applications. During the laser cleaning process of microelectronic devices, the laser energy deposited on the chip or other key areas excites electron-hole pairs. For chips, a hundred nanojoules of laser energy is sufficient to create a single-particle burn-off effect, causing irreversible damage. For other key areas, such as excess solder on pads, the metal of the pads has high laser absorption, easily depositing laser heat, causing thermal expansion or vaporization, resulting in irreversible damage. Furthermore, the submicron-sized solder vapors generated during laser cleaning are easily re-adsorbed onto the device surface due to electrostatic discharge, causing secondary contamination.

[0005] As chip manufacturing processes evolve towards 3nm and below, increased packaging density leads to a reduction in pad spacing to below 40μm, placing higher demands on cleaning precision and material compatibility. Traditional cleaning methods and existing laser technologies are insufficient to meet the stringent standards of advanced processes. Therefore, a novel laser cleaning method is needed to adapt to non-destructive cleaning applications for microelectronic devices. Summary of the Invention

[0006] Given that traditional cleaning methods and existing laser technologies are difficult to meet the stringent standards of advanced manufacturing processes, this invention provides a non-destructive laser cleaning method and equipment for microelectronic devices based on dynamic layered focusing, in order to adapt to non-destructive cleaning applications of microelectronic devices.

[0007] In a first aspect, the present invention provides a non-destructive laser cleaning method for microelectronic devices based on dynamic layered focusing, comprising: Three-dimensional image data of the solder area to be cleaned on the chip or pad is obtained by visual imaging to determine the maximum thickness of the solder to be cleaned. A layer-by-layer laser cleaning path is generated based on the maximum thickness of the solder to be cleaned. Based on the laser cleaning path, a short depth-of-focus ultrafast laser is used to clean the solder to be cleaned; wherein, the energy density at the laser focal point of the short depth-of-focus ultrafast laser needs to be lower than the threshold energy density that would damage the chip or solder pad.

[0008] In a preferred embodiment, cleaning the solder to be cleaned using a short depth-of-focus ultrafast laser includes: The laser focus of the short depth-of-focus ultrafast laser is set to a negative defocus state, and the solder to be cleaned on the chip surface is cleaned layer by layer. The energy density F1 acting on the chip surface satisfies... F 1max The threshold energy density to prevent chip damage; After cleaning the chip, the laser focus of the short depth-of-focus ultrafast laser is switched to positive defocus state, and the solder to be cleaned on the surface of the pads is cleaned layer by layer. The energy density F2 acting on the surface of the pads meets the requirements. F 2max The threshold energy density required to cause pad damage.

[0009] In a preferred embodiment, the formula for calculating the energy density F1 acting on the chip surface is as follows:

[0010] Where F is the energy density at the laser focal point of the short depth-of-focus ultrafast laser, and z1 is the negative defocusing amount.

[0011] In a preferred embodiment, the formula for calculating the energy density F2 acting on the pad surface is as follows:

[0012] Where F is the energy density at the laser focal point of the short depth-of-focus ultrafast laser, and z2 is the positive defocusing amount.

[0013] In a preferred embodiment, the formula for calculating the energy density at the laser focal point of a short depth-of-focus ultrafast laser is as follows: F=4E / (πd 2 ) Where E is the single pulse energy and d is the diameter of the focused spot.

[0014] In a preferred embodiment, during the process of cleaning the solder to be cleaned using a short depth-of-focus ultrafast laser, high-pressure air extraction is performed simultaneously to remove dust particles generated during the cleaning process.

[0015] In a preferred embodiment, the method for generating layer-by-layer laser cleaning paths based on the maximum thickness of the solder to be cleaned is as follows: The number of layers is calculated based on the maximum thickness of the solder to be cleaned and the laser focal depth. Generate layer-by-layer laser cleaning paths based on the number of layers; The formula for calculating the number of layers is as follows: N=H / D Where N is the number of layers, H is the maximum thickness of the solder to be cleaned, and D is the laser focal depth.

[0016] Secondly, the present invention provides a non-destructive laser cleaning equipment for microelectronic devices based on dynamic layered focusing, including a high-magnification objective lens, a laser, a dynamic focusing system, a dual-color mirror, a visual imaging module, and a control module. The laser is used to emit short depth-of-focus ultrafast laser, which is then applied to a dichroic mirror via a dynamic focusing system. The dichroic mirror is used to reflect short depth-of-focus ultrafast lasers. The reflected short depth-of-focus ultrafast lasers are focused by a high-magnification objective lens to reach the solder to be cleaned on the chip or pad. It is also used to transmit white light from the solder to be cleaned on the chip or pad to the visual imaging module, so as to realize that the laser path and the visual path are coaxial. The dynamic focusing system is used to adjust the laser focus position of the short depth-of-focus ultrafast laser on the solder to be cleaned on the chip or pad. The visual imaging module is used to acquire three-dimensional image data of the solder area to be cleaned on the chip or pad and transmit it to the control module; The control module is used to receive the three-dimensional image data, generate layered cleaning instructions based on the three-dimensional image data according to the above-mentioned non-destructive laser cleaning method for microelectronic devices based on dynamic layered focusing, and synchronously control the laser and the dynamic focusing system.

[0017] In a preferred embodiment, the high-magnification objective lens is a high-magnification objective lens with integrated high-pressure evacuation function; the high-magnification objective lens with integrated high-pressure evacuation function is controlled by a control module.

[0018] In a preferred embodiment, the high-magnification objective lens with integrated high-pressure evacuation function includes a housing and a high-pressure evacuation device, which is controlled by a control module. A window mirror is provided at the upper end of the housing, and an air extraction window is provided at the lower end of the housing; a high-magnification objective lens is provided between the window mirror and the air extraction window, and a window protection lens is provided between the high-magnification objective lens and the air extraction window; a high-pressure air extraction port is provided on one side of the upper end of the housing; in use, the air extraction window is aligned with the solder to be cleaned, and a high-pressure air extraction device is used to extract air from the high-pressure air extraction port.

[0019] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. A key challenge of existing laser cleaning technologies is that high-power-density laser deposition inside chips can cause single-particle burn-off effects, resulting in irreversible hard damage. Therefore, it is necessary to strictly control the laser energy density deposited inside the chip during solder cleaning. This invention utilizes dynamic layered focusing technology to precisely target laser energy onto the solder to be cleaned, reducing energy deposition on the chip and pads, and significantly minimizing damage and failure of microelectronic devices during laser cleaning.

[0020] 2. This invention combines three-dimensional visual imaging to divide the solder thickness and plan the layered cleaning path, and performs submicron-level layered cleaning to achieve adaptive cleaning of residual solder with complex shapes, effectively improving the cleaning rate.

[0021] 3. The present invention employs different defocusing methods for the chip and the pad, wherein the chip employs negative defocusing to significantly reduce the peak power density of the deposited laser, and the pad employs positive defocusing to expand the laser cleaning area.

[0022] 4. This invention uses a high-magnification objective lens for focusing to obtain an extremely small depth of focus range. Combined with dynamic layered focusing technology, this further enables the laser energy to be precisely applied to the solder to be cleaned, reducing energy deposition on the chip and pad, and greatly avoiding damage and failure of microelectronic devices during the laser cleaning process.

[0023] 5. This invention innovatively integrates a high-pressure evacuation function into a high-magnification objective lens. During the cleaning process, air is simultaneously extracted from the high-pressure evacuation port to remove vaporized particles in real time, significantly reducing solder residue and minimizing the risk of secondary contamination.

[0024] 6. The high-magnification objective lens of this invention, which integrates high-pressure air extraction function, adopts a sandwich design of window lens + window protective lens, which isolates the high-magnification objective lens from the external environment, reduces the possibility of contamination of high-precision optical components, and thus reduces maintenance costs. Attached Figure Description

[0025] Figure 1 This is a flowchart of a non-destructive laser cleaning method for microelectronic devices based on dynamic layered focusing, provided as an embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of the solder to be cleaned on the chip or pad in an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of a non-destructive laser cleaning equipment for microelectronic devices based on dynamic layered focusing, provided as an embodiment of the present invention.

[0028] Figure 4This is a schematic diagram of the structure of a high-magnification objective lens integrating high-pressure air extraction function in an embodiment of the present invention.

[0029] icon: 100 - Solder to be cleaned, 101 - Pad, 102 - Chip; 201-Laser, 202-Dynamic focusing system, 203-High-magnification objective lens with integrated high-pressure pumping function, 204-Dichroic mirror, 205-Visual imaging module; 301-Housing shell, 302-Window mirror, 303-Evacuation window, 304-High magnification objective lens, 305-Window protection mirror, 306-High pressure evacuation port, 307-Incident laser. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0032] Example like Figure 1 As shown in the figure, an embodiment of the present invention provides a non-destructive laser cleaning method for microelectronic devices based on dynamic layered focusing, comprising the following steps: S100 acquires three-dimensional image data of the solder area to be cleaned on the chip or pad through visual imaging in order to determine the maximum thickness of the solder to be cleaned. S200 generates a layer-by-layer laser cleaning path based on the maximum thickness of the solder to be cleaned; The S300 uses a short depth-of-focus ultrafast laser to clean the solder, based on a laser cleaning path. The energy density at the laser focal point of the short depth-of-focus ultrafast laser needs to be lower than the threshold energy density that would damage the chip or pad.

[0033] Through the above-mentioned non-destructive laser cleaning method for microelectronic devices based on dynamic layered focusing, this invention enables laser energy to be precisely applied to the solder to be cleaned by dynamic layered focusing technology, reducing energy deposition on chips and pads, and greatly avoiding damage and failure of microelectronic devices during laser cleaning.

[0034] The following details the specific implementation of the aforementioned non-destructive laser cleaning method for microelectronic devices based on dynamic layered focusing. The solder to be cleaned on the chip or pads is as follows: Figure 2 As shown. The cleaning method includes: S100: Obtain three-dimensional image data of the area of ​​the solder 100 to be cleaned on the chip 102 or pad 101 through visual imaging to determine the maximum thickness of the solder 100 to be cleaned; wherein the three-dimensional image data can be obtained by existing visual imaging technology, and the size of the target object can also be obtained from the three-dimensional image data by existing image processing technology, which will not be elaborated here.

[0035] S200 generates a layer-by-layer laser cleaning path based on the maximum thickness of the solder to be cleaned (100mm); specifically: The number of layers is calculated based on the maximum thickness of the solder to be cleaned (100mm) and the laser focal depth. Generate layer-by-layer laser cleaning paths based on the number of layers; The formula for calculating the number of layers is as follows: N=H / D Where N is the number of layers, H is the maximum thickness of the solder to be cleaned (100), and D is the laser focal depth.

[0036] S300, based on a laser cleaning path, uses a short depth-of-focus ultrafast laser to clean the solder 100 to be cleaned; wherein, the energy density at the laser focal point of the short depth-of-focus ultrafast laser needs to be lower than the threshold energy density that would damage the chip 102 or the pad 101. Specifically: S301, the laser focus of the short depth-of-focus ultrafast laser is set to a negative defocus state, and the solder 100 to be cleaned on the surface of chip 102 is cleaned layer by layer. The cleaning time of a single layer in the layer-by-layer cleaning process is preferably less than or equal to 2 seconds, and the energy density F1 acting on the surface of chip 102 satisfies F 1max The threshold energy density required to damage chip 102 is preferably 0.4 J / cm³. 2 The formula for calculating the energy density F1 acting on the surface of chip 102 is as follows:

[0037] Where F is the energy density at the laser focal point of the short depth-of-focus ultrafast laser, and z1 is the negative defocusing amount.

[0038] S302, after cleaning chip 102, the laser focus of the short depth-of-focus ultrafast laser is switched to positive defocus state, and the solder 100 to be cleaned on the surface of pad 101 is cleaned layer by layer. The cleaning time of a single layer during the layer-by-layer cleaning process is preferably less than or equal to 2 seconds, and the energy density F2 acting on the surface of pad 101 satisfies F2max The threshold energy density required to damage pad 101 is preferably 1 J / cm². 2 The formula for calculating the energy density F2 acting on the surface of pad 101 is as follows:

[0039] Where F is the energy density at the laser focal point of the short depth-of-focus ultrafast laser, and z2 is the positive defocusing amount.

[0040] The formula for calculating the energy density at the laser focal point of the aforementioned short depth-of-focus ultrafast laser is as follows: F=4E / (πd 2 ) Where E is the single pulse energy and d is the diameter of the focused spot.

[0041] During the cleaning process, the ultrafast laser ensures sufficiently low single-pulse energy, while the short depth of focus allows the laser to rapidly diverge outside the direct action area, thus minimizing laser energy deposition on the surfaces of chip 102 and pad 101 in the defocused state. The preferred depth of focus is less than or equal to 10 μm. The defocusing state can be switched according to different scenarios to meet the cleaning requirements of chip 102 and pad 101 respectively. Specifically, negative defocusing is used on chip 102 to significantly reduce the peak power density of the deposited laser, while positive defocusing is used on pad 101 to expand the laser cleaning area. The preferred defocusing amount in the defocused state is 5 μm-20 μm.

[0042] Furthermore, during the process of cleaning the solder 100 to be cleaned using a short depth of focus ultrafast laser, high-pressure air extraction is performed simultaneously to remove dust particles generated during the cleaning process of the solder 100 to significantly improve the real-time decontamination effect; wherein, the air extraction rate of the high-pressure air extraction is preferably greater than 20L / min.

[0043] To achieve the aforementioned non-destructive laser cleaning method for microelectronic devices based on dynamic layered focusing, such as... Figure 3 As shown, this embodiment of the invention provides a non-destructive laser cleaning equipment for microelectronic devices based on dynamic layered focusing, including a high-magnification objective lens, a laser 201, a dynamic focusing system 202, a dichroic mirror 204, a visual imaging module 205, and a control module (not shown). The laser 201 is used to emit short depth-of-focus ultrafast laser, which is then focused by a dynamic focusing system 202 to a dichroic mirror 204. Preferably, the short depth-of-focus ultrafast laser emitted by the laser 201 is a femtosecond laser or a picosecond laser, with a single pulse energy of 50nJ-500nJ, a repetition rate of 1kHz-10kHz, and a focused spot diameter of 4-10μm.

[0044] The dichroic mirror 204 is used to reflect short depth-of-focus ultrafast laser. The reflected short depth-of-focus ultrafast laser is focused by a high-magnification objective lens to reach the solder 100 to be cleaned on the chip 102 or the pad 101; and is used to transmit white light from the solder 100 to be cleaned on the chip 102 or the pad 101 to the visual imaging module 205, so as to realize that the laser path and the visual path are coaxial. The dynamic focusing system 202 is used to adjust the laser focus position of the short depth of focus ultrafast laser on the solder 100 to be cleaned on the chip 102 or the pad 101; preferably, the dynamic focusing system 202 has an adjustment accuracy of less than or equal to 0.1 μm, a response time of less than or equal to 20 ms, and a stroke range of 500 μm-2000 μm.

[0045] The visual imaging module 205 is used to acquire three-dimensional image data of the area of ​​solder 100 to be cleaned on the chip 102 or the pad 101, and transmit it to the control module; preferably, the imaging accuracy of the visual imaging module 205 is less than or equal to 0.05μm.

[0046] The control module is used to receive the three-dimensional image data, generate layered cleaning instructions based on the three-dimensional image data according to the above-mentioned non-destructive laser cleaning of microelectronic devices based on dynamic layered focusing, and synchronously control the laser 201 and the dynamic focusing system 202.

[0047] To achieve high-pressure air extraction during the cleaning process, the high-magnification objective lens in this embodiment of the invention is a high-magnification objective lens 203 with integrated high-pressure air extraction function; the high-magnification objective lens 203 with integrated high-pressure air extraction function is controlled by a control module. For example... Figure 4 As shown, the high-magnification objective lens 203 with integrated high-pressure evacuation function includes a housing 301 and a high-pressure evacuation device (not shown), which is controlled by a control module. A window mirror 302 is provided at the upper end of the housing 301, and an exhaust window 303 is provided at the lower end of the housing 301; a high-magnification objective lens 304 is provided between the window mirror 302 and the exhaust window 303, and a window protection mirror 305 is provided between the high-magnification objective lens 304 and the exhaust window 303; a high-pressure exhaust port 306 is provided on one side of the upper end of the housing 301; in use, the exhaust window is aligned with the solder 100 to be cleaned, and a high-pressure exhaust device is used to extract air from the high-pressure exhaust port 306.

[0048] A specific example: Laser 201 is a femtosecond fiber laser with a wavelength of 1030 nm, a pulse width of 300 fs, a repetition rate of 5 kHz, and a single pulse energy of 200 nJ. The high-magnification objective lens 304NA=0.6 has a focused spot diameter of 5 μm and a depth of focus of 5 μm. The dynamic focusing system 202 is an objective lens displacement stage with an adjustment accuracy of 0.05 μm and a response time of 5 ms. The high-pressure evacuation port 306 has a evacuation rate of 60 L / min. The visual imaging module 205 uses a confocal microscope with a three-dimensional imaging accuracy of 0.02 μm. The test sample is a 5 mm × 5 mm silicon-based chip 102, with a surface covered by a 40 ± 5 μm thick SnAgCu solder layer, which partially covers the underlying aluminum pad 101.

[0049] The sample was placed and scanned using a confocal microscope to obtain the three-dimensional distribution of the solder 100 to be cleaned. The maximum solder thickness H = 44 μm. Based on the depth of focus, the sample was divided into N = 9 cleaning layers, generating a layer-by-layer laser cleaning path. High-pressure air extraction was activated, and the focus was set to a negative defocus of 15 μm using the dynamic focusing system 202 to perform layer-by-layer scanning cleaning of the chip 102, with a single-layer scanning time of 0.4 seconds. Subsequently, the focus was set to a positive defocus of 8 μm to perform layer-by-layer scanning cleaning of the pads 101, with a single-layer scanning time of 0.6 seconds. After cleaning, testing was conducted to verify the cleaning effect.

[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A non-destructive laser cleaning method for microelectronic devices based on dynamic layered focusing, characterized in that, include: Three-dimensional image data of the solder area to be cleaned on the chip or pad is obtained by visual imaging to determine the maximum thickness of the solder to be cleaned. A layer-by-layer laser cleaning path is generated based on the maximum thickness of the solder to be cleaned. Based on the laser cleaning path, a short depth-of-focus ultrafast laser is used to clean the solder to be cleaned; wherein, the energy density at the laser focal point of the short depth-of-focus ultrafast laser needs to be lower than the threshold energy density that would damage the chip or solder pad.

2. The non-destructive laser cleaning method for microelectronic devices based on dynamic layered focusing according to claim 1, characterized in that, Short depth-of-focus ultrafast laser cleaning of solder to be cleaned includes: The laser focus of the short depth-of-focus ultrafast laser is set to a negative defocus state, and the solder to be cleaned on the chip surface is cleaned layer by layer. The energy density F1 acting on the chip surface satisfies... F 1max The threshold energy density to prevent chip damage; After cleaning the chip, the laser focus of the short depth-of-focus ultrafast laser is switched to positive defocus state, and the solder to be cleaned on the surface of the pads is cleaned layer by layer. The energy density F2 acting on the surface of the pads meets the requirements. F 2max The threshold energy density required to damage the solder pads.

3. The non-destructive laser cleaning method for microelectronic devices based on dynamic layered focusing according to claim 2, characterized in that, The formula for calculating the energy density F1 acting on the chip surface is as follows: Where F is the energy density at the laser focal point of the short depth-of-focus ultrafast laser, and z1 is the negative defocusing amount.

4. The non-destructive laser cleaning method for microelectronic devices based on dynamic layered focusing according to claim 2, characterized in that, The formula for calculating the energy density F2 acting on the pad surface is as follows: Where F is the energy density at the laser focal point of the short depth-of-focus ultrafast laser, and z2 is the positive defocusing amount.

5. The non-destructive laser cleaning method for microelectronic devices based on dynamic layered focusing according to claim 3 or 4, characterized in that, The formula for calculating the energy density at the laser focal point of a short depth-of-focus ultrafast laser is as follows: F=4E / (πd 2 ) Where E is the single pulse energy and d is the diameter of the focused spot.

6. The non-destructive laser cleaning method for microelectronic devices based on dynamic layered focusing according to claim 1, characterized in that, During the process of cleaning solder using a short depth-of-focus ultrafast laser, high-pressure air extraction is performed simultaneously to remove dust particles generated during the cleaning process.

7. The non-destructive laser cleaning method for microelectronic devices based on dynamic layered focusing according to claim 1, characterized in that, The method for generating layer-by-layer laser cleaning paths based on the maximum thickness of the solder to be cleaned is as follows: The number of layers is calculated based on the maximum thickness of the solder to be cleaned and the laser focal depth. Generate layer-by-layer laser cleaning paths based on the number of layers; The formula for calculating the number of layers is as follows: N=H / D Where N is the number of layers, H is the maximum thickness of the solder to be cleaned, and D is the laser focal depth.

8. A non-destructive laser cleaning equipment for microelectronic devices based on dynamic layered focusing, characterized in that, It includes a high-magnification objective lens, a laser, a dynamic focusing system, a diachromatic mirror, a vision imaging module, and a control module; The laser is used to emit short depth-of-focus ultrafast laser, which is then applied to a dichroic mirror via a dynamic focusing system. The dichroic mirror is used to reflect short depth-of-focus ultrafast lasers. The reflected short depth-of-focus ultrafast lasers are focused by a high-magnification objective lens to reach the solder to be cleaned on the chip or pad. It is also used to transmit white light from the solder to be cleaned on the chip or pad to the visual imaging module, so as to realize that the laser path and the visual path are coaxial. The dynamic focusing system is used to adjust the laser focus position of the short depth-of-focus ultrafast laser on the solder to be cleaned on the chip or pad. The visual imaging module is used to acquire three-dimensional image data of the solder area to be cleaned on the chip or pad and transmit it to the control module; The control module is used to receive the three-dimensional image data, generate a layered cleaning instruction based on the three-dimensional image data in accordance with the method described in any one of claims 1-6, and synchronously control the laser and the dynamic focusing system.

9. The non-destructive laser cleaning equipment for microelectronic devices based on dynamic layered focusing according to claim 8, characterized in that, The high-magnification objective lens is a high-magnification objective lens with integrated high-pressure air extraction function; the high-magnification objective lens with integrated high-pressure air extraction function is controlled by the control module.

10. The non-destructive laser cleaning equipment for microelectronic devices based on dynamic layered focusing according to claim 9, characterized in that, The high-magnification objective lens with integrated high-pressure evacuation function includes a housing and a high-pressure evacuation device, which is controlled by a control module. A window mirror is provided at the upper end of the housing, and an air extraction window is provided at the lower end of the housing; a high-magnification objective lens is provided between the window mirror and the air extraction window, and a window protection lens is provided between the high-magnification objective lens and the air extraction window; a high-pressure air extraction port is provided on one side of the upper end of the housing; in use, the air extraction window is aligned with the solder to be cleaned, and a high-pressure air extraction device is used to extract air from the high-pressure air extraction port.

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