Method for manufacturing glass via hole

Abstract

The application discloses a preparation method of a glass via, and relates to the technical field of laser processing. The technical scheme of the application adopts a two-stage laser pulse string step-by-step modification process mode, first forms a continuous first modification region in a glass substrate by a first laser pulse string, and effectively guarantees the integrity and continuity of a subsequent etching path. Meanwhile, the application divides the first modification region into a plurality of second modification regions with different depths according to the depth position of the thickness direction of the glass substrate, and carries out targeted selective reinforcement modification on the regions with different depths by a second laser pulse string, so that longitudinal compensation of the etching rate in the thickness direction of the glass substrate is realized.

Description

Technical Field

[0001] This invention relates to the field of laser processing technology, and in particular to a method for preparing glass vias. Background Technology

[0002] The demand for high-speed, high-frequency interconnects in the current high-end packaging field is surging. Glass has become the preferred material for interposers due to its excellent performance, and the fabrication of glass vias (including through holes and blind holes) is its core process.

[0003] The existing mainstream process route of "laser modification + wet etching" has obvious drawbacks. The longitudinal attenuation of the etching solution concentration can easily cause the via to form a tapered structure that is "larger at the top and smaller at the bottom", which affects the integrity of electroplating filling, the transmission quality of high-frequency signals and the realization of high-density wiring, and is difficult to be compatible with blind via fabrication.

[0004] To address the aforementioned issues, existing technologies have proposed improvements such as double-sided laser processing and optimized etching formulas. However, these solutions suffer from drawbacks such as complex processes, limited improvement effects, and a tendency to cause aperture runaway. Consequently, they are difficult to efficiently fabricate low-taper, high-precision glass vias, and thus fail to meet the mass production requirements of high-end packaging. Summary of the Invention

[0005] The purpose of this invention is to propose a method for preparing glass vias, which aims to compensate for longitudinal differences in etching rates and achieve the preparation of glass vias with low taper or even zero taper.

[0006] To achieve this objective, the present invention adopts the following technical solution: A method for preparing a glass via includes the following steps: A. Provide glass substrates; B. Focus a first laser pulse train parallel to the thickness direction of the glass substrate onto the upper surface of the glass substrate, and move the focal point formed by the first laser pulse train along the thickness direction of the glass substrate to a predetermined depth to form a first modified region. C. According to the preset depth position, the first modified region is divided into multiple second modified regions along the thickness direction of the glass substrate. The second laser pulse train is focused on the second modified region for scanning. According to the depth position corresponding to the second modified region, the scanning parameters of the second laser pulse train are adjusted accordingly to form multiple compensated modified regions. D. Immerse the glass substrate in an etching solution, and after etching, a glass via is formed; The glass vias include at least through holes and blind holes.

[0007] Preferably, the average power of the first laser pulse train is greater than the average power of the second laser pulse train.

[0008] Preferably, in step B, the average power of the first laser pulse train is 0.3 to 50 W.

[0009] Preferably, in step C, the average power of the second laser pulse train increases from the upper surface of the glass substrate to the lower surface of the glass substrate; And / or, the number of scans of the second laser pulse train increases from the upper surface of the glass substrate to the lower surface of the glass substrate.

[0010] Preferably, in step C, the average power of the second laser pulse train is 0.2 to 30 W.

[0011] Preferably, the plurality of second modified regions are uniformly distributed along the thickness direction of the glass substrate.

[0012] Preferably, in step B, the focal diameter of the first laser pulse train is less than or equal to the diameter of the glass via. When the glass via is a glass through-hole, the preset depth is equal to the depth of the glass through-hole; When the glass via is a blind glass via, the preset depth is less than or equal to the depth of the blind glass via.

[0013] Preferably, in step C, the scanning area of ​​the second laser pulse train in any of the second modified regions is less than or equal to the cross-sectional area of ​​the glass via.

[0014] Preferably, in step A, the thickness of the glass substrate is 1 to 1000 μm, and the glass substrate is any one of quartz glass, borosilicate glass, aluminosilicate glass, soda-lime glass, phosphate glass, and borosilicate glass. In step B, the first laser pulse train is a femtosecond laser or a picosecond laser with a wavelength of 700–1500 nm; When the first laser pulse train is a femtosecond laser, the pulse width is 10 to 600 fs; When the first laser pulse train is a picosecond laser, the pulse width is 10 to 800 ps; In step C, the second laser pulse train is a femtosecond laser or a picosecond laser with a wavelength of 700–1500 nm; When the second laser pulse train is a femtosecond laser, the pulse width is 10–600 fs; When the second laser pulse train is a picosecond laser, the pulse width is 10–800 ps; In step D, the etching solution is either a hydrofluoric acid solution or a potassium hydroxide solution.

[0015] Preferably, the taper of the glass through-hole is less than 0.1°.

[0016] The technical solution provided by this invention may include the following beneficial effects: The technical solution of this invention employs a two-stage laser pulse train stepwise modification process. First, a continuous first modification region is formed inside the glass substrate using a first laser pulse train, effectively ensuring the integrity and continuity of the subsequent etching path. Simultaneously, based on the depth position along the thickness direction of the glass substrate, this invention divides the first modification region into multiple second modification regions of different depths, and then uses a second laser pulse train to selectively reinforce and modify each depth region, achieving longitudinal compensation of the etching rate along the thickness direction of the glass substrate. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the preparation method in Embodiment 1 of the present invention.

[0018] Figure 2 This is a schematic diagram of the preparation method in Embodiment 3 of the present invention. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0020] With the rapid development of high-end information technology fields such as cloud computing, artificial intelligence, and supercomputing, the requirements for data transmission rates, bandwidth, and integration density of high-performance computing systems are continuously increasing. Traditional resin-based electrical interconnect technologies, limited by material dielectric properties, high-frequency losses, and wiring accuracy, can no longer meet the application needs of next-generation high-density, high-frequency, and high-speed packaging. Compared to traditional substrate materials, glass materials have advantages such as low dielectric constant, adjustable coefficient of thermal expansion, and low cost, and have become a core candidate material for high-end packaging interposer substrates, with broad application prospects in high-density packaging and high-frequency interconnects.

[0021] In the fabrication process of glass interposers, the high-precision and high-quality fabrication of glass vias (including through-hole and blind-hole vias) is the core key to determining the interconnect performance and packaging reliability of the substrate, directly affecting subsequent metallization filling, high-density wiring, and overall packaging effect. Currently, the mainstream glass via fabrication process in the industry is an integrated process combining ultrafast laser modification and wet etching. This process has become the mainstream technical solution for glass via fabrication due to its high processing precision, wide adaptability, and controllable cost. Its process principle is as follows: Ultrafast lasers are used to irradiate a designated area of ​​the glass substrate, causing material modification in the pre-set channel area inside the substrate, forming a modified region with physicochemical properties different from the base glass; subsequently, wet etching is performed using etching solutions such as hydrofluoric acid to selectively remove the material in the modified region, ultimately forming the glass through-hole or blind-hole structure.

[0022] In the fabrication process of glass interposers, the high-precision and high-quality fabrication of glass vias (including glass through-holes and glass blind vias) is the core key to determining the interconnect performance and packaging reliability of the substrate, directly affecting subsequent metallization filling, high-density wiring, and overall packaging effect. Currently, the mainstream glass via fabrication process in the industry is a combination of laser modification and wet etching. This process has become the mainstream technology for glass via fabrication due to its high processing precision, wide adaptability, and controllable cost. The process principle is as follows: Ultrafast lasers are used to irradiate a designated area of ​​the glass substrate, causing material modification in the pre-defined via area within the substrate, forming a modified region with physicochemical properties different from the base glass; subsequently, wet etching is performed using etching solutions such as hydrofluoric acid to selectively remove the material from the modified region, ultimately forming a glass through-hole or blind via structure.

[0023] However, existing laser modification combined with wet etching processes are mostly designed for the forming needs of glass vias. The process parameters and etching logic cannot be adapted to the precise preparation needs of blind holes. The industry lacks a unified process solution that can be compatible with the integrated preparation of vias and blind holes, making it difficult to meet the processing needs of both types of glass vias. The process has poor versatility and adaptability.

[0024] Furthermore, the existing mainstream "laser modification + wet etching" process has significant drawbacks. The longitudinal attenuation of the etching solution concentration easily leads to the formation of a tapered structure with a larger top and smaller bottom in the vias. To improve the aforementioned channel taper problem, existing technologies have proposed various optimization schemes, including using double-sided laser modification processing, optimizing the etching solution composition formula, and extending the wet etching time. However, all of the above improvement schemes have significant drawbacks: double-sided laser processing requires precise alignment laser treatment on both sides of the glass substrate, which greatly increases the complexity of the process and the difficulty of equipment debugging, reduces processing efficiency, and increases mass production costs; optimizing the etching solution formula can only slightly improve etching uniformity, and its compensation effect on longitudinal etching rate differences is limited, failing to fundamentally eliminate the channel taper defect; simply extending the etching time can weaken the taper problem to some extent, but it is very easy to cause secondary defects such as over-etching of the channel edges, uncontrolled hole diameter, and deterioration of hole wall roughness, leading to a decrease in product yield.

[0025] In summary, existing glass via fabrication processes suffer from numerous technical problems, such as large channel taper, incompatibility between through-hole and blind-hole fabrication, limited process optimization, and poor mass production stability. These issues make it difficult to meet the high-end packaging industry's demand for mass production of low-taper, high-precision, and multi-type glass vias.

[0026] Therefore, there is an urgent need to develop a fabrication method that does not require significant modifications to existing processes, can effectively compensate for differences in etching longitudinal rates, is compatible with the fabrication of through-holes and blind holes, and can achieve the fabrication of low-tapered or even zero-tapered glass vias. To this end, this technical solution proposes a method for fabricating glass vias, including the following steps: A. Provide glass substrates; B. Focus a first laser pulse train parallel to the thickness direction of the glass substrate onto the upper surface of the glass substrate, and move the focal point formed by the first laser pulse train along the thickness direction of the glass substrate to a predetermined depth to form a first modified region. C. According to the preset depth position, the first modified region is divided into multiple second modified regions along the thickness direction of the glass substrate. The second laser pulse train is focused on the second modified region for scanning. According to the depth position corresponding to the second modified region, the scanning parameters of the second laser pulse train are adjusted accordingly to form multiple compensated modified regions. D. Immerse the glass substrate in an etching solution, and after etching, a glass via is formed; The glass vias include at least through holes and blind holes.

[0027] The technical solution of this invention employs a two-stage laser pulse train stepwise modification process. First, a first laser pulse train forms a continuous initial modification channel (i.e., a first modification region) within the glass substrate, effectively ensuring the integrity and continuity of the subsequent etching path. Simultaneously, based on the depth position along the thickness direction of the glass substrate, this invention divides the first modification region into multiple second modification regions of different depths. The second laser pulse train then selectively reinforces and modifies each depth region, achieving longitudinal compensation of the etching rate along the thickness direction of the glass substrate.

[0028] This solution optimizes etching matching based on the distribution of the laser-modified region, without requiring significant modifications to the existing etching solution system and etching process. It effectively overcomes the problem of uneven etching rate caused by limited longitudinal mass transfer and concentration decay in the depth direction in traditional single laser modification processes, improves the tapered defect of glass vias that are larger at the top and smaller at the bottom, and effectively prepares glass via structures with low taper and regular hole shape.

[0029] Furthermore, the preparation method of this solution is compatible with the integrated preparation of glass through holes and glass blind holes. By simply controlling whether the first modified region formed by the first laser pulse train penetrates the glass substrate, the preparation of through holes or blind holes can be selectively achieved. This realizes the flexible adjustment of the hole structure under the same process system, greatly improves the versatility of the glass through hole preparation process, effectively solves the technical shortcomings of the existing process that cannot simultaneously process through holes and blind holes, and adapts to diversified mass production preparation needs.

[0030] It should be noted that in step A of this solution, the glass substrate can be cleaned. In one specific embodiment, acetone, anhydrous ethanol, and deionized water can be used sequentially for ultrasonic cleaning for 15 minutes to remove surface contaminants, followed by drying in an oven and cooling to room temperature. In step B of this solution, the preset depth is related to the depth of the final formed glass via. This solution can adjust the movement distance of the focal spot in the first laser pulse train according to the depth of the glass via.

[0031] To further explain, the average power of the first laser pulse train is greater than the average power of the second laser pulse train.

[0032] In a preferred embodiment of this technical solution, by limiting the average power of the first laser pulse train to be greater than the average power of the second laser pulse train, the output energy of the two laser pulse trains can be configured differently, which is beneficial to adapt to the process requirements of different modification processes.

[0033] The first laser pulse train is mainly used to construct a through-hole or semi-through-hole main modification channel inside the glass substrate. The high average power provides sufficient laser energy, effectively ensuring the continuity and structural integrity of the modification area in the thickness direction of the substrate, and avoiding problems such as breakage or insufficient modification in the initial modification channel. The second laser pulse train only performs local reinforcement and etching rate compensation for the modification area at each depth position. It does not require excessively high laser energy. Selective modification compensation can be achieved by using a low power configuration. While ensuring the hole shape correction effect, it achieves precise matching and synergistic optimization of the two-stage laser modification process.

[0034] To further explain, in step B, the average power of the first laser pulse train is 0.3 to 50 W.

[0035] This effectively prevents excessive energy from causing over-expansion or even microcracks in the first modified region, thus affecting the final quality and smoothness of the pore wall.

[0036] It should be noted that, under the condition that the focusing optical parameters remain unchanged, the theoretical geometric dimensions of the laser focal point are not affected by the average power of the first laser pulse train; however, as the average power of the first laser pulse train increases, the light intensity at the focal point increases, thereby increasing the lateral dimension of the actual modified region formed within the glass substrate. Therefore, in actual operation, this scheme can adjust the average power of the first laser pulse train according to the aperture of the final aperture shape; however, this scheme is not limited to this.

[0037] To further explain, in step C, the average power of the second laser pulse train increases from the upper surface of the glass substrate to the lower surface of the glass substrate; And / or, the number of scans of the second laser pulse train increases from the upper surface of the glass substrate to the lower surface of the glass substrate.

[0038] In another preferred embodiment of this technical solution, the process parameters of the second laser pulse train are set in a gradient manner, so that the average power of the second laser pulse train gradually increases from the upper surface to the lower surface of the glass substrate, and / or the number of scans of the second laser pulse train gradually increases from the upper surface to the lower surface of the glass substrate. Addressing the problem of uneven longitudinal etching rates caused by concentration attenuation and limited mass transfer in the depth direction of the etching solution during wet etching, this invention provides differentiated reinforcement modification to the second modified regions at different depths. This allows the deeper the second modified region of the glass substrate, the higher the degree of laser modification, matching the gradually decreasing etching efficiency in the depth direction. This effectively compensates for the differences in longitudinal etching rates, helps to balance the etching removal rate at various points along the axial direction of the glass via, further eliminates channel taper, and improves the regularity and consistency of the hole shape.

[0039] To further explain, in step C, the average power of the second laser pulse train is 0.2 to 30 W.

[0040] This effectively prevents excessive power from creating overly large modified areas at local depths, which could lead to excessive corrosion during subsequent etching processes.

[0041] To further illustrate, multiple second modified regions are uniformly distributed along the thickness direction of the glass substrate.

[0042] This facilitates precise alignment of the laser focus and programmed scanning, reducing laser positioning deviations and the difficulty of process debugging. Simultaneously, the uniformly distributed modified areas allow for a more balanced etching rate compensation effect in the thickness direction, improving overall processing consistency, simplifying mass production processes, and effectively enhancing the fabrication accuracy and process feasibility of glass vias.

[0043] It should be noted that uniform distribution means that the intervals between multiple second-modification regions are equal.

[0044] To further explain, in step B, the focal diameter of the first laser pulse train is less than or equal to the diameter of the glass via. When the glass via is a glass through-hole, the preset depth is equal to the depth of the glass through-hole; When the glass via is a blind glass via, the preset depth is less than or equal to the depth of the blind glass via.

[0045] In a more preferred embodiment of this technical solution, the focal diameter of the first laser pulse train is limited to be less than or equal to the final formed glass via diameter, and corresponding laser modification preset depths are matched for through holes and blind holes respectively.

[0046] Because the glass substrate itself has inherently weak etching characteristics in the etching solution, only the laser-modified area has an efficient etching removal effect. If the laser focal diameter is larger than the target aperture, the lateral range of the first modified region inside the substrate is easily too large, which can easily lead to aperture deviation and oversized apertures after subsequent etching. If the aperture size is forcibly controlled by shortening the etching time, it may result in the presence of an incompletely etched first modified region inside the substrate. The glass structure of this residual modified region is loose and the aperture wall is rough, which may affect the bonding quality and filling integrity of the subsequent metal electroplating filling process, thereby reducing the conductivity of the via and the reliability of the package.

[0047] This approach, by further limiting the focal point size and modification depth, can effectively avoid the problems of excessive expansion of the first modification region and modification residue, ensuring the aperture accuracy and wall quality of the glass vias, and providing a good process foundation for the subsequent metallization fabrication of high-performance interconnect structures.

[0048] To further explain, in step C, the scanning area of ​​the second laser pulse train in any of the second modified regions is less than or equal to the cross-sectional area of ​​the glass via.

[0049] In another preferred embodiment of this technical solution, the scanning area of ​​the second laser pulse train in any second modified region is limited to less than or equal to the cross-sectional area of ​​the glass via, so that the reinforcement modification is only implemented within the outline of the target via, and the etching rate in the depth direction is only specifically controlled, avoiding the formation of redundant modified regions outside the first modified region, which would cause lateral over-etching and aperture deviation. While achieving channel taper compensation, the aperture accuracy and hole shape regularity of the formed glass via are guaranteed.

[0050] To further clarify, in step A, the thickness of the glass substrate is 1 to 1000 μm, and the glass substrate is any one of quartz glass, borosilicate glass, aluminosilicate glass, soda-lime glass, phosphate glass, and borosilicate glass. In step B, the first laser pulse train is a femtosecond laser or a picosecond laser with a wavelength of 700–1500 nm; When the first laser pulse train is a femtosecond laser, the pulse width is 10 to 600 fs; When the first laser pulse train is a picosecond laser, the pulse width is 10 to 800 ps; In step C, the second laser pulse train is a femtosecond laser or a picosecond laser with a wavelength of 700–1500 nm; When the second laser pulse train is a femtosecond laser, the pulse width is 10–600 fs; When the second laser pulse train is a picosecond laser, the pulse width is 10–800 ps; In step D, the etching solution is either a hydrofluoric acid solution or a potassium hydroxide solution.

[0051] Furthermore, the taper of the glass via is less than 0.1°.

[0052] This method can produce low-tapered glass vias with a taper of less than 0.1°. The low taper ensures uniform radial dimensions of the channel, which is beneficial for the uniformity of electroplating filling and improves the high-frequency signal transmission characteristics.

[0053] The present invention will be further illustrated below through specific embodiments: Example 1 A. Prepare a borosilicate glass substrate with a thickness of 200μm. Use acetone, anhydrous ethanol and deionized water to ultrasonically clean the substrate for 15 min in sequence to remove surface contaminants. Then place it in an oven to dry and cool to room temperature.

[0054] B. Focus a first laser pulse train parallel to the thickness direction of the glass substrate onto the upper surface of the glass substrate, moving the focal point of the first laser pulse train 200 μm along the thickness direction of the glass substrate to form a first modified region, such as... Figure 1 As shown; in, The first laser pulse train has a pulse width of 10 ps, ​​a wavelength of 1064 nm, an average power of 1 W, a repetition frequency of 50 kHz, and a scanning speed of 2 mm / s.

[0055] C. Divide the first modified region into two equal second modified regions along the thickness direction of the glass substrate. Focus a second laser pulse train onto each of the two second modified regions for scanning, forming two compensation modified regions, such as... Figure 1 As shown; in, The second laser pulse train has a pulse width of 10 ps, ​​a wavelength of 1064 nm, a repetition frequency of 50 kHz, and a scanning speed of 2 mm / s. When the depth of the second modified region is 67 μm, the average power of the second laser pulse train is 0.6 W; When the depth of the second modified region is 133 μm, the average power of the second laser pulse train is 0.8 W.

[0056] D. The glass substrate is immersed in a 10wt% potassium hydroxide solution and wet-etched at 40°C for 60 minutes to obtain a glass through-hole. The diameter of the glass through-hole is 35μm, the aspect ratio is 5.7:1, and the taper is less than 0.08°.

[0057] Example 2 A. Prepare a borosilicate glass substrate with a thickness of 1000μm. Use acetone, anhydrous ethanol and deionized water to ultrasonically clean the substrate for 15 min in sequence to remove surface contaminants. Then place it in an oven to dry and cool to room temperature.

[0058] B. Focus a first laser pulse train parallel to the thickness direction of the glass substrate onto the upper surface of the glass substrate, so that the focal point formed by the first laser pulse train moves 1000μm along the thickness direction of the glass substrate to form a first modified region. in, The first laser pulse train has a pulse width of 410 fs, a wavelength of 1035 nm, an average power of 0.39 W, a repetition frequency of 20 kHz, and a scanning speed of 1 mm / s.

[0059] C. Divide the first modified region into four equal second modified regions along the thickness direction of the glass substrate, and focus the second laser pulse train on the four second modified regions respectively to scan, forming four compensation modified regions. in, The second laser pulse train has a pulse width of 410 fs, a wavelength of 1035 nm, a repetition frequency of 20 kHz, and a scanning speed of 1 mm / s. When the depth of the second modified region is 200 μm, the average power of the second laser pulse train is 0.29 W; When the depth of the second modified region is 400 μm, the average power of the second laser pulse train is 0.31 W; When the depth of the second modified region is 600 μm, the average power of the second laser pulse train is 0.33 W; When the depth of the second modified region is 800 μm, the average power of the second laser pulse train is 0.35 W.

[0060] D. The glass substrate is immersed in a 5 wt% hydrofluoric acid solution and wet-etched for 120 min at room temperature to obtain a glass through-hole. The diameter of the glass through-hole is 60 μm, the aspect ratio is 16.7:1, and the taper is less than 0.03°.

[0061] Example 3 A. Prepare a borosilicate glass substrate with a thickness of 300μm. Use acetone, anhydrous ethanol and deionized water to ultrasonically clean the substrate for 15 min in sequence to remove surface contaminants. Then place it in an oven to dry and cool to room temperature.

[0062] B. Focus a first laser pulse train parallel to the thickness direction of the glass substrate onto the upper surface of the glass substrate, moving the focal point of the first laser pulse train 240 μm along the thickness direction of the glass substrate to form a first modified region, such as... Figure 2 As shown; in, The first laser pulse train has a pulse width of 390 fs, a wavelength of 1030 nm, an average power of 0.3 W, a repetition frequency of 25 kHz, and a scanning speed of 1.5 mm / s.

[0063] C. Divide the first modified region into two second modified regions along the thickness direction of the glass substrate, and focus a second laser pulse train onto each of the two second modified regions for scanning, forming two compensated modified regions, such as... Figure 2 As shown; in, The second laser pulse train has a pulse width of 390 fs, a wavelength of 1030 nm, a repetition frequency of 50 kHz, and a scanning speed of 1.5 mm / s. When the depth of the second modified region is 100 μm, the average power of the second laser pulse train is 0.21 W; When the depth of the second modified region is 200 μm, the average power of the second laser pulse train is 0.23 W.

[0064] D. The glass substrate is immersed in a 5 wt% hydrofluoric acid solution and wet-etched for 80 min at room temperature to obtain a glass blind hole. The glass blind hole has a diameter of 40 μm, a depth of 240 μm, a depth-to-diameter ratio of 6:1, and a taper of less than 0.03°.

[0065] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the present invention.

Claims

1. A method for preparing a glass via, characterized in that, Includes the following steps: A. Provide glass substrates; B. Focus a first laser pulse train parallel to the thickness direction of the glass substrate onto the upper surface of the glass substrate, and move the focal point formed by the first laser pulse train along the thickness direction of the glass substrate to a predetermined depth to form a first modified region. C. According to the preset depth position, the first modified region is divided into multiple second modified regions along the thickness direction of the glass substrate. The second laser pulse train is focused on the second modified region for scanning. According to the depth position corresponding to the second modified region, the scanning parameters of the second laser pulse train are adjusted accordingly to form multiple compensated modified regions. D. Immerse the glass substrate in an etching solution, and after etching, a glass via is formed; The glass vias include at least through holes and blind holes.

2. The method for preparing a glass via according to claim 1, characterized in that, The average power of the first laser pulse train is greater than the average power of the second laser pulse train.

3. The method for preparing a glass via according to claim 1, characterized in that, In step B, the average power of the first laser pulse train is 0.3 to 50 W.

4. The method for preparing a glass via according to claim 1, characterized in that, In step C, the average power of the second laser pulse train increases from the upper surface of the glass substrate to the lower surface of the glass substrate; And / or, the number of scans of the second laser pulse train increases from the upper surface of the glass substrate to the lower surface of the glass substrate.

5. The method for preparing a glass via according to claim 4, characterized in that, In step C, the average power of the second laser pulse train is 0.2 to 30 W.

6. The method for preparing a glass via according to claim 1, characterized in that, Multiple second modified regions are uniformly distributed along the thickness direction of the glass substrate.

7. The method for preparing a glass via according to claim 1, characterized in that, In step B, the focal diameter of the first laser pulse train is less than or equal to the diameter of the glass via. When the glass via is a glass through-hole, the preset depth is equal to the depth of the glass through-hole; When the glass via is a blind glass via, the preset depth is less than or equal to the depth of the blind glass via.

8. The method for preparing a glass via according to claim 1, characterized in that, In step C, the scanning area of ​​the second laser pulse train in any of the second modified regions is less than or equal to the cross-sectional area of ​​the glass via.

9. The method for preparing a glass via according to claim 1, characterized in that, In step A, the thickness of the glass substrate is 1 to 1000 μm, and the glass substrate is any one of quartz glass, borosilicate glass, aluminosilicate glass, soda-lime glass, phosphate glass, and borosilicate glass. In step B, the first laser pulse train is a femtosecond laser or a picosecond laser with a wavelength of 700–1500 nm; When the first laser pulse train is a femtosecond laser, the pulse width is 10 to 600 fs; When the first laser pulse train is a picosecond laser, the pulse width is 10 to 800 ps; In step C, the second laser pulse train is a femtosecond laser or a picosecond laser with a wavelength of 700–1500 nm; When the second laser pulse train is a femtosecond laser, the pulse width is 10–600 fs; When the second laser pulse train is a picosecond laser, the pulse width is 10–800 ps; In step D, the etching solution is either a hydrofluoric acid solution or a potassium hydroxide solution.

10. The method for preparing a glass via according to claim 1, characterized in that, The taper of the glass through-hole is less than 0.1°.

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