Glass ceramic and laser processing method thereof

Abstract

The invention provides microcrystalline glass and a laser processing method thereof. The laser processing method of the microcrystalline glass comprises the following steps: irradiating a target area of a microcrystalline glass substrate soaked in an alkaline solution by adopting a target laser beam; after irradiation of the target laser beam, a glass through hole penetrating through the thickness direction of the target area is formed in the target area of the microcrystalline glass substrate. The glass ceramic finished product with the glass through hole, which is prepared by the laser processing method of the glass ceramic, achieves the purpose of high-precision and high-efficiency processing of the glass through hole.

Description

Technical Field

[0001] This application relates to the field of laser processing technology for microcrystalline glass, and particularly to a microcrystalline glass and a laser processing method thereof. Background Technology

[0002] Glass, with its adjustable coefficient of thermal expansion and low dielectric constant, is considered an ideal choice for overcoming performance bottlenecks in next-generation advanced packaging and replacing silicon-based materials. Microcrystalline glass, in particular, has significantly improved toughness through special processes, resulting in a substantial increase in reliability. However, traditional laser ablation or mechanical cutting processes for creating glass vias in microcrystalline glass introduce stress defects during the via fabrication process. Furthermore, these processes often produce vias with relatively rough walls, making it difficult to meet the demands of advanced packaging. Summary of the Invention

[0003] This application provides a microcrystalline glass and a laser processing method thereof to solve the problem of large roughness of glass through holes on microcrystalline glass in related technologies.

[0004] To achieve the above objectives, the technical solution adopted in this application is as follows: In a first aspect, embodiments of this application provide a laser processing method for microcrystalline glass, comprising the following steps: A target laser beam is used to irradiate the target area of ​​a microcrystalline glass substrate immersed in an alkaline solution; After being irradiated by the target laser beam, a glass through-hole penetrating the thickness direction is formed in the target area of ​​the microcrystalline glass substrate.

[0005] In some possible implementations, prior to irradiating the target area of ​​the microcrystalline glass substrate immersed in the alkaline solution with the target laser beam, the method further includes: The microcrystalline glass substrate is immersed in an alkaline solution, and the liquid level of the alkaline solution is adjusted until the difference between the liquid level and the height of the upper surface of the microcrystalline glass substrate is greater than or equal to a preset distance.

[0006] In some feasible ways, the target laser beam is a Gaussian laser beam, a femtosecond Bessel beam, or a flat-top beam.

[0007] In some feasible implementations, the target laser beam is a femtosecond Bessel beam; the formation of a through-hole penetrating the thickness direction in the target region of the microcrystalline glass substrate after irradiation by the target laser beam includes: After being irradiated by the target laser beam, a modified region with a high aspect ratio is induced to form at the target region location on the microcrystalline glass substrate; The modified region is selectively etched away in the alkaline solution to form the glass via that penetrates the microcrystalline glass substrate.

[0008] In some feasible implementations, the center wavelength of the femtosecond Bessel beam is 515 nm or 1030 nm, the pulse width is 10 fs-1000 fs, and the bottom angle of the conical lens is 0.5°-10°.

[0009] In some feasible embodiments, the target laser beam irradiates the microcrystalline glass substrate for 10-15 hours, the alkaline solution is at room temperature, and the modified region is at 100°C-130°C.

[0010] In some feasible embodiments, the alkaline solution is a sodium hydroxide or potassium hydroxide solution that is saturated at room temperature.

[0011] In some feasible embodiments, the diameter of the glass via is 50 μm-70 μm; and / or, the waist-to-diameter ratio of the glass via is greater than or equal to 80%.

[0012] In some feasible embodiments, the thickness of the microcrystalline glass substrate ranges from 100 μm to 1100 μm.

[0013] Secondly, embodiments of this application also provide a microcrystalline glass, which is obtained by the laser processing method for microcrystalline glass as described in the first aspect above.

[0014] The beneficial effects of the laser processing method for microcrystalline glass provided in this application are as follows: This application uses a target laser beam to irradiate the target area of ​​a microcrystalline glass substrate immersed in an alkaline solution. After irradiation by the target laser beam, a glass via penetrating the thickness direction is formed in the target area of ​​the microcrystalline glass substrate. When the target laser beam irradiates the surface of the microcrystalline glass substrate through the alkaline solution, the temperature of the target area of ​​the microcrystalline glass substrate irradiated by the target laser beam and the alkaline solution increases, accelerating the dissolution of the target area of ​​the microcrystalline glass substrate and the alkaline solution and etching of the microcrystalline glass substrate, thereby rapidly forming a glass via penetrating the microcrystalline glass substrate in the target area. At the same time, the microcrystalline glass... In areas of the glass substrate other than the target area, especially those farther from the vias, the alkaline solution remains at a lower temperature because it is not irradiated by the target laser beam. This means that if the glass-ceramic substrate is immersed in a room-temperature alkaline solution, the target area will reach a locally high temperature upon laser irradiation, forming vias and minimizing the impact on other areas. This significantly improves the smoothness of the via walls, meeting the high requirements of advanced packaging, and also significantly increases the processing efficiency of forming vias on the glass-ceramic substrate. This achieves both high precision and high efficiency in processing vias on the glass-ceramic substrate. Consequently, the laser processing method for glass-ceramics described above produces finished products with vias that achieve both high precision and high efficiency in processing the vias. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A flowchart illustrating a laser processing method for microcrystalline glass provided in some embodiments of this application; Figure 2 for Figure 1 Flowchart of step S200; Figure 3 for Figure 1 A flowchart illustrating one possible method for laser processing of microcrystalline glass; Figure 4 A flowchart of a laser processing method for microcrystalline glass provided in other embodiments of this application. Detailed Implementation

[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0019] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation", "connection" and "joining" should be interpreted broadly, for example, as fixed connection, detachable connection, or integral connection; those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0020] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more, unless otherwise explicitly specified.

[0021] Glass, with its adjustable coefficient of thermal expansion and low dielectric constant, is considered an ideal choice for overcoming performance bottlenecks in next-generation advanced packaging and replacing silicon-based materials. Microcrystalline glass, in particular, through special processes, significantly improves its toughness, resulting in a substantial increase in its reliability.

[0022] Microcrystalline glass is an advanced inorganic non-metallic material that combines the properties of glass and ceramics. It is produced by precisely controlling the crystallization (crystallization) of a base glass with a specific composition, forming a polycrystalline solid with a large number of tiny crystals uniformly distributed within the residual glass phase. It's like an upgraded material obtained by internally "growing" countless tiny crystals from glass. Due to the presence of numerous tiny crystals, microcrystalline glass has significantly higher strength and hardness than ordinary glass, and is also hard and wear-resistant, exhibiting high mechanical strength and hardness. Simultaneously, its coefficient of thermal expansion can be adjusted within a wide range, even allowing for the fabrication of zero-expansion materials, enabling it to withstand drastic temperature changes (good thermal shock resistance) and high operating temperatures, thus possessing excellent thermal properties. Furthermore, it is corrosion-resistant, does not release harmful substances, and has good chemical stability. In summary, due to its adjustable and excellent properties, microcrystalline glass has a wide range of applications, especially in precision manufacturing.

[0023] However, due to the high hardness and brittleness of glass-ceramics, traditional mechanical cutting processes for creating through-holes in glass-ceramics are prone to microcracks and edge breakage, resulting in low yields and difficulty in achieving high-precision microstructure processing. In recent years, femtosecond laser / ultrafast laser processing technology has provided a new solution for the precision processing of glass-ceramics due to its unique advantages of ultra-short pulse width and ultra-high peak power. The principle is to utilize the thermal effect or nonlinear absorption of lasers to induce localized crystallization within or on the surface of the glass-ceramic substrate, altering its local properties. This allows for direct drilling and cutting on the substrate. However, simple laser modification and ablation may create heat-affected zones or recast layers. Since there is a significant difference in etching rates between laser-modified and unmodified areas (usually the modified area etches faster), the current mainstream precision processing method combines laser processing with chemical etching to selectively remove micropores or channels, thereby improving the yield of glass-ceramics. However, while high aspect ratio glass vias can be obtained, the roughness of the via walls is still relatively high, which cannot meet the requirements of advanced packaging.

[0024] In order to reduce the roughness of the hole walls of glass through holes on glass-ceramic glass, that is, to improve the processing accuracy of glass through holes on glass-ceramic glass, embodiments of this application provide a laser processing method for glass-ceramic glass.

[0025] refer to Figure 1 Laser processing methods for microcrystalline glass include: Step S100: Irradiate the target area of ​​the microcrystalline glass substrate immersed in the alkaline solution using a target laser beam.

[0026] The aforementioned microcrystalline glass substrate refers to the microcrystalline glass to be processed. The aforementioned target area refers to the location where glass vias need to be formed on the microcrystalline glass.

[0027] The alkaline solution described above may be, but is not limited to, a sodium hydroxide or potassium hydroxide solution. This alkaline solution is saturated at room temperature; that is, in one feasible manner, the alkaline solution may be saturated sodium hydroxide. Here, saturation refers to the fact that the mass fraction of sodium hydroxide in the alkaline solution is 50%-55%, and the molar concentration of sodium hydroxide in the alkaline solution is 26.0-27.0 mol / L.

[0028] It should be noted that, in this embodiment, during the laser processing of the microcrystalline glass, the temperature of the alkaline solution is room temperature, for example, but not limited to, 25°C. That is, the alkaline solution is saturated at 25°C.

[0029] In another feasible approach, the alkaline solution can also be a saturated potassium hydroxide solution with a potassium hydroxide mass fraction of 50%-55% and a potassium hydroxide molar concentration of 26.0-27.0 mol / L.

[0030] Before step S100 above, the glass-ceramic substrate needs to be pretreated by immersing it in an alkaline solution. Specifically, after immersing the glass-ceramic substrate in the alkaline solution, the level of the solution must be higher than the upper surface of the substrate to ensure complete immersion.

[0031] In this embodiment, when the glass-ceramic substrate is placed in an alkaline solution at room temperature, the alkaline solution will not react with the glass-ceramic substrate. Only when the temperature of the alkaline solution reaches above 90°C will it react with the glass-ceramic substrate to form a through-hole. Therefore, the purpose of the target laser beam used in step S100 is to increase the temperature of the alkaline solution in the target area of ​​the glass-ceramic substrate, creating a localized high-temperature environment.

[0032] The target laser beam can be a Gaussian laser beam, a femtosecond Bessel beam, or a flat-top beam.

[0033] In one feasible approach, the target laser beam can be a Gaussian laser beam, referring to a laser beam directly emitted by a conventional laser. In laser physics and engineering applications, unless otherwise specified (e.g., using a special aperture or fiber shaping), we assume the laser energy distribution discussed is Gaussian. The intensity of a Gaussian laser beam is strongest in the center and smoothly decreases towards both sides, with its cross-sectional energy distribution exhibiting a bell-shaped curve (mathematically known as a Gaussian function). The high energy at the center of a Gaussian beam easily creates a deep-center, shallow-edge aperture (conical aperture). This is commonly used for processing microcrystalline glass substrates with a thickness of approximately 100 μm. If a flat-bottomed aperture or a specific taper is required, it may be necessary to adjust the defocus (placing the glass surface above or below the focal point) and utilize different beam cross-sectional shapes for processing.

[0034] In another feasible approach, the target laser beam can also be a femtosecond Bessel beam or a flat-top beam. These femtosecond Bessel beams and flat-top beams can be collectively referred to as shaping beams. That is, shaping a laser beam differs from a conventional laser beam; it involves shaping the laser beam along or perpendicular to the optical axis. The femtosecond Bessel beam is elongated at the center and exhibits no diffraction. Using a femtosecond Bessel beam, glass vias with extremely high depth-to-depth ratios can be obtained. Femtosecond Bessel beams are suitable for forming high-precision glass vias on relatively thick microcrystalline glass substrates.

[0035] The center wavelength of the aforementioned femtosecond Bessel beam is 515nm or 1030nm, the pulse width is 10fs-1000fs, and the bottom angle of the conical lens is 0.5°-10°.

[0036] When the thickness of the glass-ceramic substrate is greater than 100μm, for example, the thickness of the glass-ceramic substrate is 100μm, 110μm, 120μm, ... 150μm, ... 200μm, ... 300μm, 400μm, ... or the thickness of the glass-ceramic substrate is much greater than 100μm, such as 500μm, 510μm, 530μm, 540μm, 550μm, ... 600μm, ... 800μm, ... 900μm, ... 1000μm, or even 1100μm, the target laser beam cannot meet the requirements using a Gaussian laser beam. When the thickness of the glass-ceramic substrate is between 500μm and 1100μm, the target laser beam needs to use a femtosecond Bessel laser beam.

[0037] In addition, in another feasible approach, the aforementioned target laser beam can also be a flat-top beam that is evenly distributed, with the edges of the glass through-hole formed by the flat-top beam being neat and the bottom of the glass through-hole being flat.

[0038] After step S100, step S200 is also included: after being irradiated by the target laser beam, a glass through-hole penetrating the thickness direction is formed in the target area of ​​the microcrystalline glass substrate.

[0039] When the target laser beam irradiates the surface of the glass-ceramic through an alkaline solution, the solvent in the alkaline solution only reacts chemically with the glass at the local high-temperature location, i.e., the target area, efficiently destroying the structure of the glass-ceramic to form a glass via through the glass-ceramic substrate. The thickness of the entire glass-ceramic substrate remains unchanged, and the diameter of the glass via depends on the diameter of the target laser beam, resulting in a very small taper of the via wall. At the same time, the subtractive material mechanism is chemical etching, which does not introduce additional stress. Chemical etching makes the wall roughness of the glass via extremely good.

[0040] This application employs a target laser beam to irradiate a target area of ​​a microcrystalline glass substrate immersed in an alkaline solution. After irradiation, a glass via penetrating the thickness direction is formed in the target area of ​​the microcrystalline glass substrate. Through the above steps, when the target laser beam penetrates the alkaline solution and irradiates the surface of the microcrystalline glass, the temperature of the target area of ​​the microcrystalline glass substrate and the alkaline solution increases, accelerating the dissolution of the target area of ​​the microcrystalline glass substrate and the alkaline solution, and etching the microcrystalline glass substrate. This rapidly forms a glass via penetrating the microcrystalline glass substrate in the target area, thus greatly improving the processing efficiency of the glass via. At the same time, other areas of the microcrystalline glass substrate besides the target area, especially those closer to the glass via, are also irradiated. In distant areas, the alkaline solution remains at a lower temperature because it is not irradiated by the target laser beam. This means that if the microcrystalline glass substrate is immersed in an alkaline solution at room temperature, the target area of ​​the microcrystalline glass substrate will experience localized high temperatures upon irradiation by the target laser beam, forming glass vias and reducing the impact on other areas. This not only significantly improves the smoothness of the via walls on the microcrystalline glass, meeting the high requirements of advanced packaging, but also significantly increases the processing efficiency of forming glass vias on the microcrystalline glass. This achieves both high precision and high efficiency in processing glass vias on the microcrystalline glass substrate, resulting in microcrystalline glass products with glass vias manufactured using the aforementioned laser processing method that achieve both high precision and high efficiency in processing the glass vias.

[0041] The following explanation uses a microcrystalline glass substrate with a thickness of 500μm-1100μm and a femtosecond Bessel beam as the target laser beam as an example.

[0042] refer to Figure 2 In some feasible implementations, step S200 above, which involves forming a through-hole in the thickness direction of a microcrystalline glass substrate after irradiation by a target laser beam, includes: Step S210: After being irradiated by the target laser beam, a modified region with a high aspect ratio is induced to form at the target area of ​​the microcrystalline glass substrate.

[0043] Following S210 above, step S220 is also included: the modified region is selectively etched away in an alkaline solution to form a glass via penetrating the microcrystalline glass substrate.

[0044] After steps S210-S220, when the target laser beam irradiates the surface of the glass-ceramic through the alkaline solution, the solvent in the alkaline solution only reacts chemically with the glass at the local high-temperature location, i.e., the target area, efficiently destroying the structure of the glass-ceramic to form a glass via through the glass-ceramic substrate. The thickness of the entire glass-ceramic substrate remains unchanged, and the diameter of the glass via depends on the diameter of the target laser beam, resulting in a very small taper of the glass via wall. At the same time, the subtractive material mechanism is chemical etching removal, which does not introduce additional stress. Chemical etching makes the roughness of the glass via wall excellent.

[0045] refer to Figure 3 In some feasible implementations, before step S100: irradiating the target area of ​​the microcrystalline glass substrate immersed in the alkaline solution with a target laser beam, step S010 is further included: The microcrystalline glass substrate is immersed in an alkaline solution, and the liquid level of the alkaline solution is adjusted until the difference between the liquid level and the height of the upper surface of the microcrystalline glass substrate is greater than or equal to a preset distance.

[0046] Step S010 above is a preprocessing step.

[0047] In step S010 above, the alkaline solution is of particular importance.

[0048] The alkaline solution in the embodiments of this application may be, but is not limited to, a sodium hydroxide or potassium hydroxide solution. This alkaline solution is saturated at room temperature; that is, in one feasible manner, the alkaline solution may be saturated sodium hydroxide. Here, saturation refers to the fact that the mass fraction of sodium hydroxide in the alkaline solution is 50%-55%, and the molar concentration of sodium hydroxide in the alkaline solution is 26.0-27.0 mol / L.

[0049] It should be noted that, in this embodiment, during the laser processing of the microcrystalline glass, the temperature of the alkaline solution is room temperature, for example, but not limited to, 25°C. That is, the alkaline solution is saturated at 25°C.

[0050] In another feasible approach, the alkaline solution can also be a saturated potassium hydroxide solution, with a potassium hydroxide mass fraction of 50%-55% and a potassium hydroxide molar concentration of 26.0-27.0 mol / L. That is, the mass fraction and molar concentration of the alkaline solution in the embodiments of this application must meet the above-mentioned ranges.

[0051] Through numerous experiments, it was found that besides the alkaline solution itself needing to meet the aforementioned parameters, the liquid level of the alkaline solution is also a crucial parameter. Specifically, the difference between the liquid level of the alkaline solution and the height of the upper surface of the microcrystalline glass substrate must be greater than or equal to a preset distance. This preset distance directly affects the transmission of the target laser beam. This preset distance is not arbitrarily chosen but requires a comprehensive trade-off between laser transmission efficiency and processing stability. This preset distance represents the "golden range" for generating stable, high-energy laser beams.

[0052] The difference between the liquid level of the alkaline solution and the height of the upper surface of the microcrystalline glass substrate is greater than or equal to a preset distance. Through multiple experiments, it was found that this preset distance can be 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, ..., 20mm, ..., 30mm, ..., 35mm, ..., 40mm, ..., 48mm, 49mm, or 50mm. When the difference between the liquid level of the alkaline solution and the height of the upper surface of the microcrystalline glass substrate is greater than or equal to the preset distance, and this preset distance is between 10mm and 50mm, it not only ensures that the target laser beam can bring the alkaline solution in the target area (i.e., the modified area) to the preset value, but also that the diameter of the target laser beam meets the requirements.

[0053] In some feasible methods, the target laser beam irradiates the microcrystalline glass substrate for 10-15 hours, the alkaline solution is at room temperature, and the temperature of the modified region is 100℃-130℃.

[0054] In other words, after step S010 above, and through multiple experiments, it was determined that the duration of irradiation of the microcrystalline glass substrate by the target laser beam is 10-15 hours, and the temperature of the alkaline solution is room temperature. Specifically, the microcrystalline glass substrate is immersed in an alkaline solution at room temperature. Before irradiation by the target laser beam, both the microcrystalline glass substrate and the alkaline solution are at room temperature. The target area of ​​the microcrystalline glass substrate is then irradiated by the target laser beam. After 10-15 hours, the irradiated area undergoes modification, forming a modified area. At this point, the temperature of the modified area is 100℃-130℃. This localized high temperature in the target area allows for high precision in the processing position of the glass vias in the microcrystalline glass substrate, a small internal locally induced high-temperature plasma thermally affected area, and controllable processing morphology.

[0055] It should be noted that the above conditions are set for a microcrystalline glass substrate thickness of 500μm-1100μm, a femtosecond Bessel beam as the target laser beam, and a glass via diameter of 50μm-70μm. Specifically, the duration of the target laser beam irradiation on the microcrystalline glass substrate and the temperature of the modified region need to be determined in conjunction with the thickness of the microcrystalline substrate and the diameter of the glass via, and are not specifically limited here.

[0056] It should be noted that, theoretically, when a femtosecond Bessel beam is used as the target laser beam to irradiate a glass-ceramic substrate, the diameter of all glass vias should be equal, and the glass vias should be cylindrical in shape. However, in reality, the diameter of the end faces of the glass vias in the thickness direction of the glass-ceramic substrate is larger than the diameter of the middle face, and the two end faces are equal in diameter, similar to an hourglass structure.

[0057] After the above steps, the target laser beam adopts a femtosecond Bessel beam, which enables the formation of glass vias with a diameter of 50μm-70μm on a glass-ceramic substrate with a thickness of 500μm-1100μm, an irradiation time of 10-15 hours, and an alkaline solution temperature of room temperature. The glass vias have a waist-to-diameter ratio greater than or equal to 80%.

[0058] The waist-to-diameter ratio mentioned above refers to the ratio of the midpoint diameter of the glass via in the thickness direction of the glass-ceramic substrate to the diameter of the end face located at the end face. The larger the waist-to-diameter ratio, the closer the glass via made on the glass-ceramic substrate is to the theoretical cylindrical shape, the smaller the taper of the hole wall, and the higher the precision.

[0059] To address the aforementioned problems, this application also provides a laser processing method for microcrystalline glass, as described above. Figure 4 Laser processing methods for microcrystalline glass include: Step S001: Immerse the microcrystalline glass substrate in an alkaline solution, adjusting the liquid level until the difference between the liquid level and the height of the upper surface of the microcrystalline glass substrate is greater than or equal to a preset distance. This step S001 is a pretreatment step. That is, before processing the glass through-holes on the microcrystalline glass substrate, it needs to be pretreated by immersing it in an alkaline solution. Specifically, after immersing the microcrystalline glass substrate in the alkaline solution, the liquid level of the alkaline solution must be higher than the upper surface of the microcrystalline glass substrate to ensure that the microcrystalline glass substrate is completely immersed in the alkaline solution.

[0060] Meanwhile, after immersing the microcrystalline glass substrate in the alkaline solution, it is also necessary to adjust the liquid level of the alkaline solution until the difference between the liquid level and the height of the upper surface of the microcrystalline glass substrate is greater than or equal to a preset distance.

[0061] The alkaline solution in the embodiments of this application is saturated sodium hydroxide.

[0062] The aforementioned saturated sodium hydroxide refers to an alkaline solution with a sodium hydroxide mass fraction of 50%-55% and a sodium hydroxide molar concentration of 26.0-27.0 mol / L. The temperature of the alkaline solution is room temperature.

[0063] Through numerous experiments, it was found that besides the alkaline solution itself needing to meet the aforementioned parameters, the liquid level of the alkaline solution is also a crucial parameter. Specifically, the difference between the liquid level of the alkaline solution and the height of the upper surface of the microcrystalline glass substrate must be greater than or equal to a preset distance. This preset distance directly affects the transmission of the target laser beam. This preset distance is not arbitrarily chosen but requires a comprehensive trade-off between laser transmission efficiency and processing stability. This preset distance represents the "golden range" for generating stable, high-energy laser beams.

[0064] The difference between the liquid level of the alkaline solution and the height of the upper surface of the microcrystalline glass substrate is greater than or equal to a preset distance. After multiple tests, it was found that this preset distance is 10mm-50mm. When the difference between the liquid level of the alkaline solution and the height of the upper surface of the microcrystalline glass substrate is greater than or equal to the preset distance, and this preset distance meets the requirements of 10mm-50mm, the size and accuracy requirements of the glass through-hole can be met.

[0065] Following step S001, step S002 is also included: using a target laser beam to irradiate the target area of ​​the microcrystalline glass substrate immersed in an alkaline solution.

[0066] In this embodiment, the target laser beam is a femtosecond Bessel beam with a center wavelength of 515 nm or 1030 nm, a pulse width of 10 fs to 1000 fs, and a cone lens bottom angle of 0.5° to 10°. The duration of irradiation of the microcrystalline glass substrate by the target laser beam is 10 to 15 hours, the temperature of the alkaline solution is room temperature, and the temperature of the modified region is 100°C to 130°C.

[0067] Following step S002, step S003 is also included: after being irradiated by the target laser beam, a modified region with a high aspect ratio is induced to form at the target area location of the microcrystalline glass substrate.

[0068] Following S003 above, step S004 is also included: the modified region is selectively etched away in an alkaline solution to form a glass via penetrating the microcrystalline glass substrate.

[0069] After the above steps S001-S004, when the target laser beam irradiates the surface of the glass-ceramic through the alkaline solution, the solvent in the alkaline solution only reacts chemically with the glass at the local high-temperature location, i.e., the target area, efficiently destroying the structure of the glass-ceramic to form a glass via through the glass-ceramic substrate. The thickness of the entire glass-ceramic substrate remains unchanged, and the diameter of the glass via depends on the diameter of the target laser beam, resulting in a very small taper of the glass via wall. At the same time, the subtractive material mechanism is chemical etching removal, which does not introduce additional stress. Chemical etching makes the roughness of the glass via wall extremely good.

[0070] This application employs a target laser beam to irradiate a target area of ​​a microcrystalline glass substrate immersed in an alkaline solution. After irradiation, a through-hole penetrating the thickness of the microcrystalline glass substrate is formed in the target area. Through this process, when the target laser beam penetrates the alkaline solution and irradiates the surface of the microcrystalline glass substrate, the temperature of the target area and the alkaline solution increases, accelerating the dissolution of the target area and the alkaline solution, and causing etching of the microcrystalline glass substrate. This rapidly forms the through-hole, significantly improving the processing efficiency of the through-hole. Simultaneously, the microcrystalline glass substrate... In areas of the glass substrate other than the target area, especially those far from the vias, the alkaline solution remains at a lower temperature because it is not irradiated by the target laser beam. This means that if the glass-ceramic substrate is immersed in a room-temperature alkaline solution, the target area will reach a locally high temperature upon laser irradiation, forming vias and minimizing the impact on other areas. This significantly improves the smoothness of the via walls, meeting the high requirements of advanced packaging, and also significantly increases the processing efficiency of forming vias in the glass-ceramic substrate. This achieves both high precision and high efficiency in processing vias on the glass-ceramic substrate. Using the above-described laser processing method for glass-ceramics, vias with diameters of 50μm-70μm can be formed on glass-ceramic substrates with a thickness of 500μm-1100μm, with a waist-to-diameter ratio greater than or equal to 80%. The finished glass-ceramic products produced using this laser processing method meet the requirements of advanced packaging.

[0071] To address the aforementioned issues, this application also provides a microcrystalline glass, which is prepared by the laser processing method described below.

[0072] refer to Figure 4 Laser processing methods for microcrystalline glass include: Step S001: Immerse the microcrystalline glass substrate in an alkaline solution, adjusting the liquid level until the difference between the liquid level and the height of the upper surface of the microcrystalline glass substrate is greater than or equal to a preset distance. This step S001 is a pretreatment step. That is, before processing the glass through-holes on the microcrystalline glass substrate, it needs to be pretreated by immersing it in an alkaline solution. Specifically, after immersing the microcrystalline glass substrate in the alkaline solution, the liquid level of the alkaline solution must be higher than the upper surface of the microcrystalline glass substrate to ensure that the microcrystalline glass substrate is completely immersed in the alkaline solution.

[0073] Meanwhile, after immersing the microcrystalline glass substrate in the alkaline solution, it is also necessary to adjust the liquid level of the alkaline solution until the difference between the liquid level and the height of the upper surface of the microcrystalline glass substrate is greater than or equal to a preset distance.

[0074] The alkaline solution in the embodiments of this application is saturated sodium hydroxide.

[0075] The aforementioned saturated sodium hydroxide refers to an alkaline solution with a sodium hydroxide mass fraction of 50%-55% and a sodium hydroxide molar concentration of 26.0-27.0 mol / L. The temperature of the alkaline solution is room temperature.

[0076] Through numerous experiments, it was found that besides the alkaline solution itself needing to meet the aforementioned parameters, the liquid level of the alkaline solution is also a crucial parameter. Specifically, the difference between the liquid level of the alkaline solution and the height of the upper surface of the microcrystalline glass substrate must be greater than or equal to a preset distance. This preset distance directly affects the transmission of the target laser beam. This preset distance is not arbitrarily chosen but requires a comprehensive trade-off between laser transmission efficiency and processing stability. This preset distance represents the "golden range" for generating stable, high-energy laser beams.

[0077] The difference between the liquid level of the alkaline solution and the height of the upper surface of the microcrystalline glass substrate is greater than or equal to a preset distance. After multiple experiments, it was found that this preset distance is 10mm-50mm. When the difference between the liquid level of the alkaline solution and the height of the upper surface of the microcrystalline glass substrate is greater than or equal to the preset distance, and this preset distance meets the requirement of 10mm-50mm, the alkaline solution level in the target area (i.e., the modified area) reaches the preset value, and the diameter of the target laser beam also meets the requirements.

[0078] Following step S001, step S002 is also included: using a target laser beam to irradiate the target area of ​​the microcrystalline glass substrate immersed in an alkaline solution.

[0079] In this embodiment, the target laser beam is a femtosecond Bessel beam with a center wavelength of 515 nm or 1030 nm, a pulse width of 10 fs to 1000 fs, and a cone lens bottom angle of 0.5° to 10°. The duration of irradiation of the microcrystalline glass substrate by the target laser beam is 10 to 15 hours, the temperature of the alkaline solution is room temperature, and the temperature of the modified region is 100°C to 130°C.

[0080] Following step S002, step S003 is also included: after being irradiated by the target laser beam, a modified region with a high aspect ratio is induced to form at the target area location of the microcrystalline glass substrate.

[0081] Following S003 above, step S004 is also included: the modified region is selectively etched away in an alkaline solution to form a glass via penetrating the microcrystalline glass substrate.

[0082] After steps S001-S004, when the target laser beam irradiates the surface of the glass-ceramic through the alkaline solution, the solvent in the alkaline solution only reacts chemically with the glass at the localized high-temperature location, i.e., the target area. This efficiently destroys the structure of the glass-ceramic, forming glass vias that penetrate the glass-ceramic substrate. The overall thickness of the glass-ceramic substrate remains unchanged, and the diameter of the glass via depends on the diameter of the target laser beam, resulting in a very small taper of the via wall. Simultaneously, the subtractive material mechanism is chemical etching, which does not introduce additional stress. Chemical etching also results in excellent wall roughness for the glass vias. Using the above-described laser processing method for glass-ceramics, it is possible to form glass vias with diameters of 50μm-70μm on glass-ceramic substrates with a thickness of 500μm-1100μm. The waist-to-diameter ratio of the glass vias is greater than or equal to 80%, and the resulting glass-ceramic product meets advanced packaging requirements.

[0083] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A laser processing method for microcrystalline glass, characterized in that, Includes the following steps: A target laser beam is used to irradiate the target area of ​​a microcrystalline glass substrate immersed in an alkaline solution; After being irradiated by the target laser beam, a glass through-hole penetrating the thickness direction is formed in the target area of ​​the microcrystalline glass substrate.

2. The laser processing method for microcrystalline glass according to claim 1, characterized in that, Before irradiating the target area of ​​the microcrystalline glass substrate immersed in the alkaline solution with the target laser beam, the method further includes: The microcrystalline glass substrate is immersed in an alkaline solution, and the liquid level of the alkaline solution is adjusted until the difference between the liquid level and the height of the upper surface of the microcrystalline glass substrate is greater than or equal to a preset distance.

3. The laser processing method for microcrystalline glass according to claim 1, characterized in that, The target laser beam is a Gaussian laser beam, a femtosecond Bessel laser beam, or a flat-top laser beam.

4. The laser processing method for microcrystalline glass according to claim 1, characterized in that, The target laser beam is a femtosecond Bessel beam; the formation of a through-hole penetrating the thickness direction in the target region of the microcrystalline glass substrate after irradiation by the target laser beam includes: After being irradiated by the target laser beam, a modified region with a high aspect ratio is induced to form at the target region location on the microcrystalline glass substrate; The modified region is selectively etched away in the alkaline solution to form the glass via that penetrates the microcrystalline glass substrate.

5. The laser processing method for microcrystalline glass according to claim 4, characterized in that, The center wavelength of the femtosecond Bessel beam is 515nm or 1030nm, the pulse width is 10fs-1000fs, and the bottom angle of the conical lens is 0.5°-10°.

6. The laser processing method for microcrystalline glass according to claim 4, characterized in that, The target laser beam irradiates the microcrystalline glass substrate for 10-15 hours, the alkaline solution is at room temperature, and the modified region is at 100℃-130℃.

7. The laser processing method for microcrystalline glass according to any one of claims 1-6, characterized in that, The alkaline solution is a sodium hydroxide or potassium hydroxide solution, and the alkaline solution is saturated at room temperature.

8. The laser processing method for microcrystalline glass according to any one of claims 1-6, characterized in that, The diameter of the glass through-hole is 50μm-70μm; And / or, the waist-to-diameter ratio of the glass through-hole is greater than or equal to 80%.

9. The laser processing method for microcrystalline glass according to any one of claims 1-6, characterized in that, The thickness of the microcrystalline glass substrate ranges from 100μm to 1100μm.

10. A microcrystalline glass, characterized in that, The microcrystalline glass is obtained by the laser processing method of the microcrystalline glass as described in any one of claims 1-9.

Images