Glass substrate grooving process for embedded packaging

Abstract

The application belongs to the field of advanced semiconductor packaging technology, and particularly relates to a glass substrate slotting process for embedded packaging. The glass substrate slotting process for embedded packaging comprises the following steps: step S1, a guide notch is made in an exposed glass substrate target processing area as a starting point for subsequent slot hole processing; step S2, laser-induced slot holes are directionally expanded along the guide notch: a pulsed laser beam is used to perform scanning irradiation along the guide structure, and the slot holes to be processed and shaped are directionally expanded from the guide notch, and then the slot holes are processed and formed; and step S3, electronic components are embedded in the finally formed slot holes. The application can improve the processing quality and efficiency, and can be suitable for manufacturing glass substrate microstructures of high-density and high-performance embedded packaging devices.

Description

Technical Field

[0001] This invention relates to the field of advanced semiconductor packaging technology, and more specifically to a glass substrate slotting process for embedded packaging. Background Technology

[0002] As integrated circuits evolve towards higher density and higher performance, embedded packaging technology using glass as the core substrate material has attracted much attention due to glass's excellent dimensional stability, low radio frequency loss, and high insulation. Fabricating microgrooves and interconnect vias in the glass substrate for embedding passive components (such as capacitors, inductors, and resistors) or small-sized chips is a key step in realizing this technology.

[0003] The mainstream glass micromachining technologies currently include: (1) Wet / dry etching combined with pattern transfer process: This process forms a patterned mask by coating, exposure, and development, and then performs chemical etching. The advantage is that the sidewalls are smooth and the precision is high, but it is difficult to process structures with a large depth-to-width ratio. The etching rate and shape control are difficult. The isotropic characteristics of wet etching make it difficult to control the perpendicularity of the sidewalls. Although dry etching can achieve a near-vertical hole wall morphology, it is limited by the low etching rate and high equipment cost. (2) Laser direct ablation process: High-energy laser pulses are used to directly remove glass materials. This process is flexible and does not require a mask, but the heat-affected zone will cause microcracks, slag and rough sidewalls in the processing area, which seriously affects the electrical performance and long-term reliability of the interconnect. (3) Laser and etching composite process: First, a rough groove is opened with a laser, and then it is trimmed by etching. Although this method can improve the sidewall quality, the deep microcracks introduced by the laser step will still expand in the subsequent etching.

[0004] It is evident that the aforementioned methods in the existing technologies exhibit their own characteristics in different application scenarios, but also have obvious limitations. In other words, the existing technologies all face the dilemma of not being able to simultaneously achieve "high quality (no cracks, high perpendicularity)," "high efficiency (fast processing speed)," and "high aspect ratio," especially in scenarios where it is necessary to embed components with extremely high requirements for sidewall quality and interface integrity, where the limitations of the existing technologies are even more pronounced. Summary of the Invention

[0005] The present invention aims to overcome the shortcomings of the prior art and provide a glass substrate slotting process for embedded packaging, which can improve processing quality and processing efficiency, and is applicable to the manufacture of glass substrate microstructures for high-density, high-performance embedded packaging devices.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A glass substrate slotting process for embedded packaging, characterized by comprising the following steps: Step S1. Create a guide notch in the target processing area of ​​the exposed glass substrate as the starting point for subsequent slot processing; Step S2. Laser-induced slot hole directional expansion along the guide notch: A pulsed laser beam is used to scan and irradiate along the guide structure to induce the slot hole to be formed to expand directionally from the guide notch, thereby forming the slot hole; Step S3. Embed electronic components in the final formed slot.

[0007] Furthermore, the guide notch in S1 is fabricated by wet or dry chemical etching or by scanning with a laser beam.

[0008] When the method for fabricating the guide notch in S1 is chemical etching, the glass substrate slotting process for embedded packaging of the present invention further includes step S0, which is before S1. Step S0 is pattern mask preparation: a photosensitive material is coated on a clean and dried glass substrate, and a pattern mask is formed by photolithography exposure and development to expose the target area to be processed.

[0009] Because the etching process creates tiny V-shaped or U-shaped grooves with pointed bottoms (i.e., guide notches), these guide notches are equivalent to pre-introducing a controllable, continuous stress concentration line and a larger specific surface area into the complete glass lattice structure. This notch not only defines the processing path but, more importantly, significantly reduces the material bonding energy that subsequent laser processing needs to overcome. Specifically, in the glass substrate grooving process of this invention, after etching, the pulsed laser beam is focused into a focal line that illuminates the guide notch on the glass substrate, causing the focal line to process and form a groove along the guide notch. It is evident that the laser in S2 no longer needs to "chise" from a complete plane but rather expands from an existing "crack" (i.e., guide notch), much like splitting firewood; once a crack appears, it is easy to split the firewood along the crack. Therefore, this invention avoids cracks caused by laser spin cutting and significantly reduces the requirements for laser peak power and energy, allowing the use of more economical lasers with higher repetition rates; simultaneously, the chemical pre-etching process requires less material and takes less time, resulting in lower overall costs. Moreover, the resulting slot sidewalls have almost no heat-affected zone and no laser-induced microcracks, resulting in higher quality and better performance. The slot sidewall roughness obtained by the glass substrate slotting process of this invention is in the submicron level (Ra<100nm).

[0010] Preferably, the depth of the guide notch is 0.1-2 micrometers.

[0011] Preferably, the etching time is controlled to make the bottom radius of curvature of the guide notch less than 2 micrometers to form a sharp stress concentration point.

[0012] Preferably, the etching solution is a hydrofluoric acid-based etching solution. More preferably, the hydrofluoric acid-based etching solution is an aqueous solution of hydrofluoric acid or a buffered oxide etchant, and the concentration of hydrofluoric acid in the hydrofluoric acid-based etching solution ranges from 0.5 wt% to 10 wt%.

[0013] Preferably, the etching solution is a mixture of hydrofluoric acid, ammonium fluoride and water, wherein ammonium fluoride acts as a buffer to stabilize the HF concentration during the etching process, making the etching rate more constant and predictable; at the same time, it can also reduce insoluble matter: ammonium fluoride can form a soluble complex with the fluorosilicic acid generated in the reaction, which greatly reduces the adhesion of white precipitates (fluorosilicates) and obtains a cleaner surface.

[0014] Furthermore, the etching time can typically be controlled between 10 seconds and 90 minutes to obtain a guide notch of suitable size. The etching temperature can be 25°C-50°C, preferably 25°C-40°C. Generally, the higher the temperature, the faster the etching speed. The etching temperature and time can be set as needed.

[0015] Furthermore, in step S2, the wavelength range of the pulsed laser is from ultraviolet to near infrared, and the pulse width is on the order of nanoseconds, picoseconds, or femtoseconds; the diameter of the focused spot of the laser is less than or equal to the opening width of the guide notch, and the focal plane is set at the bottom of the guide notch or slightly below the bottom during scanning.

[0016] Furthermore, in step S2, when the laser scans in continuous or pulse train mode, the continuity and depth of the slot expansion along the guide notch can be controlled by adjusting the scanning speed and pulse repetition frequency.

[0017] Furthermore, in step S2, before or during laser scanning, auxiliary stress may be applied to the guide notch or a local area of ​​the glass substrate. The auxiliary stress may include mechanical stress, thermal stress, or surface tension generated by applying a specific atmosphere.

[0018] Furthermore, if necessary, step S21 can be added after step S2. The specific operation of S21 is as follows: further process (fine-tuning) the prototype of the slot to obtain the final microstructure (slot) with preset size and smooth sidewalls.

[0019] Furthermore, the final formed slot has a sidewall roughness Ra of less than 0.1 micrometers, and its cross-sectional shape is one of vertical wall, positive cone, or inverted trapezoid.

[0020] Furthermore, the resulting slots include microgrooves, cavities, and interconnect vias for embedding passive components or small-sized chips.

[0021] The present invention also discloses an embedded glass-based encapsulation substrate prepared by any of the above methods.

[0022] Specifically, this technology has the following positive effects compared with existing technologies: (1) Compared with the prior art, the S1 step of the present invention rapidly forms a guide notch, so that the subsequent laser only requires extremely low energy (usually only 1 / 10 to 1 / 5 of the energy required for direct ablation to penetrate) to drive crack propagation. It can be seen that the present invention can significantly reduce energy consumption and processing costs, greatly reduce the requirements for laser peak power and energy, and can use more economical lasers with higher repetition rates; the chemical pre-etching requires less material and takes less time, resulting in low overall cost.

[0023] (2) Compared with the prior art, the processing quality of the present invention is superior: the material removal of the target processing area of ​​the glass substrate is mainly completed by brittle fracture rather than melting and vaporization. The processed slot sidewalls are smooth and almost free of heat-affected zones, recast layers and laser-induced microcracks. The sidewall roughness is submicron level (Ra<100nm). At the same time, since the expansion of the processed slot is strongly guided by the geometry of the guide notch and the scanning path, the lateral diffusion is minimal. It can achieve high-quality deep holes / grooves with a sidewall perpendicularity close to 1:1 and a depth-to-width ratio greater than 10:1. The pattern fidelity is extremely high. It can be seen that the slots processed by the present invention have higher quality and superior performance.

[0024] (3) This invention combines chemical etching with laser grooving process. It achieves precise processing by forming a guide notch through chemical etching and then expanding the laser grooving mechanism. It breaks away from the traditional thinking framework of "removal" or "ablation". The mechanism is unique and cleverly integrates chemical etching, fracture mechanics and laser processing. It can greatly improve processing efficiency and quality and reduce production costs. Detailed Implementation

[0025] The following embodiments are provided to better understand the present invention, but are not intended to limit the invention. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods. Example 1

[0026] This embodiment demonstrates the processing of a blind or through hole with a diameter of 50 μm on a glass substrate with a thickness of 510 μm (the hole depth can be ≤510 μm, such as a through hole with a depth of 510 μm, or a blind hole with a depth of 500 μm, or a blind hole with a depth of 480 μm, or a blind hole with a depth of 450 μm, etc.).

[0027] This embodiment provides a glass substrate slotting process for embedded packaging, which includes the following steps: Step S0: Patterned mask preparation: A photosensitive material is coated on a clean and dried glass substrate, and a patterned mask is formed by photolithography exposure and development to expose the target area to be processed; Step S1. A guide notch is created in the target processing area of ​​the exposed glass substrate using a wet chemical etching method to serve as the starting point for subsequent slot processing; Step S2. Laser-induced slot hole directional expansion along the guide notch: A pulsed laser beam is used to scan and irradiate along the guide structure to induce the slot hole to be formed to expand directionally from the guide notch, thereby forming the slot hole; Step S3. Embed electronic components in the final formed slot.

[0028] In S1 of this embodiment, the etching solution is an aqueous solution of hydrofluoric acid with a concentration of 2wt%, the etching temperature is 30℃±1℃, the etching time is 2 minutes, and the resulting guide notch is a pit with a maximum depth of about 1.9μm.

[0029] In S2 of this embodiment, a nanosecond pulsed ultraviolet laser (wavelength 355 nm, pulse width 30 ns, repetition frequency 30 kHz) is used. This wavelength was chosen because it has a high absorption rate on the rough, freshly etched surface formed after pre-cracking. The laser focus is precisely aligned with the deepest point of the circular pit, and a spiral inward scan is performed with this point as the center, with a pitch of 3 μm and a scanning speed of 1 mm / s. The laser is focused to a spot diameter of approximately 20 μm, and the single-pulse energy can be set to 10-30 μJ, which is much lower than the energy required to directly drill a hole in the glass (typically >80 μJ). When the laser irradiates the bottom of the notch, a bright flash and slight gas ejection can be observed. A crisp micro-crackling sound is accompanied by the processing. Taking the formation of a 480 μm blind hole as an example, the total processing time is less than 1 second. Result: After processing, a deep hole with a depth of approximately 480 μm is formed. Optical microscopy shows that the hole entrance diameter is approximately 50.1 μm, and the hole shape is round. Example 2

[0030] This embodiment demonstrates the processing of a blind or through hole with a diameter of 50 μm on a glass substrate with a thickness of 510 μm (the hole depth can be ≤510 μm, such as a through hole with a depth of 510 μm, or a blind hole with a depth of 500 μm, or a blind hole with a depth of 480 μm, or a blind hole with a depth of 450 μm, etc.).

[0031] This embodiment provides a glass substrate slotting process for embedded packaging, which includes the following steps: Step S0: Patterned mask preparation: A photosensitive material is coated on a clean and dried glass substrate, and a patterned mask is formed by photolithography exposure and development to expose the target area to be processed; Step S1. A guide notch is created in the target processing area of ​​the exposed glass substrate using a wet chemical etching method to serve as the starting point for subsequent slot processing; Step S2. Laser-induced slot hole directional expansion along the guide notch: A pulsed laser beam is used to scan and irradiate along the guide structure to induce the slot hole to be formed to expand directionally from the guide notch, thereby forming the slot hole; Step S3. Embed electronic components in the final formed slot.

[0032] In S1 of this embodiment, the etching solution is an aqueous solution of hydrofluoric acid with a concentration of 5 wt%, the etching temperature is 30℃±1℃, the etching time is 20 seconds, and the resulting guide notch is a pit with a maximum depth of about 1.1 μm.

[0033] In S2 of this embodiment, a nanosecond pulsed ultraviolet laser (wavelength 355 nm, pulse width 30 ns, repetition frequency 30 kHz) is used. This wavelength was chosen because it has a high absorption rate on the rough, freshly etched surface formed after pre-cracking. The laser focus is precisely aligned with the deepest point of the circular pit, and a spiral inward scan is performed with this point as the center, with a pitch of 3 μm and a scanning speed of 1 mm / s. The laser is focused to a spot diameter of approximately 20 μm, and the single-pulse energy can be set to 10-30 μJ, which is much lower than the energy required to directly drill a hole in the glass (typically >80 μJ). When the laser irradiates the bottom of the notch, a bright flash and slight gas ejection can be observed. A crisp micro-crackling sound is accompanied by the processing. Taking the formation of a 480 μm blind hole as an example, the total processing time is less than 1 second. Result: After processing, a deep hole with a depth of approximately 480 μm is formed. Optical microscopy shows that the hole inlet diameter is approximately 50.2 μm, and the hole shape is round. Example 3

[0034] This embodiment demonstrates the processing of a blind or through hole with a diameter of 50 μm on a glass substrate with a thickness of 510 μm (the hole depth can be ≤510 μm, such as a through hole with a depth of 510 μm, or a blind hole with a depth of 500 μm, or a blind hole with a depth of 480 μm, or a blind hole with a depth of 450 μm, etc.).

[0035] This embodiment provides a glass substrate slotting process for embedded packaging, which includes the following steps: Step S0: Patterned mask preparation: A photosensitive material is coated on a clean and dried glass substrate, and a patterned mask is formed by photolithography exposure and development to expose the target area to be processed; Step S1. A guide notch is created in the target processing area of ​​the exposed glass substrate using a wet chemical etching method to serve as the starting point for subsequent slot processing; Step S2. Laser-induced slot hole directional expansion along the guide notch: A pulsed laser beam is used to scan and irradiate along the guide structure to induce the slot hole to be formed to expand directionally from the guide notch, thereby forming the slot hole; Step S3. Embed electronic components in the final formed slot.

[0036] In S1 of this embodiment, the etching solution is a mixture of hydrofluoric acid, ammonium fluoride, and water. The etching solution is prepared as follows: a 40% (w / w) ammonium fluoride aqueous solution and a 49% (w / w) hydrofluoric acid aqueous solution are mixed at a volume ratio of 6:1. The mixture is then diluted 3 times with deionized water to obtain the etching solution. In the etching solution, ammonium fluoride acts as a buffer, stabilizing the HF concentration during the etching process, making the etching rate more constant and predictable. It also reduces insoluble matter: ammonium fluoride can form a soluble complex with the fluorosilicic acid generated in the reaction, greatly reducing the adhesion of white precipitates (fluorosilicates) and obtaining a cleaner surface. In this embodiment, the etching temperature is 30℃±1℃, the etching time is 10 minutes, and the resulting guide notch is a pit with a maximum depth of approximately 1.4 μm.

[0037] In S2 of this embodiment, a nanosecond pulsed ultraviolet laser (wavelength 355 nm, pulse width 30 ns, repetition frequency 30 kHz) is used. This wavelength was chosen because it has a high absorption rate on the rough, freshly etched surface formed after pre-cracking. The laser focus is precisely aligned with the deepest point of the circular pit, and a spiral inward scan is performed with this point as the center, with a pitch of 3 μm and a scanning speed of 1 mm / s. The laser is focused to a spot diameter of approximately 20 μm, and the single-pulse energy can be set to 10-30 μJ, which is much lower than the energy required to directly drill a hole in the glass (typically >80 μJ). When the laser irradiates the bottom of the notch, a bright flash and slight gas ejection can be observed. A crisp micro-crackling sound is accompanied by the processing. Taking the formation of a 480 μm blind hole as an example, the total processing time is less than 1 second. Result: After processing, a deep hole with a depth of approximately 480 μm is formed. Optical microscopy shows that the hole entrance diameter is approximately 50.1 μm, and the hole shape is round. Example 4

[0038] This embodiment demonstrates the processing of a blind or through hole with a diameter of 50 μm on a glass substrate with a thickness of 510 μm (the hole depth can be ≤510 μm, such as a through hole with a depth of 510 μm, or a blind hole with a depth of 500 μm, or a blind hole with a depth of 480 μm, or a blind hole with a depth of 450 μm, etc.).

[0039] This embodiment provides a glass substrate slotting process for embedded packaging, which includes the following steps: Step S0: Patterned mask preparation: A photosensitive material is coated on a clean and dried glass substrate, and a patterned mask is formed by photolithography exposure and development to expose the target area to be processed; Step S1. A guide notch is created in the target processing area of ​​the exposed glass substrate using a wet chemical etching method to serve as the starting point for subsequent slot processing; Step S2. Laser-induced slot hole directional expansion along the guide notch: A pulsed laser beam is used to scan and irradiate along the guide structure to induce the slot hole to be formed to expand directionally from the guide notch, thereby forming the slot hole; Step S3. Embed electronic components in the final formed slot.

[0040] In S1 of this embodiment, the etching solution is a mixture of hydrofluoric acid, ammonium fluoride, and water. The etching solution is prepared as follows: a 40% (w / w) ammonium fluoride aqueous solution and a 49% (w / w) hydrofluoric acid aqueous solution are mixed at a volume ratio of 10:1. The mixture is then diluted three times with deionized water to obtain the etching solution. In the etching solution, ammonium fluoride acts as a buffer, stabilizing the HF concentration during the etching process, making the etching rate more constant and predictable. It also reduces insoluble matter: ammonium fluoride can form a soluble complex with the fluorosilicic acid generated in the reaction, greatly reducing the adhesion of white precipitates (fluorosilicates) and obtaining a cleaner surface. In this embodiment, the etching temperature is 30℃±1℃, the etching time is 15 minutes, and the resulting guide notch is a pit with a maximum depth of approximately 1.3 μm.

[0041] In S2 of this embodiment, a nanosecond pulsed ultraviolet laser (wavelength 355 nm, pulse width 30 ns, repetition frequency 30 kHz) is used. This wavelength was chosen because it has a high absorption rate on the rough, freshly etched surface formed after pre-cracking. The laser focus is precisely aligned with the deepest point of the circular pit, and a spiral inward scan is performed with this point as the center, with a pitch of 3 μm and a scanning speed of 1 mm / s. The laser is focused to a spot diameter of approximately 20 μm, and the single-pulse energy can be set to 10-30 μJ, which is much lower than the energy required to directly drill a hole in the glass (typically >80 μJ). When the laser irradiates the bottom of the notch, a bright flash and slight gas ejection can be observed. A crisp micro-crackling sound is accompanied by the processing. Taking the formation of a 480 μm blind hole as an example, the total processing time is less than 1 second. Result: After processing, a deep hole with a depth of approximately 480 μm is formed. Optical microscopy shows that the hole entrance diameter is approximately 50.1 μm, and the hole shape is round. Example 5

[0042] This embodiment demonstrates the processing of a blind or through hole with a diameter of 50 μm on a glass substrate with a thickness of 510 μm (the hole depth can be ≤510 μm, such as a through hole with a depth of 510 μm, or a blind hole with a depth of 500 μm, or a blind hole with a depth of 480 μm, or a blind hole with a depth of 450 μm, etc.).

[0043] This embodiment provides a glass substrate slotting process for embedded packaging, which includes the following steps: Step S0: Patterned mask preparation: A photosensitive material is coated on a clean and dried glass substrate, and a patterned mask is formed by photolithography exposure and development to expose the target area to be processed; Step S1. A guide notch is created in the target processing area of ​​the exposed glass substrate using a wet chemical etching method to serve as the starting point for subsequent slot processing; Step S2. Laser-induced slot hole directional expansion along the guide notch: A pulsed laser beam is used to scan and irradiate along the guide structure to induce the slot hole to be formed to expand directionally from the guide notch, thereby forming the slot hole; Step S3. Embed electronic components in the final formed slot.

[0044] In S1 of this embodiment, the etching solution is a mixture of hydrofluoric acid, ammonium fluoride, and water. The etching solution is prepared as follows: a 40% (w / w) ammonium fluoride aqueous solution and a 49% (w / w) hydrofluoric acid aqueous solution are mixed at a volume ratio of 10:1. The mixture is then diluted 5 times with deionized water to obtain the etching solution. In the etching solution, ammonium fluoride acts as a buffer, stabilizing the HF concentration during the etching process, making the etching rate more constant and predictable. It also reduces insoluble matter: ammonium fluoride can form a soluble complex with the fluorosilicic acid generated in the reaction, greatly reducing the adhesion of white precipitates (fluorosilicates) and obtaining a cleaner surface. In this embodiment, the etching temperature is 30℃±1℃, the etching time is 18 minutes, and the resulting guide notch is a pit with a maximum depth of approximately 1.0 μm.

[0045] In S2 of this embodiment, a nanosecond pulsed ultraviolet laser (wavelength 355 nm, pulse width 30 ns, repetition frequency 30 kHz) is used. This wavelength was chosen because it has a high absorption rate on the rough, freshly etched surface formed after pre-cracking. The laser focus is precisely aligned with the deepest point of the circular pit, and a spiral inward scan is performed with this point as the center, with a pitch of 3 μm and a scanning speed of 1 mm / s. The laser is focused to a spot diameter of approximately 20 μm, and the single-pulse energy can be set to 10-30 μJ, which is much lower than the energy required to directly drill a hole in the glass (typically >80 μJ). When the laser irradiates the bottom of the notch, a bright flash and slight gas ejection can be observed. A crisp micro-crackling sound is accompanied by the processing. Taking the formation of a 480 μm blind hole as an example, the total processing time is less than 1 second. Result: After processing, a deep hole with a depth of approximately 480 μm is formed. Optical microscopy shows that the hole entrance diameter is approximately 50.1 μm, and the hole shape is round. Comparative Example

[0046] This embodiment also uses the example of processing a blind or through hole with a diameter of 50 μm on a glass substrate with a thickness of 510 μm (the hole depth can be ≤510 μm, such as a through hole with a depth of 510 μm, or a blind hole with a depth of 500 μm, or a blind hole with a depth of 480 μm, or a blind hole with a depth of 450 μm, etc.). This embodiment adopts the conventional laser direct ablation process (i.e., using high-energy laser pulses to directly remove glass material), and the specific steps are as follows: The glass substrate is cleaned and dried, then fixed on a laser processing platform. Laser destruction of the precursor glass is performed using laser conditions of 532nm wavelength, 15 pulses / pulse trains, 100kHz reproducibility, and an energy range of 60μJ to 190μJ. (The 532nm wavelength (green light) was chosen because it has moderate absorption for glass and is the mainstream choice in industry. Furthermore, the single-pulse energy can be adjusted according to the glass thickness and aperture; typically, a higher energy density is required to ensure penetration.) The scanning method is a spiral filling scan. After processing, the substrate is cleaned to remove debris from the aperture, and parameters such as aperture diameter, taper, edge chipping, and aperture wall quality are inspected.

[0047] The processing results of Examples 1 to 5 and the comparative examples are shown in Table 1 below.

[0048] Table 1

[0049] As can be seen from the table above (Table 1), the slots processed by the present invention have higher quality and better performance, and can be applied to a wider range of applications.

[0050] Meanwhile, this invention can significantly reduce energy consumption and processing costs, greatly reducing the requirements for laser peak power and energy, and allowing the use of more economical lasers with higher repetition rates. The chemical pre-etching process (step S1) of this invention uses less material and takes less time, resulting in lower overall costs. For example, the specific comparison results for processing a 50μm diameter through-hole on a 500μm thick borosilicate glass are shown in Table 2. Table 2

[0051] In addition, compared with etching process, the present invention has high processing efficiency. The etching time of step S1 of the present invention is usually between several seconds and several minutes, and the processing time of S2 is generally less than 1 second. The total processing time is much less than the etching processing time.

[0052] It should be noted that the parameters in Examples 1-5 above are for demonstration purposes only. During the production process, the etching solution, etching temperature, and etching time can be adjusted according to the actual situation. For example, in actual processing, the etching time can be controlled according to the target. Generally, the etching time can be controlled between 10 seconds and 90 minutes to obtain a guide notch of a suitable size, such as a guide notch with a depth of 2%-30% of the target depth. The etching temperature can be 25℃-50℃, preferably 25℃-40℃. Generally, the higher the temperature, the faster the etching speed. The etching temperature and time can be set as needed.

[0053] In some other application scenarios, in addition to the wet etching methods of Examples 1-5, dry etching can also be used, such as using RIE dry etching (CF4 gas) to form guide notches, and then laser-induced grooves to expand directionally along the guide notches.

[0054] In some other applications, in addition to etching to form guide notches, femtosecond lasers (low energy) can be used to pre-scan and form modification trajectories, and then nanosecond lasers (slightly higher energy) can be used to induce cracks to propagate along the trajectories.

[0055] In some other application scenarios, S21 can be added after step S2 as needed. The specific operation of S21 is as follows: further process (fine-tuning) the slot prototype to obtain the final microstructure (slot) with preset size and smooth sidewalls.

[0056] The glass substrate thicknesses in Examples 1-5 and the comparative examples above are for illustrative purposes only and are not limitations. In application, the thickness of the glass substrate to be processed can typically be in the range of 20 μm to approximately 3000 μm, and the material of the glass substrate can be borosilicate glass, quartz glass, alkali-free glass, soda-lime glass, etc.

[0057] The above description is merely an embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention shall still fall within the protection scope of the technical solution of the present invention.

Claims

1. A glass substrate slotting process for embedded packaging, characterized in that, Includes the following steps: Step S1. Create a guide notch in the target processing area of ​​the exposed glass substrate as the starting point for subsequent slot processing; Step S2. Laser-induced slot hole directional expansion along the guide notch: A pulsed laser beam is used to scan and irradiate along the guide structure to induce the slot hole to be formed to expand directionally from the guide notch, thereby forming the slot hole; Step S3. Embed electronic components in the final formed slot.

2. The glass substrate slotting process for embedded packaging according to claim 1, characterized in that, When the method for fabricating the guide notch in S1 is chemical etching, the glass substrate slotting process for embedded packaging of the present invention further includes step S0, which is before S1. Step S0 is pattern mask preparation: a photosensitive material is coated on a clean and dried glass substrate, and a pattern mask is formed by photolithography exposure and development to expose the target area to be processed.

3. The glass substrate slotting process for embedded packaging according to claim 2, characterized in that, The depth of the guide notch is 0.1-2 micrometers.

4. The glass substrate slotting process for embedded packaging according to claim 2, characterized in that, The etching time is controlled to make the bottom radius of curvature of the guide notch less than 2 micrometers.

5. The glass substrate slotting process for embedded packaging according to claim 2, characterized in that, The etching solution is a hydrofluoric acid-based etching solution, and the concentration of hydrofluoric acid in the hydrofluoric acid-based etching solution ranges from 0.5wt% to 10wt%.

6. The glass substrate slotting process for embedded packaging according to claim 5, characterized in that, The etching solution is a mixture of hydrofluoric acid, ammonium fluoride and water.

7. The glass substrate slotting process for embedded packaging according to claim 1, characterized in that, In step S2, the wavelength range of the pulsed laser is from ultraviolet to near infrared, and the pulse width is on the order of nanoseconds, picoseconds, or femtoseconds; the diameter of the focused spot of the laser is less than or equal to the opening width of the guide notch, and the focal plane is set at the bottom of the guide notch or slightly below the bottom during scanning.

8. The glass substrate slotting process for embedded packaging according to claim 1, characterized in that, In step S2, before or during laser scanning, auxiliary stress may be applied to the guide notch or a local area of ​​the glass substrate. The auxiliary stress may include mechanical stress, thermal stress, or surface tension generated by applying a specific atmosphere.

9. The glass substrate slotting process for embedded packaging according to claim 1, characterized in that, Step S21 is added after step S2. The specific operation of S21 is as follows: the slot prototype is further processed to obtain the final microstructure with preset size and smooth sidewalls.

10. The glass substrate slotting process for embedded packaging according to claim 1, characterized in that, The resulting slots include microgrooves, cavities, and interconnect vias for embedding passive components or small-sized chips.

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