Environment-friendly strong base liquid medicine processing method for TGV glass via hole wet etching

Abstract

The application discloses an environment-friendly strong-alkali chemical solution TGV glass via-hole wet etching processing method and a prepared substrate, and belongs to the technical field of glass processing. The method comprises the following steps: substrate pretreatment, laser modification, environment-friendly strong-alkali wet etching, neutralization cleaning and drying, via-hole detection and the like. In addition, the qualified substrate can be subjected to plasma activation, metal seed layer deposition and electroplating hole filling treatment. The application adopts a fluorine-free environment-friendly strong-alkali etching solution, combines with ultrafast femtosecond laser modification and two-stage step-by-step etching process, can realize a minimum 5 mu m forming aperture, a depth-width ratio of more than 20:1, effectively reduces silicon scale deposition and hole wall defects. The prepared substrate is suitable for three-dimensional advanced packaging integrated process and the like, has the advantages of good environmental protection, high processing precision and strong practicability, solves the problems of traditional fluorine-containing etching solution environmental pollution and poor via-hole processing quality and the like, and can realize large-scale mass production.

Description

Technical Field

[0001] This invention relates to the field of glass processing technology, specifically to an environmentally friendly strong alkaline TGV glass through-hole wet etching process. Background Technology

[0002] With the development of electronic information technology, technologies such as 3D advanced packaging and optoelectronic co-packaging are constantly increasing the requirements for the integration and electrical performance of packaging carriers. Glass materials have become ideal packaging carriers due to their advantages such as low dielectric constant, excellent insulation, and high matching degree with the thermal expansion coefficient of silicon. As the core of vertical interconnection of glass substrates, the processing quality of TGV technology directly determines the packaging performance.

[0003] TGV processing is mainly divided into dry etching and wet etching. Dry etching has high precision but high equipment cost and low efficiency, and is prone to plasma damage. Wet etching is simple and low cost, making it the first choice for industrial mass production, but it has obvious shortcomings: existing wet etching methods mostly use fluorine-containing etching solutions, which are highly toxic, difficult to treat waste liquid, and pollute the environment; the etching selectivity is poor, making it difficult to achieve small-sized, high aspect ratio through-hole processing, resulting in many hole wall defects; silicon scale is easy to accumulate, affecting the etching solution life and product qualification rate; the connection between laser modification and wet etching is poor, which can easily lead to incomplete forming or over-etching problems. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes an environmentally friendly strong alkaline TGV glass through-hole wet etching method that utilizes a fluorine-free environmentally friendly strong alkaline etching solution system, combined with laser modification pretreatment and segmented etching process, to solve the problems of etching solution pollution, silicon scale deposition, and hole wall defects.

[0005] To solve the above-mentioned technical problems, the technical solution proposed by this invention is: a method for wet etching of TGV glass through holes using an environmentally friendly strong alkaline solution, comprising the following steps: Step 1: Substrate pretreatment: Select a glass substrate suitable for through-hole processing, and process it sequentially with solvent degreasing, multi-stage pure water cleaning, and constant temperature drying to thoroughly remove dust, oil and organic impurities adhering to the substrate surface, ensuring that the surface cleanliness of the substrate meets the requirements of subsequent laser processing. Step 2, Laser Modification Treatment: Ultrafast femtosecond laser is used to irradiate the interior of the glass substrate in a directional manner, and continuous etching is performed along the thickness direction of the substrate to form a through-type modification channel. The modified area can significantly improve the etching rate and provide a preset etching path for subsequent selective wet etching. Step 3, Environmentally friendly strong alkaline wet etching: The laser-modified glass substrate is immersed in a fluorine-free environmentally friendly strong alkaline etching solution system for constant temperature etching. The modified channel is dissolved in a directional manner by relying on the difference in corrosion rate between the modified channel and the ordinary glass body, and finally a complete and through glass hole is formed. The etching solution is continuously circulated, filtered and purified during the etching process. Step 4, Neutralization Cleaning and Drying: After etching, the substrate undergoes acid neutralization, multi-stage pure water ultrasonic cleaning, low-speed draining, and constant temperature drying processes in sequence to completely remove residual alkaline solution from the substrate surface and prevent residual solution from corroding the inner wall of the through hole. Step 5: Inspection of the appearance and dimensions of the through holes: The formed through holes are fully scanned and inspected using high-precision visual inspection equipment. The hole diameter, hole wall roundness, hole position coordinate accuracy, leakage holes and micro-cracks on the inner wall are verified simultaneously, and qualified glass substrates are sorted and screened.

[0006] Furthermore, in step two, a minimum forming aperture of 5μm is achieved by adjusting the laser output parameters, and the depth-to-width ratio of the through hole is controlled to above 20:1 by adjusting the laser processing parameters.

[0007] Furthermore, in step three, the etching temperature is maintained at a constant 80–120°C, and the etching solution is continuously circulated and filtered during the etching process to reduce the deposition of silicon scale on the inner wall of the through-hole and in the etching tank.

[0008] Furthermore, the environmentally friendly strong alkaline etching solution does not contain fluorides, and the system components include strong alkali, complexing stabilizer, penetrating wetting agent, and silicon scale inhibitor. It relies on the synergistic effect of the component ratio to reduce the roughness of the inner wall of the through hole and accurately control the taper of the through hole.

[0009] Furthermore, step three employs a two-stage step etching process. The first stage of etching removes the laser-modified core area, and the second stage of fine-tuning etching repairs the morphology of the inner wall of the through hole. An intermediate water washing and descaling process is set between the two etching stages.

[0010] Furthermore, step five employs a multimodal imaging detection mode to simultaneously acquire multi-dimensional data on the through-hole size, contour, and inner wall defects, thereby achieving integrated detection of the through-hole's full size and defects.

[0011] Furthermore, after the through-hole inspection is completed, the glass substrate undergoes plasma activation and metal seed layer deposition processes in sequence to form a uniformly attached metal substrate on the inner wall of the through-hole.

[0012] Furthermore, after the metal seed layer is deposited, an electroplating filling process is used to fill the through holes with conductive metal, thereby improving the metal layer coverage and interface bonding strength of the through hole sidewalls.

[0013] A TGV glass through-hole substrate prepared by a processing method is suitable for the integration process of three-dimensional advanced packaging, optoelectronic co-packaging, radio frequency passive devices, and microelectromechanical sensor substrates.

[0014] The advantages of this invention compared to the prior art are: It adopts a fluorine-free, environmentally friendly strong alkaline etching solution system, which contains no fluorides. No toxic hydrogen fluoride gas is generated during the etching process. Waste liquid treatment is simple and low-cost, meets environmental protection production requirements, and effectively solves the problems of environmental pollution and harm to human health caused by traditional fluorine-containing etching solutions.

[0015] By using ultrafast femtosecond laser modification to form a preset etching path, combined with a two-stage step-by-step etching process, a minimum forming hole diameter of 5μm can be achieved, with an aspect ratio of more than 20:1 and a hole wall roughness Ra≤0.5μm. It can precisely control the taper of the through hole, reduce defects such as microcracks in the hole wall, and effectively reduce silicon scale deposition, thereby improving the product qualification rate.

[0016] The processing technology is simple and easy to operate, enabling large-scale mass production. The prepared TGV glass through-hole substrate, after metallization treatment, has excellent conductivity and is suitable for high-end integrated processes such as 3D advanced packaging and optoelectronic co-packaging, meeting the development needs of the electronics industry. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the processing method of the present invention. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings.

[0019] Example 1 This embodiment provides an environmentally friendly, strongly alkaline TGV glass through-hole wet etching method suitable for three-dimensional advanced packaging integration processes. The specific steps are as follows: Step 1: Substrate pretreatment: Select a suitable borosilicate glass substrate and sequentially use anhydrous ethanol solvent to remove oil, multi-stage pure water cleaning, and constant temperature drying processes to remove surface dust, oil stains, and organic impurities, ensuring that the surface cleanliness meets the requirements of laser processing.

[0020] Step 2, Laser Modification Treatment: Ultrafast femtosecond laser is used to irradiate the interior of the glass substrate in a directional manner to form a through-type modification channel along the thickness direction. The laser parameters are adjusted to achieve a 10μm forming aperture and a depth-to-width ratio of 30:1, providing a preset path for subsequent selective etching.

[0021] Step 3, Environmentally friendly strong alkaline wet etching: The modified substrate is immersed in a fluorine-free environmentally friendly strong alkaline etching solution. The etching temperature is kept constant at 100℃. A two-stage step etching process is adopted. The first stage removes the core area modified by laser, and the second stage modifies the hole wall morphology. An intermediate water washing and descaling process is set between the two stages. The etching solution is continuously circulated and filtered during the etching process to reduce silicon scale deposition.

[0022] Step 4, Neutralization Cleaning and Drying: After etching, acid neutralization, multi-stage pure water ultrasonic cleaning, low-speed draining, and constant temperature drying are performed in sequence to remove residual alkaline solution and avoid corrosion of the inner wall of the through hole.

[0023] Step 5, Through-hole inspection: High-precision visual inspection equipment is used to detect parameters such as hole diameter and hole wall roundness in multi-modal imaging mode to screen qualified substrates. In this embodiment, the through holes are free of defects such as leaks and micro-cracks on the inner wall and are judged to be qualified.

[0024] Step 6, Metallization treatment: Qualified substrates are sequentially subjected to plasma activation, copper seed layer deposition, and then electroplating to fill conductive metal, thereby improving the coverage of the metal layer on the sidewalls of the through holes and the interfacial bonding strength.

[0025] Example 2 This embodiment provides an environmentally friendly strong alkaline solution wet etching method for TGV glass through-holes in optoelectronic co-packaging integration processes. The specific steps are as follows: Step 1: Substrate pretreatment: Select a suitable aluminosilicate glass substrate, and sequentially use acetone solvent to remove oil, multi-stage pure water cleaning, and constant temperature drying to remove surface impurities and ensure that the surface cleanliness meets the standards.

[0026] Step 2, Laser Modification Treatment: Ultrafast femtosecond laser is used to irradiate the interior of the substrate in a directional manner to form a through-type modification channel. The laser parameters are adjusted to achieve a 5μm forming hole diameter and a depth-to-width ratio of 40:1, which meets the requirements for small-size through-hole processing.

[0027] Step 3, Environmentally friendly strong alkaline wet etching: The modified substrate is immersed in a fluorine-free environmentally friendly strong alkaline etching solution. The etching temperature is kept constant at 85℃. A two-stage step etching process is adopted, with an intermediate water washing and descaling process set between the two stages. The etching solution is continuously circulated and filtered to reduce silicon scale deposition.

[0028] Step 4, Neutralization, Cleaning and Drying: The process involves acid neutralization, multi-stage ultrasonic cleaning with pure water, low-speed draining, and constant-temperature drying to thoroughly remove residual chemicals.

[0029] Step 5: Through-hole inspection: High-precision visual inspection equipment is used to inspect various parameters of the through-hole in multimodal imaging mode. In this embodiment, the through-hole has no defects and is judged to be a qualified product.

[0030] Step 6, Metallization: Qualified substrates are sequentially subjected to plasma activation, titanium seed layer deposition, and then filled with conductive metal through electroplating to complete the through-hole metallization process.

[0031] Example 3 This embodiment provides an environmentally friendly strong alkaline solution wet etching method for TGV glass through-holes, suitable for integrated fabrication processes of RF passive devices and microelectromechanical sensor substrates. The specific steps are as follows: Step 1: Substrate pretreatment: Select a suitable quartz glass substrate, and sequentially use anhydrous ethanol solvent to remove oil, multi-stage pure water cleaning, and constant temperature drying to remove surface impurities and ensure smooth subsequent processing.

[0032] Step 2, Laser Modification Treatment: Ultrafast femtosecond laser is used to irradiate the interior of the substrate in a directional manner to form a through-type modification channel. The laser parameters are adjusted to achieve a 30μm forming aperture and a depth-to-width ratio of 25:1.

[0033] Step 3, Environmentally friendly strong alkaline wet etching: The modified substrate is immersed in a fluorine-free environmentally friendly strong alkaline etching solution. The etching temperature is kept constant at 115℃. A two-stage step etching process is adopted, with an intermediate water washing and descaling process set between the two stages. The etching solution is continuously circulated and filtered to avoid silicon scale deposition affecting the processing quality.

[0034] Step 4, Neutralization, Cleaning and Drying: Complete acid neutralization, multi-stage pure water ultrasonic cleaning, low-speed draining, and constant temperature drying to remove residual alkaline solution.

[0035] Step 5, Through-hole inspection: High-precision visual inspection equipment is used to inspect various parameters of the through-hole in multi-modal imaging mode. In this embodiment, the through-hole is free of defects such as leaks and micro-cracks on the inner wall, and is judged to be qualified.

[0036] Step 6, Metallization: Qualified substrates are sequentially subjected to plasma activation, silver seed layer deposition, and then electroplating to fill conductive metal, thus completing the through-hole metallization process.

[0037] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for wet etching of through-holes in TGV glass using an environmentally friendly strong alkaline solution, characterized in that... Includes the following steps: Step 1: Substrate pretreatment: Select a glass substrate suitable for through-hole processing, and process it sequentially with solvent degreasing, multi-stage pure water cleaning, and constant temperature drying to thoroughly remove dust, oil and organic impurities adhering to the substrate surface, ensuring that the surface cleanliness of the substrate meets the requirements of subsequent laser processing. Step 2, Laser Modification Treatment: Ultrafast femtosecond laser is used to irradiate the interior of the glass substrate in a directional manner, and continuous etching is performed along the thickness direction of the substrate to form a through-type modification channel. The modified area can significantly improve the etching rate and provide a preset etching path for subsequent selective wet etching. Step 3, Environmentally friendly strong alkaline wet etching: The laser-modified glass substrate is immersed in a fluorine-free environmentally friendly strong alkaline etching solution system for constant temperature etching. The modified channel is dissolved in a directional manner by relying on the difference in corrosion rate between the modified channel and the ordinary glass body, and finally a complete and through glass hole is formed. The etching solution is continuously circulated, filtered and purified during the etching process. Step 4, Neutralization Cleaning and Drying: After etching, the substrate undergoes acid neutralization, multi-stage pure water ultrasonic cleaning, low-speed draining, and constant temperature drying processes in sequence to completely remove residual alkaline solution from the substrate surface and prevent residual solution from corroding the inner wall of the through hole. Step 5: Inspection of the appearance and dimensions of the through holes: The formed through holes are fully scanned and inspected using high-precision visual inspection equipment. The hole diameter, hole wall roundness, hole position coordinate accuracy, leakage holes and micro-cracks on the inner wall are verified simultaneously, and qualified glass substrates are sorted and screened.

2. The method for wet etching of TGV glass through holes using environmentally friendly strong alkaline chemicals according to claim 1, characterized in that, In step two, the minimum forming aperture of 5μm is achieved by adjusting the laser output parameters, and the depth-to-width ratio of the through hole is controlled to above 20:1 by adjusting the laser processing parameters.

3. The method for wet etching of TGV glass through holes using an environmentally friendly strong alkaline solution according to claim 1, characterized in that, In step three, the etching temperature is kept constant at 80-120℃, and the etching solution is continuously circulated and filtered during the etching process to reduce the deposition of silicon scale on the inner wall of the through hole and in the etching tank.

4. The method for wet etching of TGV glass through holes using an environmentally friendly strong alkaline solution according to claim 3, characterized in that, The environmentally friendly strong alkaline etching solution is free of fluorides. The system components include strong alkali, complexing stabilizer, penetrating wetting agent, and silicon scale inhibitor. It relies on the synergistic effect of the component ratio to reduce the roughness of the inner wall of the through hole and accurately control the taper of the through hole.

5. The method for wet etching of TGV glass through holes using an environmentally friendly strong alkaline solution according to claim 3, characterized in that, Step 3 employs a two-stage step-by-step etching process. The first stage of etching removes the laser-modified core area, while the second stage of fine-tuning etching modifies the morphology of the inner wall of the through hole. An intermediate water washing and descaling process is set between the two etching stages.

6. The method for wet etching of TGV glass through holes using an environmentally friendly strong alkaline solution according to claim 1, characterized in that, Step 5 employs a multimodal imaging detection mode to simultaneously acquire multi-dimensional data on the through-hole size, contour, and inner wall defects, achieving integrated detection of the through-hole's full size and defects.

7. The method for wet etching of TGV glass through holes using an environmentally friendly strong alkaline solution according to claim 1, characterized in that, After the through-hole inspection is completed, the glass substrate undergoes plasma activation and metal seed layer deposition processes in sequence to form a uniformly attached metal substrate on the inner wall of the through-hole.

8. The method for wet etching of TGV glass through holes using an environmentally friendly strong alkaline solution according to claim 7, characterized in that, After the metal seed layer is deposited, an electroplating filling process is used to fill the through holes with conductive metal, thereby improving the metal layer coverage and interface bonding strength of the through hole sidewalls.

9. The TGV glass through-hole substrate prepared by the processing method according to any one of claims 1 to 8, characterized in that, The substrate is suitable for the integration process of three-dimensional advanced packaging, optoelectronic co-packaging, radio frequency passive devices, and microelectromechanical sensor substrates.

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