Method for improving surface roughness of glass substrate after laser drilling

Abstract

The invention relates to the technical field of glass surface treatment, in particular to a method for improving the surface roughness of a glass substrate after laser drilling. The method comprises the following steps: S1, performing laser drilling on a glass substrate by using large-aperture small-energy CO2 laser to form a through hole; s2, putting the glass substrate subjected to laser drilling into a reactive plasma system, and introducing etching gas to etch the glass substrate; s3, performing ultrasonic cleaning on the glass substrate subjected to plasma treatment by using deionized water or ethanol to remove surface residues; s4, the surface of the glass substrate is blow-dried with clean air, and water stain residues are avoided; s5, observing the surface morphology of the hole wall by using a scanning electron microscope or an optical microscope, and evaluating the plasma treatment effect; and S6, measuring the roughness of the surface of the hole wall by using a surface roughness meter, and evaluating whether the target requirement is met or not. The method is environmentally friendly, efficient and wide in application range, and the quality of the treated glass is better.

Description

Technical Field

[0001] The invention relates to the technical field of glass surface treatment, and in particular to a method for improving the surface roughness of a glass substrate after laser drilling. Background Art

[0002] At present, a method for improving the surface roughness of a glass substrate after laser drilling mainly includes chemical etching and mechanical grinding. Although the chemical etching method can effectively improve the surface roughness, a Chinese patent with publication number CN119581331A discloses a method for optimizing the roughness of the sidewall of a glass through hole, which uses a femtosecond laser to uniformly and deeply change the material structure of the prefabricated through hole area in a thermal cycle, thereby significantly improving its sensitivity to chemical etching and making it easier to be uniformly removed; by optimizing the components and proportions of the etching solution, in the subsequent chemical etching stage, the etching solution uniformly covers and acts on the material surface of the prefabricated through hole modified area, corrodes the modified material at a uniform rate, and removes the corrosion residue in time. By controlling the temperature of the etching solution and the ultrasonic power, the mixing and reaction uniformity of the etching solution are enhanced, and uniform and fine etching of the prefabricated through-hole modified area is achieved. For example, a Chinese patent with publication number CN119409424A discloses a method for roughening the surface of a glass substrate, which can preliminarily adjust the roughness of the surface of the glass substrate by immersing the rinsed glass substrate in a first immersion KOH solution pool for pre-roughening treatment, so that it is easier to accept the subsequent secondary roughening treatment, and the glass substrate roughened by the first immersion is placed in a second immersion KOH solution pool for secondary roughening treatment, and an ultrasonic generator is used to uniformly diffuse the KOH solution in the second immersion KOH solution pool. At the same time, the KOH solution is stirred by a stirring device so that the KOH solution in the second immersion KOH solution pool can uniformly etch the glass substrate, thereby improving the etching efficiency and quality of the roughened glass substrate. However, the above method has the problems of environmental pollution and difficulty in process control; the mechanical grinding method is easy to cause surface damage, affecting the mechanical strength of the glass substrate. Summary of the invention

[0003] The technical problem to be solved by the present invention is: to overcome the shortcomings of the prior art, to provide a method for improving the surface roughness of a glass substrate after laser drilling, to use plasma to treat the surface of the substrate, and to solve the problems of environmental pollution, difficulty in process control, and surface damage existing in the prior art.

[0004] The technical solution of the present invention is: A method for improving the surface roughness of a glass substrate after laser drilling, comprising the following steps: S1, glass substrate is drilled by laser using large aperture and low energy CO 2 Through holes are formed after laser treatment; S2. Place the laser-drilled glass substrate into a reactive plasma system and introduce etching gas to etch the glass substrate. The etching process is divided into three stages: In the first etching stage, the etching gases are oxygen and argon, which are introduced simultaneously, with a ratio of oxygen to argon of 4:6; In the second etching stage, the etching gases are oxygen, carbon tetrafluoride and argon. Oxygen, carbon tetrafluoride and argon are introduced at the same time, and the ratio of oxygen, carbon tetrafluoride and argon is 2:2:6; In the third etching stage, the etching gas is oxygen.

[0005] Preferably, the RF power supply power in the first etching stage is 8.5 KW, the RF power supply power in the second etching stage is 7.5 KW, and the RF power supply power in the third etching stage is 6.5 KW.

[0006] Preferably, the etching time of the first etching stage is 10 minutes, the etching time of the second etching stage is 27 minutes, and the etching time of the third etching stage is 3 minutes.

[0007] Preferably, the steps further include: S3, using deionized water or ethanol to ultrasonically clean the glass substrate after the plasma treatment to remove surface residues; S4. Use clean air to dry the surface of the glass substrate to avoid water stains; S5. Observe the surface morphology of the pore wall using a scanning electron microscope or an optical microscope to evaluate the plasma treatment effect; S6. Use a surface roughness meter to measure the roughness of the hole wall surface and evaluate whether the target requirements are met.

[0008] Preferably, the temperature of the vacuum chamber in the first etching stage is 100°C, the temperature of the vacuum chamber in the second etching stage is 100°C, and the temperature of the vacuum chamber in the third etching stage is 80°C.

[0009] Preferably, the vacuum pressure of the etching process in step S2 is maintained at 220 mtorr.

[0010] Preferably, the gas flow rates of oxygen and argon in the first etching stage are 1000 sccm and 1500 sccm respectively, the gas flow rates of oxygen, carbon tetrafluoride and argon in the second etching stage are 500 sccm, 500 sccm and 1500 sccm respectively, and the gas flow rate of oxygen in the third etching stage is 2500 sccm.

[0011] Preferably, the temperature control accuracy of the vacuum chamber temperature is ±2° C., and the cooling rate in the third etching stage is 5-10° C. / min.

[0012] Preferably, the reactive plasma system is an inductively coupled plasma (ICP) system, the electrode spacing of which is 30-50 mm and the radio frequency is 13.56 MHz.

[0013] Compared with the prior art, the present invention has the following beneficial effects: Environmentally friendly and efficient: The present invention adopts plasma treatment technology, does not need to use chemical reagents, avoids environmental pollution, and has a simple process and is easy to control.

[0014] Good surface quality: Plasma treatment can form a uniform micro-nano rough structure on the hole wall surface of the glass substrate after laser drilling, effectively improving the surface roughness and enhancing the adhesion of the metallization layer.

[0015] Wide scope of application: This application is applicable to various types of glass substrates and has good universality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 It is a schematic diagram of the process of the present invention.

[0018] Figure 2 It is a flow chart of the etching stage of the present invention.

[0019] Figure 3 The present invention provides a low-magnification scanning electron microscope photograph of a glass substrate prepared in a method for improving the surface roughness of a glass substrate after laser drilling.

[0020] Figure 4 The present invention provides a high-power scanning electron microscope photograph of a glass substrate prepared in a method for improving the surface roughness of a glass substrate after laser drilling.

[0021] Figure 5 This is a low-magnification scanning electron microscope photograph of the surface of a glass substrate after mechanical grinding. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0023] Example like Figure 1-Figure 4 As shown, this embodiment provides a method for improving the surface roughness of a glass substrate after laser drilling, comprising the following steps: S1, glass substrate is drilled by laser using large aperture and low energy CO 2 Through holes are formed after laser treatment; S2. Place the laser-drilled glass substrate into a reactive plasma system and introduce etching gas to etch the glass substrate. The etching process is divided into three stages: In the first etching stage, the etching gases are oxygen and argon, which are introduced simultaneously, with the ratio of oxygen to argon being 4:6. In this stage, oxygen and argon are mainly used to clean foreign matter on the surface of the glass substrate and improve the hydrophilicity of the glass substrate. At the same time, the mixed gas of oxygen and argon is convenient for exciting more plasma at the same time, thereby improving the efficiency of cleaning foreign matter on the substrate and the hydrophilic effect. The argon gas pre-treats the surface of the glass substrate by physical collision.

[0024] In the second etching stage, the etching gases are oxygen, carbon tetrafluoride and argon. Oxygen, carbon tetrafluoride and argon are introduced at the same time, and the ratio of oxygen, carbon tetrafluoride and argon is 2:2:6. The addition of oxygen to the mixed gas in this stage is to better stimulate the plasma of oxygen and argon. The argon plasma state mainly attacks the glass substrate in a physical collision manner, and the carbon tetrafluoride plasma state mainly attacks the glass substrate in a chemical etching manner. The three are combined with physical collision as the main method and chemical etching as the auxiliary method, thereby uniformly improving the roughness of the surface of the glass substrate and the inside of the hole after laser drilling, which is convenient for enhancing the adhesion of the metallization layer.

[0025] In the third etching stage, the etching gas is oxygen. 2 Once again, ensure that the wettability of the surface and the inside of the glass substrate after laser drilling is convenient for cleaning and drying in subsequent processes, and remove the residual carbon tetrafluoride and argon in the reaction chamber and on the substrate to ensure that no gas will cause harm to personnel and equipment when the hatch is opened. At the same time, the chamber is cooled by temperature control to facilitate the removal of the glass substrate after opening the hatch, thereby improving efficiency.

[0026] like Figure 5 As shown, mechanical grinding can easily cause surface damage and affect the mechanical strength of the glass substrate.

[0027] Preferably, the RF power in the first etching stage is 8.5KW, the RF power in the second etching stage is 8.5KW, and the RF power in the third etching stage is 6.5KW. By controlling the RF power, the energy density of the plasma can be controlled, affecting the etching rate and surface morphology.

[0028] Preferably, the etching time of the first etching stage is 10 minutes, the etching time of the second etching stage is 27 minutes, and the etching time of the third etching stage is 3 minutes. According to the target roughness, the processing time is controlled to avoid excessive etching causing damage to the hole wall.

[0029] Preferably, the steps further include: S3, using deionized water or ethanol to ultrasonically clean the glass substrate after the plasma treatment to remove surface residues; S4. Use clean air to dry the surface of the glass substrate to avoid water stains; S5. Observe the surface morphology of the pore wall using a scanning electron microscope or an optical microscope to evaluate the plasma treatment effect; S6. Use a surface roughness meter to measure the roughness of the hole wall surface and evaluate whether the target requirements are met.

[0030] Preferably, the temperature of the vacuum chamber in the first etching stage is 100°C, the temperature of the vacuum chamber in the second etching stage is 100°C, and the temperature of the vacuum chamber in the third etching stage is 80°C.

[0031] Preferably, the vacuum pressure of the etching process in step S2 is maintained at 220 mtorr. By controlling the vacuum pressure, the pressure of the reaction gas can be controlled, which affects the uniformity and stability of the plasma.

[0032] Preferably, the gas flow rates of oxygen and argon in the first etching stage are 1000 sccm and 1500 sccm respectively, the gas flow rates of oxygen, carbon tetrafluoride and argon in the second etching stage are 500 sccm, 500 sccm and 1500 sccm respectively, and the gas flow rate of oxygen in the third etching stage is 2500 sccm.

[0033] Preferably, the temperature control accuracy of the vacuum chamber temperature is ±2° C., and the cooling rate in the third etching stage is 5-10° C. / min.

[0034] Preferably, the reactive plasma system is an inductively coupled plasma (ICP) system, the electrode spacing of which is 30-50 mm and the radio frequency is 13.56 MHz.

[0035] According to the technical features of the invention, the following comparative examples can be set to verify the synergy and technical effects of each stage: Comparative Example 1 Only the second and third etching stages are performed.

[0036] Results: The foreign matter remaining on the substrate surface caused uneven etching, the roughness difference in the hole was greater than 20%, and the metal adhesion decreased by 35%.

[0037] Conclusion: The necessity of the first stage argon-oxygen mixed pretreatment for surface cleaning and hydrophilicity.

[0038] Comparative Example 2 The gas ratio in the second etching stage is O 2 :Ar=2:8.

[0039] The hole wall roughness Ra value is only 1.2μm (the original plan is 2.8μm), and the metal layer peeling force is <5N / cm² (the original plan is >8N / cm²).

[0040] Proof: CF in this application 4 The key role of chemical etching in three-dimensional roughness construction.

[0041] Comparative Example 3 The etching sequence was changed to the third → second → first stage.

[0042] Residual CF 4 The gas caused the surface contact angle to be greater than 50° (the original solution was less than 10°), and the cleaning and drying time was extended by 2 times.

[0043] Embodiment: The sequence of stages is unique to the process logic of this application.

[0044] Comparative Example 4 All stages use only O 2 .

[0045] The orifice diameter deviation is ±8μm (original solution ±2μm), and the etching rate decreases by 60%.

[0046] Verification: Physical-chemical synergistic effect of mixed gases.

[0047] Comparative Example 5 The oxygen purge stage was omitted.

[0048] Results: CF remained in the cavity 4 Concentration>1000ppm (safety standard<1ppm), substrate moisture content>200ppm.

[0049] The influence of the terminal purification of the present invention on safety and dryness is highlighted.

[0050] Comparative Example 6 Keep the chamber temperature at 150℃ and open the chamber directly.

[0051] The waiting time for taking out the substrate was extended to 30 minutes (the original plan was to take it out immediately), and the incidence of microcracks caused by thermal stress was >5%.

[0052] Proof: Temperature control can improve production efficiency.

[0053] Table 1: Comparative Examples 1-6 and the corresponding data table of the present invention

[0054] Based on the above comparative examples, the following conclusions can be drawn: Through staged gas ratio and physical-chemical synergy, the present invention shows significant advantages over the comparative example in terms of adhesion strength (increased by 72%), hole shape consistency (deviation reduced by 75%), production safety (zero harmful gas residue) and process efficiency (cycle time shortened by 40%). In particular, the three-stage temperature gradient control (100℃→100℃→80℃) reduces the incidence of thermal stress cracks from 5% to 0.3%, verifying the systematic innovation value of the technical solution.

[0055] Working principle: The present invention optimizes the surface roughness of a glass substrate after laser drilling through a phased reactive plasma etching process: in the first phase, a mixed gas of oxygen and argon is used to remove surface foreign matter and improve hydrophilicity through physical bombardment of argon ions; in the second phase, carbon tetrafluoride is introduced, and a uniform rough structure is formed on the hole wall in combination with the synergistic effect of argon physical collision and fluorine free radical chemical etching to enhance metal adhesion; in the third phase, pure oxygen is switched to remove residual harmful gases and optimize surface wettability, and efficient etching and process safety are achieved through RF power gradient control, temperature step adjustment and constant vacuum pressure; finally, ultrasonic cleaning, drying and surface morphology detection are performed to ensure that the hole wall roughness meets the standard.

[0056] Although the present invention has been described in detail by referring to the accompanying drawings and in combination with the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions shall be within the scope of the present invention. Any person of ordinary skill in the art may easily think of changes or substitutions within the technical scope disclosed by the present invention, and these shall be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A method for improving the surface roughness of a glass substrate after laser drilling, characterized in that: The steps include: S1. Through holes are formed on the glass substrate by laser drilling using a large aperture and low energy CO2 laser; S2. Place the laser-drilled glass substrate into a reactive plasma system and introduce etching gas to etch the glass substrate. The etching process is divided into three stages: In the first etching stage, the etching gases are oxygen and argon, which are introduced simultaneously, with a ratio of oxygen to argon of 4:6; In the second etching stage, the etching gases are oxygen, carbon tetrafluoride and argon. Oxygen, carbon tetrafluoride and argon are introduced at the same time, and the ratio of oxygen, carbon tetrafluoride and argon is 2:2:6; In the third etching stage, the etching gas is oxygen.

2. A method for improving the surface roughness of a glass substrate after laser drilling as claimed in claim 1, characterized in that: The RF power in the first etching stage is 8.5 KW, the RF power in the second etching stage is 7.5 KW, and the RF power in the third etching stage is 6.5 KW.

3. The method for improving the surface roughness of a glass substrate after laser drilling as claimed in claim 1, characterized in that: The etching time of the first etching stage is 10 minutes, the etching time of the second etching stage is 27 minutes, and the etching time of the third etching stage is 3 minutes.

4. The method for improving the surface roughness of a glass substrate after laser drilling as claimed in claim 1, characterized in that: The steps also include: S3, using deionized water or ethanol to ultrasonically clean the glass substrate after the plasma treatment to remove surface residues; S4. Use clean air to dry the surface of the glass substrate to avoid water stains; S5. Observe the surface morphology of the pore wall using a scanning electron microscope or an optical microscope to evaluate the plasma treatment effect; S6. Use a surface roughness meter to measure the roughness of the hole wall surface and evaluate whether the target requirements are met.

5. The method for improving the surface roughness of a glass substrate after laser drilling as claimed in claim 1, characterized in that: The temperature of the vacuum chamber in the first etching stage is 100° C., the temperature of the vacuum chamber in the second etching stage is 100° C., and the temperature of the vacuum chamber in the third etching stage is 80° C.

6. The method for improving the surface roughness of a glass substrate after laser drilling as claimed in claim 1, characterized in that: The vacuum pressure of the etching process in step S2 is maintained at 220 mtorr.

7. The method for improving the surface roughness of a glass substrate after laser drilling as claimed in claim 1, characterized in that: In the first etching stage, the gas flow rates of oxygen and argon are 1000 sccm and 1500 sccm respectively; in the second etching stage, the gas flow rates of oxygen, carbon tetrafluoride and argon are 500 sccm, 500 sccm and 1500 sccm respectively; and in the third etching stage, the flow rate of oxygen is 2500 sccm.

8. The method for improving the surface roughness of a glass substrate after laser drilling as claimed in claim 5, characterized in that: The temperature control accuracy of the vacuum chamber temperature is ±2°C, and the cooling rate in the third etching stage is 5-10°C / min.

9. The method for improving the surface roughness of a glass substrate after laser drilling as claimed in claim 1, characterized in that: The reactive plasma system is an inductively coupled plasma (ICP) system, the electrode spacing is 30-50 mm, and the radio frequency is 13.56 MHz.

Images