Preparation method of high-precision glass through hole based on PTR glass

Abstract

The invention discloses a preparation method of a high-precision glass through hole based on PTR glass. Comprising the following steps: step 1, carrying out high-temperature melting, casting molding and annealing treatment on a glass raw material to obtain a PTR glass substrate; 2, cutting the PTR glass substrate, polishing the two surfaces of the PTR glass substrate, and carrying out patterning exposure by utilizing ultraviolet light and a mask to obtain exposed glass; 3, carrying out gradient heat treatment on the exposed glass to obtain microcrystalline glass; and step 4, etching the microcrystalline glass in a hydrofluoric acid solution to obtain the glass through hole with the high depth-diameter ratio. The method has the beneficial effects that by optimizing the material formula and the technological process, the problems that in a traditional method, the hole diameter is not uniform, the inner wall is rough and the machining cost is high are solved, and the through hole machining precision, stability and the depth-diameter ratio are remarkably improved. The method is suitable for the fields of microelectronic packaging, optical connectors, high-frequency devices, microfluidic chips and the like, and has a wide industrial application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of glass processing, and specifically, relates to a method for preparing high-precision glass through-holes based on PTR glass. Background Art

[0002] In the fields of microelectronic packaging, optical devices, and microfluidic device manufacturing, glass through-holes serve as key structural components, performing multiple functions such as conducting electricity, light, and liquid. They are widely used in high-tech fields such as semiconductor chip packaging, optical waveguide devices, micro sensors, and lab-on-a-chip. Glass materials have unique advantages in through-hole manufacturing due to their excellent chemical stability, mechanical strength, and light transmittance. However, the high hardness and brittleness of glass pose significant challenges to through-hole processing, demanding higher precision and efficiency in the preparation process. There are mainly three technical routes for traditional glass through-hole preparation methods: The mechanical drilling method relies on mechanical drills for processing. Although the operation is simple, it has high requirements for equipment. During the processing, cracks are easily induced, resulting in uneven hole diameters and low efficiency. In particular, it is difficult to achieve the processing of high aspect ratio through-holes. Laser drilling technology realizes non-contact processing through local laser heating, but it will generate a heat-affected zone, causing problems such as rough hole walls and crack propagation. The chemical etching method uses mask technology and wet chemical etching to dissolve glass materials. Although it can obtain relatively smooth hole walls, the process flow is complex and the efficiency is low, and it has strict requirements for material selectivity.

[0003] In recent years, photorefractive (PTR) glass has become a research hotspot due to its unique photosensitive properties. This material undergoes local refraction under ultraviolet light irradiation, forming regions with different chemical stabilities. Precise through-hole processing can be achieved through subsequent heat treatment and chemical etching. This method shows significant advantages in improving processing precision, controlling hole diameter uniformity, and improving hole wall smoothness. However, there are still obvious deficiencies in the existing PTR glass through-hole preparation technologies: The process flow lacks systematic optimization, making it difficult to balance the processing requirements of high precision and high efficiency; the synergistic effect of heat treatment and etching processes is insufficient, restricting the preparation of high aspect ratio and smooth hole wall through-holes; at the same time, there is a lack of efficient and stable processing methods suitable for large-scale production.

[0004] Existing patented technologies such as CN113045209A propose a method for processing glass through-holes, but the etching solution formula used is complex and has poor stability, and the multi-step process results in low production efficiency; while the photosensitive glass-ceramic exposure method disclosed in CN117706878A requires additional metal layer preparation and stripping processes, which not only increases the process complexity but also significantly raises the production cost.

[0005] Therefore, to solve the above problems, the present invention provides a method for preparing high-precision glass through-holes based on PTR glass. Summary of the Invention

[0006] The object of the present invention is to overcome the defects of the prior art and provide a method for preparing high-precision glass vias based on PTR glass.

[0007] The object of the present invention can be achieved by the following technical solutions: A method for preparing high-precision glass vias based on PTR glass: First, the PTR glass is selectively exposed by ultraviolet light combined with a mask, causing photorefraction in a specific area. Subsequently, through gradient heat treatment, the exposed area undergoes crystallization, forming a phase separation structure with different chemical stabilities. Finally, through selective chemical etching, the crystallized area is preferentially dissolved, thereby forming a high-precision and high aspect ratio via structure, specifically as follows: Step 1: The glass raw materials are melted at high temperature, cast and annealed to obtain a PTR glass substrate; Step 2: After cutting and double-sided polishing the PTR glass substrate, it is pattern-exposed using ultraviolet light combined with a mask to obtain an exposed glass; Step 3: The exposed glass is subjected to gradient heat treatment to obtain crystallized glass; Step 4: The crystallized glass is etched in a hydrofluoric acid solution to obtain a glass via with a high aspect ratio.

[0008] Preferably, the glass raw materials are composed of the following components: 50–70wt% SiO2, 7–15wt% Na2O, 1–4wt% KBr, 3–8wt% Al2O3, 5–15wt% NaF, 4–8wt% ZnO, 0.1–0.5wt% Sb2O3, 0.1-0.5wt% La2O3, 0.1-0.5wt% TiO2, 0.02–0.1wt% CeO2, 0.02–0.1wt% Ag2O.

[0009] Furthermore, the total content of Na2O and NaF is 10-20wt%, and the mass ratio of CeO2 to Ag2O is (1-2):1.

[0010] Preferably, the process parameters of the melting are: temperature 1400-1600 °C, time 2-4 h; the process parameters of the annealing are: temperature 400-600 °C, time 1-4 h.

[0011] Preferably, the process parameters of the pattern exposure are: the wavelength of the laser is 300-320 nm, the output power is 1-10 W, the exposure time is 10-60 s, and the exposure energy density is 1-10 J / cm 2 .

[0012] Preferably, the process parameters of the gradient heat treatment are as follows: at 450 - 550 °C, hold for 1 - 3 h, then heat up to 550 - 700 °C and hold for 1 - 3 h.

[0013] Preferably, the concentration of the hydrofluoric acid solution is 5 - 20 wt%; the etching time is 5 - 30 min.

[0014] Preferably, the etching process is carried out under ultrasonic assistance, and the ultrasonic frequency is 20 - 100 kHz.

[0015] Preferably, the aperture range of the through - hole is 30 - 100 µm, and the depth - to - diameter ratio range is (5 - 20):1.

[0016] Preferably, after the etching process is completed, ultrasonic cleaning technology can be used to treat the glass substrate to thoroughly remove the residual etching by - products and pollutants on the surface and in the through - holes; and subsequent coating or other surface treatments can be carried out on the through - holes as needed.

[0017] Compared with the prior art, the advantages of the present invention are as follows: (1) The present invention combines ultraviolet light - patterned and heat - treatment optimization technologies to achieve the processing of glass through - holes with a high depth - to - diameter ratio, breaking through the depth limitation of traditional processes and meeting the high - precision requirements of microelectronic packaging and optical devices; (2) By precisely controlling the heat - treatment and chemical - etching parameters, the present invention can obtain better through - holes and effectively avoid the problem of crack propagation in traditional methods; (3) The present invention organically combines light - patterned, heat - treatment, and selective chemical etching, simplifies the processing steps, improves the processing efficiency, and has high potential for industrial application; (4) The cost of the PTR glass material of the present invention is moderate, the material loss during the processing is small, the manufacturing cost is significantly reduced, and it is suitable for large - scale production. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0019] Figure 1 is a schematic process flow diagram for the preparation of glass through - holes; Figure 2 is a photograph of the heat - treated exposed area of the PTR glass substrate prepared in Example 1; Figure 3 is a photograph of the PTR glass substrate prepared in Example 2 after mask - plate exposure and heat - treatment; Figure 4 is a photograph of the PTR glass substrate prepared in Example 3 after mask - plate exposure, heat - treatment, and etching; Figure 5 Profile photographs of the unexposed and heat-treated exposed regions of the PTR glass substrate prepared in Example 3; Figure 6 XRD pattern of the PTR glass substrate prepared in Example 3; Figure 7 Photographs of the PTR glass substrate prepared in Example 4 after mask exposure, heat treatment, and etching; Figure 8 Profile photograph of the etched PTR glass prepared in Example 5. Detailed implementation manners

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0021] Example 1: A method for preparing a high-precision glass through-hole based on PTR glass (as Figure 1 shown) includes the following steps: Step 1: Melting the glass raw materials at 1500 °C for 3 h, then quickly casting and molding, and annealing at 500 °C for 2 h to obtain a PTR glass substrate; the glass raw materials are composed of the following components: 63 wt% SiO2, 10 wt% Na2O, 3 wt% KBr, 6 wt% Al2O3, 10 wt% NaF, 7 wt% ZnO, 0.3 wt% Sb2O3, 0.3 wt% La2O3, 0.3 wt% TiO2, 0.05 wt% CeO2, 0.05 wt% Ag2O; Step 2: Cutting the PTR glass substrate into 1 mm thick glass sheets, double-sided polishing, and then patterning exposure using ultraviolet light combined with a mask (exposing with a 310 nm wavelength laser for 30 s, and the aperture size of the mask is 80 µm) to obtain an exposed glass; Step 3: Gradient heat-treating the exposed glass (holding at 480 °C for 2 h, then heating to 550 °C and holding for 2 h) to obtain a microcrystalline glass; Step 4: Etching the microcrystalline glass in a 5% hydrofluoric acid solution for 10 min to form a through-hole with a diameter of 100 µm and a depth-to-diameter ratio of 10:1.

[0022] Figure 2It shows the comparison between the exposed area and the unexposed area of the prepared PTR glass in this embodiment after heat treatment. It can be clearly seen from the figure that the area exposed to ultraviolet light significantly darkens after gradient heat treatment, indicating that this area has been successfully microcrystallized, forming a phase separation structure with significant chemical activity differences. In contrast, the unexposed area shows no obvious change after heat treatment and maintains its original amorphous structure. This phenomenon fully demonstrates that PTR glass has excellent photosensitive properties and can achieve precise area-selective microcrystallization through ultraviolet light exposure and heat treatment, providing a basis for subsequent chemical etching.

[0023] Example 2: A method for preparing a high-precision glass through-hole based on PTR glass (as Figure 1 shown), comprising the following steps: Step 1: Melting the glass raw materials at 1500 °C for 3 h, then rapidly casting and molding, and annealing at 500 °C for 2 h to obtain a PTR glass substrate; the glass raw materials are composed of the following components: 61 wt% SiO2, 7 wt% Na2O, 4 wt% KBr, 8 wt% Al2O3, 12 wt% NaF, 7 wt% ZnO, 0.3 wt% Sb2O3, 0.3 wt% La2O3, 0.3 wt% TiO2, 0.05 wt% CeO2, 0.05 wt% Ag2O; Step 2: Cutting the PTR glass substrate into 1-mm-thick glass sheets, double-sided polishing, and then using ultraviolet light combined with a mask for patterned exposure (exposing with a 310-nm wavelength laser for 30 s, and the aperture size of the mask is 80 µm) to obtain an exposed glass; Step 3: Gradient heat-treating the exposed glass (at 480 °C, holding for 2 h, then heating to 550 °C and holding for 2 h) to obtain microcrystallized glass; Step 4: Etching the microcrystallized glass in a 5% hydrofluoric acid solution for 10 min to form a through-hole with a diameter of 100 µm and a depth-to-diameter ratio of 10:1.

[0024] Figure 3 It shows a comparison diagram of the original PTR glass sheet prepared in this embodiment and that after mask exposure and gradient heat treatment. It can be clearly observed from the figure that the area exposed to ultraviolet light significantly darkens after gradient heat treatment, indicating that this area has been successfully microcrystallized, forming a phase separation structure with significant chemical activity differences. In addition, the boundary between the microcrystallized area and the unexposed area is clear and distinct, further demonstrating the excellent photosensitive properties and area selectivity of PTR glass under ultraviolet light exposure and heat treatment conditions. This clear phase separation structure provides an ideal basis for subsequent selective chemical etching, ensuring high precision and high quality in through-hole processing.

[0025] Example 3: A method for preparing a high-precision glass through-hole based on PTR glass (as shown in Figure 1 ), comprising the following steps: Step 1: Melting the glass raw materials at 1500 °C for 2.5 h, then rapidly casting and molding, and annealing at 500 °C for 2 h to obtain a PTR glass substrate; the glass raw materials are composed of the following components: 64 wt% SiO2, 12 wt% Na2O, 3 wt% KBr, 5 wt% Al2O3, 8 wt% NaF, 7 wt% ZnO, 0.3 wt% Sb2O3, 0.3 wt% La2O3, 0.3 wt% TiO2, 0.05 wt% CeO2, 0.05 wt% Ag2O; Step 2: Cutting the PTR glass substrate into 1 mm thick glass sheets, double-sided polishing, and then patterning and exposing using ultraviolet light combined with a mask (exposing with a 310 nm wavelength laser for 30 s, and the aperture size of the mask is 40 µm) to obtain an exposed glass; Step 3: Gradient heat-treating the exposed glass (at 480 °C, holding for 2 h, then heating to 550 °C and holding for 2 h) to obtain a microcrystallized glass; Step 4: Etching the microcrystallized glass in a 10% hydrofluoric acid solution for 10 min to form a through-hole with a diameter of 50 µm and a depth-to-diameter ratio of 20:1.

[0026] Figure 4 Shows the comparison diagrams of the original PTR glass prepared in this example, after mask exposure, gradient heat treatment, and etching. It can be clearly observed from the figure that the area exposed to ultraviolet light has achieved microcrystallization after gradient heat treatment. In addition, after etching, the exposed crystallized area is completely removed to form a through-hole, and the unexposed area is retained.

[0027] Figure 5 Shows the profilometer comparison photos of the PTR glass prepared in this example in the ultraviolet-exposed area and the unexposed area after heat treatment. As shown in the figure, obvious crystallization morphologies are formed in the exposed areas after heat treatment, and it can be observed that larger crystal grains are evenly distributed, while the unexposed areas maintain the amorphous characteristics. This result confirms that the PTR glass can form a stable microcrystallized structure under ultraviolet light induction, and this crystallization process has significant regional selectivity. Through the synergistic effect of ultraviolet exposure and heat treatment, the present invention has successfully achieved the controllable crystallization of the glass microstructure.

[0028] Figure 6The XRD pattern of the PTR glass prepared in this example is shown. As can be seen from the figure, the patterns after exposure and the original PTR glass sheet both show typical amorphous characteristic curves, and no obvious crystal diffraction peaks appear, indicating that the crystallization is not induced during the exposure process. However, after exposure and gradient heat treatment, characteristic diffraction peaks of NaF appear in the XRD pattern, indicating that crystallization occurs in the exposed area during the heat treatment process. This result further verifies the photorefractive property of PTR glass, that is, the ultraviolet light-exposed area can selectively crystallize after heat treatment, providing a basis for subsequent chemical etching.

[0029] Example 4: A method for preparing a high-precision glass through-hole based on PTR glass (as Figure 1 shown), including the following steps: Step 1: Melting the glass raw materials at 1550 °C for 3 h, then quickly casting and molding, and annealing at 500 °C for 2 h to obtain a PTR glass substrate; the glass raw materials are composed of the following components: 67 wt% SiO2, 10 wt% Na2O, 4 wt% KBr, 6 wt% Al2O3, 5 wt% NaF, 7 wt% ZnO, 0.2 wt% Sb2O3, 0.3 wt% La2O3, 0.3 wt% TiO2, 0.1 wt% CeO2, 0.1 wt% Ag2O; Step 2: Cutting the PTR glass substrate into glass sheets with a thickness of 0.5 mm, double-sided polishing, and then using ultraviolet light combined with a mask for patterned exposure (using a 310 nm wavelength laser for exposure, the exposure time is 30 s, and the aperture size of the mask is 80 µm) to obtain the exposed glass; Step 3: Gradient heat-treating the exposed glass (at 500 °C, holding for 2 h, then heating to 600 °C, holding for 2 h) to obtain the microcrystallized glass; Step 4: Etching the microcrystallized glass in a 10% hydrofluoric acid solution for 10 min to form a through-hole with a diameter of 100 µm and a depth-to-diameter ratio of 5:1.

[0030] Figure 7 The comparison diagrams of the original PTR glass sheet prepared in this example, after mask exposure, gradient heat treatment, and etching are shown. It can be clearly observed from the figure that the area exposed to ultraviolet light is microcrystallized after gradient heat treatment. In addition, after etching, the crystallized area is completely removed to form a through-hole.

[0031] Example 5: A method for preparing a high-precision glass through-hole based on PTR glass (as Figure 1 shown), including the following steps: Step 1: Melting the glass raw materials at 1450 °C for 3 h, then rapidly casting and molding, and annealing at 500 °C for 2 h to obtain a PTR glass substrate; the glass raw materials are composed of the following components: 62 wt% SiO2, 5 wt% Na2O, 4 wt% KBr, 6 wt% Al2O3, 15 wt% NaF, 7 wt% ZnO, 0.3 wt% Sb2O3, 0.2 wt% La2O3, 0.2 wt% TiO2, 0.2 wt% CeO2, 0.1 wt% Ag2O; Step 2: Cutting the PTR glass substrate into glass sheets with a thickness of 1 mm, double-sided polishing, and then patterning and exposing using ultraviolet light combined with a mask (exposing with a laser of 310 nm wavelength for 30 s, and the aperture size of the mask is 80 µm) to obtain an exposed glass; Step 3: Gradient heat-treating the exposed glass (at 530 °C, holding for 2 h, then heating to 620 °C and holding for 2 h) to obtain a microcrystalline glass; Step 4: Etching the microcrystalline glass in a 10% hydrofluoric acid solution for 10 min to form through-holes with a diameter of 100 µm and a depth-to-diameter ratio of 10:1.

[0032] Figure 8 The optical profiler photograph of the through-holes in this embodiment is shown. It can be clearly seen from the picture that the etching boundary is neat and the hole wall is smooth, indicating that the etching process has high area selectivity and accuracy. In addition, the uncompletely etched area shows larger crystal grains, further verifying the stability of the microcrystalline structure formed by the PTR glass after ultraviolet light exposure and heat treatment. This result fully proves that the through-hole preparation method in the present invention has excellent etching effects and can achieve high-precision and high-quality microstructural processing.

[0033] In the description of the specification, the description referring to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0034] The above content is only an example and illustration of the present invention. Those skilled in the art of the present technology make various modifications or supplements or use similar methods to replace the specific embodiments described, as long as they do not deviate from the invention or exceed the scope defined by the claims of the present invention, they should fall within the protection scope of the present invention.

Claims

1. A method for preparing a high-precision glass through-hole based on PTR glass, characterized in that: It includes the following steps: Step 1: Subject the glass raw materials to high-temperature melting, casting, and annealing to obtain a PTR glass substrate; Step 2: Cut and double-side polish the PTR glass substrate, and then perform patterned exposure using ultraviolet light in combination with a mask to obtain an exposed glass; Step 3: Perform gradient heat treatment on the exposed glass to obtain a crystallized glass; Step 4: Etch the crystallized glass in a hydrofluoric acid solution to obtain a glass through-hole with a high aspect ratio.

2. The preparation method of a high-precision glass through hole based on PTR glass according to claim 1, characterized in that: The glass raw materials are composed of the following components: 50–70wt% SiO2, 7–15wt% Na2O, 1–4wt% KBr, 3–8wt% Al2O3, 5–15wt% NaF, 4–8wt% ZnO, 0.1–0.5wt% Sb2O3, 0.1-0.5wt% La2O3, 0.1-0.5wt% TiO2, 0.02–0.1wt% CeO2, 0.02–0.1wt% Ag2O.

3. The preparation method of a high-precision glass through-hole based on PTR glass according to claim 2, wherein: The total content of Na2O and NaF is 10-20wt%, and the mass ratio of CeO2 to Ag2O is (1-2):

1.

4. A method for preparing a high-precision glass through-hole based on PTR glass according to claim 1, characterized in that: The process parameters for the melting are: temperature 1400-1600°C, time 2-4h; the process parameters for the annealing are: temperature 400-600°C, time 1-4h.

5. A method for preparing a high-precision glass through-hole based on PTR glass according to claim 1, characterized in that: The process parameters of the patterned exposure are as follows: the wavelength of the laser is 300 - 320 nm, the output power is 1 - 10 W, the exposure time is 10 - 60 s, and the exposure energy density is 1 - 10 J / cm 2 .

6. The preparation method of a high-precision glass through hole based on PTR glass according to claim 1, characterized in that: The process parameters for the gradient heat treatment are: at 450-550°C, hold for 1-3h, and then raise the temperature to 550–700°C and hold for 1-3h.

7. The preparation method of a high-precision glass through-hole based on PTR glass according to claim 1, wherein: The concentration of the hydrofluoric acid solution is 5-20wt%; the etching time is 5-30min.

8. A method for preparing a high-precision glass through-hole based on PTR glass according to claim 1, characterized in that: The etching process is carried out under ultrasonic assistance, and the ultrasonic frequency is 20–100kHz.

9. The preparation method of a high-precision glass through-hole based on PTR glass according to claim 1, wherein: The aperture range of the through-hole is 30-100µm, and the aspect ratio range is (5-20):1.

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