Glass metallization paste, method of making the same, glass vacuum sealing method, and glass article

Abstract

The application discloses a glass metallization paste, a preparation method thereof, a glass vacuum sealing method and a glass product, and relates to the technical field of vacuum glass sealing. The glass metallization paste comprises the following components in parts by weight: 75-85 parts of copper powder; 3-8 parts of glass powder; and 10-15 parts of an organic carrier. The surface of the copper powder is coated with an antioxidation layer. The antioxidation layer blocks oxygen during the process of heating the glass metallization paste to a peak temperature, and prevents the oxidation of the copper powder. The glass metallization paste has good printing suitability and sintering density, and provides a key material basis for realizing high-quality metallization in an air atmosphere.

Description

Technical Field

[0001] This application relates to the field of vacuum glass sealing technology, and in particular to a glass metallization slurry and its preparation method, a glass vacuum sealing method, and glass products. Background Technology

[0002] In the field of vacuum glass sealing, it is often necessary to seal the edges of two or more pieces of glass to form a sealed cavity. However, existing sealing technologies and materials have obvious limitations: the sealed body obtained by glass powder sintering is a brittle glass material with poor impact resistance, strict requirements for matching thermal expansion coefficients, and is prone to residual stress, resulting in limited sealing strength; although resin-based low-temperature curing slurries have low process temperatures, they rely on organic resin bonding, have poor heat resistance and weather resistance, and are prone to aging and decomposition after long-term use, leading to sealing failure, making it difficult to meet high reliability requirements; high-temperature sintering sealing with silver paste is expensive; other metallization methods such as magnetron sputtering and chemical plating require large equipment investment, have complex processes, and low film formation rates, making it difficult to achieve efficient thick film preparation for wide glass edges, resulting in poor cost-effectiveness. While copper is an ideal sealing material, it oxidizes readily at high temperatures, typically requiring sintering in a protective atmosphere such as nitrogen. This process involves complex equipment and high costs. Conventional copper pastes, when sintered in air at high temperatures, are prone to deep oxidation, forming a copper oxide layer that cannot be effectively removed by conventional acid pickling, thus failing to meet the requirements for welding and sealing. Therefore, there is an urgent need to develop a copper-based paste to achieve copper metallization of glass in an air atmosphere, laying the foundation for subsequent vacuum tin sealing. Summary of the Invention

[0003] The main purpose of this application is to propose a glass metallization paste and its preparation method, a glass vacuum sealing method, and glass products, aiming to solve the problem that existing copper-based pastes cannot achieve copper metallization of glass in an air atmosphere.

[0004] To achieve the above objectives, in a first aspect, this application provides a glass metallization paste, which comprises, by weight, the following components: Copper powder: 75-85 parts; Glass powder: 3-8 parts; Organic carrier: 10-15 parts; The copper powder is coated with an antioxidant layer, which blocks oxygen during the heating process to the peak temperature, thus preventing the copper powder from oxidizing.

[0005] In some embodiments, the copper powder is a compound of a first copper powder and a second copper powder, wherein the particle size of the first copper powder is 1~5μm and the particle size of the second copper powder is 100~500nm.

[0006] In some embodiments, the weight ratio of the first copper powder to the second copper powder is 60~80:20~40.

[0007] In some embodiments, the softening temperature of the glass powder is 480~600°C.

[0008] In some embodiments, the glass powder comprises the following components by weight: SiO2: 5~20 parts; B2O3: 15~35 parts; Bi2O3: 40~60 parts; ZnO: 5~15 parts; Na2O: 0~8 parts; Al2O3: 0~5 parts.

[0009] In some embodiments, the organic carrier includes at least two of ethyl cellulose, acrylic resin, terpineol, and butyl carbitol acetate.

[0010] Secondly, this application proposes a method for preparing a glass metallization slurry, comprising: The copper powder and the glass powder are mixed evenly. The mixed powder is mixed with an organic carrier and then ground and dispersed to obtain the glass metallization slurry, wherein the fineness of the glass metallization slurry is ≤10μm.

[0011] Thirdly, this application proposes a glass vacuum sealing method, the glass sealing method comprising: The glass metallization paste proposed in the first aspect of this application is applied to a glass substrate; The coated glass substrate is baked in air at 100-150°C for 10-40 minutes, then held in air at 650-750°C for 90-500 seconds, and then cooled to form a metallization layer. After surface treatment of the glass substrate to which the metallization layer is formed, soldering is performed. At least two of the soldered glass substrates are sealed together.

[0012] In some embodiments, the surface treatment includes mechanical polishing, weak acid cleaning, water washing, and drying. The cooling process has a cooling rate of 350~550℃ / min and a time of 1~2min.

[0013] Fourthly, this application provides a glass article comprising at least two glass substrates and a sealing layer located between two adjacent glass substrates, wherein the sealing layer is prepared using the glass vacuum sealing method proposed in the third aspect of this application.

[0014] The glass metallization paste proposed in this application, by limiting the contents of copper powder, glass powder and organic carrier to 75-85 parts, 3-8 parts and 10-15 parts respectively, and setting an anti-oxidation coating layer on the surface of copper powder, forms a paste formulation that matches the rapid sintering process. The resulting paste has good printability and sintering density. The anti-oxidation coating layer effectively blocks oxygen during rapid heating and prevents copper powder oxidation, providing a key material basis for achieving high-quality metallization in an air atmosphere.

[0015] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Detailed Implementation

[0016] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0017] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0018] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0019] In a first aspect, embodiments of this application provide a glass metallization slurry comprising, by weight, the following components: copper powder: 75-85 parts; glass powder: 3-8 parts; organic carrier: 10-15 parts. The copper powder surface is coated with an antioxidant layer. This antioxidant layer effectively blocks oxygen during rapid heating to the peak temperature, preventing oxidation of the copper powder. The antioxidant layer can be selected from one or more of organic coating layers and inorganic oxide coating layers, preferably an organic coating layer.

[0020] By limiting the contents of copper powder, glass powder, and organic carrier to 75-85 parts, 3-8 parts, and 10-15 parts respectively, and by applying an anti-oxidation coating layer to the surface of the copper powder, a basic slurry formulation matching the rapid sintering process was formed. The glass metallization slurry was fed into the furnace at a peak temperature of 650-750℃. Before the glass powder rapidly melts and coats the copper powder, the anti-oxidation layer provides oxidation protection for a short time. After the glass powder melts, it coats the copper powder, blocking air. At this point, the copper powder coating layer decomposes, cracks, or carbonizes at high temperature. Due to the small amount of coating layer, the impact of decomposition, cracking, or carbonization on sintering is negligible. The copper powder is encapsulated in the glass liquid phase and undergoes liquid-phase sintering with the glass liquid phase, thus providing a key material basis for subsequent high-quality metallization in an air atmosphere.

[0021] Furthermore, the complete replacement of precious metals with low-cost copper and the adoption of a lead-free glass system align with green manufacturing trends. This glass metallization paste enables high-quality glass metallization in conventional air sintering furnaces, with low equipment requirements, extremely short process cycles (minutes), and significantly superior production efficiency and cost-effectiveness compared to silver paste solutions.

[0022] In some embodiments, the copper powder is a compound of a first copper powder and a second copper powder, wherein the particle size of the first copper powder is 1~5μm and the particle size of the second copper powder is 100~500nm.

[0023] Micron-sized copper powder (first copper powder) serves as the framework to maintain the stability of the film structure, while nano-sized copper powder (second copper powder) drives rapid densification within a short holding time due to its high surface activity. The synergistic effect of these two components allows for the formation of a continuous and dense metallization layer within an extremely short sintering window of 90–500 seconds. Simultaneously, the anti-oxidation coating on the copper powder surface prevents oxidation during rapid heating to the peak temperature and does not hinder the metallization process during subsequent sintering. This fundamentally solves the core contradiction of air sintering, thus avoiding the problems of insufficient densification or severe oxidation associated with single-size copper powder sintering.

[0024] In some embodiments, the weight ratio of the first copper powder to the second copper powder is 60-80:20-40. Within this range, the skeletal support of the micron-sized copper powder and the active sintering effect of the nano-sized copper powder achieve an optimal balance, ensuring both the structural integrity of the sintered film and rapid densification. Beyond this range, the densification effect or oxidation resistance significantly decreases.

[0025] In some embodiments, the softening temperature of the glass powder is 480~600°C.

[0026] In some embodiments, the glass powder comprises the following components by weight: SiO2: 5-20 parts; B2O3: 15-35 parts; Bi2O3: 40-60 parts; ZnO: 5-15 parts; Na2O: 0-8 parts; Al2O3: 0-5 parts.

[0027] The softening point of the lead-free glass powder is strictly limited to a narrow window of 480~600℃, and its content is controlled within a critical range of 3%~8%. This design ensures that the glass powder can fully melt and wet the copper powder within a short period of heat preservation before the copper powder coating layer fails at high temperatures. It also physically blocks the contact between the copper powder and air, creating a "localized oxygen-free sintering environment in an air atmosphere." The specific lead-free formulation (based on Bi2O3 and other similar systems) meets environmental regulations while achieving precise matching of the coefficient of thermal expansion (CTE) with the soda-lime glass substrate (CTE difference ≤ ±10×10). -7 / ℃), eliminating sintering thermal stress.

[0028] In some embodiments, the organic carrier includes at least two of ethyl cellulose, acrylic resin, terpineol, and butyl carbitol acetate.

[0029] This application also proposes a method for preparing the glass metallization paste as described above, comprising: S101. Mix the copper powder and the glass powder evenly; S102. The mixed powder is mixed with an organic carrier and then ground and dispersed to obtain the glass metallization slurry, wherein the fineness of the glass metallization slurry is ≤10μm.

[0030] By pre-mixing copper powder and glass powder evenly, then mixing with an organic carrier and grinding and dispersing to a fineness of ≤10μm, uniform dispersion of each component in the slurry is ensured, avoiding sintering defects caused by particle agglomeration. This method is simple, controllable, and can stably prepare glass metallization slurries that meet the requirements of rapid sintering processes.

[0031] This application also provides a glass vacuum sealing method, including: S201. Apply the glass metallization paste as described above to the glass substrate; S202. The coated glass substrate is baked in air at 100-150°C for 10-40 minutes, then kept at 650-750°C in air for 90-500 seconds, and then cooled to form a metallization layer. S203. After surface treatment of the glass substrate on which the metallization layer is formed, soldering is performed. S204. Seal at least two of the soldered glass substrates together.

[0032] In S202, the holding temperature can be 650℃, 660℃, 670℃, 680℃, 690℃, 700℃, 710℃, 720℃, 730℃, 740℃, or 750℃, etc. The holding time can be 90s, 150s, 200s, 250s, 300s, 350s, 400s, 450s, or 500s, etc. The cooling time can be 1 min, 1.5 min, or 2 min, etc.

[0033] In some embodiments, the cooling process takes 1 to 2 minutes and the cooling rate is 350 to 550°C / min. For example, the cooling time can be 1 minute, 1.5 minutes, or 2 minutes, etc. The cooling rate can be 350°C / min, 400°C / min, 450°C / min, 500°C / min, or 550°C / min, etc.

[0034] The glass vacuum sealing method provided in this application embodiment is deeply coupled with the above-mentioned glass metallization paste formulation: the copper powder is exposed to high temperature air for a large time by rapidly feeding into the furnace and short-term heat preservation, and the oxidation reaction is quickly terminated by rapid cooling after exiting the furnace; the subsequent soldering and vacuum sealing steps ensure the high strength and high airtightness of the sealing layer.

[0035] In other words, the glass metallization slurry described above is not a universal formula. Each component parameter (particle size, coating, softening point, content) is designed specifically for the disruptive process of "entering the furnace at peak temperature (650~750℃), short-term holding (90~500s), and rapid cooling upon exiting the furnace." The synergistic effect of the two produces a "1+1>2" result: the rapid sintering process ensures the feasibility of sintering in an air atmosphere, while the specially designed glass metallization slurry ensures the formation of a dense, high-strength metallization layer with no inner oxidation and a controllable surface oxide layer (which can be removed by the matching post-treatment process) within an extremely short sintering time window.

[0036] This application also provides a glass article. The glass article includes at least two glass substrates and a sealing layer located between two adjacent glass substrates. The sealing layer is prepared using the glass vacuum sealing method described above.

[0037] The following specific examples provide further details.

[0038] Examples 1-9 (1) Preparation of organic carriers Four parts by weight of ethyl cellulose and two parts by weight of acrylic resin (both solids content) were added to 94 parts by weight of a mixed solvent. The mixed solvent consisted of 70 wt% terpineol and 30 wt% butyl carbitol acetate.

[0039] (2) Preparation of glass powder Weigh each component according to Table 1 and mix them thoroughly. Place the mixture in a corundum crucible and put it into a high-temperature furnace. Melt, clarify, and homogenize at 1400℃ for about 1-2 hours. Pour the molten glass into deionized water and cool rapidly to obtain glass slag. After drying the glass slag, place it in a zirconia ball mill jar and add ethanol for wet ball milling. After ball milling, dry and sieve to obtain three types of glass powder (1# glass powder, 2# glass powder, and 3# glass powder) with a particle size distribution D50 of 2-5 μm.

[0040] Table 1. Glass Powder Composition

[0041] (3) Preparation of glass metallization slurry Accurately weigh each component according to the proportions in Table 2. Mix the copper powder and glass powder evenly in a container. Add approximately 2 / 3 of the organic carrier to the premixed powder and stir with a planetary mixer at low speed (200-500 rpm) for 10-15 minutes to form a homogeneous paste. Transfer the paste to a three-roll mill for grinding. Adjust the roller gap and grind repeatedly 3-5 times until the fineness of the paste is less than 10 μm as measured by a scraper fineness gauge. Add the remaining organic carrier and stir evenly at low speed. Adjust the final paste viscosity to a range suitable for screen printing (typically, at 25°C, the Brookfield viscosity is between 25,000 and 50,000 cP). Filter the paste through a 200-300 mesh sieve to remove any large particles. Seal and allow to stand (aging) for at least 24 hours to stabilize the rheological properties of the paste.

[0042] Table 2. Glass Metallization Slurry Composition Table

[0043] Comparative Examples 1-7 (1) Preparation of organic carriers Four parts by weight of ethyl cellulose and two parts by weight of acrylic resin (both solids content) were added to 94 parts by weight of a mixed solvent. The mixed solvent consisted of 70 wt% terpineol and 30 wt% butyl carbitol acetate.

[0044] (2) Preparation of glass powder Weigh each component according to Table 3 and mix them evenly. Place the mixture in a corundum crucible and put it into a high-temperature furnace. Melt, clarify, and homogenize at 1400℃ for about 1-2 hours. Pour the molten glass into deionized water and cool rapidly to obtain glass slag. After drying the glass slag, place it in a zirconia ball mill jar and add ethanol for wet ball milling. After ball milling, dry and sieve to obtain two types of glass powder (4# glass powder and 5# glass powder) with a particle size distribution D50 of 2-5 μm.

[0045] Table 3. Glass Powder Composition

[0046] (3) Preparation of glass metallization slurry Accurately weigh each component according to the proportions in Table 4. Mix the copper powder and glass powder evenly in a container. Add approximately 2 / 3 of the organic carrier to the premixed powder and stir with a planetary mixer at low speed (200-500 rpm) for 10-15 minutes to form a homogeneous paste. Transfer the paste to a three-roll mill for grinding. Adjust the roller gap and grind repeatedly 3-5 times until the fineness of the paste is less than 10 μm as measured by a scraper fineness gauge. Add the remaining organic carrier and stir evenly at low speed. Adjust the final paste viscosity to a range suitable for screen printing (typically, at 25°C, the Brookfield viscosity is between 25,000 and 50,000 cP). Filter the paste through a 200-300 mesh sieve to remove any large particles. Seal and allow to stand (aging) for at least 24 hours to stabilize the rheological properties of the paste.

[0047] Table 4. Glass Metallization Slurry Composition Table

[0048] The copper pastes prepared in Examples 1-9 and Comparative Examples 1-7 were screen printed (100-200 mesh screen) onto a clean and dry soda-lime glass substrate (100 mm × 100 mm × 5 mm) with lines 5 mm wide and about 50-100 μm thick. The printed substrates were dried in a circulating hot air oven (or chain furnace) at 100-150℃ for 10-40 minutes in an air atmosphere to remove most of the organic solvents. They were then placed in a sintering furnace preheated to the target temperature and held for the specified time (as shown in Tables 2 and 5). Afterward, they were quickly removed and placed on a strong air cooling platform to cool the samples to below room temperature within 2 minutes. The quality, shear strength, and helium leakage rate of the metallized sealing layer formed after cooling were tested. The film quality, shear strength (referring to national standard GB / T34338-2017), and helium leakage rate (referring to national standard GB / T 36259-2018) were tested using the specified methods, and the results are shown in Table 5.

[0049] Table 5. Performance Test of Metallized Sealing Edges

[0050] The following conclusions can be drawn from Table 5: (1) Based on the results of Examples 1 to 9, it can be seen that under the synergistic effect of the specific ratio of the glass metallization paste proposed in the embodiments of this application and the glass vacuum sealing method proposed in the embodiments of this application, a dense, low-oxidation, and high-strength metallization layer can be obtained, which fully meets the requirements of subsequent vacuum tin sealing.

[0051] (2) Combining Comparative Example 1 and Comparative Example 2, it can be seen that when the glass metallization paste does not contain the second copper powder (nano copper powder) or only contains the second copper powder (nano copper powder), the final metallization layer will fail.

[0052] (3) Combining Comparative Examples 6 and 7, it can be seen that if the rapid sintering process proposed in the embodiments of this application is deviated from (such as the traditional process used in Comparative Example 6, or the heat preservation time in Comparative Example 7 is too short), even if the same slurry is used, qualified products cannot be obtained.

[0053] In summary, the glass metallization slurry proposed in this application, combined with the glass vacuum sealing method proposed in this application, successfully achieved high-quality copper sintering in a normal air atmosphere, which was traditionally considered impossible. The metallized layer is dense, weldable, and exhibits excellent sealing strength (>20 MPa) and airtightness (<1×10⁻⁶). -12 The Pa·m³ / s) levels reach or even exceed those of silver paste sealing, while also possessing the significant advantages of low cost and lead-free environmental friendliness.

[0054] The above description is merely an exemplary embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made using the content of this application's specification under the technical concept of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A glass metallization paste, characterized in that, The glass metallization slurry comprises the following components by weight: Copper powder: 75-85 parts; Glass powder: 3-8 parts; Organic carrier: 10-15 parts; The copper powder is coated with an anti-oxidation layer, which blocks oxygen during the process of heating the glass metallization slurry to the peak temperature, thus preventing the copper powder from oxidizing.

2. The glass metallization paste as described in claim 1, characterized in that, The copper powder is composed of a first copper powder and a second copper powder, wherein the particle size of the first copper powder is 1~5μm and the particle size of the second copper powder is 100~500nm.

3. The glass metallization paste as described in claim 2, characterized in that, The weight ratio of the first copper powder to the second copper powder is 60~80:20~40.

4. The glass metallization paste as described in claim 1, characterized in that, The softening temperature of the glass powder is 480~600℃.

5. The glass metallization paste as described in claim 1, characterized in that, The glass powder, by weight, comprises the following components: SiO2: 5~20 parts; B2O3: 15~35 parts; Bi2O3: 40~60 parts; ZnO: 5~15 parts; Na2O: 0~8 parts; Al2O3: 0~5 parts.

6. The glass metallization paste as described in claim 1, characterized in that, The organic carrier includes at least two of ethyl cellulose, acrylic resin, terpineol, and butyl carbitol acetate.

7. A method for preparing the glass metallization slurry according to any one of claims 1 to 6, characterized in that, include: The copper powder and the glass powder are mixed evenly. The mixed powder is mixed with an organic carrier and then ground and dispersed to obtain the glass metallization slurry, wherein the fineness of the glass metallization slurry is ≤10μm.

8. A glass vacuum sealing method, characterized in that, The glass sealing method includes: The glass metallization paste as described in any one of claims 1 to 6 is applied to a glass substrate; The coated glass substrate is baked in air at 100-150°C for 10-40 minutes, then held in air at 650-750°C for 90-500 seconds, and then cooled to form a metallization layer. After surface treatment of the glass substrate to which the metallization layer is formed, soldering is performed. At least two of the soldered glass substrates are sealed together.

9. The glass vacuum sealing method as described in claim 8, characterized in that, The surface treatment includes mechanical polishing, weak acid cleaning, water washing and drying. The cooling process has a cooling rate of 350~550℃ / min and a time of 1~2min.

10. A glass article, characterized in that, It includes at least two glass substrates and a sealing layer located between two adjacent glass substrates, the sealing layer being prepared using the glass vacuum sealing method as described in claim 8 or 9.

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