Glass for through-hole glass substrate and preparation method thereof

Abstract

The invention discloses glass for a through-hole glass substrate and a preparation method of the glass, and belongs to the technical field of through-hole glass. Comprising the following steps: weighing raw materials according to a ratio, uniformly mixing, melting at 1550-1650 DEG C, homogenizing and clarifying, molding into a required shape, and annealing to finally obtain finished glass. Wherein the thermal expansion coefficient of the finished glass in the range of 50-300 DEG C is (4.0-5.0) * 10 <-6 > / DEG C, and the dielectric loss tangent value tan delta at the frequency of 0.8 GHz is less than 0.003. According to the invention, through a unique component ratio, two properties, namely a proper thermal expansion coefficient and extremely low dielectric loss, which are crucial to TGV application are successfully and perfectly combined together, so that the problem that an existing glass material is difficult to give consideration to the two properties is solved. And the preparation process belongs to a conventional technology, is easy to realize large-scale production, and has a good industrialization prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of through glass via (TGV) glass, and particularly relates to a glass for a through glass via glass substrate and a preparation method thereof. BACKGROUND

[0002] In the field of microelectronic packaging, with the rapid development of 5G / 6G communication and three-dimensional integration technology, the performance requirements for packaging substrate materials are increasingly stringent. Currently, three-dimensional packaging mainly uses organic substrates, but in large-size packaging above 12 inches, organic materials have shown obvious bottlenecks: the coefficient of thermal expansion (CTE) is seriously mismatched with silicon chips, leading to the accumulation of thermal stress, packaging warping, and thus increasing the risk of interface delamination, significantly reducing the reliability of devices.

[0003] In contrast, glass substrates, with their adjustable thermal expansion coefficient and low dielectric loss, are becoming a frontier direction to break through the bottleneck of three-dimensional integration technology. As the core basic material of through glass via (TGV) three-dimensional advanced packaging, the key performance of the substrate glass, such as dielectric loss and coefficient of thermal expansion, directly determines the quality of through hole / filling hole and the stability and long-term reliability of high-density laminated wiring, and thus has become a global research hotspot for advanced packaging glass materials.

[0004] However, not all glasses are suitable for high-end packaging scenarios. An ideal packaging substrate glass must meet two core indicators: (1) appropriate coefficient of thermal expansion: it needs to be well matched with silicon chips and metal materials used in subsequent processes to minimize thermal stress and avoid warping or cracking; (2) extremely low dielectric loss (tan delta): at high-frequency signal transmission (such as 5G / 6G frequency bands), it must maintain extremely low dielectric loss to reduce signal attenuation and ensure signal integrity.

[0005] Currently, commercially available low-expansion borosilicate glasses may meet the requirements in terms of coefficient of thermal expansion, but their dielectric loss is usually higher than 0.005, making them difficult to meet higher frequency applications; while some glasses with excellent dielectric performance, their coefficient of thermal expansion is often too high to match with silicon.

[0006] Therefore, developing a new packaging glass material with low dielectric loss and silicon-compatible coefficient of thermal expansion has become a key challenge to promote the development of the next generation of three-dimensional integrated packaging technology. SUMMARY

[0007] The purpose of the present application is to overcome the defects of the prior art and provide a glass for a through glass via glass substrate and a preparation method thereof.

[0008] The purpose of the present application can be achieved by the following technical solutions: A preparation method of glass for a through-hole glass substrate, comprising the following steps: S1: proportionally weighing each raw material and uniformly mixing to obtain a batch; S2: melting and homogenizing the batch at 1550-1650 DEG C to obtain a molten glass liquid; S3: forming the molten glass liquid and then performing annealing treatment to obtain a finished glass; The finished glass has a thermal expansion coefficient of (4.0-5.0) x 10 -6 / ℃ in the range of 50-300 DEG C, and a dielectric loss tangent tan delta of less than 0.003 at a frequency of 0.8 GHz.

[0009] More preferably, the raw material composition of the batch comprises, in terms of weight percentage: SiO2: 50-70%; B2O3: 0-8%; Al2O3: 10-20%; MgO: 0-10%; CaO: 0-10%; SrO: 0-10%; BaO: 0-10%; SnO2: 0.2%.

[0010] More preferably, the mass ratio of Al2O3 to MgO is (4-7):1.

[0011] In the scheme, the synergistic effect of Al2O3 and MgO reduces the dielectric loss while maintaining a suitable thermal expansion coefficient. Mg 2+ ions provided by MgO make it easier for Al2O3 to integrate into the network. The synergy of Al2O3 and MgO reduces the number of non-bridging oxygen in the glass, enhancing network integrity and thus significantly reducing dielectric loss. At the same time, the ionic radius of MgO is smaller, and it breaks the network to a lesser extent, so the increase in CTE is limited. Al2O3 itself can increase the rigidity of the glass, helping to maintain low thermal expansion.

[0012] More preferably, the mass ratio of CaO to BaO is (2-5):1; and the mass ratio of CaO to SrO is (2-5):1.

[0013] In the scheme, when alkaline earth metal oxides (CaO, SrO, BaO) act together, a "mixed alkaline earth effect" occurs. Due to the difference in ionic radius, they can more effectively fill the gaps in the glass network, reducing free volume and thus reducing thermal expansion coefficient and suppressing ion migration, reducing dielectric loss. At the same time, by adjusting the proportion, the CTE can be finely controlled: CaO has a smaller effect on increasing CTE, while SrO and BaO have a larger effect on increasing CTE, so using CaO as the main component with a small amount of BaO or SrO can balance the CTE.

[0014] More preferably, in step S2, the melting, homogenizing and fining treatment time is 2-8h.

[0015] More preferably, in step S3, the annealing treatment has the following process parameters: temperature 600-700℃, time 0.5-2h.

[0016] Compared with the prior art, the present application has the following advantages: (1) The present application successfully combines the two important properties for TGV application, i.e. suitable thermal expansion coefficient (4.0-5.0)×10 -6 / ℃ and extremely low dielectric loss (tanδ less than 0.003), by using unique component proportioning, which solves the problem that the existing glass materials are difficult to meet both requirements.

[0017] (2) The melting-molding-annealing process used in the present application is a conventional technology in glass industry, which is easy to realize large-scale production and has good industrialization prospect. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0019] The finished glass obtained in the embodiments 1-7 and the comparative examples 1-3 of the present application is prepared by using the following general preparation method, which comprises the following steps: S1: weighing each raw material according to the proportioning in Table 1 and mixing uniformly to obtain a batch; S2: melting the batch at the temperature shown in Table 1, homogenizing and fining to obtain a molten glass liquid; S3: forming the molten glass liquid into a desired shape, and then annealing treatment at 650℃ for 0.5h to eliminate internal stress to obtain a finished glass.

[0020] Table 1 Component SiO2 Al2O3 B2O3 MgO CaO SrO BaO SnO2 Melting temperature (°C) Example 1 67 12.8 1 3 8 4 4 0.2 1650 Example 2 62 18.8 1 3 8 4 3 0.2 1650 Example 3 62 17.8 2 3 8 4 3 0.2 1650 Example 4 62 18.8 0 3 8 4 4 0.2 1650 Example 5 62 16.8 2 3 8 4 4 0.2 1650 Example 6 59 17.8 4 3 8 4 4 0.2 1650 Example 7 55 17.8 8 3 8 4 4 0.2 1650 Comparative Example 1 59.8 10 10 5 5 5 5 0.2 1650 Comparative Example 2 63.6 12.8 1 6.4 8 4 4 0.2 1650 Comparative Example 3 56.8 24 1 3 5 5 5 0.2 1650 Comparative Example 4 68 12.8 1 3 5 5 5 0.2 1650 Comparative Example 5 61.8 18 1 3 12 2 2 0.2 1650 Test: The finished glass samples obtained in the embodiments and the comparative examples are subjected to performance test. The thermal expansion coefficient is determined by using a thermal mechanical analyzer, and the dielectric loss is determined by using a network analyzer combined with a coaxial resonant cavity method. The obtained results are shown in Table 2: Table 2 Item CTE x 10 -6 (300 °C) Dielectric loss @ 0.8GHz Example 1 4.23 0.0017 Example 2 4.14 0.0026 Example 3 4.02 0.0025 Example 4 4.58 0.0021 Example 5 4.37 0.0026 Example 6 4.30 0.0024 Example 7 4.69 0.0018 Comparative Example 1 5.03 0.0038 Comparative Example 2 4.97 0.0031 Comparative Example 3 4.53 0.0057 Comparative Example 4 4.72 0.0038 Comparative Example 5 4.11 0.0041 Conclusion: The thermal expansion coefficients of all the glasses of Examples 1-7 of the present application are successfully controlled in the range of 4.02-4.69 x 10 -6 / ℃, which is very close to the thermal expansion coefficient of silicon chip (about 4.1 x 10 -6 / ℃-4.5 x 10 -6 / ℃). At the same time, the dielectric loss tangent values of all the glasses at 0.8 GHz are lower than 0.003, with the lowest being 0.0017 (Example 1), achieving the perfect combination of low expansion and low dielectric loss.

[0021] In contrast, the performance of the comparative examples has significantly declined, which strongly proves the importance of the specific component ratio of the present application: The thermal expansion coefficient of Comparative Example 1 is 5.03 x 10 -6 / ℃, and the dielectric loss is 0.0038, which is higher than the threshold value of 0.003. The root cause lies in the unreasonable component design: on the one hand, the content of Al2O3 (10%) is too low, and it is not effectively matched with MgO, resulting in insufficient integrity of the glass network structure, which makes it difficult to effectively suppress the thermal expansion coefficient and dielectric loss; on the other hand, the amounts of various alkaline earth metal oxides (CaO, SrO, BaO) are balanced, and the "mixed alkaline earth effect" mainly using CaO cannot be used to optimize the performance.

[0022] The performance of Comparative Example 2 is also not ideal. The key problem lies in the unbalanced mass ratio of Al2O3 to MgO, which is far lower than the requirement of (4-7):1 of the present application. The breaking effect of excessive MgO on the glass network is enhanced, resulting in an increase in the thermal expansion coefficient; at the same time, the relative shortage of Al2O3 makes it difficult to fully play the role of enhancing network rigidity and reducing non-bridging oxygen to reduce dielectric loss.

[0023] The Al2O3 / MgO of Comparative Example 3 is 8:1, which is much higher than the requirement of (4-7):1 of the present application. Although the excessive Al2O3 makes the thermal expansion coefficient decrease, it also leads to an increase in the number of non-bridging oxygen, resulting in a great increase in dielectric loss.

[0024] The performance of Comparative Example 4 also fails to meet the requirements, and the proportion of alkaline earth metal oxides is imbalanced: the mass ratio of CaO to BaO and CaO to SrO is both 1:1, which is far from the optimized range of (2-5):1 of the present application. Less Ca with a smaller radius cannot effectively fill the network voids, resulting in poor control of the thermal expansion coefficient and high dielectric loss.

[0025] The mass ratio of CaO to BaO and CaO to SrO in Comparative Example 5 is 6:1, which is higher than the optimized range of (2-5):1 of the present application. Although the thermal expansion coefficient is well controlled, it also leads to a weakening of the "mixed alkaline earth effect", making it difficult to effectively inhibit ion migration and resulting in high dielectric loss.

[0026] In summary, the present application successfully solves the technical problem of balancing low thermal expansion coefficient and low dielectric loss in the prior art by using a specific component ratio.

[0027] In the description of the specification, the description of the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0028] The above is only an example and description of the present application, and those skilled in the art can make various modifications or supplements to the described specific embodiments or use similar ways to replace them, as long as they do not deviate from the invention or exceed the scope defined by the present claims, which shall be within the protection scope of the present application.

Claims

1. A method for preparing glass for through-hole glass substrates, characterized in that, Includes the following steps: S1: Weigh each raw material according to the proportion and mix them evenly to obtain the batch material; S2: Melt and homogenize the batch material at 1550-1650℃ to obtain molten glass. S3: Molten glass is shaped and then annealed to obtain finished glass; The coefficient of thermal expansion of the finished glass in the range of 50-300℃ is (4.0-5.0)×10⁻⁶. -6 / ℃, and the dielectric loss tangent tanδ at 0.8GHz is less than 0.

003.

2. The method for preparing glass for through-hole glass substrates according to claim 1, characterized in that, The raw material composition of the batching material, by weight percentage, includes: SiO2: 50-70%; B2O3: 0-8%; Al2O3: 10-20%; MgO: 0-10%; CaO: 0-10%; SrO: 0-10%; BaO: 0-10%; SnO2: 0.2%.

3. The method for preparing glass for through-hole glass substrates according to claim 2, characterized in that, The mass ratio of Al2O3 to MgO is (4-7):

1.

4. The method for preparing glass for through-hole glass substrates according to claim 2, characterized in that, The mass ratio of CaO to BaO is (2-5):1; the mass ratio of CaO to SrO is (2-5):

1.

5. The method for preparing glass for through-hole glass substrates according to claim 1, characterized in that, In step S2, the melting, homogenization and clarification process takes 2-8 hours.

6. A method for preparing glass for through-hole glass substrates according to claim 1, characterized in that, In step S3, the annealing process parameters are: temperature 600-700℃ and time 0.5-2h.

7. Finished glass obtained by the method for preparing glass for through-hole glass substrates according to any one of claims 1-6.