Aluminum borosilicate glass with low dielectric constant and low dielectric loss as well as preparation method and application of aluminum borosilicate glass

Abstract

The invention relates to aluminum borosilicate glass with low dielectric constant and low dielectric loss and a preparation method and application thereof, and relates to the field of aluminum borosilicate glass manufacturing, the aluminum borosilicate glass comprises the following main components by molar percentage: 60%-85% of SiO2, 0-10% of Al2O3, 2%-30% of B2O3, 0-20% of alkaline earth oxide, 0-10% of alkali metal oxide, 0-10% of ZnO, 0-1% of P2O5 and 0-2% of TiO2 and / or ZrO2; during preparation, the raw materials are melted, clarified and homogenized according to the corresponding dosage, and then are annealed for 3-8 hours at the temperature of 600-650 DEG C. The obtained aluminum borosilicate glass can reduce transmission loss during high-frequency signal transmission, has dielectric constant stability which does not exceed + / -0.5 change under a 1-30 GHz signal test, and can be applied to preparation of integrated antennas, electronic packaging and micro electro mechanical system packaging.

Description

Technical Field

[0001] The present invention relates to the field of aluminoborosilicate glass manufacturing, and in particular to aluminoborosilicate glass with low dielectric constant and low dielectric loss, and a preparation method and application thereof. Background Art

[0002] The continued development of technologies like 5G, IoT, and artificial intelligence (AI) is placing higher demands on data transmission speed and stability. For example, the frequency of signal transmission and reception has increased from approximately 1 GHz to 10 GHz, and in some cases, even to 100 GHz. As signal frequencies continue to increase, the dielectric properties of the materials involved become increasingly important. Therefore, reducing signal transmission losses requires lowering the dielectric constant (Dk) and dielectric loss (Df) of the materials used.

[0003] Currently, although materials such as high-purity fused silica, sapphire, alumina, and silicon dioxide exhibit low dielectric loss at frequencies above 10 GHz, these materials have high forming temperatures and are difficult to manufacture. Aluminoborosilicate glass, with its high transmittance and excellent electrical properties, meets the challenges of high-frequency signal transmission from 1 to 30 GHz and even higher. Therefore, aluminoborosilicate glass is evolving from a traditional industrial material into a carrier for interactive interfaces and data flows in the intelligent era.

[0004] Among glasses, low dielectric constant is currently the main one. For example, the invention patent with application number 200710053979.9 and titled “Low Dielectric Constant Glass” has the following composition and weight percentage: SiO2 48~58%, Al2O3 10~20%, B2O3 20~30%, TiO2 0~5%, CaO 0~5%, MgO 0~5%, Na2O+K2O≤0.3%, F -10.01%~1%, V2O50.01%~0.5%, CeO20~1.5%. At room temperature, the dielectric constant at a frequency of only 1MHz is 4.1~5.2, but the glass cannot meet the requirements of low dielectric loss and low dielectric constant under high frequency conditions. In addition, the invention patent with application number 200710053979.9 and titled "A low dielectric constant glass and strengthened glass that can be used for chemical strengthening" has a composition and weight percentage of 71-75 mol% SiO2, 10-16 mol% Al2O3, 1-6 mol% Na2O, 4.5-8 mol%, SiO2+Al2O3 content greater than or equal to 80 mol%, Na2O+Li2O content between 9-12 mol%, P2O5+B2O3 content of 1-5 mol%, MgO content of 3.7-7.5 mol%, SnO2 content of 0.1-2 mol%, ZrO2 content of 0-5 mol%, TiO2 content of 0-5 mol%; and also contains no more than 2.5 mol% P2O5, after chemical strengthening, has a dielectric constant of 4.8 to 6.5 at room temperature and a frequency of 20 GHz. However, this glass does not meet the requirements for low dielectric loss and dielectric constant stability. Therefore, how to provide aluminoborosilicate glass with low dielectric constant, low dielectric loss, and good dielectric constant stability has become a pressing technical challenge. Summary of the Invention

[0005] In response to the problems existing in the prior art, the present invention provides an aluminum borosilicate glass with low dielectric constant and low dielectric loss, as well as a preparation method and application, to solve the problem of how to provide aluminum borosilicate glass with low dielectric constant, low dielectric loss and good stability, reducing the transmission loss of high-frequency signals when transmitting in aluminum borosilicate glass, and having a dielectric constant stability of no more than ±0.5 under 1~30GHz signal testing.

[0006] The present invention is achieved through the following technical solutions: Aluminoborosilicate glass with low dielectric constant and low dielectric loss, comprising a main component and a clarifier, wherein the main component comprises the following raw materials in the following amounts by molar percentage: 60%~85% SiO2, 0~10% Al2O3, 2%~30% B2O3, 0~20% RO, 0~10% R2O, 0~10% ZnO, 0~1% P2O5 and 0~2% TiO2 and / or ZrO2; The RO is an alkaline earth oxide, and R2O is an alkali metal oxide.

[0007] A further improvement of the present invention is: The alkaline earth oxide is one or more of MgO, CaO, BaO and SrO, and the alkali metal oxide is one or more of Li2O, Na2O and K2O.

[0008] The clarifier is one or more of NaCl, CeO2, SnO2, fluoride and Sb2O3, the clarifier accounts for 0-2% of the mass of the main component, and the fluoride is CaF2 or MgF2.

[0009] The SiO2, Al2O3 and B2O3 satisfy the following relationship: 0.03≤B2O3 / (Al2O3+SiO2)≤0.47.

[0010] The SiO2, Al2O3, B2O3, R2O and RO satisfy the following relationship: 0≤R2O / (Al2O3+SiO2+B2O3+RO)≤0.12.

[0011] When the alkali metal oxides are Li2O, Na2O and K2O, Li2O, Na2O and K2O satisfy the following relationship: The 0≤(1.4Li2O+1.6K2O) / 1.76Na2O≤14.32.

[0012] A method for preparing aluminoborosilicate glass with low dielectric constant and low dielectric loss comprises melting, clarifying and homogenizing the raw materials according to corresponding amounts, and then annealing at 600°C to 650°C for 3h to 8h to obtain aluminoborosilicate glass with low dielectric constant and low dielectric loss.

[0013] Application of aluminoborosilicate glass with low dielectric constant and low dielectric loss in the preparation of integrated antennas, electronic packaging and micro-electromechanical system packaging.

[0014] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention discloses an aluminoborosilicate glass with low dielectric constant and low dielectric loss. SiO2 serves as a glass network former, and [SiO4] tetrahedrons form a glass network skeleton, which can improve the mechanical strength and chemical stability of the glass. A content of 60% to 85% can reduce the dielectric constant and dielectric loss of the glass. If the content is too low, the glass forming performance, chemical stability, and dielectric properties of the glass deteriorate, and even glass cannot be formed. If the content is too high, the melting temperature of the glass is easily increased, and melting and clarification become difficult. B2O3 serves as a glass network former, and [BO3] triangles and [BO4] tetrahedrons are used as structural units. Together with [SiO4] tetrahedrons, the glass network skeleton can improve the thermal stability and acid and alkali resistance of the glass, and can also reduce the glass polarization, dielectric constant, and dielectric loss. It also has a fluxing effect, accelerating the dissolution and clarification of the glass. When B2O3 exceeds 30%, the increased [BO3] trigons increase the glass's expansion coefficient, leading to boron anomaly. Al2O3 participates in the glass network, reducing the glass's crystallization tendency and improving its chemical and thermal stability, mechanical strength, and hardness. However, excessive content increases glass melting difficulty. Furthermore, the larger space in the [AlO4] network structure compared to [SiO4] facilitates ion migration and easily forms oxygen vacancies, hindering dielectric properties. Therefore, a content of 0-10% can reduce the dielectric constant and dielectric loss. A RO content above 10% disrupts the glass network structure, reducing strength and chemical stability, while also deteriorating dielectric properties. Alkaline earth oxides not only aid glass melting but also suppress the mobility of alkali metal ions within the glass, contributing to a reduction in dielectric constant and dielectric loss. A RO content exceeding 20% disrupts the glass network structure, reducing strength and chemical stability, while increasing dielectric constant and dielectric loss. TiO2 and ZrO2 exist as network intermediates. Due to their strong field strength, they have a good suppressive effect on ion migration, which can reduce the dielectric loss of glass and improve the surface strength and scratch resistance of glass. However, a total content higher than 2% will cause glass phase separation and make the glass difficult to dissolve. ZnO can form a tetrahedral glass network. Due to the small radius of zinc ions, the tetrahedral structure formed will be very compact. At the same time, Zn +4 Valence has a certain suppressive effect on the migration of alkali metals in glass. By controlling its concentration to 0-10%, it can help reduce the dielectric constant and dielectric loss. P2O5 forms [PO4] and participates in the network structure. A content above 1% can reduce the chemical stability of the glass. Clarifiers can reduce glass bubbles and increase the light transmittance of the glass. These components work together to ultimately form aluminoborosilicate glass with low dielectric constant and low dielectric loss, reducing the transmission loss of high-frequency signals in aluminoborosilicate glass. Under 1-30 GHz signal testing, the dielectric constant stability does not exceed ±0.5. DETAILED DESCRIPTION

[0015] For ease of understanding of the present invention, the present invention will be described more fully below with reference to relevant embodiments. However, it will be apparent to those skilled in the art that, after benefiting from this specification, the present invention may be implemented in other embodiments than those described in detail herein.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. The terms used in the specification of the present invention herein are only for describing specific embodiments and are not intended to limit the present invention.

[0017] In the present invention, when a numerical range is involved, unless otherwise specified, the selection of all points within the numerical range is deemed to be continuous and include the two vertices of the numerical range, namely the minimum value and the maximum value.

[0018] In this disclosure, the terms "dielectric constant (Dk)" and "relative permittivity (εr)" are used interchangeably and are defined as the ratio of the absolute permittivity (ε) to the permittivity of a vacuum (ε0). Glass with a lower permittivity facilitates faster signal propagation and reduces capacitive coupling.

[0019] In this disclosure, the terms "dielectric loss," "loss tangent," and "dielectric loss tangent" are used interchangeably. Loss tangent is defined as the ratio of the imaginary to real parts of the complex dielectric constant. It represents the loss of energy in the glass of this disclosure, as a dielectric material, due to polarization or conversion of absorbed energy into heat when exposed to a frequency field. Lower dielectric loss indicates less energy lost during signal transmission, making the dielectric material more efficient.

[0020] In the context of the present invention, the term "dielectric constant stability" refers to the absolute difference between the maximum and minimum values of the dielectric constant in the test range of 1 GHz to 30 GHz, which indicates the dielectric stability of the sample at different frequencies.

[0021] In the context of the present invention, the term "coefficient of thermal expansion CTE" refers to a key parameter of the glass's dimensional characteristics as a function of temperature, and is typically expressed as 1 / °C.

[0022] The present invention provides an aluminoborosilicate glass having low dielectric constant and low dielectric loss properties, wherein the glass comprises, in terms of molar percentage: SiO2 60% to 85%; Al2O 30% to 10%; B2O3 2% to 30%; RO 0% to 20%; R2O 0% to 10%; ZnO 0% to 10%; 0% to 1% P2O5; RO (alkaline earth oxide) is selected from one or more of MgO, CaO, BaO and SrO; R2O (alkali metal oxide) is selected from one or more of Li2O, Na2O and K2O; In some embodiments, the glass further comprises TiO2 and / or ZrO2 in a molar ratio of 0% to 2%; At least one clarifier is additionally added in an amount not exceeding 2% of the total weight of the above components, the clarifier including but not limited to one or more of NaCl, CeO2, SnO2, fluoride, and Sb2O3; the fluoride clarifier can be introduced by CaF2 or MgF2 to reduce glass bubbles and improve glass transmittance; In some embodiments, the material ratio of the glass satisfies: 0.03≤B2O3 / (Al2O3+SiO2)≤0.47. In order to facilitate listing in the embodiments later and save space, B2O3 / (Al2O3+Si2O3) is set to A; In some embodiments, the material ratio of the glass satisfies: 0≤(Li2O+Na2O+K2O) / (Al2O3+SiO2+B2O3+MgO+CaO+BaO+SrO)≤0.12. In order to facilitate listing in the embodiments later and save space, (Li2O+Na2O+K2O) / (Al2O3+SiO2+B2O3+MgO+CaO+BaO+SrO) is set to B; In some embodiments, the material ratio of the glass satisfies: 0≤(1.4Li2O+1.6K2O) / 1.76Na2O≤14.32. To facilitate listing in the embodiments later and to save space, (1.4Li2O+1.6K2O) / 1.76Na2O is set to C. The glass of the present invention contains SiO2, which acts as a glass network former, forming a glass network skeleton with [SiO4] tetrahedrons, which can improve the mechanical strength and chemical stability of the glass. To ensure that the glass has good dielectric properties, the SiO2 content is generally above 70 mol%. However, in order to improve the glass melt fluidity, it is necessary to introduce or increase oxides with low additivity coefficients such as Al2O3 and B2O3. When the total content of each component remains unchanged, it is necessary to reduce the SiO2 content. However, if the SiO2 content is too low, the glass forming performance deteriorates, the chemical stability deteriorates, and the dielectric properties deteriorate, and even glass cannot be formed. Therefore, the SiO2 content is preferably 60 mol% to 85 mol% to reduce the dielectric constant and dielectric loss of the glass. If the SiO2 content is less than 60%, not only will the mechanical strength and chemical stability of the glass decrease, but the dielectric constant and dielectric loss will also increase. If the SiO2 content is higher than 85%, it is easy to cause the melting temperature of the glass to increase, and melting and clarification will become difficult.

[0023] B2O3, a glass network former, uses [BO3] triangles and [BO4] tetrahedra as structural units. Together with [SiO4] tetrahedra, it forms the glass network skeleton, improving the thermal stability and acid and alkali resistance of glass. It also reduces the polarization rate, dielectric constant, and dielectric loss of glass. It also acts as a flux, accelerating the dissolution and clarification of glass. When the B2O3 content exceeds 30%, the increase in [BO3] triangles increases the glass's expansion coefficient, leading to boron anomaly.

[0024] When Al2O3 forms a glass network, it can reduce the glass's crystallization tendency and improve its chemical stability, thermal stability, mechanical strength, and hardness. However, excessive Al2O3 content increases the difficulty of glass melting. Furthermore, since the [AlO4] network structure has a larger spatial space than [SiO4], it facilitates ion migration and easily forms oxygen vacancies, which is detrimental to improving dielectric properties. Therefore, setting the Al2O3 content between 0 mol% and 10 mol% can reduce the dielectric constant and dielectric loss. Furthermore, since the [AlO4] network structure has a larger spatial space than [SiO4], it facilitates ion migration and easily forms oxygen vacancies, which is beneficial for subsequent processing.

[0025] The glass of the present invention contains RO (MgO, CaO, SrO, and BaO). RO, as a network-external oxide, not only facilitates glass melting but also suppresses the migration of alkali metal ions within the glass, thereby helping to reduce the dielectric constant and dielectric loss. If the RO content in the glass exceeds 20%, the glass network structure will be destroyed, resulting in reduced strength and chemical stability, and an increase in the dielectric constant and dielectric loss.

[0026] The glass of the present invention contains R2O (Li2O, Na2O, and K2O) as a network oxide. This facilitates glass melting and introduces various alkali metal oxides, enhancing the mixed alkali effect. If the R2O content in the glass exceeds 10%, the glass network structure will be disrupted, reducing the glass's strength and chemical stability, and deteriorating its dielectric properties.

[0027] The present invention contains TiO2 and ZrO2, which exist as network intermediates. Due to their strong field strength, they have a good suppressing effect on ion migration, which can reduce the dielectric loss of the glass and also improve the surface strength and scratch resistance of the glass. However, a content higher than 2% will cause phase separation of the glass and make the glass difficult to dissolve.

[0028] The present invention contains ZnO, which can form a tetrahedral glass network. Since the radius of zinc ions is small, the tetrahedral structure formed is very compact. +4It has a certain suppressive effect on the migration of alkali metals in glass. By controlling its concentration to 0%~10%, it is beneficial to reduce the dielectric constant and dielectric loss.

[0029] The present invention contains P2O5, which can form [PO4] to participate in the network structure. A content higher than 1% will reduce the chemical stability of the glass.

[0030] In the present application, the ratio of B2O3 / (Al2O3+SiO2) is controlled to avoid excessive melting temperature and viscosity, and is beneficial to improving the thermal shock resistance of the glass.

[0031] Controlling the ratio of (Li2O+Na2O+K2O) / (Al2O3+SiO2+B2O3+MgO+CaO+BaO+SrO) is primarily concerned with controlling alkali migration in the glass, i.e., the ability of the glass to release alkali on its surface or the mobility of the alkali within the glass substrate itself. In particular, a high alkali ratio will lead to increased dielectric loss; therefore, the alkali content is limited.

[0032] Na2O is an important component for anodic bonding between glass and wafer in the later chip packaging process. + Low field strength facilitates laser-induced modification of the glass during later processing. Controlling the (1.4Li2O + 1.6K2O) / 1.76Na2O ratio in this application is primarily to ensure smooth anodic bonding of the glass to the wafer during later processing. Adjusting this ratio optimizes the ion migration characteristics of the glass, thereby promoting ion exchange at the bonding interface and electric field-driven bonding reactions, ensuring the stability and reliability of the bonding process.

[0033] During the subsequent laser processing, zinc has multiple valence states, which makes it easy to achieve very good etching selectivity. If its content exceeds 10%, it will cause glass phase separation.

[0034] The preparation method of the aluminoborosilicate glass with low dielectric constant and low dielectric loss properties of the present invention is as follows: The raw materials were weighed accurately according to the formula ratio, mixed for 60 minutes using a V-type mixer, and a mixed powder was obtained after uniform mixing. The mixed powder was added to a platinum crucible and melted at a high temperature of 1600-1650°C. After that, clarification and homogenization were completed at the same temperature for a total of 8-12 hours. At the same time, a platinum stirring rod was used to deeply stir the molten glass for 5 hours to help discharge bubbles in the glass.

[0035] The molten glass is then transferred to a casting mold and annealed at 600°C to 650°C for 3 to 8 hours before being cooled to room temperature to produce a glass product. Those skilled in the art will appreciate that during the melting process, various components may volatilize to varying degrees, potentially resulting in certain compositional differences between the original mixed powder and the final glass product. However, this is unavoidable and can be ignored.

[0036] The present invention provides the various formulas and proportions of Examples 1 to 27 and Comparative Examples 1 to 4, as well as the corresponding dielectric loss, dielectric constant, thermal expansion coefficient and dielectric constant stability. The melting temperature is 1650°C, the total time is 10 hours, and then annealing is performed at 630°C for 6 hours.

[0037] Table 1 Data related to Examples 1 to 9

[0038] Table 2 Data related to Examples 10 to 16

[0039] Table 3 Data related to Examples 17 to 23

[0040] Table 4 Data related to Examples 24 to 27 and Comparative Examples 1 to 4

[0041] As can be seen from Tables 1 to 4, the present invention provides a low dielectric constant and low dielectric loss aluminoborosilicate glass with a dielectric loss of 0.0041 to 0.005 and a dielectric constant of 4.34 to 6.89 (both measured at 10 GHz), and a dielectric constant stability of no more than ±0.5 under 1 to 30 GHz signal testing. In addition, the coefficient of thermal expansion (CTE) is 3.22 to 4.47 × 10-6 ° C. -1 , high dimensional stability, not easy to crack or deform due to thermal expansion and contraction.

[0042] The glass described in the present invention can be applied to various electronic devices, mainly to the preparation of integrated antennas, and is used in the fields of electronic packaging and micro-electromechanical system packaging, including but not limited to electronic chip adapter boards, interposers, support carriers, fan-out packaging, and antenna packaging integrated core-shell lens structures.

Claims

1. Aluminoborosilicate glass with low dielectric constant and low dielectric loss, characterized in that: The aluminoborosilicate glass comprises a main component and a clarifier. The main component comprises the following raw materials in molar percentage: 60%~85% SiO2, 0~10% Al2O3, 2%~30% B2O3, 0~20% RO, 0~10% R2O, 0~10% ZnO, 0~1% P2O5 and 0~2% TiO2 and / or ZrO2; The RO is an alkaline earth oxide, and R2O is an alkali metal oxide.

2. Aluminoborosilicate glass with low dielectric constant and low dielectric loss according to claim 1, characterized in that: The alkaline earth oxide is one or more of MgO, CaO, BaO and SrO.

3. Aluminoborosilicate glass with low dielectric constant and low dielectric loss according to claim 1, characterized in that: The alkali metal oxide is one or more of Li2O, Na2O and K2O.

4. Aluminoborosilicate glass with low dielectric constant and low dielectric loss according to claim 1, characterized in that: The clarifier is one or more of NaCl, CeO2, SnO2, fluoride and Sb2O3, and the mass of the clarifier does not exceed 2% of the mass of the main component.

5. Aluminoborosilicate glass with low dielectric constant and low dielectric loss according to claim 4, characterized in that: The fluoride is CaF2 or MgF2.

6. Aluminoborosilicate glass with low dielectric constant and low dielectric loss according to claim 1, characterized in that: The SiO2, Al2O3 and B2O3 satisfy the following relationship: 0.03≤B2O3 / (Al2O3+SiO2)≤0.

47.

7. Aluminoborosilicate glass with low dielectric constant and low dielectric loss according to claim 1, characterized in that: The SiO2, Al2O3, B2O3, R2O and RO satisfy the following relationship: 0≤R2O / (Al2O3+SiO2+B2O3+RO)≤0.

12.

8. Aluminoborosilicate glass with low dielectric constant and low dielectric loss according to claim 3, characterized in that: When the alkali metal oxides are Li2O, Na2O and K2O, Li2O, Na2O and K2O satisfy the following relationship: The 0≤(1.4Li2O+1.6K2O) / 1.76Na2O≤14.

32.

9. A method for preparing aluminoborosilicate glass with low dielectric constant and low dielectric loss according to any one of claims 1 to 8, characterized in that: The raw materials are melted, clarified and homogenized according to corresponding amounts, and then annealed at 600° C. to 650° C. for 3 h to 8 h to obtain aluminoborosilicate glass with low dielectric constant and low dielectric loss.

10. Use of the aluminoborosilicate glass with low dielectric constant and low dielectric loss as claimed in claim 9 in the preparation of integrated antennas, electronic packaging and micro-electromechanical system packaging.

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