Electronically graded low thermal expansion coefficient glass fibers and methods for making the same

Abstract

The application belongs to the technical field of glass fibers, and particularly relates to electronic-grade low-thermal-expansion-coefficient glass fibers and a preparation method thereof. The electronic-grade low-thermal-expansion-coefficient glass fibers are composed of the following components in mass percentage: SiO2 55.0-63.0%, Al2O3 18.1-23.5%, B2O3 4.1-9.9%, MgO 5.1-12.0%, WO3 0.1-3.0%, ZnO 0.1-4.5%, TiO2 0.1-3.5%, Fe2O3 0.1-0.7%, SnO2 0.1-0.7%, Li2O 0.1-0.7%, and trace impurities as the balance. The application can effectively reduce the crystallization risk and the number of bubbles in the production process, significantly improve the quality of the glass fiber product, and be conducive to realizing industrialized large-scale production. The electronic-grade low-thermal-expansion-coefficient glass fibers have excellent comprehensive performance and can meet the application requirements in the chip packaging field.

Description

Technical Field

[0001] This invention belongs to the field of glass fiber technology, specifically relating to an electronic-grade glass fiber with a low coefficient of thermal expansion and its preparation method. Background Technology

[0002] Currently, the cutting-edge information industry, represented by AI computing power, is experiencing rapid development. Core hardware such as computing chips and large-size packaging substrates are continuously evolving towards higher integration, higher power density, and miniaturization, placing higher demands on the comprehensive performance and large-scale supply capacity of electronic-grade glass fiber, a key basic material. Against this backdrop, low-thermal-expansion glass fiber and its products have stood out due to their unique combination of low thermal expansion coefficient and high modulus, becoming an indispensable core substrate in the fields of chips and large-size packaging substrates.

[0003] However, the preparation and application of low thermal expansion electronic glass fiber still face significant industry bottlenecks: On the one hand, existing low thermal expansion glass fiber formulations and preparation processes struggle to achieve the synergistic effect of low thermal expansion coefficient and high modulus performance. Although some products exhibit low thermal expansion characteristics, their mechanical properties are significantly reduced, failing to meet the structural support requirements of encapsulation substrates. On the other hand, existing preparation processes suffer from poor stability and high product defect rates. During mass production, low thermal expansion glass is prone to crystallization during melting, and bubble defects are difficult to control. The presence of crystallized phases and bubbles not only leads to frequent fiber breakage during high-speed drawing processes, severely disrupting production continuity, but also results in poor batch performance stability, making it difficult to achieve large-scale and efficient continuous mass production. This fails to meet the rigid supply demands of the AI ​​computing power industry for large-volume, high-quality, and highly consistent core basic materials.

[0004] Although existing technologies have conducted a series of formulation adjustments and process optimization studies on low thermal expansion glass fibers, the improvements have mostly focused on improving single performance indicators (such as the coefficient of thermal expansion), failing to fundamentally solve the synergistic challenge of low thermal expansion, low defects, high modulus, and scalable continuous production of low thermal expansion glass fibers. Chinese patent CN103347831A discloses a glass composition with a low coefficient of thermal expansion and glass fibers made therefrom. The glass composition includes about 55-64 (excluding 64) wt% silicon dioxide, about 15-30 wt% aluminum oxide, about 5-15 wt% magnesium oxide, about 3-10 wt% boron oxide, about 0-11 wt% calcium oxide, and about 0-2 wt% alkali metal oxides, with the balance being less than about 1 wt% trace compounds. In this patent, the process window ΔT3 is relatively narrow, and the glass viscosity is high, the operating temperature range is small, and the production molding is difficult, posing significant challenges in actual industrial production. Summary of the Invention

[0005] The purpose of this invention is to provide an electronic-grade glass fiber with a low coefficient of thermal expansion. This glass fiber has the characteristics of low defects, low coefficient of thermal expansion, high modulus, and scalable continuous preparation, making it suitable for AI computing power substrates and meeting the application requirements of packaging carriers. This invention also provides a method for preparing electronic-grade glass fiber with a low coefficient of thermal expansion.

[0006] The electronic-grade low thermal expansion coefficient glass fiber of this invention comprises, by mass percentage, the following components: SiO2 55.0-63.0% Al2O3 18.1-23.5% B2O3 4.1-9.9% MgO 5.1-12.0% WO3 0.1-3.0% ZnO 0.1-4.5% TiO2 0.1-3.5% Fe2O3 0.1-0.7% SnO2 0.1-0.7% Li2O 0.1-0.7% Trace impurities remaining; in, WO3 + ZnO + TiO2 1.0-9.0% WO3 / (ZnO+TiO2) 0.14-0.56 B2O3 / (Al2O3 +ZnO) 0.21-0.45.

[0007] The coefficient of thermal expansion of electronic-grade low-thermal-expansion glass fiber is 2.38-2.95×10⁻⁶. -6 / ℃.

[0008] The diameter of electronic-grade glass fiber with low thermal expansion coefficient is 4-8 μm.

[0009] The elastic modulus of electronic-grade low thermal expansion glass fiber is 87-92 GPa.

[0010] The method for preparing electronic-grade low thermal expansion coefficient glass fiber according to the present invention includes the following steps: (1) Weigh the raw materials and mix them evenly to obtain the batch; (2) The batch materials are melted to obtain molten glass; (3) After the glass melt is clarified, it flows out through the baffle plate and is drawn into electronic grade low thermal expansion coefficient glass fiber.

[0011] Step (1) According to the content of each component in electronic grade low thermal expansion coefficient glass fiber, a pulse pneumatic mixer is used to mix the batch to achieve a high degree of uniformity and ensure that the proportion of each component meets the design composition requirements, laying the foundation for subsequent melting and glass fiber performance control.

[0012] The melting temperature in step (2) is 1400-1700℃.

[0013] In step (3), during clarification, low-speed stirring is performed at the front end of the clarification zone. A bubbling device is set at the bottom of the middle part of the clarification zone and inert gas is introduced. The gas flow rate is precisely controlled to be 0.5-2L / min, so that the clarification zone maintains a stable oxidation-reduction atmosphere throughout the process, thereby promoting the orderly floating and discharge of bubbles, while improving the uniformity of glass components and enhancing the homogenization and clarification effect of the glass melt.

[0014] In step (3), the number of holes in the stencil is 800-2000.

[0015] In step (3), the temperature of the stencil is 1300-1450℃.

[0016] In step (3), the inside of the stencil is equipped with a flow guiding structure, preferably a flow guiding groove or a flow guiding ridge, which can accurately control the flow direction of the glass liquid, avoid backflow and eddy current generation of the glass liquid, effectively reduce the risk of crystallization and secondary bubble generation during the glass forming process, and ensure the continuity of the drawing operation.

[0017] The components of the electronic-grade low thermal expansion coefficient glass fiber in this invention are described below: As a glass network forger, SiO2 has high bond energy in its Si-O bonds, enabling it to form a stable three-dimensional network structure and giving the glass an extremely low coefficient of thermal expansion. However, excessive SiO2 content will significantly increase the glass melting temperature, making fiber formation difficult, while excessively low SiO2 content will lead to a significant increase in the coefficient of thermal expansion. Therefore, the electronic-grade low coefficient of thermal expansion glass fibers in this invention limit the SiO2 content to 55.0-63.0%.

[0018] Al2O3 is a network intermediate, mainly existing in two coordination forms: [AlO4] and [AlO6]. [AlO4] can act as a network formant, connecting with [SiO4] through Si-O-Al bonds, increasing the degree of polymerization of the glass network, which helps to reduce the coefficient of thermal expansion and increase the elastic modulus. However, because the tetrahedral volume of [AlO4] is larger and its structure is more porous than that of [SiO4], excessively high Al2O3 content will cause an increase in the coefficient of thermal expansion and significantly increase the high-temperature viscosity of the glass and the tendency for cordierite crystals to crystallize. Therefore, in this invention, the Al2O3 content of electronic-grade low-thermal-expansion glass fibers is limited to 18.1-23.5%.

[0019] B2O3 is also a network forgery, possessing a low coefficient of thermal expansion and good fluxing properties. In the high-temperature molten state, B2O3 mainly exists as boron-oxygen trigonal [BO3], effectively reducing the high-temperature viscosity of glass and promoting glass clarification. In the low-temperature glassy state, some boron can transform into boron-oxygen tetrahedra [BO4] and combine with [SiO4] to form a denser borosilicate network structure, which is beneficial for further reducing the coefficient of thermal expansion. However, excessively high B2O3 content leads to a significant decrease in the elastic modulus of the glass. Therefore, in this invention, the electronic-grade low coefficient of thermal expansion glass fiber has a B2O3 content limited to 4.1-9.9%.

[0020] MgO belongs to the network exooxide category, Mg 2+ With a small radius, high charge, and strong polarization ability, it has a strong network aggregation effect, which can improve the degree of polymerization and elastic modulus of the glass network. However, when the MgO content is too high, it will not only increase the coefficient of thermal expansion, but also easily induce the precipitation of stable cordierite crystals. These crystals will form structural defects, causing fiber drawing interruption during the fiber forming process and seriously affecting the fiber forming efficiency. Therefore, in this invention, the electronic-grade low coefficient of thermal expansion glass fiber, based on reasonable control of SiO2 and Al2O3 content, limits the MgO content to 5.1-12.0%.

[0021] TiO2 is an intermediate oxide in the glass network. Under conditions of sufficient free oxygen content in the glass system, most Ti ions participate in the construction of the three-dimensional glass network in the form of [TiO4] tetrahedral, which can strengthen the network structure and help reduce the coefficient of thermal expansion. A small amount of Ti ions exist in the network gaps in the form of [TiO6] octahedral. TiO2 itself has the properties of a nucleating agent, and excessive addition can easily induce glass crystallization defects. Therefore, in order to comprehensively control the network reinforcement effect and the risk of crystallization, the TiO2 content of the electronic-grade low coefficient of thermal expansion glass fiber in this invention is limited to 0.1-3.5%.

[0022] This invention creatively introduces WO3 as a highly crosslinking promoter for glass networks. 6+ It mainly participates in the glass network construction in the form of [WO4] tetrahedral configuration. With its high ionic field strength, WO3 can establish additional cross-linking connections between [TiO4] units and between [SiO4] basic network units through WO-Ti and WO-Si heterobridged oxygen bonds. This effect effectively increases the proportion of bridging oxygen in the glass network, promotes the densification of the glass network structure, thereby improving the elastic modulus of the glass while suppressing the thermally induced expansion of the network spacing and reducing the coefficient of thermal expansion.

[0023] When the free oxygen content in a glass system is sufficient, ZnO tends to transform from a [ZnO6] octahedral configuration to a [ZnO4] tetrahedral configuration and embed itself in the glass network structure. This configurational transformation helps to enhance the strength of the glass network skeleton and increase the degree of network polymerization, thereby achieving the technical effects of reducing the coefficient of thermal expansion and increasing the elastic modulus of the glass. However, excessive ZnO addition will destroy the integrity of the glass network structure, causing the coefficient of thermal expansion to increase in the opposite direction. This invention introduces WO3 to address excess ZnO. 2+ Provides heterobridged oxygen binding sites, enabling Zn 2+ By embedding WO-Zn bridging bonds into the network units, the stability of the glass network structure is ensured while improving network coherence and resistance to deformation.

[0024] In this invention, WO3, TiO2, and ZnO form a synergistic mechanism of "crosslinking-skeleton-filling". TiO2 participates in the construction of the glass main network as [TiO4] tetrahedra and together with [SiO4] forms a rigid skeleton. An appropriate amount of ZnO transforms from [ZnO6] octahedra to [ZnO4] tetrahedra and embeds itself in the network gaps, playing a role in structural filling and improving the degree of polymerization. WO3, with its high ionic field strength, acts as a highly efficient crosslinking agent in the [WO4] configuration, establishing additional crosslinks between skeleton units through multiple heterobridged oxygen bonds of WO-Ti, WO-Si, and WO-Zn, and anchoring excess Zn. 2+ To prevent network deagglomeration caused by excessive ZnO introduction, the synergistic effect of WO3, TiO2, and ZnO makes the glass structure network denser, reduces volume changes caused by thermal vibration, and significantly reduces the coefficient of thermal expansion while maintaining the elastic modulus. However, when the WO3 content exceeds 3.0%, the glass elastic modulus decreases, and the coefficient of thermal expansion tends to increase; at the same time, tungstate crystal phases are generated, which adversely affect glass fiber formation and performance stability. Therefore, in this invention, the electronic-grade low coefficient of thermal expansion glass fiber is limited to a WO3 content of 0.1-3.0%, a ZnO content of 0.1-4.5%, and a total content of WO3+ZnO+TiO2 of 1.0-9.0%, preferably 1.5-8.5%, while limiting the WO3 / (ZnO+TiO2) ratio to 0.14-0.56.

[0025] Since ZnO reacts with alumina to form spinel during production, this invention enhances the phase competition effect during melt cooling by introducing a multi-component combination of WO3, ZnO, and TiO2. This effect effectively suppresses the crystallization tendency of the glass system and lowers the liquidus temperature of the glass. Furthermore, this invention optimizes and controls the crystallization behavior of the glass by introducing B2O3 and precisely controlling its relative content with Al2O3 and ZnO, limiting the B2O3 / (Al2O3+ZnO) ratio to 0.21-0.45. This induces the mullite phase to preferentially precipitate from the glass, achieving a transformation of the glass's main crystalline phase. The mullite phase has a low formation temperature and is easily melted, significantly reducing glass fiber drawing interruptions caused by crystallization defects and ensuring production efficiency.

[0026] The electronic-grade low thermal expansion coefficient glass fiber of the present invention introduces SnO2. The oxygen released by SnO2 through the valence state change at high temperature can cause the bubbles in the glass melt to float and be eliminated, thereby improving the glass clarification effect and melt quality. However, if the SnO2 content is too high, the thermal expansion coefficient will increase. The electronic-grade low thermal expansion coefficient glass fiber of the present invention limits the SnO2 content to 0.1-0.7%.

[0027] Li₂O, as a network modifier, can effectively reduce the surface tension of glass, facilitating the rise and expulsion of bubbles in the molten glass, thereby further enhancing the refining effect. In addition, Li₂O can lower the refining process temperature, reduce the erosion of refractory materials by the high-temperature melt, and help extend the furnace life. However, adding Li₂O alone will lead to an increase in the coefficient of thermal expansion and a decrease in the elastic modulus of glass, while W in WO₃... 6+ It has high field strength, which can strengthen the glass network structure and confine Li + Migration inhibits the increase in thermal expansion coefficient caused by Li2O and improves the elastic modulus. Li2O can reduce the high-temperature viscosity of glass, improve heat transfer efficiency, and reduce internal defects. At the same time, the free oxygen provided by Li2O can promote the smooth integration of WO3 into the glass network and ensure its stable existence, so as to fully exert the high field intensity control effect of WO3. Through the dual synergistic effect of process and performance, WO3 and Li2O achieve simultaneous optimization of refining efficiency, thermal expansion coefficient, and elastic modulus. The electronic-grade low thermal expansion coefficient glass fiber of this invention limits the Li2O content to 0.1-0.7%.

[0028] The present invention introduces a certain amount of Fe2O3 into electronic-grade low thermal expansion coefficient glass fiber. 3+A triangular pyramidal network structure can be formed in the glass network, which strengthens the glass network structure and increases the connection between [SiO4] and [AlO4], thereby improving the elastic modulus of the glass. However, excessive Fe2O3 will increase the coefficient of thermal expansion, and the severe coloration of Fe2O3 will affect the heat transmission of the molten glass, which is not conducive to the control of the temperature of the molten glass in the furnace. The electronic-grade low coefficient of thermal expansion glass fiber of the present invention limits the Fe2O3 content to 0.1-0.7%.

[0029] Without departing from the scope of this invention, the electronic-grade low thermal expansion coefficient glass fiber of this invention may contain trace impurities that are not actively added and coexist with other components. The trace impurities include one or more of ZrO2, Na2O, K2O, CaO, Cr2O3 or F2, and the content of the trace impurities is ≤0.5wt%.

[0030] The beneficial effects of this invention are as follows: (1) This invention utilizes the combined effect of directional atmosphere control and low-speed stirring to achieve the micro-disturbance effect formed by the uniform floating of the blown gas, combined with the disturbance effect of low-speed stirring on the melt, which can deeply remove micron-sized bubbles inside the glass melt and promote the uniformity of glass components, significantly improving the purification effect and uniformity of the glass melt; the blowing of inert gas can suppress the abnormal fluctuation of the valence state of variable valence metal ions in the glass melt, and at the same time weaken the material exchange between the furnace refractory material and the glass melt interface, thereby reducing the formation of heterogeneous crystal nuclei and microcrystal growth from the source, avoiding defects such as streaks, stones and crystal precipitation in the glass melt, and significantly improving the homogeneity and forming stability of the glass melt.

[0031] (2) Introducing the metal cation Zn into the aluminosilicate glass system 2+ During the production process, spinel is easily precipitated, leading to glass defects and causing fiber drawing interruptions. This invention addresses this by rationally controlling the content of key components in the glass fiber, specifically introducing WO3 and limiting its content to 0.1-3.0%, while limiting the WO3 / (ZnO+TiO2) ratio to 0.14-0.56 and the B2O3 / (Al2O3+ZnO) ratio to 0.21-0.45. By enhancing the competition between crystal phases within the system, the precipitation of spinel crystals is effectively suppressed, while the preferential precipitation of mullite crystals is promoted. This significantly reduces glass fiber drawing interruptions caused by crystallization defects, ensuring production efficiency, effectively controlling production costs, and possessing advantages for large-scale continuous production.

[0032] (3) The electronic-grade low thermal expansion coefficient glass fiber of the present invention introduces WO3, TiO2 and ZnO and forms a “cross-linking-skeleton-filling” synergistic mechanism, which effectively improves the degree of polymerization of the glass network, makes the glass structure network more compact, reduces the volume change caused by thermal vibration, significantly reduces the glass expansion coefficient and greatly improves the elastic modulus.

[0033] (4) The electronic-grade low thermal expansion coefficient glass fiber of the present invention introduces SnO2 and Li2O, and with the help of the synergistic effect between Li2O and WO3, while ensuring low thermal expansion coefficient and high elastic modulus, it effectively improves the glass clarification effect, reduces glass defects, and extends the furnace life.

[0034] (5) This invention can effectively reduce the risk of crystallization and the number of bubbles in the production process, significantly improve the quality of glass fiber products, and facilitate industrial-scale production; the coefficient of thermal expansion of electronic-grade low thermal expansion glass fiber is 2.38-2.95×10 -6 With an elastic modulus of 87-92 GPa and low bubble content, it has excellent overall performance and can meet the application requirements of the chip packaging field. Detailed Implementation

[0035] The present invention will be further described below with reference to embodiments.

[0036] Example 1 Preparation of electronic-grade glass fibers with low coefficient of thermal expansion: (1) Weigh the raw materials according to the content of each component in electronic grade low thermal expansion glass fiber and mix them evenly to obtain the compound material; (2) The batch material is put into the furnace and melted in the melting zone. The temperature of the melting zone is controlled at 1500℃ to obtain molten glass; (3) The glass melt is clarified in the clarification zone. During clarification, nitrogen gas (flow rate of 0.5 L / min) is blown into the bottom of the clarification zone and stirred at low speed simultaneously. After clarification, the glass melt flows out through an 800-hole stencil at 1340℃ (with a guide groove inside the stencil). It is then coated with oil by an oiler and wound and drawn into fibers by a wire drawing machine to obtain electronic-grade low thermal expansion coefficient glass fibers with a diameter of 4-8 μm.

[0037] Performance testing of electronic-grade low thermal expansion coefficient glass fiber: (a) Coefficient of thermal expansion: an index for evaluating the linear thermal expansion of glass, tested according to ASTM E228 standard, measuring the coefficient of thermal expansion in the range of 25-200℃; (ii) Molding temperature: The molding temperature of the glass fiber (lg3.0) was tested using a high-temperature viscometer, which is the temperature at which the viscosity of the glass is 1000 Poise; (iii) Liquidus temperature: The liquidus temperature of the glass is tested using a crystallization furnace in accordance with ASTM C829 standard. This is the critical temperature at which the glass begins to crystallize, and is generally the upper limit of the glass crystallization temperature. (iv) ΔT: The difference between the molding temperature and the liquidus temperature; (v) Elastic modulus: Characterizes the glass’s ability to resist elastic deformation, and is tested according to ASTM E1876 standard; (vi) Main crystal phase type: The crystalline material is tested and evaluated using a polarizing microscope combined with XRD. Cordierite crystal phase is abbreviated as CRD, mullite crystal phase is abbreviated as BM, and spinel crystal phase is abbreviated as ZAO. (vii) Number of bubbles: Take a certain amount of glass beads under the stencil and observe them using a microscope.

[0038] Example 2 Preparation of electronic-grade glass fibers with low coefficient of thermal expansion: (1) Weigh the raw materials according to the content of each component in electronic grade low thermal expansion glass fiber and mix them evenly to obtain the compound material; (2) The batch material is put into the furnace and melted in the melting zone. The temperature of the melting zone is controlled at 1400℃ to obtain molten glass; (3) The glass melt is clarified in the clarification zone. During clarification, nitrogen gas (flow rate of 1.2 L / min) is blown into the bottom of the clarification zone and stirred at low speed simultaneously. After clarification, the glass melt flows out through a 2000-hole stencil at 1300℃ (with a guide groove inside the stencil). It is then coated with oil by an oiler and wound and drawn into fibers by a wire drawing machine to obtain electronic-grade low thermal expansion coefficient glass fibers with a diameter of 4-8 μm.

[0039] The performance testing of electronic-grade low thermal expansion coefficient glass fiber was the same as in Example 1.

[0040] Example 3 Preparation of electronic-grade glass fibers with low coefficient of thermal expansion: (1) Weigh the raw materials according to the content of each component in electronic grade low thermal expansion glass fiber and mix them evenly to obtain the compound material; (2) The batch material is put into the furnace and melted in the melting zone. The temperature of the melting zone is controlled at 1700℃ to obtain molten glass; (3) The glass melt is clarified in the clarification zone. During clarification, nitrogen gas (flow rate of 2.0 L / min) is blown into the bottom of the clarification zone and stirred at low speed simultaneously. After clarification, the glass melt flows out through a 1600-hole stencil at 1450℃ (with a guide groove inside the stencil). It is then coated with oil by an oiler and wound and drawn into fibers by a wire drawing machine to obtain electronic-grade low thermal expansion coefficient glass fibers with a diameter of 4-8 μm.

[0041] The performance testing of electronic-grade low thermal expansion coefficient glass fiber was the same as in Example 1.

[0042] Examples 4-8 Based on the content of each component in the electronic-grade low thermal expansion coefficient glass fiber, the raw materials were accurately weighed, and other operations were the same as in Example 1 to obtain electronic-grade low thermal expansion coefficient glass fiber.

[0043] Table 1 shows the content and performance data of electronic-grade low thermal expansion coefficient glass fiber components in Examples 1-8.

[0044] Table 1. Content and performance data of electronic-grade low thermal expansion coefficient glass fiber components in Examples 1-8

[0045] Comparative Example 1 The WO3 content was adjusted to 2.9%, the ZnO content to 4.3%, and the TiO2 content to 0.5%, so that WO3 / (ZnO+TiO2) was 0.60. Other operations were the same as in Example 3, and electronic-grade glass fiber with low thermal expansion coefficient was obtained.

[0046] Comparative Example 2 The WO3 content was adjusted to 0.8%, the ZnO content to 4.1%, and the TiO2 content to 2.8%, so that WO3 / (ZnO+TiO2) was 0.12. Other operations were the same as in Example 3, and electronic-grade glass fiber with low thermal expansion coefficient was obtained.

[0047] Comparative Example 3 The B2O3 content was adjusted to 4.6% and the Al2O3 content to 21.9%, so that the B2O3 / (Al2O3+ZnO) ratio was 0.17. Other operations were the same as in Example 3, and electronic-grade glass fiber with low thermal expansion coefficient was obtained.

[0048] Comparative Example 4 The B2O3 content was adjusted to 9.9% and the ZnO content to 2.6%, so that the B2O3 / (Al2O3+ZnO) ratio was 0.47. Other operations were the same as in Example 3, and electronic-grade glass fiber with low thermal expansion coefficient was obtained.

[0049] Comparative Example 5 Nitrogen gas was not introduced during the preparation process, and other operations were the same as in Example 3, resulting in electronic-grade glass fiber with a low coefficient of thermal expansion.

[0050] Comparative Example 6 The Li2O content was adjusted to 0, the WO3 content to 2.08%, and other operations were the same as in Example 3, to obtain electronic-grade glass fiber with a low coefficient of thermal expansion.

[0051] Comparative Example 7 The WO3 content was adjusted to 0, the SiO2 content to 58.67%, and other operations were the same as in Example 3, to obtain electronic-grade glass fiber with a low coefficient of thermal expansion.

[0052] Table 2. Content and performance data of electronic-grade low thermal expansion coefficient glass fiber components in Comparative Examples 1-7

[0053] Analysis of Examples 1-8 and Comparative Examples 1-7 shows that the electronic-grade low thermal expansion coefficient glass fiber of the present invention has both a high elastic modulus and a low thermal expansion coefficient. At the same time, it also has a relatively low amount of bubbles and a tendency for the precipitation of cordierite and spinel crystal phases, which is beneficial for industrial production.

Claims

1. An electronic-grade glass fiber with a low coefficient of thermal expansion, characterized in that, It consists of the following components by weight percentage: SiO2 55.0-63.0% Al2O3 18.1-23.5% B2O3 4.1-9.9% MgO 5.1-12.0% WO3 0.1-3.0% ZnO 0.1-4.5% TiO2 0.1-3.5% Fe2O3 0.1-0.7% SnO2 0.1-0.7% Li2O 0.1-0.7% Trace impurities remaining; in, WO3 + ZnO + TiO2 1.0-9.0% WO3 / (ZnO+TiO2) 0.14-0.56 B2O3 / (Al2O3 +ZnO) 0.21-0.

45.

2. The electronic-grade low thermal expansion coefficient glass fiber according to claim 1, characterized in that... The coefficient of thermal expansion of electronic-grade low-thermal-expansion glass fiber is 2.38-2.95×10⁻⁶. -6 / ℃.

3. The electronic-grade low thermal expansion coefficient glass fiber according to claim 1, characterized in that... The diameter of electronic-grade glass fiber with low thermal expansion coefficient is 4-8 μm.

4. The electronic-grade low thermal expansion coefficient glass fiber according to claim 1, characterized in that... The elastic modulus of electronic-grade low thermal expansion glass fiber is 87-92 GPa.

5. A method for preparing electronic-grade low thermal expansion coefficient glass fiber according to any one of claims 1-4, characterized in that... The steps include the following: (1) Weigh the raw materials and mix them evenly to obtain the batch; (2) The batch materials are melted to obtain molten glass; (3) After the glass melt is clarified, it flows out through the baffle plate and is drawn into electronic grade low thermal expansion coefficient glass fiber.

6. The method for preparing electronic-grade low thermal expansion coefficient glass fiber according to claim 5, characterized in that... The melting temperature in step (2) is 1400-1700℃.

7. The method for preparing electronic-grade low thermal expansion coefficient glass fiber according to claim 5, characterized in that... During clarification in step (3), the mixture is stirred and inert gas is bubbled in.

8. The method for preparing electronic-grade low thermal expansion coefficient glass fiber according to claim 5, characterized in that... In step (3), the number of holes in the stencil is 800-2000.

9. The method for preparing electronic-grade low thermal expansion coefficient glass fiber according to claim 5, characterized in that... In step (3), the temperature of the stencil is 1300-1450℃.

10. The method for preparing electronic-grade low thermal expansion coefficient glass fiber according to claim 5, characterized in that... In step (3), a flow guiding structure is provided inside the sluice plate.

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