Modified CBS glass powder and modification method, green ceramic tape, ceramic substrate and use
Patent Information
- Application Number
- CN202610842919.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-11
- Publication Date
- 2026-08-18
AI Technical Summary
[0004]作为通过流延工艺制备生瓷带的原料CBS玻璃粉体（钙硼硅微晶玻璃粉）具有粒径小、表面能高等特点，很容易发生团聚，形成二次粒子，无法表现出优异的表面积效应、体积效应等缺陷
本发明给出的CBS玻璃粉体的改性方法通过将干燥后的CBS玻璃粉体与无水乙醇混合并超声处理，保证粉体颗粒在液相中充分解聚、均匀分散，这是后续改性过程不发生团聚的前提。然后将用量为CBS玻璃粉体的1%~4%的铝酸酯偶联剂加热后并均匀分散的溶液中，由于铝酸酯偶联剂具有羧基(-COOH)和铝氧基团(-Al-O-)，所以铝酸酯偶联剂的羧基(-COOH)与CBS玻璃粉体表面的羟基(-OH)反应形成牢固的共价键，在CBS玻璃粉体表面形成一层致密的有机分子膜（该有机分子膜包含铝氧基团(-Al-O-)）。此包覆层使CBS玻璃粉体由原本的亲水性转变为亲有机性，表面能得以降低；。在烧结阶段，CBS玻璃粉体表面形成一层致密的有机分子膜中含有的活性铝中心，其分解后，铝氧基团残留于粉体表面，并转化为具有极高活性的纳米级非晶态Al2O3或铝氧活性中心，使其在CBS玻璃粉体表面均匀预置了一层与烧结过程中需要润湿和包裹的Al2O3结构相似的铝氧纳米晶核层。进入烧结致密化阶段，这层活性包覆层能主动诱导玻璃熔体在其上优先铺展，显著降低润湿角，引导熔体由内向外进行反应润湿与包裹，彻底避免了硅烷偶联剂和钛酸酯偶联剂分解后留下空洞与残碳所导致的包裹动力不足的熔体润湿性问题。此外，由铝酸酯改性剂引入的Al离子参与了玻璃-陶瓷界面的化学结构构建，高温下形成一个成分梯度平滑的互扩散过渡层，有效缓解了热膨胀系数差异导致的热应力，有效调控了界面活性，消除了界面微裂纹和孔隙，实现致密包裹。
Smart Images
Figure CN122586583A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of low-temperature co-fired ceramics technology, and specifically relates to a modified CBS glass powder and modification method, green ceramic belt, ceramic substrate and its uses. Background Technology
[0002] With the rapid development of electronic information technology, electronic products are accelerating their evolution towards miniaturization and lightweighting, necessitating high integration, reliability, and stability in electronic components. Against this backdrop, modularization and integration have become inevitable trends in component design. Low-temperature co-fired ceramics (LTCC) technology can encapsulate the three major passive components (capacitors, inductors, and resistors) and other passive components within a multilayer wiring substrate, meeting the requirements for high integration of electronic components and thus attracting widespread attention and importance both domestically and internationally.
[0003] LTCC technology uses a casting process to prepare a dense green ceramic tape with controllable thickness from low-temperature sintered ceramic powder. The desired circuit pattern is obtained on the green ceramic tape using processes such as laser drilling, micro-hole injection, and conductor paste printing. Passive and functional devices are then embedded in the ceramic substrate. After multi-layer lamination, the substrate is sintered at a temperature below 900°C in one step to create a composite substrate with integrated passive devices. The surface of the substrate can be further assembled with bare IC chips and micro passive components to form a functional modular circuit system.
[0004] CBS glass powder (calcium borosilicate microcrystalline glass powder), used as a raw material for preparing green ceramic tapes via tape casting, is characterized by its small particle size and high surface energy, making it prone to agglomeration and the formation of secondary particles. This results in a failure to exhibit excellent surface area and volume effects. Consequently, the distribution of CBS glass and Al2O3 in the tape-cast green ceramic tape is uneven. During lamination and sintering, the CBS glass cannot effectively wet and encapsulate Al2O3, leading to numerous irregular pores in the LTCC ceramic substrate. Therefore, surface modification of the CBS glass powder is necessary. While existing methods using silane coupling agents and titanate coupling agents to modify the surface of CBS glass powder can improve powder dispersibility during room temperature processing, the organic modified layer formed by these agents on the CBS glass powder surface suffers from fundamental defects such as the inability to control melt wettability and a lack of interfacial activity. Consequently, the modified CBS glass powder cannot effectively wet and encapsulate Al2O3 during sintering. Summary of the Invention
[0005] To address the shortcomings of the prior art, the present invention aims to provide a modified CBS glass powder and modification method, a green ceramic belt, a ceramic substrate, and its applications. By using an aluminate coupling agent to modify the surface of the CBS glass powder, the CBS glass powder is better dispersed in the slurry, and the glass and ceramic distribution in the green ceramic belt is more uniform. A dense LTCC ceramic substrate has been successfully prepared.
[0006] To solve the above-mentioned technical problems, this invention provides a method for modifying CBS glass powder, comprising the following steps: The dried CBS glass powder and anhydrous ethanol were mixed and ultrasonically treated to obtain a CBS glass powder-ethanol mixed solution; the purpose of ultrasonic treatment of CBS glass powder and anhydrous ethanol was to ensure that the powder particles did not agglomerate.
[0007] The aluminate coupling agent is melted and heated, and then added to a CBS glass powder-ethanol mixed solution for stirring and reaction. After the reaction, the surface modifier adsorbed by physical adsorption on the powder surface is removed by ultrasonic cleaning, and then the powder is dried to obtain modified CBS glass powder.
[0008] Aluminate coupling agents were used to modify the powder surface, improving the compatibility between the glass powder and the organic solvent, increasing the dispersion rate of the glass powder in the solvent medium, and achieving uniform dispersion of CBS glass powder particles and Al2O3 powder in the green ceramic belt. The amount of aluminate coupling agent used was 1% to 4% of the mass of the CBS glass powder, preferably 3% of the mass of the CBS glass powder.
[0009] When the amount of aluminate coupling agent exceeds 4% of the mass of CBS glass powder, the excess aluminate coupling agent in the system becomes entangled with the C chains coated on the surface of CBS glass powder particles, forming a network structure. This manifests macroscopically as the agglomeration of CBS glass powder and an increase in slurry viscosity.
[0010] Preferably, the preparation method of the CBS glass powder is as follows: CaCO3, H3BO3 and SiO2 are mixed and melted at 1400℃~1500℃ to obtain glass liquid; the glass liquid is cooled and shaped and then ground to obtain CBS glass powder, and the mass percentage content ratio of CaCO3, H3BO3 and SiO2 is 46%:25%:29%.
[0011] Preferably, the aluminate coupling agent is DL411. Compared with other coupling agents (such as titanate or borate), the inorganic powder after activation and modification treatment with the aluminate coupling agent has the advantages of stable quality, light color, non-toxicity, mild taste, wide range of applications, no need for diluents and hydrolysis, convenient use, and low price.
[0012] Preferably, the CBS glass powder and anhydrous ethanol in a mass ratio of 1:5 are ultrasonically treated for 1 to 3 hours, and the heated and melted aluminate coupling agent is added to the CBS glass powder-ethanol solution and reacted at 75°C for 5 to 7 hours. After the reaction, the ultrasonic cleaning time is 1 to 2 hours. The amount of aluminate coupling agent is 1% to 4% of the mass of CBS glass powder.
[0013] The melting reaction temperature is limited to 75℃ because the aluminate coupling agent is not reactive at too low a temperature, and the ethanol boiling modification effect is not good at too high a temperature; the ultrasonic cleaning time is limited to 1h~2h because excessive ultrasonic time can easily damage the surface network structure of the modified glass powder.
[0014] This invention provides a method for modifying CBS glass powder to prepare CBS glass powder.
[0015] A method for preparing a green ceramic belt includes the following steps: CBS glass powder and alumina powder were mixed in a ratio of 35:65, ball-milled and dried to obtain powder. The sintered substrate prepared by this powder ratio has the best performance. Organic solvent, dispersant and defoamer are added to the powder and then dispersed by ball milling. After one ball milling, binder and plasticizer are added. After a second ball milling, ceramic casting slurry with a viscosity of 600 mPa·s to 800 mPa·s is obtained. At this viscosity, the cast green ceramic tape has no cracks on the surface and the thickness is appropriate. The casting slurry is cast into a green ceramic tape.
[0016] Preferably, the solvent accounts for 40% to 60% of the powder mass, the dispersant accounts for 0.5% to 1.5% of the powder mass, the defoamer accounts for 1% to 1.5% of the powder mass, the binder accounts for 40% to 45% of the powder mass, and the plasticizer accounts for 3% of the powder mass.
[0017] Preferably, the solvent accounts for 50% of the powder mass, the dispersant accounts for 1% of the powder mass, the defoamer accounts for 1.2% of the powder mass, the binder accounts for 40% of the powder mass, and the plasticizer accounts for 3% of the powder mass. This organic formula is the optimal experimental formula in the early stage.
[0018] Preferably, the organic solvent is a mixture of xylene and ethanol in a mass ratio of 1:1; the dispersant is one or more of castor oil, polyvinylpyrrolidone, TEGO-700, or triethyl phosphate; the defoamer is an organic non-silicone polypropylene-based polyether; the binder is LS binder; and the plasticizer is dibutyl phthalate.
[0019] A method for preparing a ceramic substrate involves stacking, isostatically pressing, cutting, and sintering a green ceramic strip to obtain the ceramic substrate, wherein the sintering temperature is 800℃~900℃.
[0020] This invention provides a ceramic substrate prepared by the above method.
[0021] This invention provides the application of ceramic substrates in high-frequency packaged devices.
[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: The modification method for CBS glass powder provided in this invention involves mixing dried CBS glass powder with anhydrous ethanol and then ultrasonically treating it to ensure that the powder particles are fully deagglomerated and uniformly dispersed in the liquid phase. This is a prerequisite for preventing agglomeration in subsequent modification processes. Then, an aluminate coupling agent, at a concentration of 1% to 4% of the CBS glass powder, is heated and uniformly dispersed in the solution. Because the aluminate coupling agent has carboxyl groups (-COOH) and aluminoxy groups (-Al-O-), the carboxyl groups (-COOH) of the aluminate coupling agent react with the hydroxyl groups (-OH) on the surface of the CBS glass powder to form strong covalent bonds, resulting in a dense organic molecular film (containing aluminoxy groups (-Al-O-)) on the surface of the CBS glass powder. This coating layer transforms the CBS glass powder from its original hydrophilicity to an organophilicity, thereby reducing its surface energy. During the sintering stage, a dense organic molecular film forms on the surface of the CBS glass powder, containing active aluminum centers. After decomposition, the aluminum oxide groups remain on the powder surface and transform into highly active nanoscale amorphous Al2O3 or aluminum oxide active centers. This results in a uniformly pre-placed aluminum oxide nanocrystalline core layer on the CBS glass powder surface, similar in structure to the Al2O3 that needs to be wetted and coated during sintering. Entering the densification stage, this active coating layer actively induces the glass melt to preferentially spread on it, significantly reducing the wetting angle and guiding the melt to react, wet, and coat from the inside out. This completely avoids the melt wettability problem caused by insufficient coating power due to voids and residual carbon left after the decomposition of silane coupling agents and titanate coupling agents. In addition, the Al ions introduced by the aluminate modifier participate in the chemical structure construction of the glass-ceramic interface, forming a smooth interdiffusion transition layer with a compositional gradient at high temperature. This effectively alleviates the thermal stress caused by the difference in thermal expansion coefficients, effectively regulates the interfacial activity, eliminates interfacial microcracks and pores, and achieves dense encapsulation.
[0023] The aluminate coupling agent, firmly bonded to the surface of CBS glass powder, further reacts to form a thick and effective organic steric hindrance layer. Under this steric hindrance, the modified CBS glass powder achieves excellent and stable dispersion in the subsequent casting slurry system, resulting in a uniform distribution of CBS glass powder and Al2O3 filler in the cast green ceramic tape. Simultaneously, the aluminooxy groups (-Al-O-) grafted onto the surface of the CBS glass powder also tightly bind to the binder used to prepare the green ceramic tape through intermolecular forces. This unique amphiphilic structure makes the aluminate coupling agent a "molecular bridge" connecting the inorganic filler and the organic matrix. Ultimately, during the lamination sintering process, internal porosity of the substrate is eliminated, significantly improving the density of the LTCC ceramic substrate. Attached Figure Description
[0024] Figure 1 A flow chart of powder modification provided by the present invention.
[0025] Figure 2 The present invention provides XRD patterns of CBS glass powder before and after modification.
[0026] Figure 3 The present invention provides TG images of CBS glass powder before and after modification.
[0027] Figure 4 XPS spectra of CBS glass powder before and after modification are provided for this invention, wherein... Figure 4 (a) is the XPS spectrum of the modified CBS glass powder. Figure 4 (b) is the XPS spectrum of unmodified CBS glass powder. Figure 5 The present invention provides FT-IR spectra of CBS glass powder before and after modification.
[0028] Figure 6 A diagram illustrating the modification mechanism of CBS glass powder provided by this invention.
[0029] Figure 7 This invention provides FESEM-EDS microstructure images of CBS / Al2O3 green ceramic belts before and after modification, wherein... Figure 7 (a) is a FESEM-EDS microstructure of the CBS / Al2O3 green ceramic belt before modification. Figure 7 (b) is a FESEM-EDS microstructure of the modified CBS / Al2O3 green ceramic belt.
[0030] Figure 8 This invention provides FESEM microstructure images of a CBS / Al2O3 sintered substrate before and after modification, wherein... Figure 8 (a) is a FESEM microstructure image of the CBS / Al2O3 sintered substrate prepared in Comparative Example 2. Figure 8 (b) is a FESEM microstructure image of the CBS / Al2O3 sintered substrate prepared in Example 7. Figure 8 (c) is a FESEM microstructure image of the CBS / Al2O3 sintered substrate prepared in Example 8. Figure 8 (d) is a FESEM microstructure image of the CBS / Al2O3 sintered substrate prepared in Example 6. Figure 8 (e) FESEM microstructure of the CBS / Al2O3 sintered substrate prepared in Example 9.
[0031] Figure 9 The diagram shows the rheological and thixotropic properties of CBS / Al2O3 cast slurry before and after modification according to the present invention. Figure 9 (a) Rheological properties of CBS / Al2O3 cast slurry before and after modification. Figure 9 (b) shows the thixotropic properties of CBS / Al2O3 casting slurry before and after modification. Detailed Implementation
[0032] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods described in the embodiments of the present invention are conventional methods.
[0033] It should be noted that when numerical ranges are involved in this invention, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as in Examples 1 to 8, preferred embodiments are described in this invention to avoid redundancy. However, this invention is not limited to these, but can be specifically implemented in other ways within the scope of the technical solutions defined in the appended claims. All raw materials, reagents, instruments, and equipment used in the following embodiments of this invention can be purchased from the market or prepared by existing methods.
[0034] The following detailed description, in conjunction with embodiments of the present invention and accompanying drawings, provides a clear and complete illustration of the technical solutions in these embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0035] The preparation method of CBS glass powder is as follows: CaCO3, H3BO3 and SiO2 are mixed and melted at 1400℃~1500℃ to obtain glass liquid; the glass liquid is cooled and shaped and then ground to obtain CBS glass powder, wherein the mass percentage content of CaCO3, H3BO3 and SiO2 is 46%:25%:29%. The CBS glass powder in the following examples is all prepared by this method.
[0036] Example 1 like Figure 1 As shown, a method for preparing modified CBS glass powder includes the following steps: 50g of dried CBS glass powder and 200g of anhydrous ethanol were mixed and ultrasonically treated for 1 hour to obtain a CBS glass powder-ethanol mixed solution.
[0037] Weigh out DL-411 aluminate coupling agent according to 3 wt% of CBS glass powder, place DL-411 in a beaker and heat in an oven at 100℃. Add the melted DL-411 to a mixed solution of CBS glass powder and anhydrous ethanol, and react with magnetic stirring at 75℃ for 6 hours. After the reaction is complete, ultrasonically clean for 1 hour to remove the surface modifier physically adsorbed on the powder surface; then dry and sieve to obtain the final modified CBS glass powder.
[0038] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the CBS glass powder was not modified.
[0039] 50g of dried CBS glass powder was mixed with 200g of anhydrous ethanol and ultrasonically treated for 1 hour. After drying, CBS glass powder was obtained.
[0040] Example 2 like Figure 1 As shown, a method for preparing modified CBS glass powder includes the following steps: 50g of dried CBS glass powder and 200g of anhydrous ethanol were mixed and ultrasonically treated for 1 hour to obtain a CBS glass powder-ethanol mixed solution.
[0041] Weigh out DL-411 aluminate coupling agent according to 1 wt% of CBS glass powder mass, place DL-411 in a beaker and heat in an oven at 100℃. Add the melted DL-411 to a mixed solution of CBS glass powder and anhydrous ethanol, and react with magnetic stirring at 75℃ for 6 hours. After the reaction is complete, ultrasonically clean for 1 hour to remove the surface modifier physically adsorbed on the powder surface; then dry and sieve to obtain the finally modified CBS glass powder.
[0042] Example 3 like Figure 1 As shown, a method for preparing modified CBS glass powder includes the following steps: 50g of dried CBS glass powder and 200g of anhydrous ethanol were mixed and ultrasonically treated for 1 hour to obtain a CBS glass powder-ethanol mixed solution.
[0043] Weigh out DL-411 aluminate coupling agent according to 2wt% of CBS glass powder, place DL-411 in a beaker and heat in an oven at 100℃. Add the melted DL-411 to a mixed solution of CBS glass powder and anhydrous ethanol, and react with magnetic stirring at 75℃ for 7 hours. After the reaction is complete, ultrasonically clean for 1 hour to remove the surface modifier physically adsorbed on the powder surface. Then, dry and sieve to obtain the finally modified CBS glass powder.
[0044] Example 4 like Figure 1 As shown, a method for preparing modified CBS glass powder includes the following steps: 50g of dried CBS glass powder and 200g of anhydrous ethanol were mixed and ultrasonically treated for 1 hour to obtain a CBS glass powder-ethanol mixed solution.
[0045] Weigh out DL-411 aluminate coupling agent according to 4 wt% of CBS glass powder, place DL-411 in a beaker and heat in an oven at 100℃. Add the melted DL-411 to a mixed solution of CBS glass powder and anhydrous ethanol, and react with magnetic stirring at 75℃ for 6 hours. After the reaction is complete, ultrasonically clean for 1 hour to remove the surface modifier physically adsorbed on the powder surface; then dry and sieve to obtain the finally modified CBS glass powder.
[0046] The modified CBS glass powders that can be obtained in Examples 1 to 4 of the invention are used as examples in the following studies.
[0047] Example 5 like Figure 6 As shown, a method for preparing a green ceramic belt includes the following steps: 35 wt% of the modified CBS glass powder prepared in Example 1 was ball-milled, mixed and dried with 65 wt% alumina powder to obtain the powder. Add 50 wt% organic solvent (a mixture of xylene and ethanol at a mass ratio of 1:1), 1 wt% castor oil, and 1.2 wt% organic non-silicone polypropylene-based polyether to the powder. Pour the mixture into a ball mill jar and disperse and ball mill for 14 hours using a planetary ball mill. Then add 40 wt% LS binder and 3 wt% plasticizer, and ball mill for 8 hours to obtain a stable viscosity of 650 mPa·s (200 s⁻¹). -1 The slurry was cast using a casting machine at a casting speed of 20 cm / min to obtain a green ceramic tape with a thickness of 70 μm.
[0048] The density of the raw porcelain band is 2.09 g / cm³. 3 The tensile strength is 1.75 MPa.
[0049] The green ceramic tapes obtained from the tape casting process were then stacked, isostatically pressed, cut, and sintered at 850℃ to obtain a ceramic substrate. The density of the sintered substrate was measured to be 2.89 g / cm³. 3 The flexural strength is 219 MPa, the dielectric constant is 7.46 (1 MHz), and the dielectric loss is 1 x 10⁻⁶. -3 (1MHz).
[0050] Example 6 like Figure 6 As shown, a method for preparing a green ceramic belt includes the following steps: The modified CBS glass powder prepared in Example 2 (35 wt%) was ball-milled, mixed, and dried with 65 wt% alumina powder to obtain a powder. Add 50 wt% organic solvent (a mixture of xylene and ethanol at a mass ratio of 1:1), 1 wt% castor oil, and 1.2 wt% organic non-silicone polypropylene-based polyether to the powder. Pour the mixture into a ball mill jar and disperse and ball mill for 14 hours using a planetary ball mill. Then add 40 wt% LS binder and 3 wt% plasticizer, and ball mill for 8 hours to obtain a stable viscosity of 650 mPa·s (200 s⁻¹). -1 The slurry was cast using a casting machine at a casting speed of 20 cm / min to obtain a green ceramic tape with a thickness of 80 μm.
[0051] The density of the raw porcelain band is 1.88 g / cm³. 3 The tensile strength is 1.1 MPa.
[0052] The green ceramic tapes obtained by tape casting were stacked, isostatically pressed, cut, and sintered at 850℃ to obtain a ceramic substrate. The density of the sintered substrate was measured to be 2.79 g / cm³. 3 The flexural strength is 198 MPa, the dielectric constant is 7.24 (1 MHz), and the dielectric loss is 2.1 x 10⁻⁶. -3(1MHz).
[0053] Example 7 like Figure 6 As shown, a method for preparing a green ceramic belt includes the following steps: The modified CBS glass powder prepared in Example 3 was mixed with 65 wt% alumina powder and then ball-milled and dried to obtain the powder. Add 50 wt% organic solvent (a mixture of xylene and ethanol at a mass ratio of 1:1), 1 wt% castor oil, and 1.2 wt% organic non-silicone polypropylene-based polyether to the powder. Pour the mixture into a ball mill jar and disperse and ball mill for 14 hours using a planetary ball mill. Then add 40 wt% LS binder and 3 wt% plasticizer, and ball mill for 8 hours to obtain a stable viscosity of 650 mPa·s (200 s⁻¹). -1 The slurry was cast using a casting machine at a casting speed of 20 cm / min to obtain a green ceramic tape with a thickness of 70 μm.
[0054] The density of the raw porcelain band is 1.98 g / cm³. 3 The tensile strength is 1.77 MPa.
[0055] The green ceramic tapes obtained by tape casting were stacked, isostatically pressed, cut, and sintered at 850℃ to obtain a ceramic substrate. The density of the sintered substrate was measured to be 2.85 g / cm³. 3 The flexural strength is 201 MPa, the dielectric constant is 7.38 (1 MHz), and the dielectric loss is 1.6 x 10⁻⁶. -3 (1MHz).
[0056] Example 8 like Figure 6 As shown, a method for preparing a green ceramic belt includes the following steps: The modified CBS glass powder prepared in Example 4 was mixed with 65 wt% alumina powder, ball-milled and dried to obtain the powder. Add 50 wt% organic solvent (a mixture of xylene and ethanol at a mass ratio of 1:1), 1 wt% castor oil, and 1.2 wt% organic non-silicone polypropylene-based polyether to the powder. Pour the mixture into a ball mill jar and disperse and ball mill for 14 hours using a planetary ball mill. Then add 40 wt% LS binder and 3 wt% plasticizer, and ball mill for 8 hours to obtain a stable viscosity of 650 mPa·s (200 s⁻¹). -1 The slurry was cast using a casting machine at a casting speed of 20 cm / min to obtain a green ceramic tape with a thickness of 70 μm.
[0057] The density of the raw porcelain band is 1.89 g / cm³. 3The tensile strength is 1.25 MPa.
[0058] The green ceramic tapes obtained by tape casting were stacked, isostatically pressed, cut, and sintered at 850℃ to obtain a ceramic substrate. The density of the sintered substrate was measured to be 2.77 g / cm³. 3 The flexural strength is 198 MPa, the dielectric constant is 7.24 (1 MHz), and the dielectric loss is 1.7 x 10⁻⁶. -3 (1MHz).
[0059] Comparative Example 2 The difference between Comparative Example 2 and Example 6 is that the CBS glass powder was not modified.
[0060] The CBS glass powder obtained by 35 wt% of Comparative Example 1 was ball-milled, mixed and dried with 65 wt% alumina powder to obtain the powder. Add 50 wt% organic solvent (a mixture of xylene and ethanol at a mass ratio of 1:1), 1 wt% castor oil, and 1.2 wt% organic non-silicone polypropylene-based polyether to the powder. Pour the mixture into a ball mill jar and disperse and ball mill for 14 hours using a planetary ball mill. Then add 40 wt% LS binder and 3 wt% plasticizer, and ball mill for 8 hours to obtain a stable viscosity of 650 mPa·s (200 s⁻¹). -1 The slurry was cast using a casting machine at a casting speed of 20 cm / min to obtain a green ceramic tape with a thickness of 70 μm.
[0061] The density of the raw porcelain band is 1.80 g / cm³. 3 The tensile strength is 0.9 MPa.
[0062] The green ceramic tapes obtained by tape casting were stacked, isostatically pressed, cut, and sintered at 850℃ to obtain a ceramic substrate. The density of the sintered substrate was measured to be 2.74 g / cm³. 3 The flexural strength is 188 MPa, the dielectric constant is 7.1 (1 MHz), and the dielectric loss is 2.4 x 10⁻⁶. -3 (1MHz).
[0063] Comparative Example 3 The difference between Comparative Example 3 and Example 6 is that the aluminate coupling agent DL-411 coated with CBS glass powder was not melted and heated.
[0064] 50g of dried CBS glass powder was mixed with 200g of anhydrous ethanol. Simultaneously, 3wt% of aluminate coupling agent DL-411 (containing 3 wt% of the glass powder) was added to the CBS glass powder and anhydrous ethanol mixture, and the mixture was magnetically stirred at 60°C for 2 hours. The mixture was then dried and sieved to obtain the final modified CBS glass powder.
[0065] Modified 35wt% CBS glass powder and 65wt% alumina powder were ball-milled, dried, and then weighed into a ball mill jar. The mixture was then dispersed and ball-milled for 14 hours using a planetary ball mill. Finally, 40wt% LS binder and 3wt% plasticizer were added, and the mixture was ball-milled for another 8 hours to obtain a stable viscosity of 650 mPa·s (200 s⁻¹). -1 The slurry was cast using a casting machine at a casting speed of 20 cm / min to obtain a green ceramic tape with a thickness of 85 μm.
[0066] The density of the raw porcelain band is 1.87 g / cm³. 3 The tensile strength is 1.1 MPa.
[0067] The green ceramic tapes obtained by tape casting were stacked, isostatically pressed, cut, and sintered at 850℃ to obtain a ceramic substrate. The density of the sintered substrate was measured to be 2.75 g / cm³. 3 The flexural strength is 176 MPa, the dielectric constant is 7.17 (1 MHz), and the dielectric loss is 2.4 x 10⁻⁶. -3 (1MHz).
[0068] Examples 1 through 5 all successfully prepared modified CBS glass powder, and Examples 5 through 8 all successfully produced green ceramic tapes and ceramic substrates. The following is a preferred example of the ceramic substrates prepared in Examples 5 through 8, focusing on the performance of the green ceramic tape prepared in Example 5, and the specific research results of the modified CBS glass powder prepared in Example 1: (a) Structural confirmation (1) XRD like Figure 2 The XRD patterns of the modified CBS glass powder prepared in Example 1 and the CBS glass powder prepared in Comparative Example 1 are shown below. Figure 2 It can be seen that all peaks in the spectra of CBS glass powder before and after modification belong to the "bun peaks" of amorphous glass. By comparing the two curves, it can be found that the peak positions and intensities are similar and have not changed significantly, indicating that no new crystalline phase was generated in the CBS glass powder after modification.
[0069] (2) TG like Figure 3 The TG (thermogravimetric) diagrams of the modified CBS glass powder prepared in Example 1 and the CBS glass powder prepared in Comparative Example 1 are shown below. Figure 3 It can be seen that the CBS glass powder lost more mass after modification, mainly because the surface of the CBS glass powder was coated with a layer of organic matter, which indirectly proves that the surface modification of CBS glass powder was successful.
[0070] (3) XPS Figure 4 XPS (elemental analysis) plots of the modified CBS glass powder prepared in Example 1 and the CBS glass powder prepared in Comparative Example 1 are shown below. Figure 4 It can be seen that the carbon-to-oxygen ratio of the original CBS glass powder was only 0.69, while the carbon-to-oxygen ratio of the modified CBS glass powder reached 1.25. The main reason for the increase in carbon content is that the aluminate coupling agent containing long-chain C is coated on the powder surface, and new Al atoms appear. 2p The peak indirectly proves that the modification was successful.
[0071] (4) FT-IR Figure 5 The FT-IR spectra of the modified CBS glass powder prepared in Example 1 and the CBS glass powder prepared in Comparative Example 1 are shown below. Figure 5 It can be seen that the number of -OH groups in CBS glass powder is significantly reduced after modification, at 1728 cm⁻¹. -1 There is a C=O stretching vibration peak at 935 cm⁻¹. -1 The peak of Al-O stretching vibration.
[0072] (II) Structural and Performance Studies (1) FESEM-EDS microstructure image Figure 7 The images show the FESEM-EDS microstructures of the green ceramic ribbons prepared in Example 6 and Comparative Example 2. Figure 7 It can be seen that the CBS microcrystalline glass and Al2O3 are more evenly distributed in the modified green ceramic belt.
[0073] Figure 8 FESEM microstructure images of ceramic substrates prepared in Examples 6-9 and Comparative Example 2 are obtained by... Figure 8 It can be seen that the pores of the modified sintered substrate are greatly reduced compared to the unmodified substrate, and the sintered substrate is more dense.
[0074] Figure 9 The rheological and thixotropic properties of the casting pastes for ceramic substrates prepared in Examples 6-9 and Comparative Example 2 are shown in the diagram. Figure 9 It can be seen that the modified slurry has the lowest viscosity, better fluidity, and better thixotropy.
[0075] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.
Claims
1. A method for modifying CBS glass powder, characterized in that, Includes the following steps: The dried CBS glass powder and anhydrous ethanol were mixed and ultrasonically treated to obtain a CBS glass powder-ethanol mixed solution. The aluminate coupling agent was melted and heated, and the melted aluminate coupling agent was added to a CBS glass powder-ethanol mixed solution and stirred to react. After the reaction, the modified CBS glass powder was obtained by ultrasonic cleaning and drying. The amount of aluminate coupling agent used is 1% to 4% of the mass of CBS glass powder, and the mass ratio of CBS glass powder to anhydrous ethanol is 1:4 to 5.
2. The method for modifying CBS glass powder according to claim 1, characterized in that, The method for preparing the CBS glass powder includes the following steps: CaCO3, H3BO3 and SiO2 are mixed and melted at 1400℃~1500℃ to obtain molten glass; the molten glass is cooled, shaped and then ground to obtain CBS glass powder. The mass percentage ratio of CaCO3, H3BO3 and SiO2 is 46%:25%:29%.
3. The method for modifying CBS glass powder according to claim 1, characterized in that, The ultrasonic treatment of the CBS glass powder and anhydrous ethanol lasts for 1 to 3 hours. The heated and melted aluminate coupling agent is added to the CBS glass powder-ethanol solution and reacted at 70 to 80°C for 5 to 7 hours. After the reaction, the ultrasonic cleaning lasts for 1 to 2 hours.
4. CBS glass powder is prepared by the modification method of CBS glass powder according to any one of claims 1 to 3.
5. A method for preparing a green ceramic belt, characterized in that, Includes the following steps: The CBS glass powder described in claim 4 and alumina powder are mixed, ball-milled and dried at a mass percentage of 35:65 to obtain the powder. Organic solvent, dispersant and defoamer are added to the powder and then dispersed by ball milling. After one ball milling, binder and plasticizer are added, and then a second ball milling is performed to obtain a cast slurry with a viscosity of 600 mPa·s to 800 mPa·s. The above-mentioned casting slurry is cast into a green ceramic tape.
6. The method for preparing the green ceramic belt according to claim 5, characterized in that, The solvent accounts for 40% to 60% of the powder mass, the dispersant accounts for 0.5% to 1.5% of the powder mass, the defoamer accounts for 1% to 1.5% of the powder mass, the binder accounts for 40% to 45% of the powder mass, and the plasticizer accounts for 3% of the powder mass.
7. The method for preparing the green ceramic belt according to claim 5, characterized in that, The organic solvent is a mixture of xylene and ethanol in a mass ratio of 1:1; the dispersant is at least one of castor oil, polyvinylpyrrolidone, TEGO-700, or triethyl phosphate; the defoamer is an organic non-silicone polypropylene-based polyether; the binder is LS binder; and the plasticizer is dibutyl phthalate.
8. A method for preparing a ceramic substrate, characterized in that, The green ceramic strip described in claim 5 is subjected to stacking, isostatic pressing, cutting, and sintering to obtain a ceramic substrate, wherein the sintering temperature is 800℃~900℃.
9. The ceramic substrate prepared by the method for preparing the ceramic substrate according to claim 8.
10. The application of the ceramic substrate according to claim 9 in high-frequency packaging devices.