A mid-temperature co-fired electrode paste, a preparation method thereof and a metal electrode
By combining copper powder and titanium nitride powder in the medium-temperature co-fired electrode slurry, the problems of high energy consumption and high resistance of high-temperature co-fired ceramics are solved, achieving high conductivity and mechanical strength in the medium temperature range, which is suitable for modern electronic devices.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NO 43 INST OF CHINA ELECTRONICS TECH GRP CETC
- Filing Date
- 2026-02-05
- Publication Date
- 2026-06-02
AI Technical Summary
The high energy consumption and high resistance of existing high-temperature co-fired ceramic technology make it difficult to meet the requirements of modern electronic devices for high frequency, high power density and low loss, and the mechanical strength and thermal conductivity of low-temperature co-fired ceramics are insufficient.
A medium-temperature co-fired electrode slurry is used, and copper powder and titanium nitride powder are introduced to form a highly interconnected conductive network. The titanium nitride powder is combined with the titanium nitride powder to suppress copper loss, thereby achieving dense co-firing and excellent conductivity.
Achieving dense co-firing in the mid-temperature range yields superior conductivity compared to traditional high-temperature co-fired electrodes, reducing resistance, improving signal transmission efficiency, and combining mechanical strength and thermal stability.
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Figure CN122127168A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electronic materials technology, and in particular to a medium-temperature co-fired electrode slurry, its preparation method, and a metal electrode. Background Technology
[0002] In the field of electronic packaging, high-temperature co-fired ceramic (HTCC) technology is widely used due to its excellent mechanical strength and thermal stability. However, HTCC technology has two inherent challenges: first, its sintering temperature is usually above 1500℃, resulting in huge energy consumption and extremely high equipment requirements; second, due to such high temperatures, only high-melting-point metals such as tungsten and molybdenum can be used as conductive phases, but the conductivity of these metals is much lower than that of good conductors such as silver and copper, resulting in high resistance and large signal transmission loss in the final circuit, making it difficult to meet the urgent needs of modern electronic devices such as 5G communication, high-performance computing, and high-power modules for high frequency, high power density, and low loss.
[0003] To lower the co-firing temperature, low-temperature co-fired ceramic (LTCC) technology has emerged, with sintering temperatures reduced to 850℃~900℃, allowing the use of highly conductive metals such as silver and gold. However, the thermal conductivity and mechanical strength of the LTCC substrate itself are generally lower than those of HTCC materials. Therefore, there is an urgent need to develop an electrode material system that combines the advantages of medium-temperature co-firing and high conductivity to achieve a better balance between performance and cost. Summary of the Invention
[0004] Based on this, the purpose of the present invention is to provide a medium-temperature co-fired electrode slurry, its preparation method and metal electrode. The slurry can achieve dense co-firing in the medium-temperature sintering temperature range (1200℃~1500℃) and can obtain better conductivity than traditional HTCC tungsten or molybdenum electrodes.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] This invention provides a medium-temperature co-fired electrode slurry, which is prepared from the following components by mass percentage: 60%~85% functional phase powder, 14%~25% organic carrier, 0.5%~10.0% binder phase, 0.1%~2.0% titanium nitride powder, and 0~5.0% additives; wherein the functional phase powder includes tungsten powder and copper powder.
[0007] The medium-temperature co-fired electrode slurry provided by this invention uses functional phase powder as the conductive phase, replacing the pure tungsten or pure molybdenum used in traditional HTCC. By introducing copper components, dense co-firing can be achieved in the medium-temperature sintering temperature range (1200℃~1500℃), forming a highly interconnected conductive network, thereby obtaining better conductivity than traditional HTCC tungsten or molybdenum electrodes. At the same time, the introduction of titanium nitride powder inhibits the loss of copper elements during the medium-temperature co-firing process, thereby ensuring the conductivity of the conductive film layer.
[0008] As a further improvement of the above-mentioned solution of the present invention, the functional phase powder is composed of tungsten powder and copper powder, and the mass ratio of tungsten powder to copper powder is 1~9:1; the tungsten powder and copper powder are submicron-sized spherical or near-spherical powders with a D50 of 0.5~5.0μm. The preparation method of the functional phase powder is as follows: Tungsten powder, grinding slurry, and grinding media are placed in a grinding container and ground. The particle size of the tungsten powder after grinding is measured using a laser particle size analyzer. Then, by optimizing the grinding formula ratio and grinding time, the particle size of the tungsten powder is controlled within the desired range (preferably 1 μm) to obtain the target tungsten powder. Copper powder, grinding slurry, and grinding media are placed in a grinding container and ground. The particle size of the copper powder after grinding is measured using a laser particle size analyzer. Then, by optimizing the grinding formula ratio and grinding time, the particle size of the copper powder is controlled within the desired range (preferably 1 μm) to obtain the target copper powder. The target tungsten powder, target copper powder, grinding slurry, and grinding media are placed in a grinding container and ground and mixed for a short time. Then, the mixture is sieved and dried to obtain the functional phase powder. Controlling the tungsten-copper ratio in the functional phase powder can achieve an optimal balance between conductivity, strength / stability, and thermal expansion matching.
[0009] As a further improvement to the above-described scheme of the present invention, the organic carrier comprises a polymer and an organic solvent. The polymer is selected from at least one of ethyl cellulose and polyacrylic acid resin, and the organic solvent is selected from at least one of cyclohexanone, toluene, terpineol, and dibutyl phthalate. The organic carrier is prepared by placing the organic solvent in a mixing container and mixing thoroughly by mechanical stirring; weighing the polymer into the organic solvent and stirring thoroughly by mechanical stirring until a transparent solution or colloid without obvious insoluble substances is formed, which is the organic carrier. In the organic carrier, the concentration of the polymer is 5wt%~50wt%; preferably 10wt%.
[0010] As a further improvement to the above-described scheme of the present invention, the binder phase is selected from at least one of oxides and glasses; the oxide is at least one of metal oxides and non-metal oxides; the glass is a B-Si-Al-Zn system glass, and the glass contains the following components in mass percentage: Bi2O3 30%~50%, B2O3 20%~35%, SiO2 10%~20%, Al2O3 5%~10%, ZnO 2%~8%. The binder phase is prepared by: thoroughly mixing one or more oxides and / or glasses by mechanical stirring, and then grinding them to form a powder with a certain particle size distribution (0.5μm~15μm, preferably 1μm), thus obtaining the binder phase.
[0011] As a further improvement to the above-described solution of the present invention, the method for preparing the titanium nitride powder is as follows: titanium nitride powder, grinding slurry, and grinding media are placed in a grinding container for grinding treatment, and the particle size of the treated titanium nitride powder is tested using a laser particle size analyzer to control the particle size of the titanium nitride powder within the desired range. Preferably, the particle size of titanium nitride is 0.5 μm.
[0012] As a further improvement to the above-mentioned scheme of the present invention, the additive is selected from at least one of fish oil, polyether-modified polydimethylsiloxane, and polyester-type superdispersant.
[0013] As a further improvement to the above-mentioned scheme of the present invention, the sintering temperature of the medium-temperature co-fired electrode slurry is 1200℃~1500℃, and the sintering atmosphere is hydrogen. In the sintering cooling stage of the present invention, the slurry is first cooled to 400℃~500℃ and held for 2-3 hours, and then naturally cooled to room temperature; this causes the titanium-copper solid solution generated by the degradation of titanium nitride to precipitate intermetallic compounds, thereby improving conductivity.
[0014] The present invention also provides a method for preparing the intermediate-temperature co-fired electrode slurry as described above, which includes the following steps: mixing functional phase powder, organic carrier, binder phase, titanium nitride powder and additives in proportion to form an initial slurry mixing system; and rolling the initial slurry mixing system to form the intermediate-temperature co-fired electrode slurry.
[0015] The present invention also provides a metal electrode prepared using the medium-temperature co-fired electrode slurry as described above.
[0016] As a further improvement to the above-mentioned solution of the present invention, the preparation method includes the following steps: forming a circuit pattern with a line resolution ≥100μm on a green ceramic sheet by means of screen printing or additive manufacturing of the medium-temperature co-fired electrode slurry, and then sintering to obtain a metal electrode.
[0017] As a further improvement to the above-mentioned scheme of the present invention, the sintering is carried out under a hydrogen atmosphere, first by heating to 500℃~600℃ and holding for 2~3 hours, then heating to 1200℃~1500℃ and holding for 2~3 hours, then cooling to 400℃~500℃ and holding for 2~3 hours, and then naturally cooling to room temperature. Since the degradation of titanium nitride into titanium reduces conductivity, the present invention holds at 400℃~500℃ during cooling, allowing intermetallic compounds such as Cu4Ti to precipitate from the high-temperature solid solution of copper and titanium, thereby reducing the electron scattering effect of titanium and improving conductivity.
[0018] Compared with the prior art, the present invention has the following beneficial effects: The medium-temperature co-fired electrode slurry proposed in this invention significantly improves conductivity by introducing copper, while maintaining thermal stability and strength using a tungsten framework, laying the material basis for achieving high conductivity at medium temperatures. At the same time, titanium nitride is introduced to achieve a copper loss prevention mechanism. Titanium nitride ensures that copper is effectively retained in the electrode through multiple mechanisms such as physically blocking diffusion paths and pinning grain boundaries to prevent copper oxidation.
[0019] The preparation method of this invention is applicable to medium-temperature co-fired electrode pastes in multilayer co-fired material systems to enhance conductivity. It utilizes one or more functional phase powders of varying particle sizes, blended with a binder phase, an organic carrier, titanium nitride powder, and additives to form the medium-temperature co-fired electrode paste. The functional phase powder, organic carrier, binder phase, titanium nitride powder, and additives are uniformly mixed using stirring. The functional phase powder is densified by high-temperature sintering to form a conductive film layer, thereby realizing the circuit function. The organic carrier utilizes a polymer to provide printability for the electrode paste. The binder phase enhances the bonding force between the metal electrode and the ceramic substrate through oxides and glass, ensuring that the conductive metal film layer does not detach after co-firing. The titanium nitride powder inhibits the loss of copper elements during co-firing, thus ensuring the conductivity of the conductive film layer. The additives optimize the printability of the electrode paste. Attached Figure Description
[0020] Figure 1 This is a photograph of the medium-temperature co-fired electrode slurry prepared in Example 1 of the present invention. Figure 2 This is a schematic diagram of the multilayer ceramic substrate structure obtained in Embodiment 1 of the present invention. Detailed Implementation
[0021] To facilitate understanding of the present invention, a more comprehensive description will be given below with reference to specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of the present invention.
[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
[0023] Example 1 This embodiment proposes a medium-temperature co-fired electrode slurry, the preparation method of which includes the following five steps (1)-(5): (1) Preparation of functional phase powder: Weigh 100g of tungsten powder, 200g of anhydrous ethanol, and 100g of grinding balls and add them to a ball mill jar. Process the mixture at a ball milling speed of 400r / min for 2 hours, then filter and dry to obtain target tungsten powder with a particle size of 1μm. Weigh 100g of copper powder, 200g of anhydrous ethanol, and 100g of grinding balls and add them to a ball mill jar. Process the mixture at a ball milling speed of 400r / min for 2 hours, then filter and dry to obtain target copper powder with a particle size of 1μm. Weigh 72g of target tungsten powder, 8g of target copper powder, 160g of anhydrous ethanol and 80g of grinding balls and add them to a ball mill jar. Process the powder at a ball milling speed of 100r / min for 15min, then filter and dry to obtain functional phase powder with a particle size of 1μm.
[0024] (2) Preparation of binder phase: Weigh 84g of bismuth oxide, 40g of boron oxide, 40g of silicon dioxide, 20g of aluminum oxide, 16g of zinc oxide, 400g of anhydrous ethanol and 200g of grinding balls and add them to a ball mill jar. Process the mixture at a ball milling speed of 100r / min for 1h, then filter and dry to obtain a glass mixture system. 150g of glass mixture was placed in a platinum crucible and melted at 1450℃, then quenched in water to make glass; 100g of glass, 200g of anhydrous ethanol and 100g of grinding balls were added to a ball mill jar and processed at a ball milling speed of 400r / min for 2h, then filtered and dried to obtain glass powder. Weigh 15g of alumina, 55g of silica, 5g of zirconium oxide, 35g of glass powder, 200g of anhydrous ethanol and 100g of grinding balls and add them to a ball mill jar. Process the mixture at a ball milling speed of 400r / min for 2 hours, then filter and dry to obtain a powdery binder phase with a particle size of 1μm.
[0025] (3) Titanium nitride powder treatment: Weigh 100g of titanium nitride, 200g of anhydrous ethanol and 100g of grinding balls and add them to the ball mill jar. Treat the powder at a ball milling speed of 400r / min for 4h, then filter and dry to obtain titanium nitride powder with a particle size of 0.5μm.
[0026] (4) Preparation of organic carrier: Weigh 100g of cyclohexanone and 200g of terpineol and place them in a beaker. Stir mechanically for 1h to obtain organic solvent. Weigh 6g of ethyl cellulose and 4g of polyacrylic acid resin and add them to 90g of organic solvent. Heat and stir at 65℃ for 4h to fully dissolve and obtain organic carrier.
[0027] (5) Preparation of intermediate-temperature co-fired electrode slurry: Weigh 75g of functional phase powder, 15.5g of organic carrier, 8g of binder phase, 1g of titanium nitride powder and 0.5g of fish oil, and mechanically mix them at 1000r / min for 10min to obtain the initial intermediate-temperature co-fired electrode slurry; place the initial intermediate-temperature co-fired electrode slurry in a three-roll mill and roll it for 30min to obtain the intermediate-temperature co-fired electrode slurry, as shown below. Figure 1 As shown.
[0028] The circuit pattern of the medium-temperature co-fired electrode paste prepared in this embodiment was screen-printed onto a green ceramic sheet. The green ceramic sheet with the pattern was then dried, stacked, and pressed to obtain the sample to be fired. The sample was placed in an atmosphere sintering furnace, and high-purity hydrogen was introduced. The temperature was increased from room temperature to 550°C at 2°C / min and held for 2 hours, then increased to 1400°C at 2°C / min and held for 2 hours. The temperature was then decreased to 500°C at 2°C / min and held for 2 hours, followed by natural cooling to room temperature to obtain a multilayer metal electrode, such as... Figure 2 As shown. After testing, the sheet resistance of the multilayer metal electrode fabricated in this embodiment is 8.1 mΩ / .
[0029] Example 2 This embodiment proposes a medium-temperature co-fired electrode slurry, the preparation method of which includes the following five steps (1)-(5): (1) Preparation of functional phase powder: Weigh 100g of tungsten powder, 150g of anhydrous ethanol and 100g of grinding balls and add them to a ball mill jar. Process the mixture at a ball milling speed of 400r / min for 2 hours, then filter and dry to obtain target tungsten powder with a particle size of 1μm. Weigh 100g of copper powder, 150g of anhydrous ethanol and 100g of grinding balls and add them to a ball mill jar. Process the mixture at a ball milling speed of 400r / min for 2 hours, then filter and dry to obtain target copper powder with a particle size of 1μm. Weigh 64g of target tungsten powder, 16g of target copper powder, 160g of anhydrous ethanol and 80g of grinding balls and add them to a ball mill jar. Process the powder at a ball milling speed of 100r / min for 15min, then filter and dry to obtain functional phase powder with a particle size of 1μm.
[0030] (2) Preparation of binder phase: Weigh 96g bismuth oxide, 44g boron oxide, 28g silicon dioxide, 16g aluminum oxide, 16g zinc oxide, 400g anhydrous ethanol and 200g grinding balls and add them to a ball mill jar. Process the mixture at a ball milling speed of 100r / min for 1h, then filter and dry to obtain a glass mixture system. 150g of glass mixture was placed in a platinum crucible and melted at 1400℃, then quenched in water to make glass; 100g of glass, 200g of anhydrous ethanol and 100g of grinding balls were added to a ball mill jar and processed at a ball milling speed of 400r / min for 2h, then filtered and dried to obtain glass powder. Weigh 20g of alumina, 35g of silica, 45g of glass powder, 200g of anhydrous ethanol and 100g of grinding balls and add them to a ball mill jar. Process the mixture at a ball milling speed of 400r / min for 2h, then filter and dry to obtain a powdery binder phase with a particle size of 1μm.
[0031] (3) Titanium nitride powder treatment: Weigh 100g of titanium nitride, 200g of anhydrous ethanol, and 100g of grinding balls and add them to a ball mill jar. Process the mixture at a ball milling speed of 600r / min for 4 hours, then filter and dry to obtain titanium nitride powder with a particle size of 0.5μm.
[0032] (4) Preparation of organic carriers: Weigh 100g toluene, 100g cyclohexanone, and 200g terpineol and place them in a beaker. Stir mechanically for 1 hour to obtain an organic solvent. Weigh 6g ethyl cellulose and 4g polyacrylic acid resin and add them to 90g of the organic solvent. Heat and stir at 65°C for 4 hours to fully dissolve the organic solvent and obtain an organic carrier.
[0033] (5) Preparation of medium-temperature co-fired electrode slurry: Weigh 80g of functional phase powder, 15g of organic carrier, 3g of binder phase, 1.5g of titanium nitride powder and 0.5g of polyester-type superdispersant, and mechanically mix them at 1000r / min for 10min to obtain the initial medium-temperature co-fired electrode slurry; place the initial medium-temperature co-fired electrode slurry in a three-roll mill and roll it for 30min to obtain the medium-temperature co-fired electrode slurry.
[0034] The circuit pattern of the medium-temperature co-fired electrode paste prepared in this embodiment was screen-printed onto a green ceramic sheet. The patterned green ceramic sheet was then dried, stacked, and pressed to obtain the sample to be fired. The sample was placed in an atmosphere sintering furnace, and high-purity hydrogen was introduced. The temperature was increased from room temperature to 550°C at 2°C / min and held for 2 hours, then increased to 1300°C at 2°C / min and held for 2 hours, then decreased to 500°C at 2°C / min and held for 2 hours, followed by natural cooling to room temperature to obtain a multilayer metal electrode. Testing showed that the sheet resistance of the multilayer metal electrode prepared in this embodiment was 6.9 mΩ / min. .
[0035] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0036] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.
Claims
1. A medium-temperature co-fired electrode slurry, characterized in that, It is prepared from the following components in mass percentage: 60%~85% functional phase powder, 14%~25% organic carrier, 0.5%~10.0% binder phase, 0.1%~2.0% titanium nitride powder, and 0~5.0% additives; the functional phase powder includes tungsten powder and copper powder.
2. The medium-temperature co-fired electrode slurry according to claim 1, characterized in that, The functional phase powder is composed of a mixture of tungsten powder and copper powder, with a mass ratio of tungsten powder to copper powder of 1 to 9:1; the tungsten powder and copper powder are submicron-sized spherical or near-spherical powders with a D50 of 0.5 to 5.0 μm.
3. The medium-temperature co-fired electrode slurry according to claim 1, characterized in that, The organic carrier comprises a polymer and an organic solvent, wherein the polymer is selected from at least one of ethyl cellulose and polyacrylic acid resin, and the organic solvent is selected from at least one of cyclohexanone, toluene, terpineol, and dibutyl phthalate.
4. The medium-temperature co-fired electrode slurry according to claim 1, characterized in that, The binder phase is selected from at least one of oxides and glasses; the oxide is at least one of metal oxides and non-metal oxides; the glass is a B-Si-Al-Zn system glass, and the glass contains the following components in mass percentage: Bi2O3 30%~50%, B2O3 20%~35%, SiO2 10%~20%, Al2O3 5%~10%, ZnO 2%~8%.
5. The medium-temperature co-fired electrode slurry according to claim 1, characterized in that, The additive is selected from at least one of fish oil, polyether-modified polydimethylsiloxane, and polyester-type superdispersant.
6. The medium-temperature co-fired electrode slurry according to claim 1, characterized in that, The sintering temperature of the medium-temperature co-fired electrode slurry is 1200℃~1500℃, and the sintering atmosphere is hydrogen.
7. A method for preparing a medium-temperature co-fired electrode slurry as described in any one of claims 1-6, characterized in that, It includes the following steps: The functional phase powder, organic carrier, binder phase, titanium nitride powder, and additives are mixed evenly in proportion to form an initial slurry mixing system; the initial slurry mixing system is rolled to form a medium-temperature co-fired electrode slurry.
8. A metal electrode, characterized in that, It is prepared using the medium-temperature co-fired electrode slurry as described in any one of claims 1 to 6.
9. The metal electrode according to claim 8, characterized in that, The preparation method includes the following steps: the medium-temperature co-fired electrode slurry is used to form a circuit pattern on a green ceramic sheet by screen printing or additive manufacturing, and then sintered to obtain a metal electrode.
10. The metal electrode according to claim 9, characterized in that, The sintering process involves heating the temperature to 500℃~600℃ and holding it for 2~3 hours in a hydrogen atmosphere, then heating it to 1200℃~1500℃ and holding it for 2~3 hours, then cooling it to 400℃~500℃ and holding it for 2~3 hours, and finally allowing it to cool naturally to room temperature.