Rolling printing electrode silver paste and its preparation method and application

Abstract

The present invention relates to the technical field of conductive silver paste, and in particular to a silver paste for rolling-printed electrodes, a preparation method thereof, and applications thereof. A silver paste for rolling-printed electrodes comprises micron-sized spherical silver powder, micron-sized flaky silver powder, nano-sized flaky silver powder, an organic carrier, and glass powder; the organic carrier comprises a polymer resin composed of nitrocellulose, polyvinyl butyral, and polyimide resin, and the glass powder is a mixture of glass powder Z having a sintering temperature of 600-700°C and glass powder N having a sintering temperature of 650-750°C. The silver paste for rolling-printed electrodes provided in the present application can not only effectively improve the printing performance of electrodes, but also improve the adhesion of electrodes, thereby ensuring the stability and reliability of the electrodes.

Description

Technical Field

[0001] The present invention relates to the technical field of conductive silver paste, and in particular to a rolling printing electrode silver paste, a preparation method and an application thereof. Background Art

[0002] Roll-to-roll printed electrode silver paste, a key material in electronic component manufacturing, plays a key role in the production of ferrite bead array inductors. As a widely used component in electronic devices, ferrite bead arrays are widely used in DC isolation, coupling, bypassing, filtering, tuning circuits, energy conversion, and control circuits. These applications include general electronic circuits such as laptops, motherboards, mobile phones, and digital cameras, as well as high-voltage circuits and LCD backlight converter circuits.

[0003] As electronic products continue to miniaturize, the size of magnetic bead arrays continues to shrink, and the dimensional requirements for roll-to-roll printed electrodes are becoming increasingly precise. Consequently, the electrode lines created by roll-to-roll printing often expand in width, leading to fishbone defects. These defects exceed the standard size and pose a risk of short circuits later in the process. Furthermore, as electrode lines become thinner, the adhesion requirements for the silver paste-formed electrodes are also increasing.

[0004] Therefore, as electronic components are becoming increasingly miniaturized and refined, how to ensure the rolling printing quality of electrode silver paste and improve the adhesion of electrodes has become a technical problem that needs to be solved urgently in the field of electronic component manufacturing. Summary of the Invention

[0005] To ensure the quality of roll-printed electrode silver paste and improve electrode adhesion amidst the trend of increasingly miniaturized electronic components, this application provides a roll-printed electrode silver paste, its preparation method, and its application. The roll-printed electrode silver paste provided in this application not only effectively controls electrode line width and avoids the generation of fishbone defects, but also improves electrode adhesion, ensuring electrode stability and reliability.

[0006] In the first aspect, the present application provides a rolling printing electrode silver paste adopting the following technical solution:

[0007] A silver paste for rolling-printed electrodes comprises the following raw materials in percentage by mass: 35%-40% micron-sized spherical silver powder, 25%-35% micron-sized flaky silver powder, 10%-15% nano-sized flaky silver powder, 10%-25% organic carrier, and 3%-5% glass powder;

[0008] The organic carrier is prepared by mixing a polymer resin and an organic solvent in a mass ratio of (1-3): (7-9);

[0009] The polymer resin is prepared by mixing nitrocellulose, polyvinyl butyral and polyimide resin in a mass ratio of (1-2): (1-2): (0.5-1);

[0010] The glass powder is formed by mixing glass powder Z with a sintering temperature of 600-700° C. and glass powder N with a sintering temperature of 650-750° C. in a mass ratio of 1:1.

[0011] In the above technical solution, the present application not only improves the conductivity of the electrode by combining micron-sized spherical silver powder and micron-sized flaky silver powder, but also enhances the mechanical strength of the electrode through the filling effect of the spherical silver powder. The present application further adds nano-sized flaky silver powder, because the nano-sized flaky silver powder has a larger specific surface area and can form more contact points with the substrate, thereby enhancing the adhesion between the silver paste and the substrate, thereby further improving the conductivity and adhesion of the electrode. At the same time, the present application adopts a polymer resin prepared by nitrocellulose, polyvinyl butyral and polyimide resin in a specific proportion, through the solubility and adhesion of nitrocellulose, through the mechanical strength and heat resistance of polyvinyl butyral, through the high temperature resistance and chemical stability of the polyimide resin, through these characteristics work together, so that the silver paste has better adhesion and stability during the printing process, thereby ensuring the reliability of the electrode. In addition, by mixing glass powder Z with a sintering temperature of 600-700°C and glass powder N with a sintering temperature of 650-750°C, the glass powder has good sintering performance at different temperatures, thereby providing a better bonding effect during the electrode formation process, which not only helps to improve the mechanical strength of the electrode, but also improves the heat resistance of the electrode to a certain extent, thereby further enhancing the adhesion and stability of the electrode. Through the above-mentioned optimization of the roll-printed electrode silver paste, the present application can effectively control the electrode line width, avoid the generation of fishbone defects, and significantly improve the adhesion of the electrode.

[0012] Preferably, the mass ratio of the nitrocellulose, polyvinyl butyral and polyimide resin is 2:1:1.

[0013] In the above technical solution, this application optimizes the mass ratio of nitrocellulose, polyvinyl butyral, and polyimide resin to 2:1:1, resulting in better adhesion and stability of the silver paste during the printing process. Nitrocellulose provides good solubility and adhesion, allowing the silver paste to adhere better to the substrate surface; polyvinyl butyral provides the necessary mechanical strength and heat resistance, ensuring that the silver paste will not deform or damage during high-temperature sintering; and the high-temperature resistance and chemical stability of the polyimide resin further enhance the heat resistance and long-term stability of the silver paste.

[0014] Preferably, the organic solvent is one or more of terpineol, ethylene glycol ethyl ether acetate, ethylene glycol butyl ether acetate, turpentine, and cyclohexanone.

[0015] In the above technical solution, the present application selects one or more of terpineol, ethylene glycol ethyl ether acetate, ethylene glycol butyl ether acetate, turpentine, and cyclohexanone as organic solvents. These solvents have good solubility and volatility, which can ensure that the polymer resin can be fully dissolved and evenly mixed during the preparation of the organic carrier. At the same time, these solvents can evaporate quickly during the subsequent printing process, reducing the impact on the performance of the electrode silver paste, thereby ensuring the stability and reliability of the electrode silver paste during the printing process.

[0016] Preferably, based on the mass fraction of the glass powder Z, the glass powder Z includes 20-30 parts of zinc oxide, 10-20 parts of sodium oxide, 10-20 parts of bismuth trioxide, 15-30 parts of silicon dioxide, 10-20 parts of boron oxide, 5-20 parts of aluminum oxide, 10-20 parts of barium oxide, 1-6 parts of titanium dioxide, 2-6 parts of copper oxide, and 1-10 parts of nickel oxide.

[0017] Preferably, based on the mass fraction of the glass powder N, the glass powder N includes 10-20 parts of zinc oxide, 20-30 parts of sodium oxide, 10-20 parts of bismuth trioxide, 15-30 parts of silicon dioxide, 10-20 parts of boron oxide, 5-20 parts of aluminum oxide, 10-20 parts of barium oxide, 1-6 parts of titanium dioxide, 2-6 parts of copper oxide, and 1-10 parts of nickel oxide.

[0018] In the above technical solution, the present application specifically defines the composition and ratio of glass powder Z and glass powder N, and fine-tunes the amount of glass powder Z and glass powder N so that glass powder Z and glass powder N can form a uniform glass phase during the sintering process to adapt to a higher sintering temperature range, thereby ensuring the stability of the electrode at different temperatures. The addition of zinc oxide, sodium oxide and bismuth trioxide helps to lower the melting point of the glass, so that the glass powder can still maintain good sintering performance at higher temperatures, thereby ensuring the stability of the electrode at high temperatures. Silicon dioxide, boron oxide and aluminum oxide provide good chemical stability and mechanical strength, ensuring the long-term reliability of the electrode. The addition of barium oxide, titanium dioxide, copper oxide and nickel oxide further optimizes the electrical properties and corrosion resistance of the glass powder, thereby improving the overall performance of the electrode.

[0019] Preferably, the particle size of the glass powder Z is 0.5-2 μm, and the particle size of the glass powder N is 0.5-2 μm.

[0020] In the above technical solution, this application ensures the uniform distribution of glass powder in the electrode by limiting the particle size of glass powder Z and glass powder N to 0.5-2μm, thereby forming a uniform glass phase during the sintering process, effectively avoiding the uneven electrode surface or internal stress concentration problems caused by excessively large glass powder particle size. At the same time, the uniform glass phase can improve the mechanical strength and heat resistance of the electrode, ensuring that the electrode will not crack or deform during high-temperature sintering, thereby ensuring the long-term reliability of the electrode.

[0021] Preferably, the particle size of the micron-sized spherical silver powder is 0.6-1 μm, the particle size of the micron-sized flaky silver powder is 1.5-3.5 μm, and the particle size of the nano-sized flaky silver powder is 0.01-0.1 μm.

[0022] In the above technical solution, the present application has carefully designed the particle size distribution of micron-sized spherical silver powder, micron-sized flake silver powder and nano-sized flake silver powder to ensure that the silver powder can be evenly distributed during the printing process, thereby reducing the problem of electrode line width expansion.

[0023] In a second aspect, the present application provides a method for preparing a roll-printed electrode silver paste using the following technical solution:

[0024] A method for preparing a rolling printing electrode silver paste comprises the following steps:

[0025] Step 1: First, mix the organic solvent and the polymer resin evenly to prepare an organic carrier;

[0026] Step 2: Add the remaining raw materials to the organic carrier and stir under vacuum until the mixture is uniform;

[0027] Step 3: Grind the slurry obtained in step 2 to a fineness of less than 7.5 μm, filter, and prepare a silver paste for rolling printing electrodes.

[0028] In the above technical solution, the present application provides a simple and effective process for preparing the rolling-printed electrode silver paste, which ensures the uniformity and stability of the rolling-printed electrode silver paste.

[0029] In a third aspect, the present application provides an application of a rolling printing electrode silver paste using the following technical solution:

[0030] The invention discloses an application of a rolling printing electrode silver paste, which is to use the rolling printing electrode silver paste in printing magnetic bead electrodes.

[0031] In the above technical solution, the roll-printed electrode silver paste of this application has excellent printing performance and high adhesion, and is particularly suitable for the roll-printing of magnetic bead electrodes. It can effectively avoid the generation of fishbone defects, ensure the accuracy of electrode dimensions, and reduce the risk of short circuits in the later stage. In addition, the roll-printed electrode silver paste of this application is also suitable for other electronic component manufacturing fields that require high-precision and high-adhesion electrodes.

[0032] In summary, this application includes at least one of the following beneficial technical effects:

[0033] 1. The present application combines micron-sized spherical silver powder, micron-sized flaky silver powder, and nano-sized flaky silver powder, adopts a polymer resin prepared from nitrocellulose, polyvinyl butyral, and polyimide resin, and mixes glass powder Z with a sintering temperature of 600-700°C and glass powder N with a sintering temperature of 650-750°C. By optimizing the glass powder composition and particle size, the electrode line width is effectively controlled, the generation of fishbone defects is avoided, and the adhesion of the electrode is significantly improved.

[0034] 2. The rolling printing electrode silver paste of this application is suitable for the rolling printing of magnetic bead electrodes, effectively avoiding the generation of fishbone defects, ensuring the accuracy of electrode size, effectively improving electrode adhesion, and reducing the risk of later short circuits. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a picture of the printed electrode of the roll-printed electrode silver paste of Example 1.

[0036] Figure 2 This is a picture of the printed electrode of the roll-printed electrode silver paste of Example 2.

[0037] Figure 3 This is a picture of the printed electrode of the rolling printed electrode silver paste of Example 3.

[0038] Figure 4 This is a picture of the printed electrode of the rolling printed electrode silver paste of comparative example 1.

[0039] Figure 5 This is a picture of the printed electrode of the rolling printed electrode silver paste of comparative example 2.

[0040] Figure 6 This is a picture of the printed electrode of the rolling printed electrode silver paste of comparative example 3.

[0041] Figure 7 This is a picture of the printed electrode of the rolling printed electrode silver paste of comparative example 4.

[0042] Figure 8 This is a picture of the printed electrode of the rolling printed electrode silver paste of comparative example 5.

[0043] Figure 9 This is a picture of the printed electrode of the rolling printed electrode silver paste of Comparative Example 6. DETAILED DESCRIPTION

[0044] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0045] Example 1

[0046] A rolling printing electrode silver paste comprises micron-sized spherical silver powder, micron-sized flaky silver powder, nanometer-sized flaky silver powder, an organic carrier and glass powder.

[0047] Among them, the micron-sized spherical silver powder is homemade, with a particle size between 0.6-1μm.

[0048] Among them, the micron-sized flaky silver powder is homemade, with a particle size between 1.5-3.5μm.

[0049] Among them, the nano-scale flaky silver powder is homemade, with a particle size between 0.01-0.1μm.

[0050] Among them, the organic carrier is prepared from polymer resin and organic solvent.

[0051] Among them, the polymer resin is composed of nitrocellulose, polyvinyl butyral and polyimide resin.

[0052] The organic solvent is a mixture of terpineol and cyclohexanone in a mass ratio of 1:1.

[0053] Among them, the glass powder Z is homemade, and the particle size is between 0.5-2 μm.

[0054] Among them, the glass powder N is homemade, and the particle size is between 0.5-2 μm.

[0055] The method for preparing the rolling printing electrode silver paste comprises the following steps:

[0056] Step 1: First, completely dissolve the polymer resin in the organic solvent at 60-70°C, and stir until the mixture is uniform to prepare an organic carrier.

[0057] Step 2: Add the remaining raw materials to the organic carrier and stir under vacuum until the mixture is uniform.

[0058] Step 3: Grind the slurry obtained in step 2 with a three-roll mill to a fineness of less than 7.5 μm, filter, and prepare a silver paste for rolling printing electrodes.

[0059] Example 2

[0060] A rolling printing electrode silver paste, which is different from Example 1 in that the amounts of various raw materials used are inconsistent.

[0061] Example 3

[0062] A rolling printing electrode silver paste, which is different from Example 1 in that the amounts of various raw materials used are inconsistent.

[0063] The amounts of the micron-sized spherical silver powder, micron-sized flaky silver powder, nano-sized flaky silver powder, polymer resin, organic solvent, glass powder Z, and glass powder N in Examples 1-3 are shown in Table 1.

[0064] Table 1:

[0065]

[0066] The raw material ratios of the polymer resins used in Examples 1-3 are shown in Table 2.

[0067] Table 2:

[0068]

[0069]

[0070] The raw material ratios of the glass powder Z used in Examples 1-3 are shown in Table 3.

[0071] Table 3:

[0072]

[0073] The raw material ratios of the glass powder N used in Examples 1-3 are shown in Table 4.

[0074] Table 4:

[0075]

[0076]

[0077] Comparative Example 1

[0078] A silver paste for rolling-printed electrodes, which differs from Example 1 in that an equal amount of nitrocellulose is replaced by ethyl cellulose.

[0079] Comparative Example 2

[0080] A silver paste for rolling-printed electrodes is provided, which differs from Example 1 in that an equal amount of polyvinyl butyral is replaced by acrylic resin.

[0081] Comparative Example 3

[0082] A roll-printed electrode silver paste is provided, which differs from Example 1 in that an equal amount of polyimide resin is replaced by acrylic resin.

[0083] Comparative Example 4

[0084] A silver paste for rolling-printed electrodes, which differs from Example 1 in that an equal amount of nano-scale flaky silver powder is replaced with micron-scale flaky silver powder.

[0085] Comparative Example 5

[0086] A rolling printing electrode silver paste, which is different from Example 1 in that glass powder N is replaced by glass powder Z in equal amounts.

[0087] Comparative Example 6

[0088] A rolling printing electrode silver paste, which is different from Example 1 in that the glass powder Z is replaced by glass powder N in equal amounts.

[0089] Performance testing:

[0090] Sample: Roll-printed electrode silver paste of Examples 1-3 and Comparative Examples 1-6.

[0091] The sample was prepared according to the conventional preparation process of magnetic bead array inductor to obtain 2012 magnetic bead array inductor, and the printed pattern and adhesion of the magnetic bead array inductor were tested.

[0092] Among them, the printed graphics are shown in Figure 1-9 .

[0093] Among them, the adhesion test uses a tensile tester. The test method is: visual inspection at the minimum tension for 30 seconds. The inspection end is required to be free of damage and fall off. The end tension standard of the CBA magnetic bead array is: 2012 ≥ 0.3 kgf. When the tension without damage and fall off reaches the above standard, it is considered qualified. The test results are shown in Table 5.

[0094] Table 5:

[0095]

[0096]

[0097] Combine Figure 1-9 Observation and analysis, Figure 1-3 、 Figure 8-9 The printed electrode pictures have qualified appearance, Figure 4 The printed electrodes in the printed electrode pictures are outward-expanding, with exposed corners and steps, and the appearance is unqualified. Figure 5 The magnet in the printed electrode picture is silver-sticky and the appearance is unqualified. Figure 6 The magnet in the printed electrode picture is silver-sticky and the appearance is unqualified. Figure 7 The printed electrodes in the printed electrode picture are outwardly expanded, with stepped edges and corners, and the appearance is unqualified.

[0098] Specifically combining the analysis of the test data of the rolling printing electrode silver paste of Examples 1-3 and Comparative Examples 1-6, it can be seen that Examples 1-3 have good printing performance and adhesion, Comparative Examples 1-4 have good adhesion, and Comparative Examples 5-6 have good printing performance.

[0099] Specifically analyzed in combination with Example 1 and Comparative Examples 1-4, the difference between Comparative Examples 1-4 and Example 1 is that in Comparative Example 1, an equal amount of nitrocellulose is replaced by ethyl cellulose, an equal amount of polyvinyl butyral is replaced by acrylic resin in Comparative Example 2, an equal amount of polyimide resin is replaced by acrylic resin in Comparative Example 3, and an equal amount of nano-scale flaky silver powder is replaced by micron-scale flaky silver powder in Comparative Example 4. Through these comparisons, the present application can find that the use of nitrocellulose, polyvinyl butyral, polyimide resin and nano-scale flaky silver powder has a positive effect on the printing performance and adhesion of the rolling printed electrode silver paste, and can further improve the printing performance and adhesion of the rolling printed electrode silver paste.

[0100] Specifically analyzing in combination with Example 1 and Comparative Examples 5-6, the difference between Comparative Examples 5 and 6 and Example 1 is that glass powder N and glass powder Z are replaced respectively. It can be seen that the combined use of glass powder N and glass powder Z has a certain effect on the adhesion of the rolling printed electrode silver paste. In order to ensure that the rolling printed electrode silver paste of the present application can have good printing performance and adhesion at the same time, it is necessary to add glass powder N and glass powder Z to the rolling printed electrode silver paste at the same time.

[0101] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A silver paste for rolling printed electrodes, characterized in that: The invention comprises the following raw materials in percentage by mass: 35%-40% micron-sized spherical silver powder, 25%-35% micron-sized flaky silver powder, 10%-15% nano-sized flaky silver powder, 10%-25% organic carrier and 3%-5% glass powder; the particle size of the micron-sized spherical silver powder is 0.6-1 μm, the particle size of the micron-sized flaky silver powder is 1.5-3.5 μm, and the particle size of the nano-sized flaky silver powder is 0.01-0.1 μm; The organic carrier is prepared by mixing a polymer resin and an organic solvent in a mass ratio of (1-3): (7-9); the polymer resin is composed of nitrocellulose, polyvinyl butyral and polyimide resin in a mass ratio of 2:1:1, and the organic solvent is a mixture of terpineol and cyclohexanone in a mass ratio of 1:1; The glass powder is formed by mixing glass powder Z with a sintering temperature of 600-700°C and glass powder N with a sintering temperature of 650-750°C in a mass ratio of 1:1; The glass powder Z comprises 20-30 parts of zinc oxide, 10-20 parts of sodium oxide, 10-20 parts of bismuth trioxide, 15-30 parts of silicon dioxide, 10-20 parts of boron oxide, 5-20 parts of aluminum trioxide, 10-20 parts of barium oxide, 1-6 parts of titanium dioxide, 2-6 parts of copper oxide, and 1-10 parts of nickel oxide; the glass powder N comprises 10-20 parts of zinc oxide, 20-30 parts of sodium oxide, 10-20 parts of bismuth trioxide, 15-30 parts of silicon dioxide, 10-20 parts of boron oxide, 5-20 parts of aluminum trioxide, 10-20 parts of barium oxide, 1-6 parts of titanium dioxide, 2-6 parts of copper oxide, and 1-10 parts of nickel oxide; the particle size of the glass powder Z is 0.5-2 μm, and the particle size of the glass powder N is 0.5-2 μm.

2. A method for preparing a rolling printing electrode silver paste as claimed in claim 1, characterized in that: The following steps are involved: Step 1: First, mix the organic solvent and the polymer resin evenly to prepare an organic carrier; Step 2: Add the remaining raw materials to the organic carrier and stir under vacuum until the mixture is uniform; Step 3: Grind the slurry obtained in step 2 to a fineness of less than 7.5µm, filter, and prepare a silver paste for rolling printing electrodes.

3. An application of rolling printing electrode silver paste, characterized in that, The invention discloses an application of rolling printing electrode silver paste in printing magnetic bead electrodes, wherein the rolling printing electrode silver paste is prepared by the rolling printing electrode silver paste according to claim 1 or the rolling printing electrode silver paste prepared by the preparation method of the rolling printing electrode silver paste according to claim 2.

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