Alloy conductive via paste and preparation method and application thereof

Abstract

The application provides an alloy conductive via paste and a preparation method and application thereof, wherein the alloy conductive via paste comprises conductive metal powder and a mixed resin system; the conductive metal powder comprises nano tin powder, submicron copper powder, spherical silver-coated copper powder and tin-bismuth alloy powder; and the mixed resin system comprises a resin bonding agent, a glycerol ether diluent, a BYK dispersant and an acid anhydride curing agent or an imidazole curing agent. The alloy conductive via paste prepared by the application adopts multiple conductive metal powder compounding and lapping and combines with a resin system, so that the paste can more stably and efficiently realize interlayer interconnection of a multilayer board; on the other hand, the paste can replace a traditional copper electroplating process, so that green and environment-friendly production is realized.

Description

Technical Field

[0001] This invention relates to the field of electronic technology, and in particular to an alloy-type conductive plugging slurry, its preparation method, and its application. Background Technology

[0002] With the rapid development of microelectronics technology, the integration and assembly density of electronic products are constantly increasing, and they are becoming more multifunctional and miniaturized. As the carrier of electronic components, PCB circuit boards are facing increasingly higher integration density and power consumption requirements. PCB circuit boards achieve interlayer electrical interconnection through a large number of microvias, among which interlayer interconnection in multilayer boards is highly favored.

[0003] The commonly used process is still copper electroplating, which involves depositing copper into the inner wall of the hole, then sealing the hole with insulating plugging resin, and finally plating copper on the resin surface to achieve interlayer interconnection. However, this process is complex, involving copper deposit and copper plating, and generates a large amount of wastewater and heavy metal pollution.

[0004] For high-end products, to achieve higher stability, the entire via needs to be conductive, rather than just the via wall. This requires filling the via with conductive paste to achieve interlayer interconnection. While reported methods for preparing conductive via-filling paste can achieve conductivity within the via, they cannot form an alloy layer with the pad surface, thus failing to improve the stability of interlayer interconnection between multilayer boards. Summary of the Invention

[0005] This invention provides an alloy-type conductive plugging slurry, its preparation method, and its application, aiming to solve the technical problems mentioned in the background section of the prior art.

[0006] The contents of this invention are as follows:

[0007] The first aspect of the present invention provides an alloy-type conductive plugging slurry, comprising conductive metal powder and a mixed resin system; the conductive metal powder comprises nano-tin powder, submicron copper powder, spherical silver-coated copper powder and tin-bismuth alloy powder; the mixed resin system comprises a resin binder, a glycerol ether diluent, a BYK dispersant and an anhydride curing agent or an imidazole curing agent.

[0008] In an optional embodiment of the first aspect of the present invention, by volume ratio, the amount of resin adhesive added is 5-10%, the amount of glycerol ether diluent added is 1-3%, the amount of acid anhydride or imidazole curing agent added is 1-3%, the amount of nano tin powder added is 5-8%, the amount of submicron copper powder added is 25-30%, the amount of spherical silver-coated copper powder added is 30-35%, and the amount of tin-bismuth alloy powder added is 20-25%; the amount of BYK dispersant added is 0.5-1 wt% of the total mass of nano tin powder, submicron copper powder, spherical silver-coated copper powder, and tin-bismuth alloy powder.

[0009] In an optional embodiment of the first aspect of the present invention, the resin adhesive includes an epoxy resin adhesive and an acrylic resin adhesive; the glycerol ether diluent includes dodecyl glycidyl ether and castor oil-based glycidyl ether; the BYK dispersant includes BYK-111 dispersant; the acid anhydride curing agent includes methylhexahydrophthalic anhydride curing agent; and the imidazole curing agent includes 2-methylimidazolium curing agent.

[0010] In an optional embodiment of the first aspect of the present invention, the mixed resin system includes an epoxy resin adhesive, dodecyl glycidyl ether, BYK-111 dispersant, and methylhexahydrophthalic anhydride curing agent.

[0011] In an optional embodiment of the first aspect of the present invention, the nano-tin powder has a particle size of 40-60 nm; the submicron copper powder has a particle size of 0.6-0.8 μm; the spherical silver-coated copper powder has a particle size of 2-4 μm; and the tin-bismuth alloy powder has a particle size of 5-9 μm.

[0012] In an optional embodiment of the first aspect of the present invention, the nano-tin powder has a particle size of 50 nm; the submicron copper powder has a particle size of 0.8 μm; the spherical silver-coated copper powder has a particle size of 3 μm; and the tin-bismuth alloy powder has a particle size of 6 μm.

[0013] A second aspect of the present invention provides a method for preparing an alloy-type conductive plugging slurry, comprising:

[0014] The invention provides conductive metal powder and a mixed resin system, wherein the conductive metal powder includes nano-tin powder, submicron copper powder, spherical silver-coated copper powder and tin-bismuth alloy powder, and the mixed resin system includes resin binder, glycerol ether diluent, BYK dispersant and acid anhydride curing agent or imidazole curing agent.

[0015] The conductive metal powder and the mixed resin system are mixed using a mixer to obtain an alloy-type conductive plugging slurry.

[0016] In an optional embodiment of the second aspect of the present invention, the parameters of the mixer are: mixing for 70-100 seconds at a speed of 1000-2000 rpm / min, mixing for 40-70 seconds at a speed of 2000-4000 rpm / min, and mixing for 20-60 seconds at a speed of 500-1500 rpm / min.

[0017] In an optional embodiment of the second aspect of the present invention, the parameters of the mixer are: mixing for 90 seconds at a speed of 1500 rpm / min, mixing for 60 seconds at a speed of 2500 rpm / min, and mixing for 30 seconds at a speed of 1000 rpm / min.

[0018] A third aspect of the present invention provides the application of the alloy-type conductive plugging paste described in any of the above claims in a circuit board.

[0019] Beneficial Effects: This invention provides an alloy-type conductive via-plugging slurry, its preparation method, and its application. The alloy-type conductive via-plugging slurry comprises conductive metal powder and a mixed resin system. The conductive metal powder includes nano-tin powder, submicron copper powder, spherical silver-coated copper powder, and tin-bismuth alloy powder. The mixed resin system includes a resin binder, a glycerol ether diluent, a BYK dispersant, and an anhydride curing agent or an imidazole curing agent. The alloy-type conductive via-plugging slurry prepared by this invention utilizes a combination and overlapping of various conductive metal powders with a resin system. This slurry can achieve more stable and efficient interlayer interconnection in multilayer boards. Furthermore, it can replace traditional electroplating copper processes, achieving green and environmentally friendly production. Attached Figure Description

[0020] Figure 1 This is a flowchart of a method for preparing an alloy-type conductive plugging slurry according to the present invention.

[0021] Figure 2 This is a cross-sectional microscopic image of a multilayer board according to Embodiment 1 of the present invention.

[0022] Figure 3 This is a cross-sectional microscopic image of a multilayer board according to Embodiment 2 of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention.

[0024] The first aspect of the present invention provides an alloy-type conductive plugging slurry, comprising conductive metal powder and a mixed resin system.

[0025] In this invention, the conductive metal powder includes nano-tin powder (the particle size (D50, hereinafter the same) of the nano-tin powder is 40-60 nm, for example, the particle size of the nano-tin powder is 50 nm), submicron copper powder (the particle size of the submicron copper powder is 0.6-0.8 μm, for example, the particle size of the submicron copper powder is 0.8 μm), spherical silver-coated copper powder (the particle size of the spherical silver-coated copper powder is 2-4 μm, for example, the particle size of the spherical silver-coated copper powder is 3 μm), and tin-bismuth alloy powder (the particle size of the tin-bismuth alloy powder is 5-9 μm, for example, the particle size of the tin-bismuth alloy powder is 6 μm).

[0026] In this invention, the mixed resin system includes a resin adhesive (the resin adhesive includes epoxy resin adhesive and acrylic resin adhesive (one or more can be used simultaneously), for example, the resin adhesive is an epoxy resin adhesive), a glycerol ether diluent (the glycerol ether diluent includes dodecyl glycidyl ether and castor oil-based glycidyl ether (one or more can be used simultaneously), for example, the glycerol ether diluent is dodecyl glycidyl ether), and a BYK dispersant (the BYK dispersant includes BYK-111 dispersant and BYK-130 dispersant). The dispersant (one or more may be used in combination), for example, the BYK dispersant is BYK-111 dispersant, and the anhydride curing agent (the anhydride curing agent includes methylhexahydrophthalic anhydride curing agent and phthalic anhydride curing agent (one or more may be used in combination), for example, the anhydride curing agent is methylhexahydrophthalic anhydride curing agent) or the imidazole curing agent (the imidazole curing agent includes 2-methylimidazolium curing agent and 2-ethylimidazolium curing agent (one or more may be used in combination), for example, the imidazole curing agent is 2-methylimidazolium curing agent).

[0027] In an optional embodiment of the first aspect of the present invention, the amount of resin adhesive added, by volume ratio, is 5-10% (e.g., 5%, 6%, 8%, and 10%), the amount of glycerol ether diluent added is 1-3% (e.g., 1%, 2%, and 3%), the amount of anhydride or imidazole curing agent added is 1-3% (e.g., 1%, 2%, and 3%), the amount of nano-tin powder added is 5-8% (e.g., 5%, 6%, 7%, and 8%), and the amount of submicron copper powder added is 25-30% (e.g., ...). The amounts of spherical silver-coated copper powder, tin-bismuth alloy powder, and nano-tin powder are 25%, 27%, 29%, and 30%, respectively. The amounts of spherical silver-coated copper powder, tin-bismuth alloy powder, and tin-bismuth alloy powder are 30-35% (e.g., 30%, 32%, 33%, and 35%). The amount of BYK dispersant is 0.5-1 wt% (e.g., 0.5 wt%, 0.6 wt%, 0.8 wt%, and 1 wt%) of the total mass of nano-tin powder, submicron copper powder, spherical silver-coated copper powder, and tin-bismuth alloy powder. It should be noted that in this application, the volume of nano-tin powder, submicron copper powder, spherical silver-coated copper powder, and tin-bismuth alloy powder can be measured by pouring the powder into a measuring container (e.g., a graduated cylinder) and applying a fixed pressure to flatten the surface.

[0028] See Figure 1 The second aspect of the present invention provides a method for preparing an alloy-type conductive plugging slurry, comprising:

[0029] S100. Provides conductive metal powder and a mixed resin system, wherein the conductive metal powder includes nano tin powder, submicron copper powder, spherical silver-coated copper powder and tin-bismuth alloy powder, and the mixed resin system includes resin binder, glycerol ether diluent, BYK dispersant and acid anhydride curing agent or imidazole curing agent.

[0030] S200. The conductive metal powder and the mixed resin system are mixed by a mixer (the parameters of the mixer are 1000-2000 rpm / min for 70-100s, 2000-4000 rpm / min for 40-70s, and 500-1500 rpm / min for 20-60s) to obtain an alloy-type conductive plugging slurry.

[0031] In an optional embodiment of the second aspect of the present invention, the parameters of the mixer are: mixing for 90 seconds at a speed of 1500 rpm / min, mixing for 60 seconds at a speed of 2500 rpm / min, and mixing for 30 seconds at a speed of 1000 rpm / min.

[0032] Furthermore, a third aspect of the present invention provides the application of the alloy-type conductive plugging paste described in any of the above claims in a circuit board.

[0033] To better verify the technical effect of the UV-resistant heat-insulating composite material of the present invention, the present invention provides the following specific embodiments and conducts relevant performance tests.

[0034] Example 1: Preparation of alloy-type conductive plugging slurry: The epoxy resin system is composed of Hongchang Electronics 128 liquid epoxy resin as binder, dodecyl glycidyl ether as diluent, BYK-111 as dispersant, and methyl hexahydrophthalic anhydride curing agent. A resin system was prepared by thoroughly mixing 5% 128 liquid epoxy resin, 2% dodecyl glycidyl ether, 1 wt% BYK-111 dispersant, and 3% methylhexahydrophthalic anhydride. A high-speed mixer was used to mix the epoxy resin system with 5% 50nm nano-tin powder, 25% 800nm ​​tin powder, 35% 3μm spherical silver-coated copper powder, and 25% 6μm tin-bismuth alloy powder. The mixture was then mixed with the epoxy resin system to obtain an alloy-type conductive via-plugging paste. The via-plugging paste was screen-printed into the holes of a multilayer board to test the printing life. After high-temperature pressing at 280℃, the conductivity was tested. The printing life and conductivity results of the alloy-type conductive via-plugging paste in Example 1 are shown in Table 1 (1#). The cross-sectional microscopic image can be found in [reference needed]. Figure 2 .

[0035] Example 2: Preparation of alloy-type conductive plugging slurry: E51 liquid epoxy resin is used as binder, castor oil-based glycidyl ether as diluent, BYK-111 as dispersant, and creeping curing agent 8150 as curing agent to form an epoxy resin system. A resin system was prepared by thoroughly mixing 5% E51 liquid epoxy resin, 2% castor oil-based glycidyl ether, 1 wt% BYK-111 dispersant, and 3% creeping curing agent 8150. A high-speed mixer was used to mix the epoxy resin system with 5% 50nm nano-tin powder, 30% 800nm ​​tin powder, 30% 3μm spherical silver-coated copper powder, and 25% 6μm tin-bismuth alloy powder. The mixture was then mixed with the epoxy resin system in a high-speed mixer (90s at 1500rpm / min, 60s at 2500rpm / min, and 30s at 1000rpm / min) to obtain an alloy-type conductive via-plugging slurry. The via-plugging slurry was screen-printed into the holes of a multilayer board to test the printing life. The conductivity was tested after high-temperature pressing at 280℃. The printing life and conductivity of the alloy-type conductive via-plugging slurry in Example 2 are shown in Table 1, #2. The cross-sectional microscopic image can be found in [reference needed]. Figure 3 .

[0036] Table 1. Validation Results of Alloy-Type Conductive Pore-Pluging Slurry

[0037]

[0038]

[0039] As shown in Table 1 above, the alloy-type conductive plugging paste prepared by the present invention has a high printing life and high conductivity. Furthermore, the microscopic cross-sectional photographs show that it can form a good alloy layer with the copper layer, which greatly improves the stability of interlayer interconnection.

[0040] In summary, this invention provides an alloy-type conductive via-plugging slurry, its preparation method, and its applications. The alloy-type conductive via-plugging slurry comprises conductive metal powder and a mixed resin system. The conductive metal powder includes nano-tin powder, submicron copper powder, spherical silver-coated copper powder, and tin-bismuth alloy powder. The mixed resin system includes a resin binder, a glycerol ether diluent, a BYK dispersant, and an anhydride curing agent or an imidazole curing agent. The alloy-type conductive via-plugging slurry prepared by this invention, using a resin system combined with metal alloy powders of different sizes and types, can achieve more stable and efficient interlayer interconnection of multilayer boards. Furthermore, it can replace the traditional electroplating copper process, achieving green and environmentally friendly production, and providing a better solution for interlayer interconnection of 5G high-frequency and high-speed multilayer boards.

[0041] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An alloy-type conductive plugging slurry, characterized in that, The slurry comprises conductive metal powder and a mixed resin system; the conductive metal powder comprises nano-tin powder, submicron copper powder, spherical silver-coated copper powder, and tin-bismuth alloy powder; the mixed resin system comprises resin binder, glycerol ether diluent, BYK dispersant, and anhydride curing agent or imidazole curing agent. The composition, by volume ratio, includes 5-10% resin adhesive, 1-3% glycerol ether diluent, 1-3% anhydride or imidazole curing agent, 5-8% nano-tin powder, 25-30% submicron copper powder, 30-35% spherical silver-coated copper powder, and 20-25% tin-bismuth alloy powder; the amount of BYK dispersant is 0.5-1 wt% of the total mass of nano-tin powder, submicron copper powder, spherical silver-coated copper powder, and tin-bismuth alloy powder. The nano-tin powder has a particle size of 40~60 nm; the submicron copper powder has a particle size of 0.6~0.8 μm; the spherical silver-coated copper powder has a particle size of 2~4 μm; and the tin-bismuth alloy powder has a particle size of 5~9 μm.

2. The alloy-type conductive plugging slurry according to claim 1, characterized in that, The resin adhesive includes one or more of epoxy resin adhesive and acrylic resin adhesive; the glycerol ether diluent includes one or more of dodecyl glycidyl ether and castor oil-based glycidyl ether; the BYK dispersant includes BYK-111 dispersant; the acid anhydride curing agent includes methylhexahydrophthalic anhydride curing agent; and the imidazole curing agent includes 2-methylimidazolium curing agent.

3. The alloy-type conductive plugging slurry according to claim 1, characterized in that, The mixed resin system includes an epoxy resin adhesive, dodecyl glycidyl ether, BYK-111 dispersant, and methyl hexahydrophthalic anhydride curing agent.

4. The alloy-type conductive plugging slurry according to claim 1, characterized in that, The nano-tin powder has a particle size of 50 nm; the submicron copper powder has a particle size of 0.8 μm; the spherical silver-coated copper powder has a particle size of 3 μm; and the tin-bismuth alloy powder has a particle size of 6 μm.

5. The method for preparing the alloy-type conductive plugging slurry according to any one of claims 1-4, characterized in that, The conductive metal powder and the mixed resin system are mixed using a high-speed mixer to obtain an alloy-type conductive plugging slurry.

6. The method for preparing the alloy-type conductive plugging slurry according to claim 5, characterized in that, The parameters of the high-speed mixer are as follows: mixing for 70-100 seconds at a speed of 1000-2000 rpm / min, mixing for 40-70 seconds at a speed of 2000-4000 rpm / min, and mixing for 20-60 seconds at a speed of 500-1500 rpm / min.

7. The method for preparing the alloy-type conductive plugging slurry according to claim 6, characterized in that, The parameters of the high-speed mixer are: mixing for 90 seconds at 1500 rpm / min, mixing for 60 seconds at 2500 rpm / min, and mixing for 30 seconds at 1000 rpm / min.

8. The application of the alloy-type conductive plugging paste according to any one of claims 1-3 in a circuit board.

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