Interconnection material for electronic packaging and preparation method thereof

Abstract

The invention relates to an interconnection material for electronic packaging and a preparation method thereof, and relates to the technical field of electronic packaging, and the interconnection material is prepared from the following components in parts by weight: 60-70 parts of tin-based alloy, 8-15 parts of graphene modified polybenzoxazine resin, 8-12 parts of silver nanowires, 3-5 parts of indium, 1-3 parts of nickel and 0.1-0.3 part of rare earth elements. The interconnection material for electronic packaging is high in conductivity and excellent in flexibility and thermal cycle reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic packaging, and in particular to an interconnection material for electronic packaging and a preparation method thereof. Background Art

[0002] With the rapid development of electronic information technology, electronic devices are moving towards miniaturization, high density, and multifunctionality, placing higher demands on interconnect materials used in electronic packaging. Traditional interconnect materials, such as tin-lead solder, face increasingly stringent environmental restrictions due to the toxicity of lead. Furthermore, their mechanical properties and high-temperature resistance are no longer sufficient to meet the demands of high-end electronic packaging.

[0003] As electronic packaging technology evolves toward high-density, three-dimensional integration, the limitations of traditional metal-based interconnect materials in terms of flexibility, interfacial compatibility, and environmental stress resistance are becoming increasingly prominent. For example, in flexible electronic devices or heterogeneous material packaging, metal interconnect layers are prone to stress concentration due to mismatched thermal expansion coefficients, leading to interfacial cracking. While existing organic-inorganic composite interconnect materials possess a certain degree of flexibility, the introduction of the organic phase is often accompanied by decreased electrical conductivity and insufficient high-temperature resistance, making it difficult to simultaneously meet the dual requirements of electrical performance and mechanical adaptability. Currently, some research attempts to improve flexibility by adding a polymer matrix to metal solders. However, common organic components such as epoxy resins or silicone rubber have weak interfacial bonding with the metal matrix and are prone to degradation at high temperatures, resulting in reduced reliability of the interconnect structure. Furthermore, the addition of organic components can affect the wettability of the molten metal, leading to defects such as cold solder joints and voids during the packaging process.

[0004] To address the aforementioned issues, Chinese invention patent CN107214333B discloses an interconnect material comprising an imidazole-coated nano-copper particle powder and a dispersion. The imidazole compound coating the nano-copper particles in the imidazole-coated nano-copper particle powder is selected from one or more of benzotriazole, alkylimidazole, benzimidazole, alkylbenzimidazole, and alkylphenylimidazole. This interconnect material exhibits excellent oxidation resistance and dispersibility, making it suitable for use in the manufacture of high-end electronic devices and semiconductor packaging. Furthermore, this interconnect material can lower the packaging sintering temperature of interconnected electronic components, enabling low-temperature interconnection. The invention also provides a method for preparing the interconnect material. The interconnect material produced according to this method is a nano-copper paste interconnect material with excellent oxidation resistance. The imidazole-coated copper particle powder in the interconnect material paste is uniformly dispersed, and the copper particles are monodispersed, nanoscale particles. However, its electrical conductivity, flexibility, and thermal cycling reliability still require further improvement.

[0005] It can be seen that the development of an interconnect material for electronic packaging with high electrical conductivity, excellent flexibility and thermal cycle reliability and its preparation method meets market demand, has broad market value and application prospects, and is of great significance to promoting the development of the field of interconnect materials for electronic packaging. Summary of the Invention

[0006] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide an electronic packaging interconnect material having high electrical conductivity, excellent flexibility and thermal cycle reliability and a preparation method thereof.

[0007] To achieve the above-mentioned object, the technical solution adopted by the present invention is an interconnection material for electronic packaging, which comprises the following components in parts by weight: 60-70 parts of tin-based alloy, 8-15 parts of graphene-modified polybenzoxazine resin, 8-12 parts of nanosilver wire, 3-5 parts of indium, 1-3 parts of nickel, and 0.1-0.3 parts of rare earth elements.

[0008] Preferably, the tin-based alloy comprises the following components in percentage by mass: 3-5% silver, 1-3% copper, 1-3% bismuth, 1-3% zinc, 0.1-0.3% antimony, 0.05-0.1% titanium, 1-2% copper, and the balance being tin.

[0009] Preferably, the graphene-modified polybenzoxazine resin is prepared by the following method: dispersing graphene oxide in benzoxazine monomer, ultrasonically treating at 80-100° C. for 1-2 hours, then adding a catalyst, and polymerizing at 120-150° C. for 4-6 hours to obtain the graphene-modified polybenzoxazine resin.

[0010] Preferably, the graphene oxide is a single-layer graphene oxide with a sheet diameter of 0.5-5 μm and a thickness of 0.8-1.2 nm.

[0011] Preferably, the mass ratio of the graphene oxide, benzoxazine monomer, and catalyst is (1-3):100:(0.5-1).

[0012] Preferably, the catalyst is a mixture of p-toluenesulfonic acid, stannous octoate, and phosphotungstic acid in a mass ratio of 1:(0.8-1.2):(0.5-1).

[0013] Preferably, the benzoxazine monomer is bisphenol A-aniline type benzoxazine.

[0014] Preferably, the average diameter of the silver nanowires is 30 nm and the length is 20 μm.

[0015] Preferably, the rare earth element is at least one of lanthanum, cerium and praseodymium.

[0016] Another object of the present invention is to provide a method for preparing the interconnect material for electronic packaging, comprising the following steps: Step S1: heating the graphene-modified polybenzoxazine resin to 150-180° C. to melt, adding the silver nanowires, and stirring at 300-500 rpm for 30 minutes to form a uniform organic-inorganic composite phase; Step S2: placing the metal components into a vacuum melting furnace for melting; Step S3: slowly adding the organic-organic composite phase to the metal melt, stirring at 150-200 rpm at 350-400° C. for 40-50 minutes to form a uniform metal-organic composite melt; Step S4: pouring the composite melt into a mold preheated to 118-122°C, cooling at a rate of 7-9°C / min under nitrogen protection, and demolding to obtain a green body; placing the green body in an oven at 175-185°C for post-curing treatment for 2-4 hours.

[0017] Due to the application of the above technical solution, the present invention has the following beneficial effects: (1) The method for preparing the interconnect material for electronic packaging disclosed in the present invention has a simple process, convenient operation and control, high preparation efficiency and finished product qualification rate, low dependence on equipment, easy large-scale industrial production, and high promotion and application value.

[0018] (2) The interconnect material for electronic packaging disclosed in the present invention comprises the following components in parts by weight: 60-70 parts of tin-based alloy, 8-15 parts of graphene-modified polybenzoxazine resin, 8-12 parts of nano silver wire, 3-5 parts of indium, 1-3 parts of nickel, and 0.1-0.3 parts of rare earth elements. Through the mutual cooperation between the components, the interconnect material has high electrical conductivity, excellent flexibility and thermal cycle reliability. The tin-based alloy comprises the following components in mass percentage: 3-5% silver, 1-3% copper, 1-3% bismuth, 1-3% zinc, 0.1-0.3% antimony, 0.05-0.1% titanium, 1-2% copper, and the balance is tin; through the cooperation of the above components, the thermal expansion coefficient of the tin-based alloy can be adjusted so that the difference between the thermal expansion coefficient of the tin-based alloy and the organic phase is reduced, thereby enhancing the thermal stress transfer capacity of the interface. The composite design of graphene-modified polybenzoxazine resin and silver nanowires improves mechanical properties while maintaining electrical conductivity close to that of traditional solders. The π-π conjugation between graphene and polybenzoxazine enhances the rigidity of the organic phase, while the silver nanowires form a conductive network within the organic phase, compensating for the conductivity loss of the polymer matrix. The indium element in the metallic phase lowers the melting point of the alloy and forms coordination bonds with nitrogen atoms in the organic phase, strengthening the interfacial bonding. (3) In the interconnect material for electronic packaging disclosed in the present invention, the addition of rare earth elements can serve as a "molecular bridge" connecting the metal matrix and the benzene ring structure of polybenzoxazine; it can also refine the metal grains, increase the interfacial contact area, and neutralize the polar groups in the organic phase, reducing the interfacial energy. This dual effect of "chemical bonding and physical anchoring" significantly improves the interfacial bonding strength. DETAILED DESCRIPTION

[0019] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are merely examples, and those skilled in the art may conceive of other obvious variations.

[0020] Example 1 An interconnection material for electronic packaging comprises the following components in parts by weight: 60 parts of tin-based alloy, 8 parts of graphene-modified polybenzoxazine resin, 8 parts of nano silver wires, 3 parts of indium, 1 part of nickel, and 0.1 part of rare earth elements.

[0021] The tin-based alloy includes the following components by mass percentage: 3% silver, 1% copper, 1% bismuth, 1% zinc, 0.1% antimony, 0.05% titanium, 1% copper, and the balance being tin.

[0022] The graphene-modified polybenzoxazine resin is prepared by the following method: dispersing graphene oxide in a benzoxazine monomer, ultrasonically treating the mixture at 80°C for 1 hour, then adding a catalyst, and polymerizing the mixture at 120°C for 4 hours to obtain the graphene-modified polybenzoxazine resin; the graphene oxide is a single-layer graphene oxide with a sheet diameter of 0.5-5 μm and a thickness of 0.8-1.2 nm; the mass ratio of the graphene oxide, the benzoxazine monomer, and the catalyst is 1:100:0.5; the catalyst is a mixture of p-toluenesulfonic acid, stannous octoate, and phosphotungstic acid in a mass ratio of 1:0.8:0.5; and the benzoxazine monomer is a bisphenol A-aniline type benzoxazine.

[0023] The average diameter of the silver nanowire is 30 nm and the length is 20 μm; the rare earth element is lanthanum.

[0024] A method for preparing the interconnect material for electronic packaging comprises the following steps: Step S1: heating the graphene-modified polybenzoxazine resin to 150° C. to melt, adding silver nanowires, and stirring at 300 rpm for 30 minutes to form a uniform organic-inorganic composite phase; Step S2: placing the metal components into a vacuum melting furnace for melting; Step S3: slowly adding the organic-organic composite phase into the metal melt, stirring at 150 rpm at 350° C. for 40 minutes to form a uniform metal-organic composite melt; Step S4: pouring the composite melt into a mold preheated to 118°C, cooling at a rate of 7°C / min under nitrogen protection, and demolding to obtain a green body; placing the green body in a 175°C oven for post-curing treatment for 2 hours.

[0025] Example 2 An interconnection material for electronic packaging comprises the following components in parts by weight: 63 parts of tin-based alloy, 10 parts of graphene-modified polybenzoxazine resin, 9 parts of nano silver wires, 3.5 parts of indium, 1.5 parts of nickel, and 0.15 parts of rare earth elements.

[0026] The tin-based alloy includes the following components by mass percentage: 3.5% silver, 1.5% copper, 1.5% bismuth, 1.5% zinc, 0.15% antimony, 0.06% titanium, 1.2% copper, and the balance being tin.

[0027] The graphene-modified polybenzoxazine resin is prepared by the following method: dispersing graphene oxide in a benzoxazine monomer, ultrasonically treating the mixture at 85° C. for 1.2 hours, then adding a catalyst, and polymerizing the mixture at 130° C. for 4.5 hours to obtain the graphene-modified polybenzoxazine resin; the graphene oxide is a single-layer graphene oxide with a sheet diameter of 0.5-5 μm and a thickness of 0.8-1.2 nm; the mass ratio of the graphene oxide, the benzoxazine monomer, and the catalyst is 1.5:100:0.7; the catalyst is a mixture of p-toluenesulfonic acid, stannous octoate, and phosphotungstic acid in a mass ratio of 1:0.9:0.6; the benzoxazine monomer is bisphenol A-aniline benzoxazine; the silver nanowires have an average diameter of 30 nm and a length of 20 μm; and the rare earth element is cerium.

[0028] A method for preparing the interconnect material for electronic packaging comprises the following steps: Step S1: heating the graphene-modified polybenzoxazine resin to 160° C. to melt, adding the silver nanowires, and stirring at 350 rpm for 30 minutes to form a uniform organic-inorganic composite phase; Step S2: placing the metal components into a vacuum melting furnace for melting; Step S3: slowly adding the organic-organic composite phase to the metal melt, stirring at 170 rpm at 360° C. for 43 minutes to form a uniform metal-organic composite melt; Step S4: pouring the composite melt into a mold preheated to 119°C, cooling at a rate of 7.5°C / min under nitrogen protection, and demolding to obtain a green body; placing the green body in an oven at 178°C for post-curing treatment for 2.5 hours.

[0029] Example 3 An interconnection material for electronic packaging comprises the following components in parts by weight: 65 parts of tin-based alloy, 12 parts of graphene-modified polybenzoxazine resin, 10 parts of nano silver wires, 4 parts of indium, 2 parts of nickel, and 0.2 parts of rare earth elements.

[0030] The tin-based alloy includes the following components by mass percentage: 4% silver, 2% copper, 2% bismuth, 2% zinc, 0.2% antimony, 0.08% titanium, 1.5% copper, and the balance being tin.

[0031] The graphene-modified polybenzoxazine resin is prepared by the following method: dispersing graphene oxide in a benzoxazine monomer, ultrasonically treating the mixture at 90°C for 1.5 hours, then adding a catalyst, and polymerizing the mixture at 135°C for 5 hours to obtain the graphene-modified polybenzoxazine resin; the graphene oxide is a single-layer graphene oxide with a sheet diameter of 0.5-5 μm and a thickness of 0.8-1.2 nm; the mass ratio of the graphene oxide, the benzoxazine monomer, and the catalyst is 2:100:0.8; the catalyst is a mixture of p-toluenesulfonic acid, stannous octoate, and phosphotungstic acid in a mass ratio of 1:1:0.8; the benzoxazine monomer is bisphenol A-aniline benzoxazine; the silver nanowires have an average diameter of 30 nm and a length of 20 μm; and the rare earth element is praseodymium.

[0032] A method for preparing the interconnect material for electronic packaging comprises the following steps: Step S1: heating the graphene-modified polybenzoxazine resin to 165° C. to melt, adding the silver nanowires, and stirring at 400 rpm for 30 minutes to form a uniform organic-inorganic composite phase; Step S2: placing the metal components into a vacuum melting furnace for melting; Step S3: slowly adding the organic-organic composite phase into the metal melt, stirring at 170 rpm at 370° C. for 45 minutes to form a uniform metal-organic composite melt; Step S4: pouring the composite melt into a mold preheated to 120°C, cooling at a rate of 8°C / min under nitrogen protection, and demolding to obtain a green body; placing the green body in an oven at 180°C for post-curing treatment for 3 hours.

[0033] Example 4 An interconnection material for electronic packaging is made of the following components in parts by weight: 68 parts of tin-based alloy, 13 parts of graphene-modified polybenzoxazine resin, 11 parts of nano silver wires, 4.5 parts of indium, 2.5 parts of nickel, and 0.25 parts of rare earth elements.

[0034] The tin-based alloy includes the following components by mass percentage: 4.5% silver, 2.5% copper, 2.5% bismuth, 2.5% zinc, 0.25% antimony, 0.09% titanium, 1.9% copper, and the balance is tin.

[0035] The graphene-modified polybenzoxazine resin is prepared by the following method: dispersing graphene oxide in a benzoxazine monomer, ultrasonically treating the mixture at 95° C. for 1.8 hours, then adding a catalyst, and polymerizing the mixture at 145° C. for 5.5 hours to obtain the graphene-modified polybenzoxazine resin; the graphene oxide is a single-layer graphene oxide with a sheet diameter of 0.5-5 μm and a thickness of 0.8-1.2 nm; the mass ratio of the graphene oxide, the benzoxazine monomer, and the catalyst is 2.5:100:0.9; the catalyst is a mixture of p-toluenesulfonic acid, stannous octoate, and phosphotungstic acid in a mass ratio of 1:1.1:0.9; the benzoxazine monomer is bisphenol A-aniline benzoxazine; the nanosilver wires have an average diameter of 30 nm and a length of 20 μm; and the rare earth elements are a mixture of lanthanum, cerium, and praseodymium in a mass ratio of 1:2:3.

[0036] A method for preparing the interconnect material for electronic packaging comprises the following steps: Step S1: heating the graphene-modified polybenzoxazine resin to 175° C. to melt, adding silver nanowires, and stirring at 450 rpm for 30 minutes to form a uniform organic-inorganic composite phase; Step S2: placing the metal components into a vacuum melting furnace for melting; Step S3: slowly adding the organic-organic composite phase to the metal melt, stirring at 190 rpm at 390° C. for 49 minutes to form a uniform metal-organic composite melt; Step S4: pouring the composite melt into a mold preheated to 121°C, cooling at a rate of 8.5°C / min under nitrogen protection, and demolding to obtain a green body; placing the green body in an oven at 183°C for post-curing treatment for 3.5 hours.

[0037] Example 5 An interconnection material for electronic packaging is made of the following components in parts by weight: 70 parts of tin-based alloy, 15 parts of graphene-modified polybenzoxazine resin, 12 parts of nano silver wires, 5 parts of indium, 3 parts of nickel, and 0.3 parts of rare earth elements.

[0038] The tin-based alloy includes the following components by mass percentage: 5% silver, 3% copper, 3% bismuth, 3% zinc, 0.3% antimony, 0.1% titanium, 2% copper, and the balance being tin.

[0039] The graphene-modified polybenzoxazine resin is prepared by the following method: dispersing graphene oxide in a benzoxazine monomer, ultrasonically treating the mixture at 100°C for 2 hours, then adding a catalyst, and polymerizing the mixture at 150°C for 6 hours to obtain the graphene-modified polybenzoxazine resin; the graphene oxide is a single-layer graphene oxide with a sheet diameter of 0.5-5 μm and a thickness of 0.8-1.2 nm; the mass ratio of the graphene oxide, the benzoxazine monomer, and the catalyst is 3:100:1; the catalyst is a mixture of p-toluenesulfonic acid, stannous octoate, and phosphotungstic acid in a mass ratio of 1:1.2:1; the benzoxazine monomer is bisphenol A-aniline benzoxazine; the silver nanowires have an average diameter of 30 nm and a length of 20 μm; and the rare earth element is lanthanum.

[0040] A method for preparing the interconnect material for electronic packaging comprises the following steps: Step S1: heating the graphene-modified polybenzoxazine resin to 180° C. to melt, adding silver nanowires, and stirring at 500 rpm for 30 minutes to form a uniform organic-inorganic composite phase; Step S2: placing the metal components into a vacuum melting furnace for melting; Step S3: slowly adding the organic-organic composite phase into the metal melt, stirring at 200 rpm at 400° C. for 50 minutes to form a uniform metal-organic composite melt; Step S4: pouring the composite melt into a mold preheated to 122°C, cooling at a rate of 9°C / min under nitrogen protection, and demolding to obtain a green body; placing the green body in an oven at 185°C for post-curing treatment for 4 hours.

[0041] Comparative Example 1 An interconnect material for electronic packaging and a preparation method thereof are basically the same as those in Example 1, except that an equal amount of tin-based alloy is used instead of nano silver wires; and no antimony and zinc are added.

[0042] Comparative Example 2 An interconnect material for electronic packaging and a preparation method thereof are basically the same as those in Example 1, except that an equal amount of tin-based alloy is used instead of the graphene-modified polybenzoxazine resin, and bismuth and titanium are not added.

[0043] In order to further illustrate the beneficial technical effects of the electronic packaging interconnection materials involved in various embodiments of the present invention, relevant performance tests were conducted on the electronic packaging interconnection materials involved in Examples 1-5 and Comparative Examples 1-2. The test results are shown in Table 1. The test method is as follows: (1) Conductivity: Refer to GB / T 351-2019, use the four-probe method, test current 1 mA, temperature 25°C.

[0044] (2) Flexibility test: According to ASTM D790-17, a three-point bending test was performed with a span of 30 mm and a loading speed of 2 mm / min to measure the bending strength.

[0045] (3) Thermal cycle reliability test: cool down from 25°C to -40°C at a rate of 5°C / min, keep warm for 30 minutes after reaching the temperature, then heat up from -40°C to 125°C at a rate of 5°C / min, keep warm for 30 minutes after reaching the temperature, the number of cycles is 1000, and the resistance change rate is measured after the test.

[0046] Table 1 Performance test results of interconnect materials for electronic packaging project Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 <![CDATA[Conductivity (10 6 S / m)]]> 9.9 10.3 10.8 11.0 11.6 5.6 7.8 Flexural strength (MPa) 46.3 47.0 47.5 48.0 48.4 44.3 39.1 Resistance change rate after thermal cycling (%) 2.8 2.5 2.1 1.8 1.2 5.1 4.3 As can be seen from Table 1, the electronic packaging interconnect material according to the embodiment of the present invention has better conductivity, more excellent flexibility and thermal cycling reliability than the comparative example product; the combined use of nano silver wire, antimony, zinc, graphene-modified polybenzoxazine resin, bismuth and titanium is beneficial to improving the above properties.

[0047] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. An interconnect material for electronic packaging, characterized in that: The invention comprises the following components in parts by weight: 60-70 parts of tin-based alloy, 8-15 parts of graphene-modified polybenzoxazine resin, 8-12 parts of nano silver wires, 3-5 parts of indium, 1-3 parts of nickel and 0.1-0.3 parts of rare earth elements.

2. The interconnect material for electronic packaging according to claim 1, wherein The tin-based alloy includes the following components by mass percentage: 3-5% silver, 1-3% copper, 1-3% bismuth, 1-3% zinc, 0.1-0.3% antimony, 0.05-0.1% titanium, 1-2% copper, and the balance is tin.

3. The interconnect material for electronic packaging according to claim 1, wherein The graphene-modified polybenzoxazine resin is prepared by the following method: dispersing graphene oxide in benzoxazine monomer, ultrasonically treating the monomer at 80-100° C. for 1-2 hours, then adding a catalyst, and polymerizing the monomer at 120-150° C. for 4-6 hours to obtain the graphene-modified polybenzoxazine resin.

4. The interconnect material for electronic packaging according to claim 3, characterized in that The graphene oxide is a single-layer graphene oxide with a sheet diameter of 0.5-5 μm and a thickness of 0.8-1.2 nm.

5. The interconnect material for electronic packaging according to claim 3, characterized in that The mass ratio of the graphene oxide, the benzoxazine monomer, and the catalyst is (1-3):100:(0.5-1).

6. The interconnect material for electronic packaging according to claim 1, wherein The catalyst is prepared by mixing p-toluenesulfonic acid, stannous octoate and phosphotungstic acid in a mass ratio of 1:(0.8-1.2):(0.5-1).

7. The interconnect material for electronic packaging according to claim 1, wherein The benzoxazine monomer is bisphenol A-aniline benzoxazine; the average diameter of the silver nanowire is 30 nm and the length is 20 μm; and the rare earth element is at least one of lanthanum, cerium, and praseodymium.

8. A method for preparing an interconnection material for electronic packaging according to any one of claims 1 to 7, characterized in that: The steps include: Step S1: heating the graphene-modified polybenzoxazine resin to 150-180° C. to melt, adding the silver nanowires, and stirring at 300-500 rpm for 30 minutes to form a uniform organic-inorganic composite phase; Step S2: placing the metal components into a vacuum melting furnace for melting; Step S3: slowly adding the organic-organic composite phase to the metal melt, stirring at 150-200 rpm at 350-400° C. for 40-50 minutes to form a uniform metal-organic composite melt; Step S4: pouring the composite melt into a mold preheated to 118-122°C, cooling at a rate of 7-9°C / min under nitrogen protection, and demolding to obtain a green body; placing the green body in an oven at 175-185°C for post-curing treatment for 2-4 hours.