Anti-oxidation high-compactness Cu-Sn system TLPS slurry and preparation method thereof

Abstract

The invention belongs to the technical field of electronic paste, and particularly relates to anti-oxidation high-compactness Cu-Sn system TLPS paste and a preparation method thereof. The preparation method of the anti-oxidation high-compactness Cu-Sn system TLPS slurry comprises the following steps that S1, copper powder is pretreated, and pretreated copper powder is obtained; then, benzotriazole is used for carrying out surface modification treatment on the pretreated copper powder, and surface modified copper powder is obtained; s2, stirring and mixing a volatile organic matter, polybasic acid and an organic solvent to obtain an organic carrier; s3, the surface modified copper powder and tin powder are mixed to obtain a solid particle mixed phase, then the organic carrier and rosin scaling powder are added for three-roller grinding to be uniform, and anti-oxidation high-compactness Cu-Sn system TLPS slurry is obtained; the resistivity of the sintered slurry is effectively reduced, and the heat conductivity coefficient is remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of electronic paste technology, specifically relating to an anti-oxidation, high-density Cu-Sn system TLPS paste and its preparation method. Background Technology

[0002] With the rapid development of strategic emerging industries such as next-generation information technology, new energy vehicles, rail transportation, aerospace, and smart grids, the core power devices of these industries, high-power power electronic devices, are rapidly developing towards higher power density, higher switching frequency, higher operating temperature, and smaller size. This trend places unprecedentedly stringent requirements on chip packaging technology, especially the interconnect materials used in the first-level packaging: it must achieve low-temperature interconnection in the manufacturing process, while withstanding extremely high long-term operating temperatures and severe temperature cycling in service performance.

[0003] Transient Liquid Phase Sintering (TLPS) is a packaging technology developed from traditional solid-liquid interdiffusion bonding processes, enabling "low-temperature bonding and high-temperature service." This technology involves preparing a slurry from a mixture of low-melting-point and high-melting-point metal powders, coating it onto the interface to be bonded, and heating it at a temperature below the melting point of the high-melting-point metal. The low-melting-point metal melts to form a liquid phase, which wets and rapidly interdiffused with the high-melting-point metal, ultimately forming a series of high-melting-point intermetallic compounds (IMCs). The resulting IMCs have a melting point higher than that of the low-melting-point metals. Simultaneously, the liquid phase wets the surrounding high-melting-point metal, and the capillary forces generated during this process lead to atomic rearrangement and densification, thereby improving the bond strength. TLPS is a novel interconnect process that forms a high-temperature stable phase through low-temperature sintering, enabling bonding at lower temperatures and forming a high-melting-point, high-thermal-conductivity, and high-reliability interconnect layer during service.

[0004] TLPS technology perfectly overcomes the limitations of traditional brazing and solid-state sintering, demonstrating enormous application potential in fields such as third-generation semiconductor packaging, high-power device interconnection, high-temperature electronic packaging, and aerospace. As the carrier of this technology, the performance of TLPS paste directly determines the quality and reliability of the connection, thus becoming a focus of research and industrialization both domestically and internationally.

[0005] However, existing Cu-Sn system TLPS slurries have the following technical difficulties: (1) Conventional copper powder is easily oxidized to form copper oxide, which is not conducive to the contact between liquid tin and copper during sintering; (2) The diffusion rate of Cu / Sn is unbalanced during sintering, which easily leads to defects such as pores; (3) The organic carrier is not completely volatilized and decomposed before the metal melting reaction, and the carbonization residue will form pores and impurities. The above problems result in low density of the slurry after sintering, which in turn leads to increased resistivity and poor thermal conductivity.

[0006] Therefore, there is an urgent need for an anti-oxidation, high-density Cu-sn system TLPS slurry. By designing and modifying the slurry components, the resistivity of the slurry after sintering can be effectively reduced and the thermal conductivity can be significantly improved. Summary of the Invention

[0007] The purpose of this invention is to provide an anti-oxidation, high-density Cu-Sn system TLPS slurry and its preparation method. This invention uses spherical copper powder and flake copper powder as composite copper powder. After pretreatment and benzotriazole modification, surface-modified copper powder is obtained. Then, it is mixed with nano-tin powder, organic carrier and rosin flux and subjected to three-roll milling to obtain an anti-oxidation, high-density Cu-Sn system TLPS slurry, which ensures high density after sintering and obtains good comprehensive performance.

[0008] To achieve the above objectives, the present invention provides the following technical solution: The first aspect of this invention provides a method for preparing an oxidation-resistant, highly dense Cu-Sn system TLPS slurry, comprising the following steps: S1. Copper powder is pretreated to obtain pretreated copper powder; then, the pretreated copper powder is surface modified with benzotriazole to obtain surface-modified copper powder. S2. Mix volatile organic compounds, polybasic acids, and organic solvents to obtain an organic carrier; S3. The surface-modified copper powder and tin powder are mixed to obtain a solid microparticle mixed phase. Then, the organic carrier and rosin flux are added and the mixture is ground uniformly with three rollers to obtain an anti-oxidation high-density Cu-Sn system TLPS slurry.

[0009] As a preferred embodiment, the components in step S3, by weight, are: 60-80 parts of surface-modified copper powder, 10-20 parts of tin powder, 20-30 parts of organic carrier, and 1-3 parts of rosin flux.

[0010] As a preferred embodiment, the weight parts of the surface-modified copper powder in this invention can be 60 parts, 65 parts, 70 parts, 75 parts, or 80 parts, etc.

[0011] As a preferred embodiment, the weight parts of the tin powder in this invention can be 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, or 20 parts, etc.

[0012] As a preferred embodiment, the organic carrier described in this invention may be in the following weight proportions: 20 parts, 22 parts, 24 parts, 26 parts, 28 parts, or 30 parts, etc.

[0013] As a preferred embodiment, the weight of the rosin flux in this invention can be 1 part, 1.5 parts, 2 parts, 2.5 parts, or 3 parts, etc.

[0014] As a preferred embodiment, the pretreatment steps are as follows: by weight, 10-15 parts of copper powder are added to 150-200 parts of a 10% sulfuric acid solution and stirred for 30-40 minutes. After filtering to remove the acid, the solution is washed with deionized water until neutral. Then, 60-80 parts of formaldehyde solution are added, and the pH is adjusted to 11-12 with 4 mol / L sodium hydroxide solution. The solution is then transferred to a reaction vessel and pretreated at 180-200°C for 4-6 hours to obtain pretreated copper powder.

[0015] As a preferred embodiment, the copper powder is spherical copper powder or flake copper powder.

[0016] As a preferred embodiment, the mass ratio of the spherical copper powder to the flake copper powder is (1~2):1.

[0017] As a preferred embodiment, the spherical copper powder has an average particle size of 200 nm, and the flake-shaped copper powder has an average particle size of 1 μm.

[0018] This invention uses a blend of small-particle-size spherical copper powder and large-particle-size flake copper powder. The large-particle-size flake copper powder forms a good skeletal structure, which can be fully filled by the small-particle-size spherical copper powder. By controlling the mass ratio of the two, the thermal conductivity network is optimized, the thermal conductivity of the material is improved, and electron transport is smooth, effectively reducing resistivity.

[0019] As a preferred embodiment, the surface modification treatment steps are as follows: by weight, 6-10 parts of benzotriazole are added to 400-500 parts of anhydrous ethanol and stirred to dissolve. Then, 10-15 parts of pretreated copper powder are added, and the mixture is stirred at 50-60°C for 4-6 hours. The residue is then filtered, washed with water, and vacuum dried to obtain surface-modified copper powder.

[0020] This invention uses spherical copper powder and flake copper powder as a compound copper powder. After acid washing to remove impurities, hydrothermal modification pretreatment is carried out, followed by surface modification with benzotriazole to prepare surface-modified copper powder with excellent properties.

[0021] As a preferred embodiment, the tin powder is nano-tin powder; The nano-tin powder has an average particle size of 50 nm and a specific surface area of ​​19.5 m². 2 / g, with a bulk density of 0.4g / cm³ 3 .

[0022] The nano-tin powder of the present invention is more likely to form a transient liquid phase during sintering, which wets the surface of copper particles, accelerates rearrangement and eliminates pores, and is conducive to the formation of a continuous metal network, making the electron transport path smoother and thus reducing resistivity. In addition, the nano-tin powder can also promote densification, form a continuous metal thermal conduction channel, and achieve good thermal conductivity.

[0023] As a preferred embodiment, the organic carrier is prepared by adding 4-6 parts by weight of volatile organic compound and 2-4 parts by weight of polybasic acid to 20-30 parts by stirring and mixing to obtain the organic carrier.

[0024] The polyvinyl acetate in the organic carrier of this invention provides film-forming and adhesive properties, which helps the slurry adhere to the substrate; succinic acid can remove trace oxides on the surface of metal powder when heated, providing a clean interface for interdiffusion and reaction between metals, effectively reducing the porosity of the sintered body; the organic solvent is conducive to slurry leveling and provides a liquid phase environment in the early stage of sintering; through the synergistic effect of the three, the overall performance of the material is effectively improved.

[0025] As a preferred embodiment, the boiling point of the volatile organic compound is below 250°C, the boiling point of the polybasic acid is below 250°C, and the boiling point of the organic solvent is below 250°C.

[0026] As a preferred embodiment, the volatile organic compound is polyethylene acetate.

[0027] As a preferred embodiment, the polyacid is succinic acid.

[0028] As a preferred embodiment, the organic solvent is ethylene glycol or terpineol.

[0029] The organic carrier of this invention uses polyvinyl acetate as a volatile organic compound, succinic acid as a polyacid, and ethylene glycol or terpineol as an organic solvent. The boiling points of each component are all below 250°C, which can effectively ensure that the organic carrier must completely volatilize and decompose during the sintering process.

[0030] The second aspect of the present invention provides an anti-oxidation, highly dense Cu-Sn system TLPS slurry prepared by the preparation method described in the first aspect.

[0031] To achieve the above objectives, the present invention provides the following technical solution: Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: 1. This invention uses spherical copper powder and flake copper powder as a composite copper powder. After acid washing to remove impurities, hydrothermal modification pretreatment is carried out. Subsequently, benzotriazole is used for modification to obtain surface-modified copper powder. At the same time, polyethylene acetate, succinic acid and low-boiling-point organic solvent are selected to form an organic carrier. Combined with nano-level tin powder and rosin flux, an anti-oxidation high-density Cu-Sn system TLPS slurry is prepared. Through the combined action of multiple components, the resistivity of the slurry after sintering is effectively reduced and the thermal conductivity is significantly increased.

[0032] 2. The pretreatment of this invention uses sodium hydroxide solution and formaldehyde as hydrothermal reaction reagents. In the hydrothermal reaction system composed of formaldehyde and sodium hydroxide, the conversion of oxides on the surface of the spherical mixed copper powder and the regeneration of metallic copper are efficiently promoted through synergistic effects. On the one hand, formaldehyde continuously releases reduced equivalent hydrogen under high temperature and pressure, forming a reducing atmosphere that coats the surface of the copper powder and isolates trace amounts of dissolved oxygen that may exist in the hydrothermal system. On the other hand, the strong alkalinity maintained by sodium hydroxide makes the electrode potential of copper lower than the oxygen reduction potential, inhibiting the secondary oxidation of copper from a thermodynamic perspective. At the same time, the hydrogen bubbles generated in the reaction adhere to the surface of the copper powder, forming a physical barrier, further hindering the contact of oxygen molecules. Through the above process, the newly generated copper and the original copper powder achieve epitaxial growth through atomic-level bonding, ultimately forming high-purity copper powder with a dense structure and extremely low impurity content. The high-purity copper powder reduces the resistivity of the material after sintering and improves the thermal conductivity.

[0033] 3. This invention modifies the surface of copper powder with benzotriazole. Benzotriazole can effectively clean the interface and improve wetting, so that tin can spread and wet copper particles more evenly, ensuring more uniform and rapid Cu-Sn interdiffusion, effectively reducing interface defects and micropores, reducing interface contact resistance and thermal resistance, thereby achieving low resistivity and high thermal conductivity.

[0034] 4. The present invention designs a special organic carrier that matches the temperature window of a specific sintering process. This organic carrier can completely decompose and volatilize during the sintering process at 260°C, leaving no residual carbon or other impurities, thereby obtaining a densified sintered body. Densification enables the formation of continuous metal pathways between particles, reducing contact resistance and thus effectively reducing the resistivity of the material. The dense structure reduces the thermal resistance interface, improves the continuity of the thermal pathway, and significantly improves the thermal conductivity. Attached Figure Description

[0035] Figure 1 This is an optical microscope image of the slurry after sintering in Example 1. Detailed Implementation

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] The sources of some components in the examples and comparative examples are as follows: Spherical copper powder, product number JL-Cu-Y200, with an average particle size of 200nm, was purchased from Ningbo Jinlei Nanomaterials Technology Co., Ltd. Flake copper powder, product number JL-Cu-P01, with an average particle size of 1μm, was purchased from Ningbo Jinlei Nanomaterials Technology Co., Ltd. Benzotriazole, CAS No. 95-14-7, purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Nano tin powder, product number JL-Sn-N50, has an average particle size of 50nm and a specific surface area of ​​19.5m². 2 / g, with a bulk density of 0.4g / cm³ 3 Purchased from Ningbo Jinlei Nanomaterials Technology Co., Ltd. Ordinary tin powder, product number JL-Sn-W10, with an average particle size of 10µm and a specific surface area of ​​9m². 2 / g, with a bulk density of 1.4g / cm³ 3 Purchased from Ningbo Jinlei Nanomaterials Technology Co., Ltd. Polyethylene acetate, CAS No. 9003-20-7, boiling point 113℃, purchased from Shanghai Huayuan Biochemical Technology Co., Ltd. Succinic acid, CAS No. 110-15-6, boiling point 236℃, purchased from Sinopharm Chemical Reagent Co., Ltd. Sebacic acid, CAS No. 111-20-6, boiling point 374℃, purchased from Sinopharm Chemical Reagent Co., Ltd. Ethylene glycol, CAS No. 107-21-1, boiling point 197°C, purchased from Sinopharm Chemical Reagent Co., Ltd. Terpineol, CAS No. 10482-56-1, boiling point 217°C, purchased from Sinopharm Chemical Reagent Co., Ltd. Glycerol, CAS No. 56-81-5, boiling point 290℃, purchased from Sinopharm Chemical Reagent Co., Ltd. Rosin flux, model KE-100, purchased from Arakawa, Japan.

[0038] Example 1 This embodiment provides a method for preparing an oxidation-resistant, highly dense Cu-Sn system TLPS slurry, comprising the following steps: S1. By weight, 15 parts of copper powder (10 parts of spherical copper powder and 5 parts of flake copper powder) were added to 200 parts of 10% sulfuric acid solution and stirred for 40 min. After removing the acid by filtration, the mixture was washed with deionized water until neutral. Then, 80 parts of formaldehyde solution were added, and the pH was adjusted to 12 with 4 mol / L sodium hydroxide solution. The mixture was then transferred to a reaction vessel and pretreated at 200℃ for 4 h to obtain pretreated copper powder. 10 parts of benzotriazole were added to 500 parts of anhydrous ethanol and stirred to dissolve. Then, 15 parts of pretreated copper powder were added and stirred at 60℃ for 4 h. The residue was obtained by filtration, washed with water, and vacuum dried to obtain surface-modified copper powder. S2. By weight, 6 parts of polyethylene acetate and 4 parts of succinic acid are added to 30 parts of organic solvent ethylene glycol and stirred to obtain an organic carrier. S3. Mix 80 parts of surface-modified copper powder with 20 parts of nano-tin powder to obtain a solid microparticle mixed phase. Then add 30 parts of organic carrier and 3 parts of rosin flux and perform three-roll milling to obtain an anti-oxidation high-density Cu-Sn system TLPS slurry.

[0039] Example 2 This embodiment provides a method for preparing an oxidation-resistant, highly dense Cu-Sn system TLPS slurry, comprising the following steps: S1. By weight, 10 parts of copper powder (5 parts of spherical copper powder and 5 parts of flake copper powder) were added to 150 parts of 10% sulfuric acid solution and stirred for 30 min. After filtering to remove the acid, the mixture was washed with deionized water until neutral. Then, 60 parts of formaldehyde solution were added, and the pH was adjusted to 11 with 4 mol / L sodium hydroxide solution. The mixture was then transferred to a reaction vessel and pretreated at 180℃ for 6 h to obtain pretreated copper powder. 6 parts of benzotriazole were added to 400 parts of anhydrous ethanol and stirred to dissolve. Then, 10 parts of pretreated copper powder were added and stirred at 50℃ for 6 h. The residue was filtered, washed with water, and vacuum dried to obtain surface-modified copper powder. S2. By weight, add 4 parts of polyethylene acetate and 2 parts of succinic acid to 20-30 parts of organic solvent terpineol and stir to obtain an organic carrier; S3. Mix 60 parts of surface-modified copper powder with 10 parts of nano-tin powder to obtain a solid microparticle mixed phase. Then add 20 parts of organic carrier and 1 part of rosin flux and perform three-roll milling to obtain an anti-oxidation high-density Cu-Sn system TLPS slurry.

[0040] Example 3 This embodiment provides a method for preparing an oxidation-resistant, highly dense Cu-Sn system TLPS slurry, comprising the following steps: S1. By weight, 12 parts of copper powder (7 parts of spherical copper powder and 5 parts of flake copper powder) were added to 180 parts of 10% sulfuric acid solution and stirred for 35 min. After removing the acid by filtration, the mixture was washed with deionized water until neutral. Then, 70 parts of formaldehyde solution were added, and the pH was adjusted to 11.5 with 4 mol / L sodium hydroxide solution. The mixture was then transferred to a reaction vessel and pretreated at 190℃ for 5 h to obtain pretreated copper powder. 8 parts of benzotriazole were added to 450 parts of anhydrous ethanol and stirred to dissolve. Then, 12 parts of pretreated copper powder were added and stirred at 55℃ for 5 h. The residue was obtained by filtration, washed with water, and vacuum dried to obtain surface-modified copper powder. S2. By weight, 5 parts of polyethylene acetate and 3 parts of succinic acid are added to 25 parts of organic solvent ethylene glycol and stirred to obtain an organic carrier. S3. Mix 70 parts of surface-modified copper powder with 15 parts of nano-tin powder to obtain a solid microparticle mixed phase. Then add 25 parts of organic carrier and 2 parts of rosin flux and perform three-roll milling to obtain an anti-oxidation high-density Cu-Sn system TLPS slurry.

[0041] Comparative Example 1 The difference between this comparative example and Example 1 is that the amount of spherical copper powder used in the preparation of surface-modified copper powder was changed to 12 parts, and the amount of flake copper powder used was changed to 3 parts.

[0042] Comparative Example 2 The difference between this comparative example and Example 1 is that the amount of spherical copper powder used in the preparation of surface-modified copper powder was changed to 5 parts, and the amount of flake copper powder used was changed to 10 parts.

[0043] Comparative Example 3 The difference between this comparative example and Example 1 is that pretreated copper powder is used instead of surface-modified copper powder.

[0044] Comparative Example 4 The difference between this comparative example and Example 1 is that ordinary tin powder (item number JL-Sn-W10) is used instead of nano tin powder (item number JL-Sn-N50).

[0045] Comparative Example 5 The difference between this comparative example and Example 1 is that sebacic acid was used instead of succinic acid in the preparation of the organic carrier.

[0046] Comparative Example 6 The difference between this comparative example and Example 1 is that glycerol was used instead of ethylene glycol in the preparation of the organic carrier.

[0047] Performance testing (1) Solid content test: GB / T 17473-2025 Test methods for electronic paste properties - Conductor paste test (2) Resistivity and thermal conductivity tests: The slurries of the examples and comparative examples were coated onto copper plates, placed in a vacuum atmosphere furnace, and sintered into films at 260°C under a nitrogen protective atmosphere. The resistivity was measured using the four-probe method, and the thermal conductivity was measured using a thermal conductivity meter.

[0048] Table 1 Performance Test Results The performance test results above show that Examples 1-3 have the best overall effect. This is because they use spherical copper powder and flake copper powder as compound copper powder. After pretreatment and benzotriazole modification, surface-modified copper powder is obtained. Then, it is mixed with nano tin powder, organic carrier and rosin flux and subjected to three-roll milling to obtain an anti-oxidation high-density Cu-Sn system TLPS slurry, which ensures high density after sintering.

[0049] Compared to Example 1, in Comparative Example 1, the amount of spherical copper powder used in the preparation of surface-modified copper powder was changed to 12 parts and the amount of flake copper powder was changed to 3 parts. Excessive use of spherical copper powder resulted in poor compounding, leading to increased resistivity and decreased thermal conductivity of the slurry after sintering. Similarly, in Comparative Example 2, the amount of spherical copper powder used in the preparation of surface-modified copper powder was changed to 5 parts and the amount of flake copper powder was changed to 10 parts. Excessive use of flake copper powder also resulted in poor compounding, leading to increased resistivity and decreased thermal conductivity of the slurry after sintering. Finally, in Comparative Example 3, pretreated copper powder was used instead of surface-modified copper powder, lacking the surface-modifying effect of benzotriazole, resulting in increased resistivity of the slurry after sintering. The resistivity of the slurry increased and the thermal conductivity decreased compared to Example 1. In Comparative Example 4, ordinary tin powder (item number JL-Sn-W10) was used instead of nano tin powder (item number JL-Sn-N50). Due to the lack of nano tin powder, the resistivity of the slurry increased and the thermal conductivity decreased after sintering. In Comparative Example 5, sebacic acid was used instead of succinic acid to prepare the organic carrier. Due to the high boiling point of sebacic acid, the effect was not good, and the resistivity of the slurry increased and the thermal conductivity decreased after sintering. In Comparative Example 6, glycerol was used instead of ethylene glycol to prepare the organic carrier. Due to the high boiling point of glycerol, the effect was not good, and the resistivity of the slurry increased and the thermal conductivity decreased after sintering.

Claims

1. A method for preparing an oxidation-resistant, high-density Cu-Sn system TLPS slurry, characterized in that, Includes the following steps: S1. Copper powder is pretreated to obtain pretreated copper powder; then, the pretreated copper powder is surface modified with benzotriazole to obtain surface-modified copper powder. S2. Mix volatile organic compounds, polybasic acids, and organic solvents to obtain an organic carrier; S3. The surface-modified copper powder and tin powder are mixed to obtain a solid microparticle mixed phase. Then, the organic carrier and rosin flux are added and the mixture is ground uniformly with three rollers to obtain an anti-oxidation high-density Cu-Sn system TLPS slurry.

2. The method for preparing an anti-oxidation, high-density Cu-Sn system TLPS slurry according to claim 1, characterized in that, The components in step S3, by weight, are: 60-80 parts of surface-modified copper powder, 10-20 parts of tin powder, 20-30 parts of organic carrier, and 1-3 parts of rosin flux.

3. The method for preparing an anti-oxidation, high-density Cu-Sn system TLPS slurry according to claim 1, characterized in that, The pretreatment steps are as follows: by weight, 10-15 parts of copper powder are added to 150-200 parts of a 10% sulfuric acid solution and stirred for 30-40 minutes. After filtering to remove the acid, the solution is washed with deionized water until neutral. Then, 60-80 parts of formaldehyde solution are added, and the pH is adjusted to 11-12 with 4 mol / L sodium hydroxide solution. The solution is then transferred to a reaction vessel and pretreated at 180-200℃ for 4-6 hours to obtain pretreated copper powder.

4. The method for preparing an anti-oxidation, high-density Cu-Sn system TLPS slurry according to claim 1, characterized in that, The copper powder is either spherical or flake-shaped. The mass ratio of the spherical copper powder to the flake copper powder is (1~2):1; The average particle size of the spherical copper powder is 200 nm, and the average particle size of the flake copper powder is 1 μm.

5. The method for preparing an anti-oxidation, high-density Cu-Sn system TLPS slurry according to claim 1, characterized in that, The surface modification treatment steps are as follows: by weight, 6-10 parts of benzotriazole are added to 400-500 parts of anhydrous ethanol and stirred to dissolve. Then, 10-15 parts of pretreated copper powder are added and stirred at 50-60°C for 4-6 hours. The residue is obtained by filtration, washed with water, and vacuum dried to obtain surface-modified copper powder.

6. The method for preparing an anti-oxidation, high-density Cu-Sn system TLPS slurry according to claim 1, characterized in that, The tin powder is nano tin powder; The nano-tin powder has an average particle size of 50 nm and a specific surface area of ​​19.5 m². 2 / g, with a bulk density of 0.4g / cm³ 3 .

7. The method for preparing an anti-oxidation, high-density Cu-Sn system TLPS slurry according to claim 1, characterized in that, The organic carrier is prepared by adding 4-6 parts by weight of volatile organic compound and 2-4 parts by weight of polybasic acid to 20-30 parts by stirring and mixing to obtain the organic carrier.

8. The method for preparing an anti-oxidation, high-density Cu-Sn system TLPS slurry according to claim 1, characterized in that, The boiling point of the volatile organic compound is below 250°C, the boiling point of the polybasic acid is below 250°C, and the boiling point of the organic solvent is below 250°C.

9. The method for preparing an anti-oxidation, high-density Cu-Sn system TLPS slurry according to claim 1, characterized in that, The volatile organic compound is polyvinyl acetate; The polyacid is succinic acid; The organic solvent is ethylene glycol or terpineol.

10. A highly dense Cu-Sn TLPS slurry with anti-oxidation properties, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 9.

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