Multi-scale micro-nano particle composite soldering paste for field of electronic packaging and preparation method of multi-scale micro-nano particle composite soldering paste

Abstract

The invention provides the multi-scale micro-nano particle composite soldering paste for the field of electronic packaging and a preparation method and an application process of the multi-scale micro-nano particle composite soldering paste. The novel composite soldering paste is formed by mixing metal powder and a soldering flux, the metal powder is composed of 30 to 70 nm in particle size and 3 to 7 microns, 15 to 25 microns of Cu @ Ag particles, 40 to 60 nm of Ni @Ag particles and 1 to 2 microns of Ag particles, the scaling powder is composed of solvent isopropanol, an active agent stearicacid, a film-forming agent mixed rosin, polyethylene glycol, a modifier triethanolamine and a surfactant octylphenol polyoxyethylene ether, the existence of Cu @ Ag particles in the composite solder paste is reduced relative to the cost of the nano-silver solder paste, the electromigration resistance can be improved, the Ag particles can protect the integrity of the Cu @ Ag core-shell structure, under a high-frequency induction process condition, the magnetism of the Ni @ Ag particles ni enables the particle distribution to be more uniform, the density is improved, and the electric conductionheat conduction performance is improved. The method is low in cost, simple and controllable in process and high in efficiency, the problems that an existing device pasting material is high in cost, low in service temperature, long in process time and the like are solved.

Description

technical field

[0001] The invention relates to a composite solder paste and a preparation method thereof. Background technique

[0002] At present, high-power semiconductor devices are widely used in automotive electronics, high-speed locomotives, energy transmission and other fields, and the service temperature is close to 200°C, but the solder used for electrode lead-out materials and chip packaging cannot work normally at this temperature. Moreover, due to increasingly strict environmental protection regulations and people's increasing awareness of environmental protection, it is no longer in line with the current application environment, and the existing mainstream solders such as SnAgCu series, SnZn series, SnSb series and other solders have their own performance and cost deficiencies. , It is difficult to meet the working requirements that can be bonded at low temperature and serve at high temperature. Therefore, it is urgent to develop lead-free interconnect material...

Examples

Embodiment 1

[0044] Example 1 Preparation of particles with a particle size of 30-70nm Cu@Ag core-shell structure.

[0045] The first step is to weigh 1g of copper powder with a particle size of about 50nm, add it to a sulfuric acid solution with a volume concentration of 20%, and perform centrifugation and washing.

[0046] In the second step, mix the silver nitrate solution with a concentration of 0.08g / L and 3.2% sodium hydroxide solution, and then add ammonia water with a mass fraction of 20% drop by drop until the precipitation disappears, that is, a silver ammonia solution is prepared.

[0047] The third step is to mix absolute ethanol and deionized water according to the volume ratio of 1:4, add 40ml of ethanol, 160ml of deionized water, add the copper powder treated in step 1, add 0.5g of dispersant PVP, and at the same time Add the above prepared silver ammonia solution and 0.75g reducing agent hydrazine hydrate, adjust the pH value of the reaction solution to 9~13, and stir the r...

Embodiment 2

[0049] Example 2 Preparation of particles with a particle size of 3-7 μm Cu@Ag core-shell structure.

[0050] The first step is to weigh 1 g of copper powder with a particle size of about 5 μm, add it to a sulfuric acid solution with a volume concentration of 20%, and perform centrifugation and washing.

[0051] The second step is to prepare silver ammonia solution: mix the silver nitrate solution with a concentration of 0.2625g / L and 3.2% sodium hydroxide solution, and then add ammonia water with a mass fraction of 20% drop by drop until the precipitation disappears, that is, silver ammonia is prepared solution.

[0052] The third step is to mix absolute ethanol and deionized water according to the volume ratio of 1:4, add 40ml of ethanol, 160ml of deionized water, add the copper powder treated in step 1, add 0.5g of dispersant PVP, and at the same time Add the above prepared silver ammonia solution and 0.75g reducing agent hydrazine hydrate, adjust the pH value of the react...

Embodiment 3

[0054] Example 3 Preparation of particles with a particle size of 15-25 μm Cu@Ag core-shell structure.

[0055] The first step is to weigh 1 g of copper powder with a particle size of about 20 μm, add it to a sulfuric acid solution with a volume concentration of 20%, and perform centrifugation and washing.

[0056] In the second step, mix the silver nitrate solution with a concentration of 0.6575g / L and 3.2% sodium hydroxide solution, and then add ammonia water with a mass fraction of 20% drop by drop until the precipitate disappears, that is, a silver ammonia solution is prepared.

[0057] The third step is to mix absolute ethanol and deionized water according to the volume ratio of 1:4, add 40ml of ethanol, 160ml of deionized water, add the copper powder treated in step 1, add 0.5g of dispersant PVP, and at the same time Add the above prepared silver ammonia solution and 0.75g reducing agent hydrazine hydrate, adjust the pH value of the reaction solution to 9~13, stir the re...

technical field

[0001] The invention relates to a composite solder paste and a preparation method thereof. Background technique

[0002] At present, high-power semiconductor devices are widely used in automotive electronics, high-speed locomotives, energy transmission and other fields, and the service temperature is close to 200°C, but the solder used for electrode lead-out materials and chip packaging cannot work normally at this temperature. Moreover, due to increasingly strict environmental protection regulations and people's increasing awareness of environmental protection, it is no longer in line with the current application environment, and the existing mainstream solders such as SnAgCu series, SnZn series, SnSb series and other solders have their own performance and cost deficiencies. , It is difficult to meet the working requirements that can be bonded at low temperature and serve at high temperature. Therefore, it is urgent to develop lead-free interconnect material...

Examples

Embodiment 1

[0044] Example 1 Preparation of particles with a particle size of 30-70nm Cu@Ag core-shell structure.

[0045] The first step is to weigh 1g of copper powder with a particle size of about 50nm, add it to a sulfuric acid solution with a volume concentration of 20%, and perform centrifugation and washing.

[0046] In the second step, mix the silver nitrate solution with a concentration of 0.08g / L and 3.2% sodium hydroxide solution, and then add ammonia water with a mass fraction of 20% drop by drop until the precipitation disappears, that is, a silver ammonia solution is prepared.

[0047] The third step is to mix absolute ethanol and deionized water according to the volume ratio of 1:4, add 40ml of ethanol, 160ml of deionized water, add the copper powder treated in step 1, add 0.5g of dispersant PVP, and at the same time Add the above prepared silver ammonia solution and 0.75g reducing agent hydrazine hydrate, adjust the pH value of the reaction solution to 9~13, and stir the r...

Embodiment 2

[0049] Example 2 Preparation of particles with a particle size of 3-7 μm Cu@Ag core-shell structure.

[0050] The first step is to weigh 1 g of copper powder with a particle size of about 5 μm, add it to a sulfuric acid solution with a volume concentration of 20%, and perform centrifugation and washing.

[0051] The second step is to prepare silver ammonia solution: mix the silver nitrate solution with a concentration of 0.2625g / L and 3.2% sodium hydroxide solution, and then add ammonia water with a mass fraction of 20% drop by drop until the precipitation disappears, that is, silver ammonia is prepared solution.

[0052] The third step is to mix absolute ethanol and deionized water according to the volume ratio of 1:4, add 40ml of ethanol, 160ml of deionized water, add the copper powder treated in step 1, add 0.5g of dispersant PVP, and at the same time Add the above prepared silver ammonia solution and 0.75g reducing agent hydrazine hydrate, adjust the pH value of the react...

Embodiment 3

[0054] Example 3 Preparation of particles with a particle size of 15-25 μm Cu@Ag core-shell structure.

[0055] The first step is to weigh 1 g of copper powder with a particle size of about 20 μm, add it to a sulfuric acid solution with a volume concentration of 20%, and perform centrifugation and washing.

[0056] In the second step, mix the silver nitrate solution with a concentration of 0.6575g / L and 3.2% sodium hydroxide solution, and then add ammonia water with a mass fraction of 20% drop by drop until the precipitate disappears, that is, a silver ammonia solution is prepared.

[0057] The third step is to mix absolute ethanol and deionized water according to the volume ratio of 1:4, add 40ml of ethanol, 160ml of deionized water, add the copper powder treated in step 1, add 0.5g of dispersant PVP, and at the same time Add the above prepared silver ammonia solution and 0.75g reducing agent hydrazine hydrate, adjust the pH value of the reaction solution to 9~13, stir the re...

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