阅读说明：本技术 一种氮化铝/纳米银焊膏导热材料及其制备方法 (Aluminum nitride/nano-silver solder paste heat conduction material and preparation method thereof ) 是由 张平 许晖 周漫 姜雄 燕立培 杨道国 于 2019-09-11 设计创作，主要内容包括：本发明公开了一种氮化铝/纳米银焊膏导热材料及其制备方法,以表面化学镀银的纳米氮化铝作为增强相,将其掺杂在纳米银焊膏中,制得所述导热材料,其步骤为：首先对纳米氮化铝粉末进行预处理,接着用化学镀银的方式在纳米氮化铝表面镀银,最后将改性后的纳米氮化铝颗粒添加在纳米银料浆中进行混合。本发明克服了金属银与氮化铝表面较差的润湿性,制备工艺简单,得到的氮化铝/纳米银焊膏导热率较高,烧结温度较低。(The invention discloses an aluminum nitride/nano silver soldering paste heat conduction material and a preparation method thereof, nano aluminum nitride with silver plated on the surface is taken as a reinforcing phase and doped in nano silver soldering paste to prepare the heat conduction material, and the steps are as follows: firstly, preprocessing nano aluminum nitride powder, then plating silver on the surface of the nano aluminum nitride in a chemical silver plating mode, and finally adding the modified nano aluminum nitride particles into nano silver slurry for mixing. The invention overcomes the poor wettability of the metal silver and the aluminum nitride surface, the preparation process is simple, and the obtained aluminum nitride/nano silver soldering paste has high thermal conductivity and low sintering temperature.)

1. The aluminum nitride/nano silver solder paste heat conducting material is characterized in that nano aluminum nitride with silver plated on the surface is used as a reinforcing phase and is doped in nano silver solder paste.

2. A preparation method of an aluminum nitride/nano silver solder paste heat conduction material is characterized by comprising the following steps:

(1) sequentially carrying out coarsening, sensitization and activation treatment on the nano aluminum nitride particles;

(2) carrying out ammoniation modification treatment on the activated nano aluminum nitride particles to obtain ammoniated nano aluminum nitride particles;

(3) Adding the ammoniated nano aluminum nitride particles into silver ammonia solution, stirring, dropwise adding a reducing agent, cleaning the obtained precipitate, and centrifugally drying to obtain chemical silver-plated nano aluminum nitride particles;

(4) Placing the nano silver particles in an organic solvent, adding a second surfactant, ultrasonically stirring, and volatilizing the solvent in vacuum to obtain nano silver slurry;

(5) mixing the chemical silver plating nano aluminum nitride particles with the nano silver slurry, stirring until the particles are uniformly dispersed, and washing and separating to obtain the aluminum nitride/nano silver soldering paste.

3. The method of claim 2, wherein in the step (1), the nano aluminum nitride particles are added into concentrated sulfuric acid, boiled at 100 ℃ for 8 hours to be subjected to coarsening treatment, the coarsened nano aluminum nitride particles are put into sensitizing solution of 0.15mol/LSnCl ₂.2H ₂ O to be subjected to sensitizing treatment, and then put into mixed concentrated hydrochloric acid solution of 0.025mol/LPdCl ₂ to be subjected to activating treatment.

4. The method according to claim 2, wherein in the step (2), the activated nano aluminum nitride particles are added into ammonia water to obtain aminated nano aluminum nitride particles.

5. the method according to claim 2, wherein in the step (3), the ammonia water and the first surfactant are mixed in a mass ratio of 10: 1, and then dropwise adding 0.1mol/L silver nitrate aqueous solution into the mixture to obtain a silver ammonia solution, wherein the first surfactant is at least one of sodium dodecyl benzene sulfonate, sodium citrate and polyethylene glycol 200.

6. the method of claim 2, wherein in step (3), hydrazine hydrate is used as the reducing agent.

7. The method of claim 2, wherein in step (3), the magnetic stirring is carried out at a water bath temperature of 30 ~ 50 ℃ and the reducing agent is added dropwise at a dropping rate of 1.5 ~ 3.5.5 ml/min.

8. The method of claim 2, wherein in step (3), the mass ratio of the aminated nano aluminum nitride particles to the silver ammonia solution is 1: 14 ~ 18.

9. The method according to claim 2, wherein in the step (4), the organic solvent is absolute ethanol; the second surfactant is at least one of polyvinylpyrrolidone, terpineol and lauric acid, and the mass ratio of the second surfactant to the nano silver particles is 1: 17.

10. The method according to claim 2, wherein in the step (5), the mass ratio of the electroless silver-plated aluminum nitride particles to the nano silver paste is 1: 16 ~ 20.

Technical Field

The invention relates to the technical field of preparation of composite nano materials, in particular to an aluminum nitride/nano silver soldering paste heat conduction material and a preparation process thereof.

Background

Due to the rapid development of the electronic industry, higher requirements are put on the use of electronic packaging materials. The material has the advantages of good mechanical property, corrosion resistance, electrical insulation, high thermal conductivity, low expansion coefficient and the like. However, the conventional interconnection material of the chip and the substrate has the fatal defects of the material of the interconnection material and is difficult to meet the requirement. The nano silver solder paste as a novel interconnection material has excellent electric conduction and heat conduction performance, and simultaneously has higher melting point and lower sintering temperature. However, due to different applied devices, the fatal problems of gaps, fracture and the like of the nano silver solder paste in the preparation process are easily caused, and the heat dissipation capability is reduced.

At present, a great deal of research is about improving the heat conductivity of the nano-silver soldering paste and reducing the sintering temperature of the nano-silver soldering paste, but the mainly adopted approach is to improve the sintering process and add a reinforcing phase, the improvement period of the process of the nano-silver soldering paste is long, and the cost is high. In the latter, although the reinforcing phase such as graphene and diamond is added in the prior art, the problems of easy agglomeration, difficult adhesion and the like exist in the preparation process due to the activity and inertia of the material, so that the sintering temperature, the adhesion strength and the thermal conductivity of the material need to be improved, and meanwhile, the combination between the reinforcing phase and the metal interface also becomes a key factor for preparing the material.

Disclosure of Invention

The invention aims to provide an aluminum nitride/nano silver soldering paste heat conduction material and a preparation method thereof.

In order to solve the technical problems, the technical scheme provided by the invention is as follows: an aluminum nitride/nanometer silver soldering paste heat conduction material and a preparation method thereof, nanometer aluminum nitride with silver plated on the surface is used as a reinforcing phase and is doped in nanometer silver soldering paste to obtain the heat conduction material with good bonding force and good heat conductivity, and the preparation method comprises the following steps:

(1) Sequentially carrying out coarsening, sensitization and activation treatment on the nano aluminum nitride particles;

(2) Carrying out ammoniation modification treatment on the activated nano aluminum nitride particles to obtain ammoniated nano aluminum nitride particles;

(3) Adding the ammoniated nano aluminum nitride particles into silver ammonia solution, stirring, dropwise adding a reducing agent, cleaning the obtained precipitate, and centrifugally drying to obtain chemical silver-plated nano aluminum nitride particles;

(4) Placing the nano silver particles in an organic solvent, adding a second surfactant, ultrasonically stirring, and volatilizing the solvent in vacuum to obtain nano silver slurry;

(5) Mixing the chemical silver plating nano aluminum nitride particles with the nano silver slurry, stirring until the particles are uniformly dispersed, and washing and separating to obtain the aluminum nitride/nano silver soldering paste.

Further, in the step (1), adding the nano aluminum nitride particles into concentrated sulfuric acid, boiling for 8 hours at 100 ℃, performing coarsening treatment, putting the coarsened nano aluminum nitride particles into 0.15mol/L sensitizing solution of SnCl ₂ & 2H ₂ O for sensitizing treatment, and then putting the nano aluminum nitride particles into 0.025mol/L mixed solution of PdCl ₂ and concentrated hydrochloric acid for activating treatment.

Further, in the step (2), the activated nano aluminum nitride particles are added into ammonia water to obtain the aminated nano aluminum nitride particles.

further, in the step (3), the mass ratio of the ammonia water to the first surfactant is 10: 1, then dropwise adding 0.1mol/L silver nitrate aqueous solution into the mixture to prepare a silver ammonia solution, wherein the first surfactant is at least one of sodium dodecyl benzene sulfonate, sodium citrate and polyethylene glycol 200.

Further, in the step (3), hydrazine hydrate is used as the reducing agent.

Further, in the step (3), stirring by magnetic force at the water bath temperature of 30-50 ℃, and dripping a reducing agent at the dripping speed of 1.5-3.5 ml/min.

Further, in the step (3), the mass ratio of the aminated nano aluminum nitride particles to the silver ammonia solution is 1: 14 to 18.

Further, in the step (4), the organic solvent is absolute ethyl alcohol, and the second surfactant is at least one of polyvinylpyrrolidone, terpineol and lauric acid; the mass ratio of the second surfactant to the nano silver particles is 1: 17.

further, in the step (5), the mass ratio of the chemical silver-plated aluminum nitride particles to the nano silver paste is 1: 16 to 20.

Furthermore, the particle size of the nano aluminum nitride particles is 120-180 nm, and the particle size of the nano silver particles is 40-80 nm.

Compared with the prior art, the invention has the advantages that:

(1) The aluminum nitride/nano silver soldering paste prepared by the invention has high thermal conductivity.

(2) The aluminum nitride is used as a reinforcing phase, and chemical silver plating is carried out on the surface of the aluminum nitride, so that the problem that the nano material and the metal interface are difficult to combine in the prior art is solved, and meanwhile, the application process flow is simple and the production period is short.

Drawings

Fig. 1 is a process flow diagram of the aluminum nitride/nano silver solder paste heat conduction material of the invention.

Detailed Description

The invention will be further elucidated with reference to the drawings and examples, without however being limited thereto.

with reference to fig. 1, the preparation method of the aluminum nitride/nano silver solder paste heat conduction material of the present invention comprises the following steps:

(1) Adding the nano aluminum nitride particles with the particle size of 120-180 nm into concentrated sulfuric acid, boiling for 8 hours at 100 ℃, roughening, then sensitizing in 0.15mol/L SnCl ₂.2H ₂ O sensitizing solution, and finally activating in 0.025mol/L concentrated hydrochloric acid (38 wt%) mixed solution of PdCl ₂.

(2) And carrying out modification treatment on the pretreated nano aluminum nitride particles. A certain amount of the pretreated nano aluminum nitride particles are added into ammonia water (25% of analytically pure ammonia water) at normal temperature to obtain ammoniated nano aluminum nitride particles.

(3) Preparing chemical silvering nanometer aluminum nitride particles. Mixing analytically pure ammonia water and a first surfactant according to a mass ratio of 10: 1, then dropwise adding 0.1mol/L silver nitrate aqueous solution into the mixture to obtain silver ammonia solution, and mixing the ammoniated nano aluminum nitride particles according to the proportion of 1: 14-18, magnetically stirring at the water bath temperature of 30-50 ℃, dropwise adding a reducing agent hydrazine hydrate at the dropping speed of 1.5-3.5 ml/min, repeatedly washing the obtained deposit with absolute ethyl alcohol, and centrifugally drying to obtain silver-plated nano aluminum nitride particles, wherein the first surfactant is at least one of sodium dodecyl benzene sulfonate, sodium citrate and polyethylene glycol 200.

(4) And preparing nano silver paste. Adding the nano-silver particles into an organic solvent at normal temperature, and then adding a second surfactant and the nano-silver particles according to a mass ratio of 17: 1, stirring for 30min by ultrasonic waves, and evaporating the solvent in vacuum to obtain the nano-silver slurry with high thermal conductivity, wherein the organic solvent is absolute ethyl alcohol, and the second surfactant is at least one of polyvinylpyrrolidone, terpineol and lauric acid.

(5) Preparing the nano aluminum nitride/nano silver soldering paste. At normal temperature, chemically plating silver-plated nano aluminum nitride particles and nano silver slurry according to the proportion of 1: and (3) mixing the components in a mass ratio of 16-20, stirring until the particles are uniformly dispersed, and washing and separating to obtain the aluminum nitride/nano silver soldering paste.

the inventor tries to prepare the nano-silver solder paste heat conduction material doped with nano-aluminum nitride, so that the nano-silver particles are expected to be well combined with the aluminum nitride particles, the sintering temperature of the nano-silver solder paste is reduced, the heat conductivity is improved, and a unique multifunctional chip interconnection material is developed. However, in the present application, the inventors surprisingly found that when nano aluminum nitride is used as the reinforcing phase, the interface bonding force between nano aluminum nitride and nano silver particles is poor, which results in low thermal conductivity, and the addition of the aluminum nitride particles with silver coated on the surface in the nano silver solder paste effectively improves the interface bonding capability between the nano silver particles and the aluminum nitride particles, forms a phonon-electron heat transfer path, and improves the thermal conductivity.