Preparation method of copper nano-particle soldering paste and product thereof

Abstract

The invention belongs to the field of nanotechnology and electronic manufacturing, and discloses a preparation method of a copper nano-particle soldering paste and a product thereof. The method comprises the following steps that (a), a copper salt and short carbon chain (C3-C5) alcohol ammonia complexing agent is dissolved in a solvent to form a solution, a reducing agent is added into the solution to stir and react sufficiently, and copper nano-particle dispersion liquid is obtained after reaction; and (b), the copper nano-particle dispersion liquid is centrifuged to obtain the copper nano-particles, washing and vacuum drying treatment are carried out, the obtained dried copper nano-particles are dissolved in the copper nano-particle soldering paste in an organic solvent, and vacuum stirring is carried out so as to obtain the required copper nano-particle soldering paste. The invention further discloses the product using the method. According to the method, the prepared copper nano-particle soldering paste is low in cost and good in oxidation resistance, and the particle size distribution of the copper nano-particles in the soldering paste is uniform, and meanwhile, the preparation method is easy to control, low in cost, and simple in process.

Description

technical field [0001] The invention belongs to the field of nanotechnology and electronic manufacturing, and more specifically relates to a preparation method of copper nanoparticle solder paste and its products. Background technique [0002] With the continuous development of system-level high-density integrated packaging and high-power electronic devices, Moore's Law has been seriously challenged, and three-dimensional packaging has become a continuation of Moore's Law with its advantages of high-density integration, miniaturization, low power consumption and low cost. One of the important technical approaches. As we all know, low-temperature bonding technology can provide excellent electrical and thermal channels and mechanical support for three-dimensional packaging, and is one of the key technologies for realizing three-dimensional packaging. At present, lead-containing solder is still widely used in the field of electronic packaging, but the use of lead-containing so...

AI Technical Summary

Problems solved by technology

Although silver nanoparticle solder paste has the advantages of high electrical and thermal conductivity, easy sintering and excellent mechanical properties, the high price and poor resistance to ion migration of silver greatly limit its application prospects.

On the other hand, copper not only has excellent thermal conductivity and electrical conductivity, but also has the advantages of cheap price (about 1 / 100 of the price of silver) and good ion migration resistance, making it one of the ideal low-temperature interconnect materials. Interestingly, copper nanoparticles are chemically active and easily oxidized in the air, and the oxide on the surface will significantly increase the interconnection temperature and reduce the electrical conductivity.

Although organic polymers (polyvinylpyrrolidone, cetylammonium bromide or resin, etc.) coated on the surface of copper nanoparticles can effectively reduce the occurrence of oxidation and agglomeration, they still occur to varying degrees during the preparation and storage process. Oxidation

In addition, the decomposition temperature of the organic polymer coating layer is generally higher than 300 ° C, which is higher than the low-temperature interconnection temperature, so that a large amount of organic matter remains in the bonding layer, which affects the thermal stability and electrical conductivity of the bonding layer

Many researchers further inhibit the oxidation of copper nanoparticles by preparing core-shell nanoparticles (copper-silver, copper-nickel, copper-silica or copper-graphene, etc.), but the preparation process of this core-shell structure is complicated. The cost is higher than that of copper nanoparticles, and the phase separation of the core-shell structure at high temperature will also reduce the conductivity

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