Regulation Method Of Silver Surface Nanization And Its Low Temperature Sintering Behavior

With the third-generation semiconductor based on the development of lead-free and high temperature resistant dual requirements for packaging technology and packaging materials more and more high requirements.With the development of silver paste and sintered silver interconnect technology,it has become one of the ideal chip welding technologies,which can replace traditional solder for high temperature application.However,a series of problems,such as the difficult to control silver particle morphology,high synthesis cost,preparation,preservation and process reliability of silver paste,are still the main contradictions in the popularization and application of sintered silver.In order to comply with the development of packaging materials,it is urgent to develop silver particle with controllable morphology and structure and easy to sintering.At the same time,it is necessary to optimize the core formula of silver paste and improve the connection reliability,so as to promote the application of sintered silver in semiconductor packaging technology.Based on the silver particle prepared by chemical method,a small size of silver nanoparticle were prepared in this paper.At the same time,it is found that a multi-scale silver particle is generated,which can reduce the sintering driving force and improve the connection reliability by molecular dynamics simulation.Optimized the above experiment,polyol synthesis method was used to determine the method to prepare the morphology and particle size of the stable and controllable through the control variables,and innovatively nano the surface of the micron silver,that is,the synthesis of the micron silver particles with nano-silver particles growing on the multi-scale silver particles.Under the same experimental conditions,it is found that the morphology growth can be controlled by changing the concentration of chloride ion.With the above three kinds of silver particles with different morphologies as raw materials,through testing the addition of different organic matter,the content of organic matter in silver paste and the selection of organic matter are finally determined.After testing,the final choice is to use ethylene glycol as diluent,add a small amount of binder as the addition of organic matter in silver paste.In order to verify the performance of the silver paste,a vacuum reflux system was used for low temperature sintering.Through the subsequent sintering test,the secondary growth silver particle show good reliability of the connection process,and the shear performance of the sintered joint shows excellent results.In order to solve the problem of heterogeneous interconnection in the connection process,Langmuir-Blodgett film was used in this paper to conduct structural connection between metals and non-metals,and the small particle size nano silver particle prepared above were modified to change the surface properties of non-metals by adhesion to the surface of ceramic substrate through gas-liquid interface,and then interconnect with metals.Through the sintering test,the results show that the method can effectively realize the heterogeneous interconnection between metals and non-metals.