The Effect Of Technological Parameters On Electromagnetic Suppression Molding Of Welding Property Of High Tin Containing N Indium Silver Based Brazing Filler Metal

Brazing is an important part of modern welding technology and a common technique for microelectronic packaging.The metal-based brazing filler metal has the advantages of the matrix material,and can also fully utilize the excellent characteristics of each component by adjusting the type and content of the component,and has broad application prospects.Among them,silver-based solders are widely used in the market due to their low melting point,good electrical conductivity,high strength and strong spreading ability.In this paper,in view of the difficulties in the processing of brazing filler metal,electromagnetic pressing technology combined with powder metallurgy technology is used to make silver-based brazing filler metal.In this paper,high-tin indium-containing silver-based solder57.6Ag-22.4Cu-15Sn-5In was used as the research object.The ball-milled mixed powder was made into compact by electromagnetic pressing method,and the compact was analyzed at different voltage values and capacitance values.The trend of density is obtained,and the optimal discharge parameters are obtained.The liquid phase sintering experiment was carried out on the compact in the SG-GL1200L horizontal tube furnace,and the solder foil with different sintering parameters was obtained and brazed experiments were carried out.The brazed joint was made into a metallographic sample,and SEM microstructure observation,XRD diffraction phase analysis,peel strength test,electron probe element content analysis and the like were performed to analyze the sintering temperature and sintering time on the brazed joint mechanics.The effect of performance and microstructure morphology,obtaining the best production process parameters,preparing environmentally friendly brazing fillers with excellent comprehensive performance,and comparing performance with silver-based brazing fillers widely used in the market to ensure 57.6Ag-22.4Cu-15Sn-5In silver-based solder has production value and provides valuable theoretical basis and practical guidance for electromagnetic pressing to prepare environmentally friendly brazing materials.In the process of electromagnetic pressing,the pulse width has a significant influence on the pressing process.The specific performance is as follows:when the capacitance value?the pulse width?is constant,the density of the compact increases significantly with the increase of the voltage value?the pulse amplitude?;The voltage value is constant,and as the capacitance value increases,the density of the green compact increases slightly.During the sintering process,when the holding time is constant,the microhardness of the welded joint increases and the peeling strength increases with the increase of the sintering temperature;When the sintering temperature is constant,the microhardness of the welded joint decreases and the peeling strength decreases with the increase of the holding time.During the brazing process,the brazing filler metal foil is melted to a liquid state and then filled with the parent material gap under the capillary force and diffused toward the center of the weld.The liquid brazing material undergoes a metallurgical reaction with the base metal to form a high strength phase of Cu₄In,thus microhardness of the brazed zone is the highest,and the grain in the heat-affected zone is coarse,resulting in a decrease in microhardness.Therefore,the microhardness of the joint gradually increases from the base metal zone to the heat-affected zone to the brazed zone.The type and content of the phase have a direct effect on the mechanical properties of the joint.Both In and Sn can be dissolved in the copper-rich phase of the brazing filler metal to form a solid solution,and an intermetallic compound Cu₄In,Cu_40.5Sn₁₁ or the like is produced.With the increase of sintering temperature,the content of Cu4In in the high strength phase increases gradually,and the mechanical properties of the brazed joint increase.With the prolongation of the sintering holding time,resulting in the brittle phase Cu₃Sn,resulting in brazing.The mechanical properties of the joint are reduced,and even defects such as cracks appear.Reasonable sintering parameters are necessary for controlling the brazing filler metal phase and obtaining a high performance brazed joint.