Ag-cu-p-ge Series In Electronic Packaging Temperature Brazing Study Of The Production Process And Organizational Performance

The silver-based solder for electronic packaging Materials was researched in this article. The nine compositions of silver-based solder alloy for melting temperature between 550 and 650℃are designed, the solder is made by rolling process. Melting characteristics was analyzed by differential scanning Calorimeter (DSC). Phase composition, microstructure and morphology are characterized by X-ray diffraction (XRD), metallographic microscope, scanning electron microscopy (SEM), respectively. The fluidity, wetting and mechanical property of the solder are researched. The main conclusions are as follows:(1) The processing performance, melting characteristics and mechanical properties of the solder of silver-based alloy are tested. The experimental results shows that Ag23.9Cu70.1P5.6Ge0.4 is the best solder alloy. Its solidus and liquids temperatures are 646℃and 661℃, respectively. The appropriate amount of P, Ge and other elements are added in the solder, which could reduce the melting point of alloy and reduce interval of the solid-liquid phase. The welding and machining performance is excellent.(2)The microstructure and morphology of Ag23.9Cu70.1 P5.6Ge0.4 is analyzed by scanning electronic morphology and energy spectrum. The organization of the solder alloy is as follows: the alloy is composed of a solid solution phase of Ag-rich with faced cubic structure andβsolid solution phase of Cu-rich with complicated structure. The alloy is composed of the Ag-rich white early phase Ag, (αandβ) dual eutectic and (αandβand Cu3 P) ternary eutectic, Ge is a freely state in the organization.(3) After the coarse grain of solder alloy is hot-rolled, the grain turns is smaller than before, the organization is extended along the main direction of deformation. The fibrous organization is formed by cold-rolling .The thin strip about 0.2-0.4mm is produced by reasonable production process. (4) When the liquid temperature is above the 30℃and 50℃, the solder alloy can spread out fully on the copper plate and possesses excellent flowability and wettability.(5)The tensile strength of the Ag23.9Cu70.1P5.6 solder alloy is 335MPa.The tensile fracture of the solder alloy appearances Fibrous in macroscopic, Shear strength of the weld is 154MPa.The quality of the weld is excellent. The microstructure shows oval-shaped dimples. Analyzed by scanning electron microscopy, the fracture has the characteristic of gliding fracture...