科研之友
微信
新浪微博
Facebook
分享链接
摘要
The microstructure and shear strength of joints between Cu-Al2O3 (50 vol.% Al2O3) composite and Cu metal brazed with 72Ag-28Cu and 70Cu-30Zn filler metals were characterized. The composite fabricated by the pulsed electric current sintering of Cu-coated alumina particles showed less than 2% residual porosity and interesting thermophysical properties for electronic packaging applications; thus, the adhesion of the composite to copper metal was evaluated. The composite-Cu assemblies were brazed in an inert atmosphere at working temperatures of 10, 60 and 110 degrees C above the liquidus of the alloys. In the case of Ag-Cu, there was significant diffusion of silver to the composite side, forming a (Ag, Cu) solution. Zinc diffused to the copper side when using the Cu-Zn filler metal, and the formation of fine oxygen-containing Zn precipitates was observed; furthermore, the overheating of the Cu-Zn material originated in interfacial cavities due to evaporation and the zinc deficiency of the fused metal, which reduces its fluidity. The shear strength followed a similar trend with respect to temperature for both joining systems; maximum strengths of 49.9 and 37.1 MPa were obtained for the 72Ag-28Cu and 70Cu-30Zn fillers, respectively, at the intermediate temperatures used. Fracture examination revealed that the brazed arrays failed in all cases on the composite side. The microstructure and strength values indicate a strong adhesion between the parts, which constitutes an important requirement for thermal management in electronic assemblies.
- 出版日期2014-2
