Characterization of solder joints made with VPS on DBC substrate

摘要: Ensuring the best quality of solder joint can be crucial in assemblies which operate different environmental conditions, since reliability whole circuit depends on joint. Solder joints a ceramic substrate more prone to cracking because higher stress generated metal layer than is case with simple FR4 substrates. In addition soldering methods like vapour phase or convection have significant influence joint’s mechanical thickness intermetallic layer, number voids, solved compound and precipitations from SAC305 (96.5 %Sn3 %Ag0.5 %) alloy were prepared DCB substrates Al2O3 as base material covered by Cu wiring an Ni/Au preservative coating. Three used, without vacuum option reflow reference. The studied shear strength measurements, 2D 3D X-Ray computed tomography evaluate void formation. fracture surfaces cross-sections optical scanning electron microscopy compare microstructural differences joints. tests carried out showed particular relationships between applied technology