Metallurgical Reactions of Sn-2.5Ag Solder with Various Thicknesses of Electroplated Cu/Ni Under Bump Metallization

• Main Authors: Lin, Yu-Mei, 林育玫
• Other Authors: 陳智
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/66116398235387077658

碩士 === 國立交通大學 === 工學院碩士在職專班半導體材料與製程設備組 === 99 === Cu/Ni has been generally used as an under-bump metallization (UBM) layer in the bumping industry. The purpose of this thesis was investigated in the Sn/Ag interface metallurgy reaction of 97.5wt%Sn-2.5wt%Ag lead-free solder bump between different electroplated Cu layer thickness (5/2/0μm-Cu) and fixed electroplated Ni layer thickness (3μm-Ni). Furthermore the metallurgy interaction and reliability test were also compared of samples with different electroplated Cu layer thickness at thermal aging and re-reflow tests. Experiment results showed that the fracture mode are all internal ductile fracture of Sn/Ag under re-reflow and solid-state aging condition for three kinds of different Cu/Ni thickness and the shear strength could also meet the criteria as well. Please notice that that some items of this experiment are still under reliability and electromigration test. In addition, for 0/3μm Cu/Ni sample, the growth rate constant of Ni3Sn4 is about 0.054μm/hr^1/2 at 150℃ and the consumption rate constant of Ni is about 0.0152μm/hr^1/2 under high temperature storage condition; the growth rate constant of Ni3Sn4 is about 0.228μm/min^1/2 and the consumption rate constant of Ni is about 0.081μm/min^1/2 under re-reflow condition.