Ni/Au Electroless Plating for Solder Bump Formation in Flip Chip

Flip Chip의 Solder Bump 형성을 위한 Ni/Au 무전해 도금 공정 연구

  • Jo, Min-Gyo (Department of Metallurgical Engineering, Hanyang University) ;
  • O, Mu-Hyeong (Department of Metallurgical Engineering, Hanyang University) ;
  • Lee, Won-Hae (Department of Metallurgical Engineering, Hanyang University) ;
  • Park, Jong-Wan (Department of Metallurgical Engineering, Hanyang University)
  • 조민교 (한양대학교 공과대학 금속공학과) ;
  • 오무형 (한양대학교 공과대학 금속공학과) ;
  • 이원해 (한양대학교 공과대학 금속공학과) ;
  • 박종완 (한양대학교 공과대학 금속공학과)
  • Published : 1996.07.01

Abstract

Electroless plating technique was utilized to flip chip bonding to improve surface mount characteristics. Each step of plating procedure was studied in terms pf pH, plating temperature and plating time. Al patterned 4 inch Si wafers were used as substrstes and zincate was used as an activation solution. Heat treatment was carried out for all the specimens in the temperature range from room temperature to $400^{\circ}C$ for $30^{\circ}C$ minutes in a vacuum furnace. Homogeneous distribution of Zn particles of size was obtained by the zincate treatment with pH 13 ~ 13.5, solution concentration of 15 ~ 25% at room temperature. The plating rates for both Ni-P and Au electroless plating steps increased with increasing the plating temperature and pH. The main crystallization planes of the plated Au were found to be (111) a pH 7 and (200) and (111) at pH 9 independent of the annealing temperature.

Keywords

References

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