The Wetting Properties of UBM-coated Si-wafer to the Lead-free Solders in Si-wafer/Bumps/Glass Flip-Chip Bonding System

  • Hong, Soon-Min (School of Materials Science & Engineering, Seoul National University) ;
  • Park, Jae-Yong (School of Materials Science & Engineering, Seoul National University) ;
  • Park, Chang-Bae (Department of Materials Science & Engineering, University of Seoul) ;
  • Jung, Jae-Pil (Department of Materials Science & Engineering, University of Seoul) ;
  • Kang, Choon-Sik (School of Materials Science & Engineering, Seoul National University)
  • 발행 : 2000.04.01

초록

In an attempt to estimate the wetting properties of wettable metal layers by wetting balance method, an analysis of wetting curves of the coating layer was performed. Based on the analysis, wetting properties of UBM-coated Si-plate were estimated by the new wettability indices. The wetting curves of the one and both sides-coated UBM layers have the similar shape and show the similar tendency to the temperature. So the wetting property estimation of one side coating is possible with wetting balance method. For UBM of Si-chip, Cr/Cu/Au UBM is better than Ti/Ni/Au in the point of wetting time. At general reflow temperature, the wettability of high melting point solders(Sn-Sb, Sn-Ag) is better than that of few melting point ones(Sn-Bi, Sn-In).The contact angle of the one side coated plate to the solder can be calculated from the farce balance equation by measuring the static state force and the tilt angle.

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