한국표면공학회지 (Journal of the Korean institute of surface engineering)

  • 제50권3호
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  • Pages.170-176
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  • 2017
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  • 1225-8024(pISSN)
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  • 2288-8403(eISSN)
한국표면공학회 (The Korean Institute of Surface Engineering)
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미세피치 플립칩 패키지 구현을 위한 EPIG 표면처리에서의 무전해 팔라듐 피막특성 및 확산에 관한 연구

A Study on Electroless Palladium Layer Characteristics and Its Diffusion in the Electroless Palladium Immersion Gold (EPIG) Surface Treatment for Fine Pitch Flip Chip Package

  • Hur, Jin-Young (Surface R&D Group, Korea institute of industrial technology) ;
  • Lee, Chang-Myeon (Surface R&D Group, Korea institute of industrial technology) ;
  • Koo, Seok-Bon (Surface R&D Group, Korea institute of industrial technology) ;
  • Jeon, Jun-Mi (Surface R&D Group, Korea institute of industrial technology) ;
  • Lee, Hong-Kee (Surface R&D Group, Korea institute of industrial technology)
  • 투고 : 2017.06.27
  • 심사 : 2017.06.28
  • 발행 : 2017.06.30
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초록

EPIG (Electroless Pd/immersion Au) process was studied to replace ENIG (electroless Ni/immersion Au) and ENEPIG (electroless Ni/electroless Pd/immersion Au) processes for bump surface treatment used in high reliable flip chip packages. The palladium and gold layers formed by EPIG process were uniform with thickness of 125 nm and 34.5 nm, respectively. EPAG (Electroless Pd/autocatalytic Au) also produced even layers of palladium and gold with the thickness of 115 nm and 100 nm. TEM results exhibited that the gold layer in EPIG surface had crystalline structure while the palladium layer was amorphous one. After annealing at 250 nm, XPS analysis indicated that the palladium layer with thickness more than 22~33 nm could act as a diffusion barrier of copper interconnects. As a result of comparing the chip shear strength obtained from ENIG and EPIG surfaces, it was confirmed that the bonding strength was similar each other as 12.337 kg and 12.330 kg, respectively.

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