DOI QR코드

DOI QR Code

Brittle Fracture Behavior of ENIG/Sn-Ag-Cu Solder Joint with pH of Ni-P Electroless Plating Solution

무전해 니켈 도금액 pH 변화에 따른 ENIG/Sn-Ag-Cu솔더 접합부의 취성파괴 특성

  • Seo, Wonil (Joining R&D Group, Korea Institute of Industrial Technology) ;
  • Lee, Tae-Ik (Joining R&D Group, Korea Institute of Industrial Technology) ;
  • Kim, Young-Ho (Division of Materials Science and Engineering, Hanyang University) ;
  • Yoo, Sehoon (Joining R&D Group, Korea Institute of Industrial Technology)
  • 서원일 (한국생산기술연구원 부품기능연구부문) ;
  • 이태익 (한국생산기술연구원 부품기능연구부문) ;
  • 김영호 (한양대학교 신소재공학부) ;
  • 유세훈 (한국생산기술연구원 부품기능연구부문)
  • Received : 2019.12.12
  • Accepted : 2020.09.02
  • Published : 2020.09.30

Abstract

The behavior of brittle fracture of electroless nickel immersion gold (ENIG) /Sn-3.0wt.%Ag-0.5wt.%Cu (SAC305) solder joints was evaluated. The pH of the electroless nickel plating solution for ENIG surface treatment was changed from 4.0 to 5.5. As the pH of the Ni plating solution increased, pin hole in the Ni-P layer increased. The thickness of the interfacial intermetallic compound (IMC) of the solder joint increased with pH of Ni plating solution. The high speed shear strength of the SAC305 solder joint on ENIG surface finish decreased with the pH of the Ni plating solution. In addition, the brittle fracture rate of the solder joint was the highest when the pH of the Ni plating solution was 5.

본 연구에서는 무전해 니켈 도금액 pH 변화에 따른 electroless nickel immersion gold (ENIG)/Sn-3.0wt.%Ag-0.5wt.%Cu(SAC305) 솔더 접합부 취성 파괴 거동에 대하여 평가하였다. ENIG 표면처리를 위한 무전해 니켈 도금액의 pH는 4.0에서 5.5로 변화 시켰다. 무전해 니켈 도금 후 Ni-P 표면 관찰 결과, 도금액의 pH가 낮아질수록 Ni-P 층 nodule 표면에 핀홀이 증가하였다. 솔더링 후 접합부 계면에서는 (Cu,Ni)6Sn5 금속간화합물이 형성되었으며, 무전해 니켈 도금액의 pH가 증가할수록 솔더접합부의 계면 금속간화합물의 두께는 증가하였다. 고속전단 시험을 통하여 ENIG/SAC305 솔더 접합부의 취성파괴 거동을 확인하였으며, 무전해 니켈 도금액의 pH가 증가할수록 솔더접합부의 전단강도는 감소하는 경향을 보였다. 또한, 솔더 접합부의 취성 파괴율은 pH가 5일 때 가장 높은 값을 보였다.

Keywords

References

  1. C. E. Ho, C. W. Fan, and W. Z. Hsieh, "Pronounced effects of Ni(P) thickness on the interfacial reaction and high impact resistance of the solder/Au/Pd(P)/Ni(P)/Cu reactive system", Surf. Coatings Technol., 259(PB), 244 (2014). https://doi.org/10.1016/j.surfcoat.2014.04.027
  2. C. Y. Ho and J. G. Duh, "Optimal Ni(P) thickness design in ultrathin-ENEPIG metallization for soldering application concerning electrical impedance and mechanical bonding strength", Mater. Sci. Eng. A, 611, 162, (2014). https://doi.org/10.1016/j.msea.2014.05.049
  3. P. Snugovsky, P. Arrowsmith, and M. Romansky, "Electroless Ni/immersion Au interconnects: Investigation of black pad in wire bonds and solder joints", J. Electron. Mater., 30(9), 1262 (2001). https://doi.org/10.1007/s11664-001-0159-z
  4. J. Back, B. Lee, S. Yoo, D. Han, S. Jung, and J. Yoon, "Solderability of thin ENEPIG plating Layer for Fine Pitch Package application", J. Microelectron. Packag. Soc., 24(1), 83 (2017). https://doi.org/10.6117/kmeps.2017.24.1.083
  5. S. Lamprecht and P. Backus, "High Phosphorus ENIG - highest resistance against corrosive environment Sven Lamprecht and Petra Backus Atotech Deutschland GmbH Berlin", HKPCA J., Q4(6), 1 (2002).
  6. S. H. Kim, J. M. Kim, S. Yoo, and Y. B. Park, "Effects of surface finishes and current stressing on the interfacial reaction characteristics of Sn-1.2Ag-0.7Cu-0.4In solder bumps", Curr. Appl. Phys., 13(2), S103 (2013). https://doi.org/10.1016/j.cap.2013.01.002
  7. T.-Y. Lee, M.-S. Kim, E.-S. Ko, J.-H. Choi, M.-G. Jang, M.- S. Kim, and S. H. Yoo, "Properties of High Power Flip Chip LED Package with Bonding Materials", J. Microelectron. Packag. Soc., 21(1), 1 (2014). https://doi.org/10.6117/kmeps.2014.21.1.001
  8. W. Seo, K. H. Kim, J. H. Bang, M. S. Kim, and S. Yoo, "Effect of Bath Life of Ni(P) on the Brittle-Fracture Behavior of Sn-3.0Ag-0.5Cu/ENIG", J. Electron. Mater., 43(12), 4457 (2014). https://doi.org/10.1007/s11664-014-3395-8
  9. H. Lee, J. Jung, C. Heo, C. Kim, J. H. Lee, and Y. Kim, "Characterization of the Contamination Factor of Electroless Ni Plating Solutions on the ENIG Process", J. Electron. Mater., 47(9), 5158 (2018). https://doi.org/10.1007/s11664-018-6335-1
  10. M. O. Alam, Y. C. Chan, and K. C. Hung, "Reliability study of the electroless Ni-P layer against solder alloy", Microelectronics Reliability, 42(7), 1065 (2002). https://doi.org/10.1016/S0026-2714(02)00068-9
  11. W. Seo, K. H. Kim, Y. H. Kim, and S. Yoo, "Effect of Ni-P Plating Temperature on Growth of Interfacial Intermetallic Compound in Electroless Nickel Immersion Gold/Sn-Ag-Cu Solder Joints", J. Electron. Mater., 47(1), 110 (2018).
  12. K. Kim, W. Seo, S.-H. Kwon, J.-K. Kim, J.-W. Yoon, and S. Yoo, "Effects of Ni-P Bath on the Brittle Fracture of Sn-Ag-Cu Solder/ENEPIG Solder Joint", Journal of Welding and Joining, 35(3), 1 (2017).
  13. D. J. Lee and H. S. Lee, "Major factors to the solder joint strength of ENIG layer in FC BGA package", Microelectron. Reliab., 46(7), 1119 (2006). https://doi.org/10.1016/j.microrel.2005.08.006
  14. Y.-C. Sohn and J. Yu, "Correlation between Interfacial Reaction and Brittle Fracture Found in", J. Microelectron. Packag. Soc., 12(1), 41 (2005).
  15. H. Lee, S. Lee, K. Kim, C. Heo, J. H. Lee, and Y. Kim, "Investigation of surface defects of electroless Ni plating by solder resist dissolution on the ENIG process", Microelectron. Eng., 200, 39 (2018). https://doi.org/10.1016/j.mee.2018.06.001
  16. B. K. Kim, S.-J. Lee, J.-Y. Kim, K.-Y. Ji, Y.-J. Yoon, M.-Y. Kim, S.-H. Park, and J.-S. Yoo, "Origin of surface defects in PCB final finishes by the electroless nickel immersion gold process", J. Electron. Mater., 37(4), 527 (2008). https://doi.org/10.1007/s11664-007-0360-9
  17. J. Osenbach, A. Amin, F. Baiocchi, and J. Delucca, "ENIG corrosion induced by second-phase precipitation", J. Electron. Mater., 38(12), 2592 (2009). https://doi.org/10.1007/s11664-009-0938-5
  18. Y. C. Sohn and J. Yu, "Correlation between chemical reaction and brittle fracture found in electroless Ni(P)/immersion goldsolder interconnection", J. Mater. Res., 20(8), 1931 (2005). https://doi.org/10.1557/JMR.2005.0246
  19. M. O. Alam and Y. C. Chan, "Effect of reaction time and P content on mechanical strength of the interface formed between eutectic Sn-Ag solder and Au/electroless Ni (P)/Cu bond pad", 94(6), 4108 (2003). https://doi.org/10.1063/1.1602563
  20. J. W. Yoon, J. H. Park, C. C. Shur, and S. B. Jung, "Characteristic evaluation of electroless nickel-phosphorus deposits with different phosphorus contents", Microelectron. Eng., 84(11), 2552 (2007). https://doi.org/10.1016/j.mee.2007.05.057
  21. I. Baskaran, T. S. N. S. Narayanan, and A. Stephen, "Effect of accelerators and stabilizers on the formation and characteristics of electroless Ni-P deposits", Mater. Chem. Phys., 99(1), 117 (2006). https://doi.org/10.1016/j.matchemphys.2005.10.001
  22. T. Hentschel, D. Isheim, R. Kirchheim, F. Muller, and H. Kreye, "Nanocrystalline Ni-3.6 at.% P and its transformation sequence studied by atom-probe field-ion microscopy", Acta Mater., 48(4), 933 (2000). https://doi.org/10.1016/S1359-6454(99)00371-7
  23. K. Pun and C. Q. Cui, "Enhancement of TBGA substrate in packing drop test", Proc. 2009 International Conference on Electronic Packaging Technology & High Density Packaging (ICEPT-HDP) Beijing, China, 2, 1097 (2009).