Journal of the Microelectronics and Packaging Society (마이크로전자및패키징학회지)

The Korean Microelectronics and Packaging Society (한국마이크로전자및패키징학회)
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Standardization of Bending Impact Test Methods of Sn-Ag-Cu Lead Free Solder Ball

Sn-Ag-Cu계 무연 솔더볼 접합부의 굽힘충격 시험방법 표준화

  • Jang, Im-Nam (Dept. of Materials Sci. & Eng., Pukyong National University) ;
  • Park, Jai-Hyun (Research Institute of Industrial Science & Technology) ;
  • Ahn, Yong-Sik (Dept. of Materials Sci. & Eng., Pukyong National University)
  • 장임남 (부경대학교 신소재공학부) ;
  • 박재현 (포항산업과학연구원) ;
  • 안용식 (부경대학교 신소재공학부)
  • Received : 2010.01.12
  • Accepted : 2010.03.19
  • Published : 2010.03.30
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Abstract

An impact bending test method was used to evaluate the reliability for the solder joint of lead-free solder ball. In order to standardize the test method, the four point impact bending test was applied under the conditions of various frequencies and amounts of +/-amplitude respectively. Effects on the results were analysed. The optimum condition for impact bending test achieved in this study was the frequency of 10 Hz, and the amplitude of (+12/-1)~(+15/-1). 3 kinds of surface finishes Cu-OSP (Organic Solderability Preservative), ENIG (Electroless Nickel Immersion Gold), and ENEPIG (Electroless Nickel, Electroless Palladium, Immersion Gold) were used. Fracture surface showed that cracks were initiated and fractured along the intermetallic layer in the case of surface finishes of Cu-OSP and ENIG, while in the case of ENEPIG the cracks were initiated and propagated in the solder region.

본 연구에서는 무연솔더볼 접합부의 신뢰성평가를 위해 굽힘충격 시험법을 사용하였다. 시험 방법의 표준화를 위하여 시험 시의 주파수, +/-진폭의 크기 등을 각각 변화하여 가면서 각 조건이 결과치에 미치는 영향을 분석하고 굽힘충격 시험을 위한 최적조건을 도출하였다. 굽힘충격 시험을 위한 최적조건은 주파수 10 Hz, 진폭은 (+12/-1)~(+15/-1)의 범위이었다. 시험에 사용된 PCB 표면처리는 Cu-OSP(Organic Solderability Preservative)와 ENIG(Electroless Nickel Immersion Gold) 및 ENEPIG(Electroless Nickel, Electroless Palladium, Immersion Gold)의 3종류를 사용하였고, 솔더 접합계면과 파단면을 관찰한 결과 Cu-OSP와 ENIG의 경우 금속간 화합물 층을 따라서 균열이 발생하여 파단이 일어났으나, ENEPIG의 경우에는 주로 솔더 영역에서만 균열이 생성되고 성장하였다.

Keywords

References

  1. R. Darveaux and A. Syed, "Reliability of area array solder joints in bending", SMTA International Proc. of the technical program, Rosemont, pp.313-324 (2000).
  2. T. Huang and D. Lai, "Reliability and failure analysis of CSP under bending cycle test", Microelectronics Reliability, 47(12), 2197 (2007). https://doi.org/10.1016/j.microrel.2006.10.017
  3. I. N. Jang, J. H. Park and Y. S. Ahn, "Effect of Reflow Number and Surface Finish on the High Speed Shear Properties of Sn-Ag-Cu Lead-Free Solder Bump", J. Microelectron. Packag. Soc., 16(3), 11 (2009).
  4. JEDEC standard JESD22-B113, Board Level Cyclic Bend Test Method for Interconnect Reliability Characterization of Components for Handheld Electronic Products (2006).
  5. MINITAB14 program.
  6. 서순근, "Weibull distribution", MINITAB 신뢰성분석(in Korean), 박준선, 9, pp.52-54, (주)이레테크, (2002).
  7. B. A. Robert, "Failure Distribution", in The New Weibull Handbook, R. B. Abernethy, 4, pp.3-15, RAC, North Palm Beach, Florida (1976).
  8. W. H. Zhu, L. X. Pang, J. H. L. Zhang, X. R. Poh, E. Sun, Y. F. Sun, A. Y. S. Wang and C. K. Tan, "Drop reliability study of PBGA assemblies with SAC305, SAC105 and SAC105-Ni solder ball on Cu-OSP and ENIG surface finish", Proc. 58th Electronic Components and Technology Conference (ECTC), pp.1667-1672 (2008).
  9. 이레테크 Minitab시험팀, "일원 분산분석", 새Minitab 실무완성(in Korean), 5, pp.483-489 (2004).
  10. B. G. Milad and M. orduz, "Surface Finishes in a Lead-Free World", J. circuit world, 34(4), 4 (2008). https://doi.org/10.1108/03056120810918051
  11. Y. S. Park, Y. M. Kwon, H. Y. Son, J. T. Moon, B. W. Jeong, K. I. Kang and K. W. Paik, "A Study of the Interfacial Reaction between Various Sn-Ag-Cu Solder Balls and ENIG (Electroless Ni Immersion Gold) and Cu-OSP (Organic Solderability Preservative) Metal Pad Finish", J. Microelectron. Packag. Soc., 14(4), 45 (2007).
  12. X. X. Lei and W. T. Lee, "Drop Test Failure Analysis of SAC BGA Solder Joints Using Ni/Au and Cu-OSP Pad Finish", Electronic Packaging Technology, 7th International Conference, Shanghai, China, 1-4 (2006).
  13. M. George and G. Don, "Getting the Lead Out of Surface Finishing", Metal Finishing, 104(1), pp.33-36 (2006). https://doi.org/10.1016/S0026-0576(06)80028-0
  14. J. M. Koo, C. Y. Lee and S. B. Jung, "Effect of Reflow Number on Mechanical and Electrical Properties of Ball Grid Array (BGA) Solder Joints", J. Microelectron. Packag. Soc., 14(4), 71 (2007).