마이크로전자및패키징학회지 (Journal of the Microelectronics and Packaging Society)

  • 제18권2호
  • /
  • Pages.49-55
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  • 2011
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  • 1226-9360(pISSN)
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  • 2287-7525(eISSN)
한국마이크로전자및패키징학회 (The Korean Microelectronics and Packaging Society)
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시효처리한 Sn-xAg-Cu계 무연솔더 조성에 따른 굽힘충격 특성평가

Bending Impact Properties Evaluation of Sn-xAg-Cu Lead Free Solder Composition and aging treatment

  • 장임남 (부경대학교 신소재공학부) ;
  • 박재현 (포항산업과학연구원) ;
  • 안용식 (부경대학교 신소재공학부)
  • Jang, Im-Nam (Dept. of Materials Sci. & Eng., Pukyong National University) ;
  • Park, Jai-Hyun (Research Institute of Industrial Science & Technology, Pohang) ;
  • Ahn, Yong-Sik (Dept. of Materials Sci. & Eng., Pukyong National University)
  • 투고 : 2011.04.20
  • 심사 : 2011.06.23
  • 발행 : 2011.08.31
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초록

전자기기에서의 고장 중 대부분은 작동 중 발생하는 열과 충격에 기인한다. 이 열과 충격은 PCB(Printed Board) 부품의 접합부 계면에 균열을 야기 시키고, 이 균열은 금속간 화합물(Intermetallic Compound: IMC)의 형성과 밀접한 관계를 가진다. 본 연구에서는 Sn-Ag-Cu계의 Ag함량을 변화한 Sn-1.0Ag-0.5Cu와 Sn-1.2Ag-0.5Cu 및 Sn-3.0Ag-0.5Cu의 3가지 조성의 솔더로 접합한 소재를 대상으로 1000시간 까지 등온시효(Isothermal Aging) 하였다. 등온시효 동 안 솔더(Solder)의 계면에 발생하는 IMC(Intermetallic Compound) 성장이 관찰되었으며, solder 접합부의 기계적 특성은 굽힘충격 시험법을 이용하여 평가되었다. 그 결과 시효처리 전에는 Ag 함량이 낮은 solder의 굽힘충격 특성이 우수하게 나타났으나, 시효처리 후에는 반대의 결과를 나타내었다. 이 결과는 IMC layer 주변에 생성된 미세한 $Ag_3Sn$ 및 조대한 $Cu_6Sn_5$와 관련되어, 미세한 $Ag_3Sn$이 충격을 완화한 것으로 나타나 이에 따라 굽힘충격 특성에 차이가 나타남을 알 수 있었다.

The failure of electronic instruments is mostly caused by heat and shock. This shock causes the crack initiation at the solder joint interface of PCB component which is closely related with the formation of intermetallic compound(IMC). The Ag content in Pb-free Sn-xAg-0.5Cu solder alloy used in this study was 1.0, 1.2 and 3.0 wt.%, respectively. After soldering with PCB component, isothermal aging was performed to 1000 hrs. The growth of IMC layer was observed during isothermal aging. The drop impact property of solder joint was evaluated by impact bending test method. The solder joint made with the solder containing lower Ag content showed better impact bending property compared with that with higher Ag content. On the contrary to this result, the solder joint made with solder containing higher Ag content showed better impact bending property after aging. It should be caused by the formation of fine $Ag_3Sn$, which relieved the impact. It showed consequently the different effect of fine $Ag_3Sn$ and coarse $Cu_6Sn_5$ particles formed in the IMC layer on the impact bending property.

키워드

참고문헌

  1. JEDEC Standard JESD22-B111, Board Level Drop test Method of Composnents for Handheld Electronic Products.(2006)
  2. I. N. Jang, J. H. Park and Y. S. Ahn, "Standardization of Bending Fatigue Impact test Method of Sn-Ag-Cu Lead-Free Solder Ball", J. Microelectron. Packag. Soc., 17(1), 55 (2010).
  3. S. G. Seo, "Weibull distribution", MINITAB Reliability analysis (in Kor.), J. S. Park, 9, pp.52-54, (Cop.)Ireatech, (2002).
  4. I. N. Jang, J. H. Park and Y. S. Ahn, "Mechanical Characteristic Evaluation of Sn-Ag-Cu Lead Free Solder Ball Joint on The Pad Geometry", J. Microelectron. Packag. Soc., 17(2), 41 (2010).
  5. J. S. Jeong, Y. S. Lee, K. H. Shin, S. K. Cheong, D. Y. Jang, "A Study on the Failure Characteristics of Sn-xAg-0.5Cu Lead-Free Solder Balls", J. Kor. Soc. Machine Tool Eng., 18(5), 449 (2009).
  6. T. C. Chang, M. C. Wang, M. H. Hon "Effect of Ag addition on the structures of intermetallic compounds and the adhesion strength of the Sn-9Zn-xAg/Cu interface", Journal of Crystal Growth, 252, 391 (2003). https://doi.org/10.1016/S0022-0248(02)02479-X
  7. W. H. Zhu, L. X Pang, J. H. L. Zhang, X. R. Poh, E. Sun, Y. F. Sun, A. Y. S. Wang, C. K. Tan, H. B. "Drop reliability study of PBGA assemblies with SAC305, SAC105 and SAC105-Ni solder ball on Cu-OSP and ENIG surface finish", Electronic Components and Technology Conference, ECTC 2008. 58th. Volume, Issue, 27-30, pp.1667-1672 (2008).
  8. 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).
  9. W. S. Hong, C. M. Oh, "Thermal Shock Reliability of Low Ag Composition Sn-3.0Ag-0.5Cu Pb-free Solder Joints", J. Kor. Inst. Met. & Mater., 47(12), 842 (2009).
  10. C. H. Yu, K. S. Kim, "Thermal Cycling Analysis of Flip-Chip BGA Solder Joints", J. Microelectron. Packag. Soc., 10(1), 45 (2003).