Journal of the Korean Crystal Growth and Crystal Technology (한국결정성장학회지)

The Korea Association of Crystal Growth (한국결정성장학회)
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Microstructure of Sn-Ag-Cu Pb-free solder

Sn-Ag-Cu 무연합금의 미세구조 분석

  • Lee, Jung-Il (Department of Materials Science and Engineering, Korea National University of Transportation) ;
  • Lee, Ho Jun (Department of Materials Science and Engineering, Korea National University of Transportation) ;
  • Yoon, Yo Han (Department of Materials Science and Engineering, Korea National University of Transportation) ;
  • Lee, Ju Yeon (Department of Materials Science and Engineering, Korea National University of Transportation) ;
  • Cho, Hyun Su (Department of Materials Science and Engineering, Korea National University of Transportation) ;
  • Cho, Hyun (Department of Nanomechatronics Engineering, Pusan National University) ;
  • Ryu, Jeong Ho (Department of Materials Science and Engineering, Korea National University of Transportation)
  • 이정일 (한국교통대학교 신소재공학과) ;
  • 이호준 (한국교통대학교 신소재공학과) ;
  • 윤요한 (한국교통대학교 신소재공학과) ;
  • 이주연 (한국교통대학교 신소재공학과) ;
  • 조현수 (한국교통대학교 신소재공학과) ;
  • 조현 (부산대학교 나노메카트로닉스공학과) ;
  • 류정호 (한국교통대학교 신소재공학과)
  • Received : 2017.04.15
  • Accepted : 2017.04.19
  • Published : 2017.04.30
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Abstract

In the past few years, Sn-3.0Ag-0.5Cu (weight%) solder composition has been a representative material to electronic industries as a replacement of Pb-base solder alloy. Therefore, extensive studies on process and/or reliability related with the composition have been reported. However, recent rapid rise in Ag price has demanded solder compositions of low Ag content. In this study, Sn-3.0Ag-0.5Cu solder bar sample was fabricated by melting of Sn, Ag and Cu metal powders. Crystal structure and element concentration were analyzed by XRD, optical microscope, FE-SEM and EDS. The Sn-3.0Ag-0.5Cu solder sample was composed of ${\beta}$-Sn, ${\varepsilon}-Ag_3Sn$ and ${\eta}-Cu_6Sn_5$ phases.

최근 수년 동안 Sn-3.0Ag-0.5Cu(weight%) 조성의 합금은 주요 전자 제조업체들의 대표 무연솔더 조성으로 다양한 전자제품의 제작에 적용되어 왔다. 그러나 최근 Ag 가격의 급격한 상승과 전자산업의 저가격화 전략으로 인해 솔더 재료에서의 Ag 함량의 감소가 지속적으로 요구되고 있다. 본 연구에서는 Sn-3.0Ag-0.5Cu 조성의 무연솔더를 주석, 은 및 구리 금속분말의 용융을 이용하여 합금화 하였다. 제조한 Sn-3.0Ag-0.5Cu 샘플에 대한 결정구조 및 미세구조를 XRD, 광학현미경, FE-SEM 및 EDS 분석을 이용하여 검토하였다. 분석결과, 제조된 Sn-3.0Ag-0.5Cu 샘플은 ${\beta}-Sn$, ${\varepsilon}-Ag_3Sn$ 및 ${\eta}-Cu_6Sn_5$ 결정으로 구성되어 있었다.

Keywords

References

  1. D.R. Frear, "Issues related to the implementation of Pbfree electronic solders in consumer electronics", J. Mater. Sci.-Mater. Electron. 18 (2007) 319.
  2. O. Unal, D.J. Barnard and I.E. Anderson, "A shear test method to measure shear strength of metallic materials and solder joints using small specimens", Scr. Mater. 40 (1999) 271. https://doi.org/10.1016/S1359-6462(98)00432-1
  3. C.M. Miller, E.A. Iver and J.F. Smith, "A viable tin-lead solder substitute: Sn-Ag-Cu", J. Electron. Mater. 23 (1994) 595. https://doi.org/10.1007/BF02653344
  4. A.K. Larsson, L. Stenberg and S. Lidin, "The superstructure of domain-twinned ${\eta}'-Cu_6Sn_5$", Acta Crystallogra. Sect. B-Struct. Sci. 50 (1994) 636. https://doi.org/10.1107/S0108768194004052
  5. J.M. Song, C.F. Huang and H.Y. Chuang, "Crystalliza-tion, morphology and distribution of $Ag_3Sn$ in Sn-Ag- Cu alloys and their influence on the vibration fracture properties", Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. 466 (2007) 9. https://doi.org/10.1016/j.msea.2007.04.121
  6. L.R. Garcia, W.R. Osorio and A. Garcia, "The effect of cooling rate on the dendritic spacing and morphology of $Ag_3Sn$ intermetallic particles of SnAg solder alloys", Mater. Des. 32 (2011) 3008. https://doi.org/10.1016/j.matdes.2010.12.046
  7. D. Swenson, "The effects of suppressed beta tin nucleation on the microstructural evolution of lead-free solder joints", J. Mater. Sci.-Mater. Electron. 18 (2007) 39. https://doi.org/10.1007/s10856-006-0660-2
  8. I.E. Anderson, J.K. Walleser, J.L. Harringa, F Laabs and A. Kracher, "Nucleation control and thermal aging resistance of near-eutectic Sn-Ag-Cu-X solder joints by alloy design", J. Electron. Mater. 38 (2009) 2770. https://doi.org/10.1007/s11664-009-0936-7
  9. C.-M. Chuang and K.-L. Lin, "Effect of microelement addition on the interfacial reaction between Sn-Ag-Cu and the Cu substrate", J. Electron. Mater. 32 (2003) 1426. https://doi.org/10.1007/s11664-003-0111-5
  10. C. Andersson, Z. Lai, J. Liu, H. Jiang and Y. Yu, "Comparison of isothermal mechanical fatigue properties of lead-free solder joints and bulk solders", Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. 394 (2005) 20. https://doi.org/10.1016/j.msea.2004.10.043
  11. K. Suganuma, S.H. Huh, K.S. Kim, H. Nakase and Y. Nakamura, "Effect of Ag content on properties of Sn-Ag binary alloy solder", Mater. Trans. JIM 42 (2001) 286. https://doi.org/10.2320/matertrans.42.286
  12. K.S. Kim, S.H. Huh and K. Suganuma, "Effects of Intermetallic compounds on properties of Sn-Ag-Cu lead-free soldered joints", J. Alloy. Compd. 352 (2003) 226. https://doi.org/10.1016/S0925-8388(02)01166-0
  13. C.W. Hwang and K. Suganuma, "Interface microstructures between Ni-P alloy plating and Sn-Ag-(Cu) leadfree solders", J. Mater. Res. 18 (2003) 2540. https://doi.org/10.1557/JMR.2003.0354
  14. C.W. Hwang, K. Suganuma, M. Kiso and S. Hashimoto, "Influence of Cu addition to interface microstructure between Sn-Ag solder and Au/Ni-6P plating", J. Electron. Mater. 33 (2004) 1200. https://doi.org/10.1007/s11664-004-0123-9
  15. S.W. Kim, J.W. Yoon and S.B. Jung, "Interfacial reactions and shear strengths between Sn-Ag-based Pb-free solder balls and Au/EN/Cu metallization", J. Electron. Mater. 33 (2004) 1182. https://doi.org/10.1007/s11664-004-0121-y
  16. J.W. Yoon, W.C. Moon and S.B. Jung, "Interfacial reaction of ENIG/Sn-Ag-Cu/ENIG sandwich solder joint during isothermal aging", Microelectron. Eng. 83 (2006) 2329. https://doi.org/10.1016/j.mee.2006.10.027
  17. T.C. Chiu and K.L. Lin, "Electromigration behavior of the Cu/Au/SnAgCu/Cu solder combination", J. Mater. Res. 23 (2008) 264. https://doi.org/10.1557/JMR.2008.0036