Journal of the Microelectronics and Packaging Society (마이크로전자및패키징학회지)

The Korean Microelectronics and Packaging Society (한국마이크로전자및패키징학회)
권호 표지
DOI QR코드

DOI QR Code

Effects of Solder Particle Size on Rheology and Printing Properties of Solder Paste

미세피치 접합용 솔더 페이스트의 솔더 분말 크기에 따른 레올로지 및 인쇄 특성 평가

  • Jun, So-Yeon (Advanced Joining & Additive Manufacturing R&D Department, Korea Institute of Industrial Technology) ;
  • Lee, Tae-Young (Advanced Joining & Additive Manufacturing R&D Department, Korea Institute of Industrial Technology) ;
  • Park, So-Jeong (Advanced Joining & Additive Manufacturing R&D Department, Korea Institute of Industrial Technology) ;
  • Lee, Jonghun (Advanced Joining & Additive Manufacturing R&D Department, Korea Institute of Industrial Technology) ;
  • Yoo, Sehoon (Advanced Joining & Additive Manufacturing R&D Department, Korea Institute of Industrial Technology)
  • 전소연 (한국생산기술연구원 마이크로조이닝센터 접합적층연구부문) ;
  • 이태영 (한국생산기술연구원 마이크로조이닝센터 접합적층연구부문) ;
  • 박소정 (한국생산기술연구원 마이크로조이닝센터 접합적층연구부문) ;
  • 이종훈 (한국생산기술연구원 마이크로조이닝센터 접합적층연구부문) ;
  • 유세훈 (한국생산기술연구원 마이크로조이닝센터 접합적층연구부문)
  • Received : 2022.06.10
  • Accepted : 2022.06.30
  • Published : 2022.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

The wettability and rheological properties of solder paste with the size of the solder powder were evaluated. To formulate the solder paste, three types of solder powder were used: T4 (20~28 ㎛), T5 (15~25 ㎛), and T6 (5~15 ㎛). The viscosities of the T4, T5, and T6 solder pastes at 10 RPM were 155, 263, and 418 Pa·s, respectively. After 7 days, the viscosity of the T4 solder paste slightly increased by 2.6% and that of T5 was increased by 20.6%. The viscosity of the T6 solder paste after 7 days could not be measured due to high viscosity. The viscosity variation with solder particle size also affected on the printability of the solder. In the case of the T4 solder paste, printability, slump, bridging, and soldering properties were excellent. On the other hand, T5 showed slight dewetting and solder ball defects. Especially, T6, which the smallest powder size, showed poor printability and dewetting at the edge of solder.

본 연구에서는 솔더 분말 크기에 따른 솔더페이스트의 젖음성 및 레올로지 특성을 평가하였다. 솔더페이스트는 T4 (20~28 ㎛), T5 (15~25 ㎛), T6 (5~15 ㎛) 3종류의 Sn-Ag-Cu 합금 분말을 사용하였고, 플럭스와 진공에서 혼합하여 솔더페이스트를 제조하였다. 스파이럴 점도계로 10 rpm의 속도로 측정했을 때 T4, T5, T6 솔더페이스트의 점도는 각각 155, 263, 418 Pa·s의 점도를 보이며, 분말크기가 감소함에 따라 점도는 증가되는 것이 관찰되었다. 또한, 솔더페이스트의 경시변화에 따른 점도변화를 관찰하였으며, 7일 후 T4 솔더페이스트의 경우 점도가 2.6% 증가하여 거의 변화가 없었으나, T5는 20.6%의 증가를 보였으며, T6의 경우 점도 증가가 매우 높아 스파이럴 점도계로는 측정이 불가하였다. 분말 크기에 따른 솔더페이스트 점도 특성은 솔더의 인쇄성에 큰 영향을 주었다. T4 솔더페이스트의 경우 인쇄특성 및 슬럼프와 브릿징 특성이 우수하였지만, 분말 크기가 작은 T5의 경우 인쇄성이 다소 떨어졌으며, T6의 경우 점도가 높아 솔더페이스트가 마스크 개구홀의 벽에 붙고, 따라서 인쇄성이 매우 떨어지는 모습을 보였다. 솔더링을 진행할 경우, T6 솔더페이스트는 디웨팅(dewetting)이 발생하여 젖음성도 T4, T5에 비해 낮은 것이 관찰되었다.

Keywords

Acknowledgement

이 논문은 산업통상자원부 소재부품기술개발사업(과제번호: 20017419)으로 수행되었습니다.

References

  1. G. Beyer, K. Rebibis, A. Podpod, F. Cadacio, T. Wang, A. Miller and E. Beyne, "Packaging and Assembly Challenges for 2.5D/3D Devices", Additional conferences, Device Packaging, HiTEC, HiTEN, and CICMT, (2016).
  2. Y.-C. Hu, Y.-C. Huang, P.-T. Huang, S.-L. Wu, H.-C. Chang, Y.-T. Yang, Y.-H. You, J.-M. Chen, Y-Y. Huang, Y.-H. Lin, J.-R. Duann, T.-W. Chen, W. Hwang, C.-T. Chuang, J.-C. Chiou and K.-N. Chen, "An advanced 2.5-D Heterogeneous Integration Packaging for High-density Neural Sensing Microsystem", IEEE Trans. Electron Devices, 64(4), 1666 (2017). https://doi.org/10.1109/TED.2017.2660763
  3. M. Kawano, "Technology Trends in 2.5 D/3D Packaging and Heterogeneous Integration", 5th IEEE Electron Devices Technology & Manufacturing Conference (EDTM), IEEE, (2021).
  4. J. W. Yoon, J. W. Kim, J. M. Koo, S. S. Ha, B. I. Noh, W. C. Moon, J. H. Moon and S. B. Jung, "Flip-chip bonding technology and reliability of electronic packaging", J. Weld. Join., 25(2), 6 (2007). (in Korean)
  5. J. H. Ahn, K. S. Kim, Y. C. Lee, Y. I. Kim and S. B. Jung, "Regulation in Shear Test Method for BGA of Flip-chip Packages", J. Microelectron. Packag. Soc., 17(3), 1 (2010). (in Korean)
  6. J. M. Kim, J. P. Jung, S. H. Kim and J. H. Park, "Packaging Technology in Electronics and 3- dimensional Stacking Packaging", Journal of KWS, 23(2), 129 (2005). (in Korean)
  7. R. Zhang, Chiong, K. C. Kenny, V. Sureshkumar and L.-S. Chan, "Fine Pitch Solder Paste (T7) for System in Package (SiP) Applications", IEEE 20th Electronics Packaging Technology Conference (EPTC), IEEE, (2018).
  8. T. O'Neill, C. Tafoya and G. Ramirez, "The Impact of Reduced Solder Alloy Powder Size on Solder Paste Print Performance", Proceedings of IPC APEX Expo, (2016).
  9. R. Gray and G. A. Suwanee, "Development of a Robust 03015 Process", Proceedings of IPC APEX Expo, (2015).
  10. B. Roggeman and B. Keser, "Improved SMT and BLR of 0.35mm Pitch Wafer Level Packages", Proceedings of SMTA International, (2015).
  11. S. Harter, J. Franke and C. Lantzsch, "Evaluation of the Stencil Printing for Highly Miniaturized SMT Components with 03015 mm in Size", Proceedings of SMTA International, (2015).
  12. T. Lentz and F. C. T. Assembly, "Size Matters-The Effects of Solder Powder Size on Solder Paste Performance", SMT007 Mag, 32 (2019).
  13. S.-P. Yu, C.-L. Liao, M.-H. Hon and M.-C. Wang, "The Effects of Flux on the Wetting Characteristics of Near-eutectic Sn-Zn-In Solder on Cu Substrate", J. Mater. Sci., 35(17), 4217 (2000). https://doi.org/10.1023/a:1004867329163
  14. E. Bastow, "Does Solder Particle Size Impact the Electrical Reliability of a No-clean Solder Paste Flux Residue", Indium Corp. Tech. Pap., 1 (2017).
  15. A. Nobari and S. St-Laurent, "Effect of Fine and Ultra-fine Lead-free Solder Powder Characteristics on the Reflow Property of Pastes", SMTA Int. Proc., 327 (2016).
  16. Japanese Standards Association, "Japanese Industrial Standard Solder Paste", JIS Z 3284, 1994.
  17. S. S. Zhang, Y. J. Zhang and H. W. Wang. "Effect of Particle Size Distributions on the Rheology of Sn/Ag/Cu Lead-free Solder Pastes", Mater. Des., 31(1) 594 (2010). https://doi.org/10.1016/j.matdes.2009.07.001
  18. O. Krammer, B. Gyarmati, A. Szilagyi, B. Illes, D. Busek and K. Dusek, "The Effect of Solder Paste Particle Size on the Thixotropic Behaviour during Stencil Printing", J. Mater. Process. Technol., 262, 571 (2018). https://doi.org/10.1016/j.jmatprotec.2018.07.027