Korean Journal of Materials Research (한국재료학회지)

Materials Research Society of Korea (한국재료학회)
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Measurement of Adhesion Strength between Oxidized Cu-based Leadframe and EMC

산화처리된 구리계 리드프레임과 EMC 사이의 접착력 측정

  • Lee, Ho-Young (Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology) ;
  • Yu, Jin (Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology)
  • 이호영 (한국과학기술원 재료공학과) ;
  • 유진 (한국과학기술원 재료공학과)
  • Published : 1999.10.01
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Abstract

Due to the inherently poor adhesion strength of Cu-based leadframe/EMC(Epoxy Molding Compound) interface, popcorn-cracking phenomena of thin plastic packages frequently occur during the solder reflow process. In this study, in order to enhance the adhesion strength of Cu-based leadframe/EMC interface, brown-oxide layer was formed on the leadframe surface by immersing of leadframe sheets in hot alkaline solution, and the adhesion strength of leadframe/EMC interface was measured by using SDCB(Sandwiched Double Cantilever Beam) and SBN(Sandwiched Brazil-Nut) specimens. Results showed that brown oxide treatment of leadframe introduced fine acicular CuO crystals on the leadframe surface and improved the adhesion strength of leadframe/EMC interface. Enhancement of adhesion strength was directly related to the thickening kinetics of oxide layer. This might be due to the mechanical interlocking of fine acicular CuO crystals into EMC.

본래 약한 구리계 리드프레임/EMC(Epoxy Molding Compound) 계면의 접착력은 솔더 리플로우 (solder reflow) 공정 중에 종종 박형 플라스틱 패키지의 팝콘 균열 현상(popcorn-cracking phenomena)을 일으킨다. 본 연구에서는 리드프레임/EMC 계면의 접착력을 향상시키기 위하여 리드프레임을 알칼리 용액에 담궈 표면에 brown oxide를 형성시켰으며, EMC로 몰딩(molding)하여 SDCB(Sandwiched Double Cantilever Beam) 시편 및 SBN(Sandwiched Brazil-Nut) 시편을 준비하여 접착력을 측정하였다. 리드프레임의 brown oxide 처리는 미세한 바늘모양의 CuO 결정들을 리드프레임 표면에서 형성시켰으며, 리드프레임/EMC 계면의 접착력을 향상시켰다. 접착력의 향상은 산화층의 평균두께와 직접적인 관련이 있었다. 이는 미세한 바늘모양의 CuO 결정들이 EMC와 기계적인 고착(mechanical interlocking)을 하기 때문으로 생각된다.

Keywords

References

  1. IEEE Trans. on Components, Hybrids, and Manufacturing Technology v.16 G.S.Ganesan;H.M.Berg
  2. IEEE Trans. on Components, Hybrids, and Manufacturing Technology v.16 M.Adachi;S.Ohuchi;N.Totsuka
  3. IEEE Trans. on Components, Packaging, and Manufacturing Technology - Part B : Advanced Packaging v.17 A.A.O.Tay;G.L.Tan;T.B.Lim
  4. IEEE Trans. on Components, Packaging, and Manufacturing Technology - Part A v.17 J.Sauber;L.Lee;S.Hsu;T.Hongsmatip
  5. Proc. IRPS M.Kitano;A.Nishimura;S.Kawai
  6. Proc. 48th Electronic Components and Technology Conf. C.Q.Cui;H.L.Tay;T.C.Chai;R.Gopalakrishan;T.B.Lim
  7. Proc. 48th Electronic Components and Technology Conf. B.H.Moon;H.Y.Yoo;K.Sawada
  8. C.Kembell;Adhesion;D.D.Eley
  9. Proc. 47th Electronic Components and Technology Conf. E.Takano;T.Mino;K.Takahashi;K.Sawada;S.Y.Shimizu;H.Y.Yoo
  10. IEEE Trans. on Components, Packaging, and Manufacturing Technology - Part B v.20 S.J.Cho;K.W.Paik;Y.G.Kim
  11. Proc. 48th Electronic Components and Technology Conf. C.Lee;W.H.sler;H.Cerva;R.von Criegern;A.Parthasarathi
  12. Proc. 48th Electronic Components and Technology Conf. T.Mino;K.Sawada;A.Kuroshi;M.Otsuka;N.Kawamura;H.Y.Yoo
  13. Proc. 49th Electronic Components and Technology Conf. Y.Momioka;J.Miyake
  14. Proc. 49th Electronic Components and Technology Conf. A.A.O.Tay;K.Y.Goh
  15. IBM J. Res. Dev. v.16 W.T.Chen;T.F.Flavin
  16. Int. J. Solid Struc. v.24 K.S.Kim;N.Aravas
  17. Ph. D. thesis, Harvard University Zhigang Suo
  18. ASME J. Applied Mechanics v.54 J.W.Hutchinson;M.E.Mear;J.R.Rice
  19. J. Adhesion v.40 B.J.Love;P.F.Packman
  20. J. Adhesion v.9 J.R.G.Evans;D.E.Packham
  21. J. Electrochem. Soc. v.124 V.Ashworth;D.Fairhurst
  22. Electrochemica Acta. v.55 H.H.Strehblow;B.Titze
  23. Ph. D. thesis, KAIST Ho Young Lee
  24. Materials Science and Engineering v.A107 Z.Suo;J.W.Hutchinson
  25. J. Am. Ceram. Soc. v.70 T.S.Oh;R.M.Cannon;R.O.Ritchie
  26. Int. J. Frac. v.18 C.Atkinson;R.E.Smelser;J.Sanchez
  27. Acta Metall. Mater. v.38 J.S.Wang;Z.Suo
  28. J. Appl. Mech. v.59 K.M.Liechti;Y.S.Chai
  29. Acta Metall v.37 no.3 A.G.Evans;J.W.Hutchinson