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Analytical investigation on thermal-induced warpage behavior of ultrathin chip-on-flex (UTCOF) assembly

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Abstract

The serious warpage issues of ultrathin chip-on-flex (UTCOF) assembly induced by mismatched thermal stresses have greatly affected the mechanical stability and reliability of emerging ultrathin chip packaging technology. Currently, a theoretical prediction as a convenient and straightforward approach is still lacked for describing effectively the thermal-mechanical behavior of UTCOF during the adhesive curing and cooling process. In consideration of the adhesive thickness approximating to ultrathin chip and flexible substrate thickness, we develop a layerwise-model of ultrathin chip-adhesive-flex structure under plain strain condition, where the behavior of thick adhesive bonding can be described precisely through increasing the subdivided mathematical plies. Further, the analytical results show that the concave and convex forms of ultrathin chip warpage yield at the end of the curing and cooling process respectively. Meanwhile, the effects of its structure dimensions and material properties are also revealed for discussing a way to relieve the extent of ultrathin chip warpage. Additionally, in order to verify the validity of the theoretical prediction, we also introduce the corresponding numerical technique and experimental method. These results suggest that a kind of rigid and ultrathin flexible substrate such as metal foil should be adopted for small warpage of ultrathin assembly.

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References

  1. Marks M R, Hassan Z, Cheong K Y. Ultrathin wafer pre-assembly and assembly process technologies: A review. Critical Rev Solid State Mater Sci, 2015, 40: 251–290

    Article  Google Scholar 

  2. Rogers J, Lagally M, Nuzzo R. Synthesis, assembly and applications of semiconductor nanomembranes. Nature, 2011, 477: 45–53

    Article  Google Scholar 

  3. Burghartz J. Ultra-Thin Chip Technology and Applications. Springer: Berlin, 2011

    Book  Google Scholar 

  4. Jeon E B, Park J D, Song J H, et al. Bi-axial fracture strength characteristic of an ultra-thin flash memory chip. J Micromech Microeng, 2012, 22: 105014

    Article  Google Scholar 

  5. Endler S, Rempp H, Harendt C, et al. Compensation of externally applied mechanical stress by stacking of ultrathin chips. Solid-State Electron, 2012, 74: 102–107

    Article  Google Scholar 

  6. Lu S T, Lin Y M, Chuang C C, et al. Development of a novel compliant- bump structure for ACA-bonded chip-on-flex (COF) interconnects with ultra-fine pitch. IEEE Trans Compon, Packag, Manuf Tech, 2011, 1: 33–42

    Article  Google Scholar 

  7. Hassan M U, Angelopoulos E A, Rempp H, et al. Packaging challenges associated with warpage of ultra-thin chips. In: Peoceedings of 3rd Electronic System-Integration Technology Conference (ESTC), Berlin: IEEE, 2010

  8. Lu S T, Chen W H. Reliability and flexibility of ultra-thin chip-on-flex (UTCOF) interconnects with anisotropic conductive adhesive (ACA) joints. IEEE Trans Adv Packag, 2010, 33: 702–712

    Article  Google Scholar 

  9. Yang S Y, Kwon W S, Lee S B. Chip warpage model for reliability prediction of delamination failures. Microelectron Rel, 2012, 52: 718–724

    Article  Google Scholar 

  10. Liu Y. Trends of power semiconductor wafer level packaging. Microelectron Rel, 2010, 50: 514–521

    Article  Google Scholar 

  11. Tu K N. Reliability challenges in 3D IC packaging technology. Microelectron Rel, 2011, 51: 517–523

    Article  Google Scholar 

  12. Cheng H C, Chen W H, Lin C S, et al. On the thermal-mechanical behaviors of a novel nanowire-based anisotropic conductive film technology. IEEE Trans Adv Packag, 2009, 32: 546–563

    Article  Google Scholar 

  13. Cheng H C, Huang H H, Chen W H, et al. Hygro-thermo-mechanical behavior of adhesive-based flexible chip-on-flex packaging. J Electron Mater, 2015, 44: 1220–1237

    Article  Google Scholar 

  14. Cheng H C, Ma C H, Yu C F, et al. Process-dependent thermal- mechanical behaviors of an advanced thin-flip-chip-on-flex interconnect technology with anisotropic conductive film joints. CMC: Comput, Mater Contin, 2013, 38: 129–154

    Google Scholar 

  15. Lu S T, Chen W H. Experimental/numerical analysis of thermally induced warpage of ultrathin chip-on-flex (utcof) interconnects. IEEE Trans Compon Packag Tech, 2010, 33: 819–829

    Article  Google Scholar 

  16. Suhir E. Analysis of interfacial thermal stresses in a trimaterial assembly. J Appl phys, 2001, 89: 3685–3694

    Article  Google Scholar 

  17. Tsai M Y, Hsu C H, Han C N. A note on suhir’s solution of thermal stresses for a die-substrate assembly. J Electron Packag, 2004, 126: 115–119

    Article  Google Scholar 

  18. Wang K, Huang Y, Chandra A, et al. Interfacial shear stress, peeling stress, and die cracking stress in trilayer electronic assemblies. In: Proceedings of 7th intersociety Conference On Thermal And Thermomechanical Phenomena In Electronic Systems. Las Vegas: IEEE, 2000

    Google Scholar 

  19. Tsai M Y, Chang H Y, Pecht M. Warpage analysis of flip-chip PBGA packages subject to thermal loading. IEEE Trans Device Mater Rel, 2009, 9: 419–424

    Article  Google Scholar 

  20. Xu Z, Liu Z, Huang Y, et al. Vacuum-based picking-up of thin chip from adhesive tape. J Adhesion Sci Tech, 2015, 29: 1315–1329

    Article  Google Scholar 

  21. Xu Z, Liu Z, Liu H, et al. Analytical evaluation of interfacial crack propagation in vacuum-based picking-up process. IEEE Trans Compon, Packag, Manuf Tech, 2015, 5: 1700–1708

    Article  Google Scholar 

  22. Wacker N, Richter H, Hoang T, et al. Stress analysis of ultra-thin silicon chip-on-foil electronic assembly under bending. Semicond Sci Tech, 2014, 29: 095007

    Article  Google Scholar 

  23. Yousefsani S A, Tahani M. Accurate determination of stress distributions in adhesively bonded homogeneous and heterogeneous double- lap joints. Eur J Mech A, 2013, 39: 197–208

    Article  MathSciNet  Google Scholar 

  24. Yousefsani S A, Tahani M. An analytical investigation on thermomechanical stress analysis of adhesively bonded joints undergoing heat conduction. Arch Appl Mech, 2014, 84: 67–69

    Article  MATH  Google Scholar 

  25. Abdolmajid Y S, Tahani M. Analytical solutions for adhesively bonded composite single-lap joints under mechanical loadings using full layerwise theory. Int J Adhes Adhes, 2013,43: 32–41

    Article  Google Scholar 

  26. Reddy J N. A generalization of two-dimensional theories of laminated composite plates. Commun Appl Numer Methods, 1987, 3: 173–180

    Article  MATH  Google Scholar 

  27. Tahani M, Yousefsani S A. On thermomechanical stress analysis of adhesively bonded composite joints in presence of an interfacial void. Compos Struct, 2015, 130: 116–123

    Article  Google Scholar 

  28. Yao Q, Qu J. Three-dimensional versus two-dimensional finite element modeling of flip-chip packages. J Electron Packag, 1999, 121: 196–201

    Article  Google Scholar 

  29. Zhao J H, Dai X, Ho P S. Analysis and modeling verification for thermal-mechanical deformation in flip-chip packages. In: Proceedings of the 48th Electronic Components and Technology Conference. Seattle: IEEE, 1998

  30. Nosier A, Kapania R K, Reddy J. Free vibration analysis of laminated plates using a layerwise theory. AIAA J, 1993, 31: 2335–2346

    Article  MATH  Google Scholar 

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Authors and Affiliations

  1. State Key Laboratory of Digital Manufacturing Equipment and Technology, Flexible Electronics Research Center, Huazhong University of Science and Technology, Wuhan, 430074, China

    JianKui Chen, ZhouLong Xu, YongAn Huang, YongQing Duan & ZhouPing Yin

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  1. JianKui Chen
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  2. ZhouLong Xu
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  3. YongAn Huang
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  4. YongQing Duan
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  5. ZhouPing Yin
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Correspondence to ZhouLong Xu.

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Chen, J., Xu, Z., Huang, Y. et al. Analytical investigation on thermal-induced warpage behavior of ultrathin chip-on-flex (UTCOF) assembly. Sci. China Technol. Sci. 59, 1646–1655 (2016). https://doi.org/10.1007/s11431-016-0588-6

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  • DOI: https://doi.org/10.1007/s11431-016-0588-6

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