Abstract
The use of NCAs to form direct contact interconnections between chip bumps and substrate pads have become a viable option in interconnection technology for fine-pitch applications. However, the primary concerns with NCAs are their long-term reliability, stability, and consistent electrical performance in particulate interconnections. Results of assembly process studies and environmental testing using NCAs on flexible substrates are analyzed and discussed herein. An extensive design experiment was performed to determine which process parameters were critical in obtaining good electrical connections. A reliability evaluation of NCAs for flexible substrate applications was carried out to gain more insight into the failure mechanisms of this type of interconnect. Pressure cooker test results showed that failures occurring in NCA joints are primarily due to moisture absorption, which could lead to interfacial delamination at the substrate/adhesive interface, accompanied by hygroscopic swelling. NCAs with lower coefficients of thermal expansion also exhibited better contact resistance stability during high-temperature storage tests.
Similar content being viewed by others
References
R. Haug, U. Behner, C.-P. Czaya, H.-J. Jiang, K. Stefan, S. Reiner, and C.P.O. Treuteler, IEEE Trans. Electron. Packaging 23, 12 (2000).
H. Kristiansen and J. Liu, IEEE Trans. Compon. Packaging, Part A 21, 208 (1998).
S. Liong, C.P. Wong, and W.F. Burgoyne, IEEE Trans. Compon. Packaging Technol. 28, 327 (2005).
D. Klosterman, L. Li, and J.E. Morris, IEEE Trans. Compon. Packaging, Part A 21, 23 (1998).
S.H. Mannan, D.C. Whalley, A.O. Ogunjimi, and D.J. Williams, International Symposium on Electronic Manufacturing Technology (Piscataway, NJ: IEEE, 1995), pp. 142–145.
H. Kristiansen and A. Bjorneklett, J. Electron. Manuf. 2, 7 (1992).
J. Vanfleteren, B. Vandecasteele, and T. Podprocky, Electronics Packaging Technology Conference (Piscataway, NJ: IEEE, 2002), pp. 139–143.
J.C. Jagt, IEEE Trans. Compon. Packaging, Part A 21, 215 (1998).
D.E. Pachucki, IEEE Trans. Compon. Packaging, Part A 18, 3 (1995).
H.C. Cheng, C.L. Ho, K.N. Chiang, and S.M. Chang, IEEE Trans. Compon. Packaging Technol. 27, 398 (2004).
W.K. Chiang and Y.C. Chan, J. Electron. Packag. 127, 113 (2005).
L. Cao, Z. Lai, and J. Liu, Proceedings of the Sixth IEEE CPMT Conference on High-Density Microsystem Design and Packaging and Component Failure Analysis (Piscataway, NJ: IEEE, 2004), pp. 254–258.
R.H. Estes, International Symposium on Advanced Packaging Materials: Processes, Properties and Interfaces (Piscataway, NJ: IMAPS, IEEE, 2000), pp. 1–6.
L.L. Mercado, J. White, V. Sarihan, and T.-Y.T. Lee, IEEE Trans. Compon. Packaging Technol. 26, 509 (2003).
K.W. Paik, M.J. Yim, and Y.-D. Jeon, Proceedings of 3rd Electronics Packaging Technology Conference (Piscataway, NJ: IEEE, 2000), pp. 378–384.
R. Dudek, A. Schubert, and B. Michel IV, International Conference on Adhesive Joining and Coating Technology in Electronics Manufacturing Proceedings (Piscataway, NJ: IEEE, 2000), pp. 77–85.
M.J. Yim and K.W. Paik, IEEE Trans. Adv. Packaging 22, 166 (1999).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Chiang, W.K., Chan, Y.C., Ralph, B. et al. Processability and reliability of nonconductive adhesives (NCAs) in fine-pitch chip-on-flex applications. J. Electron. Mater. 35, 443–452 (2006). https://doi.org/10.1007/BF02690531
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02690531