Collective laser-assisted bonding process for 3D TSV integration with NCP

  • Received : 2018.04.30
  • Accepted : 2018.10.08
  • Published : 2019.06.03


Laser-assisted bonding (LAB) is an advanced technology in which a homogenized laser beam is selectively applied to a chip. Previous researches have demonstrated the feasibility of using a single-tier LAB process for 3D through-silicon via (TSV) integration with nonconductive paste (NCP), where each TSV die is bonded one at a time. A collective LAB process, where several TSV dies can be stacked simultaneously, is developed to improve the productivity while maintaining the reliability of the solder joints. A single-tier LAB process for 3D TSV integration with NCP is introduced for two different values of laser power, namely 100 W and 150 W. For the 100 W case, a maximum of three dies can be collectively stacked, whereas for the 150 W case, a total of six tiers can be simultaneously bonded. For the 100 W case, the intermetallic compound microstructure is a typical Cu-Sn phase system, whereas for the 150 W case, it is asymmetrical owing to a thermogradient across the solder joint. The collective LAB process can be realized through proper design of the bonding parameters such as laser power, time, and number of stacked dies.


Supported by : Korea Institute of Energy Technology Evaluation and Planning


  1. P. Garrou, C. Bower, and P. Ramm, Handbook of 3d integration: Volume 1‐technology and applications of 3D integrated circuits, John Wiley & Sons, Hoboken, NJ, 2011, pp.13-24.
  2. T. Nonaka et al., High throughput thermal compression NCF bonding, in Electron. Compon. Technol. Conf. (ECTC), Orlando, FL, USA, May 2014, pp. 913-918.
  3. K. Matsumura et al., New non conductive film for high productivity process, in IEEE CPMT Symp. Japan (ICSJ), Kyoto, Japan, Nov. 2015, pp. 19-20.
  4. H. G. Lee et al., Effects of thermocompression bonding parameters on Cu Pillar/Sn‐Ag microbump solder joint morphology using nonconductive films, IEEE Trans. Compon. Packag. Manuf. Technol. 7 (2017), 450-455.
  5. A. Tong and F. Qin, Effects of the intermetallic compound microstructure on the tensile behavior of Sn3.0Ag0.5Cu/Cu solder joint under various strain rates, Microelectron. Reliab. 54 (2014), 932-938.
  6. N. Asahi et al., High productivity thermal compression bonding for 3D‐IC, in IEEE 3D Syst. Integr. Conf. (3DIC), Sendai, Japan, 2015, pp. TS7.3:1-5.
  7. N. Asahi, 3D‐IC thermo‐compression collective bonding process using high temperature stage, in IEEE Int. Conf. in Electron. Packag. (ICEP), Yamagata, Japan, Apr. 2017, pp. 536-529.
  8. A. B. Lim et al., High throughput thermo‐compression bonding with pre‐applied underfill for 3D memory applications, in IEEE Electron. Packag. Technol. Conf. (EPTC), Singapore, 2016, pp. 427-434.
  9. Y. G. Jung et al., Development of next generation flip chip interconnection technology using homogenized laser‐assisted bonding, in IEEE Electron. Comp. Technol. Conf. (ECTC), Las Vegas, NV, USA, 2016, pp. 88-94.
  10. C. H. Kim et al., Development of extremely thin profile flip chip CSP using laser assisted bonding technology, in IEEE CPMT Symp. Japan (ICSJ), Kyoto, Japan, 2017, pp. 45-49.
  11. K.‐S. Choi et al., Development of stacking process for 3D TSV (through silicon via) structure using laser, in Int. Symp. Microelectron. Assembly Packaging soc. (IMAPS), Raleigh, NC, USA, Oct. 9 -12, 2017, pp. 67-71
  12. Y.‐S. Eom et al., Characterization of fluxing and hybrid underfills with micro‐encapsulated catalyst for long pot life, ETRI J. 36 (2014), no. 3, 343-351.
  13. C. Tams and C. Enjalbert. The use of UV/Vis/NIR spectroscopy in the development of photovoltaic cells, PerkinElmer Resources, Feb. 18, 2018, available at
  14. F. Padera. Measuring absorptance (k) and refractive index (n) of thin films with the PerkinElmer LAMBDA 950/1050 high performance UV/Vis/NIR spectrometers, Feb. 18, 2018, available at
  15. J. Piprek, Heat generation and dissipation, Semiconductor optoelectronic devices: Introduction to physics and simulation, Elsevier, San Diego, CA, 2013, pp. 145-147.
  16. J. Piprek, Dielectric function, Semiconductor optoelectronic devices: Introduction to physics and simulation, Elsevier, San Diego, CA, 2013, pp. 87-91.
  17. W. Frei, Modeling laser‐material interactions with the Beer‐Lambert Law, COMSOL BLOG, 2016, Dec. 21, 2017, available at
  18. M. A. Green and M. J. Keevers, Optical properties of intrinsic silicon at 300 K, Prog. Photovoltaics 3 (1995), no. 3, 189-192.
  19. K. Rajkanan, R. Singh, and J. Shewchun, Absorption coefficient of silicon for solar cell calculations, Solid‐State Electron. 22 (1979), no. 9, 793-795.
  20. W. A. Braganca, Properties of NCP with different silica filler for 3D TSV multi‐stack integration, Master Dissertation, University of Science and Technology, 2017.
  21. N. Zhao et al., Growth kinetics of Cu6Sn5 intermetallic compound at liquid‐solid interfaces in Cu/Sn/Cu interconnects under temperature gradient, Sci. Rep. 5 (2015), 1-5.