Laser sintering of Cu nanoparticles on PET polymer substrate for printed electronics at different wavelengths and process conditions

Abstract

This study explores the feasibility of different laser systems to sinter screen-printed lines from nonconductive copper nanoparticles (Cu NPs) on polyethylene terephthalate polymer film. These materials are commonly used in manufacturing functional printed electronics for large-area applications. Here, optical and thermal characterization of the materials is conducted to identify suitable laser sources and process conditions. Direct diode (808 nm), Nd:YAG (1064 nm and second harmonic of 532 nm), and ytterbium fiber (1070 nm) lasers are explored. Optimal parameters for sintering the Cu NPs are identified for each laser system, which targets low resistivity and high processing speed. Finally, the quality of the sintered tracks is quantified, and the laser sintering mechanisms observed under different wavelengths are analyzed. Practical considerations are discussed to improve the laser sintering process of Cu NPs.

Key words： laser sintering; copper nanoparticles; printed electronics

Acknowledgement

The corresponding author, Hongyu Zheng, would like to acknowledge the grant support of Shandong Taishan Scholar Scheme (Grant No. ts20190401).

References

1 Ko S H, Pan H, Grigoropoulos C P, All-inkjet-printed flexible electronics fabrication on a polymer substrate by low-temperature high-resolution selective laser sintering of metal nanoparticles. Nanotechnology, 2007, 18(34): 345202

2 Buffat P, Borel J P. Size effect on the melting temperature of gold particles. Physical Review A, 1976, 13(6): 2287–2298

3 Bieri N R, Chung J, Haferl S E, Microstructuring by printing and laser curing of nanoparticle solutions. Applied Physics Letters, 2003, 82(20): 3529–3531

4 Kim T Y, Hwang J Y, Moon S J.Laser curing of the silver/copper nanoparticle ink via optical property measurement and calculation.Japanese Journal of Applied Physics, 2010, 49(5S1): 05EA09(1-6)

5 Bieri N R, Chung J, Poulikakos D, An experimental investigation of microresistor laser printing with gold nanoparticle-laden inks. Applied Physics A, 2005, 80(7): 1485–1495

6 Kim M K, Kang H, Kang K, . Laser sintering of inkjet-printed silver nanoparticles on glass and PET substrates. In: Proceedings of the 10th IEEE International Conference on Nanotechnology. Seoul: IEEE, 2010

7 Chung J, Bieri N R, Ko S, In-tandem deposition and sintering of printed gold nanoparticle inks induced by continuous Gaussian laser irradiation. Applied Physics A, 2004, 79(4–6): 1259–1261

8 Ko S H, Pan H, Grigoropoulos C P, Air stable high resolution organic transistors by selective laser sintering of ink-jet printed metal nanoparticles. Applied Physics Letters, 2007, 90(14): 141103–141105

9 Bieri N R, Chung J, Poulikakos D, Manufacturing of nanoscale thickness gold lines by laser curing of a discretely deposited nanoparticle suspension. Superlattices and Microstructures, 2004, 35(3–6): 437–444

10 Choi T Y, Poulikakos D, Grigoropoulos C P. Fountain-pen-based laser microstructuring with gold nanoparticle inks. Applied Physics Letters, 2004, 85(1): 13–15

11 Chung J, Ko S, Bieri N R, Conductor microstructures by laser curing of printed gold nanoparticle ink. Applied Physics Letters, 2004, 84(5): 801–803

12 Ko S H, Chung J, Pan H, Fabrication of multilayer passive and active electric components on polymer using inkjet printing and low temperature laser processing. Sensors and Actuators A: Physical, 2007, 134(1): 161–168

13 Ko S H, Pan K, Hwang D J, . High resolution selective multilayer laser processing by nanosecond laser ablation of metal nanoparticle films. Journal of Applied Physics, 2007, 102: 093102

14 Alemohammad H, Aminfar O, Toyserkani E. Morphology and microstructure analysis of nano-silver thin films deposited by laser-assisted maskless microdeposition. Journal of Micromechanics and Microengineering, 2008, 18(11): 115015

15 Kumpulainen T, Pekkanen J. Utilization of 515 nm pulsed fiber laser for low temperature nanoparticle sintering. In: Proceedings of the 27th International Congress on Applications of Lasers & Electro-Optics. Temecula: Laser Institute of America, 2008

16 Son Y, Lim T W, Yeo J, . Fabrication of nano-scale conductors by selective femtosecond laser sintering of metal nanoparticles. In: Proceedings of the 10th IEEE International Conference on Nanotechnology. Seoul: IEEE, 2010

17 Kumpulainen T, Pekkanen J, Valkama J, Low temperature nanoparticle sintering with continuous wave and pulse lasers. Optics & Laser Technology, 2011, 43(3): 570–576

18 Lesyuk R, Jillek W, Bobitski Y, Low-energy pulsed laser treatment of silver nanoparticles for interconnects fabrication by ink-jet method. Microelectronic Engineering, 2011, 88(3): 318–321

19 Niizeki T, Maekawa K, Mita M, . Laser sintering of Ag nanopaste film and its application to bond-pad formation. In: Proceedings of the 58th Electronic Components and Technology Conference. Lake Buena Vista: IEEE, 2008, 1745–1750

20 Kim M K, Hwang J Y, Kang H, . Laser sintering of the printed silver ink. In: Proceedings of the 2009 IEEE International Symposium on Assembly and Manufacturing. Suwon: IEEE, 2009, 155–158

21 Laakso P, Ruotsalainen S, Halonen E, . Sintering of printed nanoparticle structures using laser treatment. In: Proceedings of the 28th International Congress on Applications of Lasers & Electro-Optics. Orlando, 2009

22 Aminuzzaman M, Watanabe A, Miyashita T. Direct writing of conductive silver micropatterns on flexible polyimide film by laser-induced pyrolysis of silver nanoparticle-dispersed film. Journal of Nanoparticle Research, 2010, 12(3): 931–938

23 Tsutsui Y, Yamasaki K, Maekawa K, . Size effect of Ag nanoparticles on laser sintering and wire bondability. In: Proceedings of the 60th Electronic Components and Technology Conference (ECTC 2010). Las Vegas: IEEE, 2010, 1870–1876

24 Yoon Y H, Yi S M, Yim J R, Microstructure and electrical properties of high power laser thermal annealing on inkjet-printed Ag films. Microelectronic Engineering, 2010, 87(11): 2230–2233

25 Kang B, Kno J, Yang M. High-resolution and high-conductive electrode fabrication on a low thermal resistance flexible substrate. Journal of Micromechanics and Microengineering, 2011, 21(7): 075017

26 Kang B, Ko S, Kim J, Microelectrode fabrication by laser direct curing of tiny nanoparticle self-generated from organometallic ink. Optics Express, 2011, 19(3): 2573–2579

27 Kim M G, Kanatzidis M G, Facchetti A, Low-temperature fabrication of high-performance metal oxide thin-film electronics via combustion processing. Nature Materials, 2011, 10(5): 382–388

28 Lee D G, Kim D K, Moon Y J, Effect of temperature on electrical conductance of inkjet-printed silver nanoparticle ink during continuous wave laser sintering. Thin Solid Films, 2013, 546: 443–447

29 Niittynen J, Abbel R, Mäntysalo M, Alternative sintering methods compared to conventional thermal sintering for inkjet printed silver nanoparticle ink. Thin Solid Films, 2014, 556: 452–459

30 Qin G, Watanabe A. Conductive network structure formed by laser sintering of silver nanoparticles. Journal of Nanoparticle Research, 2014, 16(11): 2684

31 Yung K C, Plura T S. Selective laser processing of ink-jet printed nano-scaled tin-clad copper particles. Applied Physics A, 2010, 101(2): 393–397

32 Joo M, Lee B, Jeong S, Comparative studies on thermal and laser sintering for highly conductive Cu films printable on plastic substrate. Thin Solid Films, 2012, 520(7): 2878–2883

33 Lee J, Lee B, Jeong S, Microstructure and electrical property of laser-sintered Cu complex ink. Applied Surface Science, 2014, 307: 42–45

34 Lee J, Lee B, Jeong S, Enhanced surface coverage and conductivity of Cu complex ink-coated films by laser sintering. Thin Solid Films, 2014, 564: 264–268

35 Yu J H, Kang K T, Hwang J Y, Rapid sintering of copper nano ink using a laser in air. International Journal of Precision Engineering and Manufacturing, 2014, 15(6): 1051–1054

36 Intrinsiq Materials. Screen print copper paste for PV metalisation. Available at Intrinsiq Materials website on September 15, 2019

37 Soltani A, Khorramdel Vahed B, Mardoukhi A, Laser sintering of copper nanoparticles on top of silicon substrates. Nanotechnology, 2016, 27(3): 035203

38 Kwon J, Cho H, Eom H, Low-temperature oxidation-free selective laser sintering of Cu nanoparticle paste on a polymer substrate for the flexible touch panel applications. ACS Applied Materials & Interfaces, 2016, 8(18): 11575–11582

39 Cheng C W, Chen J K. Femtosecond laser sintering of copper nanoparticles. Applied Physics A, 2016, 122(4): 289

40 Roy N K, Dibua O G, Jou W, A comprehensive study of the sintering of copper nanoparticles using femtosecond, nanosecond, and continuous wave lasers. Journal of Micro and Nano-Manufacturing, 2017, 6(1): 010903

41 Roy N K, Dibua O G, Foong C S, Preliminary results on the fabrication of interconnect structures using microscale selective laser sintering. In: Proceedings of ASME 2017 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems. San Francisco: ASME, 2017, IPACK2017-74173, V001T01A001

42 Roy N K, Jou W, Feng H, Laser sintering of copper nanoparticles: A simplified model for fluence estimation and validation. In: Proceedings of the 12th International Manufacturing Science and Engineering Conference. Los Angeles: ASME, 2017, MSEC2017-2975, V002T01A032

43 Perry R H. Perry’s Chemical Engineers’ Handbook. 7th ed. New York: McGraw-Hill, 1997

44 Shyjumon I, Gopinadhan M, Ivanova O, Structural deformation, melting point and lattice parameter studies of size selected silver clusters. European Physical Journal D, 2006, 37(3): 409–415

45 Son Y, Yeo J, Moon H, Nanoscale electronics: Digital fabrication by direct femtosecond laser processing of metal nanoparticles. Advanced Materials, 2011, 23(28): 3176–3181

46 Lawrence Yao Y, Chen H, Zhang W. Time scale effects in laser material removal: A review. International Journal of Advanced Manufacturing Technology, 2005, 26(5–6): 598–608

47 Hu M, Hartland G V. Heat dissipation for Au particles in aqueous solution: Relaxation time versus size. Journal of Physical Chemistry B, 2002, 106(28): 7029–7033

48 Kang J S, Kim H S, Ryu J, Inkjet printed electronics using copper nanoparticle ink. Journal of Materials Science Materials in Electronics, 2010, 21(11): 1213–1220

49 MacDonald W A. Engineered films for display technologies. Journal of Materials Chemistry, 2004, 14(1): 4–10

50 Bäuerle D. Laser Processing and Chemistry. Berlin: Springer, 2011, 739–781

51 Min H, Lee B, Jeong S, Laser-direct process of Cu nano-ink to coat highly conductive and adhesive metallization patterns on plastic substrate. Optics and Lasers in Engineering, 2016, 80: 12–16