Laser Direct Writing of Conductive Silver Micropatterns on Transparent Flexible Double-Decker-Shaped Polysilsesquioxane Film Using Silver Nanoparticle Ink

Abstract

This paper describes fabrication of conductive, highly adhesive silver (Ag) micropatterns on transparent flexible double-decker-shaped polysilsesquioxane (DDPSQ) film by a laser direct writing technique using a precursor film prepared from liquid-dispersed Ag nanoparticles. The laser-written Ag micropatterns have been characterized by optical microscopy, field-emission scanning electron microscopy, surface profilometry, and resistivity measurements. The line width of the Ag micropatterns can be flexibly controlled by changing the objective lens magnification and laser spot size. Using a 9100 objective lens and laser energy density of 170.50 kW/cm 2 , Ag micropatterns with line width of about 4 lm have been achieved. The Ag micropatterns show excellent adherence to the DDPSQ surface as evaluated by Scotch-tape test. The resistivity of the Ag micropatterns has been determined to be 4.1 9 10 À6 X cm using the two-point probe method, being almost comparable to that of bulk Ag (1.6 9 10 À6 X cm). Thus, high-quality, narrow, homogeneous Ag microlines with high conductivity and adhesion can be produced under optimized laser scanning conditions.

Laser Direct Writing and Selective Metallization of Metallic Circuits for Integrated Wireless Devices

“…Laser direct writing is a noncontact, fast, single-step fabrication technique with no need for masks, postprocessing, and a complex clean room, and compatible with current electronic product lines for commercial use; thus, it has potential to be employed in the surface-selective activation or catalyst distribution, − fabrication of materials with specific patterns, − and even preparation of self-powered integrated devices . Recently, we have demonstrated the fabrication of high-performance flexible carbon micro-supercapacitors (MSCs) by laser-induced carbonization from polyimide (PI) films in air or Ar, a flexible photo-rechargeable carbon/TiO 2 composite MSC on a PI film prepared by combining the laser direct writing technique and electrophoretic deposition, and a self-powered integrated photodetective system on a PI film. ,, Transparent electrodes with grid metal lines can also be fabricated by laser direct writing on the substrate coated with metal nanoparticle inks through laser-induced sintering. − Recently, laser direct writing combining with selective metallization has been reported to prepare Ni electrodes for high-performance MSCs on a textile using a laser-scribed masking route, but the conductivity may not be high enough for practical application in electronic devices . Therefore, new strategies for preparation of high-conductive metallic circuits as well as the demonstration of integrated devices for energy and data exchange on a flexible substrate are still required to promote the development for practical use.…”

Laser-assisted fabrication of single-layer flexible touch sensor

“…Although alternative printing methods such as inkjet and roll printings can be used, the minimum resolution that they can provide is larger than that required for such a touch sensor 16 20 21 . Since the laser sintering process using metal nanoparticles (NPs) fabricates fine metal tracks of less than 10 μm, this method have been also applied to realize the metal mesh-based touch sensor fabrication in spite of a resistive type of touch sensor 22 23 . However, this approach is not cost-effective to be applied to practical production.…”

“…1(b,c) . This fabrication method has great merits, such as the huge reduction of material and laser cost compared to conventional laser sintering methods 22 23 via easy in-process generation of ultrafine nanoparticles of 2~3 nm from a low-cost solid-free organometallic solution, process optimized to a NIR laser, one-step production of high-fidelity microstructure, and green manufacturing by low-temperature processing in air. Thus, this study can provide a practical solution to the existing problems characterizing transparent conductive materials and their related applications.…”