Roll-to-roll processing of film substrates for hybrid integrated flexible electronics

Abstract

Roll-to-roll (R2R) processing on film substrates has been demonstrated to have the potential for achieving high throughput manufacturing of organic electronic systems at low cost. However, the ever-growing mobile devices market accompanied by the developments in information and communication technologies require high performance systems at very low power operation, sometimes on larger substrates having sizes in the range of a few metres. Organic electronics often fall short of fulfilling the required computing performance and power requirements of most of the common use cases. Hybrid integration of inorganic monocrystalline silicon chips on polymer films is a means to fulfil the aforementioned requirements. In this context, it is opportune to report our recent activities on R2R processing of plastic films for hybrid integration of flexible electronics. Hybrid integration can be performed with conventional, rigid surface mount devices as well as flexible, ultrathin bare silicon chips. The first section of the paper is dedicated to a brief overview of R2R manufacturing of electronic devices with an example of production of radio frequency identification tags as well as to a discussion emphasising the targets for hybrid integration. Then, detailed descriptions about our processes for R2R manufacturing of metal wiring lines on films and hybrid integration are included. Three-dimensional integration of films and a temperature sensor label manufactured using hybrid integration process are also elaborated on. Furthermore, key results from fatigue reliability assessment of R2R metallised wiring lines are reported. Finally, some of the challenges in transferring the R2R processes for hybrid integration on film substrates from research labs to industrial manufacturing are highlighted.

Fabrication Methods for Microfluidic Devices: An Overview

“…Palavesam et al [ 224 ] have described integration of multiple processes within R2R equipment, including sputtering or metal film on web substrate; web to web lamination e.g., lamination of dry film photoresist; lithographic patterning; electroplating of copper for fabricating wiring lines; screen printing of materials; chip bonding; and laser cutting. A temperature sensor label ( Figure 7 A) was demonstrated using a hybrid integration process which comprises screen printing, assembly of surface mount devices (SMD), and 3D integration of foils through lamination of pressure sensitive adhesive (PSA) tape for low-temperature gluing and use of laser to create via holes [ 224 ]. Figure 7 B shows impedimetric point-of-care diagnostic cartridge for biomarker detection, which comprises an electrode layer using PEN substrate and a hot embossed fluidic layer and with both of these layers being joined using PSA tape that is laser-structured to open selected areas of the electrode layer [ 222 ].…”

Photonic curing of solution-deposited ZrO2 dielectric on PEN: a path towards high-throughput processing of oxide electronics

“…Beyond cases where mechanical flexibility is necessary for the device application, flexible substrates enable high-throughput roll-to-roll manufacturing processes, which bring the advantage of low capital cost and the economy of scale 5 . For example, roll-to-roll manufacturing has enabled the proliferation of low-cost radio frequency identification tags over the last 2 decades 6 and is a major goal in the production of organic electronics 7 and perovskite solar cells (PSC) 8,9 When sheet-to-sheet PSC throughput is increased from 0.5 to 2.5 m 2 /min, manufacturing costs decrease by~35% 10 . A web speed of 30 m/min would allow for production of 3 GW/year of solar panels from a single roll-to-roll system (www.enmatcorp.…”

Recent Progress in Inkjet‐Printed Thin‐Film Transistors

“…These achievements have facilitated large‐production throughput, and enabled low‐cost production per unit area. Printed electronics can leverage the high‐throughput additive manufacturing process demonstrated at low‐cost in graphic arts applications . Here, the additive nature allows fast processing and imparts cost savings by depositing the materials where they ultimately need to be located.…”

“…Because of the relatively poor resolution and complex processing in screen and flexography printing, respectively, gravure and inkjet printing among the different printing techniques have been widely used as suitable processing methods for the realization of thin‐film devices . Specifically, gravure printing allows high‐resolution, high‐throughput, and good pattern fidelity for fabrication . However, the inherent contact nature of gravure printing and the use of high‐viscosity ink with binders cause contamination/residue issues and degradation of the printing materials, respectively.…”