Push-pull process for contact defect-free patterning in reverse offset printing

Abstract

Reverse offset printing is one of the most promising printing techniques for printed electronics because it enables us to generate fine patterns with high fidelity. However, in the pattern-generation process, where some of the ink applied on a blanket is removed by a cliché upon contact, there may be contact-defect formations due to unwanted contact between the bottom regions of the cliché and the blanket. This may occur when the pattern size is wide or when the depth of the cliché is shallow. To solve this problem, we develop a modified printing protocol that adopts a 'negative' printing pressure condition called a 'push-pull' process. In this process, the blanket first comes into contact with the cliché by pushing a blanket roller, and the roller is then pulled back to prevent the blanket indentation into the grooves of the cliché. By incorporating the push-pull process in reverse offset printing, we demonstrate defect-free formations of 4.0 mm×5.0 mm large patterns using a shallow cliché with a depth of 2.6 μm, which is unattainable with the conventional push-only process. Further, we show that the adhesion between the ink-coated blanket and the cliché contributes to the maintenance of the contact through the printing process, even in the pull situation.

Reverse-offset for roll-to-roll high-resolution printing

“…Furthermore, the trailing edges have more edge raggedness which can be caused by torn in the nip opening. Kusaka et al [28,29] presented process improvements for contact defect-free patterning in roll-to-sheet RO printing to overcome these kind of anomalies. However, further studies are needed to exploit the method as a R2R process with a high overlay accuracy.…”

Printed Electronics Technologies for Additive Manufacturing of Hybrid Electronic Sensor Systems

“…A lot of scientific effort has been dedicated to optimizing the reverse offset printing process regarding the controlling of the ink transfer, [205] the positioning accuracy, [206] the used materials, [53] and the surface energies [207] resulting in an enhancement of the overall quality. Furthermore, the processing speed has been increased while reducing the related processing costs.…”

“…Reasons for that, are a too large pattern size or a shallow depth of the cliché. In an approach to address this issue, Kusaka et al [205] proposed a so-called "pushpull" process for the ink transfer. Instead of simply pushing the blanket roller onto the cliché, negative pressure is applied as well, which improves the ink transfer.…”

Development of a Strain Sensor Matrix on Mobilized Flexible Substrate for the Imaging of Wind Pressure Distribution

“…The industrialization of such large-area sensors requires an improved manufacturing process that can efficiently process the large areas. Thus, printing technology was developed to create functional layers in the atmosphere without the use of photoresists and the etching process [10][11][12].…”