리버스 오프셋 인쇄의 전이특성에 따른 접착력과 응집력의 정량적 평가에 관한 연구

Abstract

Printed electronics are applied in the fabrication of electronic devices with various patterns printed using functional electronic ink and paste. In contrast to the conventional photolithography and vacuum-based vapor deposition method, the use of printed electronics involves a smaller number of steps in production, which reduces both time and cost. Conventional methods for quantifying printability rely on analyzing the rheological properties of ink, such as the viscosity, surface tension and contact angles. However, the printability cannot be directly-measured using those methods. Since the state of the ink sometimes changes during the printing process, thus, the new testing method is required. Contact transfer printing that use the surface energy difference between the mask (or cliché) and the substrate for the deposited or coated ink thin film. Nevertheless, it is not only difficult to measure the surface energy during the process, but also the ink shear cohesion has a effect on the ink separation. therefore, the new method of testing printability is required. For contact transfer prnting technology, ‘ink transfer’ of the ink happens due to interaction between ink-blanket adhesion and the ink shear cohesion. Therefore, the way to measure ink-blanket adhesion and the ink shear cohesion is proposed in this paper. In order to reach the goal, the device which was capable of simulating the contact transfer printing configuration was designed to measure the force acting on the ink. With using the proposed method, it is available to get the ink adhesion and cohesion in terms of force and energy by unit area. As a result of this, the adhesion and cohesion is analyzed as varying the film thickness, printing speed and the solid contents.