Investigation of DLP Projector as an Energy Light Source to Cure Silver Conductive Ink

Abstract

Conductive ink has been widely used in many application of electronic parts. It normally comes in liquid form and will need to be cured usually by conventional oven or laser irradiation after it is drawn to expose its metallic contents. But, these curing processes suffer from numerous problems consist of laser is a costly process and a warping defect when cured using conventional oven. Thus, alternative process is prominent and DLP projector has been seen capable of polymerised photopolymer materials. By making use of its potential associated with a proper control of the light intensity, exposure time and distance, it could provides sufficent heat to cure conductive ink. This study investigates the curing process of silver conductive ink on polymer substrate using DLP projector light with a variation of curing time and distance. Electrical resistance, hardness and adhesion level of cured sample were measured to determine its functionality. The conductive ink is deposited on the substrate using a doctor blade method and Microsoft Powerpoint slide is used to shape the light image produced by the projector. It was found that the conductivity and curing level of the sample cured were higher at the distance which getting the sharpest light image. The performances of the samples were also greater as the curing time increased. DLP projector is able to cure the conductive track efficiently with shorter curing time apart from the cheap preparation and setup cost.