A detailed study of variation in screen printed resistors on plastic

One of the major limitations of printed electronics is the large variation in properties of components produced using printing techniques. These variations can be caused by a number of factors, including (but not limited to) ink formulation, press instability, drying conditions, device design and environmental conditions. Understanding and minimising these variations is a major step in the direction of mass produced printed electronics. In this work we present a detailed analysis of variation in resistors printed on plastic films by flatbed screen printing. The study was performed as part of the production of multiplexed smart blister packs, which inherently required minimal variation in resistor properties. Firstly we present the results of an initial study into screen printed resistors. This study looked at the effect of resistor size, orientation and location upon the component resistance and variation. The second study was a detailed analysis of smart blister packages produced in a simulated production run of 119 devices. This study investigated the effects of alignment, resistor morphology and resistivity of components. These studies found that they key contributors to resistance variation are screen cleanliness, ink properties and device design. Strategies to mitigate these issues will be presented. Reduced component variation will enable many more potential applications for printed electronics.Peer reviewed: NoNRC publication: Ye