DIY Fabrication of High Performance Multi-Layered Flexible PCBs

Abstract

We present a novel DIY fabrication workflow for prototyping highly flexible circuit boards using a laser cutter. As our circuits consist of Kapton and copper, they are highly conductive and thus support high-frequency signals, such as I2C. Key to our approach is a laser machine that supports both a CO2 laser as well as a fiber laser to precisely process respectively Kapton and copper. We also show how the laser cutter can cure soldering paste to realize VIAs (Vertical Interconnect Access) and solder components. In contrast, previous approaches for prototyping flexible PCBs through laser cutting only considered CO2 lasers which can not process metals. Therefore these approaches mainly used ink-based conductors that have a significantly higher electrical resistance than copper.