April 2, 2012 — Printed circuit board (PCB) technology company Rainbow Technology developed a touchscreen display manufacturing method that offers cost, speed, and environmental benefits over current methods, the company says.
The Rainbow Process Unit, originally developed for PCB production, produces fine line circuitry down to 5um: coating, imaging and developing a substrate in an automated process. Its proprietary etch wet resist is 100% solids- and solvent-free, and does not require pre-drying before imaging. UV LEDs and standard photo-tools create tracks and gaps of 20um and below. Power consumption on the unit averages 3kW.
The process can be done additively using an imaged seed layer to create electroless plated nickel or copper with a Rainbow imaged plating resist to create tracks. It can also be done subtractively using sputtered metal on plastic using a Rainbow imaged etch resist to create tracks.
Grid patterns of 5 x 300um pitch offer more conductivity than indium tin oxide (ITO) or conductive polymers, while maintaining good transparency. The closer tracks and gaps (down to 10um spacing) make touchscreens more responsive, enabling a more feature-rich user experience.
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For more information, visit www.rainbow-technology.com.