Laser Processing of Polyimide on Copper

While work using a laser for processing a polymer dielectric is currently being studied, the purpose of this thesis is to present an effective and economical approach using laboratory equipment that is most commonly used and available for the processing of materials including polymers and metals. The use of a laser allows for a more cost effective and flexible method for processing polyimide over other wet and dry processes.

This thesis represents the results of research on the laser processing of polyimide on copper. The research examines the effect of the laser processing parameters using a CO2 laser. The parameters examined include the pulse width, repetition rate, and number of pulses. The processed samples include freestanding Kapton with no adhesive layer, freestanding Kapton with an adhesive layer, and Kapton with adhesive layered on copper. The laser processing used a single laser shot with the parameters being varied over a series of shots fired. The effect of the parameters was observed over large and small ranges. The characteristics of processed freestanding samples were graphically presented along with captured images. The results demonstrate that the laser processing of polyimide is strongly dependent on the laser pulse width and that the optimum value from these experiments suggest the use of a pulse width of 60ms for using a CO2 laser. From these results, further considerations for the laser processing of polyimide on copper were given.