Martin Riediker

Recent Advances In Photoimagable Polyimides

To date the use of photoimagable polyimide systems has been limited by lack of photo-speed, excessive volume contraction, and by shelf-life problems. These shortcomings have now been improved to the point where a practical, usable system has become available. Through the use of novel high quantum yield sensitizers, tailored to the g-line (436 nm) of the mercury spectrum, it is now possible to lower exposure times markedly and to reduce the amount of layer shrinkage that occurs in the final cure. Layers up to 70 microns and more of final cured polyimide can be photostructured at high resolution with an exposure energy of less than 1 J/cm2. The system presented is particularly useful for relatively thick layer applications as, for example, alpha particle protection, but can be used also for thin layer applications with accordingly shorter exposure times.