Novel Low Df Thermosetting Film and Photo Imageable Film

There are various demands for interlayer insulation film. One typical demand is a low dielectric loss (Df) for decreasing transmission loss as a low loss substrate. Another typical demand is low warpage, surface flatness and fine vias as an RDL substrate. We have developed two types of the novel interlayer insulation films, one was low Df thermosetting film and another was fine via type photo imageable film. Distinct feature of our novel low Df thermosetting film compared to the existing epoxy type low Df thermosetting film was its low Df (ca. 0.002@10GHz), which did not increase with temperatures and humidity, as was not the case with epoxy type low Df film. Distinct feature of our novel photo imageable film was its surface flatness and low warpage due to its lower CTE and curing temperature, compared to the existing poly imide (PI) based RDL material.