SYNTHESIS AND CHARACTERIZATION OF A LOW STRESS PHOTOSENSITIVE POLYIMIDE

Use of polyimides with thermal coefficients of expansion comparable to that of the underlying substrate is critical to achieving low stress in microelectronic packaging applications. Photosensitive polyimides are finding increased use because of their significant reduction in device processing steps. A negative working photosensitive polyimide, based on the BPDA/PPD backbone, has been synthesized that incorporates these key features. The polyimide exhibits excellent photosensitivity and lithographic behavior, while retaining many thermal and physical properties of the polymer framework.