Book excerpt: This is the first book to provide an in-depth presentation of photosensitive polyimides for electronic and photonic applications. The authors are leading specialists in this field from Japan, Europe and the U.S. From the Preface Aromatic polyimides were developed originally as thermostable flexible polymer films for space applications. Now polyimides have found widespread use in the manufacture of electronic devices and have been employed in increasingly diverse areas of electronics and information technology. In addition to their excellent thermal stability and high processability, a wide range of chemical and physical properties provided by molecular engineering makes polyimides highly versatile in the electronics and information industries. Lithography of polyimides is an inevitable process in using polyimides for microelectronic fields, and hence increasing research has been devoted to developing photosensitive polyimides, which make it unnecessary to use photoresists for patterning polyimides and diminishing markedly the number of steps in fabrication of various electronic devices. In addition, the development of technology of photosensitive polyimides is expected to play a great role in manufacturing photonic devices in the near future, when the design and control of hyper fine structures . . . including higher thermal stability and better processability would be essential.