A kind of negative photoresist, composed of photosensitive polyimides and N methyl 2 pyrrolidone was formulated. The curing mechanism and the relationship of the properties and structure of PSPIs were studied. The results of TGA show that the PSPIs have excellent heat resistance. Based on our research, the pattern with line width as low as 2.5 μm was gained with the conventional UV photolithography under the optimum parameters.
