With growing demand for more sophisticated and higher performance personal digital assistants, it is increasingly necessary to improve the processing capacity of a semiconductor. Accordingly, photosensitive positive coating materials that allows for high resolution by making the exposed part soluble are in great demand. Toray developed cold setting photosensitive positive polyimide that realized cold setting at 170 degrees centigrade with chemical resistance and heat resistance for the next-generation semiconductor protective film.
The new product is used for surface protection and warpage prevention. Its stress after hardening is 13 MPa, about half of the stress of the existing cold setting hardening. It hardly creates warpage even if it is applied to a thin wafer. Because of the low stress and the ability to harden at a low temperature, it is suitable for the Through-Silicon-Via (TSV) structure that accumulates multiple semiconductor chips vertically, and it contributes to improving the reliability of the next-generation semiconductor devices. It is being evaluated by semiconductor producers, and shipment is scheduled to start coming April. The company plans to increase its share of positive photosensitive polyimide in the world market to more than 50% by 2014.