Toray Develops Positive Photosensitive Polyimide Curable at 170°C Low Temperature

Toray Japan announced on January 6, 2012 that Photoneece LT series, a photosensitive polyimide coating material that can be cured at a low temperature of 170°C, will be officially launched in April 2012. Positive photosensitive polyimide that can be cured at a low temperature of 170°C is still the "world's first case" (Toray) and can be used for semiconductor chip protective films (buffer layer films) using a low heat-resistant low-k film. And re-wiring layer insulation film. It is mainly aimed at a three-dimensional chip stack package that is applied to a chip on chip (CoC) and a through-silicon via (TSV).

Because polyimides are insoluble in solvents, they are usually induced by imidization on a wafer by applying a solvent containing a precursor and heating to form a solid film. In order to cause imidization, usually 250 is required. High temperatures around °C, but this time through the use of existing solvent-soluble closed-loop polyimide, without amination reaction can be cured at a low temperature of 170 °C. The heat-resistance of the film is generally lowered when the existing closed-loop polyimide is used. However, this time a self-developed cross-linking agent was introduced to improve the heat resistance, which solved this problem. In addition, the residual stress is also reduced to approximately 13 MPa or less which is half that of the conventional low temperature hardening type material.

The product is currently undergoing technical evaluation by 5 to 10 major semiconductor manufacturers at home and abroad. It is planned that after 3 to 4 years, it will become the main product of Toray positive photosensitive polyimide. Toray “Tops Global Shares” in Positive Photosensitive Polyimides (Dongli), but the company will strive to increase the global share of positive photosensitive polyimides by expanding sales of the LT series. "Upgraded to 50% before 2013-2014"