New Growth Point of Polyimide Film Market

The growth of electric vehicle market will bring the corresponding growth of polyimide film market.

Surface passivation process of high voltage power devices is an important process link in the manufacturing process of power devices. It has an important influence on the electrical performance and reliability of the device. Surface passivation technology is to isolate the power device from the surrounding atmosphere by high-voltage passivation materials, to prevent the chip surface contamination from affecting the electrical properties of the device (such as surface conductance and surface state), to control and stabilize the characteristics of the semiconductor surface, to protect the internal interconnection of the device, to prevent the device from mechanical and chemical damage, and to improve the reliability level of the power device.

Polyimide is an important material for passivation process of high voltage IGBT chip surface. Polyimide has high temperature resistance, good insulation performance, simple process, stable chemical properties, good step coverage and good thermal matching with aluminum. It is widely used in passivation of the outermost surface of high voltage chips, but its ability to resist moisture and ion contamination is not strong enough, so it needs to be used with inorganic passivation structure. According to the sensitivity of different structures to light, polyimide can be divided into non-photosensitive polyimide and photosensitive polyimide. Passivation process of polyimide with two different structures is different. Passivation process with non-photosensitive polyimide is generally as follows: pretreatment-coating-photoresist coating-lithography-etching-stripping-curing. The lithography process of non-photosensitive polyimide is very complex, which also increases the difficulty and reliability of the whole passivation process, and at the same time increases the manufacturing cost.