Polyimide-based photoresists

The different charaaeristics of polyimide-based photoresists are represented in Table 6.8 [57]. 

Polyimides are interesting thermally-stable polymers which could resist at high temperatures (more than 300 °C). These are used as insulation layers in microelectronics due to their good dielectric properties. Photoresists based on polyimides are very attractive because they allow direct patterning of the polymer. 

D.N. Khanna, W.H. Mueller, New high temperature stable positive photoresists based on hydroxy polyimides and polyamides containing the hexafiuoroisopropylidene (6-E) linking group, Polym. Eng. Sci. 29 (14) (1989) 954-959. 

Novel aqueous-developable photoresists have been formulated to process in dUute acidic media. A dry film based on electrophoretic depositable (ED) materials was shown to have excellent stability in strong alkaline solutions, potentially useful for etching polyimides or for full-build electroless copper plating. ... 

Fig. 11 Thin-film parylene-based microelectrode with embedded microfluidic channel. The pary-lene is structured in a reactive-ion etch. The photoresist serves as a sacrificial material, and it defines the channel shape. As with the polyimide fabrication process, the silicon substrate serves as a mechanical support during fabrication, and the parylene probe is removed in the last step. In this injection test, ink is passed through the microfluidic channel [67] - Reproduced by permission of The Royal Society of Chemistry...

The unique electronic stmcture of CNTs makes them ideal candidate materials for composite devices. SWNT/poly (3-octylthiophene) composite possesses properties suitable for use in photovoltaic cells.Composites with PMPV have been reported to be effective in organic light-emitting diodes as electron transport layers.Actuators based on SWNT/Nafion composites have potential applications as microswitches and artificial muscles. CNT/polyimide composites have been investigated for use as ultrafast optical switches. Such materials exhibited optical delay times less than 1 ps at a wavelength of 1.55 pm and showed great potential as all-optical switches. MWNTs dispersed in a photoresist epoxy can be applicable in the production of microelectromechanical systems such as electroplating molds, sensors, and aauators. ... 

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