Low Temperature Processable Ultra-Low Dielectric Porous Polyimide for High Frequency Applications

Ultra-low dielectric porous polymer coatings reduce electrical losses of high speed and high frequency circuitries. In this investigation, a room temperature process to produce ultra-low dielectric polyimide films was developed. The films have low elastic properties which reduce thermal stresses and package warpage. The dielectric properties of the porous polyimide were characterized at 100 KHz as well as between 8.2 and 18 GHz. Results showed that the dielectric constant reached as low as 1.67 in high porosity films. The results indicate that the high frequency dielectric properties are stable and the films are suited for use in wide band applications. On the basis of the improved properties, the usages of low temperature processable ultra-low-k polyimide in advanced applications are discussed.