Thin film passive elements on polyimide film

The General Electric Research and Development Center, Schenectady, NY, has teamed with Rensselaer Polytechnic Institute (RPI), Arizona State University (ASU) and Sheldahl, on the development of thin film deposition processes for the fabrication of passive elements on polyimide films. This program is targeted at processes for the fabrication of integral resistors, capacitors and inductors for mixed mode (combined analog/digital) applications operating up to 8 GHz. The overall goal is to develop processes for integration with flex circuit manufacturing and therefore provide government and industry with the capability to eliminate or reduce dependencies on discrete passive components in use today. Incorporation of passive components directly on polyimide flex circuitry will significantly reduce the overall size and weight of electronic assemblies, while improving the performance and reliability through complete metallurgical interconnect with the flex circuitry. Significant cost advantages are possible because most electronic module designs, such as portable applications, have passive to active component ratios in excess of 10:1. Elimination of a significant number of these passive components is possible with materials that have been developed under this program. This paper describes the processes that have been developed and discusses yield and performance data obtained from various test vehicles