Thermal stability studies of a polyimide–polytetrafluoroethylene blend and its components

Abstract

Low‐dielectric constant (ϵr) polymers, such as polytetrafluoroethylene (PTFE), are an important component of advanced electronic products that transit data, since it is this physical property that largely determines a device's performance. For instance, the dielectric constant determines overall signal speed and proximity in that one circuit line can be placed to another, i.e., wiring density, while maintaining desired electrical characteristics. However, due to PTFE's inertness and intractability, significant challenges exist in the successful application of the polymer as an insulation material. One specific example is the lack of available methods to uniformly and controllably generate fine, high‐density features in the neat fluoropolymer. Recently, it was reported that excellent structuring characteristics of PTFE can be achieved by sensitizing the fluoropolymer to excimer laser radiation using small quantities of an aromatic polyimide. An important physical property of the sensitization agent, in addition to interacting strongly with the laser's emitted energy, is suitable thermal stability due to PTFE's high‐temperature processing requirements. Using multiple analysis techniques, the thermal decomposition behavior of PTFE, polyimide sensitizer, and resulting polymer blend have been evaluated. It was determined that the onset of decomposition for all systems is near or greater than 500°C. © 1994 John Wiley & Sons, Inc. Copyright © 1994 John Wiley & Sons, Inc.