Survey Report of Current Status of High Temperature Micro devices Packaging

Wide band-gap semiconductor materials such silicon carbide (SiC), gallium nitride (GaN), and diamond (C) based electronic devices may operate at temperatures above the high temperature limit of silicon technology. Among these wide band gap materials, single crystal SiC is the most mature material at this stage. SiC has such excellent physical and chemical material properties that SiC microsystems, including MEMS sensors/actuators and signal conditioning/computing electronics, have been demonstrated at temperatures in excess of 600C. Microsystems that can operate in harsh environments, such as high temperature (~600C), are necessary for many space and aeronautic applications. Sensors and electronics for space missions to the inner solar system or combustion/emission control sensors/ electronics located in an aeronautical engine environment are desirable. For example, the Propulsion Instrumentation Working Group (PIWG), a working group composed of government labs and engine manufactures, suggested that the minimum environmental temperature requirement for sensors operating in a warm section of turbine engine (fan area) is 500C (http://www.piwg.org/PDF/DynamicPressure.pdf). As a point of reference, SiC MEMS and semiconductor devices fabricated at NASA GRC have been demonstrated operable at temperatures as high as 600C. In order to test and commercialize high temperature microsystem technology, packaging technology is essential. Currently, most high temperature MEMS sensors/actuators and electronics have been tested only in laboratory environments for short term evaluation and demonstration. Most commercially available products have not been rated for long term high temperature operation. The major reason for this is that packaging technology for high temperature microsystems operability at and over 500C has not been completely evaluated/validated. Validating packaging technologies for SiC sensors/actuators and electronics is an immediate need for many NASA missions, and therefore, is one of the current tasks of the NASA Electronic Parts and Packaging Program. This article reports the survey results of the current status of high temperature micro-devices packaging.