Here is the abstract you requested from the Thermal_2010 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Thermal Analysis and Testing of a Radio Frequency Pin Diode Switch for Avionics Applications|
|Keywords: analysis, correlation, thermal|
|A pin switch diode assembly has been designed by Rockwell Collins, Inc. (RCI) for deployment on government airborne antenna electronics. A prototype of this assembly was fabricated and its thermal behavior was evaluated through both finite element modeling and lab testing. This presentation describes the thermal finite element analysis and the use of thermal test results for calibrating the model. Analysis and test support to the hardware design team necessarily required quick turnaround response to provide timely design feedback during the assembly design process. The presentation will discuss how features of the assembly were determined to have little impact to thermal behavior and were therefore not included in the finite element model. The resulting thermal model produced die-level temperature predictions that correlated to within 3°C standard error of the measured data. The pin diode switch is an assembly that includes two circuit layer disc-shaped ceramic substrates and up to four surface mount pin diode die. This hybrid microcircuit has a relatively high power density that can provide significant thermal challenges in terms of both thermal expansion mismatch between the assembly's various materials and maintaining die temperatures below the manufacturer's maximum limitations. The use of a RCI-developed diamond-glass composite material  as an encapsulant in the device addressed both of these issues.. Previous work has already validated the encapsulant's ability to alleviate the thermal expansion problem; the current work examines its effect at spreading the heat to reduce hot spots within the package. 1. Nate Lower and Ross Wilcoxon, “Alkali Silicate Glass Based Thermal Coatings”, SEMI-THERM 2010, February 2010, San Jose, CA|
|Robert Meikle, Principal Mechanical Engineer
Rockwell Collins, Inc.
Cedar Rapids, I