Here is the abstract you requested from the imaps_2019 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.
|Low thermal resistance packaging for high power electronics|
|Keywords: Substrate, Low thermal resistance, packaging|
|Alumina and aluminum nitride substrates, typically 250 - 500 μm thick, are routinely used in micro- electronic packaging where large quantity of heat needs to be conducted away, such as in LED packaging, high power electronics and laser packaging. Heat management in high power electronics or LED’s is crucial for their lifespan. The ever-increasing need for higher power packages keeps challenging the packaging engineers to become more sophisticated in their packaging. With the availability of a 40 μm thick dense alumina from Corning with high thermal conductivity, the options available for packaging engineers has widened. This product has very high dielectric breakdown (~5kV at 40 μm thick), high thermal conductivity (>36 W/mK) and is rugged enough to be handled (with components attached) during packaging. These characteristics make dense alumina a cost effective alternative to incumbent materials such as alumina and aluminum nitride, to be used in high power LED/microelectronics packaging. As we show in this paper, a much thinner layer (~40 µm) of dense alumina in packaging can potentially deliver a performance on par with or better than a packaging unit with a thicker (500 µm) Alumina/ Aluminum Nitride. Complete understanding of heat flow is essential for designing optimized packing units. Numerical modeling serves as an efficient tool for analyzing thermal flow inside the packaging assembly. In this paper, two different applications are modeled using commercially available code from ANSYS®, to demonstrate the benefits of packaging with ultra-thin alumina for high power LED packaging and IGBT packaging. A geometry representative of typical LED packaging and IGBT packaging is constructed with Ansys Design Modeler platform and the allied meshing is done employing in-built Meshing tool in ANSYS Workbench®. A well posed steady state problem is solved by finding solution to the formulated energy equation. The solution to the energy equation helps in prediction of temperature distribution across various layers(components) in the packaging module. The predicted temperature field assists in computation of heat fluxes through different components (layers) in the packaging unit which can be employed to understand the heat flow inside the package. In addition to this, the numerical model also allows to estimate optimum thickness of different components in a packaging unit. In both applications considered in this paper, packaging with ultra- thin alumina is compared with typical existing packages. The IGBT package is also modelled similar to conventional packages, but with a small change to accommodate the handleability of ultra-thin alumina. Since a 40 μm alumina cannot be made into a doubly bonded copper substrate with 250 μm thick copper on both sides, modifications are made that does allows packaging for high power. As with LED, the package made with ribbon alumina does perform better than packages made with thick alumina and thick aluminum nitride.|
|Naga Shashidhar, Business Development Manager