Transient Thermal Modeling of Electronic Devices Using ElectroFlo

Gallium nitride offers spectacular performance advantages over silicon when applied to power switching – high voltage breakdown, low on‐resistance and unprecedentedly high current densities. GaN Systems in particular has developed a range of devices that fully exploit these attributes. In implementing these devices very considerable thermal and packaging challenges had to be overcome, and innovative solutions devised. This paper describes techniques developed in conjunction with ElectroFlo software for the modeling of thermal transients.

The transient thermal characteristics of a semiconductor device are very important in the prediction of device thermal behavior in different conditions such as switching applications. Knowing the thermal impact of pulse duration for different duty cycles helps to apply the device more efficiently. That is why transient thermal impedance curves appear in many MOSFET data sheets, application notes, and in the literature (see references).

Transient heat transfer is a very complicated process and it is not always easy to obtain results experimentally. Due to the extremely fast response times it is difficult to capture the transient reaction, while the very small device size makes temperature measurement difficult without affecting the behavior. For these reasons thermal simulations assume great importance. The purpose of this paper is to show how this can be done using the thermal analysis software, ElectroFlo.

Read the full white paper

Dr. Ben Zandi is presenting an Aerospace Electronics webinar through the Altair Partner program on Thursday October 4th at 10am

Here is the link to the webinar on the Altair site. http://hyperworksalliance.com/EventDetail.aspx?event_id=2906&event_culture=Global&region=Global&date_location_id=2387

Title: Advances in Modeling and Simulation of
Complex Thermal Management Systems

 

Abstract:

Speed and accuracy are critically important in the
modeling and simulation of thermal systems and components. Today’s software
packages either offer approximate modeling using one-dimensional simplistic
flow/thermal network solvers for quick prediction of flow and thermal fields,
or detailed modeling using complex and sophisticated three-dimensional
heat transfer and computational fluid dynamics.  The first approach
provides the simulation speed, sacrificing accuracy and can lead to oversimplification,
while the second approach offers accuracy at the cost of speed.
Therefore, the analyst is often forced to make a choice between the two
approaches, or link the two methods.  This coupling procedure involves a
very tedious and time-consuming task of interfacing between the two packages
made more difficult without access to the source code.

 

This presentation discusses the advantages and
shortcomings of each methodology and offers a hybrid approach to bridge the gap
between “speed” and “accuracy”.  A variable-fidelity thermal modeling and
simulation methodology is introduced offering a variety of approaches for
modeling complex systems. These include: embedded 2D thermal/electrical planes
ideal for trace modeling, coupled 1D thermal/electrical network for component
definition, and embedded 1D flow-network for modeling of liquid cooling
channels.  This approach demonstrated through thermal/electrical/CFD
analysis of a liquid-cooled complex Electronic system.

 

ITherm Conference Paper

Hamish Lewis, one of TES’s Engineering Managers, is presenting a paper entitled ”VARIABLE FIDELITY METHODOLOGY FOR THERMAL BATTERY MODELLING” at the ITherm international conference in San Diego this week. This paper discusses the use of our new Software ADFlo for the thermal analysis of Battery systems in automotive applications. Satish Ketkar, a Wayne State Professor and consultant at LG Chem. a battery system manufacturer, is a co-author on the paper.

TES chairman gave keynote presentation at the SAE World Congress

TES chairman, Dr. Ben Zandi, recently gave a keynote presentation at the SAE World Congress on “Advances in Modeling and Simulation of Vehicle Thermal Management Systems”. Below is the description of the presentiation:

Speed and accuracy are of paramount importance in the modeling and simulation of vehicle systems and components. Today’s commercially available thermal/flow analysis software packages either offer speed or sacrifice speed for accuracy: 1) approximate modeling using one-dimensional (1D) simplistic network solvers (flow and thermal) for quick prediction of flow and thermal fields, or 2) detailed modeling using complex and sophisticated three-dimensional (3D) heat transfer and computational fluid dynamics. The first approach provides the simulation speed, sacrificing accuracy and can possibly lead to oversimplification, while the second approach offers accuracy at the cost of speed. Therefore, the analyst is often forced to make a choice between the two approaches, or find a way to link or couple the two methods. The linking between one-dimensional and three-dimensional models using separate software packages has been attempted and accomplished for a number of years with some frustration. This coupling procedure involves a very tedious and time-consuming task of interfacing between the two packages made more difficult by the lack of access to the source code. Furthermore, there may be issues relating to overall convergence, as well as the convergence of each solver, which can lead to compromised accuracy. For a truly coupled approach, modifications to the source code of the solvers would be required if the analysts had access to it.

This presentation discusses the advantages and shortcomings of each methodology and offers a hybrid approach to bridge the gap between “speed” and “accuracy”. A complete thermal modeling and simulation methodology is introduced offering a variety of approaches for modeling complex systems and components. This avoids any of the unnecessary “overhead” associated with a single modeling approach type. As an example, by allowing the combination of a full three-dimensional analysis in the radiator and the use of a network-based approach for pipes and pumps, the analyst can study the effects of orientation, fouling and related environmental conditions within the radiator and its effect on the complete system. The ability to combine these modeling approaches within a single system model allows one to employ the right tool for the job. This greatly reduces the model development / analysis time allowing for the timely generation of results from which informed design decisions can be inferred. This modeling approach is demonstrated though 1D/3D examples analyzed using the ADFlo software package.