New software and sensors are available for both the design and production phases to analyze and verify thermal management and performance. In addition, select electronic packages incorporate thermal and airflow analysis into their design, engineering and testing processes.

There are multiple steps that are essential to the analysis process. The first step, referred to as design phase thermal analysis, uses drawings and 3-D models for the projected system. Software, such as CFdesign® from Blue Ridge Numerics, Inc., can be used to create a detailed analysis of the thermal management picture — specifically how the cards, boards and chassis interact with cooling. The thermal analysis simulation lets you examine a range of component configurations to determine the best cooling solution. You can ascertain the ideal location for components, including cooling and exhaust fans, card cages, air filters and ventilation panels. Use of such simulation in the prototype stage has been shown to reduce the total project cost by an average of 65%.

Early stage analysis also aids in the selection of the physical composition of the chassis and components. The software can simulate the properties of different types of metals, be they a particular grade of steel, aluminum, copper, and so on, as well as metallic coatings.

As electronics continue to shrink in size, new technologies are needed to keep them cool. Currently, the leading technology for cooling chassis is a convection system that transfers heat with acutane water-cooled plates or cold plates. Thermal simulation analysis can simulate the effects of these options.

The results of the analysis help to build the unit, including where to plug the boards and cards into the system. During this production phase, verification can be performed on the chassis or card in thermal chambers. Sensors, such as Cambridge Accuesense sensors from DegreeC, analyze airflow and temperature. These sensors are ideal for testing all manner of chassis or card cooling configurations, including conduction, convection, and air- or liquid-cooled models.

Simulated thermal analysis can also be a useful tool in upgrading outdated systems. Often, customers want to increase the wattage in their existing components or materials, but use the same box. Thermal analysis technologies make it a lot easier to determine the feasibility of this request, especially if simulation technology was used in the original design process. Manufacturers can provide definitive answers quickly by simply plugging in new criteria into the existing stored simulation. From there, you can quickly determine that, for example, an additional 50 W of power will cause a 25° temperature increase — and this information can be provided within a matter of days.

Thermal analysis and airflow analysis have always been important steps in the design and production of electronic components, but now the technology is in place to take this analysis to new levels of accuracy and efficiency.

Carlo Gavazzi
www.carlogavazzi.com