Flomerics has introduced a step-by-step guide that integrates thermal and EMC design to help designers identify and resolve system-level electromagnetic compatibility (EMC) issues (www.floemc.com/stepbystep).
This unique guide recognizes that most new electronic products fail first-time EMC testing because manufacturers don’t usually evaluate system-level EMC performance prior to the prototype phase.
The first step in the new step-by-step process follows the development of a thermal budget, which is common practice in most teams involved in electronic design. The new approach departs from common practice in using analogous methods to simultaneously develop a full-spectrum shielding requirement. The shielding requirement is created by accruing EMC requirements that are set by regulatory bodies, the customer, and internal and external emissions susceptibility considerations.
At this point, the engineers responsible for thermal design usually lack detailed information, so they create a relatively rough thermal model of the entire system. The new approach departs from normal practice in using the thermal model to initiate an EMC simulation of the enclosure in order to identify resonances and determine which areas are sensitive from a shielding effectiveness standpoint.
The next stage of thermal management typically involves refining the simulation model. “Compact” models used in the simulation up to now may be replaced by more detailed and accurate models. The same refinements that are added to the thermal model make it possible to start looking at the effect of the physical layout on radiated emissions. A more detailed system-level model helps engineers quickly zero in on problem areas such as a heatsink, which acts as an antenna, and how the structure of the box contributes to emissions.
As the design process continues, mechanical engineers perform detailed thermal analysis of components that have been identified as potential problems. At this stage, engineers make adjustments to optimize the design from a thermal standpoint and, at the same time, determine the effect of design changes on EMC. For example, the effects of grounding heatsinks may be investigated and pc-board shields may be introduced to reduce radiation from high-speed components.
Combining thermal and system-level EMC design within an integrated analysis environment streamlines design collaboration between mechanical and EMC engineers, enabling early identification and remedy of system-level EMC compliance issues, and drastically reducing the risk of late-cycle compliance failure.
For more information, visit www.flomerics.com.
