Design limitations of powertrain electronics — Automotive EMC challenges

Today´s safety features for modern vehicles require electronic controls for many functions such as engine command, fuel injection of diesel or gasoline, air bag deployment, and gas/brake pedal operation. Powertrain electronics such as the engine control module (ECM), power control module (PCM), diesel control module (DCM) or vehicle control module (VCM) support these functions when utilized. The electromagnetic compatibility (EMC) performance of these modules is challenged by small physical areas and volumes that are required by the vehicle manufacturer and the printed circuit board (PCB) design. The challenges are due to: 1) the large sizes of PCB components such as capacitors and inductors; 2) the increasing number of the integrated circuits such as IGPT, VSEP, the rapidly increasing number of in/output pins, and the complexity of connectors, causes even further reductions of available PCB area for EMC components; 3) ground via port techniques required for thermal management and caused by high voltages or currents of IGPT-elements. This paper reports on the design limitations for the issues described above. The conclusion of this is that the EMC performance of these modules is compromised when enough space is not allocated for EMC components. In addition, compact PCB elements with small sizes are not available for applying EMC design rules such as in-/output filtering, grounding or multi layer traces/planes decoupling. A study about the challenges of ground via ports required to achieve dynamic thermal performance and automotive EMC conclude the present investigations.