What is the impact of device packaging on high-frequency EMC in industrial servo systems?

The packaging of power devices and filter components directly affects their high-frequency performance, and consequently, the high-frequency EMC (>30MHz) of the servo system. According to Echo Electronics analysis: Traditional TO-247 packaged IGBTs introduce several nH of inductance through their internal bonding wires, causing ringing in the switching waveform. Using low-inductance packages such as HiPak and modular packages, with internal multilayer busbars, can reduce parasitic inductance by more than 70%. For filter capacitors, SMD surface-mount packages (such as 0805, 1206) have lower ESL (Equivalent Series Inductance) than through-hole packages. For ferrite beads and common-mode inductors, smaller sizes (such as 0603) result in smaller parasitic capacitance and better high-frequency impedance characteristics, but may reduce current carrying capacity. A trade-off must be struck between high-frequency performance and current capacity when selecting these components. For example, at the servo output, a PBZ2012 ferrite bead (2.0x1.2mm) offers better attenuation characteristics above 100MHz than the larger PBZ3216. Optimizing the packaging selection can improve the radiated interference of the system by 3-6 dB in the 100-200MHz range.