Will the EMC performance of an edge computing box decrease after high-temperature aging?

After high-temperature aging, the drift of filter component parameters in edge computing boxes may lead to a decline in EMC performance. For example, the Curie temperature of the common-mode inductor CML4532A-101T core is >125℃, but after long-term aging at 85℃ for 1000 hours, the inductance may decrease by 10%. The impedance temperature coefficient of the PBZ1608E600Z0T ferrite bead is about 2000ppm/℃, and the impedance decreases by 12% at 85℃. The capacitance of the MLCC X7R capacitor decreases by more than 10% at 85℃.

Solution 1: Use automotive-grade components such as CML4532A-101T with an operating temperature of -55℃ to 150℃ and an inductance temperature drift of <5%.

Solution 2: Derating design with margin. For example, if a 60Ω ferrite bead is originally required, select PBZ1608E800Z0T 80Ω. Even after high temperature, it will still have a 60Ω capacity.

Solution 3: Measure the radiated emissions of 5 units before and after aging, establish a data model, and optimize the selection based on actual measurements. After 1000 hours of high-temperature aging, the EMC margin of the edge box is still greater than 3dB.