How should the internal shielding partitions be set in an HMI (Human Machine Delivery System)?

Shielding partitions are installed inside HMI devices to isolate circuit modules with different functions and prevent mutual interference. Typical scenarios requiring partitions include: isolating switching power supply modules from digital/analog motherboards; isolating high-speed digital circuits from sensitive analog circuits; and isolating wireless modules from other circuits. The partitions should be made of highly conductive metal materials, such as galvanized steel, aluminum, or stainless steel. The partitions must have a good electrical connection to the main housing or internal grounding frame of the equipment, usually secured with screws or welded, with close connection points to ensure low impedance at high frequencies. The partition height should be sufficient, ideally reaching the underside of the top cover or another major shield.

For cables or connectors that need to pass through, treatment must be done at the partition openings: cables should be shielded, with their shielding layer connected to the partition via a feedthrough filter or shielding clip; signal lines can pass through by installing filter connectors on the partition. If only a single or a few low-frequency signal lines pass through, feedthrough capacitors or filter arrays can be installed on the partition. Setting up internal partitions increases cost and assembly complexity; therefore, they should be implemented only after layout planning and initial EMC assessment, targeting interference sources or sensitive objects where isolation is truly necessary. Echotronics can provide customized metal partitions and matching filter through-hole components to help achieve effective internal isolation.