How to optimize the wiring of the I/O module isolation barrier?

Optimizing the routing of the isolation barrier area on the I/O module PCB is crucial for maintaining high isolation and preventing flashover. First, slots must be cut beneath the isolation barrier, effectively removing all inner layer ground and power planes to create complete air isolation. The slot width must meet safety regulations regarding creepage distances and clearances. All signal lines crossing the isolation barrier must pass through isolation devices, such as optocouplers and isolation chips, which should be bridging the slot. During routing, traces on both sides of the isolation barrier must not run parallel to or cross the slot to prevent arcing or capacitive coupling. Isolated DC-DC modules powering the isolation devices should also be bridging the slot, with their primary and secondary pins positioned on opposite sides. On both sides of the isolation barrier, there should be independent grounding copper traces for connecting the input/output ground pins of the isolation devices and filter capacitors. These copper traces should not be extensively connected to the main ground plane; instead, they should be connected at a single point or be completely independent. After layout, a withstand voltage test must be performed to verify whether the isolation barrier breaks down or experiences excessive leakage current under high voltage. 3D modeling software can be used to check if the creepage distance meets the requirements.