After the wiring of the circuit board is completed, the planning rules of the circuit board shall be checked to ensure that the circuit board meets the planning requirements and all networks have been correctly connected. The inspection items commonly used in planning rule inspection are as follows:
Places where PCB wiring needs to be checked
1. Whether the spacing between lines, lines and component pads, lines and vias, component pads and vias, vias and vias is reasonable and meets the production requirements.
2. Whether the width of power line and ground wire is appropriate, whether the power supply and ground wire are tightly coupled, and whether there is room for widening the ground wire in the.
3. Whether the most preferred method is adopted for key signal lines, such as short length, protection line, input line and output line are significantly separated.
4. Whether analog circuit and digital circuit have their own independent ground wires.
5. Whether the graphics (such as icons and labels) added in the PCB will form a signal short circuit.
6. Whether to correct some unsatisfactory lines.
7. Whether there is a process line on the PCB, whether the resistance welding meets the requirements of the production process, whether the resistance welding scale is appropriate, and whether the character mark is pressed on the equipment pad.
8. Whether the outer frame edge of the power layer in the multilayer board is reduced. If the copper foil of the power layer is exposed, it is easy to form a short circuit.
The inspection results of planning rules can be divided into two types: one is report output to generate the inspection result report; The other is on line inspection, which is to inspect the electrical rules and wiring rules of the circuit board during the wiring process.