Some Precautions In The PCB Production Process 2/2

Example 4, check the minimum distance between the edge of the PCB board or the non-tin plated through hole (NPTH) and the trace.

• The minimum distance between the edge of the PCB board and the trace is usually set to 1mm (0.5mm if necessary, not recommended) to prevent splitting of the trace when the PCB board is divided.

Set to 3mm. When using a machine to solder components to the PCB board, due to the limitations of the machine, it can avoid damaging the traces near the edge of the PCB board.

• The outline line of the pcb component (indicated by silkscreen) is usually kept at a distance of more than 1mm from the edge of the circuit board (except for components whose positions are specified in the design).

The pad of the component and the edge of the circuit board should be kept at least 1mm, usually 3mm to 5mm. In addition to preventing cracking, it also reduces the fatigue caused to the pad and prevents the pad from falling off the circuit board due to relative stress.

• The minimum distance between non-tinned holes (NPTH) and traces is determined by the use of non-tinned holes.

Normally, the distance between the component through hole and the trace is usually set to 1mm or more (if necessary, it can be set to 0.5mm, not recommended). But for the M3 screw hole, it is usually specified that wiring and components are prohibited within 10mm in diameter. Prevent metal screws from touching the traces and causing short circuits.

The above minimum setting is the design standard of the circuit board, not the setting value of CAM. All of the above inspections can be automatically carried out by setting CAM 3. When the inspection and correction work is completed, data for various processing devices can be generated.

Remark:

1. CAM: Computer Aided Manufacturing
2. The PCB design standards mentioned here are on top of the standards in the industry. Readers need to refer to the standard of the circuit board manufacturer in the PCB design to develop their own design standards.
3. The set value of CAM is based on the standard limit of the circuit board that the manufacturer can generate. Exceeding this standard limit will naturally not be able to produce a good circuit board. XPCB Limited is a powerful PCB manufacturer integrating pcb design, prototyping and production.