PCB layout is a critical step prior to PCB processing. How can you design your files to effectively meet the production requirements of PCB manufacturing facilities?

1. **Solder Ring (Ring Ring)**: The solder ring of a PTH (plated-through hole) must be at least 8 mils larger than one side of the drilled hole, meaning the total diameter should be 16 mils larger than the drilled hole. Similarly, for Via holes, the solder ring must also be 8 mils larger than one side of the drilled hole, resulting in a diameter that is 16 mils greater than the drilled hole. In summary, whether it’s a through-hole PAD or Via, the inner diameter should exceed 12 mils, and the outer diameter should be greater than 28 mils. This is crucial!

2. **Line Width and Spacing**: The line width and spacing must be at least 4 mils, and the distance between holes should not be less than 8 mils.

3. **Etching Line Width**: The etching line width on the outer layer should be at least 10 mils. It’s important to note that this refers to etching, not silkscreen.

4. **Circuit Layer Design**: The circuit layer should incorporate a grid pattern (copper laid out in a grid format), with each rectangular grid space measuring at least 10×10 mils. This means that when copper is laid down, the line spacing should not be less than 10 mils, and the grid line width should be at least 8 mils. When applying a large area of copper, it is advisable to configure it into a mesh pattern for optimal material use.

This version retains the original meaning and technical details while improving clarity and flow.


First, it helps to prevent the PCB substrate and the adhesive of the copper foil from emitting volatile gases during dipping or heating. This gas can hinder heat dissipation, causing the copper foil to expand and potentially detach.

Secondly, it’s important to note that the thermal performance and high-frequency conductivity of a grid-like floor significantly surpass those of a solid floor. However, I believe the benefits of copper grids regarding heat dissipation cannot be generalized.

Consideration must be given to local heating that can lead to PCB deformation; in such cases, using grid copper can facilitate heat loss and maintain the integrity of the PCB. The advantage of this copper type is that it keeps the board surface temperature stable, albeit still within commercial or industrial standards, thereby minimizing damage to components. However, if bending results in virtual solder joints, it can directly lead to circuit failure.

The aim of comparison is to achieve minimal damage as the optimal solution. In terms of effective heat dissipation, solid copper is preferable. In practical applications, grid-like copper is rarely used in the middle layer; thus, the uneven stress from temperature changes is not as pronounced as in the surface layer, where solid copper provides superior heat dissipation.

5. The distance between the NPTH hole and copper should be greater than or equal to 20 mils.

6. For boards formed by milling, the distance between the copper and the forming line should be greater than or equal to 16 mils; therefore, during layout, the spacing between traces and the frame should also not be less than 16 mils. Similarly, when slotting, the distance to copper must be greater than or equal to 16 mils.

7. For die-punched boards, the distance between copper and the molding line should be greater than or equal to 20 mils. If the design might be mass-produced in the future, anticipate the need for mold opening to save costs during the design phase.

8. V-CUT (typically represented by lines on the Bottom Mask and Top Mask layers; it’s best to indicate where V-CUT is needed) should be designed according to the board thickness:

1. For a board thickness of 1.6mm, the distance between copper and the V-CUT line should be greater than or equal to 0.8mm (32 mils).

2. For a board thickness of 1.2mm, this distance should be greater than or equal to 0.7mm (28 mils).

3. For board thicknesses of 0.8mm to 1.0mm, the distance should be greater than or equal to 0.6mm (24 mils).

4. For boards less than 0.8mm thick, maintain a distance greater than or equal to 0.5mm (mil).

5. For gold finger boards, the distance between copper and the V-CUT line should be greater than or equal to 1.2mm (mil).

Note: Avoid setting such small spacings when designing for jigsaw puzzles; aim for the largest spacing possible.

The above guidelines outline the design rules for the outer circuit of PCB layouts.