PCB Design Issues
Drilling Hole
- Problem:
Irregular hole ring design - Risk:
May confuse hole attributes - Recommendation:
Hole ring should be a hollow ring
- Problem:
Holes without wire connections - Risk:
May lead to incorrect hole attributes - Recommendation:
Clearly define hole attributes in the source files
- Problem:
Slot holes and circular holes overlap - Risk:
Unable to determine the required hole type - Recommendation:
If both need to be drilled, design them in the drilling layer; or remove one of the holes
- Problem:
Slot holes designed in the sub-hole layer - Risk:
May result in the loss of slot holes - Recommendation:
Design slot holes in the drilling layer
- Problem:
Circular holes designed in the drilling layer - Risk:
May result in the loss of slot holes - Recommendation:
Design circular holes in the sub-hole layer
- Problem:
Spacing between plug holes is too small - Risk:
May lead to solder pad deformation, reduced soldering area, and cold soldering - Recommendation:
Reduce finished hole diameter or increase hole spacing
- Problem:
Eight-shaped hole design - Risk:
May cause burrs on hole walls and severe copper peeling - Recommendation:
Increase spacing of figure-eight holes or change them to slot holes
- Problem:
Finish size of vias exceeds 0.2mm - Risk:
May affect plugging effectiveness - Recommendation:
Avoid designing multiple hole sizes for vias; annular ring difference should not exceed 0.2mm
- Problem:
Distance of vias from board edge is too close - Risk:
May cause copper leakage at board edges - Recommendation:
Distance between vias and board edge should be greater than 10 mil
- Problem:
Drilling holes on ICs and small solder pads - Risk:
Reduces soldering area, leads to pad fractures, and may cause soldering issues - Recommendation:
Try to avoid drilling vias near small solder pads
Routing
- Problem:
Disconnected traces prone to short circuits - Risk:
High risk of short circuits during production - Recommendation:
Avoid designing disconnected traces
- Problem:
Bare copper traces designed at board edges - Risk:
May be mistaken for milling traces - Recommendation:
Design bare copper traces only on solder mask layers
- Problem:
Mixing PCBs with significantly different copper residue rates - Risk:
Leads to uneven distribution of copper on low-residue-rate areas - Recommendation:
Produce PCBs with large differences in copper residue rates separately
- Problem:
No differentiation between copper pour and various traces (such as impedance traces) - Risk:
Increases engineering production time and costs - Recommendation:
Differentiate between copper pours and trace sizes
- Problem:
Existence of cut-off traces - Risk:
Factories cannot determine whether such cut-off traces are normal - Recommendation:
Ensure regularity in design documentation
- Problem:
Copper laying on the edge of the board does not avoid the position of the milling cutter - Risk:
Factories may assume such copper width as ineffective - Recommendation:
When designing copper pour, avoid milling tool paths
Solder Mask
- Problem:
Gerber data conflicts with via covering method - Risk:
May lead to incorrect via covering - Recommendation:
Ensure consistency between via covering data and drilling method
- Problem:
Lines with pads lacking solder mask openings - Risk:
May result in solder mask covering pads - Recommendation:
Design solder mask openings for pads
- Problem:
Excessive solder mask design for tin lines - Risk:
Excessive tin lines may lead to exposed copper - Recommendation:
Reduce the length of tin lines
Screen Printing
- Problem:
Characters overlapping with solder pads - Risk:
May cause loss of characters - Recommendation:
Avoid designing characters on solder pads
- Problem:
Characters designed too small - Risk:
Small characters are difficult to recognize - Recommendation:
Increase the size of characters appropriately
- Problem:
Avoid designing overlapping characters - Risk:
Results in unclear characters - Recommendation:
During design, avoid overlapping characters
- Problem:
Polarity symbols hidden - Risk:
May lead to loss of polarity symbols - Recommendation:
Ensure important characters have a safe distance from solder pads
Board Edge
- Problem:
Component positions are locked - Risk:
Prevents movement and selection operations - Recommendation:
Unlock the positions of components
- Problem:
Width of internal slots less than 0.8mm - Risk:
Industry minimum routing tool is 0.8mm, making machining impossible - Recommendation:
Design internal slots with a width greater than 0.8mm
- Problem:
Duplicate lines exist along the board edge - Risk:
May lead to incorrect board edge tolerances - Recommendation:
Ensure uniqueness of the board outline
