What's the meaning of the red circle?

[iyysheng]

I find there is always a fine red circle around the pad in a bga footprint coponent in the picture as below:

what’s the fine red circle mean ?how could i modify the circle’s radius?

[paulvdh]

The circle indicates the clearance of the net. It is the area in which no tracks from other nets are allowed. You can adjust this by setting the properties of the nets or setting up net classes and putting your nets in those net classes.

You can also enable and disable the visibility of clearances in **PCB Editor / Preferences / Preferences / PCB Editor / Display Options / Clearance Outlines.

[iyysheng]

yeah, thanks for your reply.

[iyysheng]

Hello @paulvdh, I can modify the pad clearance in footprint editor.

But I couldn’t find how to modify the pad clearance in board setup rules,

[paulvdh]

A small cutout from your own screenshot:

And a bit of parroting from 3 days ago:

@paulvdh

You can adjust this by setting the properties of the nets or setting up net classes and putting your nets in those net classes.

For more info, open the help file of the PCB editor, and then search for keywords such as “clearance” or “net class” and start reading.

[iyysheng]

@paulvdh

clearance

I tried seach in board design rule:

or netclass rule

I’m not sure which paramter can change the pad clearance.

[paulvdh]

So, apparently you’ve already set up some net classes. (That’s good).

The clearance for the pads is the same as the clearance for the tracks, or for the whole net. That means:

However, the clearance of the net class is only used if you do not set the clearance in the footprints themselves. If you set it in a footprint, or manually set it for a pad in the PCB Editor then that overrules the clearance for the net class.

You can also make the clearance for the tracks visible with: PCB Editor / Preferences / Preferences / PCB Editor / Display Options / Clearance Outlines

[iyysheng]

very thanks, I understand. @paulvdh