What is causing these holes to be filled up


#1

I have been working on a pcb design, and I just finished things, so I rendered the copper pour and found that some of my holes for tht components have been filled, like in this image:


Though it looks like a trace, it goes away when I press control-b and re-render the 3D board. Is this just a quirk that happens with the 3D model, or is something more worrisome happening, and will I need to worry about it if I order the board to be fabbed?


#2

Maybe you might want to check the gerber files with the gerber viewer.


#3

To be honest I have noticed the same and had the same concerns. @straubm is right. The Gerbers are the source of truth. In the end my boards, in my case, came back OK from the fab. So this is just a quirk with the 3D render.


#4

There are other quirks, too. So some tented vias are shown untented in the 3D renderer although they are correctly shown tented in a gerber viewer. Unless you have selected “do not tent vias” in the plotter, of course.


#5

For the 3d viewer there is an option to enable holes in zones.
It is under preferences->render options->show holes in zones.


#6

@Rene_Poschl: thx, didn’t know that.


#7

@Marsfan: A bit of topic but your zone seems to have very high clearance settings. Did you know that for zones you need to set it in the zone properties? The global settings are not used for zones.


#8

@Rene_Poschi I am a total beginner, what do you mean by there being high clearance zones?


#9

The clearance setting (of a zone) determines the distance between copper features of different nets. (example between gnd and any of your signals)
The clearance you can use is determined by your manufacturers capabilities and by the voltage you board is used for.

In the picture you posted there is quite a large distance between the zone and the tracks on your board.

You can change the clearance settings of your zone by pressing e while your mouse hovers above the outline of the zone. (On the left side of the properties window there are 2 settings. Clearance and minimum width.)
Normally you can set this stuff equal to what you use for everything else.
(preferences->drc settings.)

Again, check what your manufacturer is capable of. But i’m sure the standard settings for zones is much larger than what any normal fab can do.
(Zones start with approximately double to what the standard drc settings are.)

As far as i remember this tutorial explains these stuff quite well:


(Clearances are explained on page 9)


#10

@Rene_Poschl OSH Park does not list maximum clearances, I did not realize that there is a max for that, I will email them though, thanks.


#11

https://oshpark.com/guidelines

6 mil minimum trace width
6 mil minimum spacing (this is your minimum clearance)
at least 15 mil clearances from traces to the edge of the board
13 mil minimum drill size
7 mil minimum annular ring

There is no maximum. but small clearance means you could get connections where now there is no connection possible. This could significantly influence the ac behavior of your board. (could result in a shorter current return paths)


#12

@Rene_Poschl OK. That is why I will keep a larger clearance.