Hey guys I have some issue at PCB designing. Here I am going two set two adjacent holes for Pin L20 (on the left which is connected to power 2.5V)and L21. However, I can’t set the second hole on L21 after the first hole on L20 is placed. Is this because two holes are to close to each other ?
If yes how can I fix it ?
Thank you 
Hello @LF666
More information would be useful.
What is the footprint you are using?
Do you mean holes or vias?
What dimensions for vias are you using?
From the looks of it, your via is too big and you just can’t fit two of them together. For via’s the yellow hart is the hole, and the white thing is the annular ring. That means that if you put also a via on L21, they would touch each other without clearance.
To make this even more clear, you can turn on: PCB Editor / Preferences / Preferences / PCB Editor / Display Options / Clearance Outlines / Trach & Via Outlines / Show Always Clearances may overlap each other, but the clearance of one net may not overlap with copper of another net.
Sorry I didn’t choose my words correctly, I was talking about vias. And the dimension was showed in the comment zone. The footprint is MAX2082CXD+.
Hello, thanks for you suggestions. I have done the settings as you said, and now it shows like this. Is this a dimensions issue ?
Yes, as I wrote in my previous post, your via is to big to fit. Spend some time to learn what those lines and colors mean. It can also help if you view the result in KiCad’s 3D viewer [Alt + 3]. In the 3D viewer you can turn off layers and other settings to be able to focus better of your area of interest.
Do you have any prior experience with working with BGA’s? You can’t just use normal via’s on BGA pads. Via’s are hollow and they wick up the very limited amount on solder of the BGA ball, and this leaves not enough solder for a reliable connection.
Thank you very much, I don’t have any experice about it. Actually, I dont have any experience about PCB designing or Kicad, I am learning it all by myself.
You should not start learning PCB design from BGA.
I have never used BGA so don’t have opinion based on experience.
At your last picture the +2V5 via has a white circle showing that from some reason it has bigger clearance than other pads.
And also placing the via you made pad bigger then it was before.
I am using Vias on BGA pads because during the calbling I found out that I could only connect the fringer Pins without Vias, if a wire is going through a fringer Pin and connect to a inner Pin then a Via is necessary.
Actually I don’t have much choice, it is one project in my campus, the footprint is given, my job is designing a PCB for it. And my supervisor also don’t have much experience about it.
That IC has over 250 balls. Doing that as a beginners project is close to madness.
336 balls with a .8 mm pitch and quite some detailed information on layout concerns.
https://www.analog.com/media/en/package-pcb-resources/package/pkg_pdf/csbga/21-0639.pdf
The documents here https://docs.kicad.org/ will help you learn about Kicad, and it is best for you to learn about BGAs, and their placement, at school.
As a final comment from me, the dimensions for the via you showed in the Board Setup is the default minimum via dimensions.
The via dimension you displayed in your original screen grab can be found in Edit > Via Properties, hence my original question:
No, that is not what he meant.
That dialog is from PCB Editor / Edit / Set Track and Via Properties.
What he meant was: PCB Editor / File / Board Setup / Design Rules / Net Classes. With the net classes you can create a set of rules for Track and via sizes, clearances (and some more), which are then automatically used when you draw PCB tracks. (After both the net classes themselves, and the net class assignments to nets has been done). These are quite important parts of a PCB design. If you are not familiar with these, then go take a detour from your project and learn this first.
Thanks, I am working on it. 
Did I already warn you that a project of this size is not a good way to learn KiCad. Beginners are bound to make many mistakes because of lack of knowledge, and with a project of this size this often means you have to redo a lot of your work once you learned how to do it.
Yes, but it is part of my thesis. This project was just given to me, and I can’t reject it. I am watching some tutorials on youtube these days, and then see if I could go further on my current project. 
