PCB Terms

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allenpitts
Posts: 17
Joined: 29 Sep 2017, 20:03

PCB Terms

#1 Post by allenpitts » 03 Apr 2020, 14:35

Hello Dip Trace Forum,

Have been designing and ordering PCBs for several years
but there are some terms that elude me. These
two are most confusing:

1. Annular ring {isn't that on a tree?) Googled this
and got
'that portion of conductive material completely surrounding a hole.'
and in another place
'Conductive material surrounding a hole which creates a pad. '
So what's the difference between an annular ring and a pad?
Or is there a difference?

2. Ratline Googled this and can't find anything.
What is a ratline?

Thanks.

Allen in Dallas

Tomg
Expert
Posts: 1524
Joined: 20 Jun 2015, 14:39

Re: PCB Terms

#2 Post by Tomg » 03 Apr 2020, 17:34

Annular Ring: https://www.protoexpress.com/pcb/learn- ... ing-width/

Ratline: A temporary line in the PCB Layout editor that shows a net connection. It is not a trace. It is a guide to help the designer lay down a trace to connect two pads belonging to the same net. When the trace has been completed the associated ratline will disappear, indicating a successful copper connection. All of the ratlines make up what is commonly referred to as the "rats nest".
Tom

allenpitts
Posts: 17
Joined: 29 Sep 2017, 20:03

Re: PCB Terms

#3 Post by allenpitts » 03 Apr 2020, 18:52

Hello Tomg,

Excellent explanation.

AT the annular ring URL it says'
'An annular ring is the area on the pad that surrounds a through via.'
Again, I think I know what a 'via' is but not absolutely sure. So Binged that.
'Vias are the means to interconnect different layers on and within the multilayered PCBs'
So a via is a copper cylinder the diameter of the hole in the pad or annular ring
which connects all the traces that intersect that hole. Right?

Thanks.

Allen in Dallas

PS I used to spin my toilet paper roll like it was the
Wheel of Fortune. Now I spin it like I am cracking a safe.

Tomg
Expert
Posts: 1524
Joined: 20 Jun 2015, 14:39

Re: PCB Terms

#4 Post by Tomg » 03 Apr 2020, 20:43

Think of a via as a small, through-hole pad. There is a recommended minimum ring size which may vary between each board house. Standard vias go all the way through the PCB. Blind vias can start out on either the top or bottom layer and terminate on an internal layer without exiting the PCB on the opposite side. Buried vias connect only inner layers and are not visible on either side of the PCB...
https://www.protoexpress.com/pcb/learn- ... -pcb-vias/
Tom

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