Topic: Via questions

Via questions
A couple of questions about vias on 4/6 layer boards:

1. Does a via need a copper annular ring on layers where there is no trace/plane connecting to the via?

2. If I put a via in a pad, is the via filled to stop solder wicking into the via or do I need to make allowance for wicking when soldering?

Also, do you have recommended trace widths / separations for 50-ohm single ended and 100-ohm differential traces?
10/08/2012 21:48:09
Ralph Loader
Re: Via questions
Hi Ralph,
In answer to your questiona
1. We recommend that you put a copper pad on all layers for vias.
2. If you place a via on a pad then this via will be filled with solder during the finishing process. I am not sure what you mean by "wicking" but I imagine you will need to make some allowance.
3. Please have a look at the downloads section on our services page. You may find something to help you here. We dont have any official recomendations for this.

Best Regards
Your Pcb-Pool Team
15/08/2012 08:53:03
Beta LAYOUT Ltd Service Team