Using vias to connect top and bottom ground planes

Thread Starter

Dritech

Joined Sep 21, 2011
863
Hi all,

I am using vias with thermal relief to connect the top and bottom ground planes together (design being done on Proteus)

Now I have the following concerns:

1) Is this a good method to use for connecting the top and bottom ground planes?
2) If I used these vias at different locations on the PCB (i.e. multiple points where the top and bottom planes are shorted), will this be bad practice?

Also, does anyone know how to cover these vias with solder mask? I managed to do this with all other vias, but for some reason, the vias being used to short the top anf bottom ground planes are not being covered by solder mask.

Any suggestions would be highly appreciated.

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jpanhalt

Joined Jan 18, 2008
9,420
Hi all,

I am using vias with thermal relief to connect the top and bottom ground planes together (design being done on Proteus)

Now I have the following concerns:

1) Is this a good method to use for connecting the top and bottom ground planes?
2) If I used these vias at different locations on the PCB (i.e. multiple points where the top and bottom planes are shorted), will this be bad practice?
Vias are what everyone uses. Moreover, they are almost always used at various locations on the PCB. Some people describe connecting top and bottom as "knitting" the two copper pours (usually ground) together. Look at datasheets for any device that produces significant heat, like a voltage regulator or battery charge ship. You will see several vias under the chip to spread the heat to a larger copper surface on the other side.

One thing to consider is whether you want to use thermals with your vias. Will you be soldering to them individually? Probably not. And thermals decrease thermal and electrical conductivity.

Also, does anyone know how to cover these vias with solder mask? I managed to do this with all other vias, but for some reason, the vias being used to short the top and bottom ground planes are not being covered by solder mask.
It's done both ways, tented and untented. There is also an option for solder filled. How yo intend to use the vias is what matters. If they might be used for test points, you want non-tented. Solder filled has its own purposes. One stated purpose is to avoid the via "sucking" solder from a pad and creating a weak solder joint.
 

dl324

Joined Mar 30, 2015
10,747
1) Is this a good method to use for connecting the top and bottom ground planes?
Leads connected to ground would normally do this, but there's nothing stopping you from adding more; particularly if it will help with thermal issues.
2) If I used these vias at different locations on the PCB (i.e. multiple points where the top and bottom planes are shorted), will this be bad practice?
Not in my opinion.
 
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