Copper pours and Thermals

Thread Starter

gautam023

Joined Apr 26, 2021
16
Hello everyone,

I am designing a power supply board from a 72V battery pack using LT3958 (datasheet here) in SEPIC configuration. For SW node and GND connections, I used a copper pour without any thermals. This was because, when I used thermals the pour was not surrounding the pads. Is it safe to remove thermals from large pours? See attached pics for ref.
 

Attachments

Hemi

Joined Mar 17, 2012
20
Yes, but might be difficult to solder depending on soldering method. I would remove them from the vias as well.
 

djsfantasi

Joined Apr 11, 2010
7,700
I don’t understand why the pour didn’t surround the pad?
Depending on the PCB software you are using, a thermal won’t connect unless the thermal has the same net as the pour.
You can easily change this in the thermal properties by assigning the thermal the same net as the pour.
 

Hemi

Joined Mar 17, 2012
20
In Eagle, thermals are an option for each pour. I usually always enable them and then, where needed, use either big fat traces or an additional pour without thermals enabled where I want high current traces or additional heatsinking.
 
Top