Eagle: via inside a pad, is it possible?

Newbie question, sorry if it's too basic for your guys. Trying to save some space/nets/soldering for an SMT board. Some of my devices are 1206 and larger (caps), and the size of the pads looks large enough to include a via inside. Besides, with the solder all over it there's not going to be a difference from the connection stand point. Can I just freely move vias around so that they end up INSIDE a device's position on a board, specifically its pad? Thanks for all your responses!

--
Dmitri Abaimov, RCDD
http://www.cabling-design.com
 Click to see the full signature
Reply to
Dmitri(Cabling-Design.com
Loading thread data ...

If the boar id to be hand soldered than go ahead. If it is to be reflowed than you should not do it because the solder paste will be forced through the via and it will make a mess on the other side.

Regards,

Boris Mohar

Got Knock? - see: Viatrack Printed Circuit Designs

formatting link

Reply to
Boris Mohar

Depends.. its not can you put a via inside a pad but how is the board getting built... if its automatically pick and place / wave etc.. then no... solder will flow down or up the via and tend to stand components upright or not solder them down properly. The only time its safe to use via in pad is if you use micro vias where the solder can't flow thru the via. Hand soldering makes it easier because you can simply add more solder until it works.

Simon

Reply to
Simon Peacock

I haven't tried it.

I'd expect it to work if you built a special package that had a pad and via touching eachother. The via would be a normal through hole via. You would probably have to connect that pin on the schematic to both the SMT pad and the via. After that, I'd expect the router to notice that they are connected and finish things by conecting the via to the right plane or routing a trace to it.

If you are manually adding vias to an existing layout, you need to connect the via to that net. (Should give design errors if you don't and put it in the middle of a SMT pad.)

If you don't make that connection, then the new via is part of a new net (or something like that) and the router will wire it to anything else on that net.

--
The suespammers.org mail server is located in California.  So are all my
other mailboxes.  Please do not send unsolicited bulk e-mail or unsolicited
 Click to see the full signature
Reply to
Hal Murray

Simon, Boris, Thank you for your responses!

I actually got more insight on the problem than I know what to do with ;-) I will be hand-soldering it for now, and will keep your comments in mind for the future if I have a chance to do a reflow on one of those boards.

My question was (I think) simpler: I don't seem to be able to make Eagle pickup on the vias placed inside the pads; they just seem to be ignored by the router. I'm not sure if it's a principal problem, and vias are just not expected to be inside the pads or I'm just not setting the router correctly. Honestly, I would not even know which setting would I have to play with to make it recognize the vias.

So, if an Eagle guru happens to read this, I'm still looking for a solution ;-)

Thanks again!

--
Dmitri Abaimov, RCDD
http://www.cabling-design.com
 Click to see the full signature
Reply to
Dmitri(Cabling-Design.com

there should be no problem doing this in Eagle, although it will flag up a DRC error. If you are struggling to place it on the pad then the problem is likely to be you grid settings. Change to a finer grid size, or use a fine alt grid, such that the pad lies on the grid.

For access to all the Eagle gurus check out the eagle newsgroups, this link on the cadsoft website should allow you to set things up.

formatting link

The support groups are fairly active, and most of your future queries will have come up at some time before so have a scan over the older meaasges if you've got any other queries.

cheers

David

Reply to
David M

Hi David,

Thank you for the link. Will definitely take a look at their messages archive!

--
Dmitri Abaimov, RCDD
http://www.cabling-design.com
 Click to see the full signature
Reply to
Dmitri(Cabling-Design.com

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.