Eagle: via inside a pad, is it possible?

  • Thread starter Dmitri(Cabling-Design.com
  • Start date
D

Dmitri(Cabling-Design.com

Guest
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
Cabling Forum, color codes, pinouts and other useful resources for
premises cabling users and pros
http://www.cabling-design.com/homecabling
Residential Cabling Guide
-------------------------------------


##-----------------------------------------------##
Article posted with Cabling-Design.com Newsgroup Archive
http://www.cabling-design.com/forums
no-spam read and post WWW interface to your favorite newsgroup -
sci.electronics.cad - 3157 messages and counting!
##-----------------------------------------------##
 
David M wrote:

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.
http://www.cadsoft.de/forum.htm

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
Click to expand...
Hi David,

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

--
Dmitri Abaimov, RCDD
http://www.cabling-design.com
Cabling Forum, color codes, pinouts and other useful resources for
premises cabling users and pros
http://www.cabling-design.com/homecabling
Residential Cabling Guide
-------------------------------------







##-----------------------------------------------##
Article posted with Cabling-Design.com Newsgroup Archive
http://www.cabling-design.com/forums
no-spam read and post WWW interface to your favorite newsgroup -
sci.electronics.cad - 3201 messages and counting!
##-----------------------------------------------##
 
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


"Dmitri(Cabling-Design.com)" <info_at_cabling-design_dot_com@foo.com> wrote
in message news:eek:sPsd.4162951$yk.628278@news.easynews.com...
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
Cabling Forum, color codes, pinouts and other useful resources for
premises cabling users and pros
http://www.cabling-design.com/homecabling
Residential Cabling Guide
-------------------------------------


##-----------------------------------------------##
Article posted with Cabling-Design.com Newsgroup Archive
http://www.cabling-design.com/forums
no-spam read and post WWW interface to your favorite newsgroup -
sci.electronics.cad - 3157 messages and counting!
##-----------------------------------------------##
Click to expand...
 
On Mon, 06 Dec 2004 02:27:32 GMT, info_at_cabling-design_dot_com@foo.com
(Dmitri(Cabling-Design.com)) wrote:

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!
Click to expand...
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 http://www3.sympatico.ca/borism/
 
Simon Peacock wrote:

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
Simon, Boris, Thank you for your responses!
Click to expand...

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
Cabling Forum, color codes, pinouts and other useful resources for
premises cabling users and pros
http://www.cabling-design.com/homecabling
Residential Cabling Guide
-------------------------------------


##-----------------------------------------------##
Article posted with Cabling-Design.com Newsgroup Archive
http://www.cabling-design.com/forums
no-spam read and post WWW interface to your favorite newsgroup -
sci.electronics.cad - 3179 messages and counting!
##-----------------------------------------------##
 
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.
Click to expand...
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
commercial e-mail to my suespammers.org address or any of my other addresses.
These are my opinions, not necessarily my employer's. I hate spam.
 
Dmitri(Cabling-Design.com) wrote:
Simon Peacock wrote:


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

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!
Click to expand...
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.
http://www.cadsoft.de/forum.htm

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
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top