Landless vias (PCB)

S

Spehro Pefhany

Guest
Any experience (positive or negative) with these?

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
Spehro,
Maybe you can explain precisely what you mean by "landless via"?

I am thinking a plated via hole with a trace connecting to an edge of
that plated hole, no pad extending past the plated hole edge. Not reliable
against everything that I been taught! Wouldn't it crack along that 90
degree trace/via boundary very easily? Not to mention, this would also make
the plated barrels less constrained and prone to loosening or pulling out?

--
Sincerely,
Brad Velander

"Spehro Pefhany" <speffSNIP@interlogDOTyou.knowwhat> wrote in message
news:0vnb60doolrj8o9ipvegjlib08mqq4sqoj@4ax.com...
Any experience (positive or negative) with these?

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers:
http://www.trexon.com
Embedded software/hardware/analog Info for designers:
http://www.speff.com
Click to expand...
 
On Sun, 28 Mar 2004 03:59:15 GMT, the renowned "Brad Velander"
<spamthis@nowhere.com> wrote:

Spehro,
Maybe you can explain precisely what you mean by "landless via"?

I am thinking a plated via hole with a trace connecting to an edge of
that plated hole, no pad extending past the plated hole edge. Not reliable
against everything that I been taught! Wouldn't it crack along that 90
degree trace/via boundary very easily? Not to mention, this would also make
the plated barrels less constrained and prone to loosening or pulling out?
Click to expand...

See page 5 of this PDF, figure 2. Pulling out shouldn't be an issue
with vias, but cracking at the edge might well be. I've seen open vias
in 2-layer PCBs in the not too distant past.

http://corporate.ppg.com/ppg/indcoat/electrprod/documents/HDIConf2000ex.pdf

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
Thanks Spehro,
Yes that is what I was think of when you first mentioned it. It
certainly goes against most everything that I have ever been taught about
PCB reliability.

--
Sincerely,
Brad Velander

"Spehro Pefhany" <speffSNIP@interlogDOTyou.knowwhat> wrote in message
news:srkc609tltdc3pv7ss4rsbtqa3g3uf745f@4ax.com...
See page 5 of this PDF, figure 2. Pulling out shouldn't be an issue
with vias, but cracking at the edge might well be. I've seen open vias
in 2-layer PCBs in the not too distant past.


http://corporate.ppg.com/ppg/indcoat/electrprod/documents/HDIConf2000ex.pdf

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers:
http://www.trexon.com
Embedded software/hardware/analog Info for designers:
http://www.speff.com
Click to expand...
 
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