Anyone have experience with 10 mil via holes and reliability issues?
If you have a problem with an order like this, is it reasonable to use
one panel and reject the rest?

Anyone have experience with 10 mil via holes and reliability issues?
If you have a problem with an order like this, is it reasonable to use
one panel and reject the rest?

As you have figured-out, pushing the process limit could be
expensive. We would not go below 16 mil holes, even if we need bigger
boards. Are you sure you can't use bigger holes?

On Apr 10, 11:26 am, linnix <m...@linnix.info-for.us> wrote:
Anyone have experience with 10 mil via holes and reliability issues?
If you have a problem with an order like this, is it reasonable to use
one panel and reject the rest?

As you have figured-out, pushing the process limit could be
expensive. We would not go below 16 mil holes, even if we need bigger
boards. Are you sure you can't use bigger holes?

Sure, I can use bigger holes. But I can't use bigger pads. It was
hard enough to make the layout work with 10 mil holes and 24 mil
pads. This board is very small and defined by the customer's
requirements. It is a daughter card on an existing product so I have
no flexibility in size except for extending one end which I have
already done as much as possible. Even that does not do a lot for the
density issue since the board is over 5 times longer than it is wide.
Extending the length more just means I have longer lines to try to
squeeze through the same bottlenecks around the chips and
connectors.

I guess I am confused about "process limits". I have seen vendors
that claim to have capability for hole sizes down to 6 mil. They just

say that they can't guarantee that the hole will not be plated closed
which is fine with me. So I don't see where 10 mil holes should be a
real issue. Did I pick a poor PCB maker? Am I just not grasping the
realities of PCB manufacturing?

"rickman" <gnu...@gmail.com> wrote in messagenews:e635a429-c2c9-409c-a284-73e57abac57d@p25g2000hsf.googlegroups.com...
Anyone have experience with 10 mil via holes and reliability issues?
If you have a problem with an order like this, is it reasonable to use
one panel and reject the rest?

I had problems with a vendor once, it was "weak" vias. They were 20mils
though, done on early ROHS process. And yes, baking boards twice
for smd and through-hole did create new broken vias, some immediately
and some later. If I knew about this, I'd toss entire batch right away.
Caused quite a big of grief. I ask my vendor now to leave them a bit
longer in the metalization "soup" and he had to compensate for part of the
damage (tarnished name can't be restored so easily).

You can try baking boards without components and than passing them
through tester again, make sure testing current is set to high"ish" level.

Mark

"rickman" <gnuarm@gmail.com> wrote in message
news:b54bdd8a-f575-4a41-a4f1-888f600fe515@k13g2000hse.googlegroups.com...
On Apr 10, 11:26 am, linnix <m...@linnix.info-for.us> wrote:
Anyone have experience with 10 mil via holes and reliability issues?
If you have a problem with an order like this, is it reasonable to use
one panel and reject the rest?

As you have figured-out, pushing the process limit could be
expensive. We would not go below 16 mil holes, even if we need bigger
boards. Are you sure you can't use bigger holes?

Sure, I can use bigger holes. But I can't use bigger pads. It was
hard enough to make the layout work with 10 mil holes and 24 mil
pads. This board is very small and defined by the customer's
requirements. It is a daughter card on an existing product so I have
no flexibility in size except for extending one end which I have
already done as much as possible. Even that does not do a lot for the
density issue since the board is over 5 times longer than it is wide.
Extending the length more just means I have longer lines to try to
squeeze through the same bottlenecks around the chips and
connectors.

I guess I am confused about "process limits". I have seen vendors
that claim to have capability for hole sizes down to 6 mil. They just

Did the vendor you chose give this claim? If not then there's your
problem, choose a different vendor.

say that they can't guarantee that the hole will not be plated closed
which is fine with me. So I don't see where 10 mil holes should be a
real issue. Did I pick a poor PCB maker? Am I just not grasping the
realities of PCB manufacturing?

On Apr 10, 11:26 am, linnix <m...@linnix.info-for.us> wrote:
Anyone have experience with 10 mil via holes and reliability issues?
If you have a problem with an order like this, is it reasonable to use
one panel and reject the rest?

As you have figured-out, pushing the process limit could be
expensive. We would not go below 16 mil holes, even if we need bigger
boards. Are you sure you can't use bigger holes?

Sure, I can use bigger holes. But I can't use bigger pads. It was
hard enough to make the layout work with 10 mil holes and 24 mil
pads. This board is very small and defined by the customer's
requirements. It is a daughter card on an existing product so I have
no flexibility in size except for extending one end which I have
already done as much as possible. Even that does not do a lot for the
density issue since the board is over 5 times longer than it is wide.
Extending the length more just means I have longer lines to try to
squeeze through the same bottlenecks around the chips and
connectors.

I guess I am confused about "process limits". I have seen vendors
that claim to have capability for hole sizes down to 6 mil. They just
say that they can't guarantee that the hole will not be plated closed
which is fine with me. So I don't see where 10 mil holes should be a
real issue. Did I pick a poor PCB maker? Am I just not grasping the
realities of PCB manufacturing?

I had some PCBs made with 22 boards per panel (small boards). I
wanted a single panel for prototypes, but it turned out I could get 6
panels for only $500 more. This would get me through the first round
of production if I didn't need any changes. The day the maker was
supposed to ship them, I got an email saying they had a poor yield and
only got 116 good boards out of 7 panels vs the 132 I ordered.

So now I have a concern about the quality of the boards. I was told
the failed boards had problems with the plating in the 10 mil holes I
used for vias. They claim that the "good" boards have no quality
issues. My concern is that the vias may be marginal and open once
they are temperature cycled a bit.

I am not sure how to handle this with the vendor. I guess I could
just flat out tell them that I am concerned with investing some
$18,000 building up over 100 boards only to have my customer see
failures in the field. I don't feel like they have done 100% on this
since they did not provide the quantity I requested.

They have offered to rebuild the entire set of panels if I am not
happy with the result, but that would be a week delay. I also don't
know if they are willing to let me use one of the current panels and
remake the rest.

Anyone have experience with 10 mil via holes and reliability issues?
If you have a problem with an order like this, is it reasonable to use
one panel and reject the rest?

Anyone have experience with 10 mil via holes and reliability issues?
If you have a problem with an order like this, is it reasonable to use
one panel and reject the rest?

On Thu, 10 Apr 2008 08:18:41 -0700 (PDT), rickman <gnuarm@gmail.com
wrote:

I had some PCBs made with 22 boards per panel (small boards). I
wanted a single panel for prototypes, but it turned out I could get 6
panels for only $500 more. This would get me through the first round
of production if I didn't need any changes. The day the maker was
supposed to ship them, I got an email saying they had a poor yield and
only got 116 good boards out of 7 panels vs the 132 I ordered.

So now I have a concern about the quality of the boards. I was told
the failed boards had problems with the plating in the 10 mil holes I
used for vias. They claim that the "good" boards have no quality
issues. My concern is that the vias may be marginal and open once
they are temperature cycled a bit.

I am not sure how to handle this with the vendor. I guess I could
just flat out tell them that I am concerned with investing some
$18,000 building up over 100 boards only to have my customer see
failures in the field. I don't feel like they have done 100% on this
since they did not provide the quantity I requested.

They have offered to rebuild the entire set of panels if I am not
happy with the result, but that would be a week delay. I also don't
know if they are willing to let me use one of the current panels and
remake the rest.

Anyone have experience with 10 mil via holes and reliability issues?
If you have a problem with an order like this, is it reasonable to use
one panel and reject the rest?

At least they have a good enough quality control that they can spot
this problem. You can have them do a cross section of a good board to
see if the vias look healthy.

Plating systems have to be top-notch to handle small via sizes. If the
board house hasn't kept up on updating their equipment, they will have
problems with small features.

I routinely use 8mil drill with 15mil pads. The pad size is marginal,
but the four board houses I have used never had problems with that via
size for the past 5 to 8 years.

There is one case back in the early 90s where the plated through holes
would disconnect when moderate current (apx 1 amp) passed thru the
plated hole after soldering. Before soldering, the PTH handled 10A,
after soldering it would blow around 1A. Most of the bypass caps
disconnected at power up.

---
Mark
Hi Mark,

On Apr 10, 1:41 pm, "TheM" <DontNeedS...@test.com> wrote:

Thanks for your suggestion. I thought of that, but I don't have a way
to test the bare boards. Turns out I have four more weeks to order
the panels, so I have some time to evaluate the boards in the
prototypes.

"qrk" <SpamTrap@spam.net> wrote in message
news:0kjsv31ir5f1470ho8j8ampu79gie96nae@4ax.com...
On Thu, 10 Apr 2008 08:18:41 -0700 (PDT), rickman <gnuarm@gmail.com
wrote:

I had some PCBs made with 22 boards per panel (small boards). I
wanted a single panel for prototypes, but it turned out I could get 6
panels for only $500 more. This would get me through the first round
of production if I didn't need any changes. The day the maker was
supposed to ship them, I got an email saying they had a poor yield and
only got 116 good boards out of 7 panels vs the 132 I ordered.

So now I have a concern about the quality of the boards. I was told
the failed boards had problems with the plating in the 10 mil holes I
used for vias. They claim that the "good" boards have no quality
issues. My concern is that the vias may be marginal and open once
they are temperature cycled a bit.

I am not sure how to handle this with the vendor. I guess I could
just flat out tell them that I am concerned with investing some
$18,000 building up over 100 boards only to have my customer see
failures in the field. I don't feel like they have done 100% on this
since they did not provide the quantity I requested.

They have offered to rebuild the entire set of panels if I am not
happy with the result, but that would be a week delay. I also don't
know if they are willing to let me use one of the current panels and
remake the rest.

Anyone have experience with 10 mil via holes and reliability issues?
If you have a problem with an order like this, is it reasonable to use
one panel and reject the rest?

At least they have a good enough quality control that they can spot
this problem. You can have them do a cross section of a good board to
see if the vias look healthy.

Plating systems have to be top-notch to handle small via sizes. If the
board house hasn't kept up on updating their equipment, they will have
problems with small features.

I routinely use 8mil drill with 15mil pads. The pad size is marginal,
but the four board houses I have used never had problems with that via
size for the past 5 to 8 years.

There is one case back in the early 90s where the plated through holes
would disconnect when moderate current (apx 1 amp) passed thru the
plated hole after soldering. Before soldering, the PTH handled 10A,
after soldering it would blow around 1A. Most of the bypass caps
disconnected at power up.

---
Mark
Hi Mark,
Have you done any PTH vias (0.012"D) that are in SMT solder pads that are
filled either with a non conductive material before the solder is added? I
have done this on a couple of jobs recently and it simplifies layout and the
vias used for thermal flow, let's say six under a DD Pac work great.
What say you?
Harry

"rickman" <gnu...@gmail.com> wrote in messagenews:c9e9e9eb-c180-420a-a160-1cc6c87ffcd3@d1g2000hsg.googlegroups.com...
On Apr 10, 1:41 pm, "TheM" <DontNeedS...@test.com> wrote:
Thanks for your suggestion. I thought of that, but I don't have a way
to test the bare boards. Turns out I have four more weeks to order
the panels, so I have some time to evaluate the boards in the
prototypes.

PCB vendor surely has a machine to check for continuity, even the cheap
vendors do. Ask them.

Mark
Hi Mark,
Have you done any PTH vias (0.012"D) that are in SMT solder pads that are
filled either with a non conductive material before the solder is added?
I
have done this on a couple of jobs recently and it simplifies layout and
the
vias used for thermal flow, let's say six under a DD Pac work great.
What say you?
Harry

We have used filled vias for a different reason, to get more space in
a tight layout. Really strange to see pads with no visible drill hole!
I normally avoid filled vias due to extra cost. When I put thermal
vias under a Dpak, I make sure there's enough solder paste to fill the
via. The pad, or Cu pour, on the opposite side of the board is mostly
covered with soldermask, but the via drill hole isn't tented so the
via can burp. I usually use around 50 to 70% pad coverage for
solderpaste, depending on the part and/or if I use thermal vias in the
body pad.

Harry, I've been having fun making switching supplies recently. Made a
50W forward converter and, something we chatted about briefly a few
years ago, a SEPIC switcher to charge up a capacitor bank with
constant current for a pulse amplifier. Both run at 600kHz. The new
controllers sure make life easy. Both these supplies used the
technique above for the power components thermal vias.

---
Mark
Thanks Mark, not many of us left.

On Apr 10, 5:54 pm, "TheM" <DontNeedS...@test.com> wrote:
"rickman" <gnu...@gmail.com> wrote in messagenews:c9e9e9eb-c180-420a-a160-1cc6c87ffcd3@d1g2000hsg.googlegroups.com...
On Apr 10, 1:41 pm, "TheM" <DontNeedS...@test.com> wrote:
Thanks for your suggestion. I thought of that, but I don't have a way
to test the bare boards. Turns out I have four more weeks to order
the panels, so I have some time to evaluate the boards in the
prototypes.

PCB vendor surely has a machine to check for continuity, even the cheap
vendors do. Ask them.

You are suggesting that I temperature cycle the boards a few times and
send the blank boards back to the vendor for retest? I guess that is
an idea. So far they have been a bit difficult to communicate with.
I shouldn't say "difficult", just very slow getting answers from
them. I ask a question and it seems to require a lot of research to
get an answer. Then I hear back after a day or so. It is like they
don't seem to feel like they screwed up and are not making any real
effort to help me deal with the resulting repercussions.

I'll give them until tomorrow (Friday) to get back to me with
something substantial. If we don't have some sort of dialog going
that is likely to result in an improvement in my satisfaction, I will
just cut my losses and move on. I need to keep my customer happy and
I can't do that with an unresponsive vendor.