Re: [time-nuts] HP 5065A super
Here is ENIG fact that is not widely known at the moment but which some might find useful.
I could not understand why I get better TDR and insertion loss results from solder-mask covered microstrip transmission lines than from otherwise identical microstrips on the same substrate with soldermask removed and, therefore, covered with ENIG.
Gold can't be bad, right? As it turns out, even gold coin has two sides to it.
I have found that Shlepnev and McMorrow conducted extensive research and published data, some of which is presented here http://www.simberian.com/Presentations/NickelCharacterizationPresentation_emc2011.pdf
In essence, it's not the "G" that is the problem - it is the "N".
Immersion Gold layer is not thick enough to contain whole of the skin effect layer (even towards 100GHz) and as signal frequency increases most of the signal ends up travelling through Nickel.
As Shlepnev commented "Nickel is the most mysterious metal in electronics." It has significant effect on insertion loss and risetime degradation. "Significant effect" is posh for "bad."
Some mass PCB manufacturers have been known to apply ENIG before soldermasking. This causes even more high speed/frequency problems because all of the copper on the outside layers will have Nickel over it - exposed or not.
Probably not a problem for majority of ENIG users but could cause a headache or two for unsuspecting.
Leo
Date: Thu, 22 Feb 2018 19:02:25 +0000
From: Mark Sims holrum@hotmail.com
Yes, have the board done with ENIG gold. It typically adds around $15 per run of boards. I do all my boards with ENIG gold... if for no other reason than the gold color makes it very easy to determine when your solder paste properly covers the pads.
And, as Charles mentioned, the quality and thickness of the gold can vary depending upon the board house. I have used gojgo.com for a lot of boards. They do very good, quick work, are well priced, and they seem to have the best gold finish.
Hard gold finish is VERY expensive these days. I've been quoted $250+ for setup charges and per-board costs of over $25.
In general it's bad practice to gold plate SMT solder pads. The reason is
that proper SMT soldering utilizes a very small amount of solder and the
gold plating
will partially dissolve into the molten solder. Because of the small amount
of
solder, the percentage of gold will be high enough to embrittle the solder
joint,
and it will have a high probability of failure.
Hand soldering can apply a large enough amount of solder that the percentage
of gold in the joint is relatively small and the problem is avoided.
-- Tom, N5EG
On Thu, Feb 22, 2018 at 12:29 PM, Leo Bodnar leo@leobodnar.com wrote:
Here is ENIG fact that is not widely known at the moment but which some
might find useful.
I could not understand why I get better TDR and insertion loss results
from solder-mask covered microstrip transmission lines than from otherwise
identical microstrips on the same substrate with soldermask removed and,
therefore, covered with ENIG.
Gold can't be bad, right? As it turns out, even gold coin has two sides to
it.
I have found that Shlepnev and McMorrow conducted extensive research and
published data, some of which is presented here http://www.simberian.com/
Presentations/NickelCharacterizationPresentation_emc2011.pdf
In essence, it's not the "G" that is the problem - it is the "N".
Immersion Gold layer is not thick enough to contain whole of the skin
effect layer (even towards 100GHz) and as signal frequency increases most
of the signal ends up travelling through Nickel.
As Shlepnev commented "Nickel is the most mysterious metal in
electronics." It has significant effect on insertion loss and risetime
degradation. "Significant effect" is posh for "bad."
Some mass PCB manufacturers have been known to apply ENIG before
soldermasking. This causes even more high speed/frequency problems because
all of the copper on the outside layers will have Nickel over it - exposed
or not.
Probably not a problem for majority of ENIG users but could cause a
headache or two for unsuspecting.
Leo
Date: Thu, 22 Feb 2018 19:02:25 +0000
From: Mark Sims holrum@hotmail.com
Yes, have the board done with ENIG gold. It typically adds around $15
per run of boards. I do all my boards with ENIG gold... if for no other
reason than the gold color makes it very easy to determine when your solder
paste properly covers the pads.
And, as Charles mentioned, the quality and thickness of the gold can
vary depending upon the board house. I have used gojgo.com for a lot of
boards. They do very good, quick work, are well priced, and they seem to
have the best gold finish.
Hard gold finish is VERY expensive these days. I've been quoted $250+
for setup charges and per-board costs of over $25.
time-nuts mailing list -- time-nuts@febo.com
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mailman/listinfo/time-nuts
and follow the instructions there.
My reading of IPC J-STD-001F Paragraph 4.5 says that the gold embrittlement
issue does not apply to ENIG or ENEPIG. Paragraph 4.5.1 does say other gold
shall be removed so there won't be solder embrittlement.
Is that still correct?
The issue with ENIG and RF is interesting. I have not heard that before but
I can find lots of info on the subject. I do not remember seeing ENIG on
microstrip boards.
Regards,
Mark
On Thu, Feb 22, 2018 at 2:33 PM, Tom McDermott tom.n5eg@gmail.com wrote:
In general it's bad practice to gold plate SMT solder pads. The reason is
that proper SMT soldering utilizes a very small amount of solder and the
gold plating
will partially dissolve into the molten solder. Because of the small amount
of
solder, the percentage of gold will be high enough to embrittle the solder
joint,
and it will have a high probability of failure.
Hand soldering can apply a large enough amount of solder that the
percentage
of gold in the joint is relatively small and the problem is avoided.
-- Tom, N5EG
On Thu, Feb 22, 2018 at 12:29 PM, Leo Bodnar leo@leobodnar.com wrote:
Here is ENIG fact that is not widely known at the moment but which some
might find useful.
I could not understand why I get better TDR and insertion loss results
from solder-mask covered microstrip transmission lines than from
otherwise
identical microstrips on the same substrate with soldermask removed and,
therefore, covered with ENIG.
Gold can't be bad, right? As it turns out, even gold coin has two sides
to
it.
I have found that Shlepnev and McMorrow conducted extensive research and
published data, some of which is presented here
Presentations/NickelCharacterizationPresentation_emc2011.pdf
In essence, it's not the "G" that is the problem - it is the "N".
Immersion Gold layer is not thick enough to contain whole of the skin
effect layer (even towards 100GHz) and as signal frequency increases most
of the signal ends up travelling through Nickel.
As Shlepnev commented "Nickel is the most mysterious metal in
electronics." It has significant effect on insertion loss and risetime
degradation. "Significant effect" is posh for "bad."
Some mass PCB manufacturers have been known to apply ENIG before
soldermasking. This causes even more high speed/frequency problems
because
all of the copper on the outside layers will have Nickel over it -
exposed
or not.
Probably not a problem for majority of ENIG users but could cause a
headache or two for unsuspecting.
Leo
Date: Thu, 22 Feb 2018 19:02:25 +0000
From: Mark Sims holrum@hotmail.com
Yes, have the board done with ENIG gold. It typically adds around $15
per run of boards. I do all my boards with ENIG gold... if for no other
reason than the gold color makes it very easy to determine when your
solder
paste properly covers the pads.
And, as Charles mentioned, the quality and thickness of the gold can
vary depending upon the board house. I have used gojgo.com for a lot of
boards. They do very good, quick work, are well priced, and they seem
to
have the best gold finish.
Hard gold finish is VERY expensive these days. I've been quoted $250+
for setup charges and per-board costs of over $25.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/
mailman/listinfo/time-nuts
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ailman/listinfo/time-nuts
and follow the instructions there.
It appears that ENIG gold is extremely thin (2 - 8 microinches),
and if so does not cause a solderability problem.
-- Tom, N5EG
On Thu, Feb 22, 2018 at 3:18 PM, Mark Goldberg marklgoldberg@gmail.com
wrote:
My reading of IPC J-STD-001F Paragraph 4.5 says that the gold embrittlement
issue does not apply to ENIG or ENEPIG. Paragraph 4.5.1 does say other gold
shall be removed so there won't be solder embrittlement.
Is that still correct?
The issue with ENIG and RF is interesting. I have not heard that before but
I can find lots of info on the subject. I do not remember seeing ENIG on
microstrip boards.
Regards,
Mark
On Thu, Feb 22, 2018 at 2:33 PM, Tom McDermott tom.n5eg@gmail.com wrote:
In general it's bad practice to gold plate SMT solder pads. The reason
is
that proper SMT soldering utilizes a very small amount of solder and the
gold plating
will partially dissolve into the molten solder. Because of the small
amount
of
solder, the percentage of gold will be high enough to embrittle the
solder
joint,
and it will have a high probability of failure.
Hand soldering can apply a large enough amount of solder that the
percentage
of gold in the joint is relatively small and the problem is avoided.
-- Tom, N5EG
On Thu, Feb 22, 2018 at 12:29 PM, Leo Bodnar leo@leobodnar.com wrote:
Here is ENIG fact that is not widely known at the moment but which some
might find useful.
I could not understand why I get better TDR and insertion loss results
from solder-mask covered microstrip transmission lines than from
otherwise
identical microstrips on the same substrate with soldermask removed
and,
therefore, covered with ENIG.
Gold can't be bad, right? As it turns out, even gold coin has two sides
to
it.
I have found that Shlepnev and McMorrow conducted extensive research
and
published data, some of which is presented here
Presentations/NickelCharacterizationPresentation_emc2011.pdf
In essence, it's not the "G" that is the problem - it is the "N".
Immersion Gold layer is not thick enough to contain whole of the skin
effect layer (even towards 100GHz) and as signal frequency increases
most
of the signal ends up travelling through Nickel.
As Shlepnev commented "Nickel is the most mysterious metal in
electronics." It has significant effect on insertion loss and risetime
degradation. "Significant effect" is posh for "bad."
Some mass PCB manufacturers have been known to apply ENIG before
soldermasking. This causes even more high speed/frequency problems
because
all of the copper on the outside layers will have Nickel over it -
exposed
or not.
Probably not a problem for majority of ENIG users but could cause a
headache or two for unsuspecting.
Leo
Date: Thu, 22 Feb 2018 19:02:25 +0000
From: Mark Sims holrum@hotmail.com
Yes, have the board done with ENIG gold. It typically adds around
$15
per run of boards. I do all my boards with ENIG gold... if for no
other
reason than the gold color makes it very easy to determine when your
solder
paste properly covers the pads.
And, as Charles mentioned, the quality and thickness of the gold can
vary depending upon the board house. I have used gojgo.com for a lot
of
boards. They do very good, quick work, are well priced, and they seem
to
have the best gold finish.
Hard gold finish is VERY expensive these days. I've been quoted
$250+
for setup charges and per-board costs of over $25.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/
mailman/listinfo/time-nuts
and follow the instructions there.
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To unsubscribe, go to https://www.febo.com/cgi-bin/m
ailman/listinfo/time-nuts
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To unsubscribe, go to https://www.febo.com/cgi-bin/
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and follow the instructions there.
On 2/22/18 12:29 PM, Leo Bodnar wrote:
Here is ENIG fact that is not widely known at the moment but which some might find useful.
I could not understand why I get better TDR and insertion loss results from solder-mask covered microstrip transmission lines than from otherwise identical microstrips on the same substrate with soldermask removed and, therefore, covered with ENIG.
Gold can't be bad, right? As it turns out, even gold coin has two sides to it.
I have found that Shlepnev and McMorrow conducted extensive research and published data, some of which is presented here http://www.simberian.com/Presentations/NickelCharacterizationPresentation_emc2011.pdf
the ever useful http://www.microwaves101.com/ site has an excellent
discussion of this under the "skin effect" heading.
Hi
The same nickel plating effect gets into a lot of things. If you are shopping for very
low IMD connectors, nickel plating is out. Things get non-linear (to a very slight
degree) when it is present. If -180 db is the goal for those spurs, you might only
hit -120 db with the nickel connectors …..
Bob
On Feb 22, 2018, at 9:15 PM, jimlux jimlux@earthlink.net wrote:
On 2/22/18 12:29 PM, Leo Bodnar wrote:
Here is ENIG fact that is not widely known at the moment but which some might find useful.
I could not understand why I get better TDR and insertion loss results from solder-mask covered microstrip transmission lines than from otherwise identical microstrips on the same substrate with soldermask removed and, therefore, covered with ENIG.
Gold can't be bad, right? As it turns out, even gold coin has two sides to it.
I have found that Shlepnev and McMorrow conducted extensive research and published data, some of which is presented here http://www.simberian.com/Presentations/NickelCharacterizationPresentation_emc2011.pdf
the ever useful http://www.microwaves101.com/ site has an excellent discussion of this under the "skin effect" heading.
time-nuts mailing list -- time-nuts@febo.com
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and follow the instructions there.
Keep in mind that soldermask will also change the field distributions
around a
microstrip line, and will somewhat mitigate the microstrip's dispersive
behavior
as well.
I once worked with some miccrostrip couplers at around 2-4 GHz and found
that
directivity was significantly improved by adding two layers of thin kapton
tape
on top of the coupled region, a solution that went into production. I
expect that
the usual soldermask layer would have about the same effect.
Dana
On Thu, Feb 22, 2018 at 8:15 PM, jimlux jimlux@earthlink.net wrote:
On 2/22/18 12:29 PM, Leo Bodnar wrote:
Here is ENIG fact that is not widely known at the moment but which some
might find useful.
I could not understand why I get better TDR and insertion loss results
from solder-mask covered microstrip transmission lines than from otherwise
identical microstrips on the same substrate with soldermask removed and,
therefore, covered with ENIG.
Gold can't be bad, right? As it turns out, even gold coin has two sides
to it.
I have found that Shlepnev and McMorrow conducted extensive research and
published data, some of which is presented here
http://www.simberian.com/Presentations/NickelCharacterizatio
nPresentation_emc2011.pdf
the ever useful http://www.microwaves101.com/ site has an excellent
discussion of this under the "skin effect" heading.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/m
ailman/listinfo/time-nuts
and follow the instructions there.
Hoi Bob,
On Thu, 22 Feb 2018 21:58:09 -0500
Bob kb8tq kb8tq@n1k.org wrote:
The same nickel plating effect gets into a lot of things. If you are shopping for very
low IMD connectors, nickel plating is out. Things get non-linear (to a very slight
degree) when it is present. If -180 db is the goal for those spurs, you might only
hit -120 db with the nickel connectors …..
Interesting. About what frequency range are you talking?
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Matheson, The Diamond Age, Neil Stephenson
Hi
On Feb 23, 2018, at 4:23 PM, Attila Kinali attila@kinali.ch wrote:
Hoi Bob,
On Thu, 22 Feb 2018 21:58:09 -0500
Bob kb8tq kb8tq@n1k.org wrote:
The same nickel plating effect gets into a lot of things. If you are shopping for very
low IMD connectors, nickel plating is out. Things get non-linear (to a very slight
degree) when it is present. If -180 db is the goal for those spurs, you might only
hit -120 db with the nickel connectors …..
Interesting. About what frequency range are you talking?
UHF up into microwaves. It was part of a lecture back when I was in school … I
assume the basic physics hasn’t changed since then :)
Bob
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Matheson, The Diamond Age, Neil Stephenson
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
On Thu, Feb 22, 2018 at 3:29 PM, Leo Bodnar leo@leobodnar.com wrote:
Here is ENIG fact that is not widely known at the moment but which some might find useful.
I could not understand why I get better TDR and insertion loss results from solder-mask covered microstrip transmission lines than from otherwise identical microstrips on the same substrate with soldermask removed and, therefore, covered with ENIG.
Gold can't be bad, right? As it turns out, even gold coin has two sides to it.
I have found that Shlepnev and McMorrow conducted extensive research and published data, some of which is presented here http://www.simberian.com/Presentations/NickelCharacterizationPresentation_emc2011.pdf
In essence, it's not the "G" that is the problem - it is the "N".
Immersion Gold layer is not thick enough to contain whole of the skin effect layer (even towards 100GHz) and as signal frequency increases most of the signal ends up travelling through Nickel.
As Shlepnev commented "Nickel is the most mysterious metal in electronics." It has significant effect on insertion loss and risetime degradation. "Significant effect" is posh for "bad."
It might be the most mysterious, but Zinc gets my vote for "most
annoying". See:
https://nepp.nasa.gov/whisker/reference/tech_papers/2004-Brusse-Zn-whisker-IT-Pro.pdf
I once worked in a datacenter which had such a bad case of zinc
whiskers that, when we got bored, we'd turn off the lights and watch
the pretty blue arcs as the whiskers would get pulled through power
supplies, bridge something which could deliver current and vaporize,
making a small snapping noise in the process. The scary part was that
you could bang on the side of a crac, wait 30 seconds, and be rewarded
with a fireworks show...
W
Some mass PCB manufacturers have been known to apply ENIG before soldermasking. This causes even more high speed/frequency problems because all of the copper on the outside layers will have Nickel over it - exposed or not.
Probably not a problem for majority of ENIG users but could cause a headache or two for unsuspecting.
Leo
Date: Thu, 22 Feb 2018 19:02:25 +0000
From: Mark Sims holrum@hotmail.com
Yes, have the board done with ENIG gold. It typically adds around $15 per run of boards. I do all my boards with ENIG gold... if for no other reason than the gold color makes it very easy to determine when your solder paste properly covers the pads.
And, as Charles mentioned, the quality and thickness of the gold can vary depending upon the board house. I have used gojgo.com for a lot of boards. They do very good, quick work, are well priced, and they seem to have the best gold finish.
Hard gold finish is VERY expensive these days. I've been quoted $250+ for setup charges and per-board costs of over $25.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
--
I don't think the execution is relevant when it was obviously a bad
idea in the first place.
This is like putting rabid weasels in your pants, and later expressing
regret at having chosen those particular rabid weasels and that pair
of pants.
---maf