low emf solder
Found reference to optimal emf solder composition cadmium/tin alloy
(70 %/30 %) in JJ array measurement article page 12.
www.bipm.org/utils/common/pdf/rapportBIPM/2011/05.pdf
Quick look at ebay show 1/4 kg of pure cadmium cost 10$ (item 111333082639),
so you can make quite a lot of solder for cheap ...
Also interesting way to thermally anchor interconnection leads to
copper block in page 11.
J.
I would recommend against trying to use cadmium - it's very toxic, which
is why Cd-based solders are rare nowadays. They are probably still made,
but for lab or industrial use with proper handling. If you try to alloy
it with Sn yourself without proper handling, you could get poisoned. You
can't just throw the ingredients in a solder pot and expect good results.
Ed
Let's don't get carried away with cadmium toxicity. Yes, it is toxic is
sufficient dose but the LD50 dose for Cd is 750 mg/kg while the value
for lead is around 450mg/kg.
As far as dumping it in a solder pot, that works just fine for me. It's
cheaper to buy 50/50 plumber's bar solder and then add the appropriate
amount of lead to get to the eutectic point.
One should also realize that cad-plated hardware is still available. I
get mine from McMaster-Carr.
John
On 10/28/2016 12:39 PM, ed breya wrote:
I would recommend against trying to use cadmium - it's very toxic, which
is why Cd-based solders are rare nowadays. They are probably still made,
but for lab or industrial use with proper handling. If you try to alloy
it with Sn yourself without proper handling, you could get poisoned. You
can't just throw the ingredients in a solder pot and expect good results.
Ed
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Tellico Plains, Occupied TN
http://www.tnduction.com <-- THE source for induction heaters
http://www.neon-john.com <-- email from here
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LD50 is not the only consideration. From Wikipedia:
"The International Agency for Research on Cancer has classified cadmium and cadmium compounds as carcinogenic to humans."
FWIW
Neville Michie
On 29 Oct 2016, at 8:09 AM, NeonJohn jgd@neon-john.com wrote:
Let's don't get carried away with cadmium toxicity. Yes, it is toxic is
sufficient dose but the LD50 dose for Cd is 750 mg/kg while the value
for lead is around 450mg/kg.
As far as dumping it in a solder pot, that works just fine for me. It's
cheaper to buy 50/50 plumber's bar solder and then add the appropriate
amount of lead to get to the eutectic point.
One should also realize that cad-plated hardware is still available. I
get mine from McMaster-Carr.
John
On 10/28/2016 12:39 PM, ed breya wrote:
I would recommend against trying to use cadmium - it's very toxic, which
is why Cd-based solders are rare nowadays. They are probably still made,
but for lab or industrial use with proper handling. If you try to alloy
it with Sn yourself without proper handling, you could get poisoned. You
can't just throw the ingredients in a solder pot and expect good results.
Ed
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--
John DeArmond
Tellico Plains, Occupied TN
http://www.tnduction.com <-- THE source for induction heaters
http://www.neon-john.com <-- email from here
http://www.johndearmond.com <-- Best damned Blog on the net
PGP key: wwwkeys.pgp.net: BCB68D77
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In message c4a50a25-5082-c8ba-b225-fce103a5c774@neon-john.com, NeonJohn writes:
Let's don't get carried away with cadmium toxicity. Yes, it is toxic is
sufficient dose but the LD50 dose for Cd is 750 mg/kg while the value
for lead is around 450mg/kg.
Read how a professional chemist describes cadmium:
http://blogs.sciencemag.org/pipeline/archives/2013/05/08/things_i_wont_work_with_dimethylcadmium
--
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phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
On 28 Oct 2016 15:25, "Juris L" juris.l@gmail.com wrote:
Found reference to optimal emf solder composition cadmium/tin alloy
(70 %/30 %) in JJ array measurement article page 12.
I wonder how practical it is to weld test leads, so there's no solder or
thermal EMF.
I know that this will sound crazy, and probably is, but could one weld
components to a PCB?
I don't even have the excuse of been drunk or taking drugs, but I will
risk ridicule for making the above comment! Sometimes thinking out of the
box is useful.
Dave.
Laser welding should work for either similar or dissimilar materials.At one time microwire PCBs used stainless steel wires were welded to stainless lands.
Bruce
On Saturday, 29 October 2016 1:39 PM, Dr. David Kirkby (Kirkby Microwave Ltd) <drkirkby@kirkbymicrowave.co.uk> wrote:
On 28 Oct 2016 15:25, "Juris L" juris.l@gmail.com wrote:
Found reference to optimal emf solder composition cadmium/tin alloy
(70 %/30 %) in JJ array measurement article page 12.
I wonder how practical it is to weld test leads, so there's no solder or
thermal EMF.
I know that this will sound crazy, and probably is, but could one weld
components to a PCB?
I don't even have the excuse of been drunk or taking drugs, but I will
risk ridicule for making the above comment! Sometimes thinking out of the
box is useful.
Dave.
volt-nuts mailing list -- volt-nuts@febo.com
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and follow the instructions there.
I note that I weld thermocouples.
hld
Howard L. Davidson
hld42@att.net
From: Dr. David Kirkby (Kirkby Microwave Ltd) <drkirkby@kirkbymicrowave.co.uk>
To: Discussion of precise voltage measurement volt-nuts@febo.com
Sent: Friday, October 28, 2016 5:39 PM
Subject: Re: [volt-nuts] low emf solder
On 28 Oct 2016 15:25, "Juris L" juris.l@gmail.com wrote:
Found reference to optimal emf solder composition cadmium/tin alloy
(70 %/30 %) in JJ array measurement article page 12.
I wonder how practical it is to weld test leads, so there's no solder or
thermal EMF.
I know that this will sound crazy, and probably is, but could one weld
components to a PCB?
I don't even have the excuse of been drunk or taking drugs, but I will
risk ridicule for making the above comment! Sometimes thinking out of the
box is useful.
Dave.
volt-nuts mailing list -- volt-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.
"chip on board", not sure that it wouldnt help
On Friday, 28 October 2016, Dr. David Kirkby (Kirkby Microwave Ltd) <
drkirkby@kirkbymicrowave.co.uk> wrote:
On 28 Oct 2016 15:25, "Juris L" <juris.l@gmail.com javascript:;> wrote:
Found reference to optimal emf solder composition cadmium/tin alloy
(70 %/30 %) in JJ array measurement article page 12.
I wonder how practical it is to weld test leads, so there's no solder or
thermal EMF.
I know that this will sound crazy, and probably is, but could one weld
components to a PCB?
I don't even have the excuse of been drunk or taking drugs, but I will
risk ridicule for making the above comment! Sometimes thinking out of the
box is useful.
Dave.
volt-nuts mailing list -- volt-nuts@febo.com javascript:;
To unsubscribe, go to https://www.febo.com/cgi-bin/
mailman/listinfo/volt-nuts
and follow the instructions there.
Typing on phone... If the bond wires are gold they still are dissimilar to
pcb copper, but if they were copper bond wires, thermal gradients would be
less of an issue.
On Friday, 28 October 2016, Scott Stobbe scott.j.stobbe@gmail.com wrote:
"chip on board", not sure that it wouldnt help
On Friday, 28 October 2016, Dr. David Kirkby (Kirkby Microwave Ltd) <
drkirkby@kirkbymicrowave.co.uk
javascript:_e(%7B%7D,'cvml','drkirkby@kirkbymicrowave.co.uk');> wrote:
On 28 Oct 2016 15:25, "Juris L" juris.l@gmail.com wrote:
Found reference to optimal emf solder composition cadmium/tin alloy
(70 %/30 %) in JJ array measurement article page 12.
I wonder how practical it is to weld test leads, so there's no solder or
thermal EMF.
I know that this will sound crazy, and probably is, but could one weld
components to a PCB?
I don't even have the excuse of been drunk or taking drugs, but I will
risk ridicule for making the above comment! Sometimes thinking out of the
box is useful.
Dave.
volt-nuts mailing list -- volt-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/m
ailman/listinfo/volt-nuts
and follow the instructions there.