Solder to Aluminum?

C

Chris Carlen

Guest
Hi:

I have voice coils wound with aluminum magnet wire that I need to solder
to a flex-PCB with tin plated pads.

Any idea on the best alloy/flux combo for that? Low melting temperature
possible would be best to avoid harming the polyimide PCB substrate.


Thanks.


--
_______________________________________________________________________
Christopher R. Carlen
Principal Laser/Optical Technologist
Sandia National Laboratories CA USA
crcarleRemoveThis@BOGUSsandia.gov
NOTE, delete texts: "RemoveThis" and "BOGUS" from email address to reply.
 
In article <d8n8kf02gd4@news3.newsguy.com>,
Chris Carlen <crcarleRemoveThis@BOGUSsandia.gov> wrote:

Hi:

I have voice coils wound with aluminum magnet wire that I need to solder
to a flex-PCB with tin plated pads.

Any idea on the best alloy/flux combo for that? Low melting temperature
possible would be best to avoid harming the polyimide PCB substrate.


Thanks.
Click to expand...
Spot weld the aluminum wire to copper wire. If you don't want to spot
weld, then use crimp hardware designed for aluminum/copper connections.
Then solder the copper wire to whatever.

Al
 
Chris Carlen wrote:
Hi:

I have voice coils wound with aluminum magnet wire that I need to solder
to a flex-PCB with tin plated pads.

Any idea on the best alloy/flux combo for that? Low melting temperature
possible would be best to avoid harming the polyimide PCB substrate.


Thanks.
Click to expand...
Depends somewhat on the size of your wire.
There are various fluxes containing fluorides that can work on aluminum.

There's some stuff called "solder-it" or "Kool-it brand" made by
universal corporation. They have a lot of specialty soldering stuff.

There's some aluminum welding rod called Welco 52. Can get it at any
welding supply house. Made for low temperature welding of aluminum
pieces. Also sold in hardware stores
as no-flux aluminum solder or brazing rod.

If your wire is big enough, you can use the Welco 52 and a torch to
"tin" the wire. Then you can solder to the Welco 52 coating. I've used
that technique to make aluminum resonant cavities that I could assemble
with ordinary solder.

Voice coil implies motion. Aluminum doesn't flex well. Make sure
the aluminum part stays rigid.
mike

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"Al" <no.spam@wanted.com> wrote in message
news:no.spam-137615.15214914062005@news.verizon.net...
In article <d8n8kf02gd4@news3.newsguy.com>,
Chris Carlen <crcarleRemoveThis@BOGUSsandia.gov> wrote:

Hi:

I have voice coils wound with aluminum magnet wire that I need to solder
to a flex-PCB with tin plated pads.

Any idea on the best alloy/flux combo for that? Low melting temperature
possible would be best to avoid harming the polyimide PCB substrate.


Thanks.

Spot weld the aluminum wire to copper wire. If you don't want to spot
weld, then use crimp hardware designed for aluminum/copper connections.
Then solder the copper wire to whatever.

Al
Click to expand...
cant say if this is suitable or not, but the soldering iron tip
wetter/flux/solder paste has an extremly active flux, ive used it to solder
nichrome wire onto a pcb before, i did have some aluminium solder too but
dont think i had much luck with it.

Colin =^.^=
 
"Chris Carlen" <crcarleRemoveThis@BOGUSsandia.gov> wrote in message
news:d8n8kf02gd4@news3.newsguy.com...
Hi:

I have voice coils wound with aluminum magnet wire that I need to solder
to a flex-PCB with tin plated pads.

Any idea on the best alloy/flux combo for that? Low melting temperature
possible would be best to avoid harming the polyimide PCB substrate.


Thanks.
I'd say 'forget it'. There are solders that will join aluminium to copper,
Click to expand...
but most involve an intermediate alloy, and some fairly nasty fluxes, and
are usually at the higher temperature end of normal soft soldering
temperatures. Have a look at:
www.tra-con.com and look at Tra-Duct 2902. This could be ideal for the
application.

Best Wishes
 
Al wrote:
In article <d8n8kf02gd4@news3.newsguy.com>,
Chris Carlen <crcarleRemoveThis@BOGUSsandia.gov> wrote:

Hi:

I have voice coils wound with aluminum magnet wire that I need to solder
to a flex-PCB with tin plated pads.

Any idea on the best alloy/flux combo for that? Low melting temperature
possible would be best to avoid harming the polyimide PCB substrate.


Thanks.

Spot weld the aluminum wire to copper wire. If you don't want to spot
weld, then use crimp hardware designed for aluminum/copper connections.
Then solder the copper wire to whatever.
Click to expand...

That would be a nice way to do things, if there was enough space. But
the coil terminations are about 4mm long, recessed in a notch in the
aluminum coil former. I have existing coils that I wish to rebuild,
that were soldered, so I know it can be done.


Thanks for the input.

Good day!



--
_______________________________________________________________________
Christopher R. Carlen
Principal Laser/Optical Technologist
Sandia National Laboratories CA USA
crcarleRemoveThis@BOGUSsandia.gov
NOTE, delete texts: "RemoveThis" and "BOGUS" from email address to reply.
 
"Roger Hamlett" <rogerspamignored@ttelmah.demon.co.uk> wrote in message
news:YSGre.13111$a5.7854@newsfe5-win.ntli.net...
"Chris Carlen" <crcarleRemoveThis@BOGUSsandia.gov> wrote in message
news:d8n8kf02gd4@news3.newsguy.com...
Hi:

I have voice coils wound with aluminum magnet wire that I need to solder
to a flex-PCB with tin plated pads.

Any idea on the best alloy/flux combo for that? Low melting temperature
possible would be best to avoid harming the polyimide PCB substrate.


Thanks.
I'd say 'forget it'. There are solders that will join aluminium to copper,
but most involve an intermediate alloy, and some fairly nasty fluxes, and
are usually at the higher temperature end of normal soft soldering
temperatures. Have a look at:
www.tra-con.com and look at Tra-Duct 2902. This could be ideal for the
application.

Best Wishes
Click to expand...
There are quite a few metal filled epoxies around. Some with quite low
resistance (the silver impregnated ones). Check the industry for those and
then there's always:

http://jbweld.net/products/jbweld.php

Robert
 
Robert wrote:

"Roger Hamlett" <rogerspamignored@ttelmah.demon.co.uk> wrote in message
news:YSGre.13111$a5.7854@newsfe5-win.ntli.net...

"Chris Carlen" <crcarleRemoveThis@BOGUSsandia.gov> wrote in message
news:d8n8kf02gd4@news3.newsguy.com...

Hi:

I have voice coils wound with aluminum magnet wire that I need to solder
to a flex-PCB with tin plated pads.

Any idea on the best alloy/flux combo for that? Low melting temperature
possible would be best to avoid harming the polyimide PCB substrate.


Thanks.

I'd say 'forget it'. There are solders that will join aluminium to copper,
but most involve an intermediate alloy, and some fairly nasty fluxes, and
are usually at the higher temperature end of normal soft soldering
temperatures. Have a look at:
www.tra-con.com and look at Tra-Duct 2902. This could be ideal for the
application.

Best Wishes


There are quite a few metal filled epoxies around. Some with quite low
resistance (the silver impregnated ones). Check the industry for those and
then there's always:

http://jbweld.net/products/jbweld.php

Robert


JB Weld is excellent to hold things together.
Click to expand...
BUT.
It is a darn good *insulator*.
 
Chris Carlen wrote:

Hi:

I have voice coils wound with aluminum magnet wire that I need to solder
to a flex-PCB with tin plated pads.

Any idea on the best alloy/flux combo for that? Low melting temperature
possible would be best to avoid harming the polyimide PCB substrate.


Thanks.


Over 40 years ago, i wanted to solder to aluminum, and so bought some
Click to expand...
special solder for that, useable with ordinary solder irons.
A bit problematic, as it had chromium (if i remember correctly), and
the fumes were toxic.
Worked *very* well; in fact, too well if the aluminum was too thin;
the alloy crept underneath the oxide skin and leached the aluminum,
making it thinner if one was not careful.
The basic secret to soldering aluminim, is getting underneath or thru
the oxide skin without allowing the aluminum to protect itself by
creating new oxide.
One can use ordinary electronic solder, and a rather active flux to
break down the oxide and cover the area from oxygen.
Once there is a break, the solder will *very* easily flow underneath
the skin (makes it bulge as the solder flows underneath).
The solder will quickly flow over the are wheer it is hot enough to
keep it a liquid.
So if you can heat a local are just enough to get that break, and
quickly wipe the oxide off as it cools, then one can later do a quick
solder of a copper wire to that area.
Practice a lot on first a 1/16th inch sheet and then on similarly
sized wires before doing the real thing!
 
Chris Carlen wrote:
Hi:

I have voice coils wound with aluminum magnet wire that I need to solder
to a flex-PCB with tin plated pads.

Any idea on the best alloy/flux combo for that? Low melting temperature
possible would be best to avoid harming the polyimide PCB substrate.
Click to expand...
Well, I use Alusol from Multicore. It is listed for example at http://www.elfa.se/en/
(search for Alusol). Melting point may be rather high perhaps - and the website says not suitable for electrical joints - but
it works for me.
 
Solder in an inert atmosphere/vacuum, maybe?

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Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433
 
On Wed, 15 Jun 2005 02:38:24 +0000, David Lesher wrote:

Solder in an inert atmosphere/vacuum, maybe?]
Click to expand...
You are on the right track: don't let the Al2O3 reform.
Instead of vacuum/inert gas, I had good luck with soldering under
a droplet of engine oil. I was soldering to a 1mm by 1 cm Al strip, using
a small 30 W iron; I wetted the tip with a blob of solder, and touched the
side of the oil droplet, while scrapping the area covered by oil with a
dental pick. Within 10-20 seconds, the solder wetted the scratched area
under the oil.
 
David Lesher wrote:
Solder in an inert atmosphere/vacuum, maybe?

No need for that extreme; most liquid fluxes stay around and keep the
Click to expand...
oxygen out.
 
przemek klosowski wrote:

On Wed, 15 Jun 2005 02:38:24 +0000, David Lesher wrote:



Solder in an inert atmosphere/vacuum, maybe?]


You are on the right track: don't let the Al2O3 reform.
Instead of vacuum/inert gas, I had good luck with soldering under
a droplet of engine oil. I was soldering to a 1mm by 1 cm Al strip, using
a small 30 W iron; I wetted the tip with a blob of solder, and touched the
side of the oil droplet, while scrapping the area covered by oil with a
dental pick. Within 10-20 seconds, the solder wetted the scratched area
under the oil.
OIL! Did not think of that.
Click to expand...
Forgive the pun, but that was a slick idea!
 
richard mullens wrote:
Chris Carlen wrote:
Hi:

I have voice coils wound with aluminum magnet wire that I need to
solder to a flex-PCB with tin plated pads.

Any idea on the best alloy/flux combo for that? Low melting
temperature possible would be best to avoid harming the polyimide PCB
substrate.


Well, I use Alusol from Multicore. It is listed for example at
http://www.elfa.se/en/
(search for Alusol). Melting point may be rather high perhaps - and the
website says not suitable for electrical joints - but it works for me.
Click to expand...


There is an alloy from Indium Corp that is 91Sn 9Zn which can solder Al
with a flux. I'm waiting for them to get back to me.

I can't find a US distributor of that Alusol anywhere. Thanks for the
link, though.

Good day!




--
_______________________________________________________________________
Christopher R. Carlen
Principal Laser/Optical Technologist
Sandia National Laboratories CA USA
crcarleRemoveThis@BOGUSsandia.gov
NOTE, delete texts: "RemoveThis" and "BOGUS" from email address to reply.
 
The technique I've read for soldering to aluminum with zinc alloys is to
melt a blob of solder onto the aluminum and then to keep scratching back
and forth at the bottom of the puddle with the soldering iron tip. This
scratches through the aluminum oxide layer and exposes fresh aluminum
which the solder bonds to, while the puddle of solder itself keeps
oxygen away.

--
Regards,
Carl Ijames carl.ijames at verizon.net
 
On Wed, 15 Jun 2005 23:51:12 GMT, "Carl Ijames"
<carl.ijames@nospm.verizon.net> wrote:

The technique I've read for soldering to aluminum with zinc alloys is to
melt a blob of solder onto the aluminum and then to keep scratching back
and forth at the bottom of the puddle with the soldering iron tip. This
scratches through the aluminum oxide layer and exposes fresh aluminum
which the solder bonds to, while the puddle of solder itself keeps
oxygen away.
Click to expand...
I haven't done it in years, but I recall a block of some substance
with which you abraded the surface of the aluminum and then you could
solder to it in a normal fashion.

...Jim Thompson
--
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| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
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I love to cook with wine. Sometimes I even put it in the food.
 
In article <ktf1b1luoitgt5uq46ombgebqglvmquema@4ax.com>,
Jim Thompson <thegreatone@example.com> wrote:

On Wed, 15 Jun 2005 23:51:12 GMT, "Carl Ijames"
carl.ijames@nospm.verizon.net> wrote:

The technique I've read for soldering to aluminum with zinc alloys is to
melt a blob of solder onto the aluminum and then to keep scratching back
and forth at the bottom of the puddle with the soldering iron tip. This
scratches through the aluminum oxide layer and exposes fresh aluminum
which the solder bonds to, while the puddle of solder itself keeps
oxygen away.

I haven't done it in years, but I recall a block of some substance
with which you abraded the surface of the aluminum and then you could
solder to it in a normal fashion.

...Jim Thompson
Click to expand...
Might be sal ammoniac also known as ammonium chloride. You used to be
able to buy them at Sears many moons ago.

Al
 
"Al" <no.spam@wanted.com> wrote in message
news:no.spam-0F3AA3.08521116062005@news.verizon.net...
In article <ktf1b1luoitgt5uq46ombgebqglvmquema@4ax.com>,
Jim Thompson <thegreatone@example.com> wrote:

On Wed, 15 Jun 2005 23:51:12 GMT, "Carl Ijames"
carl.ijames@nospm.verizon.net> wrote:

The technique I've read for soldering to aluminum with zinc alloys is to
melt a blob of solder onto the aluminum and then to keep scratching back
and forth at the bottom of the puddle with the soldering iron tip. This
scratches through the aluminum oxide layer and exposes fresh aluminum
which the solder bonds to, while the puddle of solder itself keeps
oxygen away.

I haven't done it in years, but I recall a block of some substance
with which you abraded the surface of the aluminum and then you could
solder to it in a normal fashion.

...Jim Thompson

Might be sal ammoniac also known as ammonium chloride. You used to be
able to buy them at Sears many moons ago.

Al
Here is something most folk don't know. During WWII the RAF mechanics used
Click to expand...
to solder plates over the bullet holes in Spitfire engines. They used a
really hot iron and heavy engine oil. As an experiment I had a go at
soldering aluminium and their method worked but was a bit hit or miss. You
have to solder through a film of engine oil and keep the iron vigorously
moving while tinning the surfaces. Yeah! I know it is not what you wanted
but it was just a bit of history.
--

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Robert, (Auld Bob), Peffers,
Kelty,
Fife,
Scotland, (UK).
Web Site, "The Eck's Files":- http://www.peffers50.freeserve.co.uk
 
Robert Peffers wrote:

[...]

Here is something most folk don't know. During WWII the RAF mechanics used
to solder plates over the bullet holes in Spitfire engines. They used a
really hot iron and heavy engine oil. As an experiment I had a go at
soldering aluminium and their method worked but was a bit hit or miss. You
have to solder through a film of engine oil and keep the iron vigorously
moving while tinning the surfaces. Yeah! I know it is not what you wanted
but it was just a bit of history.
Click to expand...
You'd think a bullet hole would mean a ruined engine and a crashed plane.

Where and how can you put a hole in an engine without destroying it?

Mike Monett
 
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