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Soldering SMT Components

I'm looking for Do-it Yourselft articles on soldering surface mount
components. I can't afford the IR equipment that commercial board
houses use. I'm particularly interested in soldering the new ROHS
components that require lead free solder. The lead free solders
require higher temperatures. Also, do board coatings prevent problems
with tin whiskers that grow from the lead free solders?
 
R

Rich Webb

Jan 1, 1970
0
It's easy to solder most surface-mount parts by hand; just practise a
bit.

[Sure is handy to have somebody else pre-filter the googlegroupers
that are whitelist-able. Thanks, John! ;-) ]

And for the OP ... there are scads of how-to pages out there. The
tutorials at <http://www.sparkfun.com/commerce/hdr.php?p=tutorials>
(scroll way down for the surface mount stuff) have pretty good info
for the enthusiast/hobbyist, including video clips.
 
L

Leon

Jan 1, 1970
0
I'm looking for Do-it Yourselft articles on soldering surface mount
components. I can't afford the IR equipment that commercial board
houses use. I'm particularly interested in soldering the new ROHS
components that require lead free solder. The lead free solders
require higher temperatures. Also, do board coatings prevent problems
with tin whiskers that grow from the lead free solders?

I do surface mount assembly with an ordinary Metcal soldering station.
I solder Rs and Cs using a small tip cartridge, and fine-pitch devices
by drag-soldering with a mini-hoof cartridge.

Leon
 
M

Martin Griffith

Jan 1, 1970
0
On Mon, 14 Apr 2008 11:49:27 -0700 (PDT), [email protected] wrote:

I'm looking for Do-it Yourselft articles on soldering surface mount
components. I can't afford the IR equipment that commercial board
houses use. I'm particularly interested in soldering the new ROHS
components that require lead free solder. The lead free solders
require higher temperatures. Also, do board coatings prevent problems
with tin whiskers that grow from the lead free solders?

It's easy to solder most surface-mount parts by hand; just practise a
bit.

[Sure is handy to have somebody else pre-filter the googlegroupers
that are whitelist-able. Thanks, John! ;-) ]

And for the OP ... there are scads of how-to pages out there. The
tutorials at <http://www.sparkfun.com/commerce/hdr.php?p=tutorials>
(scroll way down for the surface mount stuff) have pretty good info
for the enthusiast/hobbyist, including video clips.

There are even people doing BGAs in toaster ovens.

We used to send our BGAs out to assembly houses, out of pure fear.
Then we tried some in-house. We bought a bunch of inspection and
rework gear, which we've mostly never used. Our yield so far is
100.0%.

John
Lead free toast, yum


martin
 
J

Joerg

Jan 1, 1970
0
Leon said:
I do surface mount assembly with an ordinary Metcal soldering station.
I solder Rs and Cs using a small tip cartridge, and fine-pitch devices
by drag-soldering with a mini-hoof cartridge.

Metcal, ordinary? Those are the Mercedes-Benzes of solder stations. They
are great but the ones I have used at clients were well north of $500.
 
G

Glen Walpert

Jan 1, 1970
0
Tin whiskers do not grow from lead-free solders, where did you get
that crazy idea? Tin whiskers grow from tin plating and only tin
plating.
It's easy to solder most surface-mount parts by hand; just practise a
bit.

And it's OK to use rosin-flux leaded (63/37) solder, even to solder
lead-free parts. Better in fact.

As far as I know, nothing prevents whiskers, not even coatings. Except
lead, of course.

Lead does not prevent tin whiskers any better than any other means of
pinning dislocations in tin, such as any of the alloys used as
lead-free solders. No one has ever been able to show me believable
evidence that so much as a single tin whisker has ever grown from any
currently used lead-free solder alloy, and I doubt they ever will, it
is simply not a valid reliability issue.

Complaining about problems with lead-free these days makes as much
sense as still worrying about the Y2K bug. Forget about it, the
conversion is over and done with for all but the smallest
manufacturers, and reliability of the assembled circuits has continued
to increase.

Lead is in fact not a very good means of preventing tin whiskers, due
to well know problem of poor fatigue strength of tin-lead solders.
All high-rel applications which need to withstand shock and vibration
will be converting to lead-free; not the lowest cost SAC alloy but
high performance lead-free alloys which are now being qualified (a
lengthy process) but which clearly blow the socks off tin-lead in
strength, ductility, shock resistance and fatigue life; all of the
properties important for reliability except processing temperature are
greatly improved and the processing temp for these alloys is only
slightly higher than tin-lead. See for instance:
<http://smt.pennnet.com/display_arti...one/1/STEP-3:-Holistic-Lead-free-Reliability/>

The down sides to lead-free are slightly higher cost and far higher
complexity of specifying the optimum alloy, flux, and processing
parameters, plus a need for tighter process controls.

This is not a reasonable forum for learning about soldering or PCB
assembly in general, the issue is too complex and almost no one here
is interested in it enough to have read up on the subject. Read the
trade rags like SMT <http://smt.pennnet.com/home.cfm> and Printed
Circuit Design and Fab <http://www.pcdandf.com/cms/> for a decent
introduction to the subject.
 
T

T

Jan 1, 1970
0
It's easy to solder most surface-mount parts by hand; just practise a
bit.

[Sure is handy to have somebody else pre-filter the googlegroupers
that are whitelist-able. Thanks, John! ;-) ]

And for the OP ... there are scads of how-to pages out there. The
tutorials at <http://www.sparkfun.com/commerce/hdr.php?p=tutorials>
(scroll way down for the surface mount stuff) have pretty good info
for the enthusiast/hobbyist, including video clips.

The easiest way I've found to do SMT is drop a little bit of solder on
the pads, then lay part on top and touch iron to the lead from the part
and let it melt the solder.

I imagine with lead free this might not work so well but it works fine
with rosin core.
 
S

sprocket

Jan 1, 1970
0
Leon said:
I do surface mount assembly with an ordinary Metcal soldering station.
I solder Rs and Cs using a small tip cartridge, and fine-pitch devices
by drag-soldering with a mini-hoof cartridge.

I've given up on these posh tips for fine-pitch. My ancient Weller with
a 2mm tip works as well once you've got the knack. Occasional cleanup
with solderwick afterwards, but the posh ones sometimes need that too.
 
Q

qrk

Jan 1, 1970
0
Metcal, ordinary? Those are the Mercedes-Benzes of solder stations. They
are great but the ones I have used at clients were well north of $500.

Metcal has a cheap iron for about $180 (PS-800). Tips are about $8 or
$9. I use the 650 deg 0.016" tips for most of my work (0402 size and
0.5mm pitch parts). I like the small footprint of the station.
http://www.hmcelectronics.com/cgi-bin/scripts/product/5635-0199/ has
pretty good pricing.

For soldering those pesky ICs with the heat slug under the part, I use
a waffle iron. The waffle iron I have has dual purpose plates, one
side for making waffles, the other side is flat for, I'm guessing,
grilled cheese and soldering.
 
L

Leon

Jan 1, 1970
0
Metcal, ordinary? Those are the Mercedes-Benzes of solder stations. They
are great but the ones I have used at clients were well north of $500.

I got one of the older STSS power units cheap on Ebay. It can
be used with the current MX-500 handpieces and cartridges.

The whole system cost me about 120 GBP, less than a new Weller system.

Leon
 
J

Joerg

Jan 1, 1970
0
qrk said:
Metcal has a cheap iron for about $180 (PS-800). Tips are about $8 or
$9. I use the 650 deg 0.016" tips for most of my work (0402 size and
0.5mm pitch parts). I like the small footprint of the station.
http://www.hmcelectronics.com/cgi-bin/scripts/product/5635-0199/ has
pretty good pricing.

Thanks! That seems like a good place to buy tools. They've got good
pricing on Hakko as well. So I bookmarked them. But I can't use a fixed
temperature iron here in the lab because as a consultant I have to deal
with widely different technology.

For soldering those pesky ICs with the heat slug under the part, I use
a waffle iron. The waffle iron I have has dual purpose plates, one
side for making waffles, the other side is flat for, I'm guessing,
grilled cheese and soldering.

My wife would not approve and I might not get waffles anymore ;-)
 
J

Joerg

Jan 1, 1970
0
Leon said:
I got one of the older STSS power units cheap on Ebay. It can
be used with the current MX-500 handpieces and cartridges.

The whole system cost me about 120 GBP, less than a new Weller system.

It's weird, I looked and indeed, Farnell charges you guys an arm and a
leg. It was the same when I bought a new scope. Came from Farnell-UK
(with a UK power cord!) yet cost me a whole lot less via Newark. Same
for irons:

http://www.newark.com/92C1414/tools-production-supplies/product.us0?sku=COOPER-TOOLS-WELLER-WES51

$127 for a WES51 station is a darn good deal. Maybe it's the RoHS
compliance why they have you guys over the barrel.
 
J

John Devereux

Jan 1, 1970
0
qrk said:
Metcal has a cheap iron for about $180 (PS-800). Tips are about $8 or
$9. I use the 650 deg 0.016" tips for most of my work (0402 size and
0.5mm pitch parts). I like the small footprint of the station.
http://www.hmcelectronics.com/cgi-bin/scripts/product/5635-0199/ has
pretty good pricing.

For soldering those pesky ICs with the heat slug under the part, I use
a waffle iron. The waffle iron I have has dual purpose plates, one
side for making waffles, the other side is flat for, I'm guessing,
grilled cheese and soldering.

You Americans(?) are so lucky... here in the UK we have none of these
"toaster ovens" or "waffle irons" which seem to be so essential for
the serious constructor.

I mean, how can we be expected to do serious electronics without the
correct tools for the job?
 
L

Leon

Jan 1, 1970
0
You Americans(?) are so lucky... here in the UK we have none of these
"toaster ovens" or "waffle irons" which seem to be so essential for
the serious constructor.

I mean, how can we be expected to do serious electronics without the
correct tools for the job?

I bought a small toaster oven from Argos for 20 GBP.

Leon
 
L

Leon

Jan 1, 1970
0
Thanks! That seems like a good place to buy tools. They've got good
pricing on Hakko as well. So I bookmarked them. But I can't use a fixed
temperature iron here in the lab because as a consultant I have to deal
with widely different technology.

The temperature is determined by the cartridge, you just need
different cartridges for different jobs. No calibration is required,
which is a big advantage in a production environment.

Leon
 
J

Joerg

Jan 1, 1970
0
Leon said:
The temperature is determined by the cartridge, you just need
different cartridges for different jobs. No calibration is required,
which is a big advantage in a production environment.

Ok, for production that is fine but not in my lab. I don't want to
switch cartridges or tips all the time. I remember the nasty burns I got
when changing between #6, #7 and #8 tips on the old non-adjustable Wellers.
 
J

Joerg

Jan 1, 1970
0
John said:
You Americans(?) are so lucky... here in the UK we have none of these
"toaster ovens" or "waffle irons" which seem to be so essential for
the serious constructor.

The most essential tool out here in the west is for after construction:
The Weber barbeque. Sure, by now you can also buy them in Europe but at
more than 3x the price (which is still worth it IMHO).

I mean, how can we be expected to do serious electronics without the
correct tools for the job?

I've seen them in Europe. Before I left Europe the most prevalent brand
for mini-ovens seemed to have been Moulinex.
 
Q

qrk

Jan 1, 1970
0
Thanks! That seems like a good place to buy tools. They've got good
pricing on Hakko as well. So I bookmarked them. But I can't use a fixed
temperature iron here in the lab because as a consultant I have to deal
with widely different technology.



My wife would not approve and I might not get waffles anymore ;-)

If you're used to the old Weller solder stations, you'll find that the
650 deg Metcal tip is equivalent to a 720 deg Weller temp setting for
small stuff (SMT and header pins). Metcal uses an induction heater
system to heat the tip directly and quickly, about 20 seconds from
cold to ready. Tip changes take 5 seconds as the tips slip on/off.

I also use the 750 deg 0.070" chisel tip for larger things. Of course,
I still keep my old Weller iron around for those bigger jobs or when I
need two irons to remove parts.
 
J

Joerg

Jan 1, 1970
0
Joel said:
Probably also at 3x the price? :)

The impression from my trip to Europe last month was that stuff over
there is still more expensive than here, especially after the USD slid.

I've seen dirt-cheap toaster ovens for $9.99 at Wal*Mart... incredible.

I am afraid those deals aren't going to last for much longer. Maybe we
have to get used to repair things again which wouldn't be all that bad.
However, the quality is often the pits. Last time after I repaired our
toaster it only hung on for another half year. Today my wife had to buy
a new one :-(

Hey, I don't watch much TV, but the other night they actually showed a public
service announcement-style ad, for "Guess what's going away in 2009? NTSC!
Get your converter box now... head on over to https://www.dtv2009.gov/ now!"

(Apologies for taking the thread off-topic...)

Got our coupons a couple weeks ago. So now I'll have to figure out which
converter from the eligibility is the best. My main concern is just what
I anticipated, multipath robustness.
 
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