Desolder station advice

T

Theo Markettos

Guest
Our research lab is in the market for a desoldering station. My personal
interest is in desoldering SMDs of various types, but being research it's
hard to plan what we might want to do with it next so having some
flexibility is useful. Often we want to preserve both the board and the
component so something that won't cause damage would be useful. It's not
going to be heavily used, but ideally something that's reliable and can be
used by novices.

I see there are two types of station: those with special tips shaped for the
particular component to be desoldered (TQFP64, SSOP28 etc) and hot air
rework stations. Can anyone advise why to choose one over the other? The
disadvantage of the special tips model is that either we invest in all of
them, or have to order when we find we need them which will slow things
down.

Anyone recommend any particular models/brands? Budget is about 2000ukp.

Thanks
Theo
 
In article <thz*ZGsor@news.chiark.greenend.org.uk>,
Theo Markettos <theom+news@chiark.greenend.org.uk> wrote:

Our research lab is in the market for a desoldering station. My personal
interest is in desoldering SMDs of various types, but being research it's
hard to plan what we might want to do with it next so having some
flexibility is useful. Often we want to preserve both the board and the
component so something that won't cause damage would be useful. It's not
going to be heavily used, but ideally something that's reliable and can be
used by novices.

I see there are two types of station: those with special tips shaped for the
particular component to be desoldered (TQFP64, SSOP28 etc) and hot air
rework stations. Can anyone advise why to choose one over the other? The
disadvantage of the special tips model is that either we invest in all of
them, or have to order when we find we need them which will slow things
down.

Anyone recommend any particular models/brands? Budget is about 2000ukp.

Thanks
Theo
Click to expand...
enought for a weller rework station...use hot air not to destroy the
chips... eventually use jbc nozzles to pull the chips up. this protects
the others chips around and are cheaper (some 15 euros the twizzle and
50 euros the nozzle)
regards

--
Jean-Yves.
 
"Theo Markettos" <theom+news@chiark.greenend.org.uk> wrote in message
news:thz*ZGsor@news.chiark.greenend.org.uk...
I see there are two types of station: those with special tips shaped for
the
particular component to be desoldered (TQFP64, SSOP28 etc) and hot air
rework stations. Can anyone advise why to choose one over the other?
Click to expand...
With hot air, I've personally found it difficult to desolder a part quickly
enough that other parts aren't damaged. I think that hot air works best if
you have a preheat station, so that the whole board is warm enough that the
hot air nozzle just tips it over the edge.

Even with hot air, you do end up having to buy a bunch of different nozzles
for different shaped parts. However, you can usually buy a kit that has the
station and a bunch of nozzles.

On a related note, I've also found that the cheap hot tweezers (eg the
Xytronics sold by Circuit Specialties) don't seem to work very well. The
tips just don't conduct enough heat; the heating elements are in the "arms",
too far from the tips.
 
I have used hot air desoldering commercial equipment, the "PASS" system does
an excellent job of component removal with minimal damage to either the
device or the boards. Consideration for commercial use and for efficiency
may point you to the hot air, vacuum type of system.
"Walter Harley" <walterh@cafewalterNOSPAM.com> wrote in message
news:af-dnSnhVs_N_HjZnZ2dnUVZ_umdnZ2d@speakeasy.net...
"Theo Markettos" <theom+news@chiark.greenend.org.uk> wrote in message
news:thz*ZGsor@news.chiark.greenend.org.uk...
I see there are two types of station: those with special tips shaped for
the
particular component to be desoldered (TQFP64, SSOP28 etc) and hot air
rework stations. Can anyone advise why to choose one over the other?

With hot air, I've personally found it difficult to desolder a part
quickly enough that other parts aren't damaged. I think that hot air
works best if you have a preheat station, so that the whole board is warm
enough that the hot air nozzle just tips it over the edge.

Even with hot air, you do end up having to buy a bunch of different
nozzles for different shaped parts. However, you can usually buy a kit
that has the station and a bunch of nozzles.

On a related note, I've also found that the cheap hot tweezers (eg the
Xytronics sold by Circuit Specialties) don't seem to work very well. The
tips just don't conduct enough heat; the heating elements are in the
"arms", too far from the tips.
Click to expand...
 
My experience with hot air has been excellent. Trick is to set temp and
airflow high enough to do the job quickly but not blow everything else off.
I solder everything except BGAs with a hot air
sometimes you need to use shields.

Experience with tweezers types was not so good
Elements eventually develop faults that force current through parts and can
cause the components in question to fail as well as others connected to them
through their common nets...
Not cool.
I use a cheap Chinese made station
http://www.cutter.com.au/products.php?cat=9&pg=5

model CT-953D
$380 US and nozzles are $14 each
with the budget you have you could get a decent microscope to boot!

cheers

"Art" <plotsligt@comcast.net> wrote in message
news:hZ6dncdo3d7_EXjZnZ2dnUVZ_tGdnZ2d@comcast.com...
I have used hot air desoldering commercial equipment, the "PASS" system
does an excellent job of component removal with minimal damage to either
the device or the boards. Consideration for commercial use and for
efficiency may point you to the hot air, vacuum type of system.
"Walter Harley" <walterh@cafewalterNOSPAM.com> wrote in message
news:af-dnSnhVs_N_HjZnZ2dnUVZ_umdnZ2d@speakeasy.net...
"Theo Markettos" <theom+news@chiark.greenend.org.uk> wrote in message
news:thz*ZGsor@news.chiark.greenend.org.uk...
I see there are two types of station: those with special tips shaped for
the
particular component to be desoldered (TQFP64, SSOP28 etc) and hot air
rework stations. Can anyone advise why to choose one over the other?

With hot air, I've personally found it difficult to desolder a part
quickly enough that other parts aren't damaged. I think that hot air
works best if you have a preheat station, so that the whole board is warm
enough that the hot air nozzle just tips it over the edge.

Even with hot air, you do end up having to buy a bunch of different
nozzles for different shaped parts. However, you can usually buy a kit
that has the station and a bunch of nozzles.

On a related note, I've also found that the cheap hot tweezers (eg the
Xytronics sold by Circuit Specialties) don't seem to work very well. The
tips just don't conduct enough heat; the heating elements are in the
"arms", too far from the tips.
Click to expand...
 
newinwa <w_e_coyote_sg@hotmail.com> wrote:
I solder everything except BGAs with a hot air
sometimes you need to use shields.
Click to expand...
Do you improvise the shields or are these a special tool somewhere?

I use a cheap Chinese made station
http://www.cutter.com.au/products.php?cat=9&pg=5

model CT-953D
$380 US and nozzles are $14 each
with the budget you have you could get a decent microscope to boot!
Click to expand...
Nice. At that price I could almost afford one myself :) Shipping one from
..au to .uk is perhaps a little silly though...

Theo
 
Art <plotsligt@comcast.net> wrote:
I have used hot air desoldering commercial equipment, the "PASS" system
does an excellent job of component removal with minimal damage to either
the device or the boards. Consideration for commercial use and for
efficiency may point you to the hot air, vacuum type of system.
Click to expand...
Could you explain what the "PASS" system is? I didn't get anywhere with
Googling - do you mean Pace?. Are you saying that you'd use hot air, unless
you had to do high-throughput work in which case you'd go for hot air and
vacuum? Or do I misunderstand?

I've seen vacuum tools which are just like old fashioned spring-loaded
solder suckers but a vacuum pump instead of a spring - they don't look much
use to me (I can wick/suck most of the solder off, but the device is still
stuck to the board with the last few drops). I presume by vacuum you mean
vacuum to pick up components once they're heated?

Also what sort of wattage is recommended for a general purpose system? I
notice Weller here:
http://www.cooperhandtools.com/europe/electronics_products/weller/hotair/documents/HotAirBrochure_GB_000.pdf
differentiate between 700W and 100W systems, saying 100W is for 'smaller SMD
components'. What's 'smaller'? A 0402 resistor or a QFP100?

Pace's systems look nice (looking at ST325), though why the tips are all
80ukp each is beyond me :( They don't suggest a selection of useful tips
either.

Thanks for the suggestions
Theo
 
That is the nomenclature they used in the facility that I was involved with,
Sorry Mate, should have looked at the flipppin addy, Down Under!! Maybe a
pint of Fosters will cover that oversight. The other information that has
been posted is viable, I'm certain that in Australia you certainly can find
suitable item without having Quanta's bring it in. Cheers Gov.
"Theo Markettos" <theom+news@chiark.greenend.org.uk> wrote in message
news:QXB*l0xor@news.chiark.greenend.org.uk...
Art <plotsligt@comcast.net> wrote:
I have used hot air desoldering commercial equipment, the "PASS" system
does an excellent job of component removal with minimal damage to either
the device or the boards. Consideration for commercial use and for
efficiency may point you to the hot air, vacuum type of system.

Could you explain what the "PASS" system is? I didn't get anywhere with
Googling - do you mean Pace?. Are you saying that you'd use hot air,
unless
you had to do high-throughput work in which case you'd go for hot air and
vacuum? Or do I misunderstand?

I've seen vacuum tools which are just like old fashioned spring-loaded
solder suckers but a vacuum pump instead of a spring - they don't look
much
use to me (I can wick/suck most of the solder off, but the device is still
stuck to the board with the last few drops). I presume by vacuum you mean
vacuum to pick up components once they're heated?

Also what sort of wattage is recommended for a general purpose system? I
notice Weller here:
http://www.cooperhandtools.com/europe/electronics_products/weller/hotair/documents/HotAirBrochure_GB_000.pdf
differentiate between 700W and 100W systems, saying 100W is for 'smaller
SMD
components'. What's 'smaller'? A 0402 resistor or a QFP100?

Pace's systems look nice (looking at ST325), though why the tips are all
80ukp each is beyond me :( They don't suggest a selection of useful tips
either.

Thanks for the suggestions
Theo
Click to expand...
 
Art <plotsligt@comcast.net> wrote:
That is the nomenclature they used in the facility that I was involved
with, Sorry Mate, should have looked at the flipppin addy, Down Under!!
Maybe a pint of Fosters will cover that oversight. The other information
that has been posted is viable, I'm certain that in Australia you
certainly can find suitable item without having Quanta's bring it in.
Cheers Gov.
Click to expand...
Thanks for the feedback everyone. The two options I've put forward are the
OK Industries HCT-900:
http://www.okinternational.com/product_convection/hct_900
(400ukp plus nozzles, total 600-800ukp)

or the Pace ST325
http://www.paceworldwide.com/documents/SMT_AreaArrayBro%20final%2024%20May%2006.pdf
(930ukp plus nozzles, total 1400-1800ukp)

It's up for debate whether we need temperature profiles and vacuum pickup,
which are the main features of the more expensive model. I still don't
understand why nozzles are quite so expensive though...

Theo
 
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