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Hand Soldering

I'm a EE student at Cornell working on a research project. We have to
do a significant amount of hand soldering for the project. Which chip
packages are hand solderable? I need to know what I can purchase
from, say, DigiKey and actually solder. Examples of packages I'm
interested in are:
* DIP
* SIP
* SOT
* SOIC
* SSOP
* TSSOP
* QFN
* TDFN

I know it depends on equipment and skill. I've done some soldering
before, but not much. We have medium quality soldering irons (not
tiny tips) and basic magnification (no microscopes).

Thanks,
-J
 
M

Marra

Jan 1, 1970
0
I'm a EE student at Cornell working on a research project. We have to
do a significant amount of hand soldering for the project. Which chip
packages are hand solderable? I need to know what I can purchase
from, say, DigiKey and actually solder. Examples of packages I'm
interested in are:
* DIP
* SIP
* SOT
* SOIC
* SSOP
* TSSOP
* QFN
* TDFN

I know it depends on equipment and skill. I've done some soldering
before, but not much. We have medium quality soldering irons (not
tiny tips) and basic magnification (no microscopes).

Thanks,
-J

Given a small enough tip you can solder pretty much anything.

www.ckp-railways.talktalk.net/pcbcad28.htm
 
J

John Larkin

Jan 1, 1970
0
I'm a EE student at Cornell working on a research project. We have to
do a significant amount of hand soldering for the project. Which chip
packages are hand solderable? I need to know what I can purchase
from, say, DigiKey and actually solder. Examples of packages I'm
interested in are:
* DIP
* SIP
* SOT
* SOIC
* SSOP
* TSSOP
* QFN
* TDFN

I know it depends on equipment and skill. I've done some soldering
before, but not much. We have medium quality soldering irons (not
tiny tips) and basic magnification (no microscopes).

Thanks,
-J

They're all hand solderable. The real indicator of difficulty is lead
pitch. 50 mils is easy; 20 mils takes more care and skill, and careful
post-inspection for solder bridges. Since you're not likely to want to
spend a lot of time practicing, try to use dip or larger-pitch parts
for now.

The leadless parts are a bitch, and bga's are impossible to hand
solder.

What are you building?

John
 
R

Randy Day

Jan 1, 1970
0
I'm a EE student at Cornell working on a research project. We have to
do a significant amount of hand soldering for the project. Which chip
packages are hand solderable? I need to know what I can purchase
from, say, DigiKey and actually solder. Examples of packages I'm
interested in are:
* DIP
* SIP
* SOT
* SOIC
* SSOP
* TSSOP
* QFN
* TDFN

I know it depends on equipment and skill. I've done some soldering
before, but not much. We have medium quality soldering irons (not
tiny tips) and basic magnification (no microscopes).

TDFN has all pins under the device.

Attaching any of the rest to a PCB can be
done by hand with a soldering iron and a
light touch, but if you're *removing*
parts? Only the first four.

You might get the rest off a board with
lots of solder wick, but you'll likely
take a few traces with it...
 
R

Rich Webb

Jan 1, 1970
0
snip...]
I know it depends on equipment and skill. I've done some soldering
before, but not much. We have medium quality soldering irons (not
tiny tips) and basic magnification (no microscopes).

Thanks,
-J

They're all hand solderable. The real indicator of difficulty is lead
pitch. 50 mils is easy; 20 mils takes more care and skill, and careful
post-inspection for solder bridges.

As John says, 20 mil (0.5 mm) pitch is quite do-able by hand with a
modicum of care. An Optivisor (a.k.a. geek helmet ;-) is useful. A
medium tip is also fine; better, actually, for "wave tip" soldering,
where a bead of solder is drawn across the package leads.

Some useful tutorials at
http://www.sparkfun.com/commerce/hdr.php?p=tutorials

If you don't have access to a rework station (I've become a True
Believer for hot air), a ChipQuik starter kit might be a good
investment if you do work with the many-legged SMT devices.
Since you're not likely to want to
spend a lot of time practicing, try to use dip or larger-pitch parts
for now.

Good advice...
 
J

Jon Slaughter

Jan 1, 1970
0
I'm a EE student at Cornell working on a research project. We have to
do a significant amount of hand soldering for the project. Which chip
packages are hand solderable? I need to know what I can purchase
from, say, DigiKey and actually solder. Examples of packages I'm
interested in are:
* DIP
* SIP
* SOT
* SOIC
* SSOP
* TSSOP
* QFN
* TDFN

I know it depends on equipment and skill. I've done some soldering
before, but not much. We have medium quality soldering irons (not
tiny tips) and basic magnification (no microscopes).

Thanks,
-J


(This is only needed for small pitch)

You can do all of them. The easiest way I've found(although I'm by far an
expert at it) is to pre-solder the pads and remove as much solder from the
pads as possible(use wick). Then just put the IC on the pads and heat the
leads(use flux). It sticks pretty well and I have yet to have any pins not
make good contact. I suppose its not the best method but seems to work well.
Trying to solder the pins after the fact is a mess IMO and takes about 10x
longer for very low pitch.

I imagine you could also use hot air or some other method but this, IMO,
seems the easiest if you don't have something better. You can check for
mechanical connection by using a continuity tester. If any pins don't stick
then you can always add a little solder to the tip and reheat the pin.

You would be supprised what you can solder. When I first tried SMT I was
nervious but its actually not all that difficult once you get the hang of
it.
 
R

Rich Webb

Jan 1, 1970
0
Attaching any of the rest to a PCB can be
done by hand with a soldering iron and a
light touch, but if you're *removing*
parts? Only the first four.

You might get the rest off a board with
lots of solder wick, but you'll likely
take a few traces with it...

ChipQuik really works for this, although I haven't personally used it
on larger than 48 pin LQFP devices (and I prefer hot air now, having
gotten the necessary gizmo). It's even possible to re-use the removed
device (after cleaning) if it turns out that the problem was elsewhere
in the circuit (like THAT ever happens).

Not recommended for more than occasional use, since it's relatively
expensive (in the neighborhood of US$5 per foot) and a quad pack
probably takes 2" to 4".

Usual disclaimer: just a customer who buys too many gadgets...
 
J

John G

Jan 1, 1970
0
John Larkin said:
They're all hand solderable. The real indicator of difficulty is lead
pitch. 50 mils is easy; 20 mils takes more care and skill, and careful
post-inspection for solder bridges. Since you're not likely to want to
spend a lot of time practicing, try to use dip or larger-pitch parts
for now.

The leadless parts are a bitch, and bga's are impossible to hand
solder.

What are you building?

John

A related question from someone who only does the odd (sometimes Very
Odd) repair these days.

Can RHoS certified components (Resistors etc) be succesfully soldered
with ordinary old solder and reasonable Weller Iron?
John G.
 
D

DJ Delorie

Jan 1, 1970
0
* DIP
* SIP
* SOT
* SOIC
* SSOP
* TSSOP
* QFN
* TDFN

I've done all of these by hand, although I tend to use solder paste
and a hotplate for most SMT work these days, especially the "FN"
packages, where the connections are under the chip. Also, even with
the iron, for SMT resistors and capacitors I find it much easier to
apply a dab of solder paste to each pad, put the part on it, and then
melt the paste with the iron; than to try to use wire solder for that
task.

A fine tip on the iron and some form of magnifier (I also use an
optivisor) is key to doing small parts by hand.

As for size, I've hand soldered (with an iron) down to 01005 caps
(0.016" x 0.008"), and 0.4mm (16 mil) pitch ICs. It's not fast,
though. For most boards, using a stencil, solder paste, and a cheap
hotplate or electric skillet will be much faster and easier.
 
R

Randy Day

Jan 1, 1970
0
John said:
A related question from someone who only does the odd (sometimes Very
Odd) repair these days.

Can RHoS certified components (Resistors etc) be succesfully soldered
with ordinary old solder and reasonable Weller Iron?
John G.

Absolutely. Standard solder works just
fine. You just can't call it RoHS and
sell it in Europe...
 
J

John Fields

Jan 1, 1970
0
I'm a EE student at Cornell working on a research project. We have to
do a significant amount of hand soldering for the project. Which chip
packages are hand solderable? I need to know what I can purchase
from, say, DigiKey and actually solder. Examples of packages I'm
interested in are:
* DIP
* SIP
* SOT
* SOIC
* SSOP
* TSSOP
* QFN
* TDFN

I know it depends on equipment and skill. I've done some soldering
before, but not much. We have medium quality soldering irons (not
tiny tips) and basic magnification (no microscopes).

---
For prototype surface mount packages I flux everything up first,
then I use a times ten visor to line up the chip as best I can in X
and Y. Then, when everything looks good, I tack down one corner.

If, after that, everything still looks good I tack down the
diagonally opposite corner so that all of the pins fall on their
respective traces.

I don't do RoHS and I get my PCB's plated Sn63 SMOBC, so a touch of
the iron on the pin over the fluxed trace melts the plating and
solders the pin to the pad/trace.
 
J

John G

Jan 1, 1970
0
Randy Day said:
Absolutely. Standard solder works just
fine. You just can't call it RoHS and
sell it in Europe...

Thanks. I do not sell things anywhere, only do repairs and gadget type
things, often for disabled clients thru a Sydney Australia charity
called Technical Aid to the Disabled.

John G.
 
J

john jardine

Jan 1, 1970
0
I'm a EE student at Cornell working on a research project. We have to
do a significant amount of hand soldering for the project. Which chip
packages are hand solderable? I need to know what I can purchase
from, say, DigiKey and actually solder. Examples of packages I'm
interested in are:
* DIP
* SIP
* SOT
* SOIC
* SSOP
* TSSOP
* QFN
* TDFN

I know it depends on equipment and skill. I've done some soldering
before, but not much. We have medium quality soldering irons (not
tiny tips) and basic magnification (no microscopes).

Thanks,
-J

If you get a kick out of watchmaking, egg implantation, keyhole gynaecology
and have suitable kit, then all the types are approachable.
For normal humans, DIP, SIP.
The remainder are spawn of the devil, not meant to be touched by human hand
and an utter pain the arse.
 
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