Soldering technique
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Posts: 46,084
Sorry to post question here, as it is not strictly stamp related but
here goes. I want to rework my prototype product using SOIC packaged
devices for space savings. Are these hand solderable? Any special
techniques? Glue them to the board first, then solder with a fine tip
iron?
Any help appreciated!
Duncan Potter
Diacon Corp.
here goes. I want to rework my prototype product using SOIC packaged
devices for space savings. Are these hand solderable? Any special
techniques? Glue them to the board first, then solder with a fine tip
iron?
Any help appreciated!
Duncan Potter
Diacon Corp.
Comments
put solder on your tip you can wipe the pin/pad area fairly quickly to
solder the pins. The flux forces the wetting action and everything solders
nice. If you get a bridge add flux, wipe with a clean wiped tip and they
flow nice and clean.
Larry
At 08:27 PM 5/19/03 +0000, you wrote:
>Sorry to post question here, as it is not strictly stamp related but
>here goes. I want to rework my prototype product using SOIC packaged
>devices for space savings. Are these hand solderable? Any special
>techniques? Glue them to the board first, then solder with a fine tip
>iron?
>
>Any help appreciated!
>
>Duncan Potter
>Diacon Corp.
>
>
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http://www.robotroom.com/PCB3.html
-John
Original Message
From: diacon1208 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=j_5r0J81hwKYkonf7Z6MUdh3517G9gSuFYtb5cHAbmjrNb-AFK8_VPvIuVJJuCsZRxYA86ZphPxsP6wo6EUUBCs]dpotter@d...[/url
Sent: Monday, May 19, 2003 3:28 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Soldering technique
Sorry to post question here, as it is not strictly stamp related but
here goes. I want to rework my prototype product using SOIC packaged
devices for space savings. Are these hand solderable? Any special
techniques? Glue them to the board first, then solder with a fine tip
iron?
Any help appreciated!
Duncan Potter
Diacon Corp.
To UNSUBSCRIBE, just send mail to:
basicstamps-unsubscribe@yahoogroups.com
from the same email address that you subscribed. Text in the Subject
and Body of the message will be ignored.
Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
I recently took a 40-hr SMT soldering class and they say I am now certified
at Class 3 level (medical equipment, etc.). You wouldn't want me assembling
your pacemaker, though! After working with various techniques on a fancy
Pace soldering station, here is my current favorite method for doing
standard pitch SOICs...
First, the #1 soldering secret is: LIQUID FLUX!!! Get some liquid rosin
flux (not the highly activated kind), and use it liberally. I once thought
the flux in the solder was all you needed, especially for through-hole work,
but wow, what a difference!
Another couple things... a fine tip at about 600 degrees F is about right.
Most inexpensive pencil irons tend to be too hot. Fine solder is also
helpful for control. I tended to apply too much solder to get the nice
fillets, and the finer solder wire makes it easier. After working with as
fine as .010" solder, I settled on .015 to .020" for most SMT work. Many of
the photos of SMT work I see have too much solder applied, which prevents
proper visual inspection to determine if the joint is good. You want to be
able to see the outline of the "feet" on the pads, and have a nice radiused
fillet of solder. Liquid flux and fine solder help a lot.
You can do it with the naked eye, but magnification makes a tremendous
difference, especially for inspecting the quality of your joints. Even the
common 2x to 3x magnifiers, with the circular fluorescent bulbs surrounding
the lenses help quite a bit. We used Nikon dual-eyepiece zoom microscopes,
and they were awesome. I am completely spoiled, but cannot justify buying
one for my own use. Fortunately, I'm teaching a couple classes there this
coming year and will have access to the soldering lab ;-)
You also should have some alcohol and a brush for cleaning off the flux.
Isopropyl is recommended, but denatured (ethyl) can be used. Horse hair
cleaning brushes work fine. Some lint-free cleaning tissues are also handy.
I first like to apply flux to two diagonally-opposed corner pads, and then
apply a little solder to the pads. Just enough to make a slight crown.
Apply more flux to the solder. Now position the part with tweezers, and
touch the iron to one of the corner leads/pads where you had applied the
solder. The solder should melt and flow over the "foot" of the lead, making
a nice joint. Adequate flux is the key. If the alignment looks good so
far, do the same to the opposite corner where you had also applied solder to
the pad. Check your lead/pad alignment one last time. Once you proceed
from this point, it will be a lot more work to re-align the part. Apply
flux to all the remaining pads...
Now you have a couple options. You can solder each lead/pad individually.
Be careful to not use too much solder. With practice, you can slide your
tip along the row, pausing a couple seconds at each joint. With the right
tip, flux, solder and technique, this works beautifully (and fast). A nice
tip shape is an oval. Pace calls it a "mini-wave." Imagine a conical tip
where the end was cut off at an angle, resulting in a flat oval. Apply some
solder to the oval, and slide it along the row. With a little practice,
your joints will be beautiful and the work will go quickly.
Have fun!
Randy Jones
www.glitchbuster.com
Original Message
From: "diacon1208" <dpotter@d...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, May 19, 2003 1:27 PM
Subject: [noparse][[/noparse]basicstamps] Soldering technique
> Sorry to post question here, as it is not strictly stamp related but
> here goes. I want to rework my prototype product using SOIC packaged
> devices for space savings. Are these hand solderable? Any special
> techniques? Glue them to the board first, then solder with a fine tip
> iron?
>
> Any help appreciated!
>
> Duncan Potter
> Diacon Corp.
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
Apparently you use a water-soluble solder paste from Kester Solders
to cover the pads on the board, set your chips down, and bake it for
a while in your toaster oven to 'cure' it. I've never used the
method but might be worth a try.
Let me know if you use it and it works. Here is the link:
http://www.seattlerobotics.org/encoder/200006/oven_art.htm
Ron
--- In basicstamps@yahoogroups.com, "diacon1208" <dpotter@d...> wrote:
> Sorry to post question here, as it is not strictly stamp related
but
> here goes. I want to rework my prototype product using SOIC
packaged
> devices for space savings. Are these hand solderable? Any special
> techniques? Glue them to the board first, then solder with a fine
tip
> iron?
>
> Any help appreciated!
>
> Duncan Potter
> Diacon Corp.
ovens! Looks pretty neat. Let me know if you try it and if it work!
http://www.seattlerobotics.org/encoder/200006/oven_art.htm
Ron
--- In basicstamps@yahoogroups.com, "diacon1208" <dpotter@d...> wrote:
> Sorry to post question here, as it is not strictly stamp related
but
> here goes. I want to rework my prototype product using SOIC
packaged
> devices for space savings. Are these hand solderable? Any special
> techniques? Glue them to the board first, then solder with a fine
tip
> iron?
>
> Any help appreciated!
>
> Duncan Potter
> Diacon Corp.
IC. Over time when current passes within the "wires" inside of an IC,
a phenomenon called "metal migration" occurs within the IC eventually
leading to failure. The toaster is a bad idea, acting as a catalyst
towards this phenomenon.
-Beau Schwabe
>Check this site out. They're doing SMT soldering with toaster
>ovens! Looks pretty neat. Let me know if you try it and if it work!
>
>http://www.seattlerobotics.org/encoder/200006/oven_art.htm
>
>Ron
>
>--- In basicstamps@yahoogroups.com, "diacon1208" <dpotter@d...> wrote:
> > Sorry to post question here, as it is not strictly stamp related
>but
> > here goes. I want to rework my prototype product using SOIC
>packaged
> > devices for space savings. Are these hand solderable? Any special
> > techniques? Glue them to the board first, then solder with a fine
>tip
> > iron?
> >
> > Any help appreciated!
> >
> > Duncan Potter
> > Diacon Corp.
shuttle. For hobbiest work the toaster oven works perfectly well.
Really isn't that much different than a commercial reflow oven other
than the dewll time at high temp. Besides by the time the IC has
degraded enough to fail it is more than likely collecting dust in a
museum somewhere.
The only real problem with plastic parts is the fact that they take
on moisture. This moisture can cause steam pockets inside the IC and
build up enough pressure to crack the die or break bond wires when
reflowing. That is why most are shipped with a vacuum pack static bag
with a date code on them. Store open parts in a dry, heated room.
Bake the parts for 24 hours at 40C before reflow to prevent moisture
damage.
I have found that with a few prototypes hand soldering with a good
Metcal iron and a selection of fine and curved tips can be just as
fast. Kester no clean liquid soldering flux is a must when soldering
down fine pitch parts. I can solder down a 208 pin QFP in less than 5
minutes flat by hand.
Jason
--- In basicstamps@yahoogroups.com, "Beau Schwabe" <bschwabe@a...>
wrote:
> This might work If you want to dramatically decrease the life of the
> IC. Over time when current passes within the "wires" inside of an
IC,
> a phenomenon called "metal migration" occurs within the IC
eventually
> leading to failure. The toaster is a bad idea, acting as a catalyst
> towards this phenomenon.
>
> -Beau Schwabe
>
> >Check this site out. They're doing SMT soldering with toaster
> >ovens! Looks pretty neat. Let me know if you try it and if it
work!
> >
> >http://www.seattlerobotics.org/encoder/200006/oven_art.htm
> >
> >Ron
> >
> >--- In basicstamps@yahoogroups.com, "diacon1208" <dpotter@d...>
wrote:
> > > Sorry to post question here, as it is not strictly stamp related
> >but
> > > here goes. I want to rework my prototype product using SOIC
> >packaged
> > > devices for space savings. Are these hand solderable? Any
special
> > > techniques? Glue them to the board first, then solder with a
fine
> >tip
> > > iron?
> > >
> > > Any help appreciated!
> > >
> > > Duncan Potter
> > > Diacon Corp.