Soldering TSOP/TSSOP devices

[Gary]

I don't have much experience with SMT and am now in a position where I have
to mount a TSSOP packaged device to complete a project. I'm on a low budget
(student) and have failed so far to locate a hobbyist group in my area that
might show me the way.

Does anyone have any experience in soldering TSSOP packages with VERY fine
lead pitch (Looks somewhere around 2.5 pins per milli)

I've heard about various methods but not sure which apply at this pitch.
Some involved rolling a ball of solder along the pins whilst trying to keep
surface tension. Others involve soldering across all the pins without
worrying about bridging, and then using a desolder braid to lift the
bridges.

I havent enough information on either of those techniques to actually put
them into practice. Sounds like there is far more involved than presented.


So, can anyone relate their experiences with fine pitched SMT, particularly
the lead pitch found in TSSOPs.

-What methods have you used ?
-What problems have you hit ?
-Which is the most reliable technique without resorting to rework stations.

Many many thanks in advance,


Gary.

 

[R. Steve Walz]

I don't have much experience with SMT and am now in a position where I have
to mount a TSSOP packaged device to complete a project. I'm on a low budget
(student) and have failed so far to locate a hobbyist group in my area that
might show me the way.

Does anyone have any experience in soldering TSSOP packages with VERY fine
lead pitch (Looks somewhere around 2.5 pins per milli)

I've heard about various methods but not sure which apply at this pitch.
Some involved rolling a ball of solder along the pins whilst trying to keep
surface tension. Others involve soldering across all the pins without
worrying about bridging, and then using a desolder braid to lift the
bridges.

I havent enough information on either of those techniques to actually put
them into practice. Sounds like there is far more involved than presented.

So, can anyone relate their experiences with fine pitched SMT, particularly
the lead pitch found in TSSOPs.

-What methods have you used ?
-What problems have you hit ?
-Which is the most reliable technique without resorting to rework stations.

Many many thanks in advance,

Gary.

------------
The only need is a high powered magnifier or microscope. Then it is
easy to learn to do this stuff. I use alternately, magnifier glasses
with add-on flip-up lenses in front, a magnifier lamp with glasses,
and a 30X binoc microscope. Then you develop your own suction, wick,
and hot-pin tips for your iron. You can solder each one down, or
flow and remove between and see it down to the fiberglass!

-Steve

 

[Mjolinor]

I don't have much experience with SMT and am now in a position where I have
to mount a TSSOP packaged device to complete a project. I'm on a low budget
(student) and have failed so far to locate a hobbyist group in my area that
might show me the way.

Does anyone have any experience in soldering TSSOP packages with VERY fine
lead pitch (Looks somewhere around 2.5 pins per milli)

I've heard about various methods but not sure which apply at this pitch.
Some involved rolling a ball of solder along the pins whilst trying to keep
surface tension. Others involve soldering across all the pins without
worrying about bridging, and then using a desolder braid to lift the
bridges.

I havent enough information on either of those techniques to actually put
them into practice. Sounds like there is far more involved than presented.


So, can anyone relate their experiences with fine pitched SMT, particularly
the lead pitch found in TSSOPs.

-What methods have you used ?
-What problems have you hit ?
-Which is the most reliable technique without resorting to rework stations.

Many many thanks in advance,


Gary.

This could be one long thread, everyone develops their own ideas of the best
way to do it and if it works for you then no one is qualified to say it's
not right. Personally I silver soldered a copper blade with a slight curve
on the face into the end of a normal soldering iron tip and I roll it over
the legs with solder paste on the pins then solderwick the excess off. Watch
the temperature of the chip, don't keep the iron on too long. I put a drop
of water on the top of the chip, if the chip is horizontal, and that way
it's easy to stop when the water drop gets small. There are literally
hudreds of different wys to do it.