hi,

i received my order online from ti. its placed in an antistatic bag (as usual) but this time, the bag is completely sealed and it has a red sticker which says:
its actually a uln2803adwr (soic). is there a special way of soldering this stuff???? its the first time i encountered such a thing!
if the temperature is of concern, well the lowest temp in my place is 28°C and the highest temp is 37°C. right now temp falls between 30-37.

how will i be able to solder this thing? is there a special way of dealing with this??? :roll: :cry: :?:

 

My knowledge in this area is limited and dated however I recall several things.

I seem to remember that some fluxes absorbed water at an incredible rate and that they might release that water rapidly upon heating (during soldering. In a production situation that might result in a relatively high humidity.

Another recollection - some production operations include washing or rinsing of flux with hot water.

__________________
stevez

 

hmmm... you have mentioned it in a production environment.

does that mean i have nothing to worry about? since i would only be doing hobbyist stuff, which obviously is only done at home...

:roll: :roll: :roll:

 

Well it does say "TAKE CARE TO PREVENT DAMAGE WHEN VAPOR OR IR SOLDERING" - are you doing either of those?.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

This is TI's "CYA" method of saying that part has a very poor moisture sensitivity level (MSL) rating. And as such, when it sits on the shelf for a long time, the part will absorb moisture over time.

Then when you rapidly heat the part while soldering, the moisture violently escapes providing a new mode of operation - The rapid disassembly mode. i.e it cracks! ;-)

By baking the part prior, you "gently" allow the mosture to escape and then you'll be ready to put the rapid T-rise to it.

 

You gotta love it!!!

 

wait, wait, wait...

i don't get the baking thing, and the rapid heating process during soldering :shock: :roll:

does that mean i "cannot" solder it at home level??? how will i bake it? :roll:

 

Did you read my previous post? - try reading it again!.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

Just take care.. you are probably not capable of generating such steep rates of temperature rise at home anyhow.
The warning is intended for production environments where there are systems that could potentially destroy the parts in this way.

I wouldn't worry about it..

 

ok, so at home level, its just an ordinary surface mount ic that needs to be soldered the "usual way"? am i right?

 

Hi,

if you're worried about it,
just leave it open somewhere warm overnight,
to make sure it dries out.

personally i wouldn't worry.

John

 

yup, had loads of ic's with same warning, no sweat.. Just warm it a bit, if your worried, I never bother, as I don't remove it from its packaging until its soldered in. Never had one fail yet. This is more inline with production assembly lines, where the IC's are more exposed to environment (not in little sealed bags

Steve

 

can i place it under the sun for a few hours (its quite hot now in my country because its summer)???