OMG you won't believe what I just soldered!

[rocketsonly]

For those of you who are familar with electronics, I just soldered a 10 pin uSOP/uMAX package integrated circuit onto a board without bridges!

For those of you who don't know much about electronics, a 10 pin uSOP package contains 5 pins on each side of the chip, and has a pin pitch (center to center) of 0.5mm (or 0.0197").

Isn't that crazy??

 

[Ozymandias]

I hope you used a heat sink.

 

[rocketsonly]

Nope, but I did make sure I got in and out quickly. All the connections are good though! We'll find out if I fried anything by Monday.

Haha, for some reason I knew you were going to reply to my message.

 

[n3tjm]

gotta love soldering those small parts....

 

[edwardw]

Sometimes it is easier to just let it bridge, then go back with braided wick and get it off. Takes less time and there is less heat to the part usually. Oh, and use a really high watt soldering iron.

Edward

 

[rocketsonly]

Originally posted by edwardw
Sometimes it is easier to just let it bridge, then go back with braided wick and get it off. Takes less time and there is less heat to the part usually. Oh, and use a really high watt soldering iron.

Edward

Haha, Edward, you're kidding, right? A really high wattage iron would kill/destroy the chip.

 

[rstaff3]

Soldering...BAH...if I can't wirewrap it, I won't build it! (or maybe that's can't)

 

[Reed Goodwin]

I built a calculator for my 8th grade science project. Big old thing that could multiply numbers up to 7 times 15. I had a whole butt-load of ICs that had to be soldered and so to minimize the risk of damaging the chips, I soldered IC sockets to the board and then just plugged the ICs in. The neat thing was, I designed the entire circuit by myself without any special software. I only got help from my dad in getting the actual logic down. Fun fun...
Reed

 

[edwardw]

No, actually a hotter iron lets you solder much faster. You can get in, out quicker because it melts the solder faster

Edward

 

[rocketsonly]

Originally posted by edwardw
No, actually a hotter iron lets you solder much faster. You can get in, out quicker because it melts the solder faster

Edward

True, but the pros of using a hotter iron only go so far. From all of the research I have done, it is suggested to not go over a 15w iron (standard irons are about 30w).

 

[edwardw]

Yea, but a small pencil tip (.5mm) and a hot iron can solder stuff very very fast. I did it for a job for quite a while on second shift. I had a 99% reliability on my boards I put together. Most of us were very good. If you got below 97% you lost your job....kind of one of those 'unspoken' rules.

Edward

 

[OccamMD]

Congratulations, I remember how good it feels to get that first one right!!!

I solder uSOP fairly often @ 750 degrees. I use a standard tip, not a small conical, for almost all SMT. Flux the board, set down the chip, flux the chip leads and tack 1 down in the corner. Then melt a small bead of solder on the tip and touch the pad, then roll up to the very tip of the pin, should wick right in. once your done the first time (bridges and all) just reflux and touch each pad/pin (both at the same time to heat them both) one at a time, surface tension will pull the solder to the pin and get a nice rounded joint. Should only need to touch the pad for a second, not long.

I have a tech friend that is way better at this and he flux's, bridges most of it without caring, fluxes again, then goes back and straffes the bottom edges of the pins at about a 1/4" per second for large parts. Comes out perfect!

 

[rocketsonly]

Originally posted by OccamMD
Congratulations, I remember how good it feels to get that first one right!!!

I solder uSOP fairly often @ 750 degrees. I use a standard tip, not a small conical, for almost all SMT. Flux the board, set down the chip, flux the chip leads and tack 1 down in the corner. Then melt a small bead of solder on the tip and touch the pad, then roll up to the very tip of the pin, should wick right in. once your done the first time (bridges and all) just reflux and touch each pad/pin (both at the same time to heat them both) one at a time, surface tension will pull the solder to the pin and get a nice rounded joint. Should only need to touch the pad for a second, not long.

I have a tech friend that is way better at this and he flux's, bridges most of it without caring, fluxes again, then goes back and straffes the bottom edges of the pins at about a 1/4" per second for large parts. Comes out perfect!

Interesting! I'll have to try that out.

 

[LFLekx]

I saw an article on an electronics-hobbyist site that described a method for using a toaster-oven to solder all your SMT parts at once.

Apply solder-paste to the pads, pop the parts in place, and shove the whole thing into a heated toaster-oven. After about fifteen minutes, the paste has melted in such a way that the joints are all done... with no bridges at all.

Have to see if I can find it again...

 

[Hospital_Rocket]

That's what we used to call reflow soldering, We used to use a syringe to dab on an Indium paste solder, then the part would be glued down. A blast of hot air would melt the solder and create the joint.

Kind of a neat way to assemble electronics.

A

 

[OccamMD]

Check the thermal ratings on the parts first. Many are spec'd for high temp for a short period of time for assembly, 15 minutes isn't short.

 

[rocketsonly]

Originally posted by LFLekx
I saw an article on an electronics-hobbyist site that described a method for using a toaster-oven to solder all your SMT parts at once.

Apply solder-paste to the pads, pop the parts in place, and shove the whole thing into a heated toaster-oven. After about fifteen minutes, the paste has melted in such a way that the joints are all done... with no bridges at all.

Have to see if I can find it again...

This? https://www.seattlerobotics.org/encoder/200006/oven_art.htm

 

[Ozymandias]

Originally posted by rocketsonly
Haha, Edward, you're kidding, right? A really high wattage iron would kill/destroy the chip.

No, actually you will end up applying less heat to the component because you can work quicker. You won't have wait for the solder to melt. I do all my PCB stuff I keep the tip at about 800˚f which allows me to do ICs and DIP sockets really fast (using a heat sink is also a good idea). If my hands are steady enough I don't accidently bridge anything. If you plan to do a lot of soldering, I'd invest in a good soldering station like a Weller, Ungar, or Edsyn. You'll never go back. If you search eBay you can probably find a nice used Ungar station for a good price. My Edsyn was $150 and I love it. I can do everything from R/C cars to teeny-tiny SMT stuff with it. It's also important to use a good solder. A good solder will wick into the connection well and you won't have to do any "touch-ups". I like Alphametals Guideline solder for PCBs and I use Dean's Racing solder for my cars and robots.