Surface Mount Soldering

Ricardus · Mar 16, 2021

I've never done it before.

This OpAmp I'm about to build spec'd a SMT transistor because the through hole (MAT01's, etc) are $20-$30. (yes, he is aware of AS394s).

Wish me luck. Here goes nothing. Got my 3.2 mm tip, my plumbing solder, and my paste flux ready to go!

JohnRoberts · Mar 16, 2021

I did tons of smd rework using my old school weller iron for several years before I finally upgraded to a hot air station. I am on my second hot air station since the first cheap Chinese hot air station already failed.

Not a big deal, be careful.

JR

rob_gould · Mar 16, 2021

Yes, I've also managed a fair bit of smt with a 15 euro soldering iron and a fairly chunky chisel tip. It's pretty doable unless it's the really tiny stuff.

Good luck!

Ricardus · Mar 16, 2021

I'm only kidding about the big tip. I actually bought two different small tips for my Hakko that are for SMT, some very thin solder, and a flux pen. I should be fine.

Bo Deadly · Mar 16, 2021

I actually prefer surface mount for low voltage non-signal paths. And even for signals it will work fine. For a lot of stuff like analog gates and such you don't have any choice and the choices are only going to get more limited to smd. I like smaller. It makes for more compact boards. I have no problem with 0.5mm pitch stuff like a VSSOP package. But for that size I don't try to solder individual pins. I just do them all at once, wick off the excess solder with some braid and then clean off flux with 99% isopropyl.

Ricardus · Mar 16, 2021

I did a solder.

Bo Deadly · Mar 17, 2021

I'm sure that will work just fine but you could get away with a lot less solder. I use a flux pen to get flux on the pads, place the part, put a *tiny* amount of solder on the iron and then roll the tip into the edge of one of the legs while holding the part in place with some tweezers. When that little bit of solder on the tip touches the joint between the leg and it's pad, the flux combined with capillary action sucks the solder into the joint. Once I've done two legs that way, I slide the tip instead because the part should be fixed in place and it can withstand a little bump. I need a magnifying lamp to see all of this though.