Does anyone LIKE soldering SMDs?

C

comradehoser

Well-known member
After back-to-back failures originating with my SMD soldering (I load flux on the pads, load solder on the pads, flux on the smd legs, place on pads, touch with iron technique), I am wondering if anyone actually enjoys soldering them, particularly JFETs and transistors--those squirrely little needle-tweezer damanding grains of rice. I've destroyed two, lost one, but always it seems like they never sit right and cause issues with my builds.

They hurt my eyes, tax my nerves and fine motor skills, and give me agita.
 
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I don't mind them but my eyesight is rapidly declining, so my opinion might change.

Transistors are probably the most finnicky to work with since they don't have much area to grab onto and have to be oriented a particular way.

Not sure if this is how you're doing it or not, but I only add solder to one pad, hold the transistor in place, then heat the tinned pad. Adding solder to more than one pad makes the part sit unlevel. (Obviously solder the other pads afterwards)
 
I bought a cheap amazon hot air rework station and a syringe of solder paste. I haven't used it that many times, but when it works right it is kinda enjoyable. The small parts still suck and you can blow your transistors away if the air is up too high, but watching all the pins on an IC flow out at the same time is pretty cool.
 
Erik S said:
I bought a cheap amazon hot air rework station and a syringe of solder paste. I haven't used it that many times, but when it works right it is kinda enjoyable. The small parts still suck and you can blow your transistors away if the air is up too high, but watching all the pins on an IC flow out at the same time is pretty cool.
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A rework station is definitely on my list. I use a chopstick to hold the little buggers down, way too many of them have gone flying when my tweezers twitched a little. :ROFLMAO:
 
I almost forgot my "secret weapon" .... super fine solder.

I'm not sure what diameter or brand this solder is... but man, it really makes SMD work easier.

I bought this roll from a factory that was shutting down about 10 years ago, I have used it on almost every FV-1 IC I've ever hand soldered (thousands), yet I've barely put a dent in it. Fairly sure this one will outlive me.

This one item had a greater impact on my workflow than any piece of equipment.

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For perspective, up against standard Kester 0.8mm.
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I use a hot plate to do all the SMT stuff at once. Solder paste on the pads with a toothpick. Stick the parts to the paste. Put the board on the hot plate until the solder all flows. Done. I made some videos of doing this with a TPA3118 board. The solder wicks onto the pads nicely on the hot plate. The videos are here but I don't put nearly as much effort now. I was learning when I made these. And, I stick all the components into the cold solder paste and then heat the board and it works really well. https://drive.google.com/drive/folders/1c7vxu4LnAe3-FKvkF1Uq7qmp1cuV4g7d?usp=drive_link
 
I like it well enough if my shit works after I’m done. So far I’m 100% success (not saying much since the sample size is pretty small). I have some hand shaking/nerve(?) issues that make the tweezer work a bitch, but somehow I manage to get it done. Doing 1 pad first is by far the best process I have tried both for transistors and ICs. Having a small solder tip helps too
 
I have a rework station but I never use it for soldering. I use it to remove the occasional IC, but it's primary job is goop removal.

I have a reflow oven but I can usually solder an FV-1 by hand in the time it takes to apply paste with a stencil... and there was that time it went rogue and charred a PCB.

I'd like to try a hot plate. @Paul.Ruby's method sounds like a dream, I'm going to have to give that a shot.
 
Robert said:
Not sure if this is how you're doing it or not, but I only add solder to one pad, hold the transistor in place, then heat the tinned pad. Adding solder to more than one pad makes the part sit unlevel. (Obviously solder the other pads afterwards)
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I think this was the way and I forgot and started dabbing solder on all the pads first. Facepalm.
 
Robert said:
I have a rework station but I never use it for soldering. I use it to remove the occasional IC, but it's primary job is goop removal.

I have a reflow oven but I can usually solder an FV-1 by hand in the time it takes to apply paste with a stencil... and there was that time it went rogue and charred a PCB.

I'd like to try a hot plate. @Paul.Ruby's method sounds like a dream, I'm going to have to give that a shot.
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I don't use a stencil. Smear paste on the pads, sparingly, and it wicks right onto the pads nicely in the heat. (Only suitable for boards with a solder mask, of course.) This worked really well making 10 TPA3118 boards all at once and all 10 were perfect. And works for the J177 and 2SK208R in my AMT preamp boards. Dab paste onto the pads, stick the transistors to the paste and heat. I actually don't know which way would be faster for me... Yours might be faster with a little practice. With my eyes, I have to work under a microscope, which may lend itself better to my existing method...

If you try this, the important thing is only a small amount of paste. For transistors, I do three separate dabs with the tooth pick and don't worry about too much. Plenty of space on the transistors for the solder to wick. For ICs, like TPA3118, I smear along all the pads and it wicks up nicely in the heat. My point is not be too picky applying the paste (as I was in my video above). Just smear it on. But not too much. Too much will bridge pads. Solder wick will fix bridged pads after cooling. If you do get a bridge, don't bother with it while on the hot plate. It takes a bit of practice, which creates a barrier to changing methods. I'm already good at my way and you're already good at yours.

This is my hot plate, by the way... https://www.amazon.com/gp/product/B07W1ZZH8T?psc=1
 
Robert said:
@Paul.Ruby Which hot plate and microscope are you using in those videos?

(Forgive me if you mentioned it in the video, I have no sound at the moment)
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And this is the microscope. https://www.amazon.com/gp/product/B09VPPS96M?psc=1

But, I rarely pull that off the shelf now. I have one of these cheapos on a goose neck permanently on my bench. The included little table and mount is useless. Need a much bigger goose neck to hold it up higher out of the way. https://www.amazon.com/gp/product/B00XNYXQHE?psc=1
 
comradehoser said:
After back-to-back failures originating with my SMD soldering (I load flux on the pads, load solder on the pads, flux on the smd legs, place on pads, touch with iron technique), I am wondering if anyone actually enjoys soldering them, particularly JFETs and transistors
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I greatly prefer hand soldering SO-8 opamps and 1206 resistors to their through hole counterparts, which at age 71 still don't require a magnifier in my case. I rarely use external flux, but .015 solder like what I think @Robert posted or .020 are definitely key. I've only done a few JFETs and no transistors so far, but the FETs went OK once I acclimated a little. Good tooling helps a ton, I have several soldering iron tips and a bunch of different tweezers for different components, and only use them for that particular task.
 
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I have done some and it has gone well so far. I just put a fair amount of flux and make sure my iron tip is clean and has a bit of solder on it. I drag soldered an IC recently and it went better than I expected.

I have a few sets of these boards that I have been sitting on until I get a little better at soldering and get a SMD components kit together. I’m appreciating all the input from everyone.
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I actually prefer soldering (and desoldering!) SMD parts to through hole. With the right iron (I use old Metcals), tweezers and a magnifying glass lamp or goggles, it's a piece of cake. I'm 53 btw, with the usual eyesight issues, so it's not just a young person's game.
 
DailyDovetails said:
I have done some and it has gone well so far. I just put a fair amount of flux and make sure my iron tip is clean and has a bit of solder on it. I drag soldered an IC recently and it went better than I expected.

I have a few sets of these boards that I have been sitting on until I get a little better at soldering and get a SMD components kit together. I’m appreciating all the input from everyone.
View attachment 87246
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Heh, that's the first time I've seen a set of those boards in that color! ;)
 
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