SMD soldering... Not as hard as it looks!

[tsteele93]

I've been working on some drivers, like laserluke's buck driver, which uses a very tough Surface Mount IC.

It looks daunting.

But this video is amazing and really helped me have the confidence to do some very small scale soldering.

 

[jcranmer]

No way! All I saw was someone performing black magic.

 

[foulmist]

these ICs are easy. but if you have ICs with pads on the bottom side of the IC you won't be able to use just the soldering iron. You'll need a hotair or infrared rework station. Or oven. Nice video btw, Tom :beer:

Thanks for sharing :beer:

 

[tsteele93]

That video definitely made me think that I can try some smaller stuff.

I actually have an old stereo microscope my father-in-law gave me that I can use. I hadn't thought of that. I had just been using a magnifying station.

I was afraid hot air might move the ic around. I baked a couple in a small but powerful toaster oven that I picked up for $3.50 USD at a Goodwill Store. It worked well on everything except the TPS IC's turned cockeyed on me.

 

[foulmist]

That video definitely made me think that I can try some smaller stuff.

I actually have an old stereo microscope my father-in-law gave me that I can use. I hadn't thought of that. I had just been using a magnifying station.

I was afraid hot air might move the ic around. I baked a couple in a small but powerful toaster oven that I picked up for $3.50 USD at a Goodwill Store. It worked well on everything except the TPS IC's turned cockeyed on me.

You sure need a temperature control. Sometimes even 200C is too much for some stuff. On smaller and thinner boards like mine (16mm) I even use 180C and the solder melts perfectly. I have had boards going expanded due to excessive heat at 230C.

 

[tsteele93]

Well, I am using a Kester paste that is low temp and I could actually see it melting across the board, so I was not heating past the melt point for very long at all. I do have an infra red thermometer I can use, but it doesn't work well through the glass, so you gotta open the door to check. So it isn't the best. I should get a nice in-oven thermometer.

I don't think I was much over 400F though and these are dorkbot PCBs, they seem fairly thick.

 

[foulmist]

That temp control inside the oven would definitely bring some light to the darkness. And you won't have to worry about excessive heat and worrying about it every minute.

 

[lazeerer]

Here is a better video by the same guy.:

Its more accurate to what you are doing.

 

[foulmist]

excellent video! very nice tutorial for all!

 

[lazeerer]

Yeah it is a Good Video but its nothing like actually doing it but it helps to watch it.

My boost driver is using a MFL12 "Pads on the Bottom" Just like your Driver but a different package and I can tell you its very hard.

Even now. I still get fails. Though the fails are not as the driver is Toast and you have toss it but fails as you need to rework it.

90% of the time you yourself will kill the driver with to much heat in the rework if you do get a fail.

The fails you get is either a short where you added to much solder and pads bridge or the other fails you will get is you dint put enough solder and all the pins dint re flow.

Its Just very Hard to do and very time consuming. It still takes me a good amount of time to do it.

Re-flowing these type of chips are a totally different ball game..

Though its fun and i like doing it so its why i continue.

 

[foulmist]

I know man,

I have been doing this for 5 years now. Repairing mobile phones and such. These ICs are relatively small and I am pretty confident in doing them.

I still have problems with the big processors which have hundreds of dots on the bottom. Sometimes I can't get them in the first try

It's all about experience and consistency. :beer:

 

[lazeerer]

Well you have way more experience then i do with these style QFN/MLF style ICs.

Ive been doing it for ~ 1 year these specific IC and I would say i have to rework at least 20% of them If not more.:shhh:

Best thing i learned is Dont rush. Take as much time as you need. I made the mistake many times when i first started with these Kind of IC and Always put to much paste.

I think Hot air works the best though. THe Re flow oven your limited to what you can do like you cant push the chip around so it can pop into place. Stuff like that.

I think i bought 10 chips for my boost drive when i first started. Only 2 drivers worked after i did them.:crackup:

Now I have gotten good at it to where 8-9 of the driver work perfect and 1-2 needs the re work.:beer:

 

[532 with Envy]

Learn something new everyday!

Nice like to the video....thanks.:beer:

 

[foulmist]

Well you have way more experience then i do with these style QFN/MLF style ICs.

Ive been doing it for ~ 1 year these specific IC and I would say i have to rework at least 20% of them If not more.:shhh:

Best thing i learned is Dont rush. Take as much time as you need. I made the mistake many times when i first started with these Kind of IC and Always put to much paste.

I think Hot air works the best though. THe Re flow oven your limited to what you can do like you cant push the chip around so it can pop into place. Stuff like that.

I think i bought 10 chips for my boost drive when i first started. Only 2 drivers worked after i did them.:crackup:

Now I have gotten good at it to where 8-9 of the driver work perfect and 1-2 needs the re work.:beer:

yeah man hot air station gives you more control over the process than the oven. As you said you can push things around :beer: keep it up I am sure you will get at least 100% success on your boards soon :beer:

 

[tsteele93]

Here is a better video by the same guy.:

Its more accurate to what you are doing.

Good stuff! I need one of those board holders with the heater under it!

Thanks!

 

[tsteele93]

This looks nice. Anyone have any suggestions for better tools. I'd like one of those heaters to go under the pcb to get it to 150.

HOT AIR GUN HOLDER WITH FIXTURES FOR SMD REWORK SOLDERING STATION | eBay