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frankus 4 days ago

For just straight up assembly of one-sided SMT boards (i.e. not reclaiming components from a donor board), a $30 plug-in electric skillet and a solder paste stencil from the PCB manufacturer (or patience and a solder paste syringe) works far better than it has any right to. https://www.instructables.com/Simple-Skillet-Surface-mount-S...

Aurornis 4 days ago | parent | next [-]

The hot air station is called a "rework station" because it's very helpful for rework, too.

Using a hot plate to reflow boards is fine if you already know everything is correct. Having a real hot air station is very important if you need to change any parts or even fix reflow problems.

throw-qqqqq 4 days ago | parent [-]

I prefer a regular soldering iron for SMD. Below 0603 I tend to blow off unrelated components if I’m not very very careful!

So for me, a loupe/microscope and a fine SMD iron is the best option. I have some China-model that uses Hakko tips.

junon 4 days ago | parent | next [-]

Kapton tape is your friend for hot air. It's cheap and you can get by with scissors.

Tape out anything that you're not reworking, use tweezers and push down the edges against the board to seal as best you can, and then flux it and blow.

It'll hold things in place and wick away the heat from anything you're not trying to rework. I went from a near 0% success rate to near 100% with it.

throw-qqqqq 4 days ago | parent [-]

Wow, thanks for the tip! I never heard that one before.

I have a hot air station that I haven’t used much because I found it difficult to control. I will give it another try but with the Kapton!

jdietrich 4 days ago | parent [-]

To protect larger areas, you can use aluminium foil. It's usually best to hold the hot air pencil at a right-angle to the board; if you angle it like a soldering iron, the excess heat all goes in one direction and you're much more likely to blow off small adjacent components.

alnwlsn 4 days ago | parent | prev | next [-]

Nobody believes me when I say that soldering SMD with an iron is easier than through hole. You don't have to keep flipping the board over!

throw-qqqqq 4 days ago | parent | next [-]

To be fair, it takes a little practice IMO and until you learn how to use flux correctly etc., it can seem very unattainable to ever learn well.

I got a huge confidence boost from one of the old engineers with rubbish eyesight. Thinking “If HE can see well enough to do 0603 and smaller, then so can I!” :D

A few hours practice on scrapped electronics made a big difference for me.

jacquesm 3 days ago | parent | prev [-]

You don't have to 'keep flipping the board over' when doing through hole either. Just stick all of the components in, fold over two legs on chips and passives, then solder all of them in one go.

oasisaimlessly 4 days ago | parent | prev [-]

If you're blowing off stuff, your pressure setting is too high. I usually start at the lowest setting, and only go up if I need to deliver a lot of heat to an area.

antoniuschan99 4 days ago | parent | prev | next [-]

I been using these mini pan frying skillets for years for prototype boards. <$2. An IR thermometer with a laser is handy during the process.

https://www.aliexpress.com/item/1005008863940082.html

And here is the cheap hot air rework station I use. <$15

https://www.aliexpress.com/item/1005005989227215.html

You can even opt out of the stencil but I never do cuz it's much easier than not having it.

stn8188 4 days ago | parent [-]

Haha I've got an old toaster oven, it works wonders for basic prototype assembly!

brokenmachine 3 days ago | parent | prev [-]

On aliexpress, search for "demolition heating" and there are really cheap ($5 or so?) heating plates that I believe are used for removing SMD LEDs.

Not sure why they'd need to remove SMD LEDs, but whatever.

They are "PTC" which means they top out at a certain temperature, usually 260 degrees.

I would recommend using an inline fuse holder for some semblance of safety though.

One of these, a lamp cord, some solder paste and a toothpick, and you can easily assemble SMD boards.