Most QFN packages have solder-surfaces on underside, and on the edges, so you get a visual-inspect solder fillet. For manual assembly, it can help to extend the PCB solder pads a little. QFN packages also usually require the centre GND area, is soldered, and I think that is a stress cycling issue.
$begingroup$I am not very experienced with soldering. I have a basic soldering iron with a new tip, and a third hand.
Last time I tried soldering wires to a ble chip that looked like this, I ruined two chips in the process and gave up. Those were not cheap.
Now I want to solder this QFN chip but I want to have the right tools and skills for the job.
Perhaps I don't even need to solder, all I want is to connect some of the pins of the chip to a bread board. If there is another way to do that without soldering, I would prefer that.
I am a novice in this area. Any help, guidelines or reference to tutorials for beginners would be much appreciated.
I just want to know what is the best way, that is relatively safe (so I won't destroy the chip), to get it on a bread board.
Thanks!
rosewaterrosewater
$endgroup$4 Answers
$begingroup$I would suggest to buy a QFN to DIP adapter, something like this.
Then, you can use air reflow or solder with an iron. I solder all 0.5mm pitch components, such as CPLDs or FPGAs with a good soldering iron using a small (thin) tip.
However, it might not fit well into your breadboard since there are two parallel rows on each side. What I usually do is solder DIP female pin headers
on this board and then use wires to connect it to the bread brad.
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$endgroup$$begingroup$Short answer: You can't with your equipment.
That's a .5 mm (20 mil) QFN. Trying to solder that with a soldering iron will only make a mess. Ideally you use solder paste, a stencil, accurate automated placement, and a reflow oven.
I have soldered similar chips with a hot air station and some care. Use a soldering iron to put a bead of solder on all the pads. You want the amount of solder on each pad to be as even as possible, but there should be a clear 'bulge' of solder on each pad.
Then liberally apply paste flux and very carefully place the chip correctly over the pads. Use a magifying light or similar to make sure the chip is aligned close to right. It doesn't have to be exact, but you don't want any part of a pin over a adjacent pad. This step is tricky, especially since it's hard to move the chip the tiny amounts required for final alignment.
Next apply hot air. I usually use around 700°F, but only the minimum air flow you need. Try to heat the chip as evenly as possible. After a few seconds, you will see the solder melt, at least on one side, then hopefully all sides a second or two later. At that point the surface tension of the molten solder will align the chip nicely. You will probably see it move. Leave heat on for another few seconds just to make sure everything is really melted, then remove heat and let cool. This whole step should take maybe 10 seconds, 20 tops.
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$endgroup$$begingroup$The CC3200 is available as a module too, with integrated crystal and all the support components. I highly, highly recommend that you use that. It's not easier to solder, but it will have a booster pack available which you can just plug into your main PCBA.
Or even easier, just buy the CC3200 Launchpad and use it for the basis of your product.
Fix It Until It's BrokenFix It Until It's Broken
$endgroup$$begingroup$Check out this product from Schmartboard. It is a special breakout board made for your specific IC package, and all it takes is a fine-tipped soldering iron to make the connections.
Basically, it has troughs preloaded with solder. You place the chip, and then (with the soldering iron) you push the solder towards the IC, where it makes contact to the pads underneath.
I've used them before, and it's a little tricky at first. Expect to throw away the first IC you try, although you may not actually have to :)
However, as @MattYoung said in a comment, trying to get rf working through wires and a breadboard is bound to be frustrating.
Good luck!
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