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Prototyping with TDFN Package IC`s

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StudentSA

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Hi,

I do not have a Hot air/Reflow station and I do not make PCBs at all but an IC that I want to use only comes in a 6 pin TDFN package. I have found that a lot of IC`s are not being made in DIP packages anymore.

What is the best way to use this IC? Shall I attempt to solder wires onto the contacts? or do you get a PCB converter that you can plug these things in and have access to solder pads/pins.

Thanks,
StudentSA
 
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I use Weller portaso PSI-100K, or Master Appliance Ultratorch UT-100 butane soldering irons with hot gas attachment.

These work better then hot air soldering irons. The hot gas is hotter with less air flow to move parts around.
 
I use a gas soldering iron with a hot air tip for DFN's. You'll be surprised at how surface tension becomes your friend, as the chip magically corrects itself and moves into perfect position!

As for TDFN, off the top of my head isn't that 0.5mm pitch? yikes... I haven't seen a TDFN PCB adapter, although I'm sure they do exist somewhere. Perhaps look for a SOT23-6 adapter? Not the same pitch, but they are widely available and perhaps with a little modification of cutting the pads length, it would fit. SC70 might be closer, but I haven't seen adapters for those.
 
One rather desperate method I use for dual pin SMT packages (not quads) is to cut lines into raw copper clad. As they are all straight its pretty easy to score, and then use something a bit wider to create a thin 'etched' channel. I've only ever used a plastic ruler and a blunt craft knife - which is actually better than a sharp one. Your package has 6 pads, and a centre pad. Thats only two lines to be cut either side, (separating pins 1 and 2, and 2 and 3). Then two horizontal lines to isolate the centre pad.

I believe maxim had an app note about this, but they used a dremel. Handy for lots of cutting, but difficult to get straight, a knife seems to work wonders.

One on a PCB, you'll have long thin traces of copper to solder wires to, without soldering directly to the chip - and no ferric chloride in sight. :)
 
I just tried to prototype a TDFN 14pin IC by soldering thin copper core wires from some transformers. This is a 0.4mm pitch and i took a whole day to get it done and troubleshooting yet to be done.

I don't think i can cut lines on copper clad that close together. Seriously needs a DFN or QFN to DIP converter at 0.4mm. I need to solder about 10+ pieces for my hobby project.

Any tips or suggestions?
 
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As suggested, you *can* get TQFP adapters, although these are of course ''quad' as opposed to dual, you can cut one in half, and glue them together on a blank substrate, essentially bringing two sides closer together. As far as I am aware, these are the only 0.4mm adapters available, at least here in the UK.

Another google revealed this for the OP:
Proto Advantage - DFN-6 to DIP-6 SMT Adapter (0.4 mm pitch, 1.2 x 1.0 mm body)

As for TDFN14, given the number of pins each side, I'm afraid I don't see a way of using standard 0.5mm pitch adapters (which will work for < 4 pins each side, up to TDFN8). All I have found are QFN 28 0.4mm pitch. Unfortunately, the centre pad is 2.4x2.4mm < - this seems to be the exact distance between pads on the underside of a TDFN14.

Tough one eh? I've only managed to make 0.5mm pitch footprints PCB's (up to TQFP144) with press-n-peel, 0.4mm, although the 0.1mm difference, I fear wouldn't be easy.

A final last ditch option, would be to find a PCB with a TDFN14 device on it, and replace it with your chip = not good for more than one. At least it would likely break out the pins to larger pads to other components.

Just had yet another idea lol, this one *might* be more practical. You can get FFC flex cables in 0.4mm pitch, many are made from polyamide, which can withstand soldering temps. This means you have a flexiable 'PCB' with tinned 0.4mm pads on each side. Sockets are also available for them, which have dual 0.8mm pins either sides. Again, this is ridiculous amount of work, sounds like you might as well just get the PCB adapters made up. Sparkfun are pretty cheap for small adapter boards in quantities 10+
 
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You can solder narrow pitched IC-pins with a normal iron.

Fix two diagonal pins with little solder tin first.

Then solder one entire line of pads after applying flux which will cause shorts between all pins. Thereafter use lots of flux and wipe along with the iron towards the traces.

If you applied too much solder tin use copper braid (good quality) and remove excessive tinning.

Boncuk
 
You can solder narrow pitched IC-pins with a normal iron.

Fix two diagonal pins with little solder tin first.

Then solder one entire line of pads after applying flux which will cause shorts between all pins. Thereafter use lots of flux and wipe along with the iron towards the traces.

If you applied too much solder tin use copper braid (good quality) and remove excessive tinning.

Boncuk

yep that what i do also, once you had tried it it is not so hard to do.
 
What i do is to tin the pins and the wire first, and then lay the wire resting on the pin with the help of a microscope. Then using my butane torch i just sweep over and its done.

I do it one at a time.
 
I believe the OP and another poster asked about finding adapters for TDFN, not how to solder them per se. So far the only real option I have found is designing custom adapter boards, and getting a cheap board house to make them up. Its all well and good explaining how to solder them, but thats the next hurdle, he/she requires something to solder them too
 
Good man!

The real advantage of getting SMT adapters made up is, you generally require more than one of them. For one-off designs even the cheapest board houses are expensive, but if you make a double sided adapter, for say, MSOP8 and TDFN8, they're so small, it works out to be very cheap indeed.
 
I believe the OP and another poster asked about finding adapters for TDFN, not how to solder them per se.

Objections!

The question was how to handle those chips when placing them on a PCB.

Quote: "What is the best way to use this IC?" (First and original post)

I guess giving hints how to solder parts like that is not off thread.

Boncuk
 
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