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Topic: low cost, low profile female headers? (Read 2020 times) previous topic - next topic

PeterPan321

I have a number of PCBs for my own application (shield I guess) which I need to populate with NANO boards. I would like to be able to remove them someday, and so I've bought some female breakaway headers (usually 40 pin). All of those female headers I've found though add more height to the overall board thanh I'd hoped for. I have found a few better sources of LOW PROFILE female headers from major companies like 3M, but they cost an awful lot. I've also found reasonably priced low profile headers, but most of those require round pins, so they won't fit the pins supplied with NANOs.

So, I guess my choices are:

1) Find some low profile female headers good for square pins that don't cost an arm and a leg
2)1) Get round pin replacements for the NANOs along with the low profile round femal3 headers.

Any product pointers appreciated.

OH... I had tried some low profile large IC sockets, but they are made for much thinner pins, and no reasonable pressure will get a NANO with its "stock" pins into those sockets.


pert

I don't think there's any way for female headers that work with the standard square male headers on your Nano to be much more low profile because you're limited by the length of the male pins. You can get Nano clones without the headers soldered. The Pro Mini also comes without headers soldered and that board could be a good choice to use on a finished project where you aren't frequently uploading sketches.

qwertyAT

What do you consider expensive / cheap?

Wouldn't the male header still be to long, even if you find small and inexpensive female header?

maybe just buy longer female headers to gain some extra space to your shield?

PeterPan321

I don't think there's any way for female headers that work with the standard square male headers on your Nano to be much more low profile because you're limited by the length of the male pins. You can get Nano clones without the headers soldered. The Pro Mini also comes without headers soldered and that board could be a good choice to use on a finished project where you aren't frequently uploading sketches.
Well I seem to have accumulated single row breakaway pins in quite a few lengths over the years. But even if I used the ones that came with the NANOs ready to solder in, one end is usually longer than the other, so I guess its possible to carefully solder in through the opposite direction. But its a good point.

PeterPan321

What do you consider expensive / cheap?

Wouldn't the male header still be to long, even if you find small and inexpensive female header?

maybe just buy longer female headers to gain some extra space to your shield?
Well longer femal headres do seem to be dirt cheap. Last buy on ebay got me ten 40pin female headers, for about $4.50USD. shipping included. Those stand off the PCB about 0.330", or 8.4MM. 

On the other hand, no such luck on anything low profile, unless I go to a more standard distributor, lie these at Mouser.com...

https://www.mouser.com/ProductDetail/3M-Electronic-Solutions-Division/929870-01-16-RA?qs=%2fha2pyFadujRJI8DsGJUZWlaYrgHz%2fuPzohApSC1ewKo2kmrfa%2fcIQ%3d%3d

Those stand off the board about 0.148", or 3.72MM. Quite a difference. But, 10 of those, and only 16 position, would cost $18.60 USD. 

So I guess I'm looking for something a little more comparable in price to the higher sanding ones.

pert

You can get the round pin headers on eBay. They're a little more expensive than the square pin ones but still not too bad

PeterPan321

I don't think there's any way for female headers that work with the standard square male headers on your Nano to be much more low profile because you're limited by the length of the male pins. You can get Nano clones without the headers soldered. The Pro Mini also comes without headers soldered and that board could be a good choice to use on a finished project where you aren't frequently uploading sketches.
I probably should have mentioned that many of my NANOs are clones, and I had gotten so used to soldering on header pins myself, I forgot the fact that the non-clones usually come pre-soldered.

DrAzzy

#7
Jun 19, 2018, 10:14 pm Last Edit: Jun 19, 2018, 10:15 pm by DrAzzy
I think the best course of action is what Pert suggested - nano or pro mini clone without pre-soldered connectors, and solder on round pin header. That gives you a gap of ~0.2" between the boards.

You can also solder a pro mini (but not a nano, since there's stuff on the underside) directly onto your circuit board - put holes matching the pro mini footprint on your PCB, and solder it down.  Making the connections can be tricky, but it's not that bad. I position the board, put no-clean gel flux on the holes, and then solder them - when the solder finally wets the metal around the hole in the PCB you're soldering it down to, you'll see the solder suddenly appear to get sucked in - that's what you're going for. Also inspect the board from the bottom to make sure you see solder on the underside of all holes. I've used this method in a number of designs, and it's now my favorite way to mount pro mini's on a larger PCB - though I would hesitate to use it where the board will be exposed to significant vibration or flexing.
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PeterPan321

I think the best course of action is what Pert suggested - nano or pro mini clone without pre-soldered connectors, and solder on round pin header. That gives you a gap of ~0.2" between the boards.

You can also solder a pro mini (but not a nano, since there's stuff on the underside) directly onto your circuit board - put holes matching the pro mini footprint on your PCB, and solder it down.  Making the connections can be tricky, but it's not that bad. I position the board, put no-clean gel flux on the holes, and then solder them - when the solder finally wets the metal around the hole in the PCB you're soldering it down to, you'll see the solder suddenly appear to get sucked in - that's what you're going for. Also inspect the board from the bottom to make sure you see solder on the underside of all holes. I've used this method in a number of designs, and it's now my favorite way to mount pro mini's on a larger PCB - though I would hesitate to use it where the board will be exposed to significant vibration or flexing.
I think if this (or another) project becomes so definitively "done" (meaning no more PCB revisions likely ever), I might do something like that. In fact most of the China based PCB fab houses I've worked with don't charge any noticeable amount more to cut rectangles or slots into your boards. So I guess I could make a rectangle just slightly smaller than the NANO, so I could place it flush without the USB chip and other bottom components hitting the board, and solder edgewise like you're suggesting.

But this current project is still a little "early" for me to make a permanent attachment. So if I can find some female headers a little lower, without costing 20X more, I'd buy some.

Riva

Are you thinking about something like this...
Don't PM me for help as I will ignore it.

PeterPan321

Are you thinking about something like this...

Yes, but without the staggered leads. More like this...

https://www.mouser.com/ProductDetail/3M-Electronic-Solutions-Division/929870-01-16-RA?qs=%2fha2pyFadujRJI8DsGJUZWlaYrgHz%2fuPzohApSC1ewKo2kmrfa%2fcIQ%3d%3d

PeterPan321

You can get the round pin headers on eBay. They're a little more expensive than the square pin ones but still not too bad
Yeah... that does seem like the best Idea. They are very short (the pins_, and so the sockets for them are low profile too. I image they will be a little loose when I solder them to a NANO clone, but that's easy to remedy by soldering in the sockets first, inserting the round pin headers, adding the NANO and soldering last.

Good tip. Thanks!

Riva

Yes, but without the staggered leads. More like this...

https://www.mouser.com/ProductDetail/3M-Electronic-Solutions-Division/929870-01-16-RA?qs=%2fha2pyFadujRJI8DsGJUZWlaYrgHz%2fuPzohApSC1ewKo2kmrfa%2fcIQ%3d%3d

If you look closely at the connectors I posted you will see the pin holes go all the way through the connector so as long as you have corresponding holes in the PCB you can plug from either side or allow the long male pins to sit through the PCB.
Don't PM me for help as I will ignore it.

ChrisTenone

Just curious, is there any problem with clipping off the male pins so they are shorter? (Cause I have done this where a board (Adafruit Trinket MO) stuck up too far for the enclosure lid.)
What, I need to say something else too?

PeterPan321

If you look closely at the connectors I posted you will see the pin holes go all the way through the connector so as long as you have corresponding holes in the PCB you can plug from either side or allow the long male pins to sit through the PCB.
Yep I see that. Appreciate the close up photo! I Do use those kinds of connectors when I cut my own one sided boards for simple circuits, and don't want to be bothered drilling holes. For boards I send off the a fab house though, I do my best to avoid what I'd call "specialty" parts. It can lock me into one or two exclusive suppliers, and end up costing more in the long run. I think I may go with the the round pin headers and sockets @Pert recommended.

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