Connecting boards with pin headers - mechanical strength?

[dfuruta]

Hello,

Apologies in advance for the possibly naive question - I've searched but haven't found anything specific.

I'm starting to design a project that will have a main board and a number of child boards, which will be attached perpendicularly to the main board.  The boards will not need to be unplugged/re-plugged frequently once built.  Using right angle pin headers on the child boards and sockets on the main board would be a cheap & easy way to connect them.  Will this likely be good enough as mechanical support for the child boards?  The child boards will be reasonably small and light.

I've seen quite a few examples that use pin headers for connection where the boards are parallel - arduinos, for example - but I can't think of seeing ones where they're perpendicular.  Maybe it's common and I just don't get out enough...

Thanks in advance for any tips!

 

[joaquins]

Something like that?

If I could I'd use doble row pin headers as they will hold much better, but if the child board is really light and doesn't have much length away from the pin headers should do. I wouldn't use this in a circuit exposed to vibration, like on a car but for a studio mixer should be safe enough.

JS

 

[PRR]

Card-edge connectors, such as used in PC card-slots, are much better support and avoid a fiddly solder on the card (you do need a pattern for the card-edge fingers, and the motherboard connector may be fiddly.)

Mechanically you REALLY want another support. PCs have the screw in the top-back of the card. Card-cages had a notched bar which grabbed the tops of the cards and braced them to the chassis.

 

[dfuruta]

Thanks for the tips!  I should have stated in my original post that I don't need very many pins;  5 would be enough, 8 would be plenty.  There are also going to be quite a few of the smaller boards - up to 20 per main board.  So, I'd like to keep the cost of the connectors as low as I can.

Joaquins, that was what I was thinking, but my boards are going to be somewhat larger than that.  Each will have a couple of through-hole opamps with associated circuitry.  The more I think about it, the less I think that headers alone are going to be strong enough to hold them up.

Wonder if my cheapest decent option might be to use pin headers for the electrical connections with small L brackets connecting the boards for mechanical support.  It's not the prettiest looking solution, but it seems like it would work (?).

 

[zamproject]

why not soldering? if you don't plan to unplug your daughter board.
Zam

 

[JohnRoberts]

I did one packaging project back while i worked at Peavey where I had to accommodate a bunch of front panel controls, rear panel I/O, and lots of internal trims.  I ended up with a vertical mother board holding the front panel controls, and multiple daughter boards plugging into the front mother board at right angles. The product was a 4TR tape recorder so each channel had it's own daughter board. To accommodate all the trims, the daughter boards were at a 30' angle wrt vertical, so I could put the trims along the top edge and access them from the top with the cover removed, for set up while the unit was all together and working (tape recorders had way too many trims).

For robustness I used something like 40 mil square pins, pressed into the mother board (we had a machine for that at Peavey) and the mating female connectors on the daughter boards. These connectors were on something like 0.156" centers and were very robust, and made nice high current, low impedance connections.  I suspect you could use headers in place of the machine inserted pins.

The daughter boards had two 1/4" audio connectors each mounted to the rear panel metal so were well supported mechanically in the back by the jacks, and front by header connectors.  The factory guys though i was a little crazy because of the weird angles, but being able to squeeze it all in with good access to all the trims worked. 

JR

PS the product was still a royal PIA to build. It took my technicians a few hours for each deck in production to dial in all the trims (In addition to tape bias and all it had Dolby NR which required playback level calibration). :-(

 

[dfuruta]

Even if I do solder, I still need pins and some kind of mechanical support.  I don't like to trust solder for mechanical strength...

why not soldering? if you don't plan to unplug your daughter board.
Zam

JR:  yikes!  that sounds like quite a box.  Always been impressed by how intricate the mechanical construction can be on "prosumer" audio equipment.

 

[JohnRoberts]

Even if I do solder, I still need pins and some kind of mechanical support.  I don't like to trust solder for mechanical strength...

+1.. In general solder connections remain somewhat plastic so if mechanically stressed can degrade. BUT, if there are enough pins in a connector there may be enough mechanical support to not degrade.

JR

 

[shabtek]

Poctop  has fabbed some mic pcbs where  the tube socket is mounted on a  daughter card that tongue and grooves into the main pcb for primary mechanical strength and has solder fillet for  mechanical and electric connection. This seems a durable solution.

 

[pvision]

Mount the motherboard horizontally and plug the daughters in vertically?  That should get round most of the problems

Nick Froome

 

[zamproject]

Even if I do solder, I still need pins and some kind of mechanical support.  I don't like to trust solder for mechanical strength...

+1.. In general solder connections remain somewhat plastic so if mechanically stressed can degrade. BUT, if there are enough pins in a connector there may be enough mechanical support to not degrade.

JR

Yes you both have right, the example I have in mind when saying that is the small DOA loaded in my desk.
Zam