Author Topic: stacking PCBs, wire connection ideas?  (Read 1866 times)

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Offline AdminTopic starter

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stacking PCBs, wire connection ideas?
« on: January 18, 2009, 07:51:54 AM »
I am considering designing two PCBs that are stackable.

Both PCBs are about 1.5" squared, and with soldered on components no more than about 5mm thick.

The problem I have is that I'd like both PCBs to share at least 11 connections. The connections need to be non-permanent, meaning I can disconnect both boards within seconds (so I can't just solder on 11 wires). Also much be under $20 each.

Anyone with ideas?

Perhaps 2 or 3 micro ribbon cable connectors?

Another idea I can find is this below. My complain about it though is that the spacing is too much - I want no more than ~7mm spacing if at all possible:
http://www.sparkfun.com/commerce/product_info.php?products_id=8454


Offline HDL_CinC_Dragon

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Re: stacking PCBs, wire connection ideas?
« Reply #1 on: January 18, 2009, 07:57:53 AM »
There are cell phones that use metal contact plates to let the component PCBs to talk to each other with clearance around 2mm of eachother. One PCB/Device typically has just a flat solder surface like what you would expect an SMD to mount to while the other either has solid raised bumps or metal flexible tongues. Perhaps thats something you can look into? The ZIF advantage is pretty attractive with that design too.

-EDIT-
I apologize for the crappy post. I stayed up all night working on a program.

-EDIT-
Fixed some crappiness
« Last Edit: January 18, 2009, 08:03:52 AM by HDL_CinC_Dragon »
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Re: stacking PCBs, wire connection ideas?
« Reply #2 on: January 18, 2009, 09:29:07 AM »
I just found this at sparkfun (below image), perhaps 2 of these will work:
http://www.sparkfun.com/commerce/product_info.php?products_id=574

and some ZIF connectors I'll look at . . .
http://www.mouser.com/Search/Refine.aspx?N=1753272+4294635132+4294635141+4294635146+4294741847+4294741457+1323043&Keyword=molex&FS=True

but haven't decided what to use yet . . . still looking for cables, too . . . or better yet, the top board could just snap into the bottom board without a cable would be even nicer . . .


Offline HDL_CinC_Dragon

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Re: stacking PCBs, wire connection ideas?
« Reply #3 on: January 18, 2009, 10:07:27 AM »
I just found this at sparkfun (below image), perhaps 2 of these will work:
http://www.sparkfun.com/commerce/product_info.php?products_id=574

Those look like they would work pretty well if you have them both sideways laying down on their PCBs.


and some ZIF connectors I'll look at . . .
http://www.mouser.com/Search/Refine.aspx?N=1753272+4294635132+4294635141+4294635146+4294741847+4294741457+1323043&Keyword=molex&FS=True

If I'm IDing them correctly I've seen those used in CD drives and scanners and many other such devices and they work really well and are very very low profile.

but haven't decided what to use yet . . . still looking for cables, too . . . or better yet, the top board could just snap into the bottom board without a cable would be even nicer . . .

The idea about using contact plates would be the best option for this one. Wouldnt even need to snap it into the bottom if you didnt want to. I suppose you could use a plastic catch sort of thing that I cant think of the name for. Often found as cheap motherboard mounts instead of using all screws to hold the mobo in place.
Found a pic of them. Google triumphs once again.

(Click for bigger if needed)
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Offline Soeren

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Re: stacking PCBs, wire connection ideas?
« Reply #4 on: January 18, 2009, 04:27:57 PM »
Hi,

In a (very) former job, we used some connectors which were soldered to only one board, while the other had through-plated holes (gold plated) for grabbing the connectors that were split end and springy, sitting on a "bar" of the snap-off kind for easy mounting. They were very rugged and the hand held terminals they were used in saw tough abuse, but the connectors held up. Unfortunately, I don't know if they are made these days.

Different types and pitches can be found numerous places though, a couple of links follow:

GradConn
http://www.gradconn.com/index.asp?src=CPCB2B

Hirose
http://www.hirose-connectors.com/connectors-productcategory/boardtoboardconnectors.htm
Regards,
Søren

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Offline krich

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Re: stacking PCBs, wire connection ideas?
« Reply #5 on: January 18, 2009, 06:03:07 PM »
I did a board stacking design for my prototype boards and it's working great.  I had a similar requirement in that I needed 9 connections between boards.  But I did have one additional requirement, and that each board should be able to be further stacked upon.  Don't know if you need that, but here's the tutorial I wrote about what I came up with:

A Modular PCB Layout

I got the connectors from Samtec.  They've got everything, so I'm sure you'll find what you need if you dig around there a bit.  They sent me some samples so that I could be sure it was right.  Quick shipping, no hassles.  Good folks.

Offline bukowski

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Re: stacking PCBs, wire connection ideas?
« Reply #6 on: January 19, 2009, 03:10:18 PM »
I was messing around with eagle and I made a couple of mating cards with the intention of using a card edge connector (kind of like a PCI bus uses), but for the life of me I couldnt find a simple one for just stacking the cards. Im still looking tho, if anyone knows what I am talking about and has any ideas, hit me up. It seems like something like that would be perfect for your app too.

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Re: stacking PCBs, wire connection ideas?
« Reply #7 on: January 28, 2009, 05:46:35 AM »
But I did have one additional requirement, and that each board should be able to be further stacked upon.  Don't know if you need that, but here's the tutorial I wrote about what I came up with:

A Modular PCB Layout

Yeap I have that requirement. Do you know of connectors with much smaller spacing, but does the same thing? My device is for microrobots.

I ended up thinking outside the box a little . . . I decided I was better off adding a microcontroller that gathered data from all ~12 signal lines and output the processed data through UART (3 wires). Although more complicated and takes up more space, it has many other benefits to my particular design. Price-wise the microcontroller was cheaper than the connectors!

Offline Ro-Bot-X

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Re: stacking PCBs, wire connection ideas?
« Reply #8 on: January 28, 2009, 06:57:06 AM »
Check out the uBotino robot controller!

 


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