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Electronics => Electronics => Topic started by: madsci1016 on August 23, 2010, 07:41:12 PM

Title: Need: technique to connect PCBs using only a small footprint.
Post by: madsci1016 on August 23, 2010, 07:41:12 PM: Hey guys and gals.

I'm deep in design for a side project that involves 5x3cm PCBs that will lay flat, side by side and edge to edge; and i need a way to connect 8 wires between each board.

crimped on connectors on ribbon cable and 4x2 headers are too big in the Z direction (standoff off of board)

circuit board edge connectors straddle mount take up too much space on the PCB and would be difficult to design in Eagle, and they all seem to be non-stock for Digi-key.

Right now my only option seems to be Surface mount pin headers like this (http://www.sparkfun.com/commerce/product_info.php?products_id=9015) although i'm having trouble finding the female version.

Any other cool tricks you guys are aware of?
Title: Re: Need: technique to connect PCBs using only a small footprint.
Post by: voyager2 on August 23, 2010, 08:50:49 PM: How about hard-wiring them together, with some thin wire?

Or the female version of your SMD male header...
http://www.sparkfun.com/commerce/product_info.php?products_id=9429 (http://www.sparkfun.com/commerce/product_info.php?products_id=9429)
same pin spacing...
Title: Re: Need: technique to connect PCBs using only a small footprint.
Post by: madsci1016 on August 23, 2010, 09:12:40 PM: Quote from: voyager2 on August 23, 2010, 08:50:49 PM
Or the female version of your SMD male header...
http://www.sparkfun.com/commerce/product_info.php?products_id=9429 (http://www.sparkfun.com/commerce/product_info.php?products_id=9429)
same pin spacing...

Not SMD.

Thought about wire, but i'd like it more plug-able then that.
Title: Re: Need: technique to connect PCBs using only a small footprint.
Post by: voyager2 on August 24, 2010, 03:58:13 AM: Why not put it all on one 6 x 5 cm PCB
But why so small?!
Title: Re: Need: technique to connect PCBs using only a small footprint.
Post by: jka on August 24, 2010, 06:57:22 AM: Search Digikey for 209159004101116 and 109159004101116. They are 4 pins, so you need two sets per connection. Datasheets here: http://www.avx.com/prodinfo_catlist.asp?ParentID=14 (http://www.avx.com/prodinfo_catlist.asp?ParentID=14)

Haven't tried them, but it looks like it fits your needs
Title: Re: Need: technique to connect PCBs using only a small footprint.
Post by: waltr on August 24, 2010, 07:15:00 AM: Another source of connectors is Samtec.
Title: Re: Need: technique to connect PCBs using only a small footprint.
Post by: madsci1016 on August 24, 2010, 08:03:22 AM: Nice fine jka, I'll order a few to see if they work.

I have a feeling i won't be able to find an Eagle library for those, might be designing it myself.
Title: Re: Need: technique to connect PCBs using only a small footprint.
Post by: Soeren on August 24, 2010, 04:56:51 PM: Hi,

Why not go to a pitch of 0.05" (or even 0.5mm) if you need it small?

http://www.alibaba.com/showroom/1.27mm-smt-female-header.html (http://www.alibaba.com/showroom/1.27mm-smt-female-header.html)
Not quite what you want (unless you need 1000 pcs or more), but may give you some words to search for.
Title: Re: Need: technique to connect PCBs using only a small footprint.
Post by: Admin on August 28, 2010, 08:07:42 PM: What about a flexible PCB?
http://www.google.com/images?q=flexible%20pcb (http://www.google.com/images?q=flexible%20pcb)
http://leopardconsulting.com/images/pcb/pcb_20layer_rigid_flex.jpg (http://leopardconsulting.com/images/pcb/pcb_20layer_rigid_flex.jpg)

(http://image.made-in-china.com/2f0j00lMythLPKYfrD/Rigid-Flex-PCB.jpg)
(http://leopardconsulting.com/images/pcb/pcb_20layer_rigid_flex.jpg)
Title: Re: Need: technique to connect PCBs using only a small footprint.
Post by: madsci1016 on August 28, 2010, 08:57:02 PM: Thanks for the suggestions guys. One goal of my design was to be easy for others to duplicate, so I ended up sticking with regular pitch headers, and it took hours on eagle to get it all to fit, but I was able to squeeze them in.

Here's a preview.

(http://www.billporter.info/wp-content/uploads//2010/08/Arduquee.png)

That board is 5cm x 3cm.

More info on what it does in a few weeks when i get them built.
Title: Re: Need: technique to connect PCBs using only a small footprint.
Post by: voyager2 on August 29, 2010, 05:32:14 AM: That is swashed Madsci!
But what is this for!
Your not telling us something...
Title: Re: Need: technique to connect PCBs using only a small footprint.
Post by: madsci1016 on August 29, 2010, 10:05:46 AM: Quote from: voyager2 on August 29, 2010, 05:32:14 AM
That is swashed Madsci!
But what is this for!
Your not telling us something...

Quote from: madsci1016 on August 28, 2010, 08:57:02 PM
More info on what it does in a few weeks when i get them built.

Only time will tell
Title: Re: Need: technique to connect PCBs using only a small footprint.
Post by: madsci1016 on September 05, 2010, 08:04:08 PM: Quote from: voyager2 on August 29, 2010, 05:32:14 AM
But what is this for!

No guesses?

Well, here's a spoiler. I just got it working.

(http://www.billporter.info/wp-content/uploads//2010/09/IMG_3011.jpg)

I'm calling it Arduquee, an Arduino powered Marquee. The boards fit together to create a marquee of any length, and the first board will be the 'controller' with a Atmega 328. Has three colors, Red, green and orange (red plus green) and only requires 6 I/O pins. The controller will also have a 5V 2A voltage regulator to power it as well. The PCB was designed so that it could be a controller or slave, just depends what you populate it with.

If there's enough interest, I'm thinking of open-sourcing the design and selling kits.

Proper post coming in a few weeks when I really get it going.
Title: Re: Need: technique to connect PCBs using only a small footprint.
Post by: Admin on September 05, 2010, 09:07:19 PM: nifty! I can see people buying it . . . expandable LED display boards . . .

Make sure you get a video of the Axon controlling them - cross promotion! :P
Title: Re: Need: technique to connect PCBs using only a small footprint.
Post by: madsci1016 on September 05, 2010, 09:27:20 PM: Quote from: Admin on September 05, 2010, 09:07:19 PM
Make sure you get a video of the Axon controlling them - cross promotion! :P

I'm planing on entering SAGAR in SFE's next Autonomous challenge, I could mount this all around it and have 'electronic' ads running during the race.

hehe.
Title: Re: Need: technique to connect PCBs using only a small footprint.
Post by: madsci1016 on September 08, 2010, 04:07:38 PM: Started a new thread on it btw,

http://www.societyofrobots.com/robotforum/index.php?topic=12054.0 (http://www.societyofrobots.com/robotforum/index.php?topic=12054.0)
Title: Re: Need: technique to connect PCBs using only a small footprint.
Post by: Asellith on September 09, 2010, 01:27:26 PM: what about something like this

http://www.mouser.com/ProductDetail/Molex/19-09-2159/?qs=sGAEpiMZZMtsLRyDR9nM13pBL8rF0ymp26GP6iRWBGU%3d (http://www.mouser.com/ProductDetail/Molex/19-09-2159/?qs=sGAEpiMZZMtsLRyDR9nM13pBL8rF0ymp26GP6iRWBGU%3d)

It is a 3 row connector. Don't use the center row and jumper the other two together. then your boards can have standard headers in them and the connector is easy and cheap. This one will not work but digging into molex's catalog will get you what you need.