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Electronics => Electronics => Topic started by: krich on May 24, 2008, 12:18:20 PM

Title: Bus Connectors?
Post by: krich on May 24, 2008, 12:18:20 PM
I've come up with a scheme for building reusable parts for my projects.  It involves a bit of board stacking, up to 4 high in some extreme cases.  I've been having a hard time finding a suitable board to board bus connector.  I'm going for something similar to the stacking capabilities of the PC/104 platform, but all I need is 8-10 pins and a smaller price tag.

I'd like the PCBs to stack right on top of each other with a solid interconnect between them.  To give you an idea of what I'm talking about, think about a female header receptacle with 0.75" or longer solder (or wirewrap) tails that will connect to a similar board below.  The bottom-most board would be the main MCU board and would not have these long tails underneath.

I've tried wirewrap SIP sockets, but the wirewrap pins don't fit into the sockets.  If anyone has figured this out, I could certainly use the help to find a suitable connector.  I'm guessing the max current through the pins will be less than 1A, so they don't have to be "purpose built" for this application.

I was thinking a standard female header on one side, and a surface mount male header on the other.  That's a bit of soldering work with plenty of room for gross alignment issues.  Any other ideas?   :-\

Edit:  Currently the boards are designed with a 1x9 bus connector.  That could be changed to accommodate a good solution.
Title: Re: Bus Connectors?
Post by: paulstreats on May 25, 2008, 01:47:08 PM
The female header on 1 side and the male headers on the other sounds lie the best bet.

You are likely to want female headers on the underneath side so you might have a problem soldering them if you are just woring off aq prototyping board. To get around this, you can get surface mount version which are the same its just that the solder pins are solder tags and are bent at 90 degrees. (theyre not as common as the through hole version but ive used them before)
Title: Re: Bus Connectors?
Post by: krich on May 25, 2008, 07:38:53 PM
Thanks paulstreats.  It's good to hear from one of the veterans. 

What I'm doing now is exactly what you are suggesting.  Male header on one side, female w/ leads bent in alternating SMD fashion on the other.  Its just a heck of a lot of fine soldering work when all I need is a female header with extended solder tails. 

At first I decided to do the male header on top, but found that it was easier to breadboard things in development if the female headers were on top.

Thanks again.
Title: Re: Bus Connectors?
Post by: jka on May 28, 2008, 03:08:30 AM
You could use the PC104 stackthrough connectors like these: http://www.emulation.com/173/
Title: Re: Bus Connectors?
Post by: krich on June 29, 2008, 10:27:36 PM
Hehe, that's the kind of link I was looking for.  Single row PC/104 connectors. 

Since my last post, I was able to find a reasonable source for stacking connectors.  They are the ESQ series of connectors at Samtec.  Specifically, I sampled ESQ-109-14-G-S, which is basically a female header receptacle with a very long solder tail.  This allows the solder tail to connect to the receptacle on the board below.  Not exactly cheap at about $1.40 for a 9-pin connector, but they fit the bill perfectly.
Title: Re: Bus Connectors?
Post by: Asellith on June 30, 2008, 10:16:51 AM
Another idea would be to use standoffs to mount the boards to each other and then a short ribbon cable to connect between standard header strips.

something like this

http://www.alliedelec.com/Search/ProductDetail.aspx?SKU=6180052&MPN=1M-1010-010-3365-006.0&R=6180052&SEARCH=6180052&DESC=1M-1010-010-3365-006.0 (http://www.alliedelec.com/Search/ProductDetail.aspx?SKU=6180052&MPN=1M-1010-010-3365-006.0&R=6180052&SEARCH=6180052&DESC=1M-1010-010-3365-006.0)

Kinda pricey but you might be able to find them cheaper somewhere else with a little searching