Hi, I'm wondering if there is a solution to the mechanical constraints of my project. Without going into the details, I want to connect a ribbon cable to the back side of my circuit board. Normally, I'd use a generic pin header for this, but the clearance between the case and the back side of the board does not allow for the height of the ribbon connector, plus the height of header base. That got me wondering, could I cut a rectangular hole in my board and then get a U shaped header which soldered to the front of the board and then made two right angle turns to face down, allowing a connector to come up through the hole into the pins, leaving the ribbon cable pretty much flush with the board.
Does such a pin header exist?
Thanks!
I think what you are looking for is inverted headers. It is not what you describe but may be a better choice for your application.
Why such a convoluted solution? I simply use a row or two of "wire-wrap" pins from a spare socket, solder them into the holes, and trim the unwanted length (and socket). Leaving only bare pins protruding directly from the board.
i cant find them for sale because i dont know what they're called, but you can get 2 wire looped U shape 2.54mm headers..
If you use a u-shaped header, every time you plug or unplug the connector, you'll be putting a lot of torque on the pins and their connection to the board. Not a good thing for reliability. It would be better to create a 'mezzanine' board that was solidly attached on both sides of the hole and includes regular header pins. The board sits above the rectangular hole in the board with the pins pointing through the hole. Space the mezzanine board above the main board so that when you plug the connector in from the bottom, the ribbon cable is almost flush with the bottom of the board.
Ed
Have you considered smaller connectors?
JST makes some quite thin connectors, with pitch from 1.5mm to 2.5mm... see JST ZH for example (page 2 for right angle connector) :
http://www.farnell.com/datasheets/621906.pdfFarnell stocks them.
Thanks everyone for you helpful input!
miguelvp: That's pretty much what I was thinking of, I'm surprised that my google searches didn't turn any of those up.
edpalmer42: That's a really good point, I hadn't thought about the mechnical torque. I had considered the mezzanine board, but it results in two more pin headers and a pcb, which will add to the BOM costs, however I might end up going that way in the end.
Jeroen3 and Richard Crowley: Yeah, I know it's a pretty complicated solution, I'm tring to think of some good way to reduce the height, and your ideas help with that.
WarSim: Yeah, inverted headers with a mezzanine board might be the way I go.
Psi: What you found is exactly what I had found, u shaped headers, which are perfect for fastening something down, or using as clip-on test points, but not for connecting a ribbon cable from the under side.
mariush: Thanks for the lead, I was hoping to use a mid-cable connector, as opposed to an end, but searching for "low profile connectors" actually turned up some promising leads.
Thanks again everyone for your help. I've only just started wading into the pool, and your input has been invaluable. It sounds like the part I'm looking for doesn't exist becuase it just wouldn't be strong enough.
What about a Right angled std 0.1" female header, located next to the rectangular cut out in the pcb, and make use of some right angled male 0.1" headers pushed into it? You may have to push in the male "turn the corner" headers BEFORE you solder the female RA header to the pcb of course!
ie: this on top side of pcb
use this as "right angle link" to end up with pins pointing down through slot in pcb:
That should work, and if you use "dual row" types, should be quite robust too (as they will resist the "torque couple" forces better
i cant find them for sale because i dont know what they're called, but you can get 2 wire looped U shape 2.54mm headers..
Just in case anyone is still looking for these. They are called solder anchors and here is the link for them at digikey.
http://www.digikey.com/product-detail/en/125700D00000G/HS400-ND/1216404I just had to order some today for a motherboard I am repairing. How the anchors fell out from the board solder and all I have no idea, but they were missing and the heatsink had dropped on the backplane.
I just had to order some today for a motherboard I am repairing. How the anchors fell out from the board solder and all I have no idea, but they were missing and the heatsink had dropped on the backplane.
There's been a lot of issues with those (I've got a motherboard lying around where the same happened - think it got bumped during transport). For some idiotic reason, they're usually soldered to a very undersized pad which often pulls through the board. Because obviously having a large annular ring on something subject to a ton of force is completely unnecessary...