PCB Edge-to-Edge Connectors? (Looking for Recommendations)
JonnyMac
Posts: 9,159
I'm putting together a PCB for a friend taht he'd like to stack edge-to-edge. Any recommendations on a connector set? The buss through the boards is four pins.
Comments
For mechanical strength, Molex KK 254 system connectors with friction locks work well. Check out these two TH parts: Molex 22-15-2046 & 22-05-3041
Here's a non-mechanical strength example using Samtec SMT headers and receptacles. To use 4 pin of the same, Samtec part numbers would be: MMS-104-02-L-SH & MMT-104-02-T-SH
When I was exploring this, I preferred soldered connections for less connection issues(Especially on Neopixel boards stacked edge to edge). Jumper wires come in all different lengths. A bag of 200 is 20.00. That is $.1 per jumper.
specifically these: (female to female plugs, so no soldering)
http://www.mouser.com/Connectors/Board-to-Board-Mezzanine-Connectors/_/N-ay0krZscv7?Keyword=9159+4P&FS=True
and also in Lighting Connectors
http://www.mouser.com/ProductDetail/Hirose-Connector/DF59-4P-2FC50/?qs=sGAEpiMZZMsAnMfEB9lOQCLuYNNQ2AgstNRcc5GPYzU%3d
This is about modularity and serviceability -- soldered connections are not an option.
Here are a few things I've tried.
Here are my little WS2812B boards with normal headers and jumpers used to link the boards together.
One difference my boards had was a slightly curved board edge. The curved edge made boards fit together better than the small WS2812B boards Parallax sold.
Here's the thread: http://forums.parallax.com/showthread.php/149822
I also used more conventional connections with my LED array boards.
In order to take advantage of the 5cm x 5cm prices of the cheap fab houses, I placed the header holes pretty close to the edge of the board.
Here's the thread on this project: http://forums.parallax.com/showthread.php/143775
I thought the boards stayed together reasonably well even though the physical PCBs didn't meet.
The 8x8 array by SimplyTronics uses a six pin connector even though only three pins are needed.
The double row of pins makes the connection between boards much more rigid than using a single row of pins. Depending on the specifics of the application, an eight pin connection may work better than a four pin connection.
My latest 8x8 LED array PCBs use a double row of headers and I like how the boards connect together with two rows of pins much more than the way the boards had connected with a single row of pins.
Top and bottom side of board: {pin-M} | {F-pin} A ------> | >------ A B ------> | >------ B C ------> | >------ C D ------> | >------ DFrom the side it's like:
TOP +-----------------+ pin | male > female | pin PCB ======== | --------------- | ======== PCB pin | male > female | pin BOTTOM +-----------------+ ^------- Mated ConnectorsI've also seen people do simple ribbon cable things on one side if they need flex between boards.
Jon,
How are the modules being mounted? By stacked end to end, do you mean laid out in a flat array or stacked like poker chips?
If doing a flat array, here is an idea. Try a small soft ridge of material about the thickness of a rubber band under the edges.Then assuming double sided boards, put etched contacts on the bottom edges. Glue/screw or otherwise anchor short length of flex PCB with the same trace count as pins. Mount them so that the bare ends match up with the boards. Securing the boards over the flex should get you a good interconnect. Not an original method, seagate and others use this in hdds, and various CT OEMs use this method to connect detector arrays to their backplane. As to maintainability, just need a screw driver. Unscrew the defective board and replace. If snap anchored, don't even need that.
Just an idea fer ya,
FF
I have at least found a photo of the solution, but I still have not found a source. Here is a lead link: http://www.isplc2006.org/b2b/crude_oil/1/pcb_connector_28.html
Bruce, these are often called "right angle headers." Most electronics distributors carry a variety of these. Here's SparkFun's selection:
https://www.sparkfun.com/search/results?term=right+angle+header
The SparkFun prices are a bit high compared to what you'll find elsewhere.
Here's some from Adafruit:
http://www.adafruit.com/search?q=right+angle+header&b=1
Digikey and Mouser's list of right angle headers will likely be huge. You can also search for these on ebay and Aliexpress but the quality might not be great.
If the distance between PCBs is important (as it was with my LED array project), then you'll want to make sure and have the physical connectors in hand when designing the board. The appropriate spacing between the holes will vary among models of headers. The spacing between the two sets of holes may not be 0.1' aligned.
I've appreciated seeing all the solutions people have offered. Lots of good ideas.
SparkFun's images are not showing up, so I cannot verify.
I have seen listings of right angle headers like this
but I have not seen listings for female headers like this
That 36 pin female strip at Adafruit is the only other that I have seen.
At first it looked as the Andrew's photo was using surface mount, but it now appears they may be TH.
The two purple square PCBs in post #7 are joined with a set of right angle headers. You can order male and female right angle headers from Digi-Key in just about any length. If you need help finding a part # let me know. I'll try to find an example and add a link to this post.
Here's a 6 position right angle female header at Digi-Key:
http://www.digikey.com/product-detail/en/PPPC061LGBN-RC/S5481-ND/775939
Here's a 16-position version.
http://www.digikey.com/product-detail/en/PPPC161LGBN-RC/S5491-ND/775949
They have a huge variety of right angle female headers.
For some odd reason, SparkFun's JPGs are not showing.... hmmmm
Anyhow, thanks fopr the digikey link, because I could not find them at mouser.
I suppose that would be a good route to go, especially if you occassionally use them. As it pertains to Jon's question, and my suggestion, I withdraw my suggestion of the combo male/female headers, because personally, I do not like the idea of several pins overhanging the edge. I would be more inclined to think that a right angle female header on each board would be a better answer, using a straight male header to connect the boards, providing the pins are long enough to make contact. Although the plastic strip may have to be manipulated a little.