Looking for low-cost connectors

[justanothercanuck]

Looking for some connectors to link a few boards together for a project I'm working on...  The one set of connectors is a board-wire-board power connector, 2 wires, 5 volts and no more than an amp.  The second set of connectors is board-board, but I need roughly 40 pins for signals (to connect to a backplane).

I've looked at molex connectors and berg connectors for the power, but they're too expensive.  For the signal connectors, I've considered PCI, DIN 41612, and even 40-pin IDE connectors, but they're also too expensive.  Sure, they would be cheaper if I bought them by the thousand, but I only need 6 or 7 sets of each connector.  Not to mention, I'd need to buy a crimper.

Aside from just soldering the boards together, is there a cheaper way to make connections?

Thanks

[c4757p]

I'm confused. Is this meant to be direct board-to-board or via a cable? If it's via a cable, with that many signals, I'd probably go with the IDE connectors. Just two rows of twenty 100mil pins - you can even omit the shrouded connector - and pre-made IDE cables are dirt cheap. If it's direct I'd put some work into eliminating some of the signals (are you sure you can't encapsulate them in a serial protocol or something?) and use a card-edge connector. Mouser has PCIe x1 sockets for less than 50c each.

[justanothercanuck]

Sorry for the confusion.  Let's see if I can clear that up a little.  The power connectors would be a wire with connectors on both ends.  The signal connectors, I'm building a backplane for the boards to talk through, I just need connectors for them. 

40 pin IDE connectors cost like $5 a piece, which I don't understand because it's a common connector. 

[Marco]

What's wrong with cheap pin header/sockets like arduino uses? (Other than that they are not rated for a whole lot of insertion cycles.)

[LEECH666]

Have you considered 37 to 50 pin D-SUB connnectors for the signals?

http://www.newark.com/multicomp/5502-50pa-01-f1/plug-d-pcb-straight-50way/dp/93K4308?Ntt=1084691

Sure they ain't high density and a bit clunky, but they're cheap and well proven, they might not meet your space/size requirements tho (you didn't specify).

Cheers,
Florian

[justanothercanuck]

Have you considered 37 to 50 pin D-SUB connnectors for the signals?

Aren't those meant for external connections?  I'm not sure those would work that great for me.

[madires]

40 pin IDE connectors cost like $5 a piece, which I don't understand because it's a common connector. 

That seems to be a rip-off. Just checked a local online shop: 0.20 Euros.

[mariush]

http://www.digikey.com/product-detail/en/SFH11-PBPC-D20-ST-BK/S9200-ND/1990093
http://www.digikey.com/product-detail/en/SBH11-PBPC-D20-ST-BK/S9175-ND/1990068

1-2$ a piece depending if it's female or male connectors. You can probably find them cheaper.
You can use the regular rows strips of pins that can be bought cheap on ebay, even at vertical angle ... or get something like this

http://www.digikey.com/product-detail/en/SBH11-PBPC-D20-RA-BK/S9183-ND/1990076

http://www.digikey.com/scripts/dksearch/dksus.dll?FV=fff40016%2Cfff802f3%2C114016f%2C1140215%2C1600017%2C8000010%2C8cc0003&vendor=0&mnonly=0&newproducts=0&ptm=0&fid=0&quantity=0&stock=1

IDE cables are cheap but be careful because I think one pin is missing in the 40pin connector, so you'd actually have 39 signal wires.

There's another option ... put the contacts at the edge of the board and use such connectors:
http://www.digikey.com/product-detail/en/5530843-4/A31717-ND/770543

But you'd have to be careful when making the board, to be thick enough so the contacts would be good.

[Paul Moir]

D-SUBs are sometimes used internally.  At least I'm sure I've seen them used for a backplane on *something*.  You can get them in not-right-angle for a backplane.  But pin headers have to be cheaper.  (I do see a $2.29 37 pin d-sub at Digikey though).

But what I really wanted to know is if there's a particular reason you want to keep your power on a separate connector?  If if doesn't matter, just devote a few parallel pins for power and ground.

[justanothercanuck]

http://www.digikey.com/product-detail/en/SFH11-PBPC-D20-ST-BK/S9200-ND/1990093
http://www.digikey.com/product-detail/en/SBH11-PBPC-D20-ST-BK/S9175-ND/1990068

1-2$ a piece depending if it's female or male connectors. You can probably find them cheaper.

Those will fit the bill nicely, but is there a right-angle male connector to go with it?  I didn't happen to see one.  I saw one by another manufacturer, but it was like $4.70 a piece.

But what I really wanted to know is if there's a particular reason you want to keep your power on a separate connector?  If if doesn't matter, just devote a few parallel pins for power and ground.

Signal noise I guess?  It also saves me from running extra traces through the backplane and/or one of the boards. 

Thanks again

[Psi]

The cheapest connectors will be ones used for other purposes in mass market products like PC components etc..

[mariush]

http://www.digikey.com/product-detail/en/SFH11-PBPC-D20-ST-BK/S9200-ND/1990093
http://www.digikey.com/product-detail/en/SBH11-PBPC-D20-ST-BK/S9175-ND/1990068

1-2$ a piece depending if it's female or male connectors. You can probably find them cheaper.

Those will fit the bill nicely, but is there a right-angle male connector to go with it?  I didn't happen to see one.  I saw one by another manufacturer, but it was like $4.70 a piece.

Digikey is full of connectors and pins, you can waste hours just searching.
Look up the connectors sections, filter by  pitch 1.27mm and 2.54 mm, number of rows and pins, even right angle or not..

http://goo.gl/kz0jh

The plain unshrouded pins are very cheap, under 2$ for a 40 pin set... but you could be smart and play with volume prices even though you need just a few. Instead of getting 40 pin, get 20 pin or 10 pin and buy in volume, price may actually be better if you get 100 pieces of 10 pin compared to 25 x 40 pin connectors.

http://goo.gl/euaaz

(scroll down, 40 pin connectors start from around page 3... the link above filters to show only straight, surface and through hole, with 1.27 and 2.54 mm pitch/row spacing)

And digikey isn't even the cheapest, but they're close to canada, much like mouser.com is or ca.newark.com

the ones that are male unshrouded you may be able to get from eBay really cheap (it's the same spacing as the breadboard holes so you can find them as breadboard accessories)  but you don't have the guarantee that the pins have gold plating on them, or you have female + male from the same alloy... it's little things but it can matter.


I think it would be cheaper to put a straight male pins on the base board and a female at vertical board, the regular straight pins are cheaper