Zero/low insertion force 20 pin connector for testing rig - Page 1
Forum section: electronics / projects

author: daqq
author_rank: Super Contributor
timestamp: July 06, 2017, 08:10:09 am
content: Hi guys,For a testing device I need to connect around 12 20pin connectors (classic IDC, two row, 2.54mm pin spacinghttps://img.fasttechcdn.com/100/1002400/1002400-2.jpg) to the device under test. This will get pretty annoying, since a fair amount of force will be needed, it will take some time, and disconnecting the connectors will be pretty time consuming and will cause wear on the cables of the testing device, particularly, since it should last several thousand matings. Essentially, it will be pretty time consuming, with a chance for an error (connecting the wrong cable in the wrong connector) and a lot of force needed to both push the connector in and pull it out.Is there any kind of zero insertion force connector that could mate with the counter part (https://ae01.alicdn.com/kf/HTB1WtDaOXXXXXcmXFXXq6xXFXXXt/5Pcs-Per-Lot-1-27mm-Pitch-2x10-font-b-Pin-b-font-font-b-20-b.jpg), or any way to make a lower insertion force connection? Or any ideas?Sadly, pogo pins are not an option in this case for various reasons.The currents will be relatively low. The voltages will be low as well.Thanks,David

author: capt bullshot
author_rank: Super Contributor
timestamp: July 06, 2017, 10:43:00 am
content: Pogo pins would have been the method of choice ...What I've done before with some success is building an adaptor out of these:andForce will still be high at the first cycles, they wear out with repeated use but do still have quite good contact then, so pushing and pulling gets easier over time.Since you leave them stuck at the cable side IDC connector, stress and wear on that part will be reduced.

author: Ian.M
author_rank: Super Contributor
timestamp: July 06, 2017, 12:16:20 pm
content: I'm assuming the 10x2 0.1" pitch box headers are on the D.U.T. so that's what the ZIF solution must mate to.You've really backed yourself into a corner by excluding pogo pins.If you had 1.5mm head diameter concave head pins in an insulating guide block drilled with 1.6mm holes, the guide block would have 0.94mm wall thickness between holes - adequate for strength, and could be shaped to be a sliding fit in the box header. With the edges bevelled and the pin holes countersunk it should self-align easily.You then have the problem of retaining it in the header with sufficient force. Can the product stand the force of 240 pogo pins being simultaneously depressed against the ends of the header pins? Otherwise you'll need some sort of friction clamping mechanism that can grab the exterior of the box header shell, and some way of engaging the pogo assemblies consecutively so the D.U.T.'s PCB isn't subjected to an excessive bending force.Otherwise, for a non-pogo pin solution, one approach would be a custom plastic shell to fit over the pins and support them, with a slot down the middle, two lengths of flat-flex PCB with 0.1" pitch gold plated ends, and some sort of mechanism to resiliently clamp the flat flex against the side of the pins between the two rows when actuated. Miniaturising the actuator to fit the 1.9mm gap between the header pin rows and still leave room for two pieces of flat-flex is going to be a bitch. Replacing the flat-flex when it inevitably fails due to repeated flexing against the hard edges of the square pins is going to be a maintenance P.I.T.A

author: firehopper
author_rank: Frequent Contributor
timestamp: July 06, 2017, 11:31:34 pm
content: either pogo pins or use IC ZIF sockets with a dil ic looking thing that the wires are soldered to.

author: daqq
author_rank: Super Contributor
timestamp: July 10, 2017, 06:54:31 am
content: Thanks guys for the tips.I've already been investigating the option that capt bullshot suggested - they work better than a classic IDC, but need a PCB to hold them - which would be OK I suppose.