Electronic – Pogo Pins for 1.5mm Pitch Test Fixture

Pogo pin test fixtures should not use pogo pins for the alignments posts for the DUT (device under test). Instead the proper method is to use machined metal posts that slide into two or more mounting or guide holes of the DUT. These posts are secured to the same base plate that the pogo pin sockets are mounted. The alignment posts are tall enough that they locate the board before it engages with the testpoint pogo pins.

Sometimes you can use a technique to lower the friction of the alignment posts in the holes of the DUT by specifying three flats on the sides of the alignment posts as shown here:

^{(Note that the flats would normally be uniform and less exaggerated than shown in this quick sketch).}

Pogo pins are designed to be placed in pogo pin receptacles or sockets, slightly larger sleeves made of similar material.

Your P50 pogos would use an R50 socket, P75's would use an R75 and so on. Knowing that will drastically improve your chances of finding an online vendor.

Common socket forms have an indented rear to which fine wire can be soldered and covered with tiny heatshrink after the socket is pressed into a CNC drill hole in a carrier plate. You can also sometimes see them sold with wires already attached, which saves some fiddly handwork.

At least in the R75 size in addition to the solder form (such as R75-3S), you can get sockets ending in a square header pin (R75-2W) which you could wire wrap to, or possibly even use a socket jumper wire, or if you match a standard header IDC ribbon cable connector on.

In a pinch you can carefully solder to the pogo itself; the downside is that if it wears out, bends, or start sticking in use, you then have to replace the wiring too. In contrast, if sockets are used you just carefully extract the bad pogo with pliers and put in a new one.