Test clip that can reliably connect to unpopulated header pin? (30-40mil = 0.76 - 1.02mm diameter; 3/64" - 1/10" thick pcb)Started by 2 years ago●5 replies●latest reply 2 years ago●174 views
I have a need to connect nondestructively to an unpopulated header pin on a PCB. PCB thickness is typically 1/16" thick (1.59mm) but could be in the 3/64" - 1/10" range (1.19mm - 2.54mm); header holes are in the 30-40mil diameter range (0.76mm - 1.02mm).
Is there any kind of an off-the-shelf test clip / test hook that can reliably hook onto the inside barrel of a plated-through PCB hole in this size range?
I have used two methods.
The first is to use a 0.025” square post header. The diagonal of the square post is a little over 0.035”. The holes should be 0.036” to 0.040” to provide a snug fit. With test leads or wires connected to the square post header, there is enough side pressure between the post and the plated through holes to make electrical contact. I have used this for connecting to microcontroller debug headers on PCBs.
The second method is to use a spring type test point, such as the Keystone part number 5001, inserted into the plated through hole. The spring pressure against the plated though hole provides electrical contact.
I agree with waltz.
My favorite spring loaded contacts come from Mill-Max
I'm not sure this is quite what you're looking for but these guys:
do a wide variety of headers and clips, mainly for small footprint JTAG/SWD connectors. The through hole ones remove the need for a JTAG header on production boards which saves a bit of cost and also board real estate.
last time i have used just some square post headers and tilted theme a little so that there was solid contact. (similar as waltx mentioned)
next time i will try to use something like this:
there are different manufactures for these spring-loaded contact probes.
they are not locking themselves to the connections but if you press theme down its an reliable connection - and you are not fixed to a specific hole size. it can vary a litte...