Best way to probe fine pitched pins

[apelly]

I'm considering sewing needles...

Any better ideas?

[alm]

What do you consider fine pitch? I consider 50 mil pitch coarse and easily probeable with standard probes / clips. Anything less requires special tools. This page gives a decent overview of clips designed for various SMT packages. The EZ-hook / Tek probes are fine down to 50 mil, below that you want what that page describes as 'high-end probes'. For browsing I like a sharp spring-loaded tips that allow you to exert less force without having the probe slip, for example the Pomona 6341 / Fluke TL-910 leads, Pomona 72923 probes (pretty sure these are not made by Pomona, they require 2mm leads) or Hirschmann Prüf 2610 probes (though the long distance between handle and probe tip is annoying).

[rolycat]

If you are on a budget but want something finer than standard probes, needle probes like these may fit the bill:

http://cpc.farnell.com/1/1/100996-test-probes-needle-red-black-72-9320-tenma.html

Only a couple of NZ$.

[alm]

Are these any finer than the standard 0.080" (2 mm) probes typically shipped with DMMs? The drawing appears to indicate they're not.

[apelly]

What do you consider fine pitch?

I want to have a poke around a qfn-32 on a netbook motherboard. If that's not the problem then there's a bunch of stuff around .3mm pitch.

The issue isn't so much the money for new probes (although the big guys really piss me off with their prices in NZ) it's more about the convenience of being able to get something today

Thanks for the pointers guys.

[rolycat]

Are these any finer than the standard 0.080" (2 mm) probes typically shipped with DMMs? The drawing appears to indicate they're not.

Hmm.. Probably not. They looked similar to my Fluke TP88 probes, which are 1mm in diameter and have very sharp points, but I don't own the Tenma probes.

[ovnr]

I've got a pair of Pomona 6341 probes, which are excellent for this kind of thing. Highly recommended, if a bit pricey ($40).

[RRobot]

You can buy an assortment of SOIC/PLCC and other test clips as well. Kinda expensive, but handy for some standard packages.

For instance:

http://www.pomonaelectronics.com/?i=prodmain&getDetails=&parent=ICCLIP

or

http://www.tequipment.net/PomonaTestClipsIC_QFP.asp

[rolycat]

If you need a solution right now I've just tried clamping a sewing needle to a probe tip with some heat shrink tubing and it seems to work surprisingly well. I imagine the useful working life is rather limited, though.

For very fine work, a set of test clips recommended by another forum user is here:
http://www.rapidonline.com/Cables-Connectors/Smd-Test-Probe-Set-17-2576/?sid=e948704c-4952-4d2e-a567-d83276a7a1f4

This is a set of eight smd probes which clip onto pins down to 0.2mm pitch.

[alm]

In a pinch I've also clamped a sewing needle / pin in a crocodile clip.

I believe PJP is the original manufacturer for the Pomona 70000-series SMD probes/clips. These are the same as the Pomona 72923 probes I mentioned.

[apelly]

If you need a solution right now I've just tried clamping a sewing needle to a probe tip with some heat shrink tubing and it seems to work surprisingly well. I imagine the useful working life is rather limited, though.

Just gave this a go. Awesome idea! It is indeed surprisingly good!

In a pinch I've also clamped a sewing needle / pin in a crocodile clip.

Now you tell me!

But seriously, you can never beat the proper tool for the job. I'll order something decent this week. That first set of Pomona 6341's looked good, also the set from Rapidonline Smd Test Probe Set that rolycat suggested (URL corrected)

[pickle9000]

Pogo pins work well.

[JuKu]

I have a sharp probe, can't remember where I bought it, but...

I have an Einstein action figure (seriously!) with a rubber band attached to his hand holding the probe. He leans over and holds the probe for me, freeing both my hands to operate the scope or the computer (USB logic analyzer, giving commands to trigger what ever I try to measure etc).

[pickle9000]

That deserves a picture, while probing. 

[amyk]

I have a sharp probe, can't remember where I bought it, but...

I have an Einstein action figure (seriously!) with a rubber band attached to his hand holding the probe. He leans over and holds the probe for me, freeing both my hands to operate the scope or the computer (USB logic analyzer, giving commands to trigger what ever I try to measure etc).

Genius!

I've used needles embedded in modeling clay before, but now that I think about it, action figures' moveable appendages may actually work quite well...

[apelly]

Pfft. Eienstein?

I have Spiderman!

[GreyWoolfe]

I have a set of leads that i made that has very small brad nails soldered into the alligator clips to assure continuity.

Tom, NW0LF

[flatmax]

Hi there,

This is 0.1" but is similar to what you need ... very handy for prototyping !
https://www.kickstarter.com/projects/1250664710/pcb-quick-connect-clip-40-pin-raspberry-pi-compati/?ref=eevblog


Matt

[Brumby]

Hi there,

This is 0.1" but is similar to what you need ... very handy for prototyping !
https://www.kickstarter.com/projects/1250664710/pcb-quick-connect-clip-40-pin-raspberry-pi-compati/?ref=eevblog


Matt

Only 4 years too late ....

Kinda missed the "today" requirement ... and the target geometry.

[jmelson]

I'm considering sewing needles...

Any better ideas?

I have made converters with a .080" pin jack soldered to sewing needles.  The problem is most sewing needles are EXTREMELY hard to solder to.  I put the needle against the contact of the tip jack and wrap with wire, then glob solder over it all.  It usually holds together, looks awful, and sometimes the needle works loose.  But, it is great to be able to poke it onto a single lead of an 0.4mm pitch chip.

Jon