Micro Grabbers for ICs - Page 1
Forum section: electronics / repair

author: zz28zz
author_rank: Regular Contributor
timestamp: August 01, 2017, 11:32:45 pm
content: Is there a certain type of mini/micro grabber I can use to connect a scope to IC pins?We have regular mini grabbers but they are too big to connect to a pin without risk of shorting to adjacent pins.Thx

author: tautech
author_rank: Super Contributor
timestamp: August 01, 2017, 11:59:55 pm
content: The Tek grabbers work OK down to SOIC.See old post:https://www.eevblog.com/forum/repair/suggested-for-a-sticky-part-one-comments-or-additions-please/msg471163/#msg471163

author: alm
author_rank: Super Contributor
timestamp: August 02, 2017, 12:25:02 am
content: Here is a nice list.For sizes from DIP (0.1") down to SOIC (0.05") I like theTektronix SMG50 ChipKliporEZ-Hook XKMtype (HP/Agilent shipped the same type with their logic analyzers). Both are regularly available on eBay for something like $1/each. All of the cheaper knock-offs I have tried performed terribly.For smaller than SOIC things get expensive and fragile fast. The TPI NC1 is the cheapest of the brand-name ones in this category. I do not have experience with the AliExpress grabbers referred to on the Sigrok wiki page.Most of these grabbers have 0.025" square pins. The best way to attach a scope probe to that is an adapter likethis. These are not universal, so the best way is to buy one made by your probe manufacturer.Keep in mind that every mm of wire you add degrades performance of your probe (which is why a purpose-made adapter is the best). Every reference you see to keeping the ground lead short and using a low-inductance ground spring for best signal integrity applies equally to extending the probe tip. How much depends on the signal frequency / transition time, and the input capacitance of your probe (lower capacitance means less degradation due to the extra inductance). If your bandwidth needs are very low, you can do the crappy thing of clipping the retractable hook to a piece of wire. When in doubt, put the probe tip directly on the test point to exclude issues caused by the long wires.

author: DaJMasta
author_rank: Super Contributor
timestamp: August 02, 2017, 12:45:47 am
content: I've got some of those small gray spring hooks and they're great on regular lead spacing SOICs, but they're a little large for the small pin pitch stuff. For really fine work, I always go back to mod wire. You are assured a good electrical connection if it stays put and provided you inspect your work, you can make sure there's no accidental bridging and no extra mass to eventually pop off when you're trying to probe with a so-so grab on the pin.

author: Assafl
author_rank: Frequent Contributor
timestamp: August 02, 2017, 03:39:13 pm
content: I grabbed a bunch of Mechano Japan grabbers like this for about 50$ (about 40 micro grabbers) from Halted Specialties.http://www.mechano.co.jp/pdle2.htmlThey are really nice but too expensive new...

author: alm
author_rank: Super Contributor
timestamp: August 02, 2017, 04:39:23 pm
content: $1.25/ea is an excellent price for those grabbers. Normal price is well over ten times that.

author: zz28zz
author_rank: Regular Contributor
timestamp: August 02, 2017, 07:07:47 pm
content: Wow! Thx for all the replies. I'm dealing with older ICs. Pitch is ~0.1" or 2.54mm. Think I'll go with the Tektronix SMG50 ChipKlip mentioned in the reply from alm.

author: bd139
author_rank: Super Contributor
timestamp: August 02, 2017, 07:25:51 pm
content: Whatever you do, avoid the Pomona micrograbbers. They are crap!

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: August 02, 2017, 07:35:36 pm
content: Apart from full test clips, which grab and contact all pins of a device (available in SOIC, PLCC, TSOP), I have made very good experiences with the so called WEDGE PROBES, which are shoved in between the pins and contact a pin on both sides. They end on 0.64mm squares and are available in various pitches and pin counts. Mine are HP, but I think they have licensed them to another company too.

author: alm
author_rank: Super Contributor
timestamp: August 02, 2017, 07:55:00 pm
content: Quote from: bd139 on August 02, 2017, 07:25:51 pmDo you meanthese? I am a bit surprised that they make total crap (I have only had good experiences with their products), but I do not really see the point of them: if stuff is large enough to fit a hook around (e.g 0.025" 100 mil square pins), there is generally space for a larger minigrabber. If space is tight (IC), you are better off with the pincer style that comfortably go down to 50 mil.

author: bd139
author_rank: Super Contributor
timestamp: August 02, 2017, 09:32:46 pm
content: Yeah they are the ones.The minigrabbers are very good and I use them regularly but the micrograbbers are total junk.

author: rdl
author_rank: Super Contributor
timestamp: August 02, 2017, 09:38:05 pm
content: I have some of the Pomona Mini Grabbers that have been in use for over a decade I guess. I bought a few of their micro size clips a couple of years ago and haven't had any problems with them yet.

author: bd139
author_rank: Super Contributor
timestamp: August 02, 2017, 09:48:19 pm
content: I broke all mine in about 5 minutes. Then again I am ham fisted

author: alm
author_rank: Super Contributor
timestamp: August 02, 2017, 11:36:22 pm
content: Quote from: rdl on August 02, 2017, 09:38:05 pmWhere do you use the Micro Grabbers over Mini Grabbers or pincers? For me the mini grabber is the go-to for anything through-hole except DIP, though I sometimes use the similar-sizedParrot clipsinstead for their lower constant resistance and ability to act as probes.Anything fine pitch (including DIP due to its small distance between the pins) I use pincer-type clips because even if it is thin enough, wrangling a hook between them and especially out is too annoying and I do not trust them not to short a pin. Pincers (even the larger ones) do not work well for anything larger than a 1/4 W resistor lead. They are usually barely able to hold the weight of the lead.

author: rdl
author_rank: Super Contributor
timestamp: August 03, 2017, 04:23:32 am
content: The Pomona micro size is a pincer type, similar to the EZ-Hook kind. The lead of that 5mm LED is about the biggest thing they will fit on. I use them mostly to clip on IC leads, DIP or smaller.

author: Andreas
author_rank: Super Contributor
timestamp: August 03, 2017, 09:07:13 pm
content: Hello,I have a set of these for measurements on SMD-Pins:https://www.reichelt.de/Banana-Plugs-Toy-Plugs/MS-6800-8/3/index.html?ACTION=3&GROUPID=7473&ARTICLE=63477&OFFSET=100&With best regardsAndreas

author: Samogon
author_rank: Frequent Contributor
timestamp: August 04, 2017, 06:18:13 am
content: Option to considerhttps://www.digikey.com/product-detail/en//5514/501-1638-ND

author: Assafl
author_rank: Frequent Contributor
timestamp: August 04, 2017, 06:18:15 pm
content: Same thing for 224$ from Pomona and under 70e from reichelt?Danaher pricing is annoying.

author: Andreas
author_rank: Super Contributor
timestamp: August 04, 2017, 06:55:23 pm
content: Hello,I think the kit from DigiKey corresponds more to that set:https://www.reichelt.de/Banana-Plugs-Toy-Plugs/MS-6800-12/3/index.html?ACTION=3&GROUPID=7473&ARTICLE=63479&OFFSET=100&But also less than half the price.with best regardsAndreas