MOSFET shipped in non-ESD conductive foam - Page 1
Forum section: electronics / general

author: blueskull
author_rank: Unknown
timestamp: April 19, 2017, 09:59:35 pm
content: I always have good experience with major distributors in terms of how they protect the parts, but not this time.This time, I got 2 MOSFETs in pink foam, the foam is tested with a UniT 2.5kV insulation meter, and shows ~13G resistance -- not exactly ESD conductive.Usually I expect the foam to be <10M resistance to effectively protect parts, just like those black foams.Also, the blue-greenish plastic bag is completely non conductive.BTW, Mouser's TO247 tube is also not quite conductive -- ~5G. ESD-dissipative, but not exactly ESD-conductive.Mouser's MOSFET foam is better -- standard black foam, <10M resistance.Any idea how this happens from Digikey? Any similar experience to share?

author: sleemanj
author_rank: Super Contributor
timestamp: April 20, 2017, 01:08:44 am
content: I seem to recall Dave (I think, maybe it was somebody else) got some stuff from Digikey (I think it was) once that was not properly packaged for ESD also, they apologised for the error and replaced it as I recall.I would certainly expect FETs to be shipped in metalised bags, "pink foam" inside such bag would be OK.Pink foam inside a non-shielding bag, nah don't think that's good enough from Digikey, that's barely better than a typical Chinese vendor.

author: thm_w
author_rank: Super Contributor
timestamp: April 20, 2017, 09:14:17 pm
content: Digikey will ship those blue ziploc bags inside of a metalized bag. I'm assuming you got that too, but didn't mention it?I see no problem with this, assuming it came in the metal bag, but I think its a bit overkill.VGs max rating is -8/+18V, 660pF, so I suppose it could be damaged if not handled carefully.edit: I don't see it in this device, but a similar cree device had following ESD spec,Code:Test Circuit Devices Sampled Resulting ClassificationESD-HBM All Devices Passed 1000V 2 (>2000V)ESD-MM All Devices Passed 400V C (>400V)ESD-CDM All Devices Passed 1000V IV (>1000V)

author: sleemanj
author_rank: Super Contributor
timestamp: April 21, 2017, 12:31:39 am
content: Quote from: blueskull on April 20, 2017, 09:33:04 pmIn that case, that's fine, assuming the "blue bag" is dissipative.No static will be generated inside the metalized bag, and the metalized bag prevents static discharge from outside the bag getting inside the bag.It seems wasteful to double bag it though.As for Chinese sellers, I'm just happen when parts arrive if they are not glad wrapped (saran wrap, depending on your part of the world) onto a rapidly deteriorating and static clinging to everything polystyrene block.

author: tautech
author_rank: Super Contributor
timestamp: April 21, 2017, 01:36:09 am
content: Quote from: blueskull on April 19, 2017, 09:59:35 pmContact them and have a real good bitch about it.That sort of behaviour is typical of some eBay and Aliexpress suppliers but I insist that they supply static sensitive devices in proper antistatic packaging and there's no good reason why Digikey should lower themselves to the same level.For eBay and Aliexpress sellers I give them fair warning that products need be provided in ESD packaging or negative comments will be placed or a case taken against them. I've even sent them ESD guideline pdf's to make clear what's expected.Some ESD foam I get from E14 measures 130K, tips ~25mm apart.#1687855http://nz.element14.com/multicomp/038-0016/high-density-foam-305x305x6mm/dp/1687855?exaMfpn=true&categoryId=&searchRef=SearchLookAhead&searchView=table&iscrfnonsku=falseIt's a Multicomp product #038-0016 and cheap.

author: metrologist
author_rank: Super Contributor
timestamp: April 21, 2017, 04:02:21 am
content: Quote from: blueskull on April 20, 2017, 09:33:04 pmI got loose parts floating in a bubble padded envelope, with some pins sticking out and folded over!

author: TheSteve
author_rank: Unknown
timestamp: April 21, 2017, 04:09:04 am
content: I've received fet probes just stuffed in a cardboard box from an ebay purchase, and when I bought a PGA pin Intel processor it was just stuffed in a cardboard envelope. I had to straighten 20+ pins but really it is a miracle it survived at all.