Should ICs always be packaged in ESD safe bags? - Page 1
Forum section: electronics / general

author: DTJ
author_rank: Super Contributor
timestamp: July 24, 2017, 07:30:14 am
content: I got some ICs from RS and they appear to be in a plain old PE plastic bag rather than the expected metalised foil or even the non-ESD generating pink plastic bag.I'd assume RS know what they are doing.Are some ICs sufficiently immune to ESD to be packed like this?

author: Ian.M
author_rank: Super Contributor
timestamp: July 24, 2017, 07:50:04 am
content: RS product page:http://uk.rs-online.com/web/p/temperature-humidity-sensors/8937118/If you look in the datasheet you'll find it has a 4KV ESD rating (HBM). That puts it in class 3A of ESD STM5.1-1998. There's only one class less sensitive: class 3B (>8KV HBM ESD rating).

author: wraper
author_rank: Unknown
timestamp: July 24, 2017, 08:51:09 am
content: That bag may be ESD dissipative. If it was inside another ESD shielding bag, it might be OK. Otherwise it's not.Quote from: Ian.M on July 24, 2017, 07:50:04 am4kV HBM rating is not much at all. Rarely any IC goes below 2kV HBM.FYI there is alsoIEC 61000-4-2 level 4:– 15 kV (air discharge)– 8 kV (contact discharge)8kV contact discharge is way stronger than 8kV HBM. 10kV HBM is weaker than 2kV IEC 61000-4-2https://www.onsemi.com/pub/Collateral/TND410-D.PDFQuote

author: Ian.M
author_rank: Super Contributor
timestamp: July 24, 2017, 09:09:46 am
content: System level ESD testing standards are totally irrelevant for a loose IC before its soldered to a board.However I wouldn't entirely trust RS components' choices for individual part or small multipack packaging when it comes to ESD sensitivity. Historically, I've seen quite a few logic chips and similar ICs that they've repackaged in packages that don't appear to offer any ESD protection whatsoever.

author: wraper
author_rank: Unknown
timestamp: July 24, 2017, 09:30:05 am
content: Quote from: Ian.M on July 24, 2017, 09:09:46 amDidn't you know that HBM test is not done on a bare IC as well?EDIT: BTW many parts claim IEC 61000-4-2 compliance at the component level.Like this HDMI switch:http://www.ti.com/lit/ds/symlink/tmds361b.pdfQuoteYou said:QuoteBy this you made a false impression this is nearly as robust device as you may get while in reality it's not.

author: Ian.M
author_rank: Super Contributor
timestamp: July 24, 2017, 10:00:57 am
content: Quote from: wraper on July 24, 2017, 09:30:05 amIt may not be industry best practice but the manufacturer's datasheet for the O.P's chip (TSYS01) specifies its ESD sensitivity in terms of the HBM test applied pin-to-pin.

author: wraper
author_rank: Unknown
timestamp: July 24, 2017, 10:15:29 am
content: Quote from: Ian.M on July 24, 2017, 10:00:57 amIt means they put the current between pins. They do connect it to the circuit, not just strike it free floating, which was the point of my post.

author: wraper
author_rank: Unknown
timestamp: July 24, 2017, 10:33:00 am
content: To better word it, by bare IC I was meaning IC by itself, without a circuit connected. Connection to the test circuit is not necessarily is done by soldering. The same applies to both HBM and IEC 61000-4-2.

author: DTJ
author_rank: Super Contributor
timestamp: July 24, 2017, 10:41:47 am
content: Quote from: Ian.M on July 24, 2017, 07:50:04 amOk I guess that explains it.I looked in the data sheet and saw the 4kV ESD rating but without the required knowledge it did not help me.It wasn't in any other packaging - just the usual white paper bag stuffed full of parts.

author: wraper
author_rank: Unknown
timestamp: July 24, 2017, 10:49:41 am
content: Quote from: DTJ on July 24, 2017, 10:41:47 amNo it doesn't. It's still remains an ESD sensitive part with all handling precautions still applying.

author: DTJ
author_rank: Super Contributor
timestamp: July 24, 2017, 10:51:42 am
content: Quote from: wraper on July 24, 2017, 10:49:41 amOf course normal handling precautions apply.

author: wraper
author_rank: Unknown
timestamp: July 24, 2017, 10:54:38 am
content: My guess would be that some idiot had read that it is a temperature sensor (like PTC, NTC, RTD) and entered into their system as it is handled it as such. Without noticing the fact it is IC and ESD sensitive.

author: wraper
author_rank: Unknown
timestamp: July 24, 2017, 11:03:59 am
content: Somewhat related. I have received some moisture sensitive parts from RS. There was no any moisture sensitive bag, desiccant, humidity indicator card or MSL marking and shelf life before baking required on the package. On the contrary, Farnell and Mouser have always done this properly. Even TME with their not so perfect handling practice do this as well.

author: DTJ
author_rank: Super Contributor
timestamp: July 24, 2017, 11:22:54 am
content: Quote from: wraper on July 24, 2017, 11:03:59 amI had wondered the same about it being treated as a sensor. The manufacturer (TE) seem to refer to it as a TSYS01 in all their data sheets and documentation. I didn't think RS sold them as searching for TSYS01 in their system returns no hits. Previous stock was from a smaller company and they supplied them in a cut down ESD tube in an metalised bag.Farnell are also good in that they'll 'minireel' a lot of semis for no fee.

author: wraper
author_rank: Unknown
timestamp: July 24, 2017, 11:30:53 am
content: Quote from: DTJ on July 24, 2017, 11:22:54 amAFAIK it's no longer the case. They reduced minimum quantity required but introduced a fee.

author: DTJ
author_rank: Super Contributor
timestamp: July 24, 2017, 12:36:34 pm
content: Quote from: wraper on July 24, 2017, 11:30:53 amah ok, bummer. Worked for me 3 months ago.

author: madires
author_rank: Super Contributor
timestamp: July 24, 2017, 12:52:59 pm
content: Doesn't each ESD event have the potential to weaken the ESD protection?

author: wraper
author_rank: Unknown
timestamp: July 24, 2017, 02:06:28 pm
content: Quote from: madires on July 24, 2017, 12:52:59 pmYes it does. HBM uses only one pulse of each polarity. But IEC 61000-4-2 test uses minimum 3 pulses of each polarity because damage can accumulate until part fails.Quote