Are diodes, zener diodes, and bridge rectifiers ESD-sensitive parts? - Page 1
Forum section: electronics / beginners

author: sokoloff
author_rank: Super Contributor
timestamp: April 18, 2016, 04:55:10 pm
content: Placed an order from Newark for a few RPi3s, some capacitors to have on-hand and to try my hand at repairing a few power supplies I've accumulated over the years, and as such, I also bought some power supply standard components.What surprised me was that *some* (not all) of the Zener and standard diodes (and the bridge rectifiers) came packed in the ESD bag (fairly normal), but also came packed in the cardboard box about the size of two decks of playing cards, with foam packing, and prominent ESD-sensitive component warning stickers. Some of the other, seemingly nearly identical, parts just came in the plastic ESD bags.I will keep them in the boxes they came in until needed, but it would have never occurred to me to worry much about diodes and ESD. Is Newark being overly cautious here, or am I under-informed of the danger?Thanks!

author: mazurov
author_rank: Frequent Contributor
timestamp: April 18, 2016, 05:12:47 pm
content: It's quite likely that whoever packed them for you was not very aware of properties of different parts:-). Also, they could be out of regular bags.

author: Kleinstein
author_rank: Super Contributor
timestamp: April 18, 2016, 05:15:28 pm
content: Zener diodes and bridge rectifiers are normally not ESD sensitive. The same is true for larger diodes (e.g. 1N400x) - but special low leakage fast diodes / schottkys can be ESD sensitive. Also modern LEDs and especially laser diodes are ESD sensitive.Sometimes the distributors send parts in ESD bags even if not sensitive at all - I got BNC connectors and big electrolytic caps in ESD bags. But I also got small MOSFETs (e.g 2N7000 like) in more or less normal plastic bags from a different source.

author: German_EE
author_rank: Super Contributor
timestamp: April 18, 2016, 07:08:11 pm
content: One other way of looking at it, send every part in an ESD bag and that way you don't need to train your staff in what's ESD sensitive and what isn't.

author: starphot
author_rank: Contributor
timestamp: April 18, 2016, 07:56:51 pm
content: I worked for a consumer electronics retail company in their regional repair department for nearly 20 years. We ordered parts from the in-company national parts department. The CMOS parts first came with the individual black conductive foam. Then they came in the little non-ESD foam blocks. We complained to the parts department and they replied that these new parts came in the ESD tubes. They then re-packed all of the semiconductor parts in ESD bags or the ESD black foam. Better safe than sorry? Well, then I ordered the memory coin cell batteries with leads for memory in certain scanner and ham radio units and got them in in a plastic bag and the leads were jabbed in the black ESD foam and the contents were warm. I showed the bag unopened to my manager and asked him "What's wrong with this picture?" He growled and had an animated phone conversation with national parts.Joe

author: danadak
author_rank: Super Contributor
timestamp: April 18, 2016, 08:01:04 pm
content: Everything is ESD sensitive, including BNC conectorActually anything that can leave a carbon track from a burn from ESD will compromise HiZconnections you may be trying to rely on. Think like an electrometer. Think Teflon insulatingfeedthru connectors, whose environment over time collects a film of whatever is in the air ?Fish fry, pizza with peperoni, fried chicken........http://www.electrostatics.net/ESD_Guide/technical/ESD_sensitivity.htmRegards, Dana.

author: Zero999
author_rank: Super Contributor
timestamp: April 18, 2016, 08:30:58 pm
content: Quote from: danadak on April 18, 2016, 08:01:04 pmThat list is interesting. It says film resistor but doesn't mention the type or value. A 1210 package component will be more tollrant of ESD than a 402 component.As far as connectors are concerned: you'll need a fair bit of energy to char a teflon connector.

author: bson
author_rank: Unknown
timestamp: April 18, 2016, 08:41:43 pm
content: Most likely their database contains packaging information for customer ship, and the warehouse gets packing info along with the parts manifest. The information in the DB likely is based on what they get from the manufacturer. If absent it probably just defaults to an ESD bag, even for parts like connectors that "obviously" aren't ESD sensitive in the slightest. Or they simply don't use non-ESD bags because the cost of keeping both and the risk of the warehouse staff accidentally using the wrong one exceeds the savings. Or, the warehouse staff when out of ESD bags may decide standard bags are just as good and ship everything using them!A foam ESD box likely is just a DB error.I was surprised my last order of BUF602's came in a box in a bag with a humidity and age statement... But the THS3202DGN's didn't.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 19, 2016, 02:07:00 am
content: Semiconductors generally get ESD bags, whether it's needed or not. Cheap enough protection.Tim

author: VK5RC
author_rank: Unknown
timestamp: April 19, 2016, 03:28:36 am
content: I can never make any sense of the packing of the electronic supply companies, recently 30 8 pin DIL ic sockets arrived in a plastic tube, about 50cm long! Needless to say the courier bent the package, buggering up (technical term) 2 ic sockets. It would have been better if they were in a plastic bag.I suspect the guys that pack don't get much time to pack each one, so what is at hand, gets used.

author: TimFox
author_rank: Super Contributor
timestamp: April 19, 2016, 01:17:37 pm
content: Quote from: danadak on April 18, 2016, 08:01:04 pm

author: electr_peter
author_rank: Unknown
timestamp: April 19, 2016, 07:16:37 pm
content: Quote from: TimFox on April 19, 2016, 01:17:37 pmESD (Electronic Static Discharge) could hardly take out stainless steel bolt, but ESD (Energy Stored Discharge, i.e. explosive) certainly can... Be aware of actual abbreviations used, errors in vocabulary can be serious in some industries.