Chips pulled off dumped PCBs and then sold, due to the "chip shortage"? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: August 29, 2022, 10:13:36 pm
content: Hi,Due to the chip shortage, are there places where old scrap PCBs are haveing chips de-soldered from them, and then the chips cleaned up, and then sold on as new?

author: langwadt
author_rank: Super Contributor
timestamp: August 29, 2022, 10:21:58 pm
content: there's money to be made so of course there is, and it isn't new, the shortage just makes it more profitable

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 29, 2022, 11:04:43 pm
content: Quote from: Faringdon on August 29, 2022, 10:13:36 pmThat was happening way before the shortage, especially for things like phone & laptop parts for repairMore profitable now....

author: tom66
author_rank: Super Contributor
timestamp: August 29, 2022, 11:34:41 pm
content: We've had FPGAs pulled off scrap boards that are from our own production, because these FPGAs are worth £250 each greymarket (£50 normally)It's feasible to do this because removing and reballing a small BGA costs about £50. We use a small facility in Edinburgh to do this. But, normally the board would just be e-waste. These parts are only used internally, mind, for R&D or marketing units. We don't trust them enough to ship to customers.

author: MT
author_rank: Super Contributor
timestamp: August 29, 2022, 11:47:24 pm
content: Quote from: Faringdon on August 29, 2022, 10:13:36 pmChina 2011

author: nctnico
author_rank: Super Contributor
timestamp: August 29, 2022, 11:50:27 pm
content: Quote from: tom66 on August 29, 2022, 11:34:41 pmYep. Recently I wanted to have some boards made. The assembler even offered to take in old PCBs and re-use the components from those boards. I still can't make myself be happy with such a solution.For another project I did receive desoldered chips (sold as new) which I returned.

author: bdunham7
author_rank: Super Contributor
timestamp: August 30, 2022, 12:26:18 am
content: Quote from: Faringdon on August 29, 2022, 10:13:36 pmI'm sure some are trying, but it is tough to get away with selling them as new, unless you count on your customers being desperate and just overlooking the obvious signs of reuse. What does happen is that the chips are sold asusedto buyers that know this but then incorporate them in a product which then may be sold as new. This probably wouldn't be the worst thing in the world if it were done with extreme care--like a dehydrating bakeout before disassembly and again before going in the toaster--but most of this is just done quick and sloppy and just has to work well enough to get out the door. Obviously it is fraud if the product is sold as new, but I suppose there is a place for this for in-house or factory repair programs. For non-critical applications, of course.

author: magic
author_rank: Super Contributor
timestamp: August 30, 2022, 05:46:10 am
content: Quote from: bdunham7 on August 30, 2022, 12:26:18 amYes, it's called eBay

author: Black Phoenix
author_rank: Super Contributor
timestamp: August 30, 2022, 06:24:09 am
content: That's not new...Some listings from Xianyu app (Alibaba owned app for second hand items):

author: ryan_zheng
author_rank: Newbie
timestamp: August 30, 2022, 06:44:13 am
content: This is not something new but the global shortage definitely made such business grow.The company I used to work for has a batch of product made with some MCU in it, which was scrapped because newer firmware would not fit in the on-chip flash. It was the worst time for buying chips and the price of that particular MCU inflated by more than 20x, so they sold the chip to another company in urgent need of that chip and was willing to buy used chip, using an agent who took care of removing, cleaning up, testing and shipping of the chips.(FYI that customer makes non-critical consumer electronics, and from what I heard their manufacture tests suggest no increase in defective rate related to using those chips. The agent supposedly cut down the boards, baked them, took the chip off, vacuum packed with desiccant. They shipped those to the customer and instructed them to bake those chips before SMT.)As an EE myself I also have some connections who provide this type of service. Sometimes I would buy pulled chips for my own projects, as they are much cheaper. Like others have said, 闲鱼(Xianyu) is the main place for such transactions if you do not have your own contact. You can buy and sell chips, scrap boards and cut-down boards on the app.It was just part of the system, until people began to sell used chips as brand new. Those sellers would clean up the chip, re-badge the chip by sanding and lasering, and re-tape or re-tray with authentic T&Rs or trays. Some seller may even skip testing of the chips. That's where the bad reputation came from.

author: Faringdon
author_rank: Super Contributor
timestamp: August 30, 2022, 07:35:52 am
content: Thanks, from what kind contributants are saying, this is done, but eg, a "desoldered and cleaned up" 20TSSOP couldnt be cleaned up well enough to appear as new?Also, it makes you wonder about the ESD situation of it.

author: ryan_zheng
author_rank: Newbie
timestamp: August 30, 2022, 07:47:22 am
content: Quote from: Faringdon on August 30, 2022, 07:35:52 amIt can be done if they want to. A quick search on Taobao and I found "tin removing liquid".After using such liquid to remove all tin plating and solder residues, I imagine they can chemically tin the pins again to make it look brand new.Quote from: Faringdon on August 30, 2022, 07:35:52 amIf whoever wants so they definitely can put care into it. Otherwise yeah it may be less than ideal.

author: AndyC_772
author_rank: Super Contributor
timestamp: August 30, 2022, 07:53:18 am
content: It goes without saying that these chips have not been handled according to any ESD precautions; they will have been exposed to ESD events and most will have latent damage.That's not the worst thing in the world, though. The only reason to buy these recycled parts at all is desperation, and if what you really need is one or two microcontrollers so you can develop code at your desk ready for production that might be a year away, it's not the end of the world if a chip dies. Just make sure you have spares, and never let any of them outside an R&D environment. You can still develop good code on a flaky chip, and chances are you will come across a perfectly good one from time to time.Personally I'd be more concerned about them having had OTP memory programmed, or non-reversible code protection enabled. On an STM32, setting code protection level 2 means the chip can never be reprogrammed again using an external debugger. For all practical purposes it's scrap, and I can all but guarantee the vendor won't care.Also, if the brown-out reset voltage is set to a level that's above the supply voltage used on your board, it'll never exit the reset state. The chip is effectively dead unless you can increase the supply voltage and then reset the option bytes, and if you can't do that on your board, then it's useless.(Learn from my mistake, folks! The BoR voltage setting can easily catch you out when you migrate a design from 3.3V to 2.5V without changing the option bytes... you'll soon remember the first time you upload newly modified code from a previous hardware revision into a new platform!)

author: coppercone2
author_rank: Super Contributor
timestamp: August 31, 2022, 05:33:36 am
content: those parts soaked in tin removing liquid are dodgy as fuck. Think about it, you get a part that is soaked in some kind of acid after its been desoldered. There could be cracks in the plastic from the desoldering and previous use that have whatever tin removal stuff that is used go into the chip. those bond wires are really not that durable. And then you also have tinning liquid going on a bonded die chip.The stuff you get is tinned BEFORE the die is bonded. That means rigorous cleaning.I am not sure ESD is your primary problem anymore!I strongly suggest if you reuse parts, you just desolder them, clean them with alcohol and resolder them. I don't think you should be using any kind of chemical dips for cosmetic purposes.

author: Kasper
author_rank: Frequent Contributor
timestamp: August 31, 2022, 03:13:07 pm
content: It seems this has been a problem for years.Quotehttps://www.scientificamerican.com/article/the-pentagon-rsquo-s-seek-and-destroy-mission-for-counterfeit-electronics/Quotehttps://www.newscientist.com/article/dn19819-the-phoney-chips-that-could-cripple-military-tech/

author: Faringdon
author_rank: Super Contributor
timestamp: September 03, 2022, 11:28:21 am
content: Thanks,I also believe that at component vendors, when someone drops a $5 chip or it accidentally gets handled without ESD precautions...they then put those chips in the "do not sell to bona fide companys" box...and those chips only get sold to hobbyists like myself...who arent from a "genuine" company.... do you also concur with this?

author: Gyro
author_rank: Super Contributor
timestamp: September 03, 2022, 12:05:54 pm
content: Quote from: Faringdon on September 03, 2022, 11:28:21 amNo I don't concur.The UK reputable distributors dump them in a white expanded polystyrene box labelled 'treez' and wait for you to order something. All the rest of us get genuine, properly handled parts.The China Ali, ebay etc. sellers can't pronounce 'treez' [Edit: or 'Faringdon'], so send you the same fake / salvaged crap that theywould havesent to the rest of us if we had taken that path.

author: nali
author_rank: Frequent Contributor
timestamp: September 03, 2022, 12:40:50 pm
content: I'm just waiting for the inevitable fresh thread: My flaky design keeps blowing up and I don't know why so it must be dodgy components...

author: Black Phoenix
author_rank: Super Contributor
timestamp: September 03, 2022, 03:07:03 pm
content: Quote from: Gyro on September 03, 2022, 12:05:54 pmReally, he is still around here? But with a different nick? I was finding strange not seeing his stuff but since I've been out for some months it was expected. But now this?

author: Stray Electron
author_rank: Super Contributor
timestamp: September 03, 2022, 03:25:08 pm
content: Quote from: Faringdon on August 29, 2022, 10:13:36 pmNot necessarily "As New" but it's a common practice in electronics repair industry and has been for a very long time. It's the only way that repair companies can get some obsolete IC and other devices (aka "chips"). One of my friends owns a company that does this and he's been doing it for as long as I've know him, over 25 years at this point. They routinely pull socketed chips (sold as "socket pulls") and depending on the demand and the value, they might even unsolder chips (sold as "solder pulls").I recently bought four LM399s from him and they were used but worked perfectly.

author: rsjsouza
author_rank: Super Contributor
timestamp: September 03, 2022, 06:22:02 pm
content: There's nothing really wrong with used parts; people have been reusing those in repair since the dawn of electronics. The practice of "rebranding" parts into more modern (and more expensive) models is also quite old as well - I remember in the 1980s how many old Germanium or otherwise underspeced power transistors were being remarked as powerful 2N3055s or BU208s, to the despair of the hobbyists and technicians.

author: tooki
author_rank: Super Contributor
timestamp: September 03, 2022, 06:53:38 pm
content: Quote from: Black Phoenix on August 30, 2022, 06:24:09 amI don’t mind that at all: they’re being very clear that the chips are salvaged. They’re not trying to pass them off as new.

author: Faringdon
author_rank: Super Contributor
timestamp: September 03, 2022, 07:51:11 pm
content: Chips like UCC28070A are TSSOP20 and such small parts are ultra ESD sensitive....also, in the UCC28070A datasheet it gives a severe ESD warning about the chip.I dont think chips like this are meant to be handled, solder pulled, or anything like that.....but i bet its going on.

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 03, 2022, 08:02:57 pm
content: Quote from: langwadt on August 29, 2022, 10:21:58 pmYep, there's been a constant stream of those on Aliexpress and the like for years. There's just even more demand now.

author: Gyro
author_rank: Super Contributor
timestamp: September 03, 2022, 08:32:22 pm
content: How did I know that one was coming?Quote from: Faringdon on September 03, 2022, 07:51:11 pmESD sensitivity is a function of the Silicon, not the package.QuoteWell, it states the standard JEDEC HBM and CDM ESD ratings, like any other modern devce, if that's what you mean.QuoteIf they not meant to be handled, it's going to give you a bit of a problem getting them onto your board isn't it? Youarethe weakest link. As for solder pulls, that depends on where you source your parts from. You won't get solder pulls if you buy from a main distributor with proper traceability back to the manufacturer. If you chose to source them from somewhere dodgy then that's your funeral.

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 03, 2022, 08:42:41 pm
content: Quote from: Gyro on September 03, 2022, 08:32:22 pmWell, to be completely fair, there is some impact of the packaging on the consequences of ESD. Typically internal wiring (bonding) between silicon pads and the outside legs introduces a small series inductance which will filter out ESD to some extent. This extent being, in practice, ridiculously small.While there is some subtle (read: subtle) difference between a large DIP package and a small SMD one, the difference between say a SOIC package and a TSSOP is like uh. You guessed it.

author: Faringdon
author_rank: Super Contributor
timestamp: September 04, 2022, 07:42:48 pm
content: QuoteThanks for this.This is the key point.A DIP is significantly less ESD susceptible than a TSSOP (ie, a small SMD one). We agree there.So you would also extrpolate that a SOIC20 was also fairly significantly less ESD damage susceptible than a TSSOP20

author: langwadt
author_rank: Super Contributor
timestamp: September 04, 2022, 08:49:27 pm
content: Quote from: Faringdon on September 04, 2022, 07:42:48 pmis a tiny risk times a random number pulled out of someones rear end fairly significant?

author: Gyro
author_rank: Super Contributor
timestamp: September 04, 2022, 09:05:00 pm
content: Quote from: Faringdon on September 04, 2022, 07:42:48 pmWhat part of subtle don't you understand? Do the words that people write actually penetrate your internal monologue?

author: rsjsouza
author_rank: Super Contributor
timestamp: September 04, 2022, 10:23:41 pm
content: Packaging has very little to do with ESD susceptibility. A TO220 MOSFET is almost guaranteed to blow if improperly handled.As Gyro and others have said, ESD depends on the silicon inside the package, not its size, pin spacing, color, shape, thickness, etc.