Counterfeit semiconductors?

[tronixstuff]

Is there the possibility of counterfeit semiconductors? It just seems that some sellers on eBay are way too cheap... for example, the Intersil ICL7107 - 5 for US$10 delivered from China, but the official Maxim sell price is over US$3 for lots of 1000 or more... does anyone have any thoughts on this? Thanks.

 

[Electronworks]

Yes definitely. I have had experience of well known electronics manufacturers (including products you find in the high street) coming foul of counterfeit semiconductors. Some parts are just the package with no silicon inside, some are test escapes.

Contract manufacturers normally have good supply chains, but in times of long delivery, they sometimes buy from the 'grey market' where the source of the components is uncertain. Most of the time they don't get burnt, but when they do it can be costly.

Counterfeiting is a bit problem in the industry and although the Far East has many low cost very credible businesses, it can also be the place where most counterfeiting originates.

 

[tronixstuff]

Yes definitely. I have had experience of well known electronics manufacturers (including products you find in the high street) coming foul of counterfeit semiconductors. Some parts are just the package with no silicon inside, some are test escapes.

Contract manufacturers normally have good supply chains, but in times of long delivery, they sometimes buy from the 'grey market' where the source of the components is uncertain. Most of the time they don't get burnt, but when they do it can be costly.

Counterfeiting is a bit problem in the industry and although the Far East has many low cost very credible businesses, it can also be the place where most counterfeiting originates.

Crikey... I'm glad I didn't order them from ebay then. Nothing seems to be sacred from the counterfeiters anymore. Will stick with farnell or rs and pay the extra.

 

[tvtech]

RS Components FTW.

Premium price, Premium products. Expensive but the answer.

As a sideline, I design PCB's for customers. I use RS Components parts as my reference. If RS supplies you with a part.....you know it's the genuine thing.
Not some cheap Chinese fake look-alike.

Once the board design is complete and populated with RS components I sign it off. Customer sees it is working and up to design specs...

What the customer chooses to do after that is his/her problem.

Continue using RS/source quality components or use Chinese?

Simple answer. They go the Chinese component route for mass production. No problem for me. I have been paid. My job is done.
Component failures are not my problem.

The PCB design is sound.

Cheers

 

[bychon]

I met a batch of Mexican transistors. 2n3055's...allegedly. I had to design a test fixture to weed out the ones that punched through when voltage was applied. 40% of the batch was bad.

 

[tvtech]

Being physically "hands on" in this industry for way too long soo much comes to mind.......

There are chancers everywhere.

I have seen it with BU208D. Fake Thompson rehash (silver face). I have seen it with Toshiba (same thing).

My supplier ATM has secured BU508AF and BU508DF originals from Toshiba.

AF for PSU and DF for Line stage. What a pleasure.

These 508's work anywhere. IF they are built on original specs.

Cheers guys

 

[Thunderchild]

I met a batch of Mexican transistors. 2n3055's...allegedly. I had to design a test fixture to weed out the ones that punched through when voltage was applied. 40% of the batch was bad.

I heard that those paerticular model of transitor was a very popular part number to slap on any old transistor of dubious origin. I read an article about an amp kit and they said that because of the issues with counterfeits they did use the obvious choice of the 2N3055.

It is something I have wondered about having just bought 150 mosfets from china for 40 pence each, but they sell from RS/farnell for 80 pence anyway so I think the supply chain and RS overheads can easily account for that (I hope )

 

[tvtech]

Hope all goes well Thunder.

China Mosfets are dubious. In fact, anything from China is dubious. Too cheap.

Cheers

 

[Thunderchild]

well I have a cracking oscilloscope off ebay from china very cheap, infact now that I have software modded it has twice the bandwidth, at the end of the day it is all made in china and to assume that stuff is actually checked when imported is to be an ass. in the case of semiconductors you probably are safer with RS but then you can buy the same mosfet from RS at 50 p or 100p, now you tell me the difference ? and I'm not talking about the difference between bulk rpices and single parts

 

[tvtech]

Too new to argue here. I will be back tomorrow.

Cheers folks...

 

[Hero999]

Buying cheap stuff off ebay is often a gamble: sometimes it's worth it, other times it's not.

All I'd say is if you buy cheap stuff off ebay, don't push it to its maximum ratings, for example, if you buy some LM7805s use them for low currents up to 500mA, don't operate them off load (I've heard some LM7805s don't like it) and don't expect the drop-out voltage to be any less than 3V, in short always assume the worst characteristics on the data sheet.

 

[Vizier87]

What a shame that I'm a Chinese and I don't like China's style when it comes to their industry.

 

[Sceadwian]

I'm an American, and I don't like the way the US approaches industry either =) If you ask me the heavy handed unions here aren't much better than the all powerful controlling government there.

 

[Thunderchild]

same for UK industry, we have a few leaking "charged air coolers" that my works manager wants to use anyway (for a military customer), they only leak like hell !

 

[shokjok]

eBay sellers are invisible. You can't sample the product, see its datasheet or MSDS or pamphlet, touch it, try before you buy, or look up its equivalent devices from the device markings. How do you know if the seller gives you the original or the fake device, and if their "limited time offer" does not reappear later?

 

[Thunderchild]

eBay sellers are invisible. You can't sample the product, see its datasheet or MSDS or pamphlet, touch it, try before you buy, or look up its equivalent devices from the device markings. How do you know if the seller gives you the original or the fake device, and if their "limited time offer" does not reappear later?

all true. what bugs me is why RS and Farnell have 3-5 listings for the same parts with prices ranging from £ 0.5 to £ 2.5

 

[tvtech]

I trust RS absolutely. Never had a problem with any of the parts I have ordered from them.

I don't know Farnell. So I canno't comment on the way they run their business.

On the TV repair side, we buy 99% of our components from a hugely trusted supplier called Screenvision. They know the business and we have had very few problems with what they supply. Their prices for TV spares are realistic and they supply spares that work to spec. 99% of the time.

The PCB side is another story.

Here you are in a designing and not repair environment. You design a board. Customer needs to see it working. You have to rely on some form of standard.
RS provides that with the products they sell. For example: BC337-40 is what they advertise on their Website. BC337-40 is a high gain version of a "normal" BC337.

Customer specs. are a BC337-40.

Go Chinese for your BC337-40. They will sell you a standard BC337. Design failure. Board won't work. Customer won't pay.

I could go on and on and on.

Till next time.

 

[Hero999]

It depends on the application.

If you design the circuit to use a cheap generic transistor and will work providing the gain is over 100 or so with a collector current of 5mA, it'll work with most transistors enabling you to buy cheap. If you know that that particular transistor needs to at least have a certain gain at a certain collector current, then you need to be far more picky.

 

[tronixstuff]

I will stick with Farnell, RS and large volumes sometimes from Digikey. Think paying a bit more is worth the peace of mind than taking the eBay gamble.
A saying springs to mind: "quality is remembered long after price is forgotten"

't

 

[Thunderchild]

A saying springs to mind: "quality is remembered long after price is forgotten"

't

I usually work by that, I may have been a bit hasty buying 150 but at least for that price I can compare them to buying lower spec parts from RS. the point is RS (and the others) have to pay staff to run a company (in european wage terms), they have to research supliers, hopefully test samples they get and market them on a website that cost them money to run, they then have to run warehouses to keep this tuff in stock so that it is available at a moments notice (and often thwey do run out), warehouses that require rent and tax paying and bills along with staff wages.

Then you get the man on ebay who lives in china/thailand who lives round the corner from the same manufacturer as the one RS uses, he bulk buys, takes them home, puts them on ebay a website that costs him nothing until he makes the sale and then sends them off, and at the same time paying himself a wage in terms of standards in china. I'm sure you can get a reputable ebay seller in china to easily undercut large suppliers like RS, but then you have to trust him, with RS they are a huge company with a quality system and a reputation so they play it straight most of the time, the chinese guy can just cancel his account with ebay and get another one if he gets into trouble