What's inside the cheapest and fakest jellybean opamps

[magic]

Try a metal container. A small steel cup (30ml are available here) or even a thimble.

[prosper]

Interesting thread. I have a tray of various cheap chinese opamps, and so far as I can tell none of them are fakes, at least parametrically. The 324's go down to ground and up to about Vcc-2V, with typical 324 output quirks (can only sink a tiny current, and need a 10k pulldown resistor to get down to 0V output when sourcing current, etc) and crossover blips, GBW and slew appear to be on the money, input offset are within norms, etc. Same for the 358's, TL072's, MCP6002's, etc. Maybe I lucked out? Some are obviously re-claimed silicon, but, all that I've tested appear to function to datasheet specs.

How were you able to ensure you were going to get fakes? What are the warning signs? Price? (I think I paid $1 for 50 SOT LM358's, that seem to perform as expected)

[magic]

I look at price and photographs. Those Chinese DIP packages simply looks slightly differently than Western ones (photo in the first post). Then, once I identify a few auctions with fake and authentic chips, it's possible to get a feel of what the pricing is and guess what those without photos could be. Sometimes it's helpful to look at other offers from the same store. There are some vendors who reliably deliver pulls IME and others who look like 100% LM358 under the hood.

IIRC it's something like 10~20 cents in small quantities (≤10) for harvested DIP8 chips on Ali, or more if it's rare and in demand.

Very cheap 358/324 may be one of those Chinese implementations. Who knows, they may be good. But if you buy TL072 for the price of the cheapest 358, well, that may be risky.

I hoped to find some Chinese clones of TL072 or NE553x but ended up with nothing but rebranded 358/4558 and a few recycled 553x for slightly higher price.

[yunLad]

Hi! Got some terrible quality mildly interesting die shots.

After finding out aliexpress cheapest TL074'nt (324 clones they are, 0.9×0.7mm marked 324n24) I decided to decap LM324s from 2 different vendors. One from the TL074'nt vendor is surprisingly a different 324 clone, this time marked "658" (or "859") on a slightly larger die (0.9×0.9mm)

The other one was much more interesting, containing two separate 0.8×0.5mm 358ish dies that almost look to be on a digital node. Couldn't see any marking. Photos are terrible but maybe someone can figure out what's going on there.

[magic]

Smartphone and a webcam lens for macro?
This stuff has potential, but it needs more light.

For my lousy photograph of fake OP07 which you have probably seen in the other thread, I made a small PCB with a hole in the center for the lens to look through and four miniature SMD LEDs around it.

For the photographs in this thread, I placed the chips on a transparent box and mounted a 5mm LED inside the box, at some distance below the IC and pointing up. That way the light is coming from behind the IC and reflects off the optics. More on this technique here:
https://www.eevblog.com/forum/projects/decapping-and-chip-documentation-howto/

The other one was much more interesting, containing two separate 0.8×0.5mm 358ish dies that almost look to be on a digital node. Couldn't see any marking. Photos are terrible but maybe someone can figure out what's going on there.

This is awesome
Now I want one too

I don't know if there is anything special about this particular 358. Such stripe patterns are common on CMOS chips, but in this light it's hard to tell, they could simply be bipolar power transistors with multiple fingers.

[yunLad]

Smartphone and lens from an old optical drive, propped up on tweezers, focused by balancing a small weight on the display. It's terrible Muriel. Thanks for the reflection-lighting idea! That may work since mi was just flooding it with side light due to short focal distance. If that fails I may be able to get access to a proper microscope but unfortunately not untill january.

[EPAIII]

What I do not understand is why anyone would buy such trash. When I buy electronic parts, I go to suppliers who have a real brick and mortar presence and who have been around for many years. Sure, I compare prices, but not with those who don't even need to fly-by-night because you can't find out where in the world they actually are.

Is the situation so bad in some areas of the world that people must go to such suppliers (I hate to even use that name for such sources)? Or is it an attempt to go to the lowest price possible in order to get some of the business that has been taken by the Chinese suppliers with their impossible prices? You can't compete with them on the basis of price. You should try quality and service instead.

[magic]

It's mostly beginner hobbyists falling for those auction site deals.

Familiar platform, no MOQs, cheap shipping, what's not to like?

[Conrad Hoffman]

I don't understand the economics. It's hard to believe there are enough beginner hobbyists to make selling cheap junk parts worth the effort. If you have the equipment, there just have to be more profitable things to do with it.

[Noopy]

One way is to take parts that were scrapped after manufacturing and sell them. Costs you nothing (if you are near the trash bin):
https://www.richis-lab.de/REF06.htm (scroll down a bit)

Another way is you take rubbish, desolder (for example) every DIL-8 sort them by opamps or not, rename them with *cost-a-lot* and sell them.

One hour of work costs nothing in china...

[magic]

I don't understand the economics. It's hard to believe there are enough beginner hobbyists to make selling cheap junk parts worth the effort. If you have the equipment, there just have to be more profitable things to do with it.

That's why I think it's an industrial effort piggybacking on China's industrial infrastructure.

The dice could be normal products designed as cost-effective substitutes for standard Western parts and fabbed in millions for the domestic market. They tend to work, maybe with reduced max power dissipation or some questionable spec, but still acceptable in a ton of applications, particularly if you know what they are and have the vendor's datasheet.

Packaging in DIP is a bit uncommon as the industry uses 100% SMD but not a big deal for an occasional order because DIP is still alive and there are businesses doing it.

The creative wirebonding jobs (dual die with single pinout, two dice in quad package) may be the biggest cost factor, but manageable at scale since it's just a matter of reconfiguring some machine.

Printing TL074 and fake TI logo costs no more than any other marking.

You end up with a product which is cheaper than recycling and halfway between a legit Western LM324 and a legit Chinese LM324, which nobody in the West would buy. And they sell in thousands on auction sites all over the world.

Recycling is still a thing in higher end and low volume ICs. Something like voltage reference - sure. Even NE5532 is a mix of recycled chips and pristine "CN4558" with fake markings IME.

[EPAIII]

I don't know if it is all hobbyists. I frequent a machining BB and there are professional guys there (machinists) who often need to repair a piece of electronic equipment. CAM (computer assisted machining) or servo systems or whatever. Often these broken items are both old, like 20 years or more and no longer supported by the OEM. Of course they tend to use older electronic technology. And when they break, they are absolutely needed for the Xyz order that is due to be delivered yesterday. So they are stuck with repairing them.

Now, these guys would not think twice about spending several hundred dollars for a cutting tool, but they may have a boss or bean counter looking over their shoulder and counting every other penny. And they are not familiar with electronic part sources other than Radio Shack, which is now gone. So they do an internet search and a good electronic supply house is on page three of the results with Amazon or one of the sellers there on page one.

Part number looks right. Manufacturer looks right. It has the right number of legs. BUY IT!

Of course, I call them to task over this and often suggest better sources, but it does no good.

I can imagine that there must be others in other professions who are pressed, probably kicking and screaming, into electronic maintenance by circumstances. Musicians are another group that I have encountered in these situations.

I don't understand the economics. It's hard to believe there are enough beginner hobbyists to make selling cheap junk parts worth the effort. If you have the equipment, there just have to be more profitable things to do with it.

[Terry Bites]

[Someone]

Another way is you take rubbish, desolder (for example) every DIL-8 sort them by opamps or not, rename them with *cost-a-lot* and sell them.

One hour of work costs nothing in china...

and sell the customer the same model of cloned IC tester that was used to "verify" the part 

[Noopy]

That is a really good idea!