Warning- LM317K duds from Digikey

[David Aurora]

5 pages

I think you have confused me with 10 quadrillion other people who also doubted your competence, but appear to be convinced by thm_w's post at last, for some reason.

Same end result whether or not you and a couple of your buddies doubted my competence- I was right. Maybe you should spend less time mis-judging other peoples competence and more time reflecting on why you feel the need to do that.

[thm_w]

Its definitely silver color, so silver or aluminum. If you are saying aluminum doesn't glow then it would have to be silver.
https://tanaka-preciousmetals.com/en/products/detail/bonding-wires/

There isn't a ton of space on the die for larger wire. But maybe slightly thicker gold wires, and shorter length would have been OK.

[wraper]

Its definitely silver color, so silver or aluminum. If you are saying aluminum doesn't glow then it would have to be silver.
https://tanaka-preciousmetals.com/en/products/detail/bonding-wires/

There isn't a ton of space on the die for larger wire. But maybe slightly thicker gold wires, and shorter length would have been OK.

There is a space for thicker wire and unused in/out pads for a second wire in parallel. Silicon die looks like pretty normal LM317 die, maybe a little smaller than others shown but still of reasonable size.

[bdunham7]

Its definitely silver color, so silver or aluminum. If you are saying aluminum doesn't glow then it would have to be silver.
https://tanaka-preciousmetals.com/en/products/detail/bonding-wires/

There isn't a ton of space on the die for larger wire. But maybe slightly thicker gold wires, and shorter length would have been OK.

From that website apparently palladium-coated copper is a low-cost alternative to gold as well. 

There's room for more wires, right?  And it looks to me like you could double the diameter of the wires as well, although I'm no bonding expert.

[floobydust]

There is a space for thicker wire and unused in/out pads for a second wire in parallel. Silicon die looks like pretty normal LM317 die, maybe a little smaller than others shown but still of reasonable size.

It would interesting to measure and compare the die sizes.
To me it looks like the usual aggressive die shrink- resulting in the bonding-wire pads being tiny. Problem is you do that over many generations and hit a limit.
Compared to the pics here of other makes, there is no room for thicker wire. That means you'd have to use a second wire (input) and I see the die has provision for that but it would be hairy routing because the second (output) wire is in the way.
I'm guessing this is the 1.5A version die, not usable for the lesser current 317 versions if the sense resistor can be fuse modified.

[Siwastaja]

Same end result whether or not you and a couple of your buddies doubted my competence- I was right. Maybe you should spend less time mis-judging other peoples competence and more time reflecting on why you feel the need to do that.

You definitely were right.

I'm still enjoying my mental image of you contacting Digikey and their engineer as a very first thing asking for a schematic and parameters of your test circuit. Are you going to continue your one-man war and generate 6 pages of worthless email, or, do you suck it up, accept your loss, and use 5 minutes to draw that schematic, which you could have done here in the first place if your ego allowed you to operate like a normal sensible engineer?

Anyway, great job. I actually enjoy reading troll threads. And you definitely were right, just like a high-quality troll should be certain about before they start, so that they can do that nice ending reveal. Incompetent you are not - just an asshole who enjoys social games over being clear and concise.

[floobydust]

Same end result whether or not you and a couple of your buddies doubted my competence- I was right. Maybe you should spend less time mis-judging other peoples competence and more time reflecting on why you feel the need to do that.

You definitely were right.

I'm still enjoying my mental image of you contacting Digikey and their engineer as a very first thing asking for a schematic and parameters of your test circuit. Are you going to continue your one-man war and generate 6 pages of worthless email, or, do you suck it up, accept your loss, and use 5 minutes to draw that schematic, which you could have done here in the first place if your ego allowed you to operate like a normal sensible engineer?

Anyway, great job. I actually enjoy reading troll threads. And you definitely were right, just like a high-quality troll should be certain about before they start, so that they can do that nice ending reveal. Incompetent you are not - just an asshole who enjoys social games over being clear and concise.

To blame the application circuit over a melted bonding wire is totally hilarious.
I think you enjoy being the asshole here. Your trolling is fine if you are correct as the know it all.
But you blow up and personal attack too quickly to work out and hear any discussion. This makes the forum a hostile place and derails threads. PFO.

[wraper]

To blame the application circuit over a melted bonding wire is totally hilarious.

First 1/3 of this thread was basically: "this IC is garbage, trust me bro", and irritation when asked for more info. Nobody knew what was actual failure mode and conditions when it failed.

[floobydust]

Is this blaming the victim? New IC fails -> gimme full schematic -> no -> flames -> you are to blame -> flames

More worriesome is that we can't have a reasonable discussion on eevblog without the insults and personal attack.

[magic]

You got it wrong.

IC fails -> gimme basic details -> no -> how can we know that you are not to blame -> flames

Go back to page 1 and see for yourself.

[Analog Kid]

From my vantage point, the two bad guys here most responsible for muddying the waters are @magic and @wraper.

The OP has done everything that's required of someone making a report on defective parts. You nagging ankle-biters have no case.

More popcorn!

[wraper]

The OP has done everything that's required of someone making a report on defective parts. You nagging ankle-biters have no case.

More popcorn!

Read first 2 pages, zero info other than: "this IC is trash, other ICs are good, I've done everything correctly". Asking for more info: "how dare you question me!" You may notice that when OP provided some info about the part, conversation suddenly became constructive.

[magic]

Aluminum melts before it glows.

Aluminium definitely glows before it melts.


Sorry for the noise, this had to be investigated

[Analog Kid]

Aluminum melts before it glows.

Aluminium definitely glows before it melts.
(Attachment Link)

Sorry for the noise, this had to be investigated

Or maybe it glows as it melts?
How many angels can dance on the head of a pin?
Sheesh.

[magic]

Or maybe somebody is trolling due to having nothing meaningful to say.

[Analog Kid]

OK, so maybe it glows before it melts. (At least in some cases.)
Yay for you.

[bdunham7]

Aluminium definitely glows before it melts.

Sorry for the noise, this had to be investigated

Hmmm.  My statement was based on seeing (many times) molten aluminum being poured and not seeing it glowing.  I'd never tried heating foil with current.  I've no idea why there would be a difference, that looks almost white hot.

Edit:  I was unable to replicate your result with standard kitchen aluminum foil, it would repeatedly fuse before glowing.  Any specifics on how you did that?  Current, foil source, size, etc? 

[magic]

Narrow (maybe 1mm or so) strip of kitchen foil mounted to a transformer soldering iron. I guess the current has to be several amps because I tried shorting out a NiMH cell with a similar strip and it didn't glow.

Admittedly, my iron has built-in power adjustment (triac dimmer?) and I had to tweak it a little to get it to glow continuously without fusing. BTW, for this kind of stuff constant voltage is better than constant current, because metals typically have positive TCR so the former decreases power dissipation at high temperature while the latter increases it.

And it's not glowing white, that's just limited dynamic range of the camera. It really is orange to the naked eye.

Not sure what happens here, but if it melts, it stays in its original shape surprisingly well. At any rate, I think we can safely say that aluminium conductor glows before it fuses

[floobydust]

There are many research papers on aluminum bonding wires. Would be good to know how thick the wire is EVVO used. I also note the ends (toes) are huge and I wondered if they are touching any features?
neat failure analysis: https://www.semlab.com/examples/deviceexamples/
They call it "EOS electrical overstress" when fusing happens mid-span due to heatsinking at the ends. But we know... there was no overstress aside from forum members fusing 

Interesting is a tiny amount of silicon is added to the aluminum, then a double annealing process. IF this is done wrong, you get cracking in the wire - which might be something here, that the bonding wire itself failed due to cracking.
Personal experience with chinese metallurgy is they have no quality control, the country is quite used to things failing and their solution is to simply replace the product when you point out the annealing or heat treating is no good. No biggie 

Graph from Heraeus Electronics bonding wire

[Analog Kid]

Wouldn't it be cheaper (and better!) in the long run just to use copper for bond wires?
I mean, how expen$ive could that be? Even on a run of 100,000 pieces, the cost of the wire has got to be totally marginal.
Especially if you factor in the cost of all those other treatments, the silicon additive and the annealing.

[wraper]

Wouldn't it be cheaper (and better!) in the long run just to use copper for bond wires?
I mean, how expen$ive could that be? Even on a run of 100,000 pieces, the cost of the wire has got to be totally marginal.
Especially if you factor in the cost of all those other treatments, the silicon additive and the annealing.

You forget it's not all that simple. You cannot just ultrasonic bond anything to anything and expect it to be reliable. Not to say it seems copper bond wire is a recent thing, like 15 years of real mass production. Nobody will update old designs with that. Also material as such is not even an issue here. It's inadequately thin wire, and running only one when they could run two thicker wires at barely any additional cost. Another problem with using single wires is that BJT is likely not evenly loaded because current needs to run over the die from the opposite side.

[floobydust]

The boss needs to buy a Lamborghini. Think of all the profits EVVO reaps using cheapola bonding wire raking in the millipennies /s
Someone reviewed the bonding wire spec enough to use super thin for the ADJ pin, so they screwed up for that one high current wire. Oh and no testing done either.
Noopy die shot of 317H 0.5A TO-39 here's how it's done it's got the beef lol.

But seriously, I have never seen BoM costs for something like this IC.
I believe most of the costs are the die, but it seems to have been overshrunk really there is not enough room for bonding wires and where is that heat spreader anyway.

[wraper]

^Bond pad area is utilized by 50% at best. Also do not forget that 2x cross section would require just 1.4x increase in wire diameter. Not to say half of the bond pads were left unused. Regardless of the die quality, this problem has nothing to with the die but with inadequate packaging.

[floobydust]

The second failure is in testing, or lack thereof- that should have caught this packaging error.
They purport to have an ISO9001 quality system in place and clearly that failed as well, third failure.
I would have no confidence in the dies then, how are they for line/load regulation, noise, current-limit etc. ? LM337 would have the same problems.

[wraper]

IMHO they did nothing at all. Considering it's the same die/packaging as that fake LM338k I mentioned, just ordered the part from whoever sells this garbage with their brand name printed. I doubt it was an accidental error.