LM723 die pictures

[Dan123456]

He said he wasn’t sure if it had to be fuming nitric or if it could just be good old “regular” 68% concentrated nitric?

I would love to give this a go as your results look so cool but don’t stock any RFNA / WFNA and don’t really like making it (68% is more than good enough for my uses! )

If you don't feel like reading the whole thread linked by Noopy, and I'm not even 100% sure if I ever described it in detail:

Pour 1~2ml into a 5ml beaker, drop the chip, cover with watch glass or at least HDPE bottle cap (for vapor reflux, reduces fuming and loss of acid).
Boil gently for a few minutes. Nitric acid remains transparent, allowing you to watch progress, only turns green from dissolved copper.

68% will eat exposed aluminium bonding pads, but won't reach under the passivation glass in short time. FNA passivates aluminium, hence the preference.

edit: Hopefully you know it already, but NO₂ is poison and stinks ugly like chlorine, so don't be an idiot, do it outside

Awesome! Thanks so much to both you and Noopy 

I’ve been reading through all the info and am super keen to give this a go! Thank you 

I would probably go down the chemical route as am more confident in my chemistry skills than I am with my electronics ones at this point think  To be completely honest, I think I would probably be far more likely to kill myself wiring up a furnace than I would working with most chemicals with a LD50 higher than cyanide

I am already thinking of maybe experimenting with a few different acids or solutions such as maybe testing out if H3PO4 works (might be an easy-to-find replacement for people in countries that don’t have access to HNO3 / H2SO4?) 

Agree! NO2 is some pretty nasty stuff! I have caught a lung full from being stupid once or twice and straight up thought I was dying 

That said, Noopy mentioned HF in the other thread… now that stuff… that stuff proper terrifies me!!! 

[Noopy]

People have tried a lot but unfortunately it seems that just sulfuric and nitric acid do the job.
Nevertheless feel free to find a new and more convenient way to open packages. I will buy you a beer and a lot of other people too. 

HF is really nasty. I just use it as Armour Etch (glass etching) since housewifes are allowed to use it. 

[Noopy]

The Motorola MC1723 was offered in different package variants. The index G stands for the TO package shown here. The additional index C is missing, which shows that the device is specified for the extended operating temperature range of -55°C to 125°C.






The die features the same circuit design as the MC1723C (https://www.richis-lab.de/LM723_14.htm).


https://www.richis-lab.de/LM723_18.htm

 

[iMo]

  I've been using the Motorola 1723 in DIP in my ADR1001#1 ref..

[Noopy]

I've been using the Motorola 1723 in DIP in my ADR1001#1 ref..

The 1723 as a substitute for the ADR1001? 

[iMo]

Yep, but do not tell anyone.. 

[Noopy]

some pics of the infinion SG3532 would be good to compair.

I have uploaded a SG3532!
I have put it in the voltage regulator thread:

https://www.eevblog.com/forum/projects/voltage-regulators-die-pictures/msg5265990/#msg5265990

https://www.richis-lab.de/voltageregulator23.htm

 

[Noopy]

We already had the CA723CT built by Harris Semiconductor (https://www.richis-lab.de/LM723_13.htm). Here we have the CA723T. The suffix T indicates the metal package. The suffix C has slightly poorer specifications. The bin we have here offers better characteristics and in addition is specified for an extended operating temperature range.








The CA723T contains the same design as the CA723CT. There are no differences visible on the die. It is most likely just a binning.


https://www.richis-lab.de/LM723_19.htm