Video Repair of an Agilent E3620A Plus IC Decapping Tutorial - Page 1
Forum section: electronics / testgear

author: Hugoneus
author_rank: Frequent Contributor
timestamp: April 26, 2015, 05:23:00 pm
content: Enjoy!Watch the video here: [41 Minutes]http://youtu.be/HembEL6PbE4More videos at The Signal Path:http://www.TheSignalPath.com

author: radhaz
author_rank: Regular Contributor
timestamp: April 26, 2015, 07:11:07 pm
content: Great video!

author: Vgkid
author_rank: Super Contributor
timestamp: April 26, 2015, 07:19:49 pm
content: Thanks for the video, the joys of chemistry. At least nothing blew up.

author: HighVoltage
author_rank: Super Contributor
timestamp: April 26, 2015, 09:20:07 pm
content: Another great repair video from you.Thanks so much

author: Hugoneus
author_rank: Frequent Contributor
timestamp: April 26, 2015, 10:30:43 pm
content: You are welcome!

author: dadler
author_rank: Unknown
timestamp: April 26, 2015, 11:48:31 pm
content: Only on your channel do we find the unique combination of:the cleanest and most organized home electronics lab I have ever seennitric acida michelson interferometerthe insides of scopes that cost as much as a housefrequent use of the word 'terahertz'at least two of every class of test equipment one could dream ofattempted repairs that almost always turn into successful repairsfrequent use of various alcohols for both cleaning and imbibinga guy who just happens to work in the building where the transistor was inventedNeedless to say, love the channel! Thanks for another great video--very cool to see the magnified dies that you were able to reveal at home with careful chemistry.

author: MadTux
author_rank: Frequent Contributor
timestamp: April 27, 2015, 01:47:55 am
content: Great video, nice to see that the HP E3620E works again.That decapping method you use is inefficient, however.If you go fully destructive, ie fully dissolved package, you better use hot/boiling sulphuric acid in a test tube, since it's much easier to get and has no nasty NOx production. Furthermore aqueous nitric acid is far more corrosive to metals => much more damage to the metal layers of the die.The trick with nitric acid is that you can remove the package specifically, with no attack to metal traces, since pure nitric acid has no water in it that removes the oxides/nitrates which protect the metal. To get the anhydrous nitric acid, you need an glass destilation setup, where you can remove the water from commercial 53-65% nitric by using 98% sulphuric acid as dehydration agent or use sulphuric acid to liberate pure nitric acid from alkali metal nitrates (NaNO3, KNO3).Works really great, did that several years ago and as I was quite pyromanic back then, I had plenty of anhydrous nitric acid available. Best method to decap the chip is to put it onto hotplate (into fumehood/outside, with gloves and faceshield, since it splashes quite strongly), heat in near/to the boiling point of nitric acid and use a pipette to put single drops of nitric acid onto the center of the chip, where the die sits.The nitric acid will vigorously attack the package and start to boil. This removes any reaction products that might attack the bonding wires or lead traces in the package. When finished, clean with ethanol and put in ultrasonic bath with acetone for a while.If you stop at the right time, you can get quite nice chips with bond wires fully intact, that even work that way. Difficult part is to know when to stop, since black goo from the package obscures the die in the process and you have to guess when to stop. Too long and the die gets fully exposed and detaches from the package.

author: Hugoneus
author_rank: Frequent Contributor
timestamp: April 27, 2015, 01:54:57 am
content: Quote from: MadTux on April 27, 2015, 01:47:55 amThanks for your suggestions. By the way, the die is not in danger from the acid. Only the pads have exposed metal and are often made from Al.

author: MadTux
author_rank: Frequent Contributor
timestamp: April 27, 2015, 02:25:08 am
content: Quote from: Hugoneus on April 27, 2015, 01:54:57 amI know, there's a SiO2 passivation layer on top of the die.But in my experience it doesn't completely stop the acid from attacking the chip, especially on small feature sizes and if you don't know how long to wait until the chip is completely dissolved. So I expected far more damage by using aqueous nitric acid, than actually happened (hadn't watched the complete video when posting)

author: Hugoneus
author_rank: Frequent Contributor
timestamp: April 27, 2015, 01:56:25 pm
content: @dadlerI should have somehow used liquid nitrogen too!

author: ion
author_rank: Regular Contributor
timestamp: April 27, 2015, 05:48:47 pm
content: Another great video!What temperature did you heat the nitric acid to? I had a go at decapping a while back but the cold acid didn't do anything. I was planning on trying it on a hotplate and it would be nice to have a starting point.

author: BFX
author_rank: Frequent Contributor
timestamp: April 27, 2015, 06:49:46 pm
content: Finally video when you need to use longer time than one hour your soldering ironBut first part of video is ... so lucky man(standard)But at all, youur videos is the best one

author: mtdoc
author_rank: Super Contributor
timestamp: April 27, 2015, 07:01:28 pm
content: Quote from: Hugoneus on April 27, 2015, 01:56:25 pmGreat video!How hard is it to get nitric acid outside of a professional setting? I haven't had access to any since my basic science research days. Obviously dangerous stuff if proper precautions are not taken.I do have easy access to lots of liquid nitrogen. What kind of use is it for an electronic hobbyist?

author: macboy
author_rank: Super Contributor
timestamp: April 28, 2015, 02:17:09 pm
content: Quote from: Hugoneus on April 26, 2015, 05:23:00 pmI enjoyed watching your repair of the water damaged E3620A. I have a few of those supplies myself and I really like them. They are low noise and stable.They are hard to find, but you can eventually locate two service notes for the E3620A on Keysight's website. One of them covers the issue of broken grey key caps. If your supply falls within a specified serial number range, they will replace them free of charge. The service note says "Agilent responsible: Always" meaning there is no expiry on their liability for replacing those broken key caps. They sent me several sets for my supplies a few years ago.List of service notes for E3620AService note E3620A-07 concerning cracked grey key caps