Help decapping IC and taking photo of die - Page 1
Forum section: electronics / repair

author: giosif
author_rank: Frequent Contributor
timestamp: March 19, 2020, 08:44:50 pm
content: Hi,I have a dead custom IC (PLCC package) for which I'm trying to identify the original manufacturer.One option that came to mind in this direction is to decap the IC and try to read any initials which might be present on the silicon die.However, I've never done IC decapping and am worried I might break the die in the process.Is anyone here (ideally, UK based) who has the experience and the tools (and the will) to perform this task and take a photo of the silicon die under the microscope?Thank you!

author: shakalnokturn
author_rank: Super Contributor
timestamp: March 20, 2020, 01:10:05 am
content: Gossen Metra/LEM/Camille Bauer/Megger DMM?I'm sure enough Gossen designed their own ASICs, not certain if they manufactured themselves.Considering country of origin the most likely manufacturers would be Siemens or ITT (had become Micronas by then).Other than that no clue for decapping.Edit:As a side note: Siemens were a large shareholder of GMC-I in the 1960's.

author: poot36
author_rank: Frequent Contributor
timestamp: March 20, 2020, 02:47:37 am
content: This may help you or it may not:If you have a hot air gun you can try it your self.

author: magic
author_rank: Super Contributor
timestamp: March 20, 2020, 10:15:30 am
content: Definitely start with removing the stickerWhy do you need to know the manufacturer and are you absolutely sure it's dead?Quote from: poot36 on March 20, 2020, 02:47:37 amInteresting, it looks surprisingly effective considering the simplicity. By heating to even higher temperature (400~600°C) for a few minutes it's possible to permanently destroy epoxy so that it falls apart like charcoal.Beware that they lost one die and another one in the followup video about fake clock chips.

author: daqq
author_rank: Super Contributor
timestamp: March 20, 2020, 10:23:32 am
content: Laser engravers can be abused to decap ICs. Not a nice technique, but apparently works:

author: Noopy
author_rank: Super Contributor
timestamp: March 20, 2020, 10:25:13 am
content: I do it like this:https://www.eevblog.com/forum/projects/decapping-and-chip-documentation-howto/msg2663778/With my new "ofen" that works very well...I could open the package and take some pictures for you.Here you can see what I´m able to do:https://www.richis-lab.de/index.htmBUT:- You have to ship to germany.- There is no guarantee for success. Right now >90% of the decapped dies are ok but sometimes the "process" fails.If you find someone doing it chemically and having some experience with it the success probability is higher.How wide is the package? I get best results with my "ofen" but the opening is a little small. If the chip to wide I would trim it a bit. Should be no problem.

author: MadTux
author_rank: Frequent Contributor
timestamp: March 20, 2020, 12:22:00 pm
content: I usually do it by boiling the chip in 98% sulfuric acid, outside of course, because of the nasty SO2 fumes it makes.Usually have quite good success with it, but my microscopy equipment is rather bad, some ancient microscope from 1900 or so is all I have.But if it's really important, I can do decapping and send the die to someone with good microscope.