Fuming nitric acid will eat through most epoxy and chip casings. Of course you won't see any ID numbers since you'll be looking at the chip die core.
Your better bet is to look at the surrounding chips - find for example the USB interface chip - then look for how they hook to the epoxy blob, look at the data sheets for the usb chip to find the pin assignments - then see if you can guess what kind protocol it uses (I'm guessing i2c or SPI). -m On Tue, Apr 20, 2010 at 08:50:17AM -0400, Jack Chastain wrote: > Fred's right - this stuff is similar to epoxy glue - it won't melt with > anything you can easily do at home. > > If you are really, really interested in getting under it though, my son, > currently in Dahlgren VA, is a Micro Miniature repair tech in t\he Navy - > and he "has ways" normal humans don't have. I could ask him if he thinks he > could get the potting off, but I sincerely doubt you would be able to read > any meaningful chip information after. > > I used to do this kind of thing myself hundreds of years ago - more from > curiosity than anything else. I woudl not anticipate things to actually work > after, if you know what I mean. > > JC > > On Tue, Apr 20, 2010 at 7:47 AM, <[email protected]> wrote: > > > > > Is it shaped like a dome over the printed circuit board? If so, it's a > > "chip-on-board" assembly, where the silicon die is wired directly to the > > PCB. See http://www.siliconfareast.com/cob.htm. > > > > If that' is the case, the "black glop" - the encapsulation resin - isn't so > > much to hide the chip as to protect it. And since it's a resin, it's not > > going to melt with a heat gun. Removal is sometimes performed in labs for > > test or for reverse engineering purposes. Last time I saw a resin removal, > > it involved warm fluorhydric acid, not something you'd want to try at home. > > > > -- Fred > > > > On Tuesday 20 April 2010 00:17:03 Clyde Cottingham - > > [email protected] wrote: > > > I'm not an expert, but I would try heat - a heat gun. > > > ----- Original Message ----- > > > From: Adam > > > To: [email protected] > > > Sent: Monday, April 19, 2010 10:47 PM > > > Subject: [mhvlug] Hidden Chips > > > > > > > > > What's that cheap black glop that hardens that they put over chips > > > when they don't want anyone to be able to see the numbers on it? More > > > important, how can I remove it and read whatever numbers are on the > > > chip? The board and chip don't need to be functional, and time isn't > > > much of a concern. Thanks in advance for any suggestions! > > > > > > BTW, the camera it's from was part of Linux's libgphoto2 project, > > > helping implement support for the JL2005B/C/D chips, often found in > > > "toy" digital cameras (USB ID 0x0979:0x0227). > > > > > > Adam > > > > > > _______________________________________________ > > > Mid-Hudson Valley Linux Users Group http://mhvlug.org > > > http://mhvlug.org/cgi-bin/mailman/listinfo/mhvlug > > > > > > Upcoming Meetings (6pm - 8pm) MHVLS Auditorium > > > May 5 - Crack and LLVM > > > Jun 2 - Android > > > Jul 7 - July 2010 Meeting > > > > > > > > _______________________________________________ > > Mid-Hudson Valley Linux Users Group http://mhvlug.org > > http://mhvlug.org/cgi-bin/mailman/listinfo/mhvlug > > > > Upcoming Meetings (6pm - 8pm) MHVLS Auditorium > > May 5 - Crack and LLVM > > Jun 2 - Android > > Jul 7 - July 2010 Meeting > > > > > > -- > Eschew obfuscation and pompous prolixity. > > Light a man a fire, he is warm for the night. > Light a man afire, he is warm for the rest of his life. > _______________________________________________ > Mid-Hudson Valley Linux Users Group http://mhvlug.org > http://mhvlug.org/cgi-bin/mailman/listinfo/mhvlug > > Upcoming Meetings (6pm - 8pm) MHVLS Auditorium > May 5 - Crack and LLVM > Jun 2 - Android > Jul 7 - July 2010 Meeting -- Mike Kershaw/Dragorn <[email protected]> GPG Fingerprint: 3546 89DF 3C9D ED80 3381 A661 D7B2 8822 738B BDB1 If you can keep your head, while all others around you are loosing theirs, then you must be the one holding the axe. -- Anonymous
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_______________________________________________ Mid-Hudson Valley Linux Users Group http://mhvlug.org http://mhvlug.org/cgi-bin/mailman/listinfo/mhvlug Upcoming Meetings (6pm - 8pm) MHVLS Auditorium May 5 - Crack and LLVM Jun 2 - Android Jul 7 - July 2010 Meeting
