Microscope for decapped ICs - Page 1
Forum section: electronics / general

author: caius
author_rank: Regular Contributor
timestamp: July 15, 2015, 02:13:26 pm
content: Hi all, I have some decapped ICs and the chance to do more (actually I don't used nitric acid but a "burning" method) but I'm not able to take magnified HI-RES pictures.I'm not into microscope market so I was wondering if there are some not expensive models suitable for my purpose.Thanks in advance.

author: amyk
author_rank: Super Contributor
timestamp: July 16, 2015, 02:14:46 pm
content: It depends what type of ICs and how much detail you want. Individual transistors of early (~10um) process are visible with a magnifying glass, whereas a light microscope won't be able to see much of anything on those made in a sub-micron process as the features are far smaller than the wavelength of light.

author: tggzzz
author_rank: Super Contributor
timestamp: July 16, 2015, 03:26:42 pm
content: For amusement, I posted some pictures of late 70s Burr-Brown thick film hybrids. Definitelynotsub-micron!https://entertaininghacks.wordpress.com/2015/07/07/images-of-late-70s-burr-brown-thick-film-hybrid-ics/

author: TerraHertz
author_rank: Super Contributor
timestamp: July 17, 2015, 02:43:36 am
content: Quote from: caius on July 15, 2015, 02:13:26 pmSimilar to my situation. I found the search term 'metalurgical microscope' is a help. It means microscopes intended for reflected light use, inspecting opaque surfaces.My Olympus BHM adventures here:http://everist.org/NobLog/20150510_Olympus_bhm.htmI still haven't got a camera adapted well to the microscope, but that's not an intrinsic problem, just me getting sidetracked as usual.

author: EEVblog
author_rank: Unknown
timestamp: July 17, 2015, 02:47:26 am
content: Quote from: TerraHertz on July 17, 2015, 02:43:36 amI have an Olympus BHM as well, just need some time to get it going. Unfortunately the light source was broken on it like yours. Thanks for that info on the LED upgrade, will read in detail.

author: TerraHertz
author_rank: Super Contributor
timestamp: July 17, 2015, 10:31:23 am
content: Quote from: EEVblog on July 17, 2015, 02:47:26 amFor my next microscope illuminator project, I've come up with a better way of constructing the optical concentrator. Two parts combined:* Ebay search term: LED reflector collimator eg item 371258089004 and many others.There are sizes to suit the 10W and 50W flat LEDs. You may find that alone will work well enough with the lens included. Beware that what you end up with is a nice focused image of the LED chips.I'll be using just the reflector part, to get better matching from the LED to the concentrator cavity, and allow homogenizing of the light.* I'm planning to use several large LEDs combined for colour control in this one. So still need the optical concentrator method. But I'll be trying making a solid former of the optical cavity shape first (probably of wood), then molding the body structure around it. Either in casting epoxy or wrapped and soldered copper sheet.Then gluing reflective foil to the inside of the cavities, same as before.That project is getting posted here as it progresses:http://everist.org/NobLog/20150628_LED_lighting_mk3.htmThe 10W colour LEDs arrived today.

author: RogerRowland
author_rank: Regular Contributor
timestamp: July 24, 2015, 02:00:36 pm
content: Is it an easy thing to do, decapping an IC?I'm just asking because I work at a company that manufactures SEMs (scanning electron microscopes) and I'm wondering about using some decapped IC images for testing some of our image stitching software (for large scale microscopy).So, how does one decap an IC without destroying the contents?

author: helius
author_rank: Super Contributor
timestamp: July 24, 2015, 02:23:42 pm
content: It depends on the type. Some large chips like CPUs have metal lids that can be ripped off. For epoxy (plastic) potted chips, they can be embrittled with liquid nitrogen and then crushed, hopefully leaving the die undamaged. Or heated until the epoxy decomposes and crushed...But to decap the chip while preserving the bond wires so it can operate, the best method is to mill a slot above the die and fill it with red fuming nitric acid.

author: RogerRowland
author_rank: Regular Contributor
timestamp: July 24, 2015, 02:30:16 pm
content: Quote from: helius on July 24, 2015, 02:23:42 pmAhh, so not a simple thing then. Maybe it's easier to dig the window out of an EPROM like the older PIC16C* micros I wonder? I'll have to see what I can do that might give me some mileage.

author: helius
author_rank: Super Contributor
timestamp: July 24, 2015, 02:49:02 pm
content: Were you wanting to image the electrical charge in the chip as it operates? I know a SEM can do that.Quartz-window chips are a ceramic sandwich, the trick there is to separate the ceramic layers without ripping the traces. It might be possible to dremel just above the legs to take off the top layer.

author: RogerRowland
author_rank: Regular Contributor
timestamp: July 24, 2015, 03:03:45 pm
content: No, not interested in keeping it alive. Too tricky to set that up in a vacuum. I don't want to complicate things but just get the detailed structures for image processing.I'll have a look for some sacrificial components this evening

author: edavid
author_rank: Super Contributor
timestamp: July 24, 2015, 03:26:17 pm
content: Quote from: RogerRowland on July 24, 2015, 03:03:45 pmTO-5 packages are really easy, just cut off the lid.CERDIPs are pretty easy too (don't have to be quartz lid).

author: codeboy2k
author_rank: Super Contributor
timestamp: July 25, 2015, 12:20:14 am
content: Quote from: tggzzz on July 16, 2015, 03:26:42 pmThose are awesome! thanks for scanning and posting.Most c00l3st ... the bondwire toroid

author: tggzzz
author_rank: Super Contributor
timestamp: July 25, 2015, 03:28:38 pm
content: Quote from: codeboy2k on July 25, 2015, 12:20:14 amYou're welcome. They are pretty, aren't they!