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| Laser-ing the IC markings off on a budget. |
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| Brumby:
--- Quote from: blueskull on March 24, 2021, 04:46:35 am ---OP: for that you nee a pulsed laser. --- End quote --- I wouldn't say "need" - but it is an option. --- Quote ---CW lasers might work, but you do induce a lot of thermal damage to the plastic, potentially degrading insulation resistance or even expose bonding wires. --- End quote --- The OP is well aware of this risk - it is the reason they started this thread! As stated earlier, I'd try out various settings on chips you don't care about. It shouldn't take long to dial in acceptable parameters. |
| beanflying:
Pulsed notionally higher powered fiber lasers or CO2 (pulsed or not) won't make much difference as the power needed to ablate the surface will be a constant. It is fairly common in Raster CO2 Laser engraving to play with the timing/switching of the pulse to get an effect or just a simple reduction in power and a change to the scan lines per X unit will drop the power and overlap of the beam. Just checked the scan lines on the sample runs I did were 0.05mm with a typical kerf of 0.16-17 (power is not uniform across the beam either) so there is a reasonable overlap that for speeds sake alone you would cut back as well as dropping the power put into the encapsulation. |
| Simon:
--- Quote from: mnementh on March 24, 2021, 03:45:47 am --- You know, like some devices I've seen that "accidentally" have a positive DC rail on a black wire, just for grins. ;) https://youtu.be/CSvf6FsSnjg --- End quote --- You mean like the entire German automotive standard wire colour coding? Black is positive, Brown is Negative - just for kicks, luckily wost stuff is reverse polarity protected. |
| coppercone2:
How I love this thread Hopefully your bosses pay off some cancer bills for those poor kids working on the unrepairable trash https://www.smithsonianmag.com/science-nature/burning-truth-behind-e-waste-dump-africa-180957597/ The threshold for china reverse engineering your stuff is probobly like 200 units |
| Simon:
I think if you truly want potting to be a method you need to go down the routes that whoever makes banking equipment use which of course will not be cheap. Obviously people like that will be using all the other means like locking software and encryption etc. |
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