Electronics > Projects, Designs, and Technical Stuff
Is "integrated circuit burn-in" a thing?
IDEngineer:
--- Quote from: floobydust on April 25, 2019, 08:59:59 pm ---Best to be careful and use scientific method (change only one thing at a time) to troubleshoot your problem. Encountering hassles now is much better than when in production...
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Amen to that! Which is why I'm digging into it now, rather than later.
The bottom line for me, so far, is that the ST part demonstrates this burn-in behavior while the Bosch-Sensortec part does not. Literally everything else is the same, they were installed on the same group of panelized-then-separated PCB's, all other components are identical and from the same reels, stuffed and reflowed at the same time, etc. There just aren't that many variables to play with, especially since "the other part" doesn't demonstrate the behavior.
It's aggravating.
IDEngineer:
--- Quote from: jmelson on April 25, 2019, 10:24:19 pm ---My guess is the OP's contract assembler used ordinary reflow, heating EVERYTHING to 250 C for a minute or more.
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That's exactly correct. However, they are very good at what they do. In literally tens of thousands of units they've done for us over the past 3-4 years I've never had a reflow problem, and never seen a problem like this one. That's why I'm so focused on the part, because it's such an outlier and only ONE part is exhibiting weirdness while its second source does not.
amyk:
The "typ" values in datasheets are usually chosen to demonstrate the best performance in one of several areas (such as power consumption), but as long as the parameter is within limits it shouldn't matter.
I recommend also the "buy several and solder them yourself" test, if you could also get a sample from what your assembler was using then that's even better.
This part has breakout boards available and is popular enough to be "Arduino-ised", if there was such a weird problem with it we would've heard many many times from others already.
IDEngineer:
--- Quote from: amyk on April 26, 2019, 12:04:04 am ---This part has breakout boards available and is popular enough to be "Arduino-ised", if there was such a weird problem with it we would've heard many many times from others already.
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That's what I felt as well. Which is why one of my theories (noted earlier in this thread) is that the part doesn't "sit still" very well. My long term tests have been unusual in the sense that most people don't just power up a MEMS motion sensor and then let it sit motionless for dozens of hours. Also, so far (fingers crossed) the prototypes we've send into the field haven't reported this error... and they don't sit motionless either. I'm thinking of building some sort of motion table and letting a long term test run on that, to test this theory, but not sure I have the time to spare anytime soon.
EDIT: All of the protos in the field came from the same, single build as the ones I'm using on the bench. So again, no variables there. Just a different use case, mine can sit motionless for hours at a time while those are in constant motion when powered up. Hence my theory....
AndyC_772:
--- Quote from: jmelson on April 25, 2019, 10:24:19 pm ---Maybe, maybe not! Yes, what you say is possible. But, if you solder one pin at a time, for just a second or so, the BODY of the part never gets heated more than 10 C above ambient. When reflowing, the whole component is heated to 200C+ above ambient. Maybe this part is really sensitive to that internal temperature
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Every surface mount component you can buy is designed, tested and rated for reflow soldering.
These parts are tiny (~4x4mm) QFN packages; you're not going to quickly solder the pins one at a time by hand without heat conducting into the bulk of the package.
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