high temperature influence IC

Hey Guys,

I'm studying forensic science and i'm going to do a project about the influence of high temperatures on IC and the data on it.


Electronics is not realy my cup of tea but i'll do my best.

The IC that i'm going to use is a M24C16 - WBN6P EEPROM DIP8.

I want to know what the max temp specifications are for the IC.
I have the datasheet and i see some temperatures in it.

But do i have to look to the Ambient operating temperature or the Storage temperature? Or is it something else?

grtz

M24Cxx-Wxx6 max operating temp is listed as 85C and storage temp is 150C so you may want to do two experiments, the first with power applied and outputting a constant stream of data (a 10101010 stored in even bytes, 01010101 in odd bytes), and step the temp to 90C and see if the data gets corrupted. the second experiment would be to store a pattern in memory, and with the chip powered off, cycle the temp to 150C, then back to normal and read the pattern to see if it has changed, then continue the cycling, raising the test temp a few degrees each time.

I've programmed microcontrollers that contain EEPROM, and then reflow soldered them at 230 deg C, and the programme remains. Those would have been SO8 packages which are much smaller than DIL 8, so I am fairly sure that the whole IC gets to 220 deg C or so, and still retains the memory.

I would guess that the data would not be retained for very long at those temperatures.

Thanks unclejed!

What i'm going to do is to simulate fire temperatures. So i'll have to heat up the IC's to max 1000 degrees celsius.

this is the content of the research:
Programming memories with a known pattern, followed by exposing these memories to increasing temperatures for various periods, describing and analyzing the implications for the reliability of data, loss of these data and the changes that occur in memory itself. For the analysis various methods are used. The assignment can be continued by describing of the effects of the analyse methods. Ultimately, the test should be completed with a recommended method for preservation and examination of burnt electronics.




I think i'll make a temp/time range and test the IC's first at: 200°C/10sec, 400°C/10 sec, 600°/10sec etc......................... 200°C/5min, 400°C/5min etc........................
200°C/30min, 400°C/30min 600°C/30min etc........



then i'll check the IC's for data loss or data change. or if the chip is unusable for data recovery.

Literature tells me that at a temperature of 450°C data is retained in the memory of EEPROM . In some cases the data is retrievable by rewiring the chip.

just remember that any solder or sockets the chip is connected to will melt. also you may want to look up the doping temperatures of silicon to see where the internal junctions break down from dopant migration. there are many ways a chip can fail, and with high temperatures, this failure mode is very likely.

So i'll have to heat up the IC's to max 1000 degrees celsius

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In that case I think data loss will be the least of your worries. At that temp you'll probably have complete IC loss , especially if the IC is a plastic-bodied type.

alec_t said:

In that case I think data loss will be the least of your worries. At that temp you'll probably have complete IC loss , especially if the IC is a plastic-bodied type.

Click to expand...

Yeah, I think this will happen, but I have access to all kinds of equipment to "fix" broken IC's. I run an internship at a forensic lab at the digital department.

So I'll look for the temp/time where the chip fails and look what causes that fail. The plastic package melting is not the problem. I can still get the IC out of the package with all kinds of techniques and use a wedge bonder to rewire the IC.

Wow. That kit sounds impressive....and horribly expensive

Yeah it is even possible for me to open the package with laser and I think they got equipment from Kulicke & Soffa to rewire IC's. pretty expensive things. I still dont know how all this works but i have 20 weeks left to find out.