9 ms·

Myth-busting article about radiation hardened microchips for space applications

109 points by amartology 6y ago

myself248 6y ago
Some wrinkles in the article, it looks like it was well-translated from the original, but figure 7 is explained "on the right" twice; one instance should say "on the left", and figure 8 is missing entirely. I wonder if the FDSOI back-charge technique could be cycled to provide periods of immunity, then "dump" the stored charge (while holding the chip in reset), then become immune again.. Fascinating stuff! Mostly over my head! Literally! :)
- amartology 6y ago
  I'll fix it, thanks. The problem occurred because it was not translated, but more "rewritten", and this particular figure was changed. Regarding actual question, that wouldn't work unfortunately. "Dumping" isn't possible as effects are complex and nonlinear. Maximizing total dose hardness via back gate voltage would require complex voltage control. But there could be something, for example, if one tries to use accelerated high-temperature annealing.
garmaine 6y ago
There are many different radiation environments in space, which a quick skim of this article seems to ignore entirely. Low earth orbit isn’t that high-rad because of the earth’s magnetic field. Go outside outside it and you need some rad hardening for sure. Orbit in the van allen belts or go somewhere like Jupiter and you need extensive rad hardening for sure.
- vvanders 6y ago
  You might just want to read the section called "Different orbits and other applications of radhard ICs".
taneq 6y ago
> Just like anyone else, they normally write code filled with crutches to be ready for yesterday's deadline and want more powerful hardware to mask their sloppy job; some would’ve used Arduino if it was properly certified. The (very interesting) main thrust of the article aside, I see this kind of sentiment a lot and I don't really understand it. Arduino's just a common dev board, running a standard microcontroller, plus some hand-holding libraries (which you can dispense with if you want.) Is there any actual legitimate reason that they're not suitable for production use? Or is it really just "real-embedded-devs-don't-use-Arduino" ego flexing?
- leonidasv 6y ago
  I think the author is talking about a (certified) radiation-hardened Arduino board.
  - duskwuff 6y ago
    They are not. No such product exists.
    - sigstoat 6y ago
      that was they author's point. some engineers would use it, if it existed.
      - taneq 6y ago
        And my point was why (ie. what real quantifiable reason) shouldn't they?
        amartology 6y ago
        The first Radhard Atmega device arrived just five years ago, so maybe someone is in a process of certification now) But your question sounds a bit like "why there are no Ferrari semi trucks?" Just because they are intended for different things)
- 6y ago
tallanvor 6y ago
I don't understand the need to editorialize by changing the title. If you read the title posted here, you may get the impression that there's no need for radiation hardened chips can be used. It would be better to use the actual title "Common misconceptions about space-grade integrated circuits". To me the actual title more properly reflects a good summation of the article: "The ultimate answer to a question if COTS chips can be used in space is “Yes, but”. There are many opportunities, but also many constraints."
- amartology 6y ago
  Your point is very valid, in retrospect I think that I shouldn't have changed the title.
tuatoru 6y ago
> all the fuss with lead-free solder was partially caused by the fact that lead and some other materials used in IC fabrication contain impurities of heavy elements like uranium. This is complete news to me. Lead free solder was mandated by the European Union's "Regulation of Hazardous Substances" legislation, whch was drawn up by a bunch of ninnies with no understanding of biochemistry, nor mathematics, nor epidemiology. Electronic devices are more reliable with tin-lead solder rather than Aluminum based solders.
- philjohn 6y ago
  Um, isn't one of the benefits, especially for hobbyists, that you're not inhaling lead-laced fumes?
  - wongarsu 6y ago
    Not at the temperatures hobbyists are soldering at. It's more of a concern for industrial soldering. Hobbyists have to worry about the fumes from flux instead, and lead free solder requires more flux.
    - pasabagi 6y ago
      I don't really get this. Surely the problem is you're handling lead in a home context? That's never going to be safe, since unless you're very careful about cleanup, you're going to get lead in your food. To me, all this talk about lead being so much better feels a bit silly. As a craftsman, I can see that lead is nicer to work with, and makes for more pretty results. As a dad, I'm pretty glad that every electronic object isn't laced with lead - in fact, I'm glad about every measure full stop that reduces the industrial usage of lead. One of these things is way more important to me than the other.
      - formerly_proven 6y ago
        I don't understand what you're saying. Using hand soldering tools, the tin-lead alloy becomes a liquid, sure there might be traces of lead going into the air that you can detect (ppt? ppq?), but that doesn't make it a health hazard. You might abrade traces of lead onto your hands handling soldering wire, but surely washing your hands after soldering gets rid of that. If you do a few mistakes you might get small lead balls in your work area, but even then I don't see how it gets in my food. I don't understand why solid lead or alloyed lead is supposed to be a safety problem by itself. It's not radioactive, you don't get sick by standing next to it, you have to abrade it and eat the shavings. Heating soldering wire isn't creating lead vapors like leaded gasoline does.
formerly_proven 6y ago
Fun fact, the still persistent use of "rad" instead of Gray (RoW) unit seems to stem from the US NIST confusing radians with rads and saying rad is an SI-conformant unit (which it never was).
cultureswitch 6y ago
The knowledge required to understand the vocabulary used in this article seems to disqualify anyone who might have such misconceptions to actually read it to the end.
- amartology 6y ago
  Oh, I've seen examples of these from the people who managed to work in space industry for decades. Also, I hoped that I gave enough terms and definitions in the beginning( I would appreciate any feedback on what could make the text better and more understandable for wider audience.
geomark 6y ago
This is a good article. It covers all the facets of radiation hardening pretty well. I worked on a radiation hardened processor chipset that had to be very rad hard - total dose, prompt dose, SEU all had to be addressed. That required measures be taken at the process, physical layout and architecture levels while making it performant and low power. Conclusion: very difficult, but possible, and some very interesting problems to solve (like how to mitigate the effects of an SEU in the instruction register at the moment of execution). I also was peripherally involved with testing COTS memory chips for radiation hardness. They only had a modest total dose requirement. That was messy for the reasons mentioned in the article, like the fact that the manufacturers are always tweaking process and design parameters to optimize for the commercial DRAM market. So from one lot to the next the radiation hardness was unpredictable. Conclusion: costly, time consuming and not sustainable.
thrwway34 6y ago
Bear in mind that it's a Russian site and they have a huge problem with producing or buying radiation-hardened chips. So it's kinda 'sour grapes' attitude.
- amartology 6y ago
  It's not "huge" problems. Russian state of art radhard design is mostly on par with what exists in Europe and just a couple of generations behind the USA. Most of production is obviously abroad, and nobody actually cares, as it involves much less money than Huawei case) Also, this site was chosen for publishing because it was easy and because they actually give you some audience. Getting the same attention at Medium would be much harder, and a copy of this text, which I posted at LinkedIn, got something like 60 views. LinkedIn has a great publication editor, by the way. If you have an advice on some better place where I could publish scipop texts about microchips, that would be really appreciated.
  - thrwway34 6y ago
    If they really were 'on par' then you won't have issues with your satellites.
    - amartology 6y ago
      This "you" doesn't apply to me as I don't live in Russia. The problems with satellites are mostly due to competely different factors, not the state of radhard IC design. For example, transition from imported to domestic EEE components is painful, as the demand is much higher than industry's capacity.
      - forgondolin 6y ago
        If I remember right. The north americans made a lot of noise when SpaceX managed to take Nasa people to space, because USA was relying on Russian space program, lol. So I think they are on par

109 points by amartology 6y ago

Some wrinkles in the article, it looks like it was well-translated from the original, but figure 7 is explained "on the right" twice; one instance should say "on the left", and figure 8 is missing entirely. I wonder if the FDSOI back-charge technique could be cycled to provide periods of immunity, then "dump" the stored charge (while holding the chip in reset), then become immune again.. Fascinating stuff! Mostly over my head! Literally! :)

amartology 6y ago
I'll fix it, thanks. The problem occurred because it was not translated, but more "rewritten", and this particular figure was changed. Regarding actual question, that wouldn't work unfortunately. "Dumping" isn't possible as effects are complex and nonlinear. Maximizing total dose hardness via back gate voltage would require complex voltage control. But there could be something, for example, if one tries to use accelerated high-temperature annealing.

garmaine 6y ago

There are many different radiation environments in space, which a quick skim of this article seems to ignore entirely. Low earth orbit isn’t that high-rad because of the earth’s magnetic field. Go outside outside it and you need some rad hardening for sure. Orbit in the van allen belts or go somewhere like Jupiter and you need extensive rad hardening for sure.

vvanders 6y ago
You might just want to read the section called "Different orbits and other applications of radhard ICs".

taneq 6y ago

> Just like anyone else, they normally write code filled with crutches to be ready for yesterday's deadline and want more powerful hardware to mask their sloppy job; some would’ve used Arduino if it was properly certified. The (very interesting) main thrust of the article aside, I see this kind of sentiment a lot and I don't really understand it. Arduino's just a common dev board, running a standard microcontroller, plus some hand-holding libraries (which you can dispense with if you want.) Is there any actual legitimate reason that they're not suitable for production use? Or is it really just "real-embedded-devs-don't-use-Arduino" ego flexing?

leonidasv 6y ago
I think the author is talking about a (certified) radiation-hardened Arduino board.
- duskwuff 6y ago
  They are not. No such product exists.
  - sigstoat 6y ago
    that was they author's point. some engineers would use it, if it existed.
    - taneq 6y ago
      And my point was why (ie. what real quantifiable reason) shouldn't they?
      - amartology 6y ago
        The first Radhard Atmega device arrived just five years ago, so maybe someone is in a process of certification now) But your question sounds a bit like "why there are no Ferrari semi trucks?" Just because they are intended for different things)
6y ago

tallanvor 6y ago

I don't understand the need to editorialize by changing the title. If you read the title posted here, you may get the impression that there's no need for radiation hardened chips can be used. It would be better to use the actual title "Common misconceptions about space-grade integrated circuits". To me the actual title more properly reflects a good summation of the article: "The ultimate answer to a question if COTS chips can be used in space is “Yes, but”. There are many opportunities, but also many constraints."

amartology 6y ago
Your point is very valid, in retrospect I think that I shouldn't have changed the title.

tuatoru 6y ago

> all the fuss with lead-free solder was partially caused by the fact that lead and some other materials used in IC fabrication contain impurities of heavy elements like uranium. This is complete news to me. Lead free solder was mandated by the European Union's "Regulation of Hazardous Substances" legislation, whch was drawn up by a bunch of ninnies with no understanding of biochemistry, nor mathematics, nor epidemiology. Electronic devices are more reliable with tin-lead solder rather than Aluminum based solders.

philjohn 6y ago
Um, isn't one of the benefits, especially for hobbyists, that you're not inhaling lead-laced fumes?
- wongarsu 6y ago
  Not at the temperatures hobbyists are soldering at. It's more of a concern for industrial soldering. Hobbyists have to worry about the fumes from flux instead, and lead free solder requires more flux.
  - pasabagi 6y ago
    I don't really get this. Surely the problem is you're handling lead in a home context? That's never going to be safe, since unless you're very careful about cleanup, you're going to get lead in your food. To me, all this talk about lead being so much better feels a bit silly. As a craftsman, I can see that lead is nicer to work with, and makes for more pretty results. As a dad, I'm pretty glad that every electronic object isn't laced with lead - in fact, I'm glad about every measure full stop that reduces the industrial usage of lead. One of these things is way more important to me than the other.
    - formerly_proven 6y ago
      I don't understand what you're saying. Using hand soldering tools, the tin-lead alloy becomes a liquid, sure there might be traces of lead going into the air that you can detect (ppt? ppq?), but that doesn't make it a health hazard. You might abrade traces of lead onto your hands handling soldering wire, but surely washing your hands after soldering gets rid of that. If you do a few mistakes you might get small lead balls in your work area, but even then I don't see how it gets in my food. I don't understand why solid lead or alloyed lead is supposed to be a safety problem by itself. It's not radioactive, you don't get sick by standing next to it, you have to abrade it and eat the shavings. Heating soldering wire isn't creating lead vapors like leaded gasoline does.

formerly_proven 6y ago

Fun fact, the still persistent use of "rad" instead of Gray (RoW) unit seems to stem from the US NIST confusing radians with rads and saying rad is an SI-conformant unit (which it never was).

cultureswitch 6y ago

The knowledge required to understand the vocabulary used in this article seems to disqualify anyone who might have such misconceptions to actually read it to the end.

amartology 6y ago
Oh, I've seen examples of these from the people who managed to work in space industry for decades. Also, I hoped that I gave enough terms and definitions in the beginning( I would appreciate any feedback on what could make the text better and more understandable for wider audience.

geomark 6y ago

This is a good article. It covers all the facets of radiation hardening pretty well. I worked on a radiation hardened processor chipset that had to be very rad hard - total dose, prompt dose, SEU all had to be addressed. That required measures be taken at the process, physical layout and architecture levels while making it performant and low power. Conclusion: very difficult, but possible, and some very interesting problems to solve (like how to mitigate the effects of an SEU in the instruction register at the moment of execution). I also was peripherally involved with testing COTS memory chips for radiation hardness. They only had a modest total dose requirement. That was messy for the reasons mentioned in the article, like the fact that the manufacturers are always tweaking process and design parameters to optimize for the commercial DRAM market. So from one lot to the next the radiation hardness was unpredictable. Conclusion: costly, time consuming and not sustainable.

thrwway34 6y ago

Bear in mind that it's a Russian site and they have a huge problem with producing or buying radiation-hardened chips. So it's kinda 'sour grapes' attitude.

amartology 6y ago
It's not "huge" problems. Russian state of art radhard design is mostly on par with what exists in Europe and just a couple of generations behind the USA. Most of production is obviously abroad, and nobody actually cares, as it involves much less money than Huawei case) Also, this site was chosen for publishing because it was easy and because they actually give you some audience. Getting the same attention at Medium would be much harder, and a copy of this text, which I posted at LinkedIn, got something like 60 views. LinkedIn has a great publication editor, by the way. If you have an advice on some better place where I could publish scipop texts about microchips, that would be really appreciated.
- thrwway34 6y ago
  If they really were 'on par' then you won't have issues with your satellites.
  - amartology 6y ago
    This "you" doesn't apply to me as I don't live in Russia. The problems with satellites are mostly due to competely different factors, not the state of radhard IC design. For example, transition from imported to domestic EEE components is painful, as the demand is much higher than industry's capacity.
    - forgondolin 6y ago
      If I remember right. The north americans made a lot of noise when SpaceX managed to take Nasa people to space, because USA was relying on Russian space program, lol. So I think they are on par