
Myth-busting article about radiation hardened microchips for space applications - amartology
https://habr.com/en/post/518366/
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tallanvor
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
Your point is very valid, in retrospect I think that I shouldn't have changed
the title.

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taneq
> 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?

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turbinerneiter
I don't understand it either.

The main part of Arduino is the hardware abstraction library. Especially for
the standard stuff, like iwc, spi, ... this hal makes your code portable
between different microcontrollers!

The alternative to Arduino hal is to use the vendor libraries. By doing that,
you lock yourself in to the specific controller you are using right now. Also,
the quality of the official sdks often enough is joke.

The next thing is the library ecosystem. A device driver library, i.e. to use
a certain sensor, from the Arduino evosystem will work on every
microcontroller with Arduino support, which is a very very long list.

The arguments against Arduino?

It's not _professional_.

Yeah, try the vendor library, sdk and ide and tell me that's better ...

You are relying on code that _somr guy in the internet_ wrote.

Jup. That's how the whole industry works. If your are using windows, you are
using code some guy at the internet wrote. Did you ever get recourse from MS
after you got a BSOD? Relying on code from other people is how we are able to
get anything done. If you wrote everything from scratch, you couldn't ever
ship anything. And hey, you got that code from that guy on the internet for
free. So do the world and yourself a favour, review the code and upstream any
improvements you find!

The IDE sucks.

So does the vendor IDE and nobody is using that stuff anyway. Use
platformio.org

There is many situations where Arduino is a valid option.

~~~
jack_h
Honestly I think in the embedded world HALs are a problem with how diverse the
micro controller area is getting - especially heterogeneous multi-core chips.
HALs end up targeting the least common denominator but there may be a really
good reason why you would want a particular micro controller in the first
place.

I think Andrei Alexandrescu has a good idea that he presented in his talk
about compile time introspection^[1]. That combined with something like ARMs
SVD, but vastly expanded to include practically all hardware resources, might
be the future. That way you could use exactly what you need.

Of course the embedded world changes very slowly, so if this every does happen
I'll be long retired...

^[1]
[https://www.youtube.com/watch?v=tcyb1lpEHm0](https://www.youtube.com/watch?v=tcyb1lpEHm0)

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geomark
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.

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myself248
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
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.

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formerly_proven
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).

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thrwway34
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
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
If they really were 'on par' then you won't have issues with your satellites.

~~~
amartology
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
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

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cultureswitch
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
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.

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tuatoru
> 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
Um, isn't one of the benefits, especially for hobbyists, that you're not
inhaling lead-laced fumes?

~~~
wongarsu
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
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
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.

~~~
pasabagi
Lead is soft - you're definitely leaving traces of lead on your hands when you
handle it. That then goes onto your clothes, your skin, and everything you
touch.

But anyway - it's not really the point. The point is, I can confidently say
that some idiot burning a trash bin isn't going to scatter lead all over the
local enivroment - ditto a house fire, or a car crash, or somebody dumping a
computer in a stream.

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garmaine
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
You might just want to read the section called "Different orbits and other
applications of radhard ICs".

