Electronic components aging

On Tue, 15 Oct 2013 09:34:27 -0700 (PDT), edward.ming.lee@gmail.com =
wrote:

>
>> Would designers of those Jupiter/Staurn satellites, etc jump in here? =
Give =20
>> back to the community. Their stuff works ten years and upwords of 25 =20
>> years. Be great if they wrote a little history of the 'battles' one =
must =20
>> embark on and the design philosophy required to overcome THOSE =
reliability =20
>> obstacles.
>
>But they don't have the same enemies: Air and Water.  Space might be =
easier to deal with than mother Earth.

But Space has severe thermal management issues, it is a really good
insulator after all.  Also contact erosion is a major player in relay
life, the design has to control that or the system dies early.  I know i
did some testing of relays for space use.

?-)

josephkk wrote:

> On Tue, 15 Oct 2013 13:40:24 +0100, Paul E Bennett
> <Paul_E.Bennett@topmail.co.uk> wrote:
> 
>>Piotr Wyderski wrote:
>>
>>> Speaking of high reliability... I think that it is often
>>> a somewhat neglected issue, so I start this thread as a
>>> mean to collect *practical* observations for people who
>>> care about long MTBF. In other words, "if I had to build
>>> a device which should last 50 years, I would... what?"
>>
>>With the best will in the world, there is no electronics based technology
>>that will last that long. It is hard enough doing designs that are
>>required to have a life of 20 or 25 years with minimal (no) maintenance.
>>After that time the equipment is replaced in major refurbishment
>>programmes.
>>
>>Any component that relies on the long term stabiliity of chemistry will
>>degrade and fail eventually.  Even in the mechanical world metals like
>>Iron and Stainless Steel will change over time.
>>
>>Only in software can you achieve really long lifetimes (if you are careful
>>about your design) but then what would you have left to run it on?
> 
> Try looking at some serious long term infrastructure systems.  There is
> plenty of SCADA that has already lasted as much as 60 years or more.  Lots
> more in heavy industries (refining, major metal mills, chemical plants,
> water treatment, wastewater treatment, etc.,) where replacement costs get
> really really big.
> 
> ?-)

I don't suppose that those systems are still running without having had some 
maintenance (board swaps, repairs etc). Would you wish to guarantee that any 
system you design today will still be operating that far in the future.

I don't know where your utilities are based but I am certain that the ones 
near me have all upgraded their systems over the years (just to cope with 
demands).

-- 
********************************************************************
Paul E. Bennett IEng MIET.....<email://Paul_E.Bennett@topmail.co.uk>
Forth based HIDECS Consultancy.............<http://www.hidecs.co.uk>
Mob: +44 (0)7811-639972
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********************************************************************

"miso" <miso@sushi.com> wrote in message 
news:l3nkt0$tdv$1@speranza.aioe.org...
> Mosfets have a threshold voltage shift related to how many times they 
> are switched. The rule of thumb is your chip should be able to last 10 
> years at the maximum clock frequency. But of course, this isn't hard and 
> fast or even written down.
>
> Basically a logic circuit will still work if the fet threshold voltage 
> changes over time. But if there is some critical timing and the fet 
> threshold voltage got larger, it will have less drive and thus the chip 
> becomes slower.
>
> The threshold shift effect has been around since the 1um days. I believe 
> it is related to hot carriers. All sorts of foo was created over the 
> years to keep this problem tolerable.

What's the mechanism of that, residual sodium (or etc.) ions???  Hot 
carriers don't just go loitering in pure silicon...

Tim

-- 
Seven Transistor Labs
Electrical Engineering Consultation
Website: http://seventransistorlabs.com 

Hi Joseph,

On 10/16/2013 11:46 PM, josephkk wrote:
> On Tue, 15 Oct 2013 13:40:24 +0100, Paul E Bennett
> <Paul_E.Bennett@topmail.co.uk> wrote:
>
>> Piotr Wyderski wrote:
>>
>>> Speaking of high reliability... I think that it is often
>>> a somewhat neglected issue, so I start this thread as a
>>> mean to collect *practical* observations for people who
>>> care about long MTBF. In other words, "if I had to build
>>> a device which should last 50 years, I would... what?"
>>
>> With the best will in the world, there is no electronics based technology
>> that will last that long. It is hard enough doing designs that are required
>> to have a life of 20 or 25 years with minimal (no) maintenance. After that
>> time the equipment is replaced in major refurbishment programmes.
>>
>> Any component that relies on the long term stabiliity of chemistry will
>> degrade and fail eventually.  Even in the mechanical world metals like Iron
>> and Stainless Steel will change over time.
>>
>> Only in software can you achieve really long lifetimes (if you are careful
>> about your design) but then what would you have left to run it on?
>
> Try looking at some serious long term infrastructure systems.  There is
> plenty of SCADA that has already lasted as much as 60 years or more.  Lots
> more in heavy industries (refining, major metal mills, chemical plants,
> water treatment, wastewater treatment, etc.,) where replacement costs get
> really really big.

Yes, but I suspect each of those systems are actively *maintained*.
I.e., *AS* parts of them fail, they are repaired and replaced.
This is very different than a "hands off" approach (e.g., deep
space probe that can't be "serviced" after its launch).

There are lots of things you can do to improve reliability,
probabilistically -- not sure how *deterministic* those efforts
would be, though!  E.g., entering an electronically controlled
"stasis pod" and HOPING you've done the engineering right!
(then, again, if you *didn't*, YOU sure will never know!  :> )

But, a lot of that is predicated on having some idea as to usage
patterns, extremes, etc.  E.g., how you select a battery/charger
for a cell phone is very different than for a power tool or a
UPS.

[As an aside, what gives with the pricing on NiMH AAA cells?  It
seems like ~$3/ea is the going rate.  Sheesh!  Cheaper to buy
a boatload of alkalines...]

Look, for example, at WE's designs for subscriber end devices (where
the sheer NUMBER and physical distribution made upgrades/replacements
virtually impossible!).  Contrast that with their (still robust!)
designs for CO equipment (costlier but far easier to replace than
the subscriber end)

I've had occasion to design high volume, long service life, high
repair/replace cost devices and it's REALLY a completely different
world!  Something like 10 years is relatively easy.  When you
start talking 30 or more years, you start actively gauging whether
or not you could, perhaps, be "gone" and NOT have to worry/know
if you've screwed up!  :>

Hi Paul,

On 10/17/2013 12:32 AM, Paul E Bennett wrote:
> josephkk wrote:
>
>> On Tue, 15 Oct 2013 13:40:24 +0100, Paul E Bennett
>> <Paul_E.Bennett@topmail.co.uk> wrote:
>>
>>> With the best will in the world, there is no electronics based technology
>>> that will last that long. It is hard enough doing designs that are
>>> required to have a life of 20 or 25 years with minimal (no) maintenance.
>>> After that time the equipment is replaced in major refurbishment
>>> programmes.
>>>
>>> Any component that relies on the long term stabiliity of chemistry will
>>> degrade and fail eventually.  Even in the mechanical world metals like
>>> Iron and Stainless Steel will change over time.
>>>
>>> Only in software can you achieve really long lifetimes (if you are careful
>>> about your design) but then what would you have left to run it on?
>>
>> Try looking at some serious long term infrastructure systems.  There is
>> plenty of SCADA that has already lasted as much as 60 years or more.  Lots
>> more in heavy industries (refining, major metal mills, chemical plants,
>> water treatment, wastewater treatment, etc.,) where replacement costs get
>> really really big.
>
> I don't suppose that those systems are still running without having had some
> maintenance (board swaps, repairs etc). Would you wish to guarantee that any
> system you design today will still be operating that far in the future.
>
> I don't know where your utilities are based but I am certain that the ones
> near me have all upgraded their systems over the years (just to cope with
> demands).

They've been replacing natural gas lines throughout the neighborhood
and certain parts of town.  Years ago, they started replacing the
individual "service drops" for each residence (interesting process!).
Then, last year, started replacing (and upgrading) the "mains" that
feed the neighborhood (even *more* interesting process!).

The former was part of a regular upgrade process -- original lines
were ~30 years old.

It's unclear if the latter was also part of "scheduled maintenance"
or, instead, reflected a city-wide gas shortage a couple of winters
ago (simply didn't have enough distribution capacity to cope with
an unusually cold spell and ended up having to turn off the supplies
to parts of the city so that other parts of the city had ample
pressure).

Interesting situation to find yourself without *gas*.  Electricity
you aren't terribly surprised to find it "out" (though rare, here).
Losing water tends to raise eyebrows as it is REALLY rare.  Gas
even more so!  The only utility (interesting observation, this!)
that you *never* expect to lose is *phone* (land line).

[Having lost it, once -- nearby lightning strike fried the electronic
phones on our service -- it was really unnerving.  You just NEVER
expect to lift the handset and NOT get dialtone!  Gotta wonder how
many 9's in *their* availability figures!  :> ]

On 10/17/2013 9:16 AM, Don Y wrote:
> Hi Paul,
>
> On 10/17/2013 12:32 AM, Paul E Bennett wrote:
>> josephkk wrote:
>>
>>> On Tue, 15 Oct 2013 13:40:24 +0100, Paul E Bennett
>>> <Paul_E.Bennett@topmail.co.uk> wrote:
>>>
>>>> With the best will in the world, there is no electronics based
>>>> technology
>>>> that will last that long. It is hard enough doing designs that are
>>>> required to have a life of 20 or 25 years with minimal (no)
>>>> maintenance.
>>>> After that time the equipment is replaced in major refurbishment
>>>> programmes.
>>>>
>>>> Any component that relies on the long term stabiliity of chemistry will
>>>> degrade and fail eventually.  Even in the mechanical world metals like
>>>> Iron and Stainless Steel will change over time.
>>>>
>>>> Only in software can you achieve really long lifetimes (if you are
>>>> careful
>>>> about your design) but then what would you have left to run it on?
>>>
>>> Try looking at some serious long term infrastructure systems.  There is
>>> plenty of SCADA that has already lasted as much as 60 years or more.
>>> Lots
>>> more in heavy industries (refining, major metal mills, chemical plants,
>>> water treatment, wastewater treatment, etc.,) where replacement costs
>>> get
>>> really really big.
>>
>> I don't suppose that those systems are still running without having
>> had some
>> maintenance (board swaps, repairs etc). Would you wish to guarantee
>> that any
>> system you design today will still be operating that far in the future.
>>
>> I don't know where your utilities are based but I am certain that the
>> ones
>> near me have all upgraded their systems over the years (just to cope with
>> demands).
>
> They've been replacing natural gas lines throughout the neighborhood
> and certain parts of town.  Years ago, they started replacing the
> individual "service drops" for each residence (interesting process!).
> Then, last year, started replacing (and upgrading) the "mains" that
> feed the neighborhood (even *more* interesting process!).
>
> The former was part of a regular upgrade process -- original lines
> were ~30 years old.
>
> It's unclear if the latter was also part of "scheduled maintenance"
> or, instead, reflected a city-wide gas shortage a couple of winters
> ago (simply didn't have enough distribution capacity to cope with
> an unusually cold spell and ended up having to turn off the supplies
> to parts of the city so that other parts of the city had ample
> pressure).
>
> Interesting situation to find yourself without *gas*.  Electricity
> you aren't terribly surprised to find it "out" (though rare, here).
> Losing water tends to raise eyebrows as it is REALLY rare.  Gas
> even more so!  The only utility (interesting observation, this!)
> that you *never* expect to lose is *phone* (land line).
>
> [Having lost it, once -- nearby lightning strike fried the electronic
> phones on our service -- it was really unnerving.  You just NEVER
> expect to lift the handset and NOT get dialtone!  Gotta wonder how
> many 9's in *their* availability figures!  :> ]

NYC just finished the replacement for the 1917 aqueduct.  Big job.

We've never had the gas or the water go out, but as far as phones go, 
you live a very sheltered life.  We finally bailed on POTS, despite the 
very great theoretical advantages of central-office power, because the 
Verizon people we had to deal with were so uniformly incompetent.

Getting anything changed, or trying to get them to grasp the concept of 
starting a home business and then moving to commercial space, took 
several phone calls and at least a few hours of pain per time.  They 
apparently had no method whatsoever for having one person understand 
what the actual task or problem was, or even for making notes.  It all 
had to be rehashed again each phone call, to a not-very-motivated and 
not-very-bright listener.  I suppose that nobody who could find another 
job would work there. (At one point we did find one guy who actually 
cared, and knew how to get things done, but he worked on the other side 
of their Chinese wall between commercial and residential accounts.)

I eventually concluded that an organization that incompetent couldn't 
really be relied upon to look after their central office batteries 
either.  So we eventually changed to cable, and keep spare batteries for 
our cell phones.

The Verizon sales reps call at the office a couple of times a year to 
ask me to switch to their service, and they're always confused when I 
burst out laughing.

Cheers

Phil Hobbs

-- 
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510 USA
+1 845 480 2058

hobbs at electrooptical dot net
http://electrooptical.net

Hi Phil,

On 10/17/2013 7:09 AM, Phil Hobbs wrote:
> On 10/17/2013 9:16 AM, Don Y wrote:
>> Interesting situation to find yourself without *gas*.  Electricity
>> you aren't terribly surprised to find it "out" (though rare, here).
>> Losing water tends to raise eyebrows as it is REALLY rare.  Gas
>> even more so!  The only utility (interesting observation, this!)
>> that you *never* expect to lose is *phone* (land line).
>>
>> [Having lost it, once -- nearby lightning strike fried the electronic
>> phones on our service -- it was really unnerving.  You just NEVER
>> expect to lift the handset and NOT get dialtone!  Gotta wonder how
>> many 9's in *their* availability figures!  :> ]
>
> NYC just finished the replacement for the 1917 aqueduct.  Big job.
>
> We've never had the gas or the water go out, but as far as phones go,
> you live a very sheltered life.  We finally bailed on POTS, despite the
> very great theoretical advantages of central-office power, because the
> Verizon people we had to deal with were so uniformly incompetent.

I've lived in 5 different states and never had a phone issue aside
from the lightning strike (in Colorado).  I had a flakey connection
in Chicagoland, once -- but traced it to a length of cable that had
fallen on the exhaust plenum for the gas furnace (the wire was nice
and toasty-crunchy!  :> ).  Lots of *noise* on this (below grade)
line in the days when I used a modem -- but that was traced to
water migration in the buried cable.

In each case (save the Colorado one), I was still able to make and
receive calls on the line.

As to the competence of the folks we have had to deal with "in the
sales office", that's another story.  Took us *6* calls to get our
DSL disconnected.  And, in the process, they managed to disconnect
our *phone* as well!  (the 6th call was to get phone service restored).

Always nice to see the "this phone call may be recorded for quality
purposes" come back to bite them in the ass, later!  :>

> Getting anything changed, or trying to get them to grasp the concept of
> starting a home business and then moving to commercial space, took
> several phone calls and at least a few hours of pain per time.  They
> apparently had no method whatsoever for having one person understand
> what the actual task or problem was, or even for making notes.  It all
> had to be rehashed again each phone call, to a not-very-motivated and
> not-very-bright listener.  I suppose that nobody who could find another
> job would work there. (At one point we did find one guy who actually
> cared, and knew how to get things done, but he worked on the other side
> of their Chinese wall between commercial and residential accounts.)
>
> I eventually concluded that an organization that incompetent couldn't
> really be relied upon to look after their central office batteries
> either.  So we eventually changed to cable, and keep spare batteries for
> our cell phones.

So, you've never actually LOST dialtone?

Neighbors routinely lose their cable service.  I wouldn't rely on it
for a "reliable" connection.  A friend was recently spooked when she
was having "chest pains" and found her cell phone unreliable -- and
no "land line" alternative available!

And, we don't use cell phones (why have to own *two* phone services
just to protect against *one* -- or both! -- being unavailable?)
In some areas, TPC is replacing copper "land line" circuits with
wireless.  Wanna bet they don't give the same availability levels??

You might find the folks who do the actual plant maintenance are
of a different caliber than the sales droid/order takers (which,
at least here, are located in another *state*!).

E.g., when I was having line noise problems, the tech that came
out to check the line initially saw "good numbers" and was puzzled
at the complaints I was making (I sat outside with him while he was
checking the line).  He sat and watched the line for perhaps 15
minutes before the noise floor shot up dramatically:  "Holy cow!
Can you even *talk* on that line??"  (Yes, but a 56K modem can't!)

Of course, the only solution he had was to switch us to a different
pair...

> The Verizon sales reps call at the office a couple of times a year to
> ask me to switch to their service, and they're always confused when I
> burst out laughing.

On Thu, 17 Oct 2013 10:09:09 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
<snip>

>NYC just finished the replacement for the 1917 aqueduct.  Big job.
>
>We've never had the gas or the water go out, but as far as phones go, 
>you live a very sheltered life.  We finally bailed on POTS, despite the 
>very great theoretical advantages of central-office power, because the 
>Verizon people we had to deal with were so uniformly incompetent.
>
>Getting anything changed, or trying to get them to grasp the concept of 
>starting a home business and then moving to commercial space, took 
>several phone calls and at least a few hours of pain per time.  They 
>apparently had no method whatsoever for having one person understand 
>what the actual task or problem was, or even for making notes.  It all 
>had to be rehashed again each phone call, to a not-very-motivated and 
>not-very-bright listener.  I suppose that nobody who could find another 
>job would work there. (At one point we did find one guy who actually 
>cared, and knew how to get things done, but he worked on the other side 
>of their Chinese wall between commercial and residential accounts.)
>
>I eventually concluded that an organization that incompetent couldn't 
>really be relied upon to look after their central office batteries 
>either.  So we eventually changed to cable, and keep spare batteries for 
>our cell phones.
>
>The Verizon sales reps call at the office a couple of times a year to 
>ask me to switch to their service, and they're always confused when I 
>burst out laughing.
>
>Cheers
>
>Phil Hobbs

Welcome to the wonderful world of unions!  You can't fire them, you
can't discipline them, all you can do is put them in a job where they
can't cause too much damage... :-(

Actually, CO's usually have very good maintanance.  They have
'routines' that need to be performed every so often on a schedule,
that are then verified on a similiar schedule.  A lot of things are
also automated, but most important, the jobs are 'interesting' so the
tech's usually care a bit about how things go...

On Thu, 17 Oct 2013 06:16:10 -0700, Don Y <this@isnotme.com> wrote:

>
>Interesting situation to find yourself without *gas*.  Electricity
>you aren't terribly surprised to find it "out" (though rare, here).
>Losing water tends to raise eyebrows as it is REALLY rare.  Gas
>even more so!  The only utility (interesting observation, this!)
>that you *never* expect to lose is *phone* (land line).

All this stuff will die fairly quickly (days) if there is a severe
problem. If that ever happens, those folks affected are going to be in
a world of hurt. Once the water supply fails, the wastewater treatment
won't be far behind because it depends on a continous flow of water.
This might be the real threat of EMP and the weapons (carbon
filaments, smart bombs) that destroy electrical and water treatment
systems- by taking out utilities over a wide area, people will start
to die within weeks and they'll be in no mood to do anything but try
to keep themselves alive. 

I've never seen an unexpected loss of natural gas or water pressure
(i.e. not due to scheduled repairs or maintenance). I imagine a water
main bursting would result in a loss of pressure to some homes and
businesses. Not paying bills might result in a sudden loss of gas
pressure. ;-) 

The last little bit of phone line is more prone to problems, IME. POTS
must be 100-1000x more reliable than internet based services. OTOH, we
have many options to POTS these days, so a single point failure isn't
devastating.  

Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> writes:

> On Thu, 17 Oct 2013 06:16:10 -0700, Don Y <this@isnotme.com> wrote:
>
>>
>>Interesting situation to find yourself without *gas*.  Electricity
>>you aren't terribly surprised to find it "out" (though rare, here).
>>Losing water tends to raise eyebrows as it is REALLY rare.  Gas
>>even more so!  The only utility (interesting observation, this!)
>>that you *never* expect to lose is *phone* (land line).
>
> All this stuff will die fairly quickly (days) if there is a severe
> problem. If that ever happens, those folks affected are going to be in
> a world of hurt. Once the water supply fails, the wastewater treatment
> won't be far behind because it depends on a continous flow of water.
> This might be the real threat of EMP and the weapons (carbon
> filaments, smart bombs) that destroy electrical and water treatment
> systems- by taking out utilities over a wide area, people will start
> to die within weeks and they'll be in no mood to do anything but try
> to keep themselves alive. 
>
> I've never seen an unexpected loss of natural gas or water pressure
> (i.e. not due to scheduled repairs or maintenance). I imagine a water
> main bursting would result in a loss of pressure to some homes and
> businesses. Not paying bills might result in a sudden loss of gas
> pressure. ;-) 

We had water cut off for two weeks... floods inundated the regional
waterworks, located close to the river of course. Contaminating the
water treatment tanks with raw sewage. 

Yummy!

[...]

<https://www.google.com/search?q=tewkesbury+floods&tbm=isch>


-- 

John Devereux