Any special issues/handling related to using these devices in designs?

On Mon, 5 Jul 2021 09:34:46 -0700, Don Y <blockedofcourse@foo.invalid>
wrote:

>Any special issues/handling related to using these devices in designs?

Which mems? There are lots of them.

--

John Larkin Highland Technology, Inc

The best designs are necessarily accidental.

On Monday, 5 July 2021 at 17:37:42 UTC+1, jla...@highlandsniptechnology.com wrote:
> On Mon, 5 Jul 2021 09:34:46 -0700, Don Y <blocked...@foo.invalid>
> wrote:
> >Any special issues/handling related to using these devices in designs?
> Which mems? There are lots of them.
>
Some MEMS oscillators stop oscillating when exposed to helium gas. They
recover a few weeks later. There are other designs that are immune.

John

John Walliker wrote:
> On Monday, 5 July 2021 at 17:37:42 UTC+1, jla...@highlandsniptechnology.com wrote:
>> On Mon, 5 Jul 2021 09:34:46 -0700, Don Y <blocked...@foo.invalid>
>> wrote:
>>> Any special issues/handling related to using these devices in designs?
>> Which mems? There are lots of them.
>>
> Some MEMS oscillators stop oscillating when exposed to helium gas. They
> recover a few weeks later. There are other designs that are immune.
>
> John
>
Then there are digital micromirror devices (DMDs) used for projectors,
MEMS galvo scanners, diffractive MEMS add/drop couplers for telecoms,
MEMS relays, and on and on.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On Mon, 5 Jul 2021 13:17:59 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>John Walliker wrote:
>> On Monday, 5 July 2021 at 17:37:42 UTC+1, jla...@highlandsniptechnology.com wrote:
>>> On Mon, 5 Jul 2021 09:34:46 -0700, Don Y <blocked...@foo.invalid>
>>> wrote:
>>>> Any special issues/handling related to using these devices in designs?
>>> Which mems? There are lots of them.
>>>
>> Some MEMS oscillators stop oscillating when exposed to helium gas. They
>> recover a few weeks later. There are other designs that are immune.
>>
>> John
>>
>Then there are digital micromirror devices (DMDs) used for projectors,
>MEMS galvo scanners, diffractive MEMS add/drop couplers for telecoms,
>MEMS relays, and on and on.
>
>Cheers
>
>Phil Hobbs

Microphones and accelerometers too.

MEMS relays were very promising once, but were apparently unreliable.

Pity.

John Larkin wrote:
> On Mon, 5 Jul 2021 13:17:59 -0400, Phil Hobbs
> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>
>> John Walliker wrote:
>>> On Monday, 5 July 2021 at 17:37:42 UTC+1, jla...@highlandsniptechnology.com wrote:
>>>> On Mon, 5 Jul 2021 09:34:46 -0700, Don Y <blocked...@foo.invalid>
>>>> wrote:
>>>>> Any special issues/handling related to using these devices in designs?
>>>> Which mems? There are lots of them.
>>>>
>>> Some MEMS oscillators stop oscillating when exposed to helium gas. They
>>> recover a few weeks later. There are other designs that are immune.
>>>
>>> John
>>>
>> Then there are digital micromirror devices (DMDs) used for projectors,
>> MEMS galvo scanners, diffractive MEMS add/drop couplers for telecoms,
>> MEMS relays, and on and on.
>>
>> Cheers
>>
>> Phil Hobbs
>
> Microphones and accelerometers too.
>
> MEMS relays were very promising once, but were apparently unreliable.
>
> Pity.
>

Yeah, the intersection of good MEMs metals and good contact metals
turned out to be the null set. :(

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On 7/5/2021 10:15 AM, John Walliker wrote:
> Some MEMS oscillators stop oscillating when exposed to helium gas. They
> recover a few weeks later. There are other designs that are immune.

Yes, a colleague mentioned that -- though not just confined to
oscillators. Basically, any device that "thinks" it is operating
in a vacuum (sealed cavity) is vulnerable to He infusion through
"inadequate"? device seals.

The "recovery" is waiting for the He to leak back out (though
biases can persist as this is an imperfect process).

Surprisingly, he mentioned that even low concentrations of He
can be problematic!

[My question to him: what's the environmental He source that
you're leary of?]

On Mon, 5 Jul 2021 13:47:23 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>John Larkin wrote:
>> On Mon, 5 Jul 2021 13:17:59 -0400, Phil Hobbs
>> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>>
>>> John Walliker wrote:
>>>> On Monday, 5 July 2021 at 17:37:42 UTC+1, jla...@highlandsniptechnology.com wrote:
>>>>> On Mon, 5 Jul 2021 09:34:46 -0700, Don Y <blocked...@foo.invalid>
>>>>> wrote:
>>>>>> Any special issues/handling related to using these devices in designs?
>>>>> Which mems? There are lots of them.
>>>>>
>>>> Some MEMS oscillators stop oscillating when exposed to helium gas. They
>>>> recover a few weeks later. There are other designs that are immune.
>>>>
>>>> John
>>>>
>>> Then there are digital micromirror devices (DMDs) used for projectors,
>>> MEMS galvo scanners, diffractive MEMS add/drop couplers for telecoms,
>>> MEMS relays, and on and on.
>>>
>>> Cheers
>>>
>>> Phil Hobbs
>>
>> Microphones and accelerometers too.
>>
>> MEMS relays were very promising once, but were apparently unreliable.
>>
>> Pity.
>>
>
>Yeah, the intersection of good MEMs metals and good contact metals
>turned out to be the null set. :(
>
>Cheers
>
>Phil Hobbs

Like reed relays. Clean metals cold-weld, and with low separation
forces tend to stick.

Maybe that's another perversity of nature, good electrical contact
materials stick.

Why not build in an unstick shaker?

On Mon, 5 Jul 2021 11:42:31 -0700, Don Y <blockedofcourse@foo.invalid>
wrote:

>On 7/5/2021 10:15 AM, John Walliker wrote:
>> Some MEMS oscillators stop oscillating when exposed to helium gas. They
>> recover a few weeks later. There are other designs that are immune.
>
>Yes, a colleague mentioned that -- though not just confined to
>oscillators. Basically, any device that "thinks" it is operating
>in a vacuum (sealed cavity) is vulnerable to He infusion through
>"inadequate"? device seals.
>
>The "recovery" is waiting for the He to leak back out (though
>biases can persist as this is an imperfect process).
>
>Surprisingly, he mentioned that even low concentrations of He
>can be problematic!

Yes, a few percent of He gas in boil-off killed my iPhone 10 on
several occasions. VERY irritating until I found out what it was
(ended up replacing the phone twice).

>[My question to him: what's the environmental He source that
>you're leary of?]

In my case, it was when they went from 77K to 4.2K in the crystat that
a lot of He was boiled off.
--
Best regards,
Spehro Pefhany

mandag den 5. juli 2021 kl. 18.34.54 UTC+2 skrev Don Y:
> Any special issues/handling related to using these devices in designs?

I believe ultrasonic cleaning can damage or destroy some mems devices

mandag den 5. juli 2021 kl. 21.34.27 UTC+2 skrev Spehro Pefhany:
> On Mon, 5 Jul 2021 11:42:31 -0700, Don Y <blocked...@foo.invalid>
> wrote:
> >On 7/5/2021 10:15 AM, John Walliker wrote:
> >> Some MEMS oscillators stop oscillating when exposed to helium gas. They
> >> recover a few weeks later. There are other designs that are immune.
> >
> >Yes, a colleague mentioned that -- though not just confined to
> >oscillators. Basically, any device that "thinks" it is operating
> >in a vacuum (sealed cavity) is vulnerable to He infusion through
> >"inadequate"? device seals.
> >
> >The "recovery" is waiting for the He to leak back out (though
> >biases can persist as this is an imperfect process).
> >
> >Surprisingly, he mentioned that even low concentrations of He
> >can be problematic!
> Yes, a few percent of He gas in boil-off killed my iPhone 10 on
> several occasions. VERY irritating until I found out what it was
> (ended up replacing the phone twice).
> >[My question to him: what's the environmental He source that
> >you're leary of?]
> In my case, it was when they went from 77K to 4.2K in the crystat that
> a lot of He was boiled off.

https://youtu.be/vvzWaVvB908

On 7/5/2021 12:34 PM, Spehro Pefhany wrote:
> On Mon, 5 Jul 2021 11:42:31 -0700, Don Y <blockedofcourse@foo.invalid>
> wrote:
>
>> On 7/5/2021 10:15 AM, John Walliker wrote:
>>> Some MEMS oscillators stop oscillating when exposed to helium gas. They
>>> recover a few weeks later. There are other designs that are immune.
>>
>> Yes, a colleague mentioned that -- though not just confined to
>> oscillators. Basically, any device that "thinks" it is operating
>> in a vacuum (sealed cavity) is vulnerable to He infusion through
>> "inadequate"? device seals.
>>
>> The "recovery" is waiting for the He to leak back out (though
>> biases can persist as this is an imperfect process).
>>
>> Surprisingly, he mentioned that even low concentrations of He
>> can be problematic!
>
> Yes, a few percent of He gas in boil-off killed my iPhone 10 on
> several occasions. VERY irritating until I found out what it was
> (ended up replacing the phone twice).

But, you can't really fault Apple for that "usage constraint"
(even if they didn't put an explicit disclaimer on the box!)

>> [My question to him: what's the environmental He source that
>> you're leary of?]
>
> In my case, it was when they went from 77K to 4.2K in the crystat that
> a lot of He was boiled off.

I've not received a reply from my friend. That's "code" for
"Don't ask, I can't tell you!" -- which makes me doubly curious
as to the market he's addressing! :-/

On 7/5/2021 12:38 PM, Lasse Langwadt Christensen wrote:
> mandag den 5. juli 2021 kl. 18.34.54 UTC+2 skrev Don Y:
>> Any special issues/handling related to using these devices in designs?
>
> I believe ultrasonic cleaning can damage or destroy some mems devices

That would make sense. But, aside from manufacturing, it
would be hard to imagine a typical application domain where a
"device" would typically be ultrasonic cleaned.

On Mon, 5 Jul 2021 14:57:21 -0700, Don Y <blockedofcourse@foo.invalid>
wrote:

>On 7/5/2021 12:34 PM, Spehro Pefhany wrote:
>> On Mon, 5 Jul 2021 11:42:31 -0700, Don Y <blockedofcourse@foo.invalid>
>> wrote:
>>
>>> On 7/5/2021 10:15 AM, John Walliker wrote:
>>>> Some MEMS oscillators stop oscillating when exposed to helium gas. They
>>>> recover a few weeks later. There are other designs that are immune.
>>>
>>> Yes, a colleague mentioned that -- though not just confined to
>>> oscillators. Basically, any device that "thinks" it is operating
>>> in a vacuum (sealed cavity) is vulnerable to He infusion through
>>> "inadequate"? device seals.
>>>
>>> The "recovery" is waiting for the He to leak back out (though
>>> biases can persist as this is an imperfect process).
>>>
>>> Surprisingly, he mentioned that even low concentrations of He
>>> can be problematic!
>>
>> Yes, a few percent of He gas in boil-off killed my iPhone 10 on
>> several occasions. VERY irritating until I found out what it was
>> (ended up replacing the phone twice).
>
>But, you can't really fault Apple for that "usage constraint"
>(even if they didn't put an explicit disclaimer on the box!)

The self-proclaimed geniuses at the 'Genius Bar' didn't have a clue
either.

>
>>> [My question to him: what's the environmental He source that
>>> you're leary of?]
>>
>> In my case, it was when they went from 77K to 4.2K in the crystat that
>> a lot of He was boiled off.
>
>I've not received a reply from my friend. That's "code" for
>"Don't ask, I can't tell you!" -- which makes me doubly curious
>as to the market he's addressing! :-/
--
Best regards,
Spehro Pefhany

On Mon, 5 Jul 2021 14:58:48 -0700, Don Y <blockedofcourse@foo.invalid>
wrote:

>On 7/5/2021 12:38 PM, Lasse Langwadt Christensen wrote:
>> mandag den 5. juli 2021 kl. 18.34.54 UTC+2 skrev Don Y:
>>> Any special issues/handling related to using these devices in designs?
>>
>> I believe ultrasonic cleaning can damage or destroy some mems devices
>
>That would make sense. But, aside from manufacturing, it
>would be hard to imagine a typical application domain where a
>"device" would typically be ultrasonic cleaned.

Maybe if you're making a sensor for auto-tuning ultrasonic cleaner
drivers.

;-)
--
Best regards,
Spehro Pefhany

On Mon, 5 Jul 2021 12:38:59 -0700 (PDT), Lasse Langwadt Christensen
<langwadt@fonz.dk> wrote:

>mandag den 5. juli 2021 kl. 18.34.54 UTC+2 skrev Don Y:
>> Any special issues/handling related to using these devices in designs?
>
>I believe ultrasonic cleaning can damage or destroy some mems devices

We have bought XOs (not mems) that have warnings against ultrasonic
cleaning.

Does anyone use ultrasonic cleaning for electronics?

--

John Larkin Highland Technology, Inc

The best designs are necessarily accidental.

On 06/07/2021 04:42, Don Y wrote:
> On 7/5/2021 10:15 AM, John Walliker wrote:
>> Some MEMS oscillators stop oscillating when exposed to helium gas.  They
>> recover a few weeks later.  There are other designs that are immune.
>
> Yes, a colleague mentioned that -- though not just confined to
> oscillators.  Basically, any device that "thinks" it is operating
> in a vacuum (sealed cavity) is vulnerable to He infusion through
> "inadequate"? device seals.
>
> The "recovery" is waiting for the He to leak back out (though
> biases can persist as this is an imperfect process).
>
> Surprisingly, he mentioned that even low concentrations of He
> can be problematic!
>
> [My question to him:  what's the environmental He source that
> you're leary of?]

MRI machines? Balloon shops?

On Monday, July 5, 2021 at 12:05:36 PM UTC-7, John Larkin wrote:

> Like reed relays. Clean metals cold-weld, and with low separation
> forces tend to stick.

Stickiness doesn't argue against reed relays; you can unstick 'em by
applying two N poles to the ends, and creating magnetic repulsion.
It just depends on how you choose to drive them.

On 2021-07-06 09:26, whit3rd wrote:
> On Monday, July 5, 2021 at 12:05:36 PM UTC-7, John Larkin wrote:
>
>> Like reed relays. Clean metals cold-weld, and with low separation
>> forces tend to stick.
>
> Stickiness doesn't argue against reed relays; you can unstick 'em by
> applying two N poles to the ends, and creating magnetic repulsion.
> It just depends on how you choose to drive them.
>

Oh, that's very practical when you have hundreds of them in
remotely controlled instruments.

That said, in fact my experience with Elfein and Pickering reed
switches has been excellent, with many switches having exceeded
500M operations without failures. Au contraire, the miniature
Omron SPDT SMD relays have been miserable right from the start.
The docs don't say you can't wash them.

Jeroen Belleman

On Tue, 06 Jul 2021 10:24:21 +0200, Jeroen Belleman
<jeroen@nospam.please> wrote:

>On 2021-07-06 09:26, whit3rd wrote:
>> On Monday, July 5, 2021 at 12:05:36 PM UTC-7, John Larkin wrote:
>>
>>> Like reed relays. Clean metals cold-weld, and with low separation
>>> forces tend to stick.
>>
>> Stickiness doesn't argue against reed relays; you can unstick 'em by
>> applying two N poles to the ends, and creating magnetic repulsion.
>> It just depends on how you choose to drive them.
>>
>
>Oh, that's very practical when you have hundreds of them in
>remotely controlled instruments.
>
>That said, in fact my experience with Elfein and Pickering reed
>switches has been excellent, with many switches having exceeded
>500M operations without failures. Au contraire, the miniature
>Omron SPDT SMD relays have been miserable right from the start.
>The docs don't say you can't wash them.
>
>Jeroen Belleman

We've used over 100K of the Fujitsu equivalent, regular and latching,
and they have been fine. But don't water wash them either. Solvent is
OK.

We're going all no-clean anyhow.

DPDT is cool. You can build matrix trees, range switches, flying
capacitors, all sorts of stuff. See AoE3 p 360.

--

John Larkin Highland Technology, Inc

The best designs are necessarily accidental.

On 06/07/2021 01:06, jlarkin@highlandsniptechnology.com wrote:
> On Mon, 5 Jul 2021 12:38:59 -0700 (PDT), Lasse Langwadt Christensen
> <langwadt@fonz.dk> wrote:
>
>> mandag den 5. juli 2021 kl. 18.34.54 UTC+2 skrev Don Y:
>>> Any special issues/handling related to using these devices in designs?
>>
>> I believe ultrasonic cleaning can damage or destroy some mems devices
>
> We have bought XOs (not mems) that have warnings against ultrasonic
> cleaning.
>
> Does anyone use ultrasonic cleaning for electronics?

It was thought at one time that there might be an issue with flux
residue becoming a little conductive at high temperatures. I don't know
if that was ever proved, but for a while at least, ultrasonic cleaning
was supposed to be the solution for repair work.

--
Cheers
Clive

On Tuesday, July 6, 2021 at 1:24:27 AM UTC-7, Jeroen Belleman wrote:
> On 2021-07-06 09:26, whit3rd wrote:
> > On Monday, July 5, 2021 at 12:05:36 PM UTC-7, John Larkin wrote:
> >
> >> Like reed relays. Clean metals cold-weld, and with low separation
> >> forces tend to stick.
> >
> > Stickiness doesn't argue against reed relays; you can unstick 'em by
> > applying two N poles to the ends, and creating magnetic repulsion.
> > It just depends on how you choose to drive them.
> >
> Oh, that's very practical when you have hundreds of them in
> remotely controlled instruments.

Yes, of course it is; it's how a reed would be configured for
latching-relay use, with a suitable magnetizable armature.

Or, you could unstick one by hand with a couple of cow magnets, I suppose.

<https://www.exploratoriumstore.com/products/cow-magnet>

On Tuesday, 6 July 2021 at 18:32:25 UTC+1, whit3rd wrote:

>
> Or, you could unstick one by hand with a couple of cow magnets, I suppose.
>
> <https://www.exploratoriumstore.com/products/cow-magnet>

I had never come across the idea of feeding magnets to cows before.
Feeding them to children seems to have caused a few deaths.

John

On 07/07/2021 2:23 am, John Walliker wrote:
> On Tuesday, 6 July 2021 at 18:32:25 UTC+1, whit3rd wrote:
>
>>
>> Or, you could unstick one by hand with a couple of cow magnets, I suppose.
>>
>> <https://www.exploratoriumstore.com/products/cow-magnet>
>
> I had never come across the idea of feeding magnets to cows before.
> Feeding them to children seems to have caused a few deaths.
>
> John
>

Been doing that with cows for years.

gray_wolf wrote:
> On 07/07/2021 2:23 am, John Walliker wrote:
>> On Tuesday, 6 July 2021 at 18:32:25 UTC+1, whit3rd wrote:
>>
>>>
>>> Or, you could unstick one by hand with a couple of cow magnets, I
>>> suppose.
>>>
>>> <https://www.exploratoriumstore.com/products/cow-magnet>
>>
>> I had never come across the idea of feeding magnets to cows before.
>> Feeding them to children seems to have caused a few deaths.
>>
>> John
>>
>
> Been doing that with cows for years.

Plus you can stick them on your fuel lines and get 200 MPG. ;)

Cheers

Phil Hobbs