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| Archimedes' Lever... |
 Posted: Wed Nov 04, 2009 7:09 am |
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On Tue, 3 Nov 2009 18:22:04 -0800 (PST), "J.A. Legris"
<jalegris at (no spam) sympatico.ca> wrote:
[quote]On Nov 3, 7:33 pm, Archimedes' Lever <OneBigLe... at (no spam) InfiniteSeries.Org
wrote:
On Tue, 3 Nov 2009 07:01:38 -0800 (PST), "J.A. Legris"
jaleg... at (no spam) sympatico.ca> wrote:
5) Environmentally unfriendly: for you, the customer and everyone
else.
Cured potting compounds pose no environmental threat (nearly all), and
even when uncured they only pose a threat to the environment if you or
another of your dopes gets the shit all over the place.
Use some brains.,
I did, which is why I no longer use potting compounds. The problem is
dopes like you who cannot reason beyond their next paycheck.
[/quote]
You're a goddamned retard.
[quote]The long-
term effects of most synthetic chemicals have never been
comprehensively assessed,
[/quote]
Not with a dope like you at the wheel, but yes, there are long term
studies, and there is long term knowledge in the industry, you stupid
pussified twit.
[quote]so erring on the side of caution is the wise
thing to do.
[/quote]
You're a goddamned long term stye on the face of intelligent men of the
world. You meant to say "Being a PUSSY on the "side of caution" is a
stupid way to achieve 'progress'".
You are probably so retarded that you embrace RoHS, and you think that
metallic form lead is a problem for the environment.
If it were, the lead levels in water tables around lead mining and also
around land fills and especially around decades old police shooting
ranges would show higher numbers and they do NOT.
Idiots like you are pathetic. |
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| J.A. Legris... |
| Posted: Wed Nov 04, 2009 7:10 am |
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Guest
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On Nov 4, 11:28 am, D from BC <myrealaddr... at (no spam) comic.com> wrote:
[quote]On Wed, 04 Nov 2009 04:01:10 -0800, Archimedes' Lever
OneBigLe... at (no spam) InfiniteSeries.Org> wrote:
On Tue, 3 Nov 2009 18:04:35 -0800 (PST), "J.A. Legris"
jaleg... at (no spam) sympatico.ca> wrote:
On Nov 3, 7:31 pm, Archimedes' Lever <OneBigLe... at (no spam) InfiniteSeries.Org
wrote:
On Tue, 3 Nov 2009 07:01:38 -0800 (PST), "J.A. Legris"
jaleg... at (no spam) sympatico.ca> wrote:
3) Diagnostics and repair. How do you diagnose an encapsulated device
that fails. How do you repair it?
Pitch and replace. Doh! Some products cost far more to service than
to simply replace, and that includes even many that are not ever
encapsulated.
Some of us are interested in knowing why their products fail.
Some of us? You're a goddamned idiot for that snide remark. ALL of us
like just statistics.
In fact,
I attribute my success, in part, to just such an attitude.
Yes, but you apparently have no clue about hard potted devices.
If it is that small a device, you should already know all about every
failure mode there is for it, and that should be able to be determined
without examination in many cases. All you should need is your prior
knowledge of the circuit operation and the particulars of the failure.
If it is a power supply device and it is failing, you should not be
selling it as a product to begin with. A PROVEN design, will have all of
its failure modes documented. Any potted design should be a proven
design, especially if the potting is meant for IP security purposes.
Otherwise, a serviceable potting would be needed.
If you are selling hard potted products, you have already resolved to
full replacement upon failure.
Why a PS device would need IP security is the real question. Why this
dope thinks his supply circuit is so special that someone would be on his
heels to copy it is beyond me. If it is that revolutionary, he should
patent it, and SELL the design to a bigger player in the industry.
DUH
I've yet to find my design on the net nor in chip form.
I figure the lazy cheap 'just in case' action is to pot the
electronics in my product until it makes enough money for me to afford
a patent guy to do all the patent searching, applying,patent write
up,defending,offending and license granting...and maybe to run out to
get coffee sometimes.
[/quote]
IIRC you should apply for the patent before you release the product
(or even just keep it secret) or you may lose your rights. This
presumes patenting the thing is a good idea in the first place - which
is unlikely unless you have deep pockets.
http://en.wikipedia.org/wiki/Prior_art
--
Joe |
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| Archimedes' Lever... |
| Posted: Wed Nov 04, 2009 7:29 am |
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Guest
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On Tue, 03 Nov 2009 19:56:51 -0800, D from BC <myrealaddress at (no spam) comic.com>
wrote:
[quote]On Tue, 3 Nov 2009 18:22:04 -0800 (PST), "J.A. Legris"
jalegris at (no spam) sympatico.ca> wrote:
On Nov 3, 7:33 pm, Archimedes' Lever <OneBigLe... at (no spam) InfiniteSeries.Org
wrote:
On Tue, 3 Nov 2009 07:01:38 -0800 (PST), "J.A. Legris"
jaleg... at (no spam) sympatico.ca> wrote:
5) Environmentally unfriendly: for you, the customer and everyone
else.
Cured potting compounds pose no environmental threat (nearly all), and
even when uncured they only pose a threat to the environment if you or
another of your dopes gets the shit all over the place.
Use some brains.,
I did, which is why I no longer use potting compounds. The problem is
dopes like you who cannot reason beyond their next paycheck. The long-
term effects of most synthetic chemicals have never been
comprehensively assessed, so erring on the side of caution is the wise
thing to do.
I'm wondering about thermal expansion.
My 1"x1" pcb that I want to encapsulate will be in an environment
where the temp may swing from 22C to 70C daily.
[/quote]
The expansion numbers on potting are for what happens during curing.
[quote]I have no idea if an epoxy encapsulant will flex with heat and shear
forces will push on the tiny smt parts..
[/quote]
Then conformally coat it BEFORE you pot it.
[quote]I'll try to find specs.
[/quote]
They are, of course, available. Stycast is a common potting media.
[quote]Perhaps testing in an environmental chamber is needed.
[/quote]
Not likely. A simple chamber with known temp is fine.
[quote]But I'm cheap, so I'll be using a light bulb in a box controlled by a
thermostat.
[/quote]
OK. |
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| D from BC... |
| Posted: Wed Nov 04, 2009 11:28 am |
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Guest
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On Wed, 04 Nov 2009 04:01:10 -0800, Archimedes' Lever
<OneBigLever at (no spam) InfiniteSeries.Org> wrote:
[quote]On Tue, 3 Nov 2009 18:04:35 -0800 (PST), "J.A. Legris"
jalegris at (no spam) sympatico.ca> wrote:
On Nov 3, 7:31 pm, Archimedes' Lever <OneBigLe... at (no spam) InfiniteSeries.Org
wrote:
On Tue, 3 Nov 2009 07:01:38 -0800 (PST), "J.A. Legris"
jaleg... at (no spam) sympatico.ca> wrote:
3) Diagnostics and repair. How do you diagnose an encapsulated device
that fails. How do you repair it?
Pitch and replace. Doh! Some products cost far more to service than
to simply replace, and that includes even many that are not ever
encapsulated.
Some of us are interested in knowing why their products fail.
Some of us? You're a goddamned idiot for that snide remark. ALL of us
like just statistics.
In fact,
I attribute my success, in part, to just such an attitude.
Yes, but you apparently have no clue about hard potted devices.
If it is that small a device, you should already know all about every
failure mode there is for it, and that should be able to be determined
without examination in many cases. All you should need is your prior
knowledge of the circuit operation and the particulars of the failure.
If it is a power supply device and it is failing, you should not be
selling it as a product to begin with. A PROVEN design, will have all of
its failure modes documented. Any potted design should be a proven
design, especially if the potting is meant for IP security purposes.
Otherwise, a serviceable potting would be needed.
If you are selling hard potted products, you have already resolved to
full replacement upon failure.
Why a PS device would need IP security is the real question. Why this
dope thinks his supply circuit is so special that someone would be on his
heels to copy it is beyond me. If it is that revolutionary, he should
patent it, and SELL the design to a bigger player in the industry.
DUH
[/quote]
I've yet to find my design on the net nor in chip form.
I figure the lazy cheap 'just in case' action is to pot the
electronics in my product until it makes enough money for me to afford
a patent guy to do all the patent searching, applying,patent write
up,defending,offending and license granting...and maybe to run out to
get coffee sometimes. |
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| D from BC... |
| Posted: Wed Nov 04, 2009 12:33 pm |
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Guest
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On Wed, 4 Nov 2009 09:10:48 -0800 (PST), "J.A. Legris"
<jalegris at (no spam) sympatico.ca> wrote:
[quote]IIRC you should apply for the patent before you release the product
(or even just keep it secret) or you may lose your rights. This
presumes patenting the thing is a good idea in the first place - which
is unlikely unless you have deep pockets.
http://en.wikipedia.org/wiki/Prior_art
[/quote]
It's not fair if I lose my patentability rights when I'd like to
release 200 units for ~field testing~ 
to tweek and finalize the design. |
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| J.A. Legris... |
| Posted: Wed Nov 04, 2009 5:46 pm |
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Guest
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On Nov 4, 12:33 pm, D from BC <myrealaddr... at (no spam) comic.com> wrote:
[quote]On Wed, 4 Nov 2009 09:10:48 -0800 (PST), "J.A. Legris"
jaleg... at (no spam) sympatico.ca> wrote:
IIRC you should apply for the patent before you release the product
(or even just keep it secret) or you may lose your rights. This
presumes patenting the thing is a good idea in the first place - which
is unlikely unless you have deep pockets.
http://en.wikipedia.org/wiki/Prior_art
It's not fair if I lose my patentability rights when I'd like to
release 200 units for ~field testing~
to tweek and finalize the design.
[/quote]
The wikipedia article mentions that you can protect your rights by
obtaining non-disclosure agreements.
--
Joe |
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| Archimedes' Lever... |
| Posted: Wed Nov 04, 2009 7:09 pm |
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Guest
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On Wed, 04 Nov 2009 09:33:45 -0800, D from BC <myrealaddress at (no spam) comic.com>
wrote:
[quote]On Wed, 4 Nov 2009 09:10:48 -0800 (PST), "J.A. Legris"
jalegris at (no spam) sympatico.ca> wrote:
IIRC you should apply for the patent before you release the product
(or even just keep it secret) or you may lose your rights. This
presumes patenting the thing is a good idea in the first place - which
is unlikely unless you have deep pockets.
http://en.wikipedia.org/wiki/Prior_art
It's not fair if I lose my patentability rights when I'd like to
release 200 units for ~field testing~
to tweek and finalize the design.
[/quote]
You can tweak the design at the bench by beating the hell out of a few
units, and being very good at recording and analysis of observed data. |
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| D from BC... |
| Posted: Wed Nov 04, 2009 7:32 pm |
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Guest
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On Wed, 04 Nov 2009 16:09:29 -0800, Archimedes' Lever
<OneBigLever at (no spam) InfiniteSeries.Org> wrote:
[quote]On Wed, 04 Nov 2009 09:33:45 -0800, D from BC <myrealaddress at (no spam) comic.com
wrote:
On Wed, 4 Nov 2009 09:10:48 -0800 (PST), "J.A. Legris"
jalegris at (no spam) sympatico.ca> wrote:
IIRC you should apply for the patent before you release the product
(or even just keep it secret) or you may lose your rights. This
presumes patenting the thing is a good idea in the first place - which
is unlikely unless you have deep pockets.
http://en.wikipedia.org/wiki/Prior_art
It's not fair if I lose my patentability rights when I'd like to
release 200 units for ~field testing~
to tweek and finalize the design.
You can tweak the design at the bench by beating the hell out of a few
units, and being very good at recording and analysis of observed data.
[/quote]
I'm just afraid my customers might do a better job at beating the hell
out my stuff more than I can.. |
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| Ken S. Tucker... |
| Posted: Thu Nov 05, 2009 1:08 pm |
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Guest
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On Nov 4, 7:46 pm, "J.A. Legris" <jaleg... at (no spam) sympatico.ca> wrote:
[quote]On Nov 4, 12:33 pm, D from BC <myrealaddr... at (no spam) comic.com> wrote:
On Wed, 4 Nov 2009 09:10:48 -0800 (PST), "J.A. Legris"
jaleg... at (no spam) sympatico.ca> wrote:
IIRC you should apply for the patent before you release the product
(or even just keep it secret) or you may lose your rights. This
presumes patenting the thing is a good idea in the first place - which
is unlikely unless you have deep pockets.
http://en.wikipedia.org/wiki/Prior_art
It's not fair if I lose my patentability rights when I'd like to
release 200 units for ~field testing~
to tweek and finalize the design.
The wikipedia article mentions that you can protect your rights by
obtaining non-disclosure agreements.
[/quote]
We spray paint our PCB's black, for a sealant and thermodynamic
(black-body) radiation, it also makes a direct copy difficult.
Ken |
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| MooseFET... |
| Posted: Thu Nov 05, 2009 4:42 pm |
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Guest
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On Nov 5, 4:19 pm, krw <k... at (no spam) att.bizzzzzzzzzzz> wrote:
[quote]On Thu, 5 Nov 2009 15:08:58 -0800 (PST), "Ken S. Tucker"
dynam... at (no spam) vianet.on.ca> wrote:
On Nov 4, 7:46 pm, "J.A. Legris" <jaleg... at (no spam) sympatico.ca> wrote:
On Nov 4, 12:33 pm, D from BC <myrealaddr... at (no spam) comic.com> wrote:
On Wed, 4 Nov 2009 09:10:48 -0800 (PST), "J.A. Legris"
jaleg... at (no spam) sympatico.ca> wrote:
IIRC you should apply for the patent before you release the product
(or even just keep it secret) or you may lose your rights. This
presumes patenting the thing is a good idea in the first place - which
is unlikely unless you have deep pockets.
http://en.wikipedia.org/wiki/Prior_art
It's not fair if I lose my patentability rights when I'd like to
release 200 units for ~field testing~
to tweek and finalize the design.
The wikipedia article mentions that you can protect your rights by
obtaining non-disclosure agreements.
We spray paint our PCB's black, for a sealant and thermodynamic
(black-body) radiation, it also makes a direct copy difficult.
Not sure why you think black paint increases thermal radiation, but
it's certainly not going to stop anyone from copying the design. It
may slow them down by about five minutes. Maybe.
[/quote]
It also makes the board likely to fail. The solvent in spray paint is
hard on parts. As a result the product will get a reputation for
being crap. Since nobody wants to make a copy of a crap product,
people will be less likely to copy it. |
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| krw... |
| Posted: Thu Nov 05, 2009 7:19 pm |
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Guest
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On Thu, 5 Nov 2009 15:08:58 -0800 (PST), "Ken S. Tucker"
<dynamics at (no spam) vianet.on.ca> wrote:
[quote]On Nov 4, 7:46 pm, "J.A. Legris" <jaleg... at (no spam) sympatico.ca> wrote:
On Nov 4, 12:33 pm, D from BC <myrealaddr... at (no spam) comic.com> wrote:
On Wed, 4 Nov 2009 09:10:48 -0800 (PST), "J.A. Legris"
jaleg... at (no spam) sympatico.ca> wrote:
IIRC you should apply for the patent before you release the product
(or even just keep it secret) or you may lose your rights. This
presumes patenting the thing is a good idea in the first place - which
is unlikely unless you have deep pockets.
http://en.wikipedia.org/wiki/Prior_art
It's not fair if I lose my patentability rights when I'd like to
release 200 units for ~field testing~
to tweek and finalize the design.
The wikipedia article mentions that you can protect your rights by
obtaining non-disclosure agreements.
We spray paint our PCB's black, for a sealant and thermodynamic
(black-body) radiation, it also makes a direct copy difficult.
[/quote]
Not sure why you think black paint increases thermal radiation, but
it's certainly not going to stop anyone from copying the design. It
may slow them down by about five minutes. Maybe. |
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| Ross Herbert... |
| Posted: Thu Nov 05, 2009 11:06 pm |
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Guest
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On Mon, 02 Nov 2009 13:16:28 -0800, D from BC <myrealaddress at (no spam) comic.com> wrote:
:I'd like to pot my smt pcb with the nastiest sh*t possible to make it
:hell for copy cats..
:
:So far I've found:
:
:http://www.mgchemicals.com/products/832ht.html
:'Extremely difficult to remove - grants incredible technology
:protection '
:
:Besides epoxy.. Are there alternatives?
:
:ex: Very very hot melt? Low melting point glass?
:
 from BC
:Amateur smps designer
:British Columbia, Canada
:Posted to sci.electronics.design
One thing you need to remember.. if there are any heat generating components on
the board, encapsulation in a hard compound may cause subsequent fracturing of
components or solder joints because they can't expand and contract. This may not
be such a problem with smt but it has caused problems with thru-hole components
on some pcb's I have repaired.
Since Araldite 2014 (3 types btw)
http://www.kirkside.com.au/Uploads/Images/2014.pdf is a bonding adhesive it may
cure to be extremely hard and may not allow expansion/contraction of components.
If this is likely to be a problem I would recommend a thin coating of pourable
white silicone rubber (or similar) over the heat generating components before
applying the Araldite 2014. |
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| Vladimir Vassilevsky... |
| Posted: Thu Nov 05, 2009 11:37 pm |
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Guest
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Ross Herbert wrote:
[quote]One thing you need to remember.. if there are any heat generating components on
the board, encapsulation in a hard compound may cause subsequent fracturing of
components or solder joints because they can't expand and contract.
[/quote]
I know an engineer who spent many years mixing different compounds and
fillers trying to create solid substance with minimal expansion or
contraction while it is cured, and which will not rip the components off
the PCB because of thermal effects. This is no simple problem.
Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com |
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| Ross Herbert... |
| Posted: Fri Nov 06, 2009 12:04 am |
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Guest
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On Thu, 05 Nov 2009 22:37:53 -0600, Vladimir Vassilevsky <nospam at (no spam) nowhere.com>
wrote:
:
:
:Ross Herbert wrote:
:
:
:> One thing you need to remember.. if there are any heat generating components
on
:> the board, encapsulation in a hard compound may cause subsequent fracturing
of
:> components or solder joints because they can't expand and contract.
:
:I know an engineer who spent many years mixing different compounds and
:fillers trying to create solid substance with minimal expansion or
:contraction while it is cured, and which will not rip the components off
:the PCB because of thermal effects. This is no simple problem.
:
:
:Vladimir Vassilevsky
:DSP and Mixed Signal Design Consultant
:http://www.abvolt.com
I entirely agree with you Vladimir... However, depending upon the amount of heat
generated or the degree of expansion/contraction involved it may not be as
extreme as your engineer friend encountered.
The very first instance of this type of problem which I encountered was in
electronic ignition systems from Johnson outboard motors back in the 70's. After
dissolving the epoxy encapsulant (that took weeks using an expensive chemical
solvent supposed to be specific to this purpose) it was discovered that several
soldered joints had failed and pcb pads had actually been lifted from the board
by the expansion of vertically mounted resistors in particular. Incidentally,
the solvent removed the coatings on resistors and other capacitors so
determining values was impossible in many case. I never intended to repair the
units but I was interested in the failure mechanism of these units. I
communicated my findings to Johnson at the time but I never received any
acknowledgement. |
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| D from BC... |
| Posted: Fri Nov 06, 2009 12:46 am |
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Guest
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On Thu, 5 Nov 2009 18:42:45 -0800 (PST), MooseFET <kensmith at (no spam) rahul.net>
wrote:
[quote]On Nov 5, 4:19 pm, krw <k... at (no spam) att.bizzzzzzzzzzz> wrote:
On Thu, 5 Nov 2009 15:08:58 -0800 (PST), "Ken S. Tucker"
dynam... at (no spam) vianet.on.ca> wrote:
On Nov 4, 7:46 pm, "J.A. Legris" <jaleg... at (no spam) sympatico.ca> wrote:
On Nov 4, 12:33 pm, D from BC <myrealaddr... at (no spam) comic.com> wrote:
On Wed, 4 Nov 2009 09:10:48 -0800 (PST), "J.A. Legris"
jaleg... at (no spam) sympatico.ca> wrote:
IIRC you should apply for the patent before you release the product
(or even just keep it secret) or you may lose your rights. This
presumes patenting the thing is a good idea in the first place - which
is unlikely unless you have deep pockets.
http://en.wikipedia.org/wiki/Prior_art
It's not fair if I lose my patentability rights when I'd like to
release 200 units for ~field testing~
to tweek and finalize the design.
The wikipedia article mentions that you can protect your rights by
obtaining non-disclosure agreements.
We spray paint our PCB's black, for a sealant and thermodynamic
(black-body) radiation, it also makes a direct copy difficult.
Not sure why you think black paint increases thermal radiation, but
it's certainly not going to stop anyone from copying the design. It
may slow them down by about five minutes. Maybe.
It also makes the board likely to fail. The solvent in spray paint is
hard on parts. As a result the product will get a reputation for
being crap. Since nobody wants to make a copy of a crap product,
people will be less likely to copy it.
[/quote]
Ha.. Copy protection by deliberate low quality. |
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