Epoxying over chip numbers?

[Robert Baer]

John Muchow wrote:

acetone

Isn't there a chance that the acetone could affect the bond between
the IC legs and the case material, i.e., some of the acetone could
work its way inside and cause damage? Or is the chance of that no
greater than the possibility of damaging the chip with our Dremel?

John Muchow
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Acetone has about the same effect as water; the dremel tool can do a
lot of damage if one wants...

 

[Robert Baer]

John Muchow wrote:

Abrasion does the trick: sanding, milling, laser.
However, anyone can still find out what chips you used, so why bother?
No other company i know of does something as infantile as hiding part
numbers.

Infantile...interesting choice of words. I'm finding out that this is
a surprisingly emotional topic for a lot of people. Frank has brought
up some great reasons for not hiding chip numbers, but there's still
the problem of micros, etc.

Because of the simple design of these products (it's the unique
packaging and combination of features that separates them from the
competition), we'd like to slow down anyone interested in copying the
design just a bit...until they come to market. Then, we can use
market penetration, great pricing, great tech support, etc. to make it
not profitable (we hope) for others to use our design.

It will inevitably happen, but if a few seconds of sanding (or
epoxying) of our prototypes can slow this process down until the
production models appear, that sounds like a damn good investment in
time and money to me.

How is hiding part numbers infantile? How is using a micro without
posting the source code not infantile then? I'm serious.

John Muchow
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Epoxy will be of no use.
Sanding, grinding or laser abrasion are the only effective ways of
"hiding" (removing) part numbers.
Use of FPGAs, PALs or micros is standard industry practice, and coding
is usually kept in house (also standard industry practice.
If you want to confuse the troops, add logic and linear that does no
useful purpose, but looks like that it is being used.
Also, put some critical traces under ICs with other traces that look
like they are needed both under ICs and visible, that do no useful
function.
Try added layers with used and extra traces; blind vias, etc.

Housesomeever, it all can be eventually decoded by someone with the
right tools and time...

I think that removing the legends off ICs will only pique someone's
interest, and therby hasten the eventual "decoding".

 

[Robert Baer]

Jim Thompson wrote:

On Sun, 04 Jul 2004 20:15:08 +0200, Brane2 <brane2@anonymous.com
wrote:

John Muchow wrote:

SNIP

How is hiding part numbers infantile? How is using a micro without
posting the source code not infantile then? I'm serious.


John Muchow
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Hiding part numbers is infantile because it is major pain in the ass for
anyone trying to service the device and because it doesn't stop anyone
trying to duplicate it.

It can buy you a few days at the most with the copycats and a frontrow
seat in hell, reserved by anyone who have tried to service your product
without full documentation and portfolio of spare parts...

With code inside micro, it's much different thing. It is still awkward
for servicing, but at least it is efficient against hobbyistic copiers,
so it achieves its basic goal- reasonable IP protection.

regards,


Branko

I'm astonished at the number of people on this group who are incapable
of reading.

The OP said "prototypes".

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

FPGAs, PALs and micros all have been used in prototypes...

 

[Sal Brisindi]

With this long discussion, we still don't know what it is...its like a
soap opera, Who killed JR?

Regards,
Sal Brisindi
http://www.numitron.com

John Muchow wrote:

OK, we've determined that anyone who covers chip numbers will burn in
hell, that sanding and electric erasers work great, that Dremels work
great (but be careful), but no one had any recommendations for an
epoxy?

Guess we'll have to keep using the Dremel for the rest of the
prototypes. Thanks for your suggestions and advice!!.

...hey, is it getting hot in here?

John Muchow
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[Keith Wootten]

In message <c9ohe0ph4of1bqmgr2ps0872vcus5pdlr4@4ax.com>, John Muchow
<jmuchow@SPAMMENOTcamlight.com> writes

OK, we've determined that anyone who covers chip numbers will burn in
hell, that sanding and electric erasers work great, that Dremels work
great (but be careful), but no one had any recommendations for an
epoxy?

<Snip>

If they're though-hole chips, fold the legs over and mount the chip on
the reverse side of the board (or re-lay the PCB). Or, instead of a
Dremel, use a sheet of emery paper flat on the desk and erase the
markings before soldering.

Cheers
--
Keith Wootten

 

[Julie]

John Muchow wrote:

We have several prototypes being built over the next few weeks and
wanted to hide the chip numbers of some of the glue logic. We've
sanded them off up to now, but that's an awful and time consuming way
to do it. A search of the sci.electronics groups came up
empty....amazingly.

Does anyone have any recommendations for covering up the numbers on
plastic and ceramic DIP packages? Loctite's black Prism 410 adhesive
looks good, but we're not sure if it will stick well enough or if it
can be pried off like a "pancake".

Or is sanding still the best option for doing this?

Thanks!

John Muchow
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How many protos are you talking about? 10s, 100s, more?

Can you just pot the entire board? Or do you need to have subsequent access to
it?

Several have mentioned laser etching -- I'm presuming that you don't have
immediate access to one of those, nor want to spend $25k for one at the
moment... You may be able to achieve this in a cost-effective way by visiting
your local sign/engraving shop. Most have (on-site) access to a laser engraver
which should perform adequately well in a situation as this. You could
probably get the cost down pretty low per piece as well.

 

[Mark (UK)]

Ha!

It's more like - what the hell WAS in the case in Ronin

Yours, Mark.

Sal Brisindi wrote:

With this long discussion, we still don't know what it is...its like a
soap opera, Who killed JR?

Regards,
Sal Brisindi
http://www.numitron.com

John Muchow wrote:


OK, we've determined that anyone who covers chip numbers will burn in
hell, that sanding and electric erasers work great, that Dremels work
great (but be careful), but no one had any recommendations for an
epoxy?

Guess we'll have to keep using the Dremel for the rest of the
prototypes. Thanks for your suggestions and advice!!.

...hey, is it getting hot in here?

John Muchow
-- remove SPAMMENOT for e-mail responses --

 

[Rich Grise]

on Sunday 04 July 2004 10:08 pm, John Muchow wrote:

OK, we've determined that anyone who covers chip numbers will burn in
hell, that sanding and electric erasers work great, that Dremels work
great (but be careful), but no one had any recommendations for an
epoxy?

Guess we'll have to keep using the Dremel for the rest of the
prototypes. Thanks for your suggestions and advice!!.

...hey, is it getting hot in here?

To use epoxy and make it stick, you'd have to sand the chips anyway.
But you can get a more aggressive wheel than an eraser! I work in a
weld shop, and they have little (air-operated) angle grinders, just
like a Dremel, but with a right angle at the business end, so you
can use a sanding disk, or whatever it's called.
--
Cheers!
Rich

 

[Rich Grise]

on Monday 05 July 2004 09:57 am, Mark (UK) wrote:

Ha!

It's more like - what the hell WAS in the case in Ronin

Was it really the girl's head in the box?

--
Cheers!
Rich

 

John Muchow <jmuchow@SPAMMENOTcamlight.com> wrote:

Guess we'll have to keep using the Dremel for the rest of the
prototypes. Thanks for your suggestions and advice!!.

How many prototypes are we talking about here anyway?

[And does camlight mean (video) camera light?]

--
William Smith
ComputerSmiths Consulting, Inc. www.compusmiths.com

 

[John Muchow]

I think that removing the legends off ICs will only pique someone's
interest, and therby hasten the eventual "decoding".

Good tips, thanks.
And you bring up a very good point about piquing someone's interest!

But, for the prototypes we're hoping that the short time each user has
them makes it improbable (famous last words) that they'll reverse
engineer everything.

John Muchow
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[John Muchow]

If they're though-hole chips, fold the legs over and mount the chip on
the reverse side of the board (or re-lay the PCB). Or, instead of a
Dremel, use a sheet of emery paper flat on the desk and erase the
markings before soldering.

Two great ideas I would have never thought of. We tried manual
sanding with the paper wrapped around various objects and the chips in
conductive foam...but it didn't work well at all.

Thanks!
John Muchow
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[John Muchow]

How many protos are you talking about? 10s, 100s, more?

Several lots of 5-10pcs. This will be a regular thing as new products
are developed so we're looking for good ideas for use now and in the
future.

Can you just pot the entire board? Or do you need to have subsequent access to
it?

Good idea but we need access to right-angle DIP switches from the
sides of the boards.

Several have mentioned laser etching -- I'm presuming that you don't have
immediate access to one of those, nor want to spend $25k for one at the
moment..

Ummm....not just yet.

You may be able to achieve this in a cost-effective way by visiting
your local sign/engraving shop. Most have (on-site) access to a laser engraver
which should perform adequately well in a situation as this. You could
probably get the cost down pretty low per piece as well.

Interesting idea and definitely worth considering if we were going to
remove numbers from the chips in the production runs.

Hmm, wait a sec.....we do have a couple of chips that are used in
every product. Might be worth lasering a couple hundred of each for
future prototypes.

Good idea, thanks!

John Muchow
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[Rich Grise]

on Wednesday 07 July 2004 12:36 am, John Muchow wrote:

How many protos are you talking about? 10s, 100s, more?

Several lots of 5-10pcs. This will be a regular thing as new products
are developed so we're looking for good ideas for use now and in the
future.

Can you just pot the entire board? Or do you need to have subsequent
access to it?

Good idea but we need access to right-angle DIP switches from the
sides of the boards.

Don't exactly pot the board, but conformal coat it really thick with
something tough and opaque. In either case, just mask off the switch.

I was gonna respond to another comment, about a safer method, by saying
"operator training." ;-)

Find out from your chip vendor what it costs to get house numbers
on, say, 1000 parts. You might save money, not to have to pay somebody
to sand chips. Just make up some random part numbering system, and
keep it a secret.
BZQX == 7400
#q87S == CD4060

etc.
(of scourse, you could make up house numbers that sound like
actual house numbers, like 04-101, 03-227, and so on. be careful
not to lose the cross-reference!)

Like when Peggy Hill said to the shoe guy, I'd like a pair of
women's size 16 bowling shoes, marked 8 1/2. He measures her foot,
and says, "No, you want a pair of women't size 16 _and a half_
bowling shoes, marked 8 1/2." I think she cried. ;-)

--
Cheers!
Rich