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Laser-ing the IC markings off on a budget.

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KE5FX:

--- Quote from: beanflying on March 24, 2021, 06:54:56 pm ---How about keeping somewhere NEAR on the OP's topic? 

--- End quote ---

I think it's on topic. The OP is asking for ways to make it harder not only to copy a device, but to repair it.  Once the decision has been made to intentionally make it hard to repair a product, it's reasonable to suspect the manufacturer of intentionally limiting its service life in other ways.

My thinking has always been that no manufacturer would implement a "lifetime counter" because the risk -- meaning the product of the probability of being caught and the consequences that are likely to ensue -- would be horrific.  Then Dieselgate came along.   :palm:   So much for my thinking.

In general, though, I still believe that Hanlon's Razor applies more often than not.  Seagate's firmware problem was probably just a matter of using a 32-bit timestamp counter someplace where 64 bits would have been better.   Rest assured, they didn't make money selling drives that fail early, because people who buy lots of hard drives tend to keep track of such things. 

Likewise, the reason why cars last 100,000 miles before becoming uneconomical to own is simply because few people want to pay for new cars that last 200,000 miles before becoming uneconomical to own.  Porsche says that 70% of the cars they've ever built are still on the road... but in a world where every car has to meet that standard, billions of people are going to have to do without any cars at all.  Whether that's better or worse for humanity is definitely off topic, but the point is irrefutable.

At the end of all of this bloviation lies a simple question of engineering ethics.  If someone asks for advice on how to make their product worse, they will need to get it from someone besides me.  I buy lots of stuff myself, and I don't want it to to be more expensive, harder to repair, or for that matter, harder to understand.


--- Quote from: Simon on March 24, 2021, 07:29:55 pm ---You mean the guy who called everyone who would not give him the answer he wanted a troll and has not come back for a page and a half.

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The funny thing is that he was actually calling me a troll.  I dislike how EEVblog gives us like 15 seconds to correct a mistake or clarify a point before appending Last edited on $DATE by $NAME, who is either trying to hide something or needed to think his half-baked post through a little further.  So I usually just delete my post when I need to edit it, and then resubmit it as a new one.  Occasionally this breaks causality.  The lesson for the OP is to use the Quote button when setting out to call people trolls, lest he troll himself.   8)

ajb:

--- Quote from: beanflying on March 24, 2021, 06:34:16 am ---Pulsed notionally higher powered fiber lasers or CO2 (pulsed or not) won't make much difference as the power needed to ablate the surface will be a constant.
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It's not quite that simple.  Ablation is a thermal process, and the energy input to the top layer of material via the laser is working against the thermal conductance of the object which tends to carry away thermal power into the rest of the material.  So in order to get enough energy into the top layer of the material that you want to ablate before that energy diffuses into and thereby heats the bulk material you need to deliver that energy relatively quickly--thus a relatively high peak power is more effective.  Or more accurately, a high peak power density is required, since the ablation energy is a function of the area to be ablated.  So a cheap CW diode laser engraver could certainly cause greater heating and thermal stress or possibly chemical degradation to the part before adequately ablating the surface, both because it will have a worse beam profile and hence less effective focusing than fiber or CO2, and because it will have lower peak power versus a pulsed laser.  (And of course the wavelength is a factor too.)  Whether it's enough to make a real difference in process reliability in practice is a harder question to answer, and will depend on just how cheap and crappy of a diode laser engraver we're talking about.  Some real-world testing from which you can estimate the total energy applied to the part to get good results with either method is probably the best way to start figuring that out.

Microdoser:

--- Quote from: coppercone2 on March 24, 2021, 06:38:34 pm ---
--- Quote from: Microdoser on March 24, 2021, 01:20:53 pm ---
--- Quote from: Simon on March 24, 2021, 12:41:56 pm ---The important thing is to design for longevity and change the attitudes about constantly buying a new one.

--- End quote ---

I'm currently designing a product, and I am designing it to be easily repairable. I want the end user to keep using my product and repair it, extending the time they use my product well beyond the standard product lifetime. Every time a user needs to buy a new product is a chance they won't choose yours.

Furthermore, I will offer a repair and refurbish service at a fair price and I hope this, as well as consumable parts, will become a steady income stream. Repairs will, at the preference of the end user, be simple board switching or component level repairs to minimize repair cost. It should always be cheaper and easier to repair the product than buy a new one IMO.

I am fully aware that any vested interests will reverse engineer any product. My defence against that will be to offer superior customer service and a trustworthy brand identity.

--- End quote ---

And how about getting a good reputation while you are at it? People will keep buying the newer versions for many different reasons with confidence

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A good reputation is part and parcel of a trustworthy brand identity IMO and of course there will be newer versions which I hope previous customers will want to purchase based on their experience with the device and the company.

What I am not going to do is force them to buy a new version because they cannot repair their old version or make the repair price so high they may as well buy a new product.

SilverSolder:

--- Quote from: KE5FX on March 24, 2021, 07:50:06 pm ---[...] Porsche says that 70% of the cars they've ever built are still on the road... but in a world where every car has to meet that standard, billions of people are going to have to do without any cars at all.  [...]

--- End quote ---

Porsches probably get taken care of, and fixed, almost no matter what condition!  -  e.g. compared to an old Toyota taxi...

james_s:

--- Quote from: SilverSolder on March 24, 2021, 03:31:43 pm ---There are those who claim that planned obsolescence isn't a "thing".  -  It is definitely a "thing"...  in fact, every product ever (competently) designed has had a specific defined design life...   if you buy a car, everything is designed for 100K miles or 10 years...   if you buy a cell phone where the battery can't be changed, you know you are buying a product with a 2-3 year design life...   and so on.

--- End quote ---

Yes and no. In a sense it's true, but in my experience it's not a case of "we want this to fail after x number of years" but "we want this to last a minimum of x number of years, and build it as cheaply as possible." The goal is to make it cheap to build, not to make it fail, but a consequence of being cheap is that it often will not last as long.

One potential exception I can think of, back in the late 60s Westinghouse and GE each developed a formulation for the coating on mercury vapor lamp cathodes that created a translucent white deposit on the arc tube walls rather than the dark silvery black deposit of evaporated tungsten that was typical and they marketed these as their Westinghouse "Lifeguard" and GE "Bonus Line" lamps. They lasted longer, a LOT longer, I have seen some that were still going after 30 years of dusk till dawn service. After about 15 years both companies went back to the older cathode formulation and lifespan reduced to 3-5 years or so before they started getting really dim. It's possible though that even that came down to cost, and the fact that it coincides with around the everyone started pushing high pressure sodium lamps.

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