Comment by gruez 2 days ago
It's a solid piece of silicon encased in epoxy, so there's nothing really to get crushed. Contrast this to something like a cellphone that's made of hundreds of separate parts and has void space that will get crushed.
How would you do screen replacement? That is a common repair since people drop their phones and currently you can get your phone repaired by some teenager in a booth at the mall. If you fill the phone with epoxy, how are you detaching the screen, and getting a new ribbon cable through the epoxy?
So what if you can't replace a screen on an epoxy-filled cell phone? That's a small price to pay for knowing that your camera will survive if you take a one-way trip to crush-depth.
> Which means air space that can get crushed
Would note that air isn't the only substance in a phone that compresses under 38 MPa. (Batteries come to mind.)
Just like they do it today - a lot of grinding, swearing and overall understanding what the civilization is going in not quite the right direction.
Filling dive watches with oil (hydro modding) is pretty popular. It mainly helps with visibility but also increases the depth rating.
I'm sure there are some companies who want to do that, as long as they can convince people it's better for security or something.
When was the last time your phone stopped working due mechanical PCB damage?
Typically the limiting factor on your phone is the screen breaking, your battery life getting too short, wear and tear on components like buttons or the charging port, and factory defects. Epoxy isn't going to help with any of those. The only thing it would help with is exposure to water, but if other parts of your phone like your screen aren't water proof, what's the point?
Epoxy adds weight and manufacturing cost. It introduces design challenges as you need to balance the thermal expansion of the various parts. It's an extra step that can go wrong, and makes repair of other defects far more difficult. What benefit is there for the typical consumer that outweighs these costs?
To add to that. My son got his phone caught in a reclining chair without realizing it. The fact that the phone bent in half instead of destroying the chair is a nice bonus. Replacing the phone was cheap, replacing a chair would not have been — yes, both are insured, but replacing/repairing a chair takes a hell of a lot longer.
The heavy components on a cell phone PCB are reinforced with spot applications of adhesive to the PCB.
Filling the entire cell phone with epoxy wouldn’t help. The parts that break on drops are external like the screen.
This SD card was enclosed in a sealed metal container so it wasn’t exposed to water.
> Why isn't a cellphone filled with epoxy?
A conformal coating isn't "filled with epoxy", which is the concern I was answering.
I didn't notice that, I was dictating to Gboard. If that's what was heard, then I should probably go eat some hay and get my tail brushed.
Because then it gets a 0/10 repairability score on ifixit :)
That can be avoided by filling it with a fluid that the repairman can simply drain instead.
People hydromod digital quartz wristwatches by filling them with oil. This gives them truly absurd water resistances and even improves the readability of the screen somehow.
Imagine how much drama they could have avoided if they filled the entire submersible.
This comment made me wonder how much easier proximity fuzes would have been to develop in WW2 had they had transistors (or integrated circuits). I assume making modern solid state electronics 20,000g shock resistant is much easier than doing the same to vacuum tubes.
No need to wonder, proximity fuzes are still used today. And yes, they are much smaller, cheaper, more reliable, and precise.
Are consumer grade cards really reliable though? Not so much against physical damage, but of data integrity over extended periods? "Industrial" SD cards can be 10 times or 100 times more expensive than consumer grade cards.