[jsheard]

It's hard to see but the original NAND is epoxied to the motherboard, which wouldn't come away easily with heat. I'm not sure what the purpose of the epoxy is but he goes to the trouble of replacing the epoxy later in the video so there must be a good reason for it.

[Retr0id]

The epoxy protects from physical shocks and also helps manage the effects of thermal expansion, either of which could crack solder joints over time.

[jsheard]

Ah, not taking any chances after bumpgate.

[Retr0id]

Apple has been epoxying BGAs at least as far back as the iPod nano 1st gen, released in 2005

[NavinF]

It's called "underfill" and it's common for BGAs since the chip doesn't have the same thermal expansion as the PCB

[matthewfcarlson]

I’ve seen some fascinating slo mo videos of devices bouncing from a decent fall in an X-ray machine. The battery in particular squishes way more than you think should be possible or right. Epoxy makes a ton of sense when you consider the shock that it takes.