Ha! 30 seconds after I posted my quick, not-much-of-a-hardware-guy iPad hardware first impressions, I got an email from the kind folks at iFixit – with lovely details of their iPad dissecting efforts.
Here’s some of what they discovered:
The iPad’s battery has 5.5x the capacity of the battery in the iPhone! The iPad actually has two batteries wired in parallel, for a total of 24.8 Watt-hours.
On average, the iPad sips just 2.5 Watts. That’s 1/5 the power of a compact fluorescent bulb!
The rear case is machined from a single billet of aluminum, increasing weight but greatly improving the rigidity of the device.
The empty void in the upper right corner is where the cellular communications board would go in the 3G iPad.
The A4 is a Package-on-Package (PoP), with at least three layers of circuitry layered on top of each other. A4 is packaged just like the iPhone processors, microprocessor in one package and two memory modules in the other package. They’re all sandwiched together in a very nice and thin PoP.
The iPad RAM is INSIDE the A4 processor package. Confirming this took quite a bit of sleuthing: we had to partner with Chipworks to X-ray the processor. The X-ray revealed two layers of RAM. In addition to the ARM processor, the A4 package contains two stacked Samsung dies.
The rumored slot for a camera is actually taken up by the ambient light sensor.
The glass panel is quite thick: about 1.18 mm, compared to the iPhone’s 1.02 mm thick glass. This is necessitated by the panel’s large size.
Lots more details and cool pics of the teardown process at the iFixit article on this: