
Edit Step 10
— Inside Chipworks
¶
Chipworks is based in Ottawa, Ontario. It gets so cold there that your tires can actually crack if you're not careful.
The equipment at Chipworks is quite different than you'll find in most semiconductor facilities. Every single machine they have exists with one purpose in mind: discovering what's inside the latest chips.

Edit Step 13 ¶
Grinding down a package. Keeping the part level as you grind is critically important.
This process is incredibly painstaking. There's actually a fine art in grinding to exactly the right spot for the photo while keeping the surface perfectly level.
We (at iFixit) are terrible at this. That's why we shipped our iPad to Chipworks.

Edit Step 14 ¶
The next step is to remove the outer packaging.
Tea time? Nope, just time for a nice acid bath.
Dipping the processor in acid dissolves the ceramic packaging containing the silicon. Using the appropriate concentration of acid for the type of ceramic packaging is critical.
Every once in a while, looking at a die yields nifty surprise hidden by the manufacturers. Alas, Milhouse was not found in the iPad. But he was recently discovered inside a Silicon Image chip!

Edit Step 15
— Inside the A4
¶
Alright, now you know how we did it. But what does the A4 look like inside?
Photos of the top and bottom of the A4 package.
Those tiny dots you see on the underside are solder balls that adhere the processor to the logic board. They transmit all power, grounding, and information to-and-from the processor and board.

Edit Step 16 ¶
Before dismantling it, Chipworks took an X-ray image of the A4 processor to get a feel for how things are laid out inside.
If you look closely, you can see hundreds of thread-like interconnects (wirebonds) that carry electronic signals between dies.
The A4 has three layers: Two layers of RAM (Samsung K4X1G323PE), and one layer containing the actual microprocessor.
This Package-on-Package construction gives Apple the flexibility to source the RAM from any manufacturer they want—they're not locked into Samsung.
Page 2 of 5