Apple iPad 2 innards

The Teardown: Apple iPad 2

We pull apart Apple's second-generation tablet, and discover that it features a new apps processor and manufacturing innovations.

The second-generation iPad sees Apple trying to maintain its armlock on the emerging tablet computing market. The product incorporates a number of innovations, including a new apps processor and a lightweight mechanical construction. It now has front and back cameras that allow for video-conferencing, branded FaceTime.The version considered in the IHS iSuppli teardown is the 32GB WiFi and 3G edition. This retails at £579.00 in the UK and $729.00 (£442.46) in the US. The overall component count is 1,227 (excluding box contents), of which 652 components reside on the Main PCB and 227 on the 3G Module.  In comparison, the original iPad 3G had an overall component count of 1,618.

Introducing the A5

The dual-core apps processor, the A5, is based on ARM's Cortex A9 core. It will offer much faster graphics processing within the same battery life budget - about 10 hours - of the first generation tablet. The chip is mounted in a ball-grid array package with 1,360 pinouts, more than double the number for its A4 predecessor.

The move to dual core has also seen Apple upgrade the package-on-package DRAM memory to the DDR2 speed and 512MB density, from mobile DDR and 256MB. The company has also switched memory suppliers from Samsung to Elpida (although Samsung is still thought to be the manufacturer of the A5 and the package itself).

As with most Apple apps processor designs, there is a companion Dialog Semiconductor power management chip. In the Apple 3GS, it was the Dialog 'Amanda' part; the iPhone 4, Apple TV and original iPad had the 'Ashley' part; and for the iPad 2 and the A5, there is the newer, larger 'Allison' part.

There are, of course, many components within the iPad 2 that remain much the same as the previous generation tablet. The 9.7in IPS display appears unchanged, as do the capacitive touch circuitry and controls. On the cellular modem (HSPA) side, many of the components are nearly identical to the 3G module found in the original version of the iPad 3G.

Compared to the original version iPad 3G at the 32GB configuration, the materials-only bill of materials of the new iPad comes in at just under $6 more than the original iPad. This data point hints at the very common strategy by Apple to manufacture devices within a specified cost budget that changes little year to year and from one product generation to another.

Design notes

"The new iPad is Apple's first tablet to use its pioneering all-aluminum unibody construction," says Wayne Lam, principal analyst for IHS iSuppli.

"In the same way that Apple ushered in a new technique in laptops starting with the 2008 MacBook Pro, they have [created] a thin unibody chassis that not only serves as the primary load-bearing substrate for the tablet but also as the mechanical foundation for all other components."

This has been critical to achieving a radical improvement in thickness over the first tablet. Another major factor is a revamp of the battery design, from a two-cell to a three-cell structure.

Apple is most likely the only manufacturer consistently wiring its battery cells in parallel to produce a large capacity battery package at the nominal 3.7V. The new iPad employs three extremely thin Li-Ion Polymer cells that appear to havee ben manufactured using Polymer Gel Formation (PGF) techniques. PGF improves both cell rigidity and density.

The resulting 6930mAh battery pack is in fact a 330mAh improvement over the previous, thicker, dual cell implementation found in the original iPad and still yields a purported 10-hours of continuous operations.

Also worth noting is the fact that the touchscreen glass seems to have been upgraded to a new hardened version, allowing Apple to apply a thinner overlay and use the glass panel as part of the structural reinforcement for the device.

Then there is also the return of the 'mysterious' capacitive touch sensor. "We previously postulated that a simple capacitive touch sensor in the back plastic antenna cover of the original iPad 3G was actually a user-sensing device intended to mitigate 3G cellular antenna attenuation due to blockage from users' thumb or other digits," says Lam. "Here, our theory is again tested and still stands. The second generation iPad again uses a capacitive sensor on a separate PCB that attaches to a capacitive touch pad that is located directly on the backside of the antenna housing to the cellular antenna."

Recent articles

Info Message

Our sites use cookies to support some functionality, and to collect anonymous user data.

Learn more about IET cookies and how to control them