[iPad 2 Teardown (4)] Acceleration Sensor, Gyroscope Found in Unexpected Area

Apr 18, 2011
Nikkei Electronics Teardown Squad
The board mounted with the back-side camera module (right) and the cable that connects it with the main board (left). The camera module is located at the upper end of the board. The cable is a thin wire coaxial cable equipped with a connector that has a lock mechanism.
The board mounted with the back-side camera module (right) and the cable that connects it with the main board (left). The camera module is located at the upper end of the board. The cable is a thin wire coaxial cable equipped with a connector that has a lock mechanism.
[Click to enlarge image]
The two chips located at the lower end of the board mounted with the back-side camera module. The upper and lower chips seem to be a three-axis gyroscope and a three-axis acceleration sensor, respectively.
The two chips located at the lower end of the board mounted with the back-side camera module. The upper and lower chips seem to be a three-axis gyroscope and a three-axis acceleration sensor, respectively.
[Click to enlarge image]

Continued from [iPad 2 Teardown (3)] Heavy Use of Double-sided Tapes

There was another mysterious point about the internal structure of the iPad 2 in addition to its bilateral asymmetry.

It was the fact that the board mounted with the back-side camera module was located far from the main board and that they were connected by using a cable running across the inside of the chassis. Japanese makers would place the camera near the main board to make the cable as short as possible.

Probably, Apple considered it important to realize a good design and to have the back-side camera on the right side when a picture is taken by the camera.

As a cable, the company used a thin wire coaxial cable that seemed costly rather than a normal flat cable. An engineer considered that the thin wire coaxial cable was employed to reduce the influence of noise on the camera because the iPad 2 uses a longer cable.

There was another mysterious point about the board mounted with the back-side camera module in addition to its distance from the main board. In fact, we found an acceleration sensor and a gyroscope, which were not found on the main board, at the lower end of the board mounted with the back-side camera module.

There is no problem in placing an acceleration sensor in such an unusual area. However, a gyroscope is normally placed near the center of a machine because it detects the rotation of the chassis. Probably, Apple used software to correct the numerical value measured by the gyroscope placed at the lower end of the board.

We could not figure out the reason why Apple employed such a structure, but it could be the company's enthusiasm for slimness. The central area of the chassis is occupied by the lithium polymer rechargeable battery. Therefore, if the gyroscope is placed in the area, the thickness of the iPad 2 will increase. But why didn't the company place the gyroscope on the main board?

Through the teardown of the iPad 2, we noticed that Apple's design philosophy is clearly different from that of Japanese makers. It seemed that the priority orders of various features and functions were determined based on the company's aesthetic sense, and it designed the iPad 2 while giving first priority to realizing them. The iPad 2 made us wonder if products developed based on the philosophy of prioritizing costs and specifications can compete with it.