[MacBook Air Teardown] Battery Module Covers 2/3 of Bottom Surface [Part 2]

Feb 15, 2008
Nikkei Electronics Teardown Squad

We decided to "open" the MacBook Air right away.

Let's review its specifications. The most remarkable feature is its slimness. The thinnest part is only about 4mm, and the thickest part is approximately 19.4mm. The large gap in the thicknesses is attributed to the aluminum alloy plate, which is curved like a bowl and used as a bottom chassis. The thickness of the thickest part, 19.4mm, is "the slimmest of all the notebooks being produced and sold as of January 2008," according to Apple.

There were some notebooks that were thinner than the MacBook Air in the past. Sharp Corp's "Mebius MURAMASA," for example, was only 16.6mm thick. Nevertheless, the MacBook Air's "slimness" seems to go beyond the measure of 19.4mm. This is probably due to the curved body design as well as the chassis, which is as small as an A4-size laptop.

Its basic processing performance was not compromised. The microprocessor is Intel Corp's 1.6GHz "Intel Core 2 Duo," and the capacity of its main memory is 2 Gbytes. The lap top is equipped with a 13.3-inch LCD display with 1280 x 800 resolution and a full-size keyboard. And it is compatible with both IEEE802.11n standard WiFi and Bluetooth 2.1.

The alleged battery life is about five hours when the wireless LAN is active. The computer is, however, poorly equipped with interfaces other than the wireless capabilities. The MacBook Air has no optical disc drive, only one USB port and no wired LAN port.

The Teardown Squad started from observing the main substrate and the secondary battery module in the bottom of the chassis. We removed screws fixing the PC's bottom surface with a precision driver. The MacBook Air, whose secondary battery is replaced at a retail store, was apparently designed so that it can be easily taken apart by retailers. After removing the screws, we could open the bottom chassis very easily.

"Wow," we sighed. What appeared before us was a large secondary battery module. It was so big that it almost covered two-thirds of the entire bottom surface area. It was an Li polymer secondary battery. It wasn't marked with any company names other than Apple's. Its voltage was 7.2V, and the capacity was 37Wh.

The removed aluminum alloy plate is roughly 1mm thick. It appeared to be a pressed item because it did not have a lib structure to increase its strength. The structure of the aluminum plate's edge was designed to stand vertically, which seemed to increase its rigidity.

The 1.8-inch HDD beside the radiation fan was an 80-Gbyte product manufactured by Samsung Electronics Co Ltd of Korea. A 1.8-inch HDD costs more but requires smaller mounting area compared with a 2.5-inch HDD, which is generally used for notebook PCs. Therefore, it allows the secondary battery module to take more space.

After removing the heat radiation plate, we saw a chipset covered with thermal grease.

The chip on the right looks like "Intel Core 2 Duo." According to Intel, the chip package was tailored for the MacBook Air. The company reduces the mounting area of the chip by about 60% compared with the standard product.

Probably thanks to the reduction in the mounting area of this customized package, mounting density of the other components on the main substrate was not so high.

The chipset is covered with a black heat radiation plate. Probably, the heat generated by the chipset spreads across the radiation plate first and is released by the slim fan sitting on its right as exhaust heat. Also, the heat seemingly spreads to the aluminum alloy plate on the bottom of the chassis and the keyboard module via radiation sheets.