[MacBook Air Teardown] Elaborate Body Structure Hints High Cost [Part 10]

Aug 15, 2008
Atsushi Ooshima
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Characteristics of the body structure

As shown in the previous figure, the top plate of the body is the main chassis on which the keyboard, main board, HDD, Li-polymer secondary battery, etc are fixed. The top board is apparently an aluminum alloy casting processed by milling and very costly because there are a considerable number of processed portions.

The rigidity of the top plate is low because it is thin and has many apertural areas. However, when a shallowly curved bottom plate is attached to the top plate with 10 screws, the top plate becomes drastically strong against being bent and twisted.

It is likely that the top and bottom plates are slightly curved at the point of production. Probably, the rigidity of those plates increase because they will become flat in a state of tension after being fixed by screws.

The back board of the display part is a 0.8mm-thick pressed aluminum sheet around which a magnesium-alloy frame is attached for reinforcement.

The latch mechanism of the display is not a hook type, which is commonly used, but it uses the absorption power of a magnet embedded in the frame of the display part. Of course, the mechanism cannot be seen from outside, so it is very smart.

On the back of the top plate, a piece of iron is attached to the part that overlaps the magnet. Also, the approach of the magnet is sensed by a hall element to judge if the notebook is open or closed.

There were some surprising findings in the parts of the disassembled MacBook Air. A small metal stay used for fixing an HDD is screwed on the back of the keyboard. And we found 0.8mm diameter small holes all over the stay. Considering the stay weighs only 1.2g, those holes reduces its weight by less than 1g. They must be the holes bored by the whim of the designers.

On the upper part of the LCD panel, there are holes for an illuminance sensor, microphone and camera. And the size of the many holes for the sensor and microphone is 0.025mm in diameter. It seems difficult to make those holes by press working. Were they drilled?

When we were modeling the MacBook Air by using a 3D modeling software, we felt Apple's strong will to make the most beautiful notebook Mac regardless of the cost as well as its outstanding sense of design.

NOTE: This article is a translation of an article published in the summer 2008 issue of Nikkei Board Guide. The numbers and part names in the text were estimated by the staff of the magazine.