This is the second article that detailed the internal structure of the "iPhone 3G." Based on the first story, in which we torn down the iPhone 3G, we compared it with the previous model, iPhone 2G. We found Apple's measures to enhance the workability and reduce the mounting area and cost in various areas.

The "iPhone 3G," a third-generation (3G) mobile phone of Apple Inc, was released July 11, 2008, in 22 countries. Nikkei Electronics broke down an iPhone 3G released in Japan with the help of engineers from a Japanese parts manufacturer. We compared its components with those of the iPhone 2G, which was released in the US June 29, 2007, for analysis.

The appearance of the iPhone 3G is almost identical to that of the 2G model. However, its inside, including the parts layout, is totally different. We could see that assembly workability was improved and some measures were taken to reduce the mounting area as well as parts costs.

On the other hand, the electrical circuit seems to have been designed in line with the previous model, judging from the fact that most of the parts mounted on the main board are supplied by the manufacturers of the 2G model parts.

Parts laid out with considerations for workability

The outside dimensions of the handsets are almost the same, 115.5 x 62.1 x 12.3mm for the iPhone 3G and 115 x 61 x 11.6mm for the 2G model. In respect to functionality, the differences are limited to some mobile phone functions such as W-CDMA/HSDPA and GPS reception functions.

However, when we disassembled the two models, we saw big differences in terms of internal layout (Fig 1). The iPhone 2G had its main parts laid out on both sides of a metal frame in the central area of the chassis. The main board and the connector for external connection are positioned far from each other, and a flexible substrate for connecting them was wound inside the chassis.

In contrast, the parts were simply accumulated on the chassis cover in the iPhone 3G. It has one main board and the flexible substrate for connecting other modules is short. It is clear that the assembly workability was enhanced.

The rational design of the iPhone 3G. The iPhone 3G and the iPhone 2G are similar in appearance, but they are different in internal parts layout. The iPhone 2G had main parts mounted on both sides of a frame in the center of the chassis, while the iPhone 3G has the parts piled on the back cover of the chassis. In addition, the back cover of the iPhone 3G chassis is made of resin, allowing a more flexible layout of the antennas and making it possible to include a main antenna for W-CDMA and GSM and a sub-antenna for wireless LAN, Bluetooth and GPS at different locations. In the iPhone 2G, which had a metallic back cover, antennas were concentrated on the bottom of the chassis. In respect to the Li-polymer secondary batteries, both of the models are equipped with battery cells simply wrapped in a laminated film. Though there was no description about the battery capacities, but the volumes of the two batteries are almost the same. (Click to enlarge)
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