The iPhone 4's interior is surprising!

It has been three and a half years since the first iPhone was released. The fourth generation of the iPhone series, which has sold more than 50 million units worldwide, is the iPhone 4 from Apple Inc., an American company. Although it is not as novel as the original model, when you take it apart, you will find that its design is completely different from the previous one.


The iPhone 4, which was launched on June 24, 2010, was described as "the most successful product in Apple's history" by the company's CEO Steve Jobs. Within three days of its launch, 1.7 million units were sold worldwide. The iPhone 4 uses the new iOS 4 system, which not only supports multi-tasking, but also comes with features such as the e-book application "iBooks" and video calling, making it easier to use than previous generations. On

the other hand, the iPhone series has also entered a mature period. When the iPhone 4 was released, Steve Jobs emphasized hardware performance indicators such as the 9.3mm thin body and the display resolution of 326ppi (Table 1). "It's not Apple's style to emphasize performance indicators," many Japanese engineers thought.


However, what awaited the Nikkei Electronics disassembly team was a sudden change in the design of the Japanese iPhone 4 (32GB model) that we purchased from SoftBank. The disassembly investigation conducted with the assistance of engineers in various specialized fields allowed us to see a much more sophisticated internal design than before.

The background was the thinness and cost reduction

, "very much like a terminal developed by a Japanese manufacturer." The engineers who observed the disassembled body said in unison (Figure 1) that because there were traces of careful coordination with the component manufacturers, it was confirmed that efforts were made to improve the yield rate. Everywhere you look, you can see the sophistication that is very different from the previous "rough" design.

Figure 1 Whether in terms of weight or cost, LCD panels rank first . Photos, weights, and costs of iPhone 4 components are shown in the figure. The weight data comes from the survey results of Nikkei Electronics, while the cost data comes from the survey of iSuppli. (Click to enlarge)

The design has changed drastically, and it is believed that it is for the purpose of thinning and reducing costs. For example, the motherboard is equipped with a wireless LAN/Bluetooth module of a special shape (Figure 2), which "has never been seen before" (a mobile phone design engineer). He said, "Because of the need for thinness, the installation area is limited. It can be seen that Apple has carefully formulated the size and specifications of each functional block in advance, and has conducted detailed consultations and adjustments with component manufacturers." The same is true for the camera module: a flexible circuit board with a very special shape is used, and it is installed after being folded in a complex manner.

Figure 2 The strange-shaped module is surprising The WLAN/Bluetooth module installed on the motherboard. Due to its strange shape, it is believed to be a custom design. (Click to enlarge)

The lithium polymer rechargeable battery can be seen as a design that reflects the intention of cost reduction. In previous models such as the "iPhone 3G", the rechargeable battery was attached to the casing with strong double-sided tape. However, this time, the battery is connected to the motherboard with a connector, and a resin substrate is also installed to facilitate the removal of the battery (Figure 3). (To be continued by reporter Takuya Otani)

Figure 3 Lithium polymer rechargeable batteries are designed to be replaceable. The lithium polymer rechargeable battery of iPhone 4 has a removable sheet and is replaceable. The battery of iPhone 3G is fixed to the back cover with double-sided tape. (Click to enlarge)