Nikkei Electronics Asia -- October 2008
Features
Opening Up eMobile's Lowest-Cost Mobile Phone

The most notable feature of the H11HW, released by eMobile Ltd of Japan in June 2008, is the price: for a two-year contract, the initial cost is only Yen5,980 (about US$55). And even without the two-year term in the contract the cost is only Yen29,980, or roughly half the price of handsets from competing communication carriers. 

The H11HW was developed by Huawei Technologies Co Ltd of China from the U550 handset designed for Europe. The functions are somewhat limited, and include voice, videophone, and high-speed datacom implemented via High-Speed Downlink Packet Access (HSDPA), as shown in Table 1. The low price is thought to have been achieved by dropping functions commonly found in Japanese handsets, such as one-segment television broadcast reception and FeliCa. We wanted to have a look inside, though, and with the cooperation of engineers from domestic manufacturers took the H11HW apart to get a glimpse of Huawei Technologies' design approach, which successfully combines low cost with high quality.

Inexpensive Components

First is the main board (Fig 1), which is fairly small: only about 46.0 x 40.5mm, and about 1.0mm thick. An engineer from a parts manufacturer commented, "That's thicker than a domestic manufacturer would use in a handset. In spite of the pared-down functionality, both sides of the board are tightly packed with components. It's a lot more compact that I expected." 

The MSM6260 mobile telephony chipset from Qualcomm Inc of the US is mounted on the main board. In the firm's wideband code division multiple access (W-CDMA) handsets, this same chipset is used in the low-end model. In addition, many of the peripheral components on the board are not the 0603 size (0.6 x 0.3mm) components used in domestic handsets, but larger 1005 sizes (1.0 x 0.5mm). The same engineer said that Huawei would most likely have selected inexpensive components to drop the total cost.

The main board housed another component almost certainly chosen for cost reasons: the Universal Serial Bus (USB) connector manufactured by Astron Technology Corp of Taiwan. The connector is also used to connect the charger and the headphones. The components engineer explained, "Using a single connector for multiple external inputs is pretty common in Chinese handsets. European, Japanese and other manufacturers don't do it because it means you can't listen to music while charging, but it is a good way to drop the cost."

Cost reduction measures can be seen on the display side as well. The connection to the sub-display, an organic light-emitting diode (OLED) panel, is a direct solder to the board rather than via a flexible printed circuit (FPC) board (Fig 2). Again, "This type of connection is common among Chinese manufacturers. The technique is effective in China because of the low cost of labor." The speakers, vibration motor and other components, soldered in the same manner, are about double the size of similar components used by domestic manufacturers, which again suggests that cost influenced these choices. 

The engineer also closely inspected the camera module, which is an integrated system with an outside camera of about 2 megapixels and an inside camera of about 300,000 pixels. "This is the first time I've ever seen a camera module like this. You can't use both cameras at once, but they've really done a good job at slashing the number of connectors!"

Best Parts Where Needed

While there are many signs of cost-conscious construction, designers didn't fret about the cost where product features, quality, etc, demanded the best. For example, connectors on the main board, display, camera module, etc, are, according to an engineer at a components manufacturer, "the very latest parts from Japanese manufacturers. It looks like they assigned a high priority to connections in voice, display and other points that strongly affect quality."

Touch sensors are also provided on the back of the display for music player control. Manufactured by Synaptics Inc of the US, they appear to use capacitive sensing. Resistive membrane designs would unquestionably be less expensive, but apparently designers felt the higher price was justified because they are crucial in determining ease of use.

by Shinya Saeki

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