Virtually zero z space
"This is about the thinnest product I have done, so I spend a lot of my time getting component vendors to focus on physical packaging," said Canova.
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Indeed the thinness drove a range of design challenges for the device which is about the width and length of a standard sheet of paper.
"We have lots of x and y space but virtually zero z space," said Canova. "We aimed to make it as thin as a piece of paper, so we ruled out a lot of component that were too thick," he said.
For example, the startup could not use the kind of PCI Express modules for its combo Bluetooth/Wi-Fi subsystem common in notebooks. "They are thicker than our entire product," Canova said.
It also required a custom lithium polymer battery with several rectangular cells laid out side-by-side, connected by flexible circuit boards. In addition, it needed a unique power supply design to keep inductors and magnetic parts as thin as possible.
The resulting design sports more than a week of battery life, thanks in part to the display that requires no power to maintain an image. "I tell my engineers I want a device that is almost never on besides its real-time clock and some limited standby electronics," he said.
The device uses a tape carrier package to link its organic plastic display to its mainboard. It places its display driver circuits on a flex board.
The resulting complex yet thin "sandwich" of display, mainboard, wireless module, flex circuits and battery cells created problems for the startup's contract manufacturer in China. If a worker got one element out of alignment or used tape to hold down a component during a re-work process "it could create an interference defect or be outside the thinness limit," he said.
Coordinating a globally dispersed design team was also a challenge, albeit a typical one for Canova and others like him. The startup does final assembly in China, electronics design in Silicon Valley, display design in England and display manufacturing in its own plant in Dresden.
"We have engineers in virtually every major time zone, so we make heavy use of video conferencing," Canova said.
Heavy use of Skype audio, video and instant messaging tools is a fact of life. As in other jobs, Canova hired Chinese-speaking engineers to help work with the China contract manufacturer and secured a budget for frequent trips to visit the plant which is now ramping up production of the Que reader.
Good communications were also vital for keeping the engineering team focused on the product concept during the two-year re-design. Unlike some e-readers it aims to replace paper not books or notebook computers. Thus designers had to resist a desire to add Web browsing and e-mail capabilities, features many e-books sport.