iPhone 5 "most difficult device" to make

If the iPhone 5 is proving tough to find, that's likely because it's proven tough to make, as well. A Foxconn executive told the Wall Street Journal that Apple's latest smartphone has been difficult for the manufacturing company to produce

"The iPhone 5 is the most difficult device that Foxconn has ever assembled," the executive said. "To make it light and thin, the design is very complicated. It takes time to learn how to make this new device. Practice makes perfect. Our productivity has been improving day by day."

This is not the first time iPhone 5 manufacturing difficulties have come up. The phone's aluminum casing has proven susceptible to scratches, and tightened manufacturing standards sparked fights between factory workers and quality control inspectors. Those skirmishes were followed by a strike that briefly brought production to a halt earlier this month.