Japan Short-Circuits the Tech Exports That Made South Korea Rich

Think of them as weapons of mass disruption. Three ingredients crucial to the global supply chain for smartphones and semiconductors are caught up in a diplomatic wrangle between Japan and South Korea whose origins date to long before either country had transformed itself into a consumer-­electronics powerhouse.

In July authorities in Tokyo began requiring Japanese businesses to apply for licenses to export fluorinated polyimide, hydrogen fluoride, and photoresist—a liquid used by semiconductor makers to imprint silicon wafers—to South Korean customers, a process that can take 90 days or more. The three chemicals are essential inputs in the manufacture of memory chips as well as TVs and other types of displays, which are pillars of South Korea’s $1.6 trillion export-driven economy. They are ­present in Apple iPhones, Dell laptops, and a broad range of Samsung devices.