India, Sept. 26 -- India's semiconductor story has an obvious attraction: build more chips at home. But that simple idea hides a much harder engineering and business problem.

A chip does not become useful because its design is complete. It does not become commercially ready when the first silicon comes back from the fabrication plant either. Between a successful design and a chip running reliably inside an industrial system, vehicle, display, or other electronic product sits a long chain of work that gets far less attention.

The silicon has to be brought up and characterized. Problems have to be found and fixed. Manufacturing yields need to improve. Packaging has to protect the device without hurting its performance. Production tests ne...