One thing that I’ve always liked about flex circuits is that they look cool! Shiny, orange, and clear you can see those beautifully curved copper traces, unlike their green rigid-board counterparts.

But if you’ve looked inside a smartphone or seen a teardown article on an iPhone you don’t see beautiful shiny flex circuits – you see flex circuits that look like they were spray-painted with black primer.

Do not be deceived by their drab appearance – these are Ninja flex circuits! They have special coverfilms that give them powers to suppress EMI, eliminate glare, control impedance, and reduce cost. They also, disguise and protect intellectual property – it takes a great deal of effort to reverse engineer them and you literally destroy the circuit in the process.