The IPC-6013D covers qualification and performance requirements for flexible printed boards designed to IPC-2221 and IPC-2223. The flexible printed board may be single-sided, double-sided, multilayer or rigid-flex multilayer. All of these constructions may include stiffeners, PTHs, microvias, and blind/buried vias. IPC-6013D incorporates new and updated requirements for final finishes, rigid-to-flex transition zones, deformation anomalies including wrinkles, creases and soda strawing, marking, registration (annular ring), conductor thickness reductions, dielectric removal in holes, resin smear, copper filled microvias and selective (button) hole plating.