This work proposes the sub-module integration of flyback converters with an unique unfolding H-bridge inverter, for photovoltaic (PV) microinverter application. An dedicated control strategy is also proposed. This sub-module integration proposed to remove the existing junction box of the PV module and replace the three by-pass diodes with three individual DC-DC converters connected to a single-phase inverter, in order to decoupled the maximum power point (MPP) of three groups of cells or sub-modules. Particular attention is given to systems operating under long-term non-uniform conditions, such as dust or snow accumulation. The behavior of the proposed configuration are verified through simulation, and a comparison with a classical interleaved-flyback with unfolding H-bridge is provided to analyze the performances and quantify the improvements of the proposed structure under mismatching scenarios.