In order to further increase the power density of the integrated boost resonant (IBR) converter, a novel passive integrated unit is proposed by combining three inductors, two capacitors and one transformer. For saving the these passive components, the Flexible Multi-Layer Foil (FMLF) integration technique is used.To avoid the coupling of two boost inductors and the transformer, the symmetry structure is used in the proposed unit. The electromagnetic analysis of the proposed unit is given, and the calculations of the circuit parameters are provided. Finally, a prototype for a 350-W IBR converter has been built to validate the feasibility of the proposed integrated unit.