To provide a components joining method and a components joining structure which can realize joining of components while securing conduction at a low electrical resistance with high reliability.In a construction in which by using a solder paste containing solder particles 5 in a thermosetting resin 3a, a rigid substrate 1 and a flexible substrate 7 are bonded by the thermosetting resin 3a, and a first terminal 2 and a second terminal 8 are electrically connected by the solder particles 5, a blending ratio of an activator of the thermosetting resin 3a in the solder paste is properly set and oxide film removed portions 2b, 8b, and 5b are partially formed in oxide films 2a, 8a, and 5a of the first terminal 2, the second terminal 8, and the solder particles 5. Thereby, the first terminal 2 and the second terminal 8 are electrically conducted by solder bonding the solder particles 5 to both the first terminal 2 and the second terminal 8 via the oxide film removed portions 2b and 8b, and while fusion of the solder particles 5 with each other is prevented in the thermosetting resin 3a, connection of components at a low electrical resistance is realized with high reliability.