The invention discloses a circuit board assembly. The circuit board assembly comprises a touch switch, a hot melting rubber ring and a circuit board, wherein the touch switch comprises a first pin anda second pin, the hot melting rubber ring is arranged on the touch switch, the first pin and the second pin are arranged in a region encircled by the hot melting rubber ring, a first connection groove and a second connection groove are formed in the circuit board, the first connection groove is opposite to the first pin, the second connection groove is opposite to the second pin, a surface, facing the circuit board, of the touch switch and a panel of the circuit board are pasted and fixed by the hot melting rubber ring, an external connection end of the first pin props against a bottom wall of the first connection groove and is electrically connected with a bottom wall of the first connection groove, and an external connection end of the second pin props against a bottom wall of the second connection groove and is electrically connected with the bottom wall of the second connection groove. With the circuit board assembly disclosed by the scheme, the problems of relatively high construction cost of the touch switch arranged on the circuit board by a surface-mounting process and relatively large width of the formed circuit board assembly can be solved. The invention also discloses amobile terminal and a fabrication method of the circuit board assembly.