Circuit board and manufacturing method thereof

A circuit board, comprising at least one bending area and at least one non-bending area, wherein the at least one bending area abuts the at least one non-bending area, and the circuit board comprising:

• a first multilayered structure, comprising:
• a first flexible material layer;
• and
• a first cover film disposed on the first flexible material layer;
• a second multilayered structure, comprising:
• a second flexible material layer;
• and
• a second cover film disposed on the second flexible material layer;
• a third multilayered structure, comprising:
• a third flexible material layer;
• and
• a third cover film disposed on the third flexible material layer;
• a first adhesive layer disposed between the first multilayered structure and the second multilayered structure, and adhered to the first flexible material layer and the second cover film, wherein the first flexible material layer, the first adhesive layer and the second cover film are arranged between the first cover film and the second flexible material layer;
• a second adhesive layer disposed between the second multilayered structure and the third multilayered structure, and adhered to the second flexible material layer and the third flexible material layer, wherein the second multilayered structure is arranged between the first adhesive layer and the second adhesive layer, and the second flexible material layer, the second adhesive layer and the third flexible material layer are arranged between the second cover film and the third cover film;
• wherein a first compartment is formed between the first multilayered structure and the second multilayered structure, and a second compartment is formed between the second multilayered structure and the third multilayered structure;
• and
• a plurality of hollow portions formed on at least one of the first multilayered structure, the second multilayered structure and the third multilayered structure, wherein the plurality of hollow portions, the first compartment and the second compartment are arranged in the at least one bending area, and the plurality of hollow portions are communicated with at least one of the first compartment and the second compartment;
• when the at least one bending area is bent, a force is applied on the plurality of hollow portions to make the plurality of hollow portions deform and change a cross-sectional area of each of the plurality of hollow portions.