Method of manufacturing circuit board

A method for manufacturing a circuit board, comprising:

• providing a single-sided board comprising a first insulating base, a copper layer covering a surface of the first insulating base, at least one first through hole each passing through the first insulating base to expose the copper layer, and at least one first conductive structure each infilled in one of the at least one first through hole;
• forming at least one middle structure, each of the middle structure being formed by:
• providing a laminated board comprising a metal layer, a third insulating base, a metal shielding layer, and a second insulating base arranged in that sequence;
• forming a wiring layer by the metal layer, the wiring layer comprising at least one signal wire and at least one connecting pad;
• defining at least one second through hole each passing through the second insulating base, the metal shielding layer, and the third insulating base to expose one of the at least one connecting pad;
• and
• forming a second conductive structure infilled in each of the at least one second through hole, wherein
• the laminated board is formed by:
• providing the second insulating base, and roughening a surface of the second insulating base;
• forming a seed layer on the roughened surface of the second insulating base;
• forming a metal thickening layer on a surface of the seed layer facing away from the second insulating base, the seed layer and the metal thickening layer forming the metal shielding layer;
• forming the third insulating base on a surface of the metal shielding layer facing away from the second insulating base;
• and
• forming the metal layer on a surface of the third insulating base facing away from the metal shielding layer, thereby obtaining the laminated board;
• providing a double-sided board comprising a wiring layer, a fourth insulating base, and a first copper foil arranged in that sequence, the wiring layer of the double-sided board comprising at least one signal wire and at least one connecting pad, the double-sided board further comprising at least one third conductive structure each connecting one of the at least one connecting pad and the first copper foil of the double-sided board;
• and
• pressing the single-sided board, the at least one middle structure, and the double-sided board in that sequence to form the circuit board;
• wherein each of the at least one first conductive structure connects one of the at least one connecting pad of an adjacent middle structure, each of the at least one connecting pad of the double-sided board connects one second conductive structure of the adjacent middle structure;
• when the circuit board comprises at least two adjacent middle structures, the two adjacent middle structures connect with each other by connecting the second conductive structure of one of the adjacent middle structures with the corresponding connecting pad of the adjacent middle structure.