Method of manufacturing a combined circuit board

A method of manufacturing a combined circuit board comprising:

• providing a rigid substrate comprising a rigid dielectric layer;
• forming a plurality of through portions in the rigid dielectric layer, wherein the through portions are arranged in a predetermined format and pass through the rigid dielectric layer such that the rigid substrate is divided into at least one predetermined removed region and at least one predetermined reserved region according to the arrangement of the through portions;
• providing a conductive bonding layer comprising a conductive layer and a dielectric bonding layer disposed on the conductive layer;
• laminating the conductive bonding layer on the rigid substrate such that a portion of the dielectric bonding layer is disposed between the conductive layer and the rigid substrate, and another portion of the dielectric bonding layer fills the through portions;
• laminating a flexible circuit board on the rigid substrate such that the flexible circuit board and the conductive layer are disposed on two opposite sides of the rigid substrate, respectively;
• patterning the conductive layer to form a circuit layer;
• bending the rigid substrate, the flexible circuit board, and the conductive bonding layer according to the through portions such that the at least one predetermined reserved region is bent at the through portions relatively to the at least one predetermined removed region;
• and
• removing a portion of the rigid substrate located at the at least one predetermined removed region and a portion of the conductive bonding layer corresponding to the at least one predetermined removed region to form an indentation to expose a portion of the flexible circuit board.