Method for manufacturing semi-flex printed circuit board

A method for manufacturing a semi-flex printed circuit board, comprising:

• providing a core substrate;
• forming two metal dam structures convex from a side surface of the core substrate and two laser cut grooves concave from the side surface of the core substrate, wherein inner sides of the two metal dam structures form a printing area at the side surface of the core substrate, and the positions of the two laser cut grooves correspond to the printing area and are closely adjacent to the inner sides of the two metal dam structures respectively;
• printing a strippable printing ink in the printing area on the core substrate, wherein the strippable printing ink is capable of being filled in the two laser cut grooves during a printing process;
• laminating a build-up board structure on the side surface of the core substrate, and blind routing another side surface of the core substrate to form two blind routing openings, which correspond to the two laser cut grooves in position respectively;
• removing a cover-opening structure of the core substrate between the two blind routing openings, so as to form a cover-opening opening, and the cover-opening structure is separated from the build-up board structure from positions of the two laser cut grooves;
• and
• removing residual ink located at the bottom of the cover-opening opening;
• wherein the build-up board structure comprises a bonding sheet and a core board, and the bonding sheet is arranged between the core substrate and the core board, wherein a side surface of the bonding sheet is bonded to the strippable printing ink and the two metal dam structures, and is further trapped in a gap at outer sides of the two metal dam structures to be bonded to the core substrate, and another side surface of the bonding sheet is bonded onto the core board, so as to bond the core substrate and the core board together.