▎ 摘　　要

NOVELTY - Surface treatment of through-holes of printed circuit board (110) involves (s1) impregnating the printed circuit board containing through-holes in a solution comprising a charged and reduced graphene oxide to form a charged and reduced graphene oxide layer (120) in the through-holes, and (s2) cleaning the printed circuit board. USE - Surface treatment of through-holes of printed circuit board such as multilayer printed circuit board (all claimed) for electronic products. ADVANTAGE - The method is economical, and enables surface treatment of through-holes of printed circuit board capable of forming high-quality plating layer by forming a reliable surface treatment layer, and having suppressed the generation of voids, excellent electroconductivity, and does not smooth due to the flexibility of graphene. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) the printed circuit board; (2) plating of printed circuit board; and (3) a multilayer printed circuit board. DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of the printed circuit board. Printed circuit board (110) Charged and reduced graphene oxide layer (120)