US Patent No. 9,832,888

CIRCUIT BOARD AND METHOD FOR MAKING THE SAME


Patent No. 9,832,888
Issue Date November 28, 2017
Title Circuit Board And Method For Making The Same
Inventorship Yan-Lu Li, Qinhuangdao (CN)
Mei Yang, Qinhuangdao (CN)
Cheng-Jia Li, Qinhuangdao (CN)
Assignee Avary Holding (Shenzhen) Co., Limited, Shenzhen (CN) HongQiSheng Precision...

Claim of US Patent No. 9,832,888

1. A method of manufacturing a circuit board, comprising:
providing a substrate with double-side copper layers, wherein the substrate comprises a base layer, a first copper layer and
a second copper layer, the first copper layer and the second copper layer are formed on opposite surfaces of the base layer;

opening a through hole on the substrate, wherein the through hole comprises a first hole and a second hole communicating with
the first hole, the first hole penetrates through the base layer and the second hole penetrates through the first copper layer;
forming a wire layer by copper plating, wherein the wire layer comprises a first portion filled in the through hole and a
second portion formed on the first portion extending in a direction facing away from the base layer, the wire layer is electrically
conductive between the first copper layer and the second copper layer through the first portion; wherein the manufacturing
method of forming the wire layer is further comprising the steps of:
applying a first photosensitive film and a second photosensitive film on the opposite surfaces of the substrate, the first
photosensitive film covers the first copper layer and the open end of the through hole, the second photosensitive film covers
the second copper layer;

forming a mask pattern on the first and second photosensitive films after exposing and developing the first and second photosensitive
films, the mask pattern comprises an opening which corresponds to the open end of the through hole, the aperture diameter
of the opening is less than the aperture diameter of the through hole;
forming a wire layer corresponding to the mask pattern by copper plating, the second portion is filled in the opening; and
removing the first and second photosensitive films; and
removing the first copper layer and the second copper layer which are not covered with the wire layer by using a quick etching
treatment so as to respectively form a first wire pattern layer and a second wire pattern layer, and the first portion which
is flush with the first copper layer and not cover with the second portion.