Patent ID: 11903133
Assignee: ZHUHAI ACCESS SEMICONDUCTOR CO., LTD.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 15:
16. The method for manufacturing according to claim 15, further comprising:
(j) following step (i), laminating an insulating material on the third circuit layer to form a fourth insulating layer, and forming a first blind hole and a second blind hole in the third insulating layer and the fourth insulating layer, respectively;
(k) forming a first via hole and a fifth circuit layer in the first blind hole and in the surface of the third insulating layer respectively, and forming a second via hole and a fourth circuit layer in the second blind hole and in the surface of the fourth insulating layer respectively, wherein the second circuit layer and the fifth circuit layer are conductively connected through the first via hole, and the third circuit layer and the fourth circuit layer are conductively connected through the second via hole; and
(l) forming a first solder resist layer on the fourth circuit layer, forming a second solder resist layer on the fifth circuit layer, and treating exposed metal surfaces in the first solder resist layer and the second solder resist layer respectively to form a first metal surface treatment layer and a second metal surface treatment layer.