Patent ID: 11910535
Assignee: UNIMICRON TECHNOLOGY CORP.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 2:
3. The printed circuit board stack structure according to claim 2, wherein the first printed circuit board further comprises a first solder resist layer, a second solder resist layer, a first surface treatment layer, and a second surface treatment layer,
the first solder resist layer is located on the first surface and has a plurality of first solder resist openings,
the first solder resist openings expose the first pads and some of the third pads,
the second solder resist layer is located on the second surface and has a plurality of second solder resist openings,
the second solder resist openings expose some of the fourth pads,
the first surface treatment layer is located on the fourth pads exposed by the second solder resist openings, and
the second surface treatment layer is located on the third pads exposed by the first solder resist openings.