Patent ID: 11871526
Assignee: HONGQISHENG PRECISION ELECTRONICS (QINHUANGDAO) CO., LTD
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A circuit board comprising:
a substrate comprising a base layer, a first metal layer formed on the base layer, and a seed layer formed on the base layer;
a first circuit layer located on the substrate and comprising the first metal layer and a signal layer formed on a surface of the first metal layer;
a second circuit layer coupled to the first circuit layer and comprising the first metal layer, the seed layer, and a connection pillar formed on a surface of the first metal layer and the seed layer; and
a third circuit layer coupled to the second circuit layer and comprising the seed layer and a coil formed on a surface of the seed layer, wherein a sheet resistance of the first metal layer is larger than a sheet resistance of the seed layer.