Patent ID: 11917769
Assignee: SHENZHEN KINWONG ELECTRONIC CO., LTD.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 7:
8. The method for fabricating an asymmetric board according to claim 7, wherein in the step of removing copper, copper removed area and connection portions located outside the copper removed area are formed on the connection areas of the third copper layer, the step of thermal compression bonding further comprises removing the connection portions, and the depth control groove having a minimum depth D0 min=H1−H4+ΔX and a maximum depth D0 max=H1−H4+H3−ΔX, wherein the H1 represents a thickness of the third copper layer, the H3 represents a thickness of the prepreg, the H4 represents a thickness of the third copper layer, and the ΔX represents a precision tolerance of a depth control milling machine.