Abstract: The present application relates to the technical field of circuit board fabricating, and provides a method for fabricating an asymmetric board, the method includes fabricating a master board, fabricating a second sub-board, thermal compression bonding the master board and the second sub-board, and milling an asymmetric board; further includes at least one of the following three steps: laying copper on the connection areas of the master board except for the second copper layer of an outermost layer to obtain laying copper area, removing copper on the connection areas of the third copper layer, and after the step of milling the asymmetric board, on each of the sub-boards, performing depth control milling at the connection areas from a side of the second sub-board on each sub-board to obtain a depth control groove.

Abstract: The present application provides an asymmetric board, which includes the first master board, the second master board, and the insulating dielectric layer sandwiched between the first master board and the second master board, and the depth control grooves are disposed in the connection position between the units on the asymmetric board, and located on the surface of the second master board and extending a toward the side of the first master board, the depth control grooves provide space for the expansion of the second master board, reduce the stress of the units, and reduce the warping of the second master board. When the number of the depth control grooves in the first direction and/or the second direction is greater than 0, the depths of the depth control grooves increase by X from a center to an edge of the asymmetric board, and the X is greater than or equal to 0.