Abstract: A method for producing a wiring circuit board assembly sheet includes a marking step of forming a mark made of a recessed portion in a metal support board, and after the marking step, an insulating layer forming step of forming a base insulating layer on one surface in a thickness direction of the metal support board formed with the mark.

Abstract: A wiring circuit board includes a metal supporting substrate, an insulating layer, and a conductive layer in this order in a thickness direction. The conductive layer includes at least one terminal portion and a wiring portion extending from the terminal portion. The metal supporting substrate has an opening portion. The opening portion penetrates the metal supporting substrate in the thickness direction and faces the terminal portion through the insulating layer. The opening portion has a first opening peripheral edge on one side in the thickness direction and a second opening peripheral edge on the other side in the thickness direction. In a projected view in the thickness direction, the second opening peripheral edge is disposed outside the first opening peripheral edge and extends along the first opening peripheral edge.

Abstract: A wiring circuit board includes an insulating layer, a pair of wiring layers, an insulating layer, and a wiring layer. The pair of wiring layers are disposed on the insulating layer and extend side by side apart from each other. The insulating layer is disposed on the insulating layer so as to cover the pair of wiring layers. The wiring layer is disposed on the insulating layer and extends along the pair of wiring layers, while facing to the pair of wiring layers in a thickness direction of the wiring layer. The wiring layer has a ridge portion. The ridge portion protrudes into the insulating layer toward a region between the wiring layers and extends along the region.