A printed circuit board may include a substrate body portion, conductive patterns on a top surface of the substrate body portion, and a photosensitive insulating layer on the top surface of the substrate body portion and including an opening exposing at least one of the conductive patterns. The photosensitive insulating layer includes first to third sub-layers stacked sequentially. The first sub-layer includes an amine compound or an amide compound. A refractive index of the second sub-layer is lower than a refractive index of the third sub-layer. A photosensitizer content of the second sub-layer is higher than a photosensitizer content of the third sub-layer.

Provided are a package substrate and a method for fabricating the package substrate. The method is to form a wiring structure on a circuit structure having a core layer. The circuit structure is served as a ball-attach side to reduce the number of layers of the package substrate. Accordingly, the overall thickness of the package substrate is advantageously reduced.

There is provided a photosensitive resin composition that contains (A) a photopolymerizable compound having an ethylenically unsaturated group, (X) organic particles, and (B) a photopolymerization initiator, in which the photopolymerizable compound (A) having an ethylenically unsaturated group contains (A1) a photopolymerizable compound having an acidic substituent and an alicyclic structure together with an ethylenically unsaturated group. There is provided a photosensitive resin film and a photosensitive resin film for interlayer insulating layer, each of which contains the photosensitive resin composition. There is provided a multilayer printed wiring board and a semiconductor package. There is further provided a method for producing the multilayer printed wiring board.