A printed wiring board includes an insulating layer, a first conductor layer embedded into a first surface of the insulating layer and including connecting portions to connect an electronic component, a second conductor layer projecting from a second surface of the insulating layer, a solder resist layer covering the first conductor layer and having an opening structure exposing the connecting portions, a barrier metal layer formed on the connecting portions such that the barrier layer is projecting from the first surface of the insulating layer, and metal posts formed on the barrier layer such that the metal posts are positioned on the connecting portions, respectively. Each metal post has width which is greater than width of a respective connecting portion, and the barrier metal layer includes a metal material which is different from a metal material forming the metal posts and a metal material forming the first conductor layer.

A power electronic system with conductor having damping function is provided. The power electronic system includes power components and a conductor. The conductor is configured to connect the power components, and includes a damping part disposed on a surface of the conductor. The damping part is at least partially formed with a damping material having different resistances at different frequencies, and a relative permeability of the damping material is greater than 1 at a frequency higher than 1 MHz. The damping part forms first and second paths for first and second power currents flowing between the power components respectively, the first power current is at a frequency higher than 1 MHz, the second power current is at a frequency lower than 1 MHz, and a resistance of the first path is higher than a resistance of the second path.

According to one embodiment, a printed circuit board includes a first conductive layer on an insulating layer, including connection pads, a first mounting pad, a second mounting pad, a second wiring connecting the first mounting pad and one of the connection pads, and a first reinforcing pattern extending from the second mounting pad, a second conductive layer on another surface of the insulating layer, including a third wiring connected to one of the connection pads, and a conductive via connecting the second mounting pad and the third wiring. The second conductive layer includes a pad portion on the third wiring, opposed to the second mounting pad, and a third reinforcing pattern extending from the pad portion and opposed to the first reinforcing pattern.

The present disclosure provides an elastic interposer including a flexible substrate and a conductive device. The flexible substrate includes multiple circuits, of which first terminals are exposed on a first surface of the flexible substrate and show a first pattern, and of which second terminals are exposed on a second surface of the flexible substrate and show a second pattern different from the first pattern. The conductive device includes a first flexible conductive element and a second flexible conductive element. The first flexible conductive element is disposed on the first surface of the flexible substrate, and includes multiple first elastic conductive portions electrically connected to the first terminals of the circuits. The second flexible conductive element is disposed on the second surface of the flexible substrate, and includes multiple second elastic conductive portions electrically connected to the second terminals of the circuits.