Provided is a landless multilayer circuit board and a manufacturing method thereof. The manufacturing method includes steps of forming a first circuit on a first substrate, patterning a photoresist layer to form at least one via between the first circuit and a second circuit, forming at least one connecting pillar in the at least one via, removing the photoresist layer, forming a second substrate to cover the at least one connect pillar, and forming the second circuit on the second substrate. The second circuit is connected to the first circuit through the at least one connecting pillar. When the second circuit is formed, the at least one via does not need to be filled, thereby making the second circuit flat.

A method is provided for fabricating an electromagnetic shield for an electronic component on a PCB. The method includes providing a patterned metal layer; laminating the patterned metal layer with a second dielectric layer; forming a cavity in the second dielectric layer; applying a dry film resist over the second dielectric layer and the cavity; stripping the dry film resist from the second dielectric layer and portions of the cavity adjacent the cavity side walls; depositing a seed layer and metal over the second dielectric layer and the dry film resist; etching the preplating layer and the seed layer from top surfaces of a remainder of the dry film resist and the second dielectric layer; and stripping the remainder of the dry film resist, thereby exposing the preplating layer on the side walls of the cavity to provide the electromagnetic shield.

A circuit structure and a fabrication method thereof are provided. The fabrication method of the circuit structure includes the following steps: providing a substrate; fabricating a test circuit component on the substrate; fabricating a solder pad on the test circuit component; fabricating an insulating layer; and fabricating a conductive pad on the insulating layer. A second surface of the insulating layer covers the test circuit component and the solder pad. The conductive pad is coupled to the solder pad. Through the fabrication method of the circuit structure provided by the disclosure, circuit quality of the circuit structure may be monitored, and that reliability of the circuit structure provided by the disclosure is improved.

A printed wiring board includes a base insulating layer, a conductor layer formed on the base layer and including conductor pads, an underlayer formed on one of the conductor pads and including a metal different from a metal of the conductor layer, a solder resist layer formed on the base layer such that the solder resist layer is covering the conductor layer and has openings exposing the conductor pads, and a bump formed directly on a first conductor pad of the conductor pads and including a base plating layer formed in a first opening of the openings and a top plating layer formed on the base plating layer such that a metal of the base plating layer is same as the metal of the conductor layer. The conductor pads include a second conductor pad such that the second conductor pad is the one of the conductor pads having the underlayer.

A printed wiring board includes a base insulating layer, a conductor layer formed on the base layer and including conductor pads, an underlayer formed on one of the conductor pads and including a metal different from a metal of the conductor layer, a solder resist layer formed on the base layer such that the solder resist layer is covering the conductor layer and has openings exposing the conductor pads, and a bump formed directly on a first conductor pad of the conductor pads and including a base plating layer formed in a first opening of the openings and a top plating layer formed on the base plating layer such that a metal of the base plating layer is same as the metal of the conductor layer. The conductor pads include a second conductor pad such that the second conductor pad is the one of the conductor pads having the underlayer.

A method for optimized filling holes and manufacturing fine lines on a printed circuit board (PCB) carries out the two processes separately. The inner wall of the hole is metalized with reduced graphene oxide (rGO) and then electroplated to fill the hole with copper. The processes are individually performed and thus operating parameters are considered independently. As a result, the copper-plating fillings are evenly compact and the fine lines have square profiles.

A circuit board including a substrate, a patterned conductive layer, a patterned insulating layer, a conductive terminal, and a dummy terminal is provided. The patterned conductive layer is disposed on the substrate. The patterned insulating layer is disposed on the substrate and at least covers a portion of the patterned conductive layer. The conductive terminal is disposed on the patterned conductive layer and has a first top surface. The dummy terminal is disposed on the patterned conductive layer and has a second top surface. A first height between the first top surface and the substrate is greater than a second height between the second top surface and the substrate.

A method for optimized filling holes and manufacturing fine lines on a printed circuit board (PCB) carries out the two processes separately. The inner wall of the hole is metalized with reduced graphene oxide (rGO) and then electroplated to fill the hole with copper. The processes are individually performed and thus operating parameters are considered independently. As a result, the copper-plating fillings are evenly compact and the fine lines have square profiles.

A printed wiring board includes a base insulating layer, a conductor layer formed on the base insulating layer and including conductor pads, an underlayer formed on one of the conductor pads of the conductor layer and including a metal different from a metal of the conductor layer, a solder resist layer formed on the base insulating layer such that the solder resist layer is covering the conductor layer and has openings exposing the conductor pads, respectively, and a bump formed directly on a first conductor pad of the conductor pads and including a base plating layer formed in a first opening of the openings and a top plating layer formed on the base plating layer such that a metal of the base plating layer is same as the metal of the conductor layer.

A multilayer wiring board that improves the reliability of connection at a via hole connection portion, and a method for producing the multilayer wiring board. In a multilayer wiring board comprising a plurality of metal wiring layers alternately laminated with insulating layers interposed therebetween are electrically connected to each other via a via hole plated layer, wherein a dissimilar metallic layer, made from material different from that of the metal wiring layers, is interposed between each of the metal wiring layers on the bottom surface of the via hole and the via hole plated layer, and the dissimilar metallic layer interposed between the each of the metal wiring layers on the bottom surface of the via hole and the via hole plated layer is arranged in a concave shape on the surface of the concave portion formed in the metal wiring layer on the bottom surface of the via hole.