There is provided a method for manufacturing a printed wiring board that effectively suppresses pattern failure and is also excellent in fine circuit forming properties. This method includes: providing an insulating substrate including a roughened surface; performing electroless plating on the roughened surface of the insulating substrate to form an electroless plating layer less than 1.0 μm thick having a surface having an arithmetic mean waviness Wa of 0.10 μm or more and 0.25 μm or less as measured in accordance with JIS B0601-2001 and a kurtosis Sku of 2.0 or more and 3.5 or less as measured in accordance with ISO 25178; laminating a photoresist on the surface of the electroless plating layer; performing exposure and development to form a resist pattern; applying electroplating to the electroless plating layer; stripping the resist pattern; and etching away an unnecessary portion of the electroless plating layer to form a wiring pattern.

A method for forming a thermal and electrical path in a PCB may include forming a first removable layer over a top surface of a PCB and a second removable layer over a bottom surface of the PCB. The method may also include milling or laser drilling the PCB from the top surface to form a first cavity extending into the PCB, plating the first side panel plating the first side with a second metal to partially fill the first cavity; and milling or laser drilling from the bottom surface to form a second cavity extending into the PCB, the first cavity in a thermal communication and/or an electrical communication with the second cavity. The method may also include panel plating the first side with a second metal to fill the first cavity and the second side with the second metal to fill the second cavity, and removing the first and second removable layers from the PCB to form the PCB with a thermal and/or an electrical path comprising the first cavity and the second cavity filled with the second metal.

A printed circuit board includes a first insulating layer; a pad disposed on the insulating layer and having a protrusion; and a protective layer disposed on the insulating layer and having an opening exposing at least a portion of the pad. The protrusion protrudes from one surface of the pad and is buried in at least one of the insulating layer and the protective layer.

A circuit board includes a substrate, a first circuit layer, a second circuit layer, and a third circuit layer. The substrate includes a base layer, a first metal layer formed on the base layer, and a seed layer formed on the first metal layer. The first circuit layer is located on the substrate and includes the first metal layer and a signal layer formed on a surface of the first metal layer. The second circuit layer is coupled to the first circuit layer and includes the first metal layer, the seed layer, and a connection pillar formed on a surface of the first metal layer and the seed layer. The third circuit layer is coupled to the second circuit layer and includes the seed layer and a coil formed on a surface of the seed layer.

A patterned conductive article 200 includes a substrate 210 including a unitary layer 210-1 and includes a micropattern of conductive traces 220 embedded at least partially in the unitary layer. Each conductive trace extends along a longitudinal direction (y-direction) of the conductive trace and includes a conductive seed layer 230 having a top major surface 232 and an opposite bottom major surface 234 in direct contact with the unitary layer; and a unitary conductive body 240 disposed on the top major surface of the conductive seed layer. The unitary conductive body and the conductive seed layer differ in at least one of composition or crystal morphology. The unitary conductive body has lateral sidewalls 242, 244 and at least a majority of a total area of the lateral sidewalls is in direct contact with the unitary layer.

According to one aspect of the present disclosure, a printed circuit board includes: an insulating base film; and a plurality of wiring portions formed on a surface of the base film, wherein the wiring portions include a seed layer that is directly or indirectly layered on the surface of the base film and a metal layer that is layered on the seed layer, wherein the base film has a wiring area including the plurality of wiring portions and a non-wiring area not including the wiring portions, wherein the plurality of wiring portions include at least one outermost boundary wiring portion and a plurality of inner wiring portions other than the outermost boundary wiring portion, wherein the outermost boundary wiring portion is formed on an outermost side of the base film in the wiring area and at a boundary between the wiring area and the non-wiring area, wherein an average width of the outermost boundary wiring portion is 30 μm or more, wherein an average width of the inner wiring portions is 20 μm or less, and wherein an average aspect ratio of the inner wiring portions is 1.5 or more.

Provided is a copper-clad laminate in which a copper foil and a resin are joined together with high heat-resistant adhesion force though a fluororesin is used. This copper-clad laminate includes a surface-treated copper foil including a copper foil and a zinc-containing layer on at least one surface of the copper foil; and a sheet-shaped fluororesin on the zinc-containing layer side of the surface-treated copper foil. The zinc-containing layer is composed of Zn and a transition element M having a melting point of 1200° C. or more. When the interface between the copper foil and the zinc-containing layer is subjected to elemental analysis by GD-OES, the emission intensity ratio I.sub.Zn/I.sub.Cu of the emission intensity of Zn to that of Cu is 3.0×10.sup.−3 or less, and the emission intensity ratio I.sub.Zn/I.sub.M of the emission intensity of Zn to that of the transition element M is 0.30 to 0.50.

A package substrate and a manufacturing method thereof are disclosed. The method includes: providing an inner substrate; processing an adhesive photosensitive material on a surface of a first side of the inner substrate to obtain an adhesive first insulating dielectric layer; mounting a component on the first insulating dielectric layer; and processing a photosensitive packaging material on the first side of the inner substrate to obtain a second insulating dielectric layer, where the second insulating dielectric layer covers the component.

A circuit board includes a first outer wiring layer, a circuit substrate, and a second outer wiring layer stacked. The circuit substrate includes a first inner wiring layer, an insulating layer, and a second inner wiring layer stacked. A plurality of thermally conductive pillars is arranged at intervals on the first inner wiring layer, a liquid storage space is formed between every two adjacent thermally conductive pillars, and a thermally conductive agent is received in the liquid storage space. The first outer wiring layer is formed on the plurality of thermally conductive pillars. The second outer wiring layer is formed the second inner wiring layer. A first groove penetrates the second outer wiring layer, the second inner wiring layer and the insulating layer, exposes a portion of the first inner wiring layer, and corresponds to the thermally conductive pillars. At least one heating element is installed in the first groove.

A printed circuit board includes an insulating layer; a metal pad disposed on one side of the insulating layer; a via hole penetrating through the insulating layer to expose at least a portion of the metal pad; and a via filling at least a portion of the via hole, wherein the via comprises a first metal layer and a second metal layer disposed on the first metal layer, and an average size of grains in the first metal layer and an average size of grains in the second metal layer are different from each other.