Disclosed are a method for fabricating a printed circuit board wherein through-holes are formed in an organic substrate, followed by forming micro-circuit patterns through sputtering and plating, whereby the printed circuit board has low permittivity properties and enables high-speed processing, and a printed circuit board fabricated thereby. The disclosed method for fabricating a printed circuit board comprises the steps of: preparing a base substrate; forming a through-hole perforating the base substrate; forming a thin seed layer on the base substrate and in the through-hole; forming a thin plate layer on the thin seed layer; and etching the thin seed layer and the thin plate layer to form a micro-circuit pattern, wherein the base substrate is one selected from an organic substrate, FR-4, and Prepreg.

A method of forming an electronic assembly. The method includes covering a patterned conductive layer that is on a dielectric layer with a solder resist; depositing a metal layer on to the solder resist; depositing a photo resist onto the metal layer; patterning the photo resist; etching the metal layer that is exposed from the photo resist to form a metal mask; removing the photo resist; and plasma etching the solder resist that is exposed from the metal mask. An electronic assembly for securing for an electronic card. The electronic assembly includes a patterned conductive layer that is on a dielectric layer; and a solder resist covering the patterned conductive layer and the dielectric layer, wherein the solder resist includes openings that expose the patterned conductive layer, wherein the openings in the solder resist only have organic material on side walls of the respective openings.

A circuit board includes a first dielectric material, a second dielectric material, a third dielectric material, a first external circuit layer, a second external circuit layer, multiple conductive structures, and a conductive via structure. Dielectric constants of the first, the second and the third dielectric materials are different. The first and the second external circuit layers are respectively disposed on the first and the third dielectric materials. The conductive via structure at least penetrates the first and the second dielectric materials and is electrically connected to the first and the second external circuit layers to define a signal path. The conductive structures are electrically connected to each other and surround the first, the second and the third dielectric materials. The conductive structures are electrically connected to the first and the second external circuit layers to define a ground path surrounding the signal path.

A circuit board includes a first substrate, a second substrate, a third substrate, a plurality of conductive structures and a conductive via structure. The second substrate is disposed between the first substrate and the third substrate. The third substrate has an opening and includes a first dielectric layer, a second dielectric layer, and a third dielectric layer. The opening penetrates the first dielectric layer and the second dielectric layer, and the third dielectric layer fully fills the opening. The conductive via structure penetrates the first substrate, the second substrate, the third dielectric layer of the third substrate, and is electrically connected to the first substrate and the third substrate to define a signal path. The first substrate, the second substrate, and the third substrate are electrically connected through the conductive structures to define a ground path, and the ground path surrounds the signal path.

A transparent PCB includes a transparent base film, a hardened layer, an electrode film, a first conductive paste, a second conductive paste, and an electronic component. The hardened layer is formed on a side of the transparent base film. The electrode film is formed on a side of the hardened layer. The electrode film includes a first transparent conductive oxide layer, a metal layer, and a second transparent conductive oxide layer. The first conductive paste is formed on the electrode film. The second conductive paste is formed on the electrode film and spaced from the first conductive paste. The electronic component is electrically connected to the electrode film through the first conductive paste and the second conductive paste. The present invention also needs to provide a method for manufacturing the transparent PCB.

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 and a valley portion void volume Vvv of 0.010 μm.sup.3/μm.sup.2 or more and 0.028 μm.sup.3/μm.sup.2 or less; 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.

In one example, an electronic device housing may include a substrate, an insulating adhesive layer formed on a surface of the substrate, a patterned electroless plating layer formed on the insulating adhesive layer, and a patterned electrolytic plating layer formed on the patterned electroless plating layer.

A wiring board includes a conductor pattern formed on a board, and an insulating film that covers at least part of the conductor pattern. A first insulating film is provided in a first region on the board, the first region covering at least part of the conductor pattern and having a first border segment. A second insulating film is provided in a second region on the board, the second region covering at least part of the first region and having a second border segment. The second border segment is located outside the first region, and the shortest distance from any point belonging to the second border segment to the first border segment is not more than 400 μm.

A circuit board includes a first dielectric material, a second dielectric material, a third dielectric material, a first external circuit layer, a second external circuit layer, multiple conductive structures, and a conductive via structure. Dielectric constants of the first, the second and the third dielectric materials are different. The first and the second external circuit layers are respectively disposed on the first and the third dielectric materials. The conductive via structure at least penetrates the first and the second dielectric materials and is electrically connected to the first and the second external circuit layers to define a signal path. The conductive structures are electrically connected to each other and surround the first, the second and the third dielectric materials. The conductive structures are electrically connected to the first and the second external circuit layers to define a ground path surrounding the signal path.

A method for producing an electrically conductive thin film on a substrate is disclosed. Initially, a reducible metal compound and a reducing agent are dispersed in a liquid. The dispersion is then deposited on a substrate as a thin film. The thin film along with the substrate is subsequently exposed to a pulsed electromagnetic emission to chemically react with the reducible metal compound and the reducing agent such that the thin film becomes electrically conductive.