A solder composition for use in solder joints of printed circuit boards (PCBs), including a compound layer comprising an alloy of bismuth and tin; and a graphene coating positioned on the compound layer.

A printed circuit board includes: an insulating layer; a conductive pattern disposed within the insulating layer; a skin layer disposed on the insulating layer and having an opening on the conductive pattern; and a connection layer at least partially surrounded by the skin layer, disposed in the opening to connect to a portion of the conductive pattern, and containing gold (Au).

A method reduces an area of a mounting electrode provided on a first surface of a multilayer body and connected to a specific component is reduced and decreases a pitch between mounting electrodes. A plating film is formed on the mounting electrodes with the reduced area. The mounting electrodes for connection to specific components are defined by first end surfaces of first via conductors, and hence, the areas of the mounting electrodes are significantly reduced, and the pitch between the mounting electrodes is significantly decreased. Also, the mounting electrodes defined by the first end surfaces of the first via conductors are connected to plane electrodes at end surfaces of second via conductors exposed from a surface of the multilayer body with internal wiring electrodes interposed therebetween. Thus, a plating film is able to be reliably provided on the mounting electrodes.

A high frequency signal transmission structure includes an insulating sheet and a conductive wiring layer forming on the insulating sheet. The conductive wiring layer includes a silver conductive layer forming on the insulating sheet, a copper conductive layer forming on the silver conductive layer, and a silver covering layer covering a top surface and side surfaces of the copper conductive layer. The silver conductive layer and the silver covering layer together surround the copper conductive layer.

A method for interconnecting two conductors includes creating a first nickel layer on a first conductor of an electrical component, producing a first non-gold protective layer on the first nickel layer, the first non-gold protective layer being configured to prevent the first nickel layer from oxidizing, creating a second nickel layer on a second conductor, producing a second non-gold protective layer on the second nickel layer, the second non-gold protective layer being configured to prevent the second nickel layer from oxidizing, and interconnecting the first and second nickel layers using a solder layer that interfaces with the first and second nickel layers between the first and second conductors.

Embodiments of the present disclosure are directed towards techniques and configurations for dual surface finish package substrate assemblies. In one embodiment a method includes depositing a first surface finish on one or more electrical routing features located on a first side of a package substrate and on one or more lands located on a second side of the package substrate, the second side being opposite the first side of the substrate. The method may further include removing the first surface finish on the first side of the package substrate; and depositing a second surface finish on the one or more electrical routing features of the first side. The depositing of the second surface finish may be accomplished by one of a Direct Immersion Gold (DIG) process or an Organic Solderability Preservative (OSP) process. Other embodiments may be described and/or claimed.

Disclosed is a circuit board having a contact pad for connection with an external device, which protrudes from an upper surface of an outermost insulating layer. A device can be mounted on the circuit board, and a connection terminal of the device can be connected to the contact pad of the circuit board by a wire etc.

A circuit board includes a substrate, a plurality of contacts disposed on a surface of the substrate, and a solder mask. The contacts have a plurality of plating regions and a metal layer on the plating regions, and the plating regions have at least two different sizes. The solder mask covers the surface of the substrate and covers edges of the plating regions, in which topmost surfaces of the contacts are below a top surface of the solder mask, and a gap between the topmost surfaces of the contacts and the top surface of the solder mask is larger than 0 μm and is smaller than 5 μm.

A method for manufacturing a multilayer circuit board includes: forming a first patterned conductive layer on a ceramic substrate, the first patterned conductive layer having a first circuit pattern and a first submount pattern; forming a second patterned conductive layer on the first patterned conductive layer, the second patterned conductive layer having a second circuit pattern and a second submount pattern; forming an insulating layer on the ceramic substrate; and forming a third patterned conductive layer on the insulating layer. The third patterned conductive layer having a third circuit pattern and a third submount pattern. The first, second and third submount patterns are stacked one above another.

A method for interconnecting two conductors includes creating a first nickel layer on a first conductor of an electrical component, producing a first non-gold protective layer on the first nickel layer, the first non-gold protective layer being configured to prevent the first nickel layer from oxidizing, creating a second nickel layer on a second conductor, producing a second non-gold protective layer on the second nickel layer, the second non-gold protective layer being configured to prevent the second nickel layer from oxidizing, and interconnecting the first and second nickel layers using a solder layer that interfaces with the first and second nickel layers between the first and second conductors.