After a copper plate 14 is bonded to at least one surface of a ceramic substrate 10 via an active metal containing brazing filler metal 12 which contains silver, the unnecessary portion of the copper plat 14 and active metal containing brazing filler metal 12 is removed, and thereafter, an unnecessary portion of the copper plate 14 is removed by chemical polishing so as to cause the active metal containing brazing filler metal 12 to protrude from the side face portion of the copper plate 14, and then, a silver layer 18 adhered to the surface of the copper plate 14 by the chemical polishing is removed.

A circuit board (10, 10, 10) includes at last one insulating substrate layer (SL1, SL2, SL3, SL4, SL5) and a plurality of electrically conductive copper coats (C1, C2, C3) arranged on the at least one insulating substrate layer (SL1, SL2, SL3, SL4, SL5), wherein at least one of the electrically conductive copper coats (C1, C2, C3) is coated at least on both sides with a layer (HSI, HS2, HS3) made of a material for inhibiting electromigration, wherein on a layer (HS1, HS2) made of a material for inhibiting electromigration a further metal layer (M1, M2, M3, M3) is provided, which is in turn coated with a further layer (HS3, HS3) made of a material for inhibiting electromigration.

A circuit assembly (200) is disclosed comprising a substrate (210) and conducting layers (250) on opposing sides of the substrate (210), there being at least one via (220) through the substrate (210), which via (220) forms a conductive path between the conducting layers, wherein the substrate (210) is a foam substrate, and wherein the via (220) is provided with a solid dielectric lining (270) plated with a conducting material (250).

A method of manufacturing a circuit substrate includes the steps of preparing a conductor paste in which a powder of at least one of a metal boride and a metal silicide is added to a powder of silver (Ag), applying the conductor paste to a surface of a ceramic substrate which has been fired, applying a glass paste to the surface of the ceramic substrate after applying the conductor paste, firing the conductor paste applied to the surface so as to form a conductor trace, and firing the glass paste applied to the surface so as to form a coating layer.

A wiring board includes an insulating layer, and a metal layer. The insulating layer includes a first pattern and a second pattern. The first pattern includes first grooves extending parallel to each other, and a first projecting part separating adjacent first grooves. The second pattern includes a second projecting part, and a second groove surrounding the second projecting part. The metal layer includes a wiring formed within the first grooves, and a degassing hole formed within the second pattern and having an opening formed by the second projecting part.

A nanocomposite coating composition for use in the mitigation of whisker growth from a metallic surface (82) includes a polymer matrix (86) comprising a base polymer and insulating material nanoplatelets (85), for example clay nanoplatelets, within the polymer matrix (86). A conformal coating (84) for application to a metal surface (82) is formed from the coating composition. The conformal coating mitigates the spontaneous growth of whiskers (83), in particular tin whiskers, from the coated surface (82), reducing the risk of short-circuits caused by such whiskers bridging gaps within electronic devices. Methods are provided for the preparation of coating compositions and coatings.

A wiring board includes an insulating layer, and a metal layer. The insulating layer includes a first pattern and a second pattern. The first pattern includes first grooves extending parallel to each other, and a first projecting part separating adjacent first grooves. The second pattern includes a second projecting part, and a second groove surrounding the second projecting part. The metal layer includes a wiring formed within the first grooves, and a degassing hole formed within the second pattern and having an opening formed by the second projecting part.

A highly thermally conductive printed circuit board prevents electrochemical migration by inhibiting elution of copper ions. The printed circuit board is a metal-base printed circuit board including a metal base plate having an insulating resin layer and a copper foil layer stacked thereon in this order. In the printed circuit board, the insulating resin layer contains a first inorganic filler made of inorganic particles having particle diameters of 0.1 nm to 600 nm with an average particle diameter (D.sub.50) of 1 nm to 300 nm, and a second inorganic filler made of inorganic particles having particle diameters of 100 nm to 100 m with an average particle diameter (D.sub.50) of 500 nm to 20 m, and the first inorganic filler and the second inorganic filler are uniformly dispersed in the insulating resin layer.

In one embodiment, an apparatus includes a plurality of layers in a circuit board, each of the layers comprising a fiber weave, two plated holes extending through the layers and connecting two or more of the layers, and a non-plated hole interposed between the plated holes. The non-plated hole passes through a potential CAF (Conductive Anodic Filament) migration path along the fiber weave to prevent CAF formation between the plated holes.

A flexible wiring board (a first wiring board) includes: an insulating substrate which is flexible; a first terminal which is conductive and is disposed on the insulating substrate; a second terminal which is conductive and is disposed on the insulating substrate; and a no-connection (NC) terminal which is conductive and is disposed on the insulating substrate between the first terminal and the second terminal. The first terminal, the NC terminal, and the second terminal are arranged at a uniform pitch in an arranging direction that is predetermined, and a width of the NC terminal in the arranging direction is smaller than a width of the first terminal in the arranging direction and a width of the second terminal in the arranging direction.