A printed circuit board (PCB) includes: a substrate; and a circuit pattern disposed on the substrate, wherein the circuit pattern includes a first seed layer disposed on the substrate and including a nitride, and a metal layer disposed on the first seed layer.

A display apparatus includes a display panel having a display substrate on which a plurality of pad terminals is disposed, and a driving unit having a plurality of driving terminals electrically connected to the plurality of pad terminals. Each of the plurality of pad terminals includes a stepped groove that faces a corresponding driving terminal of the plurality of driving terminals or each of the plurality of pad terminals includes an opening hole that faces the corresponding driving terminal of the plurality of driving terminals.

A method includes providing a layer of non-conductive material having a conductive electroplating seed layer formed on a surface thereof; applying a photoresist layer over the surface of the conductive electroplating seed layer; and defining wiring channels in the photoresist resist layer. The method includes electroplating a conductive material in the defined wiring channels; adhering a non-conductive layer over the photoresist layer and the plated conductive material in the wiring channels; and removing the layer of non-conductive material and the conductive electroplating seed layer.

A module substrate for a semiconductor module including a wiring substrate having an upper surface and a lower surface opposite to each other and including a wiring formed therein, the wiring substrate having at least one through groove in at least one sidewall and extending in a thickness direction, and a through-groove test terminal including at least one contact pad, a surface of the contact pad being exposed from an inner wall of the through-groove, the contact pad being spaced apart from a vertical plane extending from the sidewall of the wiring substrate may be provided.

Provided is a double layer circuit board and a manufacturing method thereof. The double layer circuit board comprises a substrate, a first circuit layer formed on a first surface of the substrate, a second circuit layer formed on a second surface of the substrate, and at least one connecting pillar formed in and covered by the substrate. Each one of the at least one connecting pillar includes a first end connected to the first circuit layer and a second end connected to the second circuit layer. A terminal area of the second end is greater than a terminal area of the first end. Therefore, the second circuit layer is firmly connected to the first circuit layer through the at least one connecting pillar. A yield rate of the double layer circuit board may be increased.

A board-to-board connecting structure which adds no significant thickness to a single printed circuit board includes a first circuit board and a second circuit board. The first circuit board includes first circuit substrate, adhesive layer, and second circuit substrate. The first circuit substrate includes first base layer, first inner wiring layer with first pad, and first outer wiring layer defining a receiving space. The second circuit substrate includes insulating layer and two second outer wiring layers. A conductive via in the second circuit substrate connects the two second outer wiring layers. The second circuit board includes second base layer and also two third outer wiring layers each with a second pad. The second circuit board is laterally disposed in the receiving space and one second pad connects to the conductive via and the other to the first pad.

A wiring substrate includes an insulating layer including inorganic filler particles and resin, and a conductor layer including a metal film formed on a surface of the insulating layer and having a conductor pattern. The inorganic filler particles include first inorganic filler particles such that each of the first inorganic filler particles has a portion exposed on the surface of the insulating layer and is at least partially separated from the resin, the conductor layer is formed such that a part of the metal film is between the first inorganic filler particles and the resin from the surface of the insulating layer and that a distance between the surface of the insulating layer and the surface of the insulating layer at a deepest part of the part of the metal film is in the range of 0.1 μm to 0.5 μm.

A printed wiring board includes a laminated base material including an insulating layer and a conductor layer formed on the insulating layer, and a solder resist layer laminated on the laminated material and including photosensitive resin. The resist layer has surface portion and portion in contact with the laminated material, the conductor layer has pattern including conductor pads in contact with the resist layer such that the pads are positioned in openings in the resist layer, and the resist layer satisfies a first condition that a chemical species derived from a photopolymerization initiator has concentration higher in the portion in contact with the laminated material than concentration in the surface portion and/or a second condition that the chemical species derived from the initiator in the portion in contact with the laminated material has photopolymerization initiating ability higher than a chemical species derived from a photopolymerization initiator in the surface portion.

There is provided a wiring board capable of strengthening the bonding between an external terminal and a wiring of an external circuit board. A wiring board includes an insulating substrate having two main surfaces facing each other, side surfaces connecting to the two main surfaces and concave portions concave from the side surfaces and connecting to at least one of the two main surfaces; and external terminals disposed from one of the main surfaces to inner surfaces of the respective concave portions, each of the external terminals having a convex-shaped section disposed on one main surface side along each of the concave portions.

A wiring board includes: a metal plate having first and second surfaces opposite to each other, and having at least one through-hole penetrating through the first and second surfaces; at least one conductive via respectively disposed in the through-hole and spaced apart from the metal plate; an insulating structure including at least one through-insulating portion disposed between the through-hole and the conductive via, and a first insulating layer and a second insulating layer extending from the through-insulating portion and disposed in first regions surrounding the conductive via, on the first surface and the second surface, respectively; at least one first upper pad disposed on the first insulating layer and electrically connected to the conductive via; at least one first lower pad disposed on the second insulating layer and electrically connected to the conductive via; a second upper pad disposed on the first surface of the metal plate; and a second lower pad disposed on the second surface of the metal plate and electrically connected to the first upper pad through the metal plate.