A substrate conductive bonding structure includes a lower substrate including a connection pad exposed to outside the lower substrate, an upper substrate including a transfer pad overlapping the connection pad, exposed to outside the upper substrate and including an upper surface, and a slit defined in the transfer pad, overlapping the connection pad and open at the upper surface of the transfer pad, the slit including an extending portion extending along a first direction and having a first slit width along a second direction crossing the first direction, and an expansion portion connected to the extending portion and having a second slit width along the second direction which is larger than the first slit width, and a solder contacting the upper surface of the connection pad, extending to the upper surface of the transfer pad and into the slit.

A resin substrate includes a resin base material including a first main surface, electrode pads provided on the first main surface, circuit conductor patterns, a resist film, and a coverlay film. The resist film includes, on the outer circumference, a plurality of protruding portions each of which has a tapered shape with a vertex. A portion of the circuit conductor patterns are covered with the resist film, and the coverlay film covers a portion of the resist film including the protruding portions and exposed portions of the circuit conductor patterns. The protruding portions are located at positions sandwiching the exposed portions of the circuit conductor patterns.

The present disclosure provides an electronic device including a substrate, a first pad, a second pad and an integrated circuit chip. The first pad is disposed on the substrate. The second pad is disposed on the first pad and electrically connected to the first pad. The integrated circuit chip is disposed on the second pad and is electrically connected to the second pad. The second pad has a plurality of curved corners.

A power supply circuit board includes a substrate, a first line that is provided on a first main surface of the substrate and that has a land, a second line that is provided on the first main surface of the substrate and that has a land, an inductor that is connected to the land of the first line and the land of the second line and that is made of a ferrite material, and an open stub that is connected to at least one of the first line and the second line.

A method for manufacturing such multilayer printed circuit board includes providing a metal laminated structure including a first type metal layer and a second type metal layer, pressing a patterned dry film layer and a protective film layer on two surfaces of the metal laminated structure, the dry film layer exposing the second type metal layer; etching the second type metal layer to form a first conductive circuit layer; etching a first type metal layer to form a second conductive circuit layer, the first conductive circuit layer and the second conductive circuit layer defining an inner circuit laminated structure; removing the dry film layer; and forming a first adding-layer circuit base board and a second adding-layer circuit base board on two surfaces of the inner laminated structure.

A wiring substrate includes: an insulating substrate being shaped in a quadrangle in a plan view, including a mounting portion where an electronic component is mounted on a side of a principal surface of the insulating substrate, and having a recess on a side surface thereof; an inner surface electrode which is located on an inner surface of the recess; a via conductor which is located on a corner side of the insulating substrate in a perspective plan view and has both ends located in a thickness direction of the insulating substrate; and a wiring conductor, on the side of the principal surface of the insulating substrate, connecting the mounting portion, the inner surface electrode, and the via conductor, wherein, in a perspective plan view, the wiring conductor has a wiring conductor absent region which surrounds a region located between the mounting portion and the via conductor.

A printed wiring board includes a base material, a plurality of electrode pads to which an electronic component is soldered, the electrode pads being formed on a surface of the base material, a molten-solder introducing protrusion formed on the surface of the base material and connected to each of the electrode pads to draw molten solder into the electrode pad during soldering, and a molten-solder separating protrusion formed on the surface of the base material and connected to each of the electrode pads to help separation of molten solder from the electrode pad at a moment of separation of molten solder, wherein the molten-solder introducing protrusion, the electrode pad, and the molten-solder separating protrusion are aligned in line.

A printed circuit board includes: a first insulating layer; a first circuit layer disposed on one surface of the first insulating layer; a second insulating layer disposed on the first insulating layer and covering at least a portion of the first circuit layer; a via conductor passing through the second insulating layer and connected to the first circuit layer; a via land connected to the via conductor in an upper portion of the via conductor; and a second circuit layer disposed on the second insulating layer and connected to the via land. The via conductor and the via land have a first interface where the via conductor and the via land are in contact with each other.

A multilayer printed circuit board providing large current and high power includes an inner circuit laminated structure, a first adding-layer circuit base board, and second adding-layer circuit base board. The inner circuit laminated structure includes at least one first type and second type conductive circuit layer alternately stacked. The first and second type conductive circuit layer are respectively made of first and second type metal layer, the first and second type metal layer have different etching ability. The second adding-layer circuit base board and the first adding-layer circuit base board are formed on opposite surfaces of the inner circuit laminated structure. The first and second adding-layer circuit base boards are electrically connected to the inner circuit laminated structure. The disclosure also provides a method for manufacturing such multilayer printed circuit board.

A circuit board includes a board body and pair of connection portions disposed at both ends of the board body. Each of the pair of connection portions is inserted into a connector. Each of the pair of connection portions includes a connection terminal electrically connected to the connector, and at least one of the pair of connection portions includes an extending portion extending from the connection terminal to an insertion leading end of the at least one of the pair of connection portion. The extending portion is disposed at a position to avoid a virtual line extending in an insertion direction through a position where the connector and the connection terminal are electrically connected.