A circuit board comprises a row of solder pads adapted to be soldered to a row of contacts of a connector, a plurality of first conductive vias, and a plurality of second conductive vias. The contacts include a plurality of ground contacts and a plurality of signal contacts. The solder pads include a plurality of ground solder pads each soldered to a solder foot of one of the ground contacts and a plurality of signal solder pads each soldered to a solder foot of one of the signal contacts. The first conductive vias correspond to and are electrically connected to the ground solder pads and are electrically connected to each other by a first connection bar. The second conductive vias correspond to and are electrically connected to the ground solder pads and are electrically connected to each other by a second connection bar. The solder foot of each of the ground contacts is disposed between one of the first conductive vias and one of the second conductive vias.

A light emitting device and a keyboard structure are provided. The light emitting device includes a circuit board and multiple light emitting units. The circuit board includes a substrate, a first conductive pad, multiple second conductive pads, and multiple third conductive pads. The first conductive pad and the second conductive pads are disposed on a first board surface of the substrate. The first conductive pad has a symmetrical shape and a symmetrical axis. The symmetrical axis passes through the second conductive pads. The third conductive pads are disposed on a second board surface of the substrate. Each of the third conductive pads is electrically coupled to the first conductive pad and the second conductive pads by multiple conductive columns. Each of the light emitting units is connected to the first conductive pad and one of the second conductive pads.

The present disclosure provides a flexible circuit board, a light bar, a light source and a display device. The light source includes a flexible circuit board having at least one effective welding portion and a light bar having at least one effective pad, the at least one effective welding portion being in one-to-one correspondence with the at least one effective pad, and the effective welding portion being fixed to a corresponding effective pad to transmit a signal loaded by itself to the corresponding effective pad. The flexible circuit board further includes at least one auxiliary welding portion, the light bar further includes at least one auxiliary pad that is in one-to-one correspondence with the at least one auxiliary welding portion, and the auxiliary welding portion is fixed to a corresponding auxiliary pad to enhance the firm fixing between the flexible circuit board and the light bar.

An electronic device includes a housing, a circuit board disposed within the housing, a first component and a second component disposed on one surface of the circuit board, a shielding mold disposed on the one surface of the circuit board to cover top and side surfaces of the first component, and an open structure disposed on the one surface of the circuit board to surround a side surface of the second component. In the open structure, a top portion is opened and exposes a part of the second component or the circuit board, an inner surface is spaced apart from the second component, and an outer surface contacts the shielding mold.

In a flexible printed wiring board (1), a first electrical conduction pattern (4) prepared on the first surface (3a) on which a bare chip (2) is mounted is prepared only inside a mounting region (3c) of the bare chip. Preferably, the first electrical conduction patterns (4) are prepared so as to avoid positions opposite to test electrodes (2b) which the bare chip comprises. Thereby, in the flexible printed wiring board used for mounting the bare chip, occurrence of malfunction resulting from electrical connection with a part other than a bump of the bare chip can be certainly prevented, and reliability of various devices using the bare chip can be improved.

An electronic component is mounted on the mounting face of a printed wiring board and a plurality of terminals arranged on the mounting face of the printed wiring board are respectively bonded to a plurality of terminals arranged on the bottom surface of the electronic component by means of solder. Solder paste containing powdery solder and thermosetting resin is provided to the plurality of terminals on the mounting face, then the electronic component is mounted on the mounting face of the printed wiring board, and subsequently the solder paste is heated to bond the corresponding terminals by means of molten solder. Thereafter, the molten solder is allowed to solidify and the thermosetting resin separated from the solder paste is allowed to cure in a state where it is held in contact with metal members arranged separately relative to the terminals.

The present disclosure provides a flexible circuit board, a light bar, a light source and a display device. The light source includes a flexible circuit board having at least one effective welding portion and a light bar having at least one effective pad, the at least one effective welding portion being in one-to-one correspondence with the at least one effective pad, and the effective welding portion being fixed to a corresponding effective pad to transmit a signal loaded by itself to the corresponding effective pad. The flexible circuit board further includes at least one auxiliary welding portion, the light bar further includes at least one auxiliary pad that is in one-to-one correspondence with the at least one auxiliary welding portion, and the auxiliary welding portion is fixed to a corresponding auxiliary pad to enhance the firm fixing between the flexible circuit board and the light bar.

A printed wiring board includes a base insulating layer, a conductor layer including first and second pads, a solder resist layer covering the conductor layer and having first opening exposing the first pad and second opening exposing the second pad, a first bump including base plating layer in the first opening and top plating layer on the first base layer, and a second bump including base plating layer in the second opening and top plating layer on the base layer. The second opening has smaller diameter than the first opening, and the second bump has smaller diameter than the first bump. The first base layer has flat upper surface or first recess having depth of 20 m or less in upper central portion. The second base layer has flat upper surface, raised portion in upper central portion, or second recess shallower than the first recess in the upper central portion.

A printed-wiring board has a land group with which a terminal group of a semiconductor package has been joined, a first conductor pattern arranged in a mounting area where the semiconductor package is mounted and joined with a heat radiation plate of the semiconductor package, a second conductor pattern, at least a part of which is arranged on the outside of the mounting area, and a third conductor pattern which connects the first and second conductor patterns. The land group includes a first land adjacent to the third conductor pattern and a second land which is not adjacent to the third conductor pattern, and the first land is formed in a shape different from that of the second land so as to be away from the third conductor pattern.

A circuit board comprises a row of solder pads adapted to be soldered to a row of contacts of a connector, a plurality of first conductive vias, and a plurality of second conductive vias. The contacts include a plurality of ground contacts and a plurality of signal contacts. The solder pads include a plurality of ground solder pads each soldered to a solder foot of one of the ground contacts and a plurality of signal solder pads each soldered to a solder foot of one of the signal contacts. The first conductive vias correspond to and are electrically connected to the ground solder pads and are electrically connected to each other by a first connection bar. The second conductive vias correspond to and are electrically connected to the ground solder pads and are electrically connected to each other by a second connection bar. The solder foot of each of the ground contacts is disposed between one of the first conductive vias and one of the second conductive vias.