A control circuit board includes first and second elements on each surface of a board member. The first and the second elements respectively have first and third edge portions, which are opposite to each other and second and fourth edge portions which are opposite to each other. A plurality of signal input pins are provided to the first edge portion, a plurality of signal output pins are provided to the third edge portion, a plurality of between-element communication input pins are provided to the second edge portion, and a plurality of between-element communication output pins are provided to the fourth edge portion, respectively. A common signal is input to the first and second elements and a communication is performed between the first element and the second element. Loss of control function can be surely prevented while suppressing enlargement of the board and increase of development/production cost.

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.

A stretchable mounting board that includes a mounting electrode section electrically connected to stretchable wiring, and solder electrically connected to the mounting electrode section. The mounting electrode section has a first electrode layer on a side thereof facing the stretchable wiring and which includes bismuth and tin, and a second electrode layer on a side thereof facing the solder and which includes bismuth and tin. A concentration of the bismuth in the first electrode layer is lower than a concentration of the bismuth in the second electrode layer, and the concentration of the bismuth in the second electrode layer is constant along a thickness direction thereof.

A circuit structure includes a first busbar, a second busbar, an insulating member including an insulating portion located between the first busbar and the second busbar, a first wiring board provided on one main surface of the first busbar, one main surface of the second busbar and the insulating portion, and a first electronic component provided on the first wiring board. The first electronic component has a first connection terminal electrically connected to the first busbar and bonded to the first wiring board, and a second connection terminal electrically connected to the second busbar and bonded to the first wiring board.

A wiring board includes a first insulating layer, a pad formed on one surface of the first insulating layer, a second insulating layer, formed on the one surface of the first insulating layer, and including an opening exposing the pad, and a reinforcing metal layer formed in contact with the first insulating layer, and provided around the pad so as to be separated from the pad in a plan view. The pad is disposed inside the opening without making contact with the second insulating layer. An end, on a side of the first insulating layer, in a portion of an inner side surface of the opening of the second insulating layer makes contact with the reinforcing metal layer, and an end in another portion of the inner side surface of the opening of the second insulating layer makes contact with the one surface of the first insulating layer.

A flexible printed circuit board with improved ground efficiency is disclosed, and a flexible display module and an electronic device comprising the same is disclosed, wherein the flexible printed circuit board comprises a flexible circuit film having a circuit layer disposed on one surface of a base film, and a ground pad portion disposed on another surface of the base film; and a conductive cover member configured to cover the other surface of the base film and electrically connected with the ground pad portion, wherein the conductive cover member includes a cutting portion overlapped with the ground pad portion.

An electronic component includes: an insulating layer; and a first metal bump disposed on the insulating layer and provided with: a first metal layer disposed on the insulating layer; and a second metal layer disposed on the first metal layer, wherein, in a cross-sectional view of the electronic component, the first metal layer has a first width, the second metal layer has a second width, and the first width is smaller than the second width.

An object of the present invention is to provide an electronic control device capable of improving the connection life and reliability of solder connecting a printed circuit board and a QFN type semiconductor package. For this purpose, a printed circuit board 106 includes a first land 109 connected to a first metal terminal 104 via a solder 107, a second land 110 connected to a second metal terminal 105 via a solder 108, a third land 112 disposed on the outer peripheral side of a semiconductor package 101 with respect to the first land 109, and a resist 113 formed on the third land 112 so as to be in contact with the lower surface of a molding resin 103.

A circuit board is disclosed, including a circuit board body and at least one via apparatus provided on the circuit board body. The via apparatus includes a via (101) formed on the circuit board body, a via pad (201) surrounding the via and separately provided from the via, and an electrical conductor (301) electrically connecting the via pad (201) with the via (101).

A stretchable mounting board that includes a stretchable substrate having a main surface, a stretchable wiring disposed on the main surface of the stretchable substrate, a mounting electrode section electrically connected to the stretchable wiring, solder electrically connected to the mounting electrode section and including bismuth and tin, and an electronic component electrically connected to the mounting electrode section with the solder interposed therebetween. The mounting electrode section has a first electrode layer on a side thereof facing the stretchable wiring and which includes bismuth and tin, and a second electrode layer on a side thereof facing the solder and which includes bismuth and tin. A concentration of the bismuth in the first electrode layer is lower than a concentration of the bismuth in the second electrode layer.