An electronic module includes a plurality of loads, a first wiring portion, a second wiring portion, a power source unit, and a feedback portion. The first wiring portion includes a plurality of first portions to which the plurality of loads are respectively connected, and a plurality of second portions each closest to a corresponding one of the plurality of first portions. The second wiring portion is connected to the plurality of second portions. The power source unit includes a feedback terminal, an output terminal, and a power source circuit. In the first wiring portion, a minimum path length from each of the plurality of second portions to the corresponding one of the plurality of first portions is smaller than 1/2 of a minimum path length from a part of the first wiring portion connected to the output terminal to the corresponding one of the plurality of first portions.

The present disclosure provides a method for manufacturing a board-to-board connection structure. The method includes defining a first through hole in a first circuit board, disposing a first connector within the first through hole by a first conductive paste, and connecting the first connector to a second circuit board on which a second connector is installed, thereby realizing a connection of the two circuit boards, and reducing a height of the two circuit boards after the connection. That is, the height of the board-to-board connection structure is reduced. Additionally, since the first connector is received within the first through hole, the first connector is not easy to be damaged and oxidized. The present disclosure further provides a board-to-board connection structure manufactured by the above method.

Disclosed is a copper foil including a copper layer and having a tensile strength of 29 to 65 kgf/mm.sup.2, a mean width of roughness profile elements (Rsm) of 18 to 148 m and a texture coefficient bias [TCB(220)] of 0.52 or less.

Film for use in preparing a printed circuit board (PCB) along with methods for making a PCB and producing a printable film are described herein. The film includes a first layer formed of a radiation-transparent material, a second layer formed of a curable adhesive material, a third layer formed of an electrically conductive material, and optionally, a fourth layer formed of an adhesive and a fifth layer formed of a removable material. Through the adhesive layers, the layers are bonded together to produce the printable film. To produce a PCB, the first layer is covered in ink distributed in a pattern representing the PCB, and the ink-covered film is exposed to radiation until the non-ink-covered portions of the second layer have cured. Then, the fifth layer is removed tearing away the electrically conductive material associated with the non-ink-covered portions of the second layer producing the PCB.

In a mark forming step in a manufacturing method for a component incorporated substrate in which an electronic component is positioned with reference to a mark formed in a copper layer, when an imaginary line extending from a search center of a search range of a sensor, to an edge side of the search range is represented as a search reference line and an imaginary line extending, in a state in which a mark center, is matched with the search center, from the mark center in the same direction as the search reference line to an outer ridgeline of the mark is represented as a mark reference line, the mark formed in a shape in which the outer ridgeline of the mark is present in a position where a length of the mark reference line is in a range of 30% or more of the search reference line.

A printed wiring board includes a multilayer core substrate, a first buildup layer formed on the multilayer core substrate and including an interlayer insulation layer and a conductive layer, a second buildup layer formed on the multilayer core substrate and including an interlayer resin insulation layer and a conductive layer, and an end-surface through hole conductor formed on side surfaces of the first and second buildup layers and core substrate such that the through hole conductor connects the conductive layers of the first and second buildup layers. The core substrate includes a first conductive layer, a middle conductive layer, a second conductive layer, a first insulation layer between the first and middle conductive layers and a second insulation layer between the second and middle conductive layers, and the middle conductive layer is connected to the through-hole conductor and has thickness greater than thicknesses of the first and second conductive layers.

A surface treated copper foil for a High-Frequency circuit as well as a corresponding method of treating a copper foil, the copper foil including two opposite sides, where a first side is coated with a treatment layer including, in this order: a first layer including oxides of Mo and of Zn deposited on the first side, where the first layer is free of Ni; a second layer of Cr oxide; and a coupling agent layer; where the first layer includes the oxides of Mo and of Zn in a quantity of between 5 and 30 mg/m.sup.2 calculated as Mo and Zn; where the treatment layer has a roughness Rz JIS of 0.7 m or less; and where the first side is free of roughening treatment.

When a laminate of a plurality of different materials including a metal plate is bonded in a pressurized and heated state, a first pressurizing member in which a first metal foil/a carbon sheet or a ceramic sheet/a graphite sheet are laminated in this order is arranged so that the first metal foil is in contact with a surface of the first metal plate of the laminate, the first metal foil is made of a material that does not react at a contact surface of the first plate member and the first metal foil when heating, and a product of a Young's modulus (GPa) and a thickness (mm) of the first metal foil is 0.6 or more and 100 or less, so that a good bonded body can be manufactured by evenly pressurizing the laminate and foreign substances can be restrained from adhering to the surface of the laminate.

A wiring board according to the present disclosure includes a first insulation layer including a first surface, and an electrical conductor layer located on the first surface. The first insulation layer includes an insulating resin, and a plurality of insulating particles dispersed in the insulating resin. The plurality of insulating particles include a first insulating particle including a first region exposed from the insulating resin on the first surface and a second region other than the first region when the first surface is viewed in a top surface view. The electrical conductor layer is located on a surface of the first region and a surface of the insulating resin and is not located below the first region and between the second region and the insulating resin.

A voltage converter is provided, comprising: a first circuit board with a first circuit section of the voltage converter, wherein the first circuit section comprises semiconductor chips embedded between metal layers of the first circuit board, and a second circuit section a second circuit board with a second circuit section of the voltage converter, wherein the first circuit section is electrically coupled to the second circuit section.