A metal-clad laminate according to the present embodiment includes an insulating layer, and a metal layer present on at least one surface side of the insulating layer. The insulating layer is a laminate of at least three layers of a center layer, a first resin layer present on one surface side of the center layer, and a second resin layer present on the other surface side of the center layer. The center layer, the first resin layer and the second resin layer each contain a cured product of a resin composition. Coefficients of thermal expansion of the cured products of the resin compositions contained in the first resin layer and the second resin layer are smaller than a coefficient of thermal expansion of the cured product of the resin composition contained in the center layer.

A metal-clad laminate according to the present embodiment includes an insulating layer, and a metal layer present on at least one surface side of the insulating layer. The insulating layer is a laminate of at least three layers of a center layer, a first resin layer present on one surface side of the center layer, and a second resin layer present on the other surface side of the center layer. The center layer, the first resin layer and the second resin layer each contain a cured product of a resin composition. Coefficients of thermal expansion of the cured products of the resin compositions contained in the first resin layer and the second resin layer are smaller than a coefficient of thermal expansion of the cured product of the resin composition contained in the center layer.

A metal-clad laminate according to the present embodiment includes an insulating layer, and a metal layer present on at least one surface side of the insulating layer. The insulating layer is a laminate of at least three layers of a center layer, a first resin layer present on one surface side of the center layer, and a second resin layer present on the other surface side of the center layer. The center layer, the first resin layer and the second resin layer each contain a cured product of a resin composition. Coefficients of thermal expansion of the cured products of the resin compositions contained in the first resin layer and the second resin layer are smaller than a coefficient of thermal expansion of the cured product of the resin composition contained in the center layer.

A method of manufacturing a patterned conductor is provided, comprising: providing a substrate, comprising: a base material with an electrically conductive layer disposed thereon; providing an electrically conductive layer etchant; providing a spinning material, comprising: a carrier; and, a photosensitive masking material; providing a developer; forming a plurality of masking fibers and depositing them onto the electrically conductive layer to form a plurality of deposited fibers; patterning the plurality of deposited fibers to provide a treated fiber portion and an untreated fiber portion; developing the plurality of deposited fibers, wherein either the treated fiber portion or the untreated fiber portion is removed, leaving a patterned fiber array; contacting the electrically conductive layer to the electrically conductive layer etchant, wherein the electrically conductive layer that is uncovered by the patterned fiber array is removed, leaving a patterned conductive network on the substrate.

A conductive pattern formation method of the present invention includes a first exposure step of radiating active light in a patterned manner to a photosensitive layer including a photosensitive resin layer provided on a substrate and a conductive film provided on a surface of the photosensitive resin layer on a side opposite to the substrate; a second exposure step of radiating active light, in the presence of oxygen, to some or all of the portions of the photosensitive layer not exposed at least in the first exposure step; and a development step of developing the photosensitive layer to form a conductive pattern following the second exposure step.

A stacked semiconductor package includes a first semiconductor package including a first circuit board and a first semiconductor device mounted on the first circuit board; a second semiconductor package including a second circuit board and a second semiconductor device mounted on the second circuit board, the second semiconductor package being stacked on the first semiconductor package; and a heat transfer member provided on the first semiconductor device and a part of the first circuit board, the part being around the first semiconductor device.

There are provided a laminate and the like and a circuit board including the same that exhibit an excellent low dielectric property by a non-conventional new approach. The laminate according to an embodiment of the present invention is a laminate used for a core layer of a circuit board, in which the laminate does not include a buildup layer, the laminate is obtained by laminating a plurality of prepregs including a fiber base material layer and a resin layer (A) so that the prepregs are in direct contact with each other, the resin layer (A) contains an inorganic filler and hollow resin particles, and the hollow resin particles are contained in the resin layer (A) in an amount of 1% by weight to 50% by weight with respect to the total amount of the resin layer (A).

An electronic component mounting substrate includes an electronic component, a printed wiring board that mounts the electronic component thereon, and a cover that accommodates and seals the electronic component mounted on the printed wiring board. The cover has an upper portion and a support portion supporting the upper portion such that the upper portion has a thickness of 2 mm or more, and the printed wiring board includes an upper build-up part and a lower build-up part such that the upper build-up part mounts the electronic component thereon and includes an uppermost resin insulating layer not containing a reinforcing material and that the lower build-up part includes a lowermost resin insulating layer including a reinforcing material.

A circuit board according to an embodiment includes an insulating layer; and a via portion disposed in a via hole formed in the insulating layer; wherein the via portion includes: a first pad disposed on a lower surface of the insulating layer; a second pad disposed on an upper surface of the insulating layer; a third pad disposed in the via hole and disposed on the first pad; and a connection portion disposed in the via hole and disposed between the second pad and the third pad.

In a radio frequency module, a resin layer is disposed on a first main surface of a mounting substrate and covers electronic components. An external shield layer covers at least part of an outer peripheral surface of the mounting substrate and the resin layer. The mounting substrate includes a first dielectric layer, a second dielectric layer, and ground electrodes. The first dielectric layer contains a resin and does not contain a glass fiber. The second dielectric layer overlaps the first dielectric layer in a thickness direction of the mounting substrate and is in contact with the first dielectric layer. The second dielectric layer contains a resin and does not contain a glass fiber. The ground electrodes are interposed between the first dielectric layer and the second dielectric layer. The ground electrodes are each directly connected to the external shield layer.