A flexible printed circuit board with multiple layers includes an inner wiring substrate and at least one outer wiring plate. Each outer wiring plate is connected to one surface of the inner wiring substrate, and defines at least one through hole which passes through the outer wiring plate to expose the inner wiring substrate. Each outer wiring plate further includes an adhesive plate connected to the inner wiring substrate. The adhesive plate includes a stepped portion extending towards a center of the through hole.

A method for producing a package substrate for mounting a semiconductor device includes:

forming a first substrate by forming a laminate in which a first metal layer that has a thickness of 1 μm to 70 μm and that is peelable from a core resin layer, a first insulating resin layer, and a second metal layer are arranged on both sides of the core resin layer having a thickness of 1 μm to 80 μm, and heating and pressurizing the laminate simultaneously;

forming a pattern on the second metal layer;

forming a second substrate by heating and pressurizing a laminate formed by arranging a second insulating resin layer and a third metal layer on a surface of the second metal layer; and

peeling, from the core resin layer, a third substrate including the first metal and insulating resin layers, the second metal and insulating layers, and the third metal layer.

A circuit board with reduced dielectric losses enabling the movement of high frequency signals includes an inner circuit board and two outer circuit boards. The inner circuit board includes a first conductor layer and a first substrate layer. The first conductor layer includes a signal line and two ground lines on both sides of the signal line. The first substrate layer covers a side of the first conductor layer and defines first through holes which expose the signal line. Each outer circuit board includes a second substrate layer and a second conductor layer. The second substrate layer abuts the inner circuit board and defines second through holes which are not aligned with the first through holes, partially surrounding the signal line with air which has a very low dielectric constant. A method for manufacturing the high-frequency circuit board is also disclosed.

[Problem to be Solved]

A multilayer flexible printed circuit board having a strip line advantageous to folding is provided.

[Solution]

A multilayer flexible printed circuit board 100 of an embodiment is a multilayer flexible printed circuit board having a strip line foldable at a folding part F1, the board including: a flexible insulative substrate 30; an inner layer circuit pattern 5 provided inside the flexible insulative substrate 30 and including a signal line 6 extending in a predetermined direction; a ground thin film 14a constituting a ground layer at least in the folding part F1 out of a ground layer of the strip line and constituted of a nonelectrolytic plating coat 14 formed on the flexible insulative substrate 30; and a protective layer 20 that covers the ground thin film 14a and is in close contact with an exposed part 19 from which the flexible insulative substrate 30 is exposed.

A composite structure for use as a constituent of a mounting device, wherein the composite structure comprises an electrically conductive carrier, an intermediate layer comprising adhesion promoting material and being arranged on the electrically conductive carrier, and a thermally conductive and electrically insulating layer on the intermediate layer.

A printed circuit board package structure includes a substrate, plural ring-shaped magnetic elements, a support layer, and first conductive layers. The substrate has two opposite first and second surfaces, first ring-shaped recesses, and first grooves. Each of the first ring-shaped recesses is communicated with another first ring-shaped recess through at least one of the first grooves, and at least two of the first ring-shaped recesses are communicated with a side surface of the substrate through the first grooves to form at least two openings. The ring-shaped magnetic elements are respectively located in the first ring-shaped recesses. The support layer is located on the first surface, and covers the first ring-shaped recesses and the first grooves. The support layer and the substrate have through holes. The first conductive layers are respectively located on surfaces of support layer and substrate facing the through holes.

A wiring board includes a first electrically-conductive layer; and a first resin layer covering the first electrically-conductive layer, the first resin layer including a resin portion and inorganic insulating particles dispersed in the resin portion. The first resin layer has a first layer region which is in contact with one main surface and side surfaces of the first electrically-conductive layer, and a second layer region which is located on a side of the first layer region which side is opposite to the first electrically-conductive layer. The inorganic insulating particles include a plurality of first inorganic insulating particles contained in the first layer region, and a plurality of second inorganic insulating particles contained in the second layer region. A content rate of the first inorganic insulating particles in the first layer region is lower than a content rate of the second inorganic insulating particles in the second layer region.

A circuit board with reduced dielectric losses enabling the movement of high frequency signals includes an inner circuit board and two outer circuit boards. The inner circuit board includes a first conductor layer and a first substrate layer. The first conductor layer includes a signal line and two ground lines on both sides of the signal line. The first substrate layer covers a side of the first conductor layer and defines first through holes which expose the signal line. Each outer circuit board includes a second substrate layer and a second conductor layer. The second substrate layer abuts the inner circuit board and defines second through holes which are not aligned with the first through holes, partially surrounding the signal line with air which has a very low dielectric constant. A method for manufacturing the high-frequency circuit board is also disclosed.

One aspect of the present invention relates to a resin composition containing a polyrotaxane (A), an epoxy resin (B), and a curing agent (C), in which the curing agent (C) contains an acid anhydride (C-1) in an amount of 0.1 parts by mass or more and less than 10 parts by mass based on a total of 100 parts by mass of the polyrotaxane (A), the epoxy resin (B), and the curing agent (C).

The present invention relates to a resin composition comprising a maleimide compound having a saturated or unsaturated divalent hydrocarbon group and a divalent group having at least two imido bonds; and a catalyst comprising at least one selected from the group consisting of an imidazole compound, a phosphorus compound, an azo compound and an organic peroxide.