A wiring board includes a first wiring layer formed on one surface of a core layer, a first insulating layer formed on the one surface of the core layer so as to cover the first wiring layer, a via wiring embedded in the first insulating layer, a second wiring layer formed on a first surface of the first insulating layer, and a second insulating layer thinner than the first insulating layer formed on the first surface of the first insulating layer so as to cover the second wiring layer. The first wiring layer comprises a pad and a plane layer provided around the pad. One end surface of the via wiring is exposed from the first surface of the first insulating layer and directly bonded to the second wiring layer. The other end surface of the via wiring is directly bonded to the pad in the first insulating layer.

A manufacturing method for flexible printed circuit board is provided, in which a flexible insulating material and a metal material are liquefied and the liquefied materials are coated and solidified to form a flexible insulating layer and an anti-EMI layer of an anti-EMI structure, respectively. As such, an adhesive layer can be eliminated and the thickness of the flexible insulating layer and the anti-EMI layer can be reduced and an amount of materials consumed is also reduced, resulting in reduction of production cost, reduction of thickness of the flexible printed circuit board with anti-EMI structure, and improved quality.

A protection tape for a printed circuit board (PCB) includes an insulating base plate, a conductive layer over the insulating base plate, and an adhesive layer over the conductive layer, the adhesive layer including a main part having a first thickness and a subsidiary part having a second thickness less than the first thickness, the main part corresponding to at least a center portion of the insulating base plate and the subsidiary part being arranged at an outside of the main part.

Provided are a printed circuit board in which warps are effectively suppressed, and a semiconductor package having a semiconductor device mounted on said printed circuit board, even though circuit patterns of different amounts of metal are formed on both sides of one cured product of a prepreg. Specifically, said printed circuit board is a printed circuit board which comprises a cured product of a prepreg comprising a fiber base material and a resin composition, in which circuit patterns of different amounts of metal are formed on both sides of one cured product of the prepreg, in which said prepreg has layers on the front and back of said fiber base material, wherein said layers comprise resin compositions having different heat curing shrinkage rates, in which among these layers, the layer made of the resin composition having a smaller heat curing shrinkage rate is present on the side on which the circuit pattern with a smaller amount of metal is formed.

The present disclosure provides a conductor arrangement for transmitting differential communication signals, the conductor arrangement includes a conductor carrier, a plurality of pairs of first conductors, two of the first conductors being electrically coupled together at their ends, and a plurality of pairs of second conductors, two of the second conductors being electrically coupled together at their ends, and wherein, as conductor bundles, in each case one of the first conductors of a pair and one of the second conductors of a pair are jointly arranged on a first side of the conductor carrier and the further first conductor of the respective pair and the further second conductor of the respective pair are arranged on a second side of the conductor carrier.

A transmission line member includes a base body extending along a transmission direction of a high-frequency signal, and a first transmission line, a second transmission line, and a third transmission line. The base body includes a first portion including the first transmission line, a second portion including the second transmission line, and a third portion including the third transmission line. The second portion is connected between the first and third portions. A thickness of the second portion is smaller than a thickness of the first and third portions. The second transmission line includes only a conductor pattern extending more in the transmission direction than in a direction of the thickness.

A flexible circuit board including at least two electrical conducting layers, at least two non-electrical conducting layers, and at least one adhesion layer is provided. The non-electrical conducting layers are disposed between the electrical conducting layers. The non-electrical conducting layers are adhered together via the adhesion layer. A sum of thickness of the non-electrical conducting layers is greater than 4 mil, and there is no electrical conducting layer sandwiched between the at least two non-electrical conducting layers.

A wiring substrate includes a core substrate, and a build-up part laminated on the substrate and including resin insulating layers. The insulating layers include a first insulating layer, the build-up part includes a conductor layer on the first insulating layer, a second insulating layer on the first insulating layer and covering the conductor layer, and a recess penetrating through the second insulating layer and exposing portion of the conductor layer such that the conductor layer includes component mounting region that places an electronic component in the recess and a conductor pad forming bottom surface of the recess, the insulating layers include inorganic filler such that all insulating layers or all insulating layers other than the first insulating layer include the inorganic filler and that inorganic filler content rate of the first insulating layer is lower than inorganic filler content rate of the insulating layers other than the first insulating layer.

Package to printed circuit board (PCB) transitions are described. In one aspect, a multi-layer PCB includes an external layer having a transition region configured to receive an electrical component and a clear routing region outside of the transition region. The PCB includes first via(s) that extend from the transition region to an inner trace routing layer. The trace routing layer is disposed between the external layer and the second inner trace routing layer. The first inner trace routing layer includes a transition area disposed under the transition region of the external layer, a clear routing area outside of the transition region, and a transmission line that connects a given first via to a second via for a second electrical component. The transmission line includes conductive trace(s) that each have a first width in the transition area and a second width, greater than the first width, in the clear routing area.

A flexible laminated sheet manufacturing method includes thermocompression-bonding an insulation film formed of a liquid crystal polymer onto a metal foil between endless belts to form a flexible laminated sheet. The thermocompression bonding includes heating the flexible laminated sheet so that the maximum temperature of the sheet is in the range from a temperature that is 45° C. lower than the melting point of the liquid crystal polymer to a temperature that is 5° C. lower than the melting point. The thermocompression bonding also includes slowly cooling the flexible laminated sheet so that an exit temperature, which is a temperature of the sheet when transferred out of the endless belts, is in the range from a temperature that is 235° C. lower than the melting point of the liquid crystal polymer to a temperature that is 100° C. lower than the melting point.