Provided is a method for forming a through-hole including: forming a laminated body including a fluororesin layer having a first main surface and a second main surface, a first adhesive layer, a first reinforcing resin layer and a first conductor layer provided on the first main surface, a second adhesive layer, a second reinforcing resin layer and a second conductor layer provided on the second main surface; forming an opening in the first conductor layer and irradiating the opening with a laser beam to form a bottomed conduction hole with the second conductor layer exposed on a bottom surface of the conduction hole, wherein a thermal decomposition temperature of the second cured adhesive layer is lower than those of the first reinforcing resin layer and the second reinforcing resin layer, and a thickness of the second cured adhesive layer is 10 μm or more and 200 μm or less.

A circuit board and a method of manufacturing the same are provided. The method includes the following steps of providing a first conductive layer; providing an adhesive material and at least one conductive bump, in which the adhesive material is electrically conductive; adhering at least one conductive bump to a surface of the first conductive layer using the adhesive material; providing an insulation layer; disposing the insulation layer on the surface of the first conductive layer and at least one conductive bump; and disposing a second conductive layer on the insulation layer.

A circuit board includes at least two circuit board units stacked together. Each circuit board unit includes a substrate and a circuit layer. The substrate defines a conductive hole penetrating therethrough. The conductive hole provided with a conductor therein. One side of the substrate further defines a groove, the groove including a concave portion aligned with the conductive hole. The circuit layer includes a connection pad located in the concave portion. The connection pad is shaped as a conductive protrusion, which surrounds and is electrically connected to the conductor. The circuit layer is located in the groove, and the conductive hole is electrically connecting the circuit layers of the circuit board units.

A multilayer resin substrate includes a base material including stacked resin layers including an opening resin layer, a conductor pattern, and an interlayer connection conductor. A concave portion is provided in the base material. The opening resin layer is closer to a first main surface than other resin layers. The concave portion includes a first opening portion provided by a cutting process from one surface of the opening resin layer, and another resin layer. The interlayer connection conductor is provided by filling a conductor in a second opening portion provided by a cutting process from an opposite surface of the opening resin layer. The end portion of the one surface of the first opening portion is not in contact with the conductor pattern.

Provided are a multilayer board and a method for manufacturing same, in which a different kind of metal layer is formed between an upper metal layer and an interlayer insulating layer, the different kind of metal layer being formed only in a wiring area without being formed in a via area. The multilayer board comprises: a substrate layer; a plurality of first metal layers sequentially stacked on the substrate layer; an interlayer insulating layer formed between two different first metal layers, having a first via hole, and electrically connecting the two different first metal layers through a third metal layer formed in the first via hole; and a second metal layer formed between the upper layer of the two different first metal layers and the interlayer 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 substrate bonding structure includes a first substrate including a first resin substrate that melts by heating, a second substrate having a second resin substrate that melts by heating, and an overlapping portion with the first substrate. The overlapping portion between the first substrate and the second substrate includes a hole continuously extending from the first substrate to the second substrate. The first substrate includes a melted portion of the first resin substrate around the hole, and the second substrate includes a melted portion of the second resin substrate around the hole. The first substrate and the second substrate are bonded to each other with a fused portion between the melted portion of the first resin substrate and the melted of the second resin substrate.

An electronic component embedded substrate includes a core structure including a first insulating body and core wiring layers and having a cavity and a stopper layer. An electronic component is disposed in the cavity. The stopper layer includes a first metal layer embedded in the first insulating body and having a portion of an inner surface exposed from the first insulating body, and a second metal layer disposed below the first metal layer and having at least a portion of an upper surface disposed as a bottom surface of the cavity. The cavity has an inner surface of the first metal layer and an inner surface of the first insulating body as a first wall surface and a second wall surface, respectively, and an inclination of the first wall surface is different from an inclination of the second wall surface.

The disclosure provides a method for manufacturing a circuit board, which includes: (1) providing a substrate, forming a through hole in the substrate; (2) filling the through hole with a conductor to form a conductive hole; (3) providing a peelable film to cover the substrate; (4) forming a groove by laser, the groove including a concave portion; (5) performing a surface treatment on a wall of the groove; (6) removing the peelable film; (7) forming a seed layer; (8) making a circuit layer to obtain a circuit board unit, the circuit layer including a connection pad, the connection pad shaped as a conductive protrusion which surrounds and is electrically connected to the conductor; (9) repeating step (1) to step (8) at least once; and (10) laminating the circuit board units. The disclosure also provides a circuit board.

A method of manufacturing a component carrier is disclosed. The method includes providing a stack having at least one electrically conductive layer structure and/or at least one electrically insulating layer structure, embedding a component in the stack, drilling a blind hole in the stack towards the embedded component, and thereafter extending the blind hole by etching to thereby expose a surface portion of the embedded component.