A process for producing a backplane circuit board (20) having an internal face (142) adapted to be connected to connectors (13) of circuit boards (12) and an external face (143) adapted to be connected to an external connector (15), blind holes (146, 148) opening on the internal face (142) and external face (143) of the backplane circuit board (20), wherein bonding layers (31, 32) having zones (41, 42) cleared of material facing the blind holes are used between the printed circuits (21, 22, 23).

A flexible circuit board including: a body area including a plurality of wirings; a bonding area combined with a first side of the body area; and an extension area combined with a second side of the body area opposite to the first side. The body area includes a first sub-body area and a second sub-body area located on a side of the first sub-body area close to the extension area; the plurality of wirings at least include a first wiring, a second wiring and a third wiring all extend in the first sub-body area, and the first wiring and the second wiring extend in the second sub-body area. The first sub-body area includes a multi-layer board structure, the second sub-body area includes a single-layer board structure or a double-layer board structure, and a thickness of the second sub-body area is smaller than a thickness of the first sub-body area.

A circuit board includes a first dielectric material, a second dielectric material, a third dielectric material, a first external circuit layer, a second external circuit layer, multiple conductive structures, and a conductive via structure. Dielectric constants of the first, the second and the third dielectric materials are different. The first and the second external circuit layers are respectively disposed on the first and the third dielectric materials. The conductive via structure at least penetrates the first and the second dielectric materials and is electrically connected to the first and the second external circuit layers to define a signal path. The conductive structures are electrically connected to each other and surround the first, the second and the third dielectric materials. The conductive structures are electrically connected to the first and the second external circuit layers to define a ground path surrounding the signal path.

A circuit board includes a first external circuit layer, a first substrate, a second substrate, a third substrate, and a conductive through hole structure. The first substrate includes conductive pillars electrically connecting the first external circuit layer and the second substrate. The second substrate has an opening and includes a first dielectric layer. The opening penetrates the second substrate, and the first dielectric layer fills the opening. The third substrate includes an insulating layer, a second external circuit layer, and conductive holes. A conductive material layer of the conductive through hole structure covers an inner wall of a through hole and electrically connects the first and the second external circuit layers to define a signal path. The first external circuit layer, the conductive pillars, the second substrate, the conductive holes and the second external circuit layer are electrically connected to define a ground path surrounding the signal path.

A circuit board includes a first substrate, a second substrate, a third substrate, a plurality of conductive structures and a conductive via structure. The second substrate is disposed between the first substrate and the third substrate. The third substrate has an opening and includes a first dielectric layer, a second dielectric layer, and a third dielectric layer. The opening penetrates the first dielectric layer and the second dielectric layer, and the third dielectric layer fully fills the opening. The conductive via structure penetrates the first substrate, the second substrate, the third dielectric layer of the third substrate, and is electrically connected to the first substrate and the third substrate to define a signal path. The first substrate, the second substrate, and the third substrate are electrically connected through the conductive structures to define a ground path, and the ground path surrounds the signal path.

The present disclosure relates to a printed circuit board assembly including a first circuit board including a first footprint, the first circuit board further includes a plurality of first vertical vias extending between a first side and an opposing second side; a second circuit board including a second footprint smaller than the first footprint, the second circuit board further includes a plurality of second vertical vias extending between a subsequent first side and an opposing subsequent second side; an adhesive layer coupling the first side to the subsequent first side; and a plurality of third vertical vias extending through the first side and the subsequent first side.

A printed circuit board includes a first and second core. The first core has a first conductive layer, a first non-conductive layer, a first copper layer and a first opening. The first core also has a first solder mask connected to the first copper layer and a first FR4 laminate bonded to the first solder mask. The second core has a second conductive layer, a second non-conductive layer, a second copper layer and a second opening. The second core also has a second solder mask connected to the second copper layer and a second FR4 laminate bonded to the second solder mask. A prepreg layer is between the first copper layer and the second copper layer but not between the first FR4 laminate and the second FR4 laminate.

A method includes forming a first redistribution line, forming a polymer layer including a first portion encircling the first redistribution line and a second portion overlapping the first redistribution line, forming a pair of differential transmission lines over and contacting the polymer layer, and molding the pair of differential transmission lines in a molding compound. The molding compound includes a first portion encircling the pair of differential transmission lines, and a second portion overlapping the pair of differential transmission lines. An electrical connector is formed over and electrically coupling to the pair of differential transmission lines.

A semiconductor composite device is provided that includes a voltage regulator, a package board, and a load, and converts an input DC voltage into a different DC voltage to supply the converted DC voltage to the load. The VR includes a semiconductor active element. The package board includes a C layer in which a capacitor is formed, and an L layer in which an inductor is formed. A plurality of through holes penetrate the C layer and the L layer in a direction perpendicular to the mounting face in the package board. The capacitor is connected to the load through the through hole. The inductor is connected to the load through the through hole and to the VR through the through hole.

A process for producing a backplane circuit board (20) having an internal face (142) adapted to be connected to connectors (13) of circuit boards (12) and an external face (143) adapted to be connected to an external connector (15), blind holes (146, 148) opening on the internal face (142) and external face (143) of the backplane circuit board (20), wherein bonding layers (31, 32) having zones (41, 42) cleared of material facing the blind holes are used between the printed circuits (21, 22, 23).