A method for designing PCB pads: using a drill bit of a first size to drill through a PCB from a first side; using a drill bit of a second size to back-drill a second side of the PCB so as to form a pyramid-shaped through hole; setting the connection means of a second layer and third layer of an inner layer of the PCB that comprises the pyramid-shaped through hole to full connection; and disposing a pad of a third size on a first layer of the inner layer, and disposing a pad of a fourth size on the last layer of the inner layer, wherein the fourth size is bigger than the third size, the fourth size is bigger than the second size, the second size is bigger than the first size, and the third size is bigger than the first size.

A board drilling apparatus, drill bit, and method for board drilling apparatus to drill a board. The board drilling apparatus (4) is configured to drill a board comprising at least a target conductive layer (13), an insulation layer, and a hole (3) covered with conductive material through at least part of the board in thickness, to remove at least part of the conductive material, the board drilling apparatus (4) comprising a drill bit (41) and a controller (43): the drill bit (41) comprising an insulation part (412) at least in center of end of the drill bit (41) and a conductive part (411) at least on edge of the end of the drill bit (41), arranged to enable only the insulation part (412) to be in touch with the conductive material of the hole (3) when the board drilling apparatus (4) is drilling the board, and arranged to enable the conductive part to get in touch with the target conductive layer (13) once the conductive material on the way to the target conductive layer (13) has just been removed; and the controller (43) configured to stop drilling when receiving an electrical signal occurred in response to the drill bit touching the target conductive layer of the board.

A method for manufacturing a circuit board including the following steps: providing a flexible double-sided metal-clad laminate including a first metal foil, a flexible dielectric layer, and a second metal foil. A carrier is attached to the second metal foil. A first wiring layer including a first wiring region and a second wiring region is formed by the first metal foil. The first wiring region includes a first connecting pad, and the second wiring region includes a connecting pad. A plurality of rigid dielectric blocks surrounded to form an interval and a first groove exposing the first connecting pad is pressed on the flexible dielectric layer to form a rigid dielectric layer. An electronic component is fixed the first groove. The carrier is removed. The intermediate structure is bent along the interval and pressed. A second wiring layer is formed by the second metal foil.

A circuit board may include a plurality of electrically-conductive layers separated and supported by layers of insulating material laminated together and a via electrically coupled to a first layer of the circuit board and coupled to a second layer of the circuit board, the via comprising a first via portion comprising electrically-conductive material and having a first diameter and a first depth from a surface of the circuit board and a second via portion comprising electrically-conductive material and having a second diameter smaller than the first diameter and a second depth from the first depth.

An electronic control device includes a board including a heat sink on which a heat generation element is mounted, and a housing that is in contact with the board and dissipates heat of the heat generation element to the outside. A potential of the housing is a ground, and a potential of the heat sink is a non-ground. The board includes a first layer including a first non-ground wiring that is in direct contact with the heat sink, and a second layer including a second ground wiring that is in electrical and thermal contact with the housing. The first non-ground wiring and the second ground wiring overlap each other in plan view from a thickness direction of the board.

A method for manufacturing a circuit board including the following steps: providing a flexible double-sided metal-clad laminate including a first metal foil, a flexible dielectric layer, and a second metal foil. A carrier is attached to the second metal foil. A first wiring layer including a first wiring region and a second wiring region is formed by the first metal foil. The first wiring region includes a first connecting pad, and the second wiring region includes a connecting pad. A plurality of rigid dielectric blocks surrounded to form an interval and a first groove exposing the first connecting pad is pressed on the flexible dielectric layer to form a rigid dielectric layer. An electronic component is fixed the first groove. The carrier is removed. The intermediate structure is bent along the interval and pressed. A second wiring layer is formed by the second metal foil.

A printed circuit board includes a plurality of layers including attachment layers and routing layers; and columns of via patterns formed in the plurality of layers, wherein via patterns in adjacent columns are offset in a direction of the columns, each of the via patterns comprising: first and second signal vias forming a differential signal pair, the first and second signal vias extending through at least the attachment layers; and at least one conductive shadow via located between the first and second signal vias of the differential pair. In some embodiments, at least one conductive shadow via is electrically connected to a conductive surface film.

An electronics module (100), especially a power electronics module, comprising a metal-ceramic substrate (1) serving as a carrier and having a ceramic element (10) and a primary component metallization (21), an insulation layer (40) directly or indirectly connected to the primary component metallization (21), and a secondary component metallization (22) which is connected to the side of the insulation layer (40) facing away from the metal-ceramic substrate (1) and is especially isolated from the primary component metallization (21) using the insulation layer (40), wherein the ceramic element (10) has a first size (L1, D1) and the insulation layer (40) has a second size (L2, D2) and a ratio of the second size (L2, D2) to the first size (L1, D1) has a value smaller than 0.8, to form an island-like insulation layer (40) on the primary component metallization (21).

A wiring board includes an insulating base having a first principal surface, and a second principal surface opposite to the first principal surface, a first through hole formed in the base, a first conductive layer provided inside the first through hole, a first insulating layer covering the first principal surface, a second insulating layer covering the second principal surface, a second through hole formed in the first insulating layer, the base, and the second insulating layer, a magnetic material provided inside the second through hole, a third through hole famed in the magnetic material, and a second conductive layer provided inside the third through hole.

A multilayer circuit board structure includes superconducting connections to internal layers thereof, for example by inclusion of superconducting vias. Two or more panels can each comprise respective electrically insulative substrates, each have one or more through-holes, and also include a respective bimetal foil on at least a portion of a respective surface thereof, which is patterned to form traces. The bimetal foil includes a first metal that is non-superconductive in a first temperature range and a second metal that is superconductive in the first temperature range. The panels are plated to deposit a third metal on exposed traces of the second metal, the third metal superconductive in the first temperature range. Panels are join (e.g., laminated) to form at least a three-layer superconducting printed circuit board with an inner layer, two outer layers, and superconducting vias between the inner layer and at least one of the two outer layers.