A method for manufacturing a wiring board includes preparing a core substrate having first and second surfaces, forming a first build-up structure including interlayer insulating layers and conductor layers on the first surface of the substrate, and forming a second build-up structure including interlayer insulating layers and one or more conductor layers on the second surface of the substrate. The forming of the first structure includes laminating the insulating layers and metal layers on first surface side of the substrate and forming the conductor layers from all of the metal layers on the first surface side, and the forming of the second structure includes laminating the insulating layers and metal layers on second surface side of the substrate, forming the one or more conductor layers from one or more of the metal layers on the second surface side, and entirely removing the other metal layers on the second surface side.

Provided is a glass cloth obtained by weaving a glass thread, which is made from a plurality of glass filaments, as a warp and weft. The average filament diameter of the glass filaments is 3.0-4.5 μm. The respective weaving densities of the warp and the weft constituting the glass cloth are, independently, 70-130 threads/25 mm. The standard deviation of weft width of the glass cloth is not more than 30 μm. The weft covering ratio R, which is represented by the expression R=Y/(25400/D) (where R is the weft covering ratio, Y is the average weft width, and D is the well weaving density) satisfies the relational expression 0.50≤R≤0.83.

A method of manufacturing a circuit board is provided. The method includes forming an open substrate, in which the open substrate includes a substrate body having a top surface and a bottom surface; an opening in the substrate body, in which the opening has a first sidewall and a second sidewall opposite to the first sidewall; and at least one first fixing portion and at least one second fixing portion extending from the substrate body toward the opening, in which the first fixing portion and the second fixing portion are respectively protruded from the first sidewall and the second sidewall. A heat dissipation block is inserted in the opening to clamp the heat dissipation block between the first fixing portion and the second fixing portion, in which the heat dissipation block includes the heat dissipation block comprises a ceramic or a composite material.

The present invention provides a novel method of constructing a coax spring-pin socket that furnishes better performance and is easier to manufacture in volume using common dielectrics and copper plating. This is accomplished by, in application, a lamination of PCB dielectric layers. This dielectric block is then drilled, plated, etched, and drilled in steps for the construction of a coaxial structure for the signal pins, and a ground structure for ground pins. This design process that can be quickly adjusted and customized for each design.

Provided is an entry sheet for drilling that, compared with a conventional entry sheet for drilling, has better hole position accuracy, can suppress drill bit breakage, and exhibits less processing chips wrapping around the drill bit. This entry sheet for drilling includes a metallic support foil and a layer comprising a resin composition that is formed on at least one surface of the metallic support foil, wherein the resin composition contains a cellulose derivative (A) and a water-soluble resin (B), the cellulose derivative (A) includes a hydroxyalkyl cellulose and/or a carboxyalkyl cellulose having a weight average molecular weight of 20,000 to 350,000, and based on 100 parts by mass of the resin composition, the content of the cellulose derivative (A) is 5 to 40 parts by mass and the content of the water-soluble resin (B) is 60 to 95 parts by mass.

A passive device packaging structure embedded in a glass medium according to an embodiment of the present disclosures includes a glass substrate and at least one capacitor embedded in the glass substrate. The capacitor includes an upper electrode, a dielectric layer, and a lower electrode. The glass substrate is provided on its upper surface with a cavity, the dielectric layer covers a surface of the cavity and has an area larger than that of the cavity. The upper electrode is provided on the dielectric layer. The dielectric layer and the lower electrode are connected by a metal via pillar passing through the glass substrate.

Back drilling vias of a PCB, including: identifying a particular diameter of a particular via of multiple vias of the PCB; back drilling of the particular via with a first drill bit having a first diameter, the first diameter a first percentage greater than the particular diameter of the particular via; determining whether the first diameter of the first drill bit is a threshold percentage greater than the particular diameter of the particular via; determining that the first diameter of the first drill bit is less than the threshold percentage greater than the particular diameter of the particular via, and in response: back drilling of the particular via with a second drill bit having a second diameter, the second diameter a second percentage greater than the particular diameter of the particular via, the second diameter greater than the first diameter.

A printed circuit board is provided. The board includes a plurality of vias through the printed circuit board, each having a first section with a first width, a second section with a second width less than the first width, and a third section with a third width greater than the second width and less than the first width. The second section is located between the first section and the third section, the first and second sections are plated, and the third section lacks plating. At least one of the plurality of vias has the first width dimensioned to receive a connector pin inserted through the first face. A further at least one of the plurality of vias has the first width dimensioned to receive a further connector pin inserted through the second face. Further versions of the printed circuit board and method of making a printed circuit board are provided.

A drill hole inspection method for using a drill hole inspection system to inspect a drill hole of a printed circuit board (PCB) is provided. The drill hole inspection method includes: scanning the PCB to obtain 3-dimensional (3D) image voxel data of the PCB; determining a first-dimension interval corresponding to the PCB along one direction of the 3D image voxel data; determining, in a plane of the 3D image voxel data which is orthogonal to the direction, a 2-dimensional (2D) position corresponding to the drill hole; extracting a portion of the 3D image voxel data as drill hole voxel data according to the first-dimension interval and the 2D position; analyzing the drill hole voxel data to obtain an inspection result of the drill hole; and outputting the inspection result through an output component. In addition, a drill hole inspection system and an inspection device using the same are also provided.

Provided is a landless multilayer circuit board and a manufacturing method thereof. The manufacturing method includes steps of forming a first circuit on a first substrate, patterning a photoresist layer to form at least one via between the first circuit and a second circuit, forming at least one connecting pillar in the at least one via, removing the photoresist layer, forming a second substrate to cover the at least one connect pillar, and forming the second circuit on the second substrate. The second circuit is connected to the first circuit through the at least one connecting pillar. When the second circuit is formed, the at least one via does not need to be filled, thereby making the second circuit flat.