A method of manufacturing a printed circuit board includes: forming first and second resist films, respectively having first and second openings exposing a first metal layer disposed on one surface of an insulating layer; forming a second metal layer on the first metal layer, exposed through the first and second openings, to fill at least a portion of each of the first and second openings; and removing the first and second resist films. The first and second openings have different widths in a cross-section.

A wiring substrate includes a core substrate including a core insulating layer, a first conductor layer, a second conductor layer, a first insulating layer, a second insulating layer, a third conductor layer, and a fourth conductor layer. The first conductor layer includes first land and first plane parts, the second conductor layer includes second land and second plane parts, the third conductor layer includes fine wirings and a third plane part, the fourth conductor layer includes fine wirings and a fourth plane part, the substrate includes a through-hole conductor connecting the first and second land parts through the core insulating layer, a first via conductor connecting the first land part and third conductor layer, a second via conductor connecting the second land part and fourth conductor layer, a third via conductor connecting the first and third plane parts, and a fourth via conductor connecting the second and fourth plane parts.

A circuit structure that comprises a substrate and one or more conductive elements disposed on the substrate is provided. The substrate comprises a polymer composition that comprises an electrically conductive filler distributed within a polymer matrix. The polymer matrix contains at least one thermoplastic high performance polymer having a deflection under load of about 40° C. or more as determined in accordance with ISO 75-2:2013 at a load of 1.8 MPa, and the polymer composition exhibits a dielectric constant of about 4 or more and a dissipation factor of about 0.3 or less, as determined at a frequency of 2 GHz.

A method for forming a metal film includes forming an oxide layer on a to-be-treated surface of a to-be-treated object by bringing the to-be-treated surface into contact with a reaction solution containing fluorine and an oxide precursor, removing fluorine in the oxide layer, supporting a catalyst on the oxide layer by bringing the oxide layer into contact with a catalyst solution, and depositing a metal film on the oxide layer by bringing the oxide layer into contact with an electroless plating liquid.

Method for forming a metal film includes forming an oxide layer on a to-be-treated surface of a to-be-treated object by bringing the to-be-treated surface into contact with a reaction solution containing fluorine and an oxide precursor, removing fluorine in the oxide layer, supporting a catalyst on the oxide layer by bringing the oxide layer into contact with a catalyst solution, and depositing a metal film on the oxide layer by bringing the oxide layer into contact with an electroless plating liquid.

A printed circuit board includes an insulating layer, a circuit pattern embedded in the insulating layer and including a first metal layer, a second metal layer and a third metal layer disposed between the first metal layer and the second metal layer, and a connection conductor disposed on one surface of the insulating layer and connected to the circuit pattern, wherein the first metal layer is exposed through the one surface of the insulating layer.

The present invention relates to printed circuit boards (PCBs), and more particularly, to methods of forming high aspect ratio through holes and high precision stub removal in a printed circuit board (PCB). The high precision stub removal processes may be utilized in removing long stubs and short stubs. In the methods, multiple holes of varying diameter and depth are drilled from an upper and/or lower surface of the printed circuit board utilizing drills of different diameters.

The present invention refers to a method of preparing a high density interconnect printed circuit board (HDI PCB) including microvias filled with copper comprising the steps of: a1) providing a multi-layer substrate comprising (i) a stack assembly of an electrically conductive interlayer embedded between two insulating layers, (ii) a cover layer, and (iii) a microvia extending from the peripheral surface and ending on the conductive interlayer; b1) depositing a conductive layer; or a2) providing a multi-layer substrate comprising (i) a stack assembly of an electrically conductive interlayer embedded between two insulating layers, (ii) a microvia extending from the peripheral surface and ending on the conductive interlayer; b2) depositing a conductive layer; and c) electrodepositing a copper filling in the microvia and a first copper layer on the conductive layer which form together a planar surface and the thickness of the first copper layer is from 0.1 to 3 μm.

The present invention refers to a method of preparing a high density interconnect printed circuit board (HDI PCB) or IC substrates including through-holes and/or grate structures filled with copper, which comprises the steps of: a) providing a multi-layer substrate; b) forming a non-copper conductive layer or a copper layer on the cover layer and on an inner surface of the through-hole, respectively on an inner surface of the grate structure; c) forming a patterned masking film; d) electrodepositing copper; e) removing the masking film; and f) electrodepositing a copper filling.

An insulation layer formation method comprises: a first step in which a surface treatment is applied to a base material to form thereon a high-resistance layer having high electric resistivity; a second step in which metal plating parts are formed on the base material that has undergone the first step in such a manner as to allow a high-resistance layer to be formed thereon; and a third process in which a high-resistance layer is formed on the base material that has undergone the second step.