A process of fabricating an electromagnetic circuit includes providing a first sheet of dielectric material including a top surface having at least one conductive trace and depositing a solder bump on the at least one conductive trace. The process further includes applying a second sheet of dielectric material to the first sheet of dielectric material with bond film sandwiched in between, the second sheet of dielectric material having a through-hole providing access to the solder bump. The process further includes bonding the first and second dielectric materials to one another and removing bond film resin from the solder bump. The process further includes machining the solder bump by the drilling or milling process to achieve a desired amount of solder in the solder bump.

A wiring substrate includes a first insulating layer, a first conductor layer, a second insulating layer, a second conductor layer, a connection conductor penetrating through the second insulating layer and connecting the first and second conductor layers, and a coating film formed on a surface of the first conductor layer such that the coating film is adhering the first conductor layer and the second insulating layer. The first conductor layer includes a conductor pad and a wiring pattern such that the conductor pad is in contact with the connection conductor and the wiring pattern is covered by the coating film, the conductor pad of the first conductor layer has a surface facing the second insulating layer and having a first surface roughness higher than a surface roughness of a surface of the wiring pattern, and the coating film has opening such that the opening is exposing the conductor pad entirely.

A wiring substrate includes a first insulating layer, a first conductor layer, a second insulating layer, a second conductor layer, a connection conductor penetrating through the second insulating layer and connecting the first and second conductor layers, and a coating film formed on a surface of the first conductor layer such that the coating film is adhering the first conductor layer and the second insulating layer. The first conductor layer includes a conductor pad and a wiring pattern such that the conductor pad is in contact with the connection conductor and the wiring pattern is covered by the coating film, the conductor pad of the first conductor layer has a surface facing the second insulating layer and having a first surface roughness higher than a surface roughness of a surface of the wiring pattern, and the coating film has opening such that the opening is exposing the conductor pad entirely.

A method for manufacturing a multi-layer circuit board including an extreme fine via according to an embodiment of the disclosure may include: providing a board having one surface on at least a part of which an upper conductive layer is formed and the other surface on at least a part of which a lower conductive layer is formed; forming a lower metal layer on the other surface of the board; forming a first resist layer on the one surface of the board through a photolithography process, and forming a first opening on the first resist layer; forming a metal pillar by plating the first opening by using an electrolytic plating method; removing the first resist layer; forming an insulating layer on a location from which the first resist layer is removed; and evenly polishing the metal pillar and the insulating layer.

A method for manufacturing a multi-layer circuit board including an extreme fine via according to an embodiment of the disclosure may include: providing a board having one surface on at least a part of which an upper conductive layer is formed and the other surface on at least a part of which a lower conductive layer is formed; forming a lower metal layer on the other surface of the board; forming a first resist layer on the one surface of the board through a photolithography process, and forming a first opening on the first resist layer; forming a metal pillar by plating the first opening by using an electrolytic plating method; removing the first resist layer; forming an insulating layer on a location from which the first resist layer is removed; and evenly polishing the metal pillar and the insulating layer.

A method of producing a conductive path on a substrate including depositing on the substrate a layer of material having a thickness in the range of 0.1 to 5 microns, including metal particles having a diameter in the range of 10 to 100 nanometers, employing a patterning laser beam to selectably sinter regions of the layer of material, thereby causing the metal particles to together define a conductor at sintered regions and employing an ablating laser beam, below a threshold at which the sintered regions would be ablated, to ablate portions of the layer of material other than at the sintered regions.

A method of producing a conductive path on a substrate including depositing on the substrate a layer of material having a thickness in the range of 0.1 to 5 microns, including metal particles having a diameter in the range of 10 to 100 nanometers, employing a patterning laser beam to selectably sinter regions of the layer of material, thereby causing the metal particles to together define a conductor at sintered regions and employing an ablating laser beam, below a threshold at which the sintered regions would be ablated, to ablate portions of the layer of material other than at the sintered regions.

A printed circuit board according to one embodiment of the present invention comprises an insulation board and a plurality of metal electrodes disposed on the insulation board, wherein: the plurality of metal electrodes include a first electrode and a second electrode; the first electrode includes a first surface parallel to an upper surface of the insulation board, a second surface facing the first surface, a first side surface disposed between the first surface and the second surface, and a second side surface facing the first side surface; a part of the first side surface and a part of the second side surface protrude toward the outside of the first electrode in the direction parallel to the upper surface of the insulation board; the first side surface protrudes farther in an area adjacent to the first surface than in an area adjacent to the second surface; and the second side surface protrudes farther in the area adjacent to the second surface than in the area adjacent to the first surface.

A printed circuit board according to one embodiment of the present invention comprises an insulation board and a plurality of metal electrodes disposed on the insulation board, wherein: the plurality of metal electrodes include a first electrode and a second electrode; the first electrode includes a first surface parallel to an upper surface of the insulation board, a second surface facing the first surface, a first side surface disposed between the first surface and the second surface, and a second side surface facing the first side surface; a part of the first side surface and a part of the second side surface protrude toward the outside of the first electrode in the direction parallel to the upper surface of the insulation board; the first side surface protrudes farther in an area adjacent to the first surface than in an area adjacent to the second surface; and the second side surface protrudes farther in the area adjacent to the second surface than in the area adjacent to the first surface.

Disclosed herein are a solvent composition and methods of using the solvent composition. The solvent composition includes at least 80 wt. % of trans-1,2-dichloroetheylene (t-DCE), and 0.1 to 20 wt. % of at least one organic compound. The organic compound may be a hydrocarbon and/or an oxygenated solvent. The solvent composition may be used to clean a surface by contacting the surface with the composition to dissolve a contaminant on the surface. The composition may be used to remove a coating from a surface of a substrate by contacting the surface with the solvent composition to dissolve the coating and removing the composition containing the coating from the surface. The composition may also be used to deposit material on a substrate by dissolving the material in the solvent composition, applying the composition containing the material onto the substrate, and evaporating the composition from the substrate.