Abstract:
An opening is made in a resin (20) with a laser to form a viahole. A copper foil (22) etched into a thin film (3 νm) to lower the heat conductivity is used as a conformal mask, thereby making an opening (20a) in the resin (20) by fewer times of irradiation with a pulse laser beam. This prevents formation of any undercut in the resin (20) on which an interlayer resin-insulating layer is to be formed, enabling improvement in the connection reliability of the viahole.
Abstract:
A multilayer printed wiring board (11) is formed with a plurality of conductor layers laminated as a whole with insulating layers interposed, a non-penetrating via hole (3) provided in the insulating layer (2) as bottomed by the conductor layer (1a) exposed, a plated layer (4) provided inside the via hole (3) for electric connection between the conductor layers (1a,1b), the via hole (3) being formed to be of a concave curved surface of a radius in a range of 20 to 100 µm in axially sectioned view at continuing zone of inner periphery to bottom surface of the via hole (3), whereby the equipotential surfaces occurring upon plating the plated layer (4) are curved along the continuing zone to unify the density of current for rendering the plated layer (4) uniform in the thickness without being thinned at the continuing zone.
Abstract:
A multilayered wiring board using conductive pillars for the interconnection of wiring layers. Since through holes are bored in the via lands of the wiring layers of the multilayered wiring board, the stress applied between the conductive pillars and wiring layers can be released at the time of connecting the conductive pillars to the via lands. Since the external side face of each conductive pillar smoothly continues to the surface of the via land at the contact section between the conductive pillar and the via land, the notch effect is relieved. Therefore, the reliability of the interconnection is secured even when a stress is applied to the connections during the manufacturing of the multilayered wiring board, and the mounting of electronic parts, etc.
Abstract:
An opening is made in a resin (20) with a laser to form a viahole. A copper foil (22) etched into a thin film (3 νm) to lower the heat conductivity is used as a conformal mask, thereby making an opening (20a) in the resin (20) by fewer times of irradiation with a pulse laser beam. This prevents formation of any undercut in the resin (20) on which an interlayer resin-insulating layer is to be formed, enabling improvement in the connection reliability of the viahole.
Abstract:
A method of manufacturing a multi layered printed circuit board incorporating a substrate (230) on which a lower conductive circuit (234) is formed, an insulating resin layer (250) and an upper conductive circuit (258) formed on the lower conductive circuit (234) and having a structure that the lower conductive circuit (234) and the upper conductive circuit (258) are connected to each other through a via hole (260), the method of manufacturing a multilayered printed circuit board comprising the steps of: forming the lower conductive circuit (234) on the substrate (230); forming the insulating resin layer (250) on the lower conductive circuit; previously forming a coarsened surface (250a) on the surface of the insulating resin layer (250); forming, on the coarsened surface (250a), a metal layer (251) having an opening (251a) through which a portion of the coarsened surface (250a) is exposed; irradiating the coarsened surface (250a) exposed through the opening (251a) with a laser beam to remove the insulating resin layer to form an opening (248) for the via hole; and forming the upper conductive circuit (258) and the via hole (260).
Abstract:
A method of manufacturing a multi layered printed circuit board incorporating a substrate (230) on which a lower conductive circuit (234) is formed, an insulating resin layer (250) and an upper conductive circuit (258) formed on the lower conductive circuit (234) and having a structure that the lower conductive circuit (234) and the upper conductive circuit (258) are connected to each other through a via hole (260), the method of manufacturing a multilayered printed circuit board comprising the steps of: forming the lower conductive circuit (234) on the substrate (230); forming the insulating resin layer (250) on the lower conductive circuit; previously forming a coarsened surface (250a) on the surface of the insulating resin layer (250); forming, on the coarsened surface (250a), a metal layer (251) having an opening (251a) through which a portion of the coarsened surface (250a) is exposed; irradiating the coarsened surface (250a) exposed through the opening (251a) with a laser beam to remove the insulating resin layer to form an opening (248) for the via hole; and forming the upper conductive circuit (258) and the via hole (260).
Abstract:
A method of manufacturing a printed wiring board (210) comprising at least two insulating layers (211,212,213) made of a synthetic resin, an innerlayer conductor circuit (221-225) arranged between the insulating layers, and a plurality of blind via- holes (3A-3E) formed from an outermost surface toward the innerlayer conductor circuit (221-225) and having different depths by successively irradiating a laser beam every a portion forming the blind via-hole (3A-3E), characterized in that a shallowest blind via-hole (3A-3E) is formed as a standard hole by using a standard laser beam (242) having an energy strength required for the formation of the standard hole, and the standard laser beam (242) is irradiated plural times in the formation of the blind via-holes having deeper depths (3B,3D,3E).
Abstract:
A printed wiring board (501) comprising two or more insulating layers (516,518) on an innerlayer conductor circuit (562), a via-hole (502) extending from an outermost surface of the insulating layer (516) through the two or more insulating layers (516,518) to the innerlayer conductor circuit (562) and an inner metal plated film (521) formed in the via-hole (502) so as to electrically connect to the innerlayer conductor circuit (562) to an outer conductor circuit (561) arranged on the outermost surface, characterized in that an annular dummy land (504) for reinforcement having an opening hole (540) around the via-hole (502) is arranged in a boundary portion (517) facing the two or more insulating layers (516,518) to each other and is joined to the inner metal plated film (521).