Abstract:
Disclosed herein is a printed circuit board, including: an insulating layer; a circuit layer formed on one surface of the insulating layer; and a via electrode penetrating through the insulating layer and being connected with the circuit layer, wherein the circuit layer is formed in a structure where different kinds of metal layers having different thermal conductivities are laminated.
Abstract:
A wiring board includes an electrode pad having a first surface and a second surface located on an opposite side from the first surface, a conductor pattern connected to the first surface of the electrode pad, and an insulator layer embedded with the electrode pad and the conductor pattern. The insulator layer covers an outer peripheral portion of the second surface of the electrode pad.
Abstract:
In one embodiment, a preliminary solder layer made of a Sn alloy is formed on a connecting pad of a wiring substrate. A solder bump made of a Sn alloy is formed on an electrode pad of a semiconductor chip. After contacting the preliminary solder layer and the solder bump, the preliminary solder layer and the solder bump are melted by heating to a temperature of their melting points or higher to form a solder connecting part made of a Sn alloy containing Ag and Cu. Only the preliminary solder layer of the preliminary solder layer and the solder bump is composed of a Sn alloy containing Ag.
Abstract:
A process for fabricating a circuit board is provided. In the process, first, a circuit substrate including an insulation layer and at least a pad contacting the insulation layer is provided. Next, a barrier material layer is formed on the circuit substrate. The barrier material layer completely covers the insulation layer and the pad. Then, at least one conductive bump is formed on the barrier material layer. The conductive bump is opposite to the pad, and the material of the barrier material layer is different from the material of the conductive bump. Next, a portion of the barrier material layer is removed by using the conductive bump as a mask, so as to expose the surface of the insulation layer and to form a barrier connected between the conductive bump and the pad.
Abstract:
A packaging substrate with conductive structure is provided, including a substrate body having at least one conductive pad on a surface thereof, a stress buffer metal layer disposed on the conductive pad, a solder resist layer disposed on the substrate body and having at least one opening therein for correspondingly exposing a portion of top surface of the stress buffer metal layer, a metal post disposed on a central portion of the surface of the stress buffer metal layer, and a solder bump covering the surfaces of the metal post. Therefore, a highly reliable conductive structure is provided, by using the stress buffer metal layer to release thermal stresses, and using the metal post and the solder bump to increase the height of the conductive structure.
Abstract:
A method of manufacturing a multilayer printed wiring board includes forming a first interlaminar resin insulating layer, a first conductor circuit on the first interlaminar resin insulating layer, a second interlaminar resin insulating layer, opening portions in the second interlaminar resin insulating layer to expose a face of the first conductor circuit, an electroless plating film on the second interlaminar resin insulating layer and the exposed face, and a plating resist on the electroless plating film. The method further includes substituting the electroless plating film with a thin film conductor layer, having a lower ion tendency than the electroless plating film, and a metal of the exposed face, forming an electroplating film including the metal on a portion of the electroless plating film and the thin film conductor layer, stripping the plating resist, and removing the electroless plating film exposed by the stripping.
Abstract:
A circuit board and a method for fabricating the same are disclosed. The circuit board includes: a carrier board having a circuit layer formed on at least one surface thereof; a first dielectric layer formed on the carrier board and having first openings for exposing a part of the circuit layer; conductive vias formed in the first openings; a second dielectric layer formed on the first dielectric layer and having second and third openings formed therein, wherein the second openings correspond to the first openings for exposing the conductive vias; and a multi-layered metal electroless plating circuit layer formed in the second and third openings for electrically connecting the circuit layer of the carrier board via the conductive vias, thereby allowing the multi-layered metal electroless plating circuit layer to be embedded into the first and second dielectric layers to enhance the bonding strength therebetween and increase the reliability of the circuit board and facilitate formation of fine circuits.
Abstract:
To produce a wiring substrate by employing a semi-additive method, the invention provides a production method of a wiring substrate, and a wiring substrate, that suppress the formation of undercut of an electrolytic copper plating layer during base etching and capable of ultra-fine wiring of a line/space size of 25/25 μm or below and further 10/10 μm or below. When producing a wiring substrate, the method of the invention includes the steps of applying electroless copper plating to a surface of a substrate made of a resin having an electric insulating property to form an electroless copper plating layer; applying a resist pattern exposing a portion for forming a wiring pattern on the surface of the electroless copper plating layer; plating metals different from copper or alloys containing at least one kind of the metals to the exposed portion to form an etching barrier plating layer; plating an etching barrier metal to form an etching barrier metal plating layer; applying electrolytic copper plating to the surface of the etching barrier metal plating layer to form wiring having a conductor layer including an electroless copper plating layer, the etching barrier metal plating layer and the electrolytic copper plating layer and the electrolytic copper plating layer; removing the resist pattern; and etching and removing the electroless copper plating layer exposed on the surface to form a wiring pattern.
Abstract:
Narrow conductors and narrow spaces therebetween, typically two or three mils wide, are fabricated on outer layers of a printed wiring board with built-up areas such as plated-through holes or conductors of widths greater than two or three mils. Gold is deposited over a copper clad substrate in a pattern defining the desired circuitry. Thereafter, solder is placed at the built-up areas and, using both the solder and the gold as resist or masks, the exposed copper is removed by etching. An organic resist material is used in lieu of solder when the built-up area comprises wide conductors or leads, e.g., power busses.