Abstract:
The present invention relates to a process for the manufacture of printed circuit boards. The method contemplates a novel processing sequence for this manufacturing process which method is particularly versatile in reducing the number of steps and variety of chemicals currently necessary to produce the circuit boards.
Abstract:
To provide a method of producing a multilayer printed wiring board that can be intended to have low-profile, light-weight and high-density wiring of a printed wiring board, and a multilayer printed wiring board produced by the method of producing a multilayer printed wiring board, the double-sided substrate is produced by the steps of forming an insulating resin layer on a metal foil; of forming a via hole in the insulating resin layer; of forming a first circuit pattern on the insulating resin layer and forming a conductive layer in the via hole, by plating; and of etching the metal foil to form it into a second circuit pattern. The produced double-sided substrate is used as a core substrate for producing multilayer printed wiring board by a laminate-en-bloc or a build-up method.
Abstract:
A method includes applying a first seed layer extending over a horizontal surface and via sidewalls of a dielectric material and exposed underlying contact metallization; removing at least some of the first seed layer from the contact metallization and the horizontal surface while leaving a sufficient amount of the first seed layer on the sidewalls as a catalyst for subsequent application of a third seed layer; sputtering a second seed layer over the contact metallization and the horizontal surface; using an electroless solution to react with the first seed layer and apply the third seed layer over the sidewalls; and electroplating an electroplated layer over the second and third seed layers.
Abstract:
As an electroless plating technique capable of surely promoting the plating reaction without Pd substitution reaction and fastening the plating deposition, there are proposed an electroless plating method of subjecting a primary plated film (or metal film) formed on a substrate to a secondary plating (or electroless plating), characterized in that the secondary plating is carried out after a surface potential of the primary plated film is adjusted so as to be more base than such a most base surface potential that a surface current density of the primary plated film is zero in an electroless plating solution for the secondary plating; and a pretreating solution for electroless plating comprising an alkali solution, reducing agent and completing agent; and an electroless plating bath suitable for use in this method.
Abstract:
A method includes applying a first seed layer extending over a horizontal surface and via sidewalls of a dielectric material and exposed underlying contact metallization; removing at least some of the first seed layer from the contact metallization and the horizontal surface while leaving a sufficient amount of the first seed layer on the sidewalls as a catalyst for subsequent application of a third seed layer; sputtering a second seed layer over the contact metallization and the horizontal surface; using an electroless solution to react with the first seed layer and apply the third seed layer over the sidewalls; and electroplating an electroplated layer over the second and third seed layers.
Abstract:
A method for interconnecting a multilayer metal network of an electronic circuit board is provided. In the method, the electronic circuit board is made up of a plurality of superimposed metal layers having an insulating layer disposed therebetween, wherein the material of the insulating layer is substantially inert to a catalytic activation bath and to chemical deposition of metal. A via hole is formed in the board having a first metal layer thereof as its bottom and traversing a second metal layer and using electroless deposition, metal is deposited in the via by growing the metal from the metal layers only.
Abstract:
A process for producing a printed wiring board characterized by forming a nickel layer by electroless plating and a copper layer formed thereon by electroless plating, or forming a copper undercoating layer before the nickel layer by electroless plating can produce printed circuit boards excellent in resistance to electrolytic corrosion and suitable for mounting parts in high density.
Abstract:
Both surfaces of a polyimide sheet are coated with a layer of electroless nickel or cobalt and can also be coated with a thin electroless copper layer on the Ni. or Co. This tenaciously bonded coating is subsequently treated in such a way so as to increase its permeability or porosity without substantially altering its resistive properties. The induced porosity allows water and other volatiles trapped in the dielectric polyimide sheet to be removed while the preserved electrical continuity of the metal layer is sufficient to support electrolytic copper plating which serves the dual purpose of providing a copper thickness useful for the subsequent production of electronic circuitry and preventing the readsorption of water into the dielectric core by permanently sealing or coating the porous metal layer.
Abstract:
A method for producing printed circuits. An epoxy resin reinforced with glass fiber is used as basis material, coated with copper, drilled and activated. In one embodiment, the circuit diagram is applied after covering the non-desired regions with a resistance, by screen or photo printing. A nickel, cobalt, or nickel-cobalt layer is deposited onto the circuit, the circuit is covered with a solder prevention lacquer, then the eyes and bore holes are covered with copper. Alternatively, after pre-treatment and activation, all areas except the soldering eyes and bore holes are covered with resist, a nickel, cobalt or nickel-cobalt layer is applied, the circuit diagram is printed using a resist, and the eyes and bore hole are treated as above.
Abstract:
Metal-clad laminates in which the metal coating of the laminate is only from about 1 micron to about 20 microns in thickness are prepared by depositing a copper coating on a substrate which has been treated with a release agent, treating the upper side of the metal layer to improve the adhesive properties of the metal, thereafter bonding the metal coating to a laminate and removing the substrate to thus prepare the desired metal-clad laminate.