The present invention is directed to a method of preparing a substrate to improve the adherence of a metallic coating to the substrate and the product thereof. More particularly, a method of manufactiring a molded circuit board and unique circuit board produced thereby, is disclosed. A molding compound, such as an epoxy resin is blended with a plating additive, such as calcium carbonate that is relatively inert to the molding compound. The blended mix can then be molded into a desired shape which, for a printed circuit board, can be a relatively flat plate configuration with a recessed groove and hole formation pattern. The high relief areas of the circuit board can be masked with a protective material. The plating additive can then be chemically etched from the grooved recessed area and holes, for example, by a hydrochloric acid bath. Appropriate catalyst and accelerators can be applied to the recessed groove pattern before the protective mask material is removed. In one embodiment, an electroless plating nickel material can be deposited to permit it to penetrate the interstices or cavity pattern, left in the recessed groove and hole pattern by the etching of the plating additive. Copper can then be applied to the nickel pattern in the recessed grooves, for example, by dipping the substrate in an electroless plating copper solution. The substrate is heated to cure the epoxy resin for mechanically locking the metallic coating in the interstices, or cavities, left by the etching of the plating additive.
The present invention relates to methods and apparatus for plating a conductive material on a workpiece surface in a highly desirable manner. Using a workpiece-surface-influencing device, such as a mask or sweeper, that preferentially contacts the top surface of the workpiece, relative movement between the workpiece and the workpiece-surface-influencing device is established so that an additive in the electrolyte solution disposed on the workpiece and which is adsorbed onto the top surface is removed or otherwise its amount or concentration changed with respect to the additive on the cavity surface of the workpiece. Plating of the conductive material can place prior to, during and after usage of the workpiece-surface-influencing device, particularly after the workpiece surface influencing device no longer contacts any portion of the top surface of the workpiece, to achieve desirable semiconductor structures.
A method of making a printed circuit board includes providing a substrate coated with a conductive layer, developing a first photoresist layer on the conductive layer to define a first conductive pattern of the desired circuit configuration having a plurality of discontinuous segments, and a second conductive pattern interconnecting the discontinuous segments of the desired circuit configuration. A second layer of photoresist is positioned across the whole surface of the substrate except at least a selected portion of the first conductive pattern, and the substrate is electrically activated during a coating process for depositing conductive material on the selected portion of the first conductive pattern. The first conductive pattern is subsequently coated with photoresist, and the second conductive pattern, which is now exposed on the substrate, is subject to an etching process to effectively remove all of the second conductive pattern.
A compact and dense hybrid integrated circuit device which can be encapsulated by transfer molding can be manufactured by forming through holes in a ceramic or glass substrate, which through holes have a diameter of less than 0.2 mm, preferably less than 0.1 mm, a thin film circuit element being formed on one surface of the substrate, and a thin or thick film circuit element being formed on the other surface of the substrate. A fine through hole as mentioned above can be formed by laser drilling, etc., and plating.
Disclosed is a method of fabricating a novel printed circuit structure including a relatively small surface area of flexible material integral with a conventional glass epoxy carrier on which electrical contacts may be formed.
The insulating layer formation step of forming an insulating layer 24-1 on a base for resin application 20 by applying polymeric material, which has been diluted with a solvent, filled with inorganic filler to the base for resin application and by drying the base for resin application; the circuit formation portion forming step of creating a circuit formation portion and a via hole 25 in insulating layer 24-1 that has been formed in the above described insulating layer formation step by means of a laser treatment; and the circuit formation step of forming a circuit 23-1 by plating the circuit formation portion and via hole 25 that have been created in the above described circuit formation portion forming step are provided and the insulating layer formation step, the circuit formation portion forming step and the circuit formation step are repeated a plurality of times in this order and, thereby, a circuit formation part (multi-layered substrate) is manufactured. Accordingly, a multi-layered circuit, even of more than three layers, having an arbitrary circuit formation can easily be manufactured at a low cost.
