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AssigneeMatsushita Electric Works, Ltd.
InventorsTakagi Masami, Nakayama Shunichi, Honda Kazuyoshi
Estimating the term…
A method of this invention for forming electrical wiring paths on an insulative substrate by means of an electroplating only at necessary portions on the insulative substrate comprises steps of forming on the insulative substrate a plated metal foundation layer which comprises an extremely thin conductive metal layer, closely fitting onto this extremely thin layer a first mask member from which the necessary portions for forming the electrical wiring paths are removed and having a surface to which no plating is applicable, forming a first plated layer of such metal as copper on the extremely thin conductive metal layer over the first mask member, closely fitting onto the first plated layer a second mask member from which some but not all portion of the electrical wiring paths of the first mask member are removed, forming a second plated layer of a second metal on the second mask member, and removing the first and second mask members and thus exposed portions of the extremely thin conductive metal layer, whereby the electrical wiring paths can be formed of a first metal only at the necessary portions on the insulative substrate, so that the amount to be used of such conductive first metal as copper can be reduced and it can be made possible to have a different second metal selectively plated on some but not all of such electrical wiring paths so as to improve environmental durability, to have the same first and second metal plated so as to improve the environmental durability, and to have the same first and second metal plated so as to increase the thickness of such electrical wiring paths and thereby increase the current flowing capacity.
A method of forming electrically conductive paths on an insulative substrate comprising the steps of
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
Reinforcing of the conductive pattern: characterised by selective plating, e.g. for finish plating of pads
In which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern: by semi-additive…
Electrical arrangements not otherwise provided for: high current adaptations, e.g. printed high current conductors or using auxiliary non-printed…
High current adaptations, e.g. printed high current conductors or using auxiliary non-printed means; Fine and coarse circuit patterns on one…:…
Term ended 24 Jan 2001 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
This invention relates to methods of forming electrically conductive wiring paths on insulative substrates and, more particularly, to a method of forming the electrical wiring paths on the insulative substrate by means of an electroplating for interconnecting electronic circuit components disposed on a single substrate.
As a general one of conventional methods of the kind referred to, there has been known a method of forming the electrical wiring paths by performing, for example, an etching, leaving necessary portions of a copper foil surface of a copperclad laminate in which a copper foil is adhered over the entire surface of one or both sides. According to this method, however, there has been a problem that the same is uneconomical and wasting of resources since portions other than the electrical wiring paths of the copper foil are removed by a chemical liquid of ferric chloride or the like.
As a solution to this problem, it is sufficient to have a conductive metal material adhered only to those portions on the insulative substrate where the electrical wiring paths are to be formed, and many methods for this purpose have been suggested. In these methods, the portions on the insulative substrate other than the electrical-wiring-path forming portions are masked so that only the necessary portions will have the conductive metal material adhered thereto and, for this masking, it has been practiced to paint or print a masking material onto the insulative substrate or to adhere such a soft packing material as silicone rubber.
FIG. 1 is a vertically sectioned view of the insulative substrate 1 of the present invention on which the extremely thin conductive metal layer 2 is formed,
FIG. 2 is a perspective view of the mask member in FIG. 1,
FIG. 3 is a sectioned view showing another embodiment of the mask member of the present invention,
In accordance with the present invention, the foregoing objects are achieved in such that a mask member is closely fitted onto an insulative substrate on which an extremely thin conductive metal layer is formed, a metal plating is then applied thereon, the mask member is removed, thereafter portions of the metal layer on which the metal plating is not applied are removed, a second mask is further closely fitted onto the cut metal layer if required, and the metal plating is further performed.
An example is as follows:
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