Fabrication of a printed circuit board with metal-filled channels
OwnerVito D. Elardeinventor
Life of this patent
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Abstract
A plastic substrate is injection molded to provide a pattern of channels in at least one of its sides to define a predetermined set of conductive paths. Both the surfaces of the channels and the non-channel surfaces therebetween are metalling through one or more steps of flame spraying, a combination of electroless plating and electroplating, gas plating or vacuum deposition. In one form of the invention the metallization over the non-channel surfaces is removed by abrading. In another form of the invention the initial metallization over the non-channel surfaces is coated with a resist prior to the deposition of another metal layer. The metal covering the channels is subsequently removed by stripping the resist and etching away the initial metallization.
Claims15
A process of fabricating a circuit board comprising the steps of:
- injection molding a plastic substrate having a pattern of channels in at least one of its sides defining channel surfaces and non-channel surfaces, the pattern of channels representing a predetermined set of conductive paths extending along the one side of the substrate;
- depositing at least one layer of metal onto the one side of the substrate over the channel surfaces and the non-channel surfaces thereof, the depositing being performed according to a method selected from the group consisting of flame spraying, a combination of electroless plating and electroplating, gas plating and vacuum deposition;
- and
- removing the metal above the non-channel surfaces of the one side of the substrate to delineate a conductive pattern of metal-filled channels.
A process of fabricating a circuit board comprising the steps of:
- injection molding a substantially planar substrate of a material selected from the group consisting of polyimides, modified polyimides, polyether sulfone, polyphenylene sulfide resins, PET type polyester, polyetherimide, modified polysulfone and Nylon;
- applying a layer of a resist to define a reverse image of a conductive pattern;
- flame spraying a bond enhancing metal layer onto the substrate, the first metal selected from the group consisting of copper, brass alloy, aluminum, zinc and silver solder braze alloy;
- depositing a second metal layer onto the bond enhancing metal layer;
- and
- etching away portions of the metal layers above the resist to delineate the conductive pattern.
A process of fabricating a circuit board comprising the steps of:
- injection molding a substrate having a pattern of channels in at least one of its sides defining channel surfaces and non-channel surfaces, the pattern of channels representing a predetermined set of conductive paths extending along the one side of the substrate, the substrate being molded of a material selected from the group consisting of polyimide, modified polyimide, polyetherimide, polyether sulfone, polyphenylene sulfide resin, PET type polyester, modified polysulfone and Nylon;
- electroless plating a layer of a first metal onto the channel surfaces and non-channel surfaces of the substrate;
- applying a layer of resist over the portions of the layer of the first metal which overlie the non-channel surfaces of the substrate;
- electroplating a layer of a second metal over the portions of the layer of the first metal which overlie the channel portions of the substrate;
- and
- chemically removing the resist and the portions of the layer of the first metal which overlie the non-channel surfaces of the substrate.
Dependencies are inferred from the claim text.