Printed circuits

Claim 2

A print transfer article for use in making an electrically conductive circuit article and suitable for transferring a metal circuit to a dielectric solid support surface which comprises (a) a solid release surface: (b) a layer, in the form of at least an electric circuit element, deposited on the release surface containing a thermosetting resin composition which includes (i) a thermosetting resin and (ii) electrically conductive metal particles, wherein the amount of metal particles in the resin composition is from about 54 to about 87 percent of the volume fraction based on the volume of the dried layer; and optionally, (c) a layer of a reactive adhesive provided over the thermosetting resin composition.

Claim 3

The article of claim 1 wherein the amount of metal particles in the resin composition is from about 68 to about 87 percent of the volume fraction based on the volume of the dried layer.

Claim 4

A printing ink comprising in admixture (i) a thermosetting resin in an amount of about 13 to about 32 percent volume fraction and (ii) an amount of electrically conductive metal particles from about 68 to about 87 percent volume fraction of the dried ink, said ink being suitable for printing and on compacting and curing forming an electric circuit element satisfying the Soldering Standard Test.

Claim 5

A printing ink comprising in admixture (i) a thermosetting resin in an amount of about 13 to about 32 percent volume fraction and (ii) an amount of electrically conductive metal particles from about 68 to about 87 percent volume fraction of the dried ink, said ink being suitable for printing and on compacting and curing forming an electric circuit element satisfying the Soldering Standard Test.

Claim 6

4 . The process of forming a printed circuit article which comprises: (1) providing a release surface; (2) applying an ink comprising a thermosetting resin composition containing a desired amount of the electrically conductive metal particles to the release surface as a film (viz. pathway) in the configuration of at least an electric circuit element; (3) providing a dielectric surface; (4) providing a reactive adhesive interface capable of inter-acting with the thermosetting resin composition of (2) above and the dielectric surface; (5) bringing together the release surface and the dielectric surface so that the film of electrical circuit element is facing the dielectric surface and is separated therefrom by the adhesive interface; (6) applying sufficient heat and pressure to form a composite structure whereby the thermosetting resin is cured and the adhesive is inter-acted whereby the electrical circuit is transferred from the release surface to become effectively bonded to the dielectric surface and providing an electrical circuit having a good platability by electroless plating technique.

Claim 7

4 . The process of forming a printed circuit article which comprises: (1) providing a release surface; (2) applying an ink comprising a thermosetting resin composition containing a desired amount of the electrically conductive metal particles to the release surface as a film (viz. pathway) in the configuration of at least an electric circuit element; (3) providing a dielectric surface; (4) providing a reactive adhesive interface capable of inter-acting with the thermosetting resin composition of (2) above and the dielectric surface; (5) bringing together the release surface and the dielectric surface so that the film of electrical circuit element is facing the dielectric surface and is separated therefrom by the adhesive interface; (6) applying sufficient heat and pressure to form a composite structure whereby the thermosetting resin is cured and the adhesive is inter-acted whereby the electrical circuit is transferred from the release surface to become effectively bonded to the dielectric surface and providing an electrical circuit having a good platability by electroless plating technique.

Claim 8

5 . The process of claim 4 wherein the release surface is removed from the composite structure and said resin and adhesive are fully cured in step 6.

Claim 9

6 . The process of claim 4 wherein the volume fraction of metal particles is from about 68 to 87 percent and the volume fraction of thermosetting resin is from about 13 to 32 percent.

Claim 10

7 . A printed circuit article comprising: (a) a solid dielectric support surface having a surface; and (b) a first layer or pathway on said surface and comprising a thermoset resin and electrically conductive metal particles, in the configuration of at least an electric circuit element, said metal particles being present in an amount of from about 68 to about 87 percent by weight of the volume fraction based on the weight of the layer, said electric circuit element having good plateability by electroless plating techniques.

Claim 11

7 . A printed circuit article comprising: (a) a solid dielectric support surface having a surface; and (b) a first layer or pathway on said surface and comprising a thermoset resin and electrically conductive metal particles, in the configuration of at least an electric circuit element, said metal particles being present in an amount of from about 68 to about 87 percent by weight of the volume fraction based on the weight of the layer, said electric circuit element having good plateability by electroless plating techniques.

Claim 12

A printed circuit article in accordance with claim 7 wherein said article satisfies the Soldering Standard Test.

Claim 13

9 . A printed circuit article in accordance with claim 8 wherein said article satisfies the Platability Standard Test.

Claim 14

A printed circuit article in accordance with claim 7 wherein said first layer has a portion lying substantially'in a first plane and a portion at an angle thereto extending over a portion of said support surface which is non-planar.

Claim 15

A print transfer composition comprising a solid release surface having coated thereon a pathway in the configuration of an electric circuit or a precursor to or an element of an electric circuit formed from a thermosetting resin composition comprising electrically conductive metal particles to satisfy the Soldering Standard Test when transferred and to provide at least an electric circuit or element of an electric circuit having a surface resistivity of below 0.1 ohm per square.

Claim 16

A print transfer composition comprising a solid release surface having coated thereon a pathway in the configuration of an electric circuit or a precursor to or an element of an electric circuit formed from a thermosetting resin composition comprising electrically conductive metal particles to satisfy the Soldering Standard Test when transferred and to provide at least an electric circuit or element of an electric circuit having a surface resistivity of below 0.1 ohm per square.

Claim 17

A print transfer composition as defined in claim 11 wherein the thermosetting resin has advanced by some degree of crosslinking.

Claim 18

A print transfer composition as defined in claim 11 wherein the thermosetting resin is essentially tack free.

Claim 19

An electrical system comprising: (1) a dielectric substrate: (2) electrically conductive pathways comprising 93 to 98% metal particles by weight of the pathway and a cured plastic: (3) an adhesive holding said pathway to said substrate, said pathways being able to withstand 260°C for 20 seconds without appreciably changing their shape.

Claim 20

An electrical system comprising: (1) a dielectric substrate: (2) electrically conductive pathways comprising 93 to 98% metal particles by weight of the pathway and a cured plastic: (3) an adhesive holding said pathway to said substrate, said pathways being able to withstand 260°C for 20 seconds without appreciably changing their shape.

Claim 21

15 . A low temperature method of forming a circuit pattern on a plastic substrate which comprises the steps of: a) applying a slurry, comprising a vaporizable solvent, powdered metal and a small quantity of thermosetting binder in the shape of the circuit pattern desired to a removable layer; b) vaporizing the solvent; c) covering the powdered metal and binder with an adhesive layer to hold the powdered metal and carrier in place on the removable layer; d) laminating the plastic substrate with pressure and heat to cause compacting of said powder and bonding of said compacted powder to said substrate by said adhesive layer, said heat being insufficient to destroy said adhesive, substrate and removable layer; and e) separating the removable layer.

Claim 22

15 . A low temperature method of forming a circuit pattern on a plastic substrate which comprises the steps of: a) applying a slurry, comprising a vaporizable solvent, powdered metal and a small quantity of thermosetting binder in the shape of the circuit pattern desired to a removable layer; b) vaporizing the solvent; c) covering the powdered metal and binder with an adhesive layer to hold the powdered metal and carrier in place on the removable layer; d) laminating the plastic substrate with pressure and heat to cause compacting of said powder and bonding of said compacted powder to said substrate by said adhesive layer, said heat being insufficient to destroy said adhesive, substrate and removable layer; and e) separating the removable layer.

Claim 23

A circuit transfer system comprising a separatable layer, said layer having a circuit pattern of metal powder substantially free from organic material on a surface thereof and an adhesive overlying said circuit pattern and at least a portion of the layer.

Claim 24

A circuit transfer system comprising a separatable layer, said layer having a circuit pattern of metal powder substantially free from organic material on a surface thereof and an adhesive overlying said circuit pattern and at least a portion of the layer.

Claim 25

An electrical system comprising a dielectric substrate and a compacted electrically conductive pathway comprising 90 to 98 per cent metal particulate by weight of the pathway and which contains by weight 15 to 50 per cent of noble metal in the pathway with the remainder non-noble metal and/or inert particles and an organic binder, the thickness of the compacted pathway varying not more than + 5 microns and having a conductivity below 0.1 ohms/sq.

Claim 26

An electrical system comprising a dielectric substrate and a compacted electrically conductive pathway comprising 90 to 98 per cent metal particulate by weight of the pathway and which contains by weight 15 to 50 per cent of noble metal in the pathway with the remainder non-noble metal and/or inert particles and an organic binder, the thickness of the compacted pathway varying not more than + 5 microns and having a conductivity below 0.1 ohms/sq.

Claim 29

19· The method of producing electrically conductive pathways on a dielectric substrate comprising compacting and heating a curable resin containing a noble metal, tin and nickel particulate to cure the same and compact the same to reduce the height thereof on the substrate by at least about 25 per cent from its initial height.

Claim 30

19· The method of producing electrically conductive pathways on a dielectric substrate comprising compacting and heating a curable resin containing a noble metal, tin and nickel particulate to cure the same and compact the same to reduce the height thereof on the substrate by at least about 25 per cent from its initial height.

Claim 31

20 . A printed circuit board comprising an insulating support surface carrying a conductive circuit pattern having an inner surface and outer surface with said circuit pattern inner surface adhered to said support surface by an organic adhesive layer, said organic adhesive layer being a thermosetting organic adhesive, said conductive circuit pattern having an organic thermosetting binder in an amount of about 32 to about 13% by volume of said pattern, said adhesive and binder being stable at temperatures of up to at least 260°C for times of at least 20 seconds, said pattern further comprised of conductive metal particles in an amount of from about 68 to about 87% by volume, said conductive circuit pattern having a gradient of binder extending from surface to surface with more binder at said inner surface, said circuit pattern having a surface resistivity of between 0.1 to 0.01 ohm/sq., said circuit pattern being, a) capable of being electrolessly plated with nickel without surface activation, b) repeatedly resolderable at a temperature of 260°C for 20 seconds, c) having a high bond strength, and d) being plattable and wettable with solder.

Claim 32

20 . A printed circuit board comprising an insulating support surface carrying a conductive circuit pattern having an inner surface and outer surface with said circuit pattern inner surface adhered to said support surface by an organic adhesive layer, said organic adhesive layer being a thermosetting organic adhesive, said conductive circuit pattern having an organic thermosetting binder in an amount of about 32 to about 13% by volume of said pattern, said adhesive and binder being stable at temperatures of up to at least 260°C for times of at least 20 seconds, said pattern further comprised of conductive metal particles in an amount of from about 68 to about 87% by volume, said conductive circuit pattern having a gradient of binder extending from surface to surface with more binder at said inner surface, said circuit pattern having a surface resistivity of between 0.1 to 0.01 ohm/sq., said circuit pattern being, a) capable of being electrolessly plated with nickel without surface activation, b) repeatedly resolderable at a temperature of 260°C for 20 seconds, c) having a high bond strength, and d) being plattable and wettable with solder.