Plural copper-layer treatment of copper foil and article made thereby

Claim 2

A process for improving the bond strength of copper foil through the electrochemical treatment of a surface thereof comprising said surface to a two-step electrochemical pretreatment prior to the application of said electrochemical treatment, the first step of said pretreatment comprising subjecting said surface to an arsenic and copper-containing electrolyte under conditions such as to electrolytically deposit thereon a first copper layer which increases the bond strength of the raw foil; the second step of said pretreatment comprising subjecting said surface to a copper-containing electrolyte under conditions such as to electrolytically deposit thereon a second copper layer which substantially conforms to the configuration of the first layer and reduces the powder transfer characteristics of said first layer; and then giving said pretreated foil an electrochemical treatment in which said surface is subjeced to a copper-containing electrolyte under conditions such as to electrolytically deposit thereon a third, copper-containing, microcrystalline layer which further increases the bond strength of said foil.

Claim 3

A process as defined in claim 1 wherein said electrochemical treatment involves the use of an arsenic and copper-containing electrolyte.

Claim 4

A process as defined in claim 2 wherein the copper and arsenic content in the electrolyte in said first step and in said electrochemical treatment are approximately as follows: ______________________________________ Electrochemical 1st Step Treatment ______________________________________ Cu (g/l) 10-40 4-10 As (g/l) .03-5 0-.5. ______________________________________

Claim 5

A process as defined in claim 2 wherein the copper and arsenic content in the electrolyte in said first step and in said electrochemical treatment are approximately as follows: ______________________________________ Electrochemical 1st Step Treatment ______________________________________ Cu (g/l) 10-40 4-10 As (g/l) .3-1.5 0-.5. ______________________________________

Claim 6

A process as defined in claim 2 wherein a sufficient amount of arsenic is present in the electrolyte in said first step of said pretreatment to increase the bond strength resulting from said electrochemical treatment over what it would have been had said electrochemical treatment been applied to foil which had not been pretreated.

Claim 7

A process as defined in claim 1 wherein approximately 1-4 grams of electrodeposit per square meter of foil surface is deposited during said electrochemical treatment.

Claim 8

A process for improving the bond strength of copper foil comprising subjecting a surface of said foil to three electrochemical treatments such as to electrode-posit thereon three copper layers, said three treatments being carried out approximately under the following conditions: ______________________________________ Treatment Treatment Treatment No. 1 No. 2 No. 3 ______________________________________ Cu (g/l) 10-40 40-120 4-10 H.sub.2 SO.sub.4 (g/l) 30-100 30-100 30-100 As (g/l) .03-5 -- 0-.5 Electrolyte Temp- 60-120 90-160 70-100 erature (°F.) Deposition time (sec.) 5-30 5-30 5-30 Cathode current 100-300 100-300 50-200 density (ASF). ______________________________________

Claim 9

A process for improving the bond strength of copper foil comprising subjecting a surface of said foil to three electrochemical treatments such as to electrode-posit thereon three copper layers, said three treatments being carried out approximately under the following conditions: ______________________________________ Treatment Treatment Treatment No. 1 No. 2 No. 3 ______________________________________ Cu (g/l) 10-40 40-120 4-10 H.sub.2 SO.sub.4 (g/l) 30-100 30-100 30-100 As (g/l) .03-5 -- 0-.5 Electrolyte Temp- 60-120 90-160 70-100 erature (°F.) Deposition time (sec.) 5-30 5-30 5-30 Cathode current 100-300 100-300 50-200 density (ASF). ______________________________________

Claim 10

A process as defined in claim 7 wherein the conditions for said three treatments are approximately as follows: ______________________________________ Treatment Treatment Treatment No. 1 No. 2 No. 3 ______________________________________ Cu (g/l) 20-30 60-80 4.5-5.5 H.sub.2 SO.sub.4 (g/l) 50-100 50-100 50-65 As (g/l) .3-1.5 -- .15-.3 Electrolyte Temp- 70-100 100-140 75-85 erature (°F.) Deposition Time 10-14 8-12 8-12 (secs.) Cathode current 150-300 150-250 50-150 Density (ASF). ______________________________________

Claim 11

A process as defined in claim 7 wherein the conditions for said three treatments are approximately as follows: ______________________________________ Treatment Treatment Treatment No. 1 No. 2 No. 3 ______________________________________ Cu (g/l) 30 70 5 H.sub.2 SO.sub.4 (g/l) 60 60 60 As (g/l) 1.25 -- .25 Electrolyte Temp- 75° 120 80 erature (°F.) Deposition Time 12 12 12 (secs.) Cathode Current 160 200 60 Density (ASF). ______________________________________

Claim 12

A process for improving the bond strength of copper foil through the electrochemical treatment of a surface thereof comprising subjecting said surface to a two-step electrochemical treatment, the first step of said treatment comprising subjecting said surface to an arsenic and copper-containing electrolyte under conditions such as to electrolytically deposit thereon a first copper layer which increases the bond strength of the raw foil; the second step of said treatment comprising subjecting said surface to a copper-containing electrolyte under conditions such as to electrolytically deposit thereon a second copper layer which substantially conforms to the configuration of the first layer and reduces the powder transfer characteristics of said first layer.

Claim 13

A process for improving the bond strength of copper foil through the electrochemical treatment of a surface thereof comprising subjecting said surface to a two-step electrochemical treatment, the first step of said treatment comprising subjecting said surface to an arsenic and copper-containing electrolyte under conditions such as to electrolytically deposit thereon a first copper layer which increases the bond strength of the raw foil; the second step of said treatment comprising subjecting said surface to a copper-containing electrolyte under conditions such as to electrolytically deposit thereon a second copper layer which substantially conforms to the configuration of the first layer and reduces the powder transfer characteristics of said first layer.

Claim 14

The product of the process of claim 1.

Claim 15

The product of the process of claim 6.

Claim 16

The product of the process of claim 2.

Claim 17

The product of the process of claim 3.

Claim 18

The product of the process of claim 4.

Claim 19

The product of the process of claim 5.

Claim 20

The product of the process of claim 7.

Claim 21

The product of the process of claim 8.

Claim 22

The product of the process of claim 9.

Claim 23

The product of the process of claim 10.

Claim 24

Copper foil having on a face thereof three electrodeposited superposed layers, the layer closest to said face containing arsenic and copper, the intermediate layer being a copper electrodeposit which substantially conforms to the configuration of said closest layer and serves to reduce the powder transfer characteristics of said closest layer; the third outermost layer being copper-containing and microcrystalline, said third layer increasing the bond strength of said foil over and above the bond strength provided by said closest and intermediate layers.

Claim 25

Copper foil having on a face thereof three electrodeposited superposed layers, the layer closest to said face containing arsenic and copper, the intermediate layer being a copper electrodeposit which substantially conforms to the configuration of said closest layer and serves to reduce the powder transfer characteristics of said closest layer; the third outermost layer being copper-containing and microcrystalline, said third layer increasing the bond strength of said foil over and above the bond strength provided by said closest and intermediate layers.

Claim 26

Copper foil as defined in claim 21 wherein said third outermost layer is copper-arsenic.

Claim 27

A printed circuit board comprised of a dielectric substrate bonded to which is the copper foil of claim 21, the portion of said foil being closest to said substrate being said third layer.

Claim 28

A printed circuit board comprised of a dielectric substrate bonded to which is the copper foil of claim 22, the portion of said foil being closest to said substrate being said third layer. .Iadd. 25. A process for improving the bond strength of copper foil through the electrochemical treatment of a surface thereof comprising subjecting said surface to a two-step electrochemical pretreatment prior to the application of said electrochemical treatment, the first step of said pretreatment comprising subjecting said surface to an electrolyte containing (1) copper and (2) arsenic, antimony, bismuth, selenium or tellurium under conditions such as to electrolytically deposit thereon a first copper layer which increases the bond strength of the raw foil; the second step of said pretreatment comprising subjecting said surface to a copper-containing electrolyte under conditions such as to electrolytically deposit thereon a second copper layer which substantially conforms to the configuration of the first layer and reduces the powder transfer characteristics of said first layer; and then giving said pretreated foil an electrochemical treatment in which said surface is subjected to a copper-containing electrolyte under conditions such as to electrolytically deposit thereon a third, copper-containing microcrystalline layer which further increases the bond strength of said foil. .Iaddend..Iadd. 26. A process as defined in claim 25 wherein approximately 1-4 grams of electrodeposit per square meter of foil surface is deposited during said electrochemical treatment. .Iaddend..Iadd. 27. A process as defined in claim 25 wherein said electrochemical treatment involves the use of an electrolyte containing (1) copper and (2) arsenic, antimony, bismuth, selenium or tellurium. .Iaddend..Iadd. 28. A process as defined in claim 27 wherein a sufficient amount of arsenic, antimony, bismuth, selenium or tellurium is present in the electrolyte in said first step of said pretreatment to increase the bond strength resulting from said electrochemical treatment over what it would have been had said electrochemical treatment been applied to foil which had not been pretreated. .Iaddend..Iadd. 29. A process for improving the bond strength of copper foil through the electrochemical treatment of a surface thereof comprising subjecting said surface to a two-step electrochemical treatment, the first step of said treatment comprising subjecting said surface to an electrolyte containing (1) copper and (2) arsenic, antimony, bismuth, selenium or tellurium under conditions such as to electrolytically deposit thereon a first copper layer which increases the bond strength of the raw foil; the second step of said treatment comprising subjecting said surface to a copper-containing electrolyte under conditions such as to electrolytically deposit thereon a second copper layer which substantially conforms to the configuration of the first layer and reduces the powder transfer characteristics of said first layer. .Iaddend..Iadd. 30. The product of the process of claim 25. .Iaddend..Iadd. 31. The product of the process of claim 26. .Iaddend..Iadd. 32. The product of the process of claim 27. .Iaddend..Iadd. 33. The product of the process of claim 28. .Iaddend..Iadd. 34. The product of the process of claim 29. .Iaddend..Iadd. 35. Copper foil having on a face thereof three electrodeposited superposed layers, the layer closest to said face containing (1) copper and (2) arsenic, antimony, bismuth, selenium or tellurium, the intermediate layer being a copper electrodeposit which substantially conforms to the configuration of said closest layer and serves to reduce the powder transfer characteristics of said closest layer; the third outermost layer being copper-containing and microcrystalline, said third layer increasing the bond strength of said foil over and above the bond strength provided by said closest and intermediate layers. .Iaddend..Iadd. 36. Copper foil as defined in claim 35 wherein said third outermost layer also contains arsenic, antimony, bismuth, selenium or tellurium. .Iaddend..Iadd. 37. A printed circuit board comprised of a dielectric substrate bonded to which is the copper foil of claim 35, the portion of said foil being closest to said substrate being said third layer. .Iaddend..Iadd. 38. A printed circuit board comprised of a dielectric substrate bonded to which is the copper foil of claim 36, the portion of said foil being closest to said substrate being said third layer. .Iaddend..Iadd. 39. Copper foil having on a face thereof two electrodeposited superposed layers, the layer closest to said face containing (1) copper and (2) arsenic, antimony, bismuth, selenium or tellurium, the second layer being a copper electrodeposit which substantially conforms to the configuration of said closest layer and serves to reduce the powder transfer characteristics of said closest layer. .Iaddend..Iadd. 40. Copper foil as defined in claim 39 wherein said second layer contains copper and arsenic. .Iaddend..Iadd. 41. A printed circuit board comprised of a dielectric substrate bonded to which is the copper foil of claim 39, the portion of said foil being closest to said substrate being said second layer. .Iaddend. .Iadd. 42. A printed circuit board comprised of a dielectric substrate bonded to which is the copper foil of claim 40, the portion of said foil being closest to said substrate being said second layer. .Iaddend. .Iadd. 43. A process as defined in claim 25 wherein in said first step of said pretreatment the surface is subjected to an electrolyte containing (1) copper and (2) arsenic, antimony or bismuth. .Iaddend..Iadd. 44. A process as defined in claim 27 wherein said electrochemical treatment involves the use of an electrolyte containing (1) copper and (2) arsenic, antimony or bismuth. .Iaddend.