Copper foil for printed circuit
A copper foil for printed circuits is prepared by forming a primary particle layer of copper on a surface of a copper foil, and then forming a secondary particle layer based on ternary alloy composed of copper, cobalt and nickel on the primary particle layer. The average particle size of the primary particle layer is 0.25 to 0.45 μm, and the average particle size of the secondary particles layer based on ternary alloy composed of copper, cobalt and nickel is 0.05 to 0.25 μm. Provided is a copper foil for printed circuits, in which powder fall from the copper foil can be reduced and the peeling strength and heat resistance can be improved by forming a primary particle layer of copper on a surface of a copper foil, and then forming a secondary particle layer based on copper-cobalt-nickel alloy plating on the primary particle layer.
1. A method for producing a copper foil for printed circuits comprising performing a first roughening treatment to form a roughening primary particle layer of copper on a surface of a copper foil, and then performing a second roughening treatment to deposit a roughening secondary particle layer based on ternary alloy composed of copper, cobalt and nickel on the roughening primary particle layer; wherein the surface is to be bonded to a resin base layer, the average particle size of the roughening primary particle layer is 0.25 to 0.45 μm, and the average particle size of the roughening secondary particle layer based on ternary alloy composed of copper, cobalt and nickel is 0.05 to 0.25 μm.
2. The method for producing a copper foil for printed circuits according to claim 1 , wherein the roughening primary particle layer and the roughening secondary particle layer are electroplated layers.
3. The method for producing a copper foil for printed circuits according to claim 2 , wherein the roughening secondary particle layer includes one or more dendritic particles grown on the roughening primary particle layer.
4. The method for producing a copper foil for printed circuits according to claim 3 , wherein a bonding strength of the roughening primary particle layer and the roughening secondary particle layer is 0.80 kg/cm or more.
5. The method for producing a copper foil for printed circuits according to claim 4 , wherein the bonding strength of the roughening primary particle layer and the roughening secondary particle layer is 0.90 kg/cm or more.
6. The method for producing a copper foil for printed circuits according to claim 5 , wherein a roughness, Rz, of a surface formed by the roughening primary particle layer and the roughening secondary particle layer is 1.5 μm or less.
7. The method for producing a copper foil for printed circuits according to claim 5 , wherein a roughness, Rz, of a surface formed by the roughening primary particle layer and the roughening secondary particle layer is 1.0 μm or less.
8. The method for producing a copper foil according to claim 1 , wherein the roughening secondary particle layer includes one or more dendritic particles grown on the roughening primary particle layer.
9. The method for producing a copper foil according to claim 1 , wherein a bonding strength of the roughening primary particle layer and the roughening secondary particle layer is 0.80 kg/cm or more.
10. The method for producing a copper foil according to claim 9 , wherein the bonding strength of the roughening primary particle layer and the roughening secondary particle layer is 0.90 kg/cm or more.
11. The method for producing a copper foil according to claim 1 , wherein a roughness, Rz, of a surface formed by the roughening primary particle layer and the roughening secondary particle layer is 1.5 μm or less.
12. The method for producing a copper foil according to claim 1 , wherein a roughness, Rz, of a surface formed by the roughening primary particle layer and the roughening secondary particle layer is 1.0 μm or less.
13. The method for producing a copper foil for printed circuits according to claim 1 , wherein the average particle size of the roughening primary particle layer is 0.35 to 0.45 μm.
14. The method for producing a copper foil for printed circuits according to claim 1 , wherein the average particle size of the roughening secondary particle layer is 0.15 to 0.25 μm.
15. The method for producing a copper foil for printed circuits according to claim 1 , wherein the method further comprises depositing a cobalt-nickel alloy plated layer as a heatproof layer on the roughening secondary particle layer.
16. The method for producing a copper foil for printed circuits according to claim 15 , wherein a total deposited amount of cobalt in the roughening secondary particle layer and the cobalt-nickel alloy plated layer is 300 to 4000 μg/dm 2 .
17. The method for producing a copper foil for printed circuits according to claim 15 , wherein a total deposited amount of cobalt in the roughening secondary particle layer and the cobalt-nickel alloy plated layer is 300 to 3500 μg/dm 2 .
18. The method for producing a copper foil for printed circuits according to claim 1 , wherein the method further comprises depositing a zinc-nickel alloy plated layer as a heatproof layer on the roughening secondary particle layer.
19. The method for producing a copper foil for printed circuits according to claim 18 , wherein a total deposited amount of cobalt in the roughening secondary particle layer is 300 to 4000 μg/dm 2 .
20. The method for producing a copper foil for printed circuits according to claim 18 , wherein a total deposited amount of nickel in the roughening secondary particle layer, and the zinc-nickel alloy plated layer does not exceed 1500 μg/dm 2 .
21. The method for producing a copper foil for printed circuits according to claim 18 , wherein a total deposited amount of cobalt in the roughening secondary particle layer is 300 to 3500 μg/dm 2 .
22. The method for producing a copper foil for printed circuits according to claim 18 , wherein a total deposited amount of nickel in the roughening secondary particle layer, and the zinc-nickel alloy plated layer does not exceed 1000 μg/dm 2 .
23. The method for producing a copper foil for printed circuits according to claim 1 , wherein the method further comprises depositing a cobalt-nickel alloy plated layer as a heatproof layer on the roughening secondary particle layer and a zinc-nickel alloy plated layer as a heatproof layer on the cobalt-nickel alloy plated layer.
24. The method for producing a copper foil for printed circuits according to claim 23 , wherein a total deposited amount of nickel in the roughening secondary particle layer, the cobalt-nickel alloy plated layer, and the zinc-nickel alloy plated layer does not exceed 1500 μg/dm 2 .
25. The method for producing a copper foil for printed circuits according to claim 23 , wherein a total deposited amount of nickel in the roughening secondary particle layer, the cobalt-nickel alloy plated layer, and the zinc-nickel alloy plated layer does not exceed 1000 μg/dm 2 .
26. The method for producing a copper foil for printed circuits according to claim 1 , wherein 10 to 30 mg/dm 2 of copper, 100 to 3000 μg/dm 2 of cobalt, and 50 to 500 μg/dm 2 of nickel are deposited during said second roughening treatment in the roughening secondary particle layer.