Electrodeposited copper foil with low repulsive force

Patent metadata

Field	Value
Publication number	US-2018298508-A1
Application number	US-201715490608-A
Country	US
Kind code	A1
Filing date	Apr 18, 2017
Priority date	Apr 18, 2017
Publication date	Oct 18, 2018
Grant date	—

Abstract

The present disclosure relates to a copper foil that exhibits surprising low repulsive force characteristics; and to methods for manufacturing such copper foils. Typically, the copper foil has (a) a lightness L* value of the nodule untreated side, based on the L*a*b color system, in the range of 75 to 90 and (b) a normal tensile strength in the range of 40 kgf/mm 2 to 55 kgf/mm 2 . The disclosure further relates to flexible printed circuit boards and electronic devices using the above-mentioned copper foils for forming conductive lines therein.

First claim

1 .- 10 . (canceled)

11 . A method for manufacturing electrodeposited copper foil comprising:
(a) preparing a copper sulfate electrolyte solution with a chlorine ion concentration of 20 ppm or less; (b) performing an electrochemical reaction on the copper sulfate electrolyte solution using a current density of about 80 A/dm 2 or less to yield a bare copper foil; and (c) processing the bare copper foil to yield the electrodeposited copper foil, so that the electrodeposited copper foil has:
(i) a lightness L* value of a nodule untreated side, based on the L*a*b color system, in the range of 75 to 90; and
(j) a normal tensile strength in the range of 40 kgf/mm 2 to 55 kgf/mm 2 .
wherein the processing comprises a surface treatment process.

12 . The process of claim 11 , wherein the chlorine ion concentration is about 20 ppm, and wherein the normal tensile strength is in the range of 40 kgf/mm 2 to 45 kgf/mm 2 and the degree of curl, as measured by the lamination curl test, is in the range of 0.45 mm to 1.5 mm.

13 . The process of claim 11 , wherein the chlorine ion concentration is about 15 ppm, and wherein the normal tensile strength is in the range of 45 kgf/mm 2 to 50 kgf/mm 2 and the degree of curl, as measured by the lamination curl test, is in the range of 1.5 mm to 2.5 mm.

14 . The process of claim 11 , wherein the chlorine ion concentration is about 10 ppm, and wherein the normal tensile strength is in the range of 50 kgf/mm 2 to 55 kgf/mm 2 and the degree of curl, as measured by the lamination curl test, is in the range of 2.5 mm to 3.0 mm.

15 . The process of claim 11 , wherein the current density is about 60 A/dm 2 , and the electrodeposited copper foil further comprising a low angle grain boundary (LAGB) value measured after annealing is in the range of 3.5% to 3.8% and the lightness L* value of the nodule untreated side is in the range of 75 to 80.

16 . The process of claim 11 , wherein the current density is about 70 A/dm 2 , and the electrodeposited copper foil further comprising the LAGB value measured after annealing is in the range of 5.8% to 6.0% and the lightness L* value of the nodule untreated side is in the range of 83 to 87.

17 . The process of claim 11 , wherein the current density is about 80 A/dm 2 , and the electrodeposited copper foil further comprising the LAGB value measured after annealing is in the range of 6.4% to 7.0% and the lightness L* value of the nodule untreated side is in the range of 87 to 90.

18 .- 20 . (canceled)

21 . The process of claim 11 , wherein the surface treatment process comprises subjecting the copper foil to an acid washing.

22 . The process of claim 21 , further comprising the step of washing the copper foil with water after the acid washing.

23 . The process of claim 11 , wherein the surface treatment step comprises a surface roughening of the copper foil.

24 . The process of claim 23 , wherein the surface roughening comprises the step of forming nodules on one of the deposit side or drum side of the electrodeposited copper foil.

25 . The process of claim 24 , further comprising the step of cover plating the nodules.

26 . The process of claim 25 , further comprising the step of alloying a metal layer onto the cover plating.

27 . The process of claim 24 , further comprising the step of passivating each of the deposit side and drum side of the copper foil.

28 . The process of claim 26 , wherein the step of passivating comprises applying a passivating agent comprising zinc.

29 . The process of claim 27 , further comprising the step of forming an anti-tarnish layer by applying a chromic acid solution to the zinc passivated copper foil.

30 . The process of claim 29 , further comprising applying an organic anti-tarnish solution over the chromic treated zinc passivated copper foil.

31 . The process of claim 30 , wherein the organic anti-tarnish solution comprises at least one member selected from the group consisting of triazoles, thiazoles, imidazoles and their derivatives.

32 . The process of claim 30 , further comprising treating only the Zn/Cr passivated nodule layer with a silane coupling agent.

33 . The process of claim 32 , wherein the Zn/Cr passivated nodule layer is washed with water upon completion of the anti-tarnish layer and the silane coupling agent is applied without drying the water washed Zn/Cr passivated nodule layer.

Assignees

• Chang Chun Petrochemical Co Ltd

Inventors

• Lai Yao-Sheng
• Cheng Kuei-Seng
• Huang Jian-Ming

Classifications

• C25D1/20

  Separation of the formed objects from the electrodes {with no destruction of said electrodes} · CPC title

• C25D5/48

  After-treatment of electroplated surfaces · CPC title

• H01M4/045

  Electrochemical coating; Electrochemical impregnation · CPC title

• C25D1/04 Primary

  Wires; Strips; Foils · CPC title

• C25D7/0614

  Strips or foils · CPC title