Composite copper foil

Patent metadata

Field	Value
Publication number	US-2020332431-A1
Application number	US-201816762587-A
Country	US
Kind code	A1
Filing date	Nov 9, 2018
Priority date	Nov 10, 2017
Publication date	Oct 22, 2020
Grant date	—

Abstract

[Problem] An object is to provide novel composite copper foils. [Means to solve the problem] A composite copper foil comprises a copper foil and a layer of metal other than copper, the metal layer being formed on at least a part of a surface of the copper foil, wherein at least a part of the composite copper foil has protrusions on a surface thereof, and each protrusion has a height of 10 nm or more but 1000 nm or less in a cross-section of the composite copper foil.

First claim

1 . A composite copper foil comprising a copper foil and a layer of metal other than copper, the metal layer being formed on at least a part of a surface of the copper foil, wherein at least a part of the composite copper foil has protrusions on a surface thereof, and each protrusion has a height of 10 nm or more but 1000 nm or less in a cross-section of the composite copper foil.

2 . The composite copper foil according to claim 1 , wherein a percentage of Cu relative to the total weight of metal at a depth of 6 nm is 80% or less and a percentage of Cu relative to the total weight of metal at a depth with no oxygen is 90% or more.

3 . The composite copper foil according to claim 1 , wherein each protrusion has a height of 50 nm or more but 500 nm or less.

4 . The composite copper foil according to claim 1 , wherein a number of protrusions with a height of 50 nm or more is, on average, 15 or more and 100 or less per a 3.8-μm range of a cross-section of the composite copper foil.

5 . The composite copper foil according to claim 1 , wherein the height of each protrusion is measured as a distance between a midpoint of a line segment connecting the lowest points of depressions on both sides of a given protrusion and the highest point of the protrusion, in a scanning electron microscope image of a cross-section.

6 . The composite copper foil according to claim 1 , wherein the layer of metal is a uniform layer with no particles.

7 . The composite copper foil according to claim 1 , wherein a Cu/O ratio at a depth where the atomic percentage of Cu is 40% is 0.9 or more.

8 . The composite copper foil according to claim 1 , wherein the metal other than copper is at least one metal selected from the group consisting of Sn, Ag, Zn, Al, Ti, Bi, Cr, Fe, Co, Ni, Pd, Au, and Pt.

9 . A method of manufacturing a composite copper foil comprising:
a first step of oxidizing a surface of a copper foil; and a second step of plating the oxidized surface.

10 . The method according to claim 9 , wherein alkaline treatment is performed using an alkaline aqueous solution before the first step.

11 . The method according to claim 9 , wherein the oxidized surface of the copper foil is melted with a melting agent in the first step.

12 . The method according to claim 9 , wherein the plating in the second step is electroless plating using a catalyst.

13 . The method according to claim 9 , wherein the plating in the second step is electrolytic plating.

14 . The composite copper foil according to claim 2 , wherein each protrusion has a height of 50 nm or more but 500 nm or less.

15 . The composite copper foil according to claim 2 , wherein a number of protrusions with a height of 50 nm or more is, on average, 15 or more and 100 or less per a 3.8-μm range of a cross-section of the composite copper foil.

16 . The composite copper foil according to claim 2 , wherein the layer of metal is a uniform layer with no particles.

17 . The composite copper foil according to claim 4 , wherein the layer of metal is a uniform layer with no particles.

18 . The composite copper foil according to claim 2 , wherein a Cu/O ratio at a depth where the atomic percentage of Cu is 40% is 0.9 or more.

19 . The composite copper foil according to claim 4 , wherein a Cu/O ratio at a depth where the atomic percentage of Cu is 40% is 0.9 or more.

20 . The method according to claim 10 , wherein the plating in the second step is electrolytic plating.

Assignees

• Namics Corp

Inventors

• Sato Makiko
• Suzuki Osamu
• Obata Naoki
• Kokaji Yoshinobu

Classifications

• H05K2203/0793

  Aqueous alkaline solution, e.g. for cleaning or etching · CPC title

• H05K2201/0355

  Metal foils · CPC title

• H05K3/385

  by conversion of the surface of the metal, e.g. by oxidation, whether or not followed by reaction or removal of the converted layer · CPC title

• H05K3/384

  by plating · CPC title

• H05K1/09

  Use of materials for the {conductive, e.g. } metallic pattern · CPC title