Nano-twinned copper foil, electronic element and methods for manufacturing the same

Abstract

A nano-twinned copper foil is provided, which comprises: plural twinned grains, wherein at least part of the plural twinned grains are formed by stacking plural nano-twins along a [111] crystal axis. The nano-twinned copper foil has a first surface and a second surface opposite to the first surface, and 80% or more of areas of the first surface and the second surface respectively exposes (111) planes of the nano-twins. In addition, the present invention further provides a method for manufacturing the aforesaid nano-twinned copper foil, an electronic element comprising the same, and a method for manufacturing the electronic element.

1 . A nano-twinned copper foil, comprising:
 plural twinned grains, wherein at least part of the plural twinned grains are formed by stacking plural nano-twins along a [111] crystal axis;   wherein the nano-twinned copper foil has a first surface and a second surface opposite to the first surface, and 80% or more of areas of the first surface and the second surface respectively exposes (111) planes of the nano-twins.   
     
     
         2 . The nano-twinned copper foil of  claim 1 , wherein more than 80% of the volume of the nano-twinned copper foil comprises the plural nano-twins. 
     
     
         3 . The nano-twinned copper foil of  claim 2 , wherein the at least part of the plural twinned grains are columnar twinned grains. 
     
     
         4 . The nano-twinned copper foil of  claim 2 , wherein diameters of the plural twinned grains respectively range from 0.1 μm to 50 μm. 
     
     
         5 . The nano-twinned copper foil of  claim 2 , wherein thicknesses of the plural twinned grains respectively range from 0.1 μm to 500 μm. 
     
     
         6 . The nano-twinned copper foil of  claim 2 , wherein the at least part of the plural twinned grains are connected to each other. 
     
     
         7 . The nano-twinned copper foil of  claim 1 , wherein an angle included between a stacking direction of the plural nano-twins and a thickness direction of the nano-twinned copper foil ranges from 0 degree to 20 degrees. 
     
     
         8 . The nano-twinned copper foil of  claim 1 , wherein a thickness of nano-twinned copper foil ranges from 10 μm to 500 μm. 
     
     
         9 . The nano-twinned copper foil of  claim 1 , wherein roughnesses of the first surface and the second surface are respectively less than or equal to 20 nm. 
     
     
         10 . A method for preparing a nano-twinned copper foil, comprising the following steps:
 providing an electroplating device, comprising an anode, a cathode, a plating solution and a power supply, wherein the power supply is connected to the cathode and the anode respectively, and the cathode and the anode are immersed in the plating solution;   performing an electroplating process by using the power supply to grow a nano-twinned copper layer on the cathode; and   removing the cathode and polishing a surface of the nano-twinned copper layer to obtain the nano-twinned copper foil of  claim 1 , wherein the surface of the nano-twinned copper foil is in contact with the cathode before removing the cathode.   
     
     
         11 . The method of  claim 10 , wherein the cathode comprises:
 a substrate; and   a titanium-tungsten bonding layer disposed on the substrate, wherein the nano-twinned copper layer is formed on the titanium-tungsten bonding layer.   
     
     
         12 . The method of  claim 10 , wherein the titanium-tungsten bonding layer comprises a titanium-tungsten alloy represented by the following formula (I):
   Ti x W 100-x    (I)
   wherein, x ranges from 5 to 20.   
     
     
         13 . The method of  claim 10 , wherein a thickness of the titanium-tungsten bonding layer ranges from 100 nm to 200 nm. 
     
     
         14 . The method of  claim 10 , wherein the substrate is a silicon substrate. 
     
     
         15 . The method of  claim 10 , further comprising a step: polishing another surface of the nano-twinned copper layer away from the cathode before removing the cathode. 
     
     
         16 . An electronic component, comprising:
 a first substrate;   a second substrate; and   a bonding unit disposed between the first substrate and the second substrate, wherein the bonding unit is the nano-twinned copper foil of  claim 1 .   
     
     
         17 . The electronic component of  claim 16 , wherein the first substrate and the second substrate are respectively a metal substrate or a substrate on which a metal layer is formed, wherein a material of the metal substrate or the metal layer comprises at least one selected from the group consisting of copper, silver, gold, palladium, nickel and platinum. 
     
     
         18 . A method for preparing an electronic component, comprising the following steps:
 providing a first substrate and a second substrate;   disposing a bonding unit between the first substrate and the second substrate, and bonding the first substrate and the second substrate by using the bonding unit to form an electronic component, wherein the bonding unit is the nano-twinned copper foil of  claim 1 .   
     
     
         19 . The method of  claim 18 , wherein the first substrate and the second substrate are respectively a metal substrate or a substrate on which a metal layer is formed, wherein a material of the metal substrate or the metal layer comprises at least one selected from the group consisting of copper, silver, gold, palladium, nickel and platinum.