Carrier-attached ultra-thin copper foil and method for producing the same

Abstract

A carrier-attached ultra-thin copper foil and a method for producing the same are provided. The carrier-attached ultra-thin copper foil includes a copper foil carrier, a release layer, and an ultra-thin copper foil layer. The release layer is formed on a side surface of the copper foil carrier. The release layer contains a copper-containing organic compound, and a chemical structure of the copper-containing organic compound has at least a copper-nitrogen bond (Cu—N bond). The ultra-thin copper foil layer is formed on a side surface of the release layer away from the copper foil carrier. The copper foil carrier is capable of being separated from the ultra-thin copper foil layer through the release layer.

What is claimed is: 
     
         1 . A method for producing a carrier-attached ultra-thin copper foil, comprising:
 providing a copper foil carrier;   forming a release layer on a side surface of the copper foil carrier; wherein the release layer contains a copper-containing organic compound, and a chemical structure of the copper-containing organic compound has at least a copper-nitrogen bond (Cu—N bond); and   forming an ultra-thin copper foil layer on a side surface of the release layer away from the copper foil carrier;   wherein the copper foil carrier is capable of being separated from the ultra-thin copper foil layer through the release layer.   
     
     
         2 . The method according to  claim 1 , wherein the release layer has at least two infrared absorption peaks respectively at a first position between 1020 cm −1  and 1025 cm −1  and a second position between 1098 cm −1  and 1103 cm −1  as analyzed by Fourier transform infrared spectroscopy (FTIR). 
     
     
         3 . The method according to  claim 1 , wherein the copper-containing organic compound in the release layer is an organic copper complex. 
     
     
         4 . The method according to  claim 1 , wherein the release layer is formed on the side surface of the copper foil carrier by immersing the copper foil carrier in an electroplating solution and performing an electroplating process on the copper foil carrier; wherein the electroplating solution contains: a nitrogen-containing heterocyclic compound, a copper-containing metal salt, and a buffering agent; wherein, in the electroplating solution, a concentration of the nitrogen-containing heterocyclic compound is between 0.05 g/L and 40 g/L, a concentration of the copper-containing metal salt is between 5 g/L and 100 g/L, and a concentration of the buffering agent is between 10 g/L and 600 g/L. 
     
     
         5 . The method according to  claim 1 , wherein, in the electroplating solution, a weight ratio among the nitrogen-containing heterocyclic compound, the copper-containing metal salt, and the buffering agent is 1:5 to 40:100 to 600. 
     
     
         6 . The method according to  claim 4 , wherein the nitrogen-containing heterocyclic compound is a bicyclic nitrogen-containing heterocyclic compound; wherein the copper-containing metal salt is selected from the group consisting of copper pyrophosphate, copper sulfate, copper carbonate, copper acetate, copper nitrate, copper oxide, cuprous cyanide, sodium copper cyanide, and potassium copper cyanide; wherein the buffering agent is selected from the group consisting of potassium pyrophosphate, boric acid, sulfuric acid, ammonium sulfate, citric acid, ammonium citrate, sodium citrate, sodium acetate, sodium carbonate, potassium tartrate, and sodium gluconate. 
     
     
         7 . The method according to  claim 4 , wherein the copper foil carrier is electroplated in the electroplating solution for a predetermined time ranging from 1 to 20 seconds; wherein an electric current density of the electroplating process ranges from 0.1 ASD to 5 ASD, and a temperature of the electroplating solution ranges from 30° C. to 60° C. 
     
     
         8 . The method according to  claim 1 , wherein the chemical structure of the copper-containing organic compound further has a carbon-hydrogen bond (C—H bond), a carbon-nitrogen bond (C—N bond), and a nitrogen-hydrogen bond (N—H bond). 
     
     
         9 . The method according to  claim 1 , wherein a nitrogen content of the release layer analyzed by X-ray photoelectron spectroscopy (XPS) ranges from 0.1 wt % to 25 wt %. 
     
     
         10 . The method according to  claim 9 , wherein elemental ratios of the release layer analyzed by X-ray photoelectron spectroscopy (XPS) are that: an N1s peak area to a total peak area is 15 to 25 atomic %, an O1s peak area to the total peak area is 25 to 35 atomic %, a C1s peak area to the total peak area is 30 to 40 atomic %, and a Cu2p peak area to the total peak area is 5 to 18 atomic %; wherein a ratio of the Cu2p peak area relative to the Nis peak area ranges from 0.3 to 0.9. 
     
     
         11 . A carrier-attached ultra-thin copper foil, comprising:
 a copper foil carrier;   a release layer formed on a side surface of the copper foil carrier; wherein the release layer contains a copper-containing organic compound, and a chemical structure of the copper-containing organic compound has at least a copper-nitrogen bond (Cu—N bond); and   an ultra-thin copper foil layer formed on a side surface of the release layer away from the copper foil carrier;   wherein the copper foil carrier is capable of being separated from the ultra-thin copper foil layer through the release layer.   
     
     
         12 . The carrier-attached ultra-thin copper foil according to  claim 10 , wherein the release layer has at least two infrared absorption peaks respectively at a first position of between 1020 cm −1  and 1025 cm −1  and a second position of between 1098 cm −1  and 1103 cm −1  as analyzed by Fourier transform infrared spectroscopy (FTIR); wherein the copper-containing organic compound in the release layer is an organic copper complex. 
     
     
         13 . The carrier-attached ultra-thin copper foil according to  claim 11 , wherein a thickness of the copper foil carrier is between 10 micrometers and 50 micrometers, a thickness of the release layer is between 20 nanometers and 300 nanometers, and a thickness of the ultra-thin copper foil layer is between 1 micrometer and 5 micrometers. 
     
     
         14 . The carrier-attached ultra-thin copper foil according to  claim 11 , wherein the release layer is formed on the side surface of the copper foil carrier by immersing the copper foil carrier in an electroplating solution and performing an electroplating process on the copper foil carrier; wherein the electroplating solution contains: a nitrogen-containing heterocyclic compound, a copper-containing metal salt, and a buffering agent. 
     
     
         15 . The carrier-attached ultra-thin copper foil according to  claim 11 , wherein a surface roughness of a side surface of the ultra-thin copper foil layer away from the release layer is greater than a surface roughness of another side surface of the ultra-thin copper foil layer that is in contact with the release layer. 
     
     
         16 . The carrier-attached ultra-thin copper foil according to  claim 11 , wherein a peeling strength of the copper foil carrier peeled from the ultra-thin copper foil layer through the release layer is between 1 gf/cm and 20 gf/cm according to JIS Z 0237-2009. 
     
     
         17 . The carrier-attached ultra-thin copper foil according to  claim 11 , wherein the release layer further has absorption peaks including a carbon-hydrogen bond (C—H bond), a carbon-nitrogen bond (C—N bond), and a nitrogen-hydrogen bond (N—H bond) as analyzed by Fourier transform infrared spectroscopy (FTIR). 
     
     
         18 . The carrier-attached ultra-thin copper foil according to  claim 11 , wherein a nitrogen content of the release layer analyzed by X-ray photoelectron spectroscopy (XPS) ranges from 0.1 wt % to 25 wt %; wherein elemental ratios of the release layer analyzed by X-ray photoelectron spectroscopy (XPS) are that: an N1s peak area to a total peak area is 15 to 25 atomic %, an O1s peak area to the total peak area is 25 to 35 atomic %, a C1s peak area to the total peak area is 30 to 40 atomic %, and a Cu2p peak area to the total peak area is 5 to 18 atomic %; wherein a ratio of the Cu2p peak area relative to the N1s peak area ranges from 0.3 to 0.9. 
     
     
         19 . The carrier-attached ultra-thin copper foil according to  claim 18 , wherein the N1s peak area is 20.63 atomic %, the O1s peak area is 29.78 atomic %, the C1s peak area is 36.77 atomic %, and the Cu2p peak area is 12.82 atomic %; wherein the ratio of the Cu2p peak area relative to the N1s peak area is 0.6214. 
     
     
         20 . The carrier-attached ultra-thin copper foil according to  claim 17 , wherein the release layer exhibits a curve chart of Cu2p peak analyzed by X-ray photoelectron spectroscopy (XPS) and focused ion beam (FIB).