Porous nickel thin film and manufacturing method thereof

Abstract

Provided is a porous nickel thin film having a flexibility value of no more than 15.0 N/mm.

1 . A porous nickel thin film having a flexibility value of 15.0 N/mm or less, the flexibility value being a value measured by a method comprising the steps of:
 supporting an entire periphery of the nickel thin film with a subject supporting jig so as to form an unsupported region with a closed shape in the nickel thin film;   measuring a relationship between a force applied to a pushing jig and a displacement amount of the pushing jig by pushing one end of the pushing jig against the unsupported region perpendicularly to the nickel thin film; and   obtaining a value (N/mm) by dividing the force (N) applied to the pushing jig by the displacement amount (mm) of the pushing jig, as the flexibility value.   
     
     
         2 . The porous nickel thin film according to  claim 1 , having a thickness of 0.1 to 100 μm. 
     
     
         3 . A method for manufacturing a porous nickel thin film, comprising the steps of:
 forming a nickel plated film on a conductive substrate by use of a nickel electroplating bath containing a nickel salt and a surfactant; and   heat-treating the nickel plated film so as to burn and remove the surfactant taken in the nickel plated film.   
     
     
         4 . The method according to  claim 3 , wherein
 the porous nickel thin film has a flexibility value of 15.0 N/mm or less, and the flexibility value is a value measured by a method comprising the steps of:   supporting an entire periphery of the nickel thin film with a subject supporting jig so as to form an unsupported region with a closed shape in the nickel thin film;   measuring a relationship between a force applied to a pushing jig and a displacement amount of the pushing jig by pushing one end of the pushing jig against the unsupported region perpendicularly to the nickel thin film; and   obtaining a value (N/mm) by dividing the force (N) applied to the pushing jig by the displacement amount (mm) of the pushing jig, as the flexibility value.   
     
     
         5 . The method according to  claim 3 , wherein
 the surfactant contains an anionic surfactant.   
     
     
         6 . The method according to  claim 5 , wherein
 the anionic surfactant contains a compound selected from the group consisting of a polyoxyalkylene alkyl ether sulfate, a polyoxyalkylene alkyl ether carboxylate, and an alkylbenzene sulfonate.   
     
     
         7 . The method according to  claim 3 , wherein
 the step of forming a nickel plated film includes a step of carrying out pulse electroplating.   
     
     
         8 . The method according to  claim 3 , wherein
 the conductive substrate is a Ti substrate, a Cu substrate, an SUS substrate, a glass given electrical conductivity, or a resin given electrical conductivity.   
     
     
         9 . The method according to  claim 3 , further comprising a step of peeling the porous nickel thin film off the conductive substrate. 
     
     
         10 . The method according to  claim 3 , wherein
 a concentration of the nickel salt in the nickel electroplating bath is 100 g/L to 800 g/L.   
     
     
         11 . The method according to  claim 3 , wherein
 the nickel salt is at least one compound selected from a group consisting of nickel sulfamate, nickel chloride, nickel sulfate, and nickel citrate.   
     
     
         12 . The method according to  claim 3 , wherein
 a concentration of the surfactant in the nickel electroplating bath is 0.1 mL/L to 100 mL/L.   
     
     
         13 . The method according to  claim 3 , wherein
 a pH of the nickel electroplating bath is 2.0 to 4.5.   
     
     
         14 . The method according to  claim 3 , wherein
 the step of heat-treating comprises a step of carrying out a heat treatment with a temperature of 350° C. to 900° C.   
     
     
         15 . The method according to  claim 3 , wherein
 the step of heat-treating comprises a step of carrying out a heat treatment for a period of 10 minutes to 120 minutes.   
     
     
         16 . The method according to  claim 7 , wherein
 the step of carrying out pulse electroplating comprises a step of carrying out pulse electroplating with an average current density of 1 A/dm 2  to 20 A/dm 2 .   
     
     
         17 . The method according to  claim 7 , wherein
 the step of carrying out pulse electroplating comprises a step of carrying out pulse electroplating with a ton/toff of 0.1 to 10, the ton/toff being a ratio of pulse applying time “ton” to pulse pause time “toff.”   
     
     
         18 . The method according to  claim 7 , wherein
 the step of carrying out pulse electroplating comprises a step of carrying out pulse electroplating with a pulse frequency of 0.1 to 1000 (Hz).