Method of manufacturing flexible film

Abstract

A method of manufacturing a flexible film is disclosed. The method includes (a) forming at least one hole on an insulating film, (b) after the step (a), forming a first metal layer on a first surface corresponding to an inner circumferential surface of the hole, and at least one of a second surface corresponding to an upper surface of the insulating film and a third surface corresponding to a lower surface of the insulating film, and (c) forming a second metal layer on the first metal layer. A thickness of the first metal layer is smaller than a thickness of the second metal layer.

1 . A method of manufacturing a flexible film comprising the step of:
 (a) forming at least one hole on an insulating film;   (b) after the step (a), forming a first metal layer on a first surface corresponding to an inner circumferential surface of the hole and at least one of a second surface corresponding to an upper surface of the insulating film and a third surface corresponding to a lower surface of the insulating film; and   (c) forming a second metal layer on the first metal layer,   wherein a thickness T 1  of the first metal layer is smaller than a thickness T 2  of the second metal layer.   
   
   
       2 . The method of  claim 1 , wherein the first metal layer is formed using an electroless plating method. 
   
   
       3 . The method of  claim 2 , wherein the first metal layer includes an upper layer formed of copper (Cu) and a lower layer formed of nickel (Ni). 
   
   
       4 . The method of  claim 1 , wherein the second metal layer is formed using an electrolytic plating method. 
   
   
       5 . The method of  claim 1 , wherein a diameter of the hole is approximately 30 μm to 1,000 μm. 
   
   
       6 . The method of  claim 1 , wherein the hole is formed using one of a chemical etching method, a drilling method, or a laser processing method. 
   
   
       7 . The method of  claim 1 , wherein the thickness T 1  of the first metal layer is approximately 0.02 μm to 0.2 μm. 
   
   
       8 . The method of  claim 1 , wherein the thickness T 2  of the second metal layer is approximately 2 μm to 50 μm. 
   
   
       9 . The method of  claim 1 , further comprising, before the step (b), performing a preprocessing on the insulating film 
   
   
       10 . The method of  claim 1 , wherein the first metal layer is formed of one selected from the group consisting of chromium (Cr), gold (Au), copper (Cu), and nickel (Ni). 
   
   
       11 . The method of  claim 1 , wherein the second metal layer is formed of gold (Au) or copper (Cu). 
   
   
       12 . The method of  claim 1 , wherein the insulating film is formed of one selected from the group consisting of polyester, polyimide, liquid crystal polymer, and fluorine resin. 
   
   
       13 . The method of  claim 1 , wherein the first surface makes an acute angle with the second surface. 
   
   
       14 . The method of  claim 1 , wherein the first surface makes a substantially right angle with the second surface. 
   
   
       15 . The method of  claim 1 , wherein the first surface makes an obtuse angle with the second surface. 
   
   
       16 . The method of  claim 1 , wherein a ratio of the thickness T 1  of the first metal layer to the thickness T 2  of the second metal layer is approximately 1:10 to 1:2,500. 
   
   
       17 . The method of  claim 1 , wherein a ratio of the thickness T 1  of the first metal layer to the thickness T 2  of the second metal layer is approximately 1:400 to 1:500. 
   
   
       18 . The method of  claim 1 , wherein a sum of the thickness T 1  of the first metal layer and the thickness T 2  of the second metal layer is substantially equal to or greater than 3/1,000 and less than ½ of a diameter of the hole. 
   
   
       19 . The method of  claim 1 , wherein a sum of the thickness T 1  of the first metal layer and the thickness T 2  of the second metal layer is approximately 1/100 to 1/10 of a diameter of the hole.