Method for electroplating a plastic substrate

Abstract

A method for electroplating a plastic substrate includes the following steps, a plastic substrate is firstly provided. The plastic substrate is then pretreated to form a noble metal coating. The noble metal coating is coated with a copper coating. A first chrome coating is electroplated onto the copper coating using a first electrolyte including a chromic component. A second chrome coating is electroplated onto the first chrome coating using a second electrolyte including a chromyl component.

1 . A method for electroplating a plastic substrate, comprising the steps of:
 providing a plastic substrate;   metalizing the plastic substrate;   forming a copper coating onto the noble metal coating;   electroplating a first chrome coating onto the copper coating using a first electrolyte including a chromic component; and   electroplating a second chrome coating onto the first chrome coating using a second electrolyte including a chromyl component.   
   
   
       2 . The method as claimed in  claim 1 , wherein the plastic substrate is made from one of acrylonitrile butadiene styrene, poly methyl methacrylate, and polycarbonate. 
   
   
       3 . The method as claimed in  claim 1 , wherein the noble metal coating is made of palladium. 
   
   
       4 . The method as claimed in  claim 1 , wherein the copper coating is formed by electroplating. 
   
   
       5 . The method as claimed in  claim 1 , wherein the copper coating is formed by physical vapor deposition. 
   
   
       6 . The method as claimed in  claim 1 , wherein the first electrolyte includes boric acid. 
   
   
       7 . The method as claimed in  claim 1 , wherein the chromic component is one of chrome sulfate and chrome chloride. 
   
   
       8 . The method as claimed in  claim 1 , wherein the electroplating for forming the first chrome coating is carried out in the first electrolyte at a temperature from about 28° C. to about 52° C. and a current density from about 3 to about 20 ampere per square decimeter. 
   
   
       9 . The method as claimed in  claim 1 , wherein the second electrolyte includes sulfate acid, the electroplating for forming the first chrome coating being curried out in the second electrolyte at a temperature from about 30° C. to about 60° C. and a current density from about 5 to about 40 ampere per square decimeter. 
   
   
       10 . A method for electroplating a plastic substrate, comprising the steps of:
 providing a plastic substrate;   forming a noble metal coating on the plastic substrate;   forming a copper coating onto the noble metal coating;   electroplating a first chrome coating onto the copper coating using a chromic electrolyte; and   electroplating a second chrome coating onto the first chrome coating using a chromyl electrolyte including a chromyl component.   
   
   
       11 . The method as claimed in  claim 10 , wherein the plastic substrate is made from one of acrylonitrile butadiene styrene, poly methyl methacrylate, and polycarbonate. 
   
   
       12 . The method as claimed in  claim 10 , wherein the noble metal coating is made of palladium. 
   
   
       13 . The method as claimed in  claim 10 , wherein the copper coating is formed by electroplating. 
   
   
       14 . The method as claimed in  claim 10 , wherein the copper coating is formed by physical vapor deposition. 
   
   
       15 . The method as claimed in  claim 10 , wherein the chromic electrolyte includes boric acid and a chromic salt. 
   
   
       16 . The method as claimed in  claim 15 , wherein the chromic salt is one of chrome sulfate and chrome chloride. 
   
   
       17 . The method as claimed in  claim 10 , wherein the electroplating for forming the first chrome coating is curried out in the chromic electrolyte at a temperature from about 28° C. to about 52° C. and a current density from about 3 to about 20 ampere per square decimeter. 
   
   
       18 . The method as claimed in  claim 10 , wherein the chromyl electrolyte includes a chromyl component and sulfate acid, the electroplating for forming the first chrome coating being curried out in the chromyl electrolyte at a temperature from about 30° C. to about 60° C. and a current density from about 5 to about 40 ampere per square decimeter.