Device for the metallisation of printed forms which are equipped with electrically conductive tracks and associated metallisation method

Abstract

The invention relates to a printed circuit which is equipped with electrically conductive tracks and which can be obtained by means of gravure printing. Gravure printing can be used to obtain conductive tracks of a very small thickness, such that said tracks have a high electrical resistance. In order to reduce the electrical resistance of the tracks ( 30 ) thus obtained, the invention consists in connecting at least two first electrodes ( 9, 8 ) to opposite portions ( 17, 18 ) of the same track while the middle ( 19 ) of said track is immersed in an electrolytic bath ( 7 ). Moreover, the bath is connected to a second electrode ( 26 ) which is in turn connected to a second potential ( 15 ) having an opposite polarity to that of a first potential ( 14 ) connecting the first electrodes.

1 . A metallization device for a dielectric support coated with patterns of electrically conductive tracks, and comprising 
 an electrolytic station,    this electrolytic station comprises an electrolytic bath, first electrodes connected to a source of a first electrical potential, with a polarity opposite to that of a second electrical potential, the bath being subjected to the second electrical potential by one or more second electrodes of the electrolytic station, characterized in that    the dielectric support is immersed in the electrolytic bath so that the tracks of the same pattern are connected in short-circuit to the first potential and to the second potential, and    at least two first electrodes are connected to opposite pattern sections of the same pattern while the middle section of this same pattern is immersed in the bath.    
   
   
       2 . The device according to  claim 1 , further characterized in that 
 two first electrodes are separated from one another by a distance less than a length of a pattern measured along the support relative to the direction of movement of the support in the bath.    
   
   
       3 . The device according to  claim 1 , further characterized in that it comprises 
 a drive means for the dielectric support, and    a succession of bath sections into and out of which the support is passed.    
   
   
       4 . The device according to  claim 3 , further characterized in that it comprises 
 a series of first rollers situated outside the bath, and a series of second rollers situated in the bath,    the dielectric support passing alternatively from a first roller to a second roller and so on,    the first rollers being supplied at the first potential,    the second rollers preferably being insulating.    
   
   
       5 . The device according to  claim 4 , further characterized in that the rollers are motorized.  
   
   
       6 . The device according to  claim 1 , further characterized in that the electrolytic bath is a formulation based on copper sulfate in acid medium.  
   
   
       7 . The device according to  claim 1 , further characterized in that the dielectric support is positioned between a first series of first electrodes and a second series of first electrodes.  
   
   
       8 . The device according to  claim 1 , further characterized in that each of these patterns are connected together by at least one connection track.  
   
   
       9 . A metallization method for a dielectric support coated with patterns of electrically conductive tracks, characterized in that 
 a—at least one conductive track pattern is subjected to an electrolytic bath by immersing the dielectric support in this bath, and by connecting the tracks in short-circuit to a source of a first electrical potential with a polarity opposite to that of a second potential to which the electrolytic bath is subjected, and    b—opposite pattern sections of the same pattern are subjected to the first potential by means of at least two electrodes, while a middle section of the pattern is immersed in the bath.    
   
   
       10 . The method according to  claim 9 , further characterized in that 
 steps a and b are repeated.    
   
   
       11 . The method according to  claim 10 , further characterized in that 
 for the repetition, the same bath is used.    
   
   
       12 . The method according to  claim 9 , further characterized in that the electrolytic bath is a formulation based on copper sulfate in acid medium.  
   
   
       13 . The method according to  claim 9 , further characterized in that 
 the steps a and b are successive in time at a rate comprised between 1 to 10 meters per minute.