Method and system for forming RF reflective pathways

Abstract

The present invention provides for a system and two methods for forming RF reflective pathways. These pathways can form a radio frequency identification tag. A first method uses a thermal transfer ribbon, coated with a conductive material that is engaged with a receiver substrate. A thermal print head will heat a composition on the thermal transfer ribbon in order to transfer it to the receiver substrate. This transfer composition forms the RF reflective pathway. In an alternative method, a receiver substrate is heated in order to react conductive material thereon. This receiver substrate is also heated by a thermal print head to form a RF reflective pathway.

1 . A system for producing radio frequency tags comprising: 
 a conveyor for moving a substrate;    a thermal print head, the conveyor moving the substrate past the thermal print head, the thermal print head being selectively actuatable to heat a desired pattern on the substrate;    means on the substrate for reacting with the heat source to form RF reflective pathways, the means including a heat sensitive composition on the substrate.    
   
   
       2 . The system for producing radio frequency tags as recited in  claim 1 , wherein the substrate is a thermal transfer ribbon and wherein the conveyor further conveys a receiver substrate past the heat source, the receiver substrate and the thermal transfer ribbon being engaged at the thermal print head and the heat sensitive composition being initially provided on the thermal transfer ribbon being heated in the desired pattern by the thermal print head and thereafter being transferred to the receiver substrate, the heat sensitive composition which is not heated by the thermal print head remaining on the thermal transfer ribbon, the heat sensitive composition transferred to the receiver substrate forming RF reflective pathways on the receiver substrate.  
   
   
       3 . The system for producing radio frequency tags as recited in  claim 1 , wherein the heat sensitive composition on the substrate includes at least one of metallic inks, metallic substances, metallic salts, metallic dispersions and carbon based inks.  
   
   
       4 . The system for producing radio frequency tags as recited in  claim 1 , wherein the heat sensitive composition on the substrate is at least one of sorbitol copper formate, copper sulfate, cuprite, tenorite and silver nitrate and wherein the thermal print head only reacts with the heat sensitive composition in the desired pattern to form the RF reflective pathways with the reacted heat sensitive composition while unreacted heat sensitive composition remains on the substrate.  
   
   
       5 . A radio frequency tag produced according to a method of forming radio frequency tags, comprising the steps of: 
 providing a thermal transfer ribbon;    moving the thermal transfer ribbon past a heat source;    engaging the thermal transfer ribbon with a receiver substrate as the thermal transfer ribbon moves past the heat source;    selectively heating portions of the thermal transfer ribbon with the heat source; and    transferring a composition from the thermal transfer ribbon to the receiver substrate, the selective heating enabling a desired resonating pattern of the composition to be transferred to the receiver substrate.    
   
   
       6 . A radio frequency tag producing according to a method of forming radio frequency tags, comprising the steps of: 
 providing a substrate coated with reactive material;    moving the substrate past a heat source;    selectively heating portions of the substrate with the heat source; and    developing the reactive material on the substrate during exposure to heat from the heat source to develop a desired resonating pattern on the substrate, the reactive material forming a RF reflective material.