Method and device for electrochemical machining of substrates

Abstract

A method and a device with the aid of which a substrate is electrochemically machined, material being removed from the surface of a conductive substrate with the aid of an also conductive tool. The removal takes place as a function of the surface structure which is incorporated into the tool. The core of the present invention is that the substrate and the tool are moved toward one another during the electrochemical etching process. However, it may alternatively also be provided that either the substrate or the tool is locally stationary, while only the counterpart is moved. In a particularly preferred embodiment of the present invention, only the tool is moved toward the substrate.

1 . A method for electrochemical machining of a substrate using a conductive substrate ( 120 ,  420 ) and a conductive tool ( 100 ,  400 ), the tool having a surface structure ( 130 ), comprising:
 machining the substrate, starting with the tool, using an electrochemical etching process, and   removing material from a surface of the substrate with aid of the etching process as a function of the surface structure of the tool,   wherein the substrate and the tool are moved toward one another during the electrochemical etching process.   
   
   
       2 . The method as recited in  claim 1 , wherein the tool or the substrate remains locally stationary during the etching process, and wherein the tool is moved toward the substrate. 
   
   
       3 . The method as recited in  claim 1 , wherein material is removed from the substrate in a targeted manner with aid of the surface structure of the tool, and wherein the material is removed essentially perpendicularly to the substrate surface. 
   
   
       4 . The method as recited in  claim 3 , wherein the targeted material removal results in a separation of the substrate into a plurality of sub-substrates, and wherein the substrate is completely etched through according to its thickness. 
   
   
       5 . The method as recited in  claim 1 , wherein on a front side ( 140 ,  440 ) the substrate contains a plurality of sensor elements produced in or on the substrate, and wherein the material is removed from the substrate
 around the sensor elements or   essentially on the rear side ( 150 ,  450 ) of the substrate opposite the sensor elements.   
   
   
       6 . The method as recited in  claim 1 , wherein the surface structure of the tool has protrusions and recesses, and wherein the recesses have a depth which corresponds at least to the thickness ( 160 ) of the substrate. 
   
   
       7 . The method as recited in  claim 6 , wherein, as material removal progresses, the tool is at least partially inserted into the substrate, and wherein the protrusions are inserted into the holes in the substrate produced by the material removal. 
   
   
       8 . The method as recited in  claim 6 , wherein at least one of the current and the concentration of the electrolyte solution are varied as a function of the distance of the tool from the substrate, and wherein the distance from the recess of the tool to the substrate surface is taken into account. 
   
   
       9 . The method as recited in  claim 1 , wherein the substrate represents a first electrode and the tool represents a second electrode for the electrochemical etching process, and wherein, during the etching process, direct contact between the substrate and the tool is avoided. 
   
   
       10 . A device for electrochemical machining of a substrate according to a method recited in  claim 1 , comprising:
 a conductive substrate ( 120 ,  420 ) and   a conductive tool ( 100 ,  400 ),   the tool having a surface structure ( 130 ), wherein   the substrate is machined, starting with the tool, with aid of an electrochemical etching process, and   material is removed from the surface of the substrate with aid of the etching process as a function of the surface structure of the tool, the device further comprising   moving means for moving the substrate and the tool toward one another during the electrochemical etching process.