METHOD FOR STRUCTURING METAL-CERAMIC SUBSTRATES, AND STRUCTURED METAL CERAMIC SUBSTRATE

1 . A method for structuring metal-ceramic substrates, comprising the steps of:

a) providing a first metal-ceramic substrate and a second metal-ceramic substrate, each comprising

a ceramic layer,

a metal layer, and

a bonding layer located between the ceramic layer and the metal layer, wherein the bonding layer comprises (i) a metal having a melting point of at least 700° C. and (ii) an active metal,

b) providing an etching solution 1 that is capable of removing the metal from the metal layer and at least partly removing the metal having a melting point of at least 700° C. from the bonding layer,

c) providing an etching solution 2 that is capable of removing the active metal from the bonding layer,

d) masking regions on the metal layer of the first metal-ceramic substrate and on the metal layer of the second metal-ceramic substrate that are not intended to be removed,

e) contacting the first metal-ceramic substrate and the second metal-ceramic substrate with the etching solution 1, and

f) contacting the first metal-ceramic substrate and the second metal-ceramic substrate with the etching solution 2, wherein the first metal-ceramic substrate and the second metal-ceramic substrate are positioned such that an orthogonal projection of the first metal-ceramic substrate onto a projection plane parallel to the metal layer of the first metal-ceramic substrate shades no more than 60% of the metal layer of the second metal-ceramic substrate.

2 . The method according to claim 1 , wherein the ceramic of the ceramic layer is selected from the group consisting of aluminum nitride ceramics, silicon nitride ceramics and aluminum oxide ceramics.

3 . The method according to claim 1 , wherein the metal of the metal layer is copper.

4 . The method according to claim 1 , wherein the metal having a melting point of at least 700° C. is copper.

5 . The method according to claim 1 , wherein the bonding layer comprises a metal having a melting point of less than 700° C.

6 . The method according to claim 5 , wherein the metal having a melting point of less than 700° C. is selected from the group consisting of tin, bismuth, indium, gallium, zinc, antimony and magnesium.

7 . The method according to claim 1 , wherein the active metal is selected from the group consisting of titanium, zirconium, niobium, tantalum, vanadium and hafnium.

8 . The method according to claim 1 , wherein the maximum content of silver is 10.0 atomic percent and more preferably 1.0 atomic percent, based on the number of atoms in the bonding layer.

9 . The method according to claim 1 , wherein, while the first metal-ceramic substrate and the second metal-ceramic substrate are being contacted with the etching solution 2, the first metal-ceramic substrate and the second metal-ceramic substrate are positioned such that an orthogonal projection of the first metal-ceramic substrate onto a projection plane parallel to the metal layer of the first metal-ceramic substrate shades no more than 50%, preferably no more than 40%, particularly preferably no more than 30% and very particularly preferably no more than 15%, of the metal layer of the second metal-ceramic substrate.

10 . The method according to claim 1 , wherein, while being contacted with etching solution 2, the first metal-ceramic substrate and the second metal-ceramic substrate are positioned on a carrier, preferably on the same carrier.

11 . The method according to claim 10 , wherein the carrier is a conveyor belt that is moved in a conveying direction.

12 . The method according to claim 11 , wherein, while being contacted with the etching solution 2, the first metal-ceramic substrate and the second metal-ceramic substrate are positioned in at least one of the following ways:

a) the first metal-ceramic substrate and the second metal-ceramic substrate are not stacked;

b) the first metal-ceramic substrate and the second metal-ceramic substrate are arranged in a substantially horizontal position;

c) the first metal-ceramic substrate and the second metal-ceramic substrate are arranged in a substantially vertical position and one after another with respect to the conveying direction;

d) the first metal-ceramic substrate and the second metal-ceramic substrate are positioned such that the first metal-ceramic substrate and the conveying direction form an angle that is no more than 45°, more preferably no more than 30°, and even more preferably no more than 20°, and the second metal-ceramic substrate and the conveying direction form an angle that is no more than 45°, more preferably no more than 30°, and even more preferably no more than 20°.

13 . A structured metal-ceramic substrate obtainable according to claim 1 .