	US 7,520,973 B2
	Method for regenerating etching solutions containing iron for the use in etching or pickling copper or copper alloys and an apparatus for carrying out said method
Kai-Jens Matejat, Oberkrämer (Germany); and Sven Lamprecht, Oberkrämer (Germany)
Assigned to Atotech Deutschland GmbH, (Germany)
Appl. No. 10/559,396 PCT Filed Jun. 07, 2004, PCT No. PCT/EP2004/006115 § 371(c)(1), (2), (4) Date Apr. 03, 2006, PCT Pub. No. WO2004/111308, PCT Pub. Date Dec. 23, 2004.
Claims priority of application No. 103 26 767 (DE), filed on Jun. 13, 2003.
Prior Publication US 2006/0175204 A1, Aug. 10, 2006
Int. Cl. C02F 1/46 (2006.01)

U.S. Cl. 205—687 [205/704; 205/741; 205/743; 204/272; 204/275.1]

10 Claims

1. Method for regenerating from an etching system an etching solution containing iron for the use in etching or pickling copper or copper alloys, comprising:

(i) feeding the etching solution to be regenerated from the etching system into an electrolysis cell comprising a cathode, an inert anode, means for removing the electrolytically deposited copper from the cathode and means for collecting the removed copper and applying a potential to the removed copper, wherein the electrolysis cell does not have an ion exchange membrane or a diaphragm, wherein the electrolysis cell is constructed to channel the etching solution such that the solution contacts the cathode of the electrolysis cell first, and then contacts the anode, and then exits the electrolysis cell, and wherein the electroylsis cell is a closed system which prevents gas from escaping from the solution;

(ii) electrolytically depositing the copper comprised in the etching solution at the cathode,

(iii) oxidising the Fe(II) comprised in the etching solution to Fe(III) at the anode,

(iv) removing the copper deposited at the cathode,

(v) applying a potential to the removed copper to prevent re-dissolving of the copper, and

(vi) returning the etching solution being thus treated to the etching system.