GB2163101A - Etching of copper films on circuit boards - Google Patents
Etching of copper films on circuit boards Download PDFInfo
- Publication number
- GB2163101A GB2163101A GB08518145A GB8518145A GB2163101A GB 2163101 A GB2163101 A GB 2163101A GB 08518145 A GB08518145 A GB 08518145A GB 8518145 A GB8518145 A GB 8518145A GB 2163101 A GB2163101 A GB 2163101A
- Authority
- GB
- United Kingdom
- Prior art keywords
- etching
- copper
- etching solution
- solution
- circuit boards
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000005530 etching Methods 0.000 title claims abstract description 81
- 239000010949 copper Substances 0.000 title claims abstract description 58
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 title claims abstract description 40
- 229910052802 copper Inorganic materials 0.000 title claims abstract description 40
- 239000003054 catalyst Substances 0.000 claims abstract description 30
- 239000000126 substance Substances 0.000 claims abstract description 21
- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 claims abstract description 16
- WKBOTKDWSSQWDR-UHFFFAOYSA-N Bromine atom Chemical compound [Br] WKBOTKDWSSQWDR-UHFFFAOYSA-N 0.000 claims abstract description 15
- 229910052794 bromium Inorganic materials 0.000 claims abstract description 15
- SWLVFNYSXGMGBS-UHFFFAOYSA-N ammonium bromide Chemical compound [NH4+].[Br-] SWLVFNYSXGMGBS-UHFFFAOYSA-N 0.000 claims abstract description 3
- 239000000243 solution Substances 0.000 claims description 43
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 36
- 238000000034 method Methods 0.000 claims description 21
- 229910000069 nitrogen hydride Inorganic materials 0.000 claims description 16
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 claims description 5
- 229910052921 ammonium sulfate Inorganic materials 0.000 claims description 5
- 235000011130 ammonium sulphate Nutrition 0.000 claims description 5
- 238000011084 recovery Methods 0.000 claims description 5
- 229910021529 ammonia Inorganic materials 0.000 claims description 2
- 239000012266 salt solution Substances 0.000 claims description 2
- CPELXLSAUQHCOX-UHFFFAOYSA-M Bromide Chemical compound [Br-] CPELXLSAUQHCOX-UHFFFAOYSA-M 0.000 claims 2
- 241000272168 Laridae Species 0.000 claims 2
- 229910006130 SO4 Inorganic materials 0.000 claims 1
- 229910000831 Steel Inorganic materials 0.000 abstract description 2
- 239000010959 steel Substances 0.000 abstract description 2
- 238000007792 addition Methods 0.000 description 9
- 239000007921 spray Substances 0.000 description 4
- 238000000926 separation method Methods 0.000 description 3
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 150000001768 cations Chemical class 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000018109 developmental process Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005868 electrolysis reaction Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 230000008929 regeneration Effects 0.000 description 2
- 238000011069 regeneration method Methods 0.000 description 2
- GPPXJZIENCGNKB-UHFFFAOYSA-N vanadium Chemical compound [V]#[V] GPPXJZIENCGNKB-UHFFFAOYSA-N 0.000 description 2
- 229910052720 vanadium Inorganic materials 0.000 description 2
- LSTRKXWIZZZYAS-UHFFFAOYSA-N 2-bromoacetyl bromide Chemical compound BrCC(Br)=O LSTRKXWIZZZYAS-UHFFFAOYSA-N 0.000 description 1
- ILLHORFDXDLILE-UHFFFAOYSA-N 2-bromopropanoyl bromide Chemical compound CC(Br)C(Br)=O ILLHORFDXDLILE-UHFFFAOYSA-N 0.000 description 1
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 1
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- LZZYPRNAOMGNLH-UHFFFAOYSA-M Cetrimonium bromide Chemical compound [Br-].CCCCCCCCCCCCCCCC[N+](C)(C)C LZZYPRNAOMGNLH-UHFFFAOYSA-M 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- ORTQZVOHEJQUHG-UHFFFAOYSA-L copper(II) chloride Chemical compound Cl[Cu]Cl ORTQZVOHEJQUHG-UHFFFAOYSA-L 0.000 description 1
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000005187 foaming Methods 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 239000003350 kerosene Substances 0.000 description 1
- 238000000622 liquid--liquid extraction Methods 0.000 description 1
- 231100000614 poison Toxicity 0.000 description 1
- 230000007096 poisonous effect Effects 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000001172 regenerating effect Effects 0.000 description 1
- 238000012958 reprocessing Methods 0.000 description 1
- 238000000638 solvent extraction Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000001117 sulphuric acid Substances 0.000 description 1
- 235000011149 sulphuric acid Nutrition 0.000 description 1
- 150000003682 vanadium compounds Chemical class 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F1/00—Etching metallic material by chemical means
- C23F1/46—Regeneration of etching compositions
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F1/00—Etching metallic material by chemical means
- C23F1/10—Etching compositions
- C23F1/14—Aqueous compositions
- C23F1/32—Alkaline compositions
- C23F1/34—Alkaline compositions for etching copper or alloys thereof
Landscapes
- Chemical & Material Sciences (AREA)
- Metallurgy (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Chemistry (AREA)
- ing And Chemical Polishing (AREA)
- Manufacturing Of Printed Circuit Boards (AREA)
- Catalysts (AREA)
- Manufacturing Of Printed Wiring (AREA)
- Electrolytic Production Of Metals (AREA)
- Chemically Coating (AREA)
Abstract
Copper films on circuit boards are etched using a solution containing [Cu(NH3)4]SO4, NH3 and (NH4)2 SO4, wherein the etching solution additionally contains a substance containing bromine as the catalyst increasing the etching velocity, such as NH4Br, CH3CHBrCOBr Br2, KBr, C19 H42 BrN, or C2H2Br2O. From such an etching solution it is possible to separate electrolytically ductile copper as a cohesive layer which can be easily removed from high-quality steel electrodes.
Description
SPECIFICATION
A process for the etching of copper films on circuit boards
The invention relates to a process for the etching of copper films on circuit boards along with the electrolytical recovery of copper from the etching solution, as described in the introductory part of Claim 1.
The processes mainly used industrially today for the etching of circuit boards use as the etching solution a concentrated aqueous solution of [Cu(NH3)4]Cl2 and NH3. The bivalent copper contained in this solution oxidises the metallic copper of the exposed sections of the thin copper layer on the circuit board into univalent copper, during which process it is itself also converted into the univalent state. The univalent copper contained in the salt solution is re-oxidised by atmospheric oxygen into bivalent copper, which is then again available for further etching.
After prolonged use of the etching solution the copper content thereof has to be reduced again, which cannot be effected by electrolytical separation since Cl2 would be simultaneously released during this process. The copper is therefore fixed by liquid-liquid extraction to a ss-diketone which is dissolved in kerosene and which is itself not soluble in water; subsequently, the copper is split off again from this p-diketone by using sulphuric acid, during which process copper sulphate is obtained. The latter can then be electrolysed in the usual way with the formation of metallic copper.
The above-described reprocessing method for the etching solution is complicated and can only be performed in a chemical establishment equipped for this purpose and to which used-up etching solutions have to be returned by the circuit board manufacturer.
It is indeed also possible to etch circuit boards with a concentrated aqueous [Cu(NH3)4]SO4 solution. The copper additionally dissolved during etching can be electrolytically separated from sudh a solution without any difficulties. However, if such an etching solution is used, the etching times are considerably longer than those obtained if a concentrated copper chloride/ammonia solution is used.
In order to shorten the etching time necessary if a [Cu(NH3)4]SO4solution is used, it has been proposed in the previous Application P 33 05 319.7 to add to the concentrated [Cu(NH3)4]SO4 solution a catalyst, namely vanadium or a vanadium compound. The electrolytically separated copper from vanadiferous [Cu(NH3)4]SO4 etching solutions is however not cohesive, tends to crumble and is difficult to remove from the electrode used for the sepa ration. Furthermore, the efficiency of the electrolysis drops as the thickness of the separated copper layer increases.
It is the object of the present invention to provide a process for the etching of copper films on circuit boards with the electrolytic full regeneration of a [Cu(NH3)4jSO4 etching solution where one obtains cohesive
Cu layers during the electrolytic copper recovery, while the etching continues however to be accelerated catalytically.
According to the invention, this problem is solved by a process according to Claim 1.
In the process according to the invention, there is used with the substance containing bromine a catalyst which is not present as a cation in the etching solution and is thus not separated together with the copper during the electrolytic recovery thereof. Presumably, the low mechanical strength of copper separated from vanadiferous [Cu(NH3)4]S04 etching solutions is due to the incorporation of vanadium in the separated copper. The substance containing bromine used as the catalyst according to the invention does not form any cation and can therefore not be separated together with the copper; there informed a pure ductile copper layer. Catalyst substances containing bromine are also favourable as far as costs are concerned.
Advantageous developments of the invention are given in the Sub-Claims.
The invention will hereinafter be explained in more detail with reference to the drawing. Therein, the sole figure shows a diagrammatical representation of a system for the continuous etching of printed circuit boards along with the continuous regeneration of the etching solution by way of electrolytical separation of copper from the etching solution.
In the drawing, an elongated box 10 is reproduced in a transversal section. A lower portion of the box 10 serves as the etching solution sump 12. The latter is connected via a line 14to the suction side of a pump 16.
The outlet side of the latter is connected to a lower spray tube 18 and an upper spray tube 20.
Between the spray tubes 18, 20 there extends a permeable endless conveyor 22 which continuously moves circuit boards 24 through the box 10 perpendicularly to the drawing plane. The circuit boards 24 have on at least one of their surfaces a continuous copper film, over which a photo-sensitive protective film (photo-resist) has been applied. Partial areas of the latter have been detached by exposure and subsequent development so that only those areas of the copper film are still covered which are to form circuit boards later. The other areas of the copper film are exposed and are subjected to the etching solution rays 26 emitted by the spray tubes 18,20.
The etching solution contains in the fresh composition 1.227 mol/l [Cu(NH3)4]SO4, 0.01 to 0.6 mol/l free NH3 as well as 0.606 mol/l (NH4)2SO4. The temperature of the etching solution is between 323 and 325 K (50-52 C). Additionally, the etching solution contains a substance containing bromine as the catalyst increasing the etching velocity, which will be described in more detail later.
Within a time of somewhat less than 1 minute, the etching solution dissolves out completely the free areas of the copper film at a thickness of the latter of 35im, there being formed initially according to the equation
Cu + Cu2+e2 Cu+ univalent copper.The latter is re-oxidised by atmospheric oxygen so that one obtains for the etching operation as a whole the following reaction equation:
2 Cu + 4 NH2 + 2 (NH4)2SO4 + O2 o2 [Cu(NH3)4jSO4 + 2 H20 (1)
On account of the etching operation, the copper concentration of the etching solution is thus increased in the course of time; for regenerating the etching solution an appropriate quantity of the copper has to be removed from the etching solution
For this purpose, the box 10 is connected via another line 27 to an electrolytic cell 28, in which there are provided a cathode 30 and an anode 32 which are connected to a supply not shown.On account of the impressed electrolytic voltage, the equation (1) indicated above occurs in the electrolytic cell 28 in exactly the opposite direction so that the content of free ammonia and (NH4)2SO4 increases in the etching solution. The catalyst substance containing bromine, which is also contained in the etching solution, is not affected by the electrolysis and is pumped back, together with the etching solution into the box 10 by way of another pump 34 and a line 36.
The copper deposited electrolytically on the cathode 30 is a cohesive ductile layer which can be easily stripped mechanically from the cathodes made of high-quality steel.
Hereinafter there will be given some examples of catalyst substances containing bromine and increasing the etching velocity as well of the etching velocities obtained therewith.
For each trial there was used an etching solution having the basic composition indicated further above and the indicated temperature.
Example 1:
Use of KBr as the catalyst substance containing bromine.
The following table gives a survey of the concentration of the catalyst substance, the pH-value of the etching solution at 323-325 K as well as the time required for etching through a 35 Fm thick Cu film.
Catalyst
addition (ugli) pH-value etching time (s) 0 8.79 98
0.5 8.79 68
1.0 8.79 63
2.0 8.79 57
2.0 9.25 60
2.0 9.1 58
3.0 9.25 50
3.0 9.1 47
4.0 9.2 46
4.0 8.8 44
6.0 8.9 46
One realises that the etching time can be halved by the catalyst addition.
Example 2:
Use of NH4Br as the catalyst substance.
The following table again gives a survey of the etching velocity obtained.
Catalyst
addition (girl) pH-value etching time Isl 0 8.9 96
0.1 8.9 68
1.0 8.9 53
3.0 8.9 50
4.0 8.9 49
6.0 8.9 49
8.0 8.9 49
Example 3:
Use of bromine (ultra-pure) as the catalyst substance.
Because of a violent reaction, pure bromine can only be used in a considerably diluted form, dissolved in chloroform (MAC-value = 0.1 ppm). One obtains the following etching velocities:
Catalyst
addition mills pH-value etching time (s) 0 8.84 112
0 9.04 107
0.1 9.0 62
0.5 9.03 55
0.8 9.03 43
1.45 9.03 40
2.0 9.03 40
Example 4:
Use of N-cetyl-N,N,N-trimethylammonium bromide (C1gH42BrN) as the catalyst substance.
If this catalyst substance is employed, there should be taken additional measures which counteract any foaming of the etching solution during spraying. The following etching results are obtained:
Catalyst
addition (girl) pH-value etching time (sl 0 9.0 103
0.1 9.0 90
0.5 9.0 62
1.0 9.0 62
2.0 9.0 72
4.0 9.0 78
Example 5:
Use of bromoacetyl bromide (C2H2Br2O) as the catalyst substance.
If this catalyst substance, which is readily volatile and poisonous, is used, appropriate precautions have to be taken. The following etching results are obtained:
Catalyst
addition (mill) pH-value etching time (s) 0 8.55 98
0.9 8.55 49
1.8 8.55 47
2.0 8.55 46
3.0 8.9 45
5.0 8.9 48
7.0 8.9 50
Example 6:
Use of 2-bromopropionic acid bromide (CH3-CHBrCOBr) as the catalyst substance.
The following etching results are obtained:
Catalyst
addition (mlii) pH-value etching time (s) 0 8.27 105
1.0 8.27 51
2.0 8.10 49
2.0 8.7 48
3.0 8.94 47
3.0 9.48 44
4.0 9.4 40
4.0 9.3 37
4.0 9.35 39
5.0 9.35 38
7.0. 9.35 39
10.0 9.35 38
It is to be noted from the above examples that the etching velocity can be initially increased by increasing the catalyst addition but that, starting with additions of approximately 4 g/l of active bromine, there occurs a
Saturation; a further increase of the catalyst concentration does not lead to any important increase of the etching velocity.
It is also evident from the above examples that the etching velocity additionaly depends on the pH-value of the etching solution. Here is another example to this effect, which relates to the etching time for a 35pom thick
Cu layer at 325-326 K (52-53, C), the etching solution containing for the rest 1.369 mol/l [Cu(NH3)4jSO4 as well as 0.606 mol/l (NH4)2SO4 (this value is reduced following the "etching-in" by the formation of [Cu(NH3)4SO4.
The etching solution used contained respectively 3.3 g Br/I.
pH-valùe free NH3 (moll) etching time (s) 8.75 0.01 53
8.8 0.061 51
8.95 0.151 50
9.05 0.271 51
9.3 0.541 53
9.3 0.641 50
9.45 0.871 59
9.75 1.621 68
Of the catalyst substance examples given further above the examples 2 and 6 are preferred since the respective catalyst substances are easy to handle, are free of any undesirable side-effects and ensure a good increase of the etching velocity.
Claims (10)
1. A process for the etching of copper films on circuit boards along with the electrolytical recovery of copper from the etching solution, wherein an etching solution of [Cu(NH3)4]SO4,NH3 and (NH4)2SO4, which additionally contains a catalyst increasing the etching velocity, is brought into contact with the circuit boards, the etched copper is separated electrolytically from the etching solution and the thus regenerated salt solution is returned into the process, characterised in that the etching solution contains as the catalyst a substance containing bromine.
2. A process as claimed in Claim 1, characterised inthatthe concentration of catalytically active bromine is 0.1-8 gull.
3. A process as claimed in Claim 2, characterised in that the concentration of catalytically active bromine is 1-4 gull.
4. A process as claimed in one of Claims 1 to 3, characterised in that the substance containing bromine is a bromide.
5. A process as claimed in Claim 4, characterised in that the bromide is NH4Br or CH3CHBrCOBr.
6. A process as claimed in one of Claims 1 to 5, characterised in that the etching is carried out at a temperature of the etching solution of 318-328 K (45-55, C).
7. A process as claimed in one of Claims 1 to 6, characterised in that the etching is carried out at a pH-value of the etching solution of 8.2-9.5, measured at a temperature of the solution of 327 K (54 C).
8. A process as claimed in one of Claims 1 to 6, characterised in that the concentration of the free ammonia is between 0.01 and 1.0 mol/l.
9. A process as claimed in one of Claims 1 to 8, characterised in that the Cu2+ concentration of the etching solution is 70-120 g/l.
10. The process for the etching of copper films on circuit boards along with the electrolytical recovery of copper from the etching solution substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing and by reference to the examples set forth.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19843429902 DE3429902A1 (en) | 1984-08-14 | 1984-08-14 | METHOD FOR ETCHING COPPER FILMS ON BOARDS UNDER ELECTROLYTIC RECOVERY OF COPPER FROM THE ACET SOLUTION |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB8518145D0 GB8518145D0 (en) | 1985-08-21 |
| GB2163101A true GB2163101A (en) | 1986-02-19 |
Family
ID=6243027
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08518145A Withdrawn GB2163101A (en) | 1984-08-14 | 1985-07-18 | Etching of copper films on circuit boards |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS61106782A (en) |
| AT (1) | AT387590B (en) |
| BE (1) | BE903054A (en) |
| BR (1) | BR8503833A (en) |
| DE (1) | DE3429902A1 (en) |
| FR (1) | FR2569205A1 (en) |
| GB (1) | GB2163101A (en) |
| IT (1) | IT1185341B (en) |
| NL (1) | NL8502245A (en) |
| SE (1) | SE8503594L (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1992001086A1 (en) * | 1990-07-05 | 1992-01-23 | Elo-Chem Ätztechnik Gmbh | Etching solution |
| EP0704557A1 (en) * | 1994-09-08 | 1996-04-03 | Ecochem Aktiengesellschaft | Improved process for heavy metals electrowinning |
| EP0722512A4 (en) * | 1993-09-08 | 1996-07-31 | ||
| WO2007055669A3 (en) * | 2005-11-10 | 2007-11-01 | Eve Recycling Sarl | Recyclable etching solution |
| WO2012171209A1 (en) * | 2011-06-17 | 2012-12-20 | Empire Technology Development Llc | Reclaiming metal from articles |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3324450A1 (en) * | 1983-07-07 | 1985-01-17 | ELO-CHEM Ätztechnik GmbH, 7758 Meersburg | AMMONIUM SULFATE-CONTAINING ETCH SOLUTION AND METHOD FOR REGENERATING THE ETCH SOLUTION |
| DE3340342A1 (en) * | 1983-11-08 | 1985-05-15 | ELO-CHEM Ätztechnik GmbH, 7758 Meersburg | METHOD AND PLANT FOR REGENERATING AN AMMONIA ACID SOLUTION |
-
1984
- 1984-08-14 DE DE19843429902 patent/DE3429902A1/en not_active Withdrawn
-
1985
- 1985-07-18 GB GB08518145A patent/GB2163101A/en not_active Withdrawn
- 1985-07-25 SE SE8503594A patent/SE8503594L/en not_active Application Discontinuation
- 1985-07-31 IT IT21796/85A patent/IT1185341B/en active
- 1985-08-09 JP JP60174390A patent/JPS61106782A/en active Pending
- 1985-08-12 BE BE6/48129A patent/BE903054A/en not_active IP Right Cessation
- 1985-08-13 NL NL8502245A patent/NL8502245A/en not_active Application Discontinuation
- 1985-08-13 FR FR8512442A patent/FR2569205A1/en not_active Withdrawn
- 1985-08-13 BR BR8503833A patent/BR8503833A/en unknown
- 1985-08-13 AT AT0235785A patent/AT387590B/en not_active IP Right Cessation
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1992001086A1 (en) * | 1990-07-05 | 1992-01-23 | Elo-Chem Ätztechnik Gmbh | Etching solution |
| US6129858A (en) * | 1990-07-05 | 2000-10-10 | Elo-Chem Atztechnik Gmbh | Etching solution |
| EP0722512A4 (en) * | 1993-09-08 | 1996-07-31 | ||
| EP0704557A1 (en) * | 1994-09-08 | 1996-04-03 | Ecochem Aktiengesellschaft | Improved process for heavy metals electrowinning |
| US5534131A (en) * | 1994-09-08 | 1996-07-09 | Ecochem Aktiengesellschaft | Process for heavy metals electrowinning |
| AU692277B2 (en) * | 1994-09-08 | 1998-06-04 | Ecochem Aktiengesellschaft | Improved process for heavy metals electrowinning |
| WO2007055669A3 (en) * | 2005-11-10 | 2007-11-01 | Eve Recycling Sarl | Recyclable etching solution |
| WO2012171209A1 (en) * | 2011-06-17 | 2012-12-20 | Empire Technology Development Llc | Reclaiming metal from articles |
| US8840773B2 (en) | 2011-06-17 | 2014-09-23 | Empire Technology Development LLP | Reclaiming metal from articles |
Also Published As
| Publication number | Publication date |
|---|---|
| BE903054A (en) | 1985-12-02 |
| BR8503833A (en) | 1986-05-27 |
| GB8518145D0 (en) | 1985-08-21 |
| FR2569205A1 (en) | 1986-02-21 |
| SE8503594L (en) | 1986-02-15 |
| DE3429902A1 (en) | 1986-02-27 |
| ATA235785A (en) | 1988-07-15 |
| JPS61106782A (en) | 1986-05-24 |
| NL8502245A (en) | 1986-03-03 |
| SE8503594D0 (en) | 1985-07-25 |
| IT8521796A0 (en) | 1985-07-31 |
| IT1185341B (en) | 1987-11-12 |
| AT387590B (en) | 1989-02-10 |
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