DE19745797A1 - Aqueous electroless gold plating solution contains a trivalent gold salt and formaldehyde - Google Patents
Aqueous electroless gold plating solution contains a trivalent gold salt and formaldehydeInfo
- Publication number
- DE19745797A1 DE19745797A1 DE1997145797 DE19745797A DE19745797A1 DE 19745797 A1 DE19745797 A1 DE 19745797A1 DE 1997145797 DE1997145797 DE 1997145797 DE 19745797 A DE19745797 A DE 19745797A DE 19745797 A1 DE19745797 A1 DE 19745797A1
- Authority
- DE
- Germany
- Prior art keywords
- gold
- formaldehyde
- gilding
- salt
- solution
- 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.)
- Granted
Links
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 title claims abstract description 32
- 239000010931 gold Substances 0.000 title claims abstract description 32
- 229910052737 gold Inorganic materials 0.000 title claims abstract description 31
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 title claims abstract description 30
- JAJIPIAHCFBEPI-UHFFFAOYSA-N 9,10-dioxoanthracene-1-sulfonic acid Chemical compound O=C1C2=CC=CC=C2C(=O)C2=C1C=CC=C2S(=O)(=O)O JAJIPIAHCFBEPI-UHFFFAOYSA-N 0.000 title claims abstract description 11
- 238000007747 plating Methods 0.000 title abstract description 13
- 239000000758 substrate Substances 0.000 claims abstract description 6
- 239000000243 solution Substances 0.000 claims description 19
- 239000007864 aqueous solution Substances 0.000 claims description 3
- BRSVJNYNWNMJKC-UHFFFAOYSA-N [Cl].[Au] Chemical compound [Cl].[Au] BRSVJNYNWNMJKC-UHFFFAOYSA-N 0.000 claims description 2
- 239000008098 formaldehyde solution Substances 0.000 claims description 2
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical group O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 claims description 2
- 150000001805 chlorine compounds Chemical class 0.000 claims 1
- 239000003638 chemical reducing agent Substances 0.000 description 5
- 239000000843 powder Substances 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 231100000167 toxic agent Toxicity 0.000 description 3
- 235000012431 wafers Nutrition 0.000 description 3
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 229910052796 boron Inorganic materials 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- XFXPMWWXUTWYJX-UHFFFAOYSA-N Cyanide Chemical compound N#[C-] XFXPMWWXUTWYJX-UHFFFAOYSA-N 0.000 description 1
- WOFVPNPAVMKHCX-UHFFFAOYSA-N N#C[Au](C#N)C#N Chemical class N#C[Au](C#N)C#N WOFVPNPAVMKHCX-UHFFFAOYSA-N 0.000 description 1
- 229930040373 Paraformaldehyde Natural products 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- UORVGPXVDQYIDP-UHFFFAOYSA-N borane Chemical class B UORVGPXVDQYIDP-UHFFFAOYSA-N 0.000 description 1
- 229910000085 borane Inorganic materials 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000004042 decolorization Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 150000002343 gold Chemical class 0.000 description 1
- IZLAVFWQHMDDGK-UHFFFAOYSA-N gold(1+);cyanide Chemical compound [Au+].N#[C-] IZLAVFWQHMDDGK-UHFFFAOYSA-N 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- FYWSTUCDSVYLPV-UHFFFAOYSA-N nitrooxythallium Chemical compound [Tl+].[O-][N+]([O-])=O FYWSTUCDSVYLPV-UHFFFAOYSA-N 0.000 description 1
- 231100000252 nontoxic Toxicity 0.000 description 1
- 230000003000 nontoxic effect Effects 0.000 description 1
- 229920002866 paraformaldehyde Polymers 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 150000003018 phosphorus compounds Chemical class 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- NNFCIKHAZHQZJG-UHFFFAOYSA-N potassium cyanide Chemical compound [K+].N#[C-] NNFCIKHAZHQZJG-UHFFFAOYSA-N 0.000 description 1
- XTFKWYDMKGAZKK-UHFFFAOYSA-N potassium;gold(1+);dicyanide Chemical compound [K+].[Au+].N#[C-].N#[C-] XTFKWYDMKGAZKK-UHFFFAOYSA-N 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 239000013638 trimer Substances 0.000 description 1
- 239000002351 wastewater Substances 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
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
- C23C18/16—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating
- C23C18/31—Coating with metals
- C23C18/42—Coating with noble metals
- C23C18/44—Coating with noble metals using reducing agents
Landscapes
- Chemical & Material Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemically Coating (AREA)
Abstract
Description
Die Erfindung betrifft eine stromlose Vergoldungslösung nach der Gattung des unabhängigen Anspruchs.The invention relates to an electroless gold plating solution the genus of independent claim.
Es ist bekannt, mittels stromloser Vergoldungslösungen, die beispielsweise Kaliumgoldcyanid oder ein Goldsalz neben Kaliumcyanid und Kaliumhydroxid sowie Borane als Reduktionsmittel enthalten, Substrate zu vergolden. Diese Lösungen liefern autokatalytisch stromlos abgeschiedene Goldfilme auf Substraten und finden großen Einsatz, um beispielsweise elektronische Teile, Wafer und Metallpulver zu vergolden. In der EP 0 225 041 B1 wird ein Vergoldungsbad beschrieben, welches das hochgiftige Goldcyanid enthält. Weiterhin ist aus der DD 244 767 A1 bekannt, Siliziumoberflächen mittels eines Vergoldungsbades mit Gold zu beschichten, wobei dieses Goldbad eine Vielzahl von teilweise hochgiftigen Verbindungen, wie beispielsweise Thalliumnitrat enthält und darüberhinaus als Reduktionsmittel Amine enthält. Diese beiden vorgenannten Lösungen besitzen den Nachteil, daß Spuren der Reduktionsmittel, beispielsweise die entstehenden Stickstoff-, Bor- oder Phosphorverbindungen sich teilweise in die abgeschiedene Goldschicht einlagern können. Dies stört insbesondere in der Sensorik oder in der Elektronik, wo hochreine Goldschichten, oft sogar nur Monolagen, benötigt werden. Darüberhinaus wirft der Einsatz hochtoxischer Verbindungen Probleme hinsichtlich Entsorgung und der Arbeitsplatzsicherheit auf. Es bestand daher die Aufgabe, eine stromlose Vergoldungslösung zu finden, die die vorgenannten Nachteile der bisher bekannten Vergoldungslösungen, insbesondere deren Verwendung von hochgiftigen Verbindungen und der durch Reduktionsmittel bedingten Verunreinigung der abgeschiedenen Goldschichten vermeidet.It is known to use electroless gold plating solutions that for example potassium gold cyanide or a gold salt alongside Potassium cyanide and potassium hydroxide as well as boranes Contain reducing agents to gold-plate substrates. This Solutions supply electrolessly deposited electrocatalytically Gold films on substrates and are widely used to for example electronic parts, wafers and metal powder to gild. EP 0 225 041 B1 describes a gold plating bath described, which contains the highly toxic gold cyanide. It is also known from DD 244 767 A1 Silicon surfaces using a gold plating bath with gold to coat, this gold bath a variety of partially highly toxic compounds, such as Contains thallium nitrate and also as Contains reducing agents amines. These two above Solutions have the disadvantage that traces of Reducing agents, for example those that arise Some nitrogen, boron or phosphorus compounds can store in the deposited gold layer. This interferes particularly in sensors or in electronics, where high-purity gold layers, often even only monolayers, are needed. In addition, the stake throws highly toxic compounds Disposal problems and job security. It therefore existed Task to find an electroless gold plating solution that the aforementioned disadvantages of the previously known Gilding solutions, especially their use by highly toxic compounds and those caused by reducing agents conditional contamination of the deposited gold layers avoids.
Erfindungsgemäß wird eine Vergoldungslösung zum Vergolden von Materialien, beispielsweise keramische und metallische Pulver, Polymere, oder Oberflächen, wie beispielsweise Si- Wafern oder Kunststoffsubstrate, verwendet, die mindestens ein dreiwertiges Goldsalz enthält. Darüberhinaus ist nur die Verwendung von Formaldehyd vorgesehen. Damit wird ein sehr einfach zusammengesetztes Vergoldungsbad zur Verfügung gestellt, welches weiterhin vermeidet, daß durch den Einsatz bor-, stickstoff- oder phosphorhaltiger Reduktionsmittel störende Fremdatome in der Goldschicht mitabgeschieden werden. Außerdem gestaltet sich die Entsorgung der Vergoldungslösung nach Gebrauch besonders einfach, da nur ungiftige Verbindungen zum Einsatz kommen.According to the invention, a gilding solution is used for gilding of materials, for example ceramic and metallic Powders, polymers, or surfaces, such as Si Wafers or plastic substrates, used at least contains a trivalent gold salt. Furthermore, only that Use of formaldehyde is provided. This will be a very simply composed gilding bath available posed, which further avoids that through the use Reducing agents containing boron, nitrogen or phosphorus interfering foreign atoms also deposited in the gold layer become. In addition, the disposal of the Gilding solution especially easy after use, because only non-toxic compounds are used.
Vorteilhafte Ausgestaltungen und Weiterbildungen der Erfindung sind in der Unteransprüchen beschrieben.Advantageous refinements and developments of Invention are described in the subclaims.
Besonders bevorzugt wird eine dreiwertiges Gold-Chlor- Verbindung ist, insbesondere HAuCl4, welches kommerziell leicht erhältlich und kostengünstig ist eingesetzt. Die Nachteile von Gold-Cyanidverbindungen, insbesondere deren Toxizität und aufwendige Entsorgung cyanidhaltiger Abwässer werden dadurch vorteilhaft vermieden.A trivalent gold-chlorine compound is particularly preferred, in particular HAuCl 4 , which is commercially available and inexpensive. The disadvantages of gold cyanide compounds, in particular their toxicity and complicated disposal of waste water containing cyanide, are advantageously avoided in this way.
In einer besonders vorteilhaften Ausgestaltung der Vergoldungslösung werden 2 bis 20 g/l berechnet als elementares Gold des Goldsalzes sowie 40 bis 100 g/l Formaldehyd eingesetzt. Dies ermöglicht eine gezielte Variation der abzuscheidenden Schichtdicke und der Geschwindigkeit, mit der die Goldschicht abgeschieden werden kann. Es ist insbesondere vorteilhaft, 8 bis 12 g/l berechnet als elementares Gold des Goldsalzes und 60 bis 80 g/l Formaldehyd einzusetzen, so daß die Abscheidung besonders schnell von statten geht.In a particularly advantageous embodiment of the Gold plating solution are calculated as 2 to 20 g / l elemental gold of the gold salt and 40 to 100 g / l Formaldehyde used. This enables targeted Variation of the layer thickness to be deposited and the The speed at which the gold layer is deposited can. It is particularly advantageous to 8 to 12 g / l calculated as elemental gold of the gold salt and 60 to Use 80 g / l formaldehyde, so that the separation goes particularly quickly.
Vorteilhafterweise wird Formaldehyd in Form seiner 37%igen wäßrigen Lösung eingesetzt, welches handelsüblich erhältlich ist und damit einfach gehandhabt werden kann, wenngleich es auch möglich ist, Formaldehyd in fester Form einzusetzen, welches als Paraformaldehyd in Form seines Trimeren ebenfalls einfach dosierbar und kommerziell leicht erhältlich ist.Advantageously, formaldehyde is in the form of its 37% aqueous solution used, which is commercially available is available and can be easily handled, although it is also possible to use formaldehyde in solid form use which as paraformaldehyde in the form of its Trimers are also easy to dose and commercially easy is available.
Es ist möglich, daß die Vergoldung mit der erfindungsgemäßen Vergoldungslösung bei Raumtemperatur abläuft, in besonders bevorzugter Ausgestaltung findet die Vergoldung jedoch bei einer Temperatur von 20°C bis 90°C statt, vorzugsweise von 60°C bis 80°C. Durch dieses Temperaturintervall, welches besonders bevorzugt ist, wird eine schnellere Abscheidung erreicht. Damit können die Substrate besonders schnell beschichtet werden.It is possible that the gilding with the invention Gilding solution expires at room temperature, in particular however, the gold plating is preferred a temperature of 20 ° C to 90 ° C instead of, preferably 60 ° C to 80 ° C. Through this temperature interval, which faster deposition is particularly preferred reached. This allows the substrates to be particularly quick be coated.
Es ist auch möglich, daß das Formaldehyd in Form seiner wäßrigen Lösung zu der Goldlösung während des Vergoldens zuzugegeben. Damit kann eine langsamere, jedoch kontrolliertere Abscheidung der Goldschicht erreicht werden, so daß insbesondere die Dicke der Goldschicht besonders einfach eingestellt werden kann.It is also possible that the formaldehyde is in the form of its aqueous solution to the gold solution during gold plating admitted. This can make it slower, however more controlled deposition of the gold layer can be achieved, so in particular the thickness of the gold layer especially can be easily adjusted.
In einer besonders bevorzugten Ausgestaltung, werden 5 g HAuCl4, entsprechend 2,5 g Au und 50 ml einer 37%igen Formaldehydlösung in ein Gefäß gebracht und anschließend auf 250 ml Lösung mit Wasser aufgefüllt. In dieses Bad wird ein hochreines Platinpulver, welches in der Sensorik, insbesondere zum Drucken von Leiterbahnen verwendet wird, eingebracht. Die vollständige Umsetzung des Bades kann an dessen vollständiger Entfärbung leicht verfolgt werden. Anschließend wird das derart vorlegierte Platinpulver, welches nunmehr eine Goldschicht aufweist, abfiltriert und getrocknet. Diese Platinpulver zeichnen sich nach dem Vergolden durch eine verkürzte Temperzeit bis zur vollständigen Legierungsbildung aus, was dazu führt, daß beispielsweise aktivere Elektroden, beispielsweise bei einem Einsatz als Elektrode für Gassensoren, erhalten werden können.In a particularly preferred embodiment, 5 g of HAuCl 4 , corresponding to 2.5 g of Au and 50 ml of a 37% formaldehyde solution, are placed in a vessel and then made up to 250 ml of solution with water. A high-purity platinum powder, which is used in sensors, in particular for printing conductor tracks, is introduced into this bath. The complete implementation of the bath can easily be followed by its complete decolorization. The platinum powder which has been alloyed in this way and which now has a gold layer is then filtered off and dried. After gold plating, these platinum powders are distinguished by a shortened annealing time until the alloy has completely formed, which means that, for example, more active electrodes can be obtained, for example when used as an electrode for gas sensors.
Selbstverständlich stellt das Ausführungsbeispiel keine Beschränkung der Erfindung dar. Es ist erfindungsgemäß ebenso möglich andere Pulver, beispielsweise metallische und keramische Pulver mit dem erfindungsgemäßen Bad zu vergolden, oder auch Oberflächen, beispielsweise Siliziumwafer mit einer feinen Goldschicht zu überziehen.Of course, the exemplary embodiment does not constitute one Limitation of the invention. It is according to the invention other powders, for example metallic and ceramic powder with the bath according to the invention gild, or surfaces, for example To coat silicon wafers with a fine gold layer.
Claims (7)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE1997145797 DE19745797C2 (en) | 1997-10-16 | 1997-10-16 | Solution and method for electroless gold plating |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE1997145797 DE19745797C2 (en) | 1997-10-16 | 1997-10-16 | Solution and method for electroless gold plating |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| DE19745797A1 true DE19745797A1 (en) | 1999-04-22 |
| DE19745797C2 DE19745797C2 (en) | 2001-11-08 |
Family
ID=7845762
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DE1997145797 Expired - Fee Related DE19745797C2 (en) | 1997-10-16 | 1997-10-16 | Solution and method for electroless gold plating |
Country Status (1)
| Country | Link |
|---|---|
| DE (1) | DE19745797C2 (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DD244767A1 (en) * | 1985-12-24 | 1987-04-15 | Liebknecht Mikroelektron | PROCESS FOR GILDING SI SURFACES |
| EP0225041B1 (en) * | 1985-10-25 | 1990-01-03 | C. Uyemura & Co Ltd | Electroless gold plating solution |
| US5380562A (en) * | 1991-02-22 | 1995-01-10 | Okuno Chemical Industries Co., Ltd. | Process for electroless gold plating |
| US5650202A (en) * | 1996-07-18 | 1997-07-22 | The United States Of America As Represented By The Secretary Of The Army | Method for forming a platinum coating on non-coductive substrates such as glass |
-
1997
- 1997-10-16 DE DE1997145797 patent/DE19745797C2/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0225041B1 (en) * | 1985-10-25 | 1990-01-03 | C. Uyemura & Co Ltd | Electroless gold plating solution |
| DD244767A1 (en) * | 1985-12-24 | 1987-04-15 | Liebknecht Mikroelektron | PROCESS FOR GILDING SI SURFACES |
| US5380562A (en) * | 1991-02-22 | 1995-01-10 | Okuno Chemical Industries Co., Ltd. | Process for electroless gold plating |
| US5650202A (en) * | 1996-07-18 | 1997-07-22 | The United States Of America As Represented By The Secretary Of The Army | Method for forming a platinum coating on non-coductive substrates such as glass |
Also Published As
| Publication number | Publication date |
|---|---|
| DE19745797C2 (en) | 2001-11-08 |
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| OP8 | Request for examination as to paragraph 44 patent law | ||
| D2 | Grant after examination | ||
| 8364 | No opposition during term of opposition | ||
| 8339 | Ceased/non-payment of the annual fee |