US3300328A - Electroless plating of gold - Google Patents

Electroless plating of gold Download PDF

Info

Publication number
US3300328A
US3300328A US32312763A US3300328A US 3300328 A US3300328 A US 3300328A US 32312763 A US32312763 A US 32312763A US 3300328 A US3300328 A US 3300328A
Authority
US
Grant status
Grant
Patent type
Prior art keywords
gold
plating
electroless
hydrazine
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.)
Expired - Lifetime
Application number
Inventor
Betty M Luce
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Imperial Clevite Inc
Clevite Corp
Original Assignee
Clevite Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Grant date

Links

Images

Classifications

    • GPHYSICS
    • G06COMPUTING; CALCULATING; COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F7/00Methods or arrangements for processing data by operating upon the order or content of the data handled
    • G06F7/38Methods or arrangements for performing computations using exclusively denominational number representation, e.g. using binary, ternary, decimal representation
    • G06F7/48Methods or arrangements for performing computations using exclusively denominational number representation, e.g. using binary, ternary, decimal representation using non-contact-making devices, e.g. tube, solid state device; using unspecified devices
    • G06F7/50Adding; Subtracting
    • G06F7/505Adding; Subtracting in bit-parallel fashion, i.e. having a different digit-handling circuit for each denomination
    • G06F7/509Adding; Subtracting in bit-parallel fashion, i.e. having a different digit-handling circuit for each denomination for multiple operands, e.g. digital integrators
    • G06F7/5095Adding; Subtracting in bit-parallel fashion, i.e. having a different digit-handling circuit for each denomination for multiple operands, e.g. digital integrators word-serial, i.e. with an accumulator-register
    • CCHEMISTRY; METALLURGY
    • C23COATING 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
    • C23CCOATING 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
    • C23C18/00Chemical 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
    • C23C18/16Chemical 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
    • C23C18/31Coating with metals
    • C23C18/42Coating with noble metals
    • C23C18/44Coating with noble metals using reducing agents

Description

United States Patent Ofitice 3,300,328 Patented Jan. 24, 11967 3,300,328 ELECTROLESS PLATING OF GOLD Betty M. Luce, Willowick, Ohio, assignor to Clevite Corporation, a corporation of Ohio No Drawing. Filed Nov. 12, 1963, Ser. No. 323,127 15 Claims. (Cl. 117-47) This invention relates to coating of base materials with a relatively thin layer of gold by means of electroless deposition, sometimes referred to as chemical plating.

As is well known, electroless plating in its broadest aspects involves the immersion of abase material in a plating bath and the consequent deposition of a layer of film of the plating metal on the base by means of chemical reaction and without the use of externally applied electrical energy. The chemical reaction taking place is an autocatalytic reduction of metal ions in the aqueous plating bath. In some cases, the base material is flashed or mirrored to coat it with an extremely thin layer of some metal which acts as a sensitizer to initiate the reduction reaction and/ or promote adherence of the electroless deosit.

p The electroless technique has several advantages over electroplating. One of the most important of these is the fact that it produces a uniform plating thickness on even the most intricate shapes whereas electroplating does not throw well into niches and crevices. Among the other advantages of electroless plating are the simplicity of the required apparatus engendered by the elimination of electrical equipment, and the relative ease of plating non-conductive base material such as plastic films.

While there has been considerable activity in recent years directed toward the application of the electroless plating principle to a wide variety of metals, the only commercially satisfactory processes evolved to date, insofar as is known, are for the plating of nickel, cobalt, and copper. Practical success with other metals heretofore has been nil or highly limited. Typical disadvantages characterizing the processes heretofore devised are extremely slow deposition rate, coatings of unsatisfactory integrity and/or adherence, and instability of the plating baths resulting in lack of controllability of the'deposition and rapid depletion of the bath.

It has now been found that metallic gold may be plated onto a metallic or a non-metallic substrate by a method of electroless plating which enables the production of dense, smooth, adherent gold coatings at higher deposition rates than heretofore possible. Moreover, compositions have been developed for the electroless plating of gold from aqueous solution which are relatively quite stable and permit close control and reducibility of the platings produced.

To the accomplishment of the foregoing related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the appended claims, the following description setting forth in detail certain illustrative embodiments of the invention,

such disclosed means constituting, however, but a few of gold at the interface between thesubstrate and the aquegrams per liter).

ous solution is effected by a reducing agent which is selected from the group consisting of hydrazine, alkyl hydrazines in which the alkyl group contains from one to three carbon atoms, hydroxylamine and alkyl hydroxylamines in which the alkyl group contains from 1 to 3 carbon atoms. These aqueous solutions are quite unstable in the absence of a stabilizing agent, and it has been found that the cycloaliphatic amines are a particularly satisfactory class of materials for this purpose.

The term alkali metal as used herein means sodium, potassium, and lithium.

The quality of the plate of the present invention is enhanced during use by agitation of the bath, and particularly utilization of mechanical stirring means which prevents local over-heating of the aqueous electroless gold plating bath.

The plating solutions of the present invention may be contained in any suitable vessel preferably non-metallic, e.g., glass, and the base material or article to be plated suspended by any suitable means such as a clamp, mounting or in a conventional plating basket. Alternatively, the plating solution may be sprayed, brushed or otherwise brought into contact with the surfaces to be plated. From the standpoint of control and maximum utilization of the plating solution, immersion is preferred.

Ultrasonic vibration of the object undergoing plating improves the uniformity and coherence of the gold plate. Any suitable means for supplying ultrasonic energy may be employed, for example when a clamp or holder is utilized to support the object being plated in the aqueous electroless plating solution, such holder may be suitably coupled to an ultrasonic transducer which is in turn connected to a source of high frequency A.-C. electrical potential. A frequency of about 20 kc. is eifective for the purpose of this invention.

It will be understood that a wide variety of specific forms of apparatus may be devised and employed in the performance of electroless plating as contemplated by the present invention.

The chemical constituency of the plating bath varies, of course, with the metal or combination of metals to be deposited. Stated generally, it comprises an alkaline aqueous solution of at least one complexing agent; at least one plating metal ion source of material, soluble in the solution and providing gold ions; and a reducing agent. In general the pH is in the range of from 7 to 12, and most usually in the range of from 8 to 11.

The solution is rendered alkaline by the use of a suitable base, preferably ammonium hydroxide. The operative range of concentration is about 15 to 40 grams per liter or, in any event, high enough to give a pH above 7 and preferably above 10. As the pH drops towards 7, the deposition rate falls off sharply. Satisfactory deposition rates are achieved throughout the operative range, but inasmuch as stability of the solution is inversely related to alkalinity, the pH in the higher portion of the range is preferred, eg a pH of above 10.

The complex-ing agent is a water soluble sulphi-te or meta-bisulphite of ammonium, or an alkali metal, e. g., sodium, potassium, or lithium. The permissible range of concentration of the complexing agent in the aqueous solution is from about 0.7 to 2.5 mols/liter. While variation in the concentration does not substantially affect the rate of deposition, the stability of the solution decreases with decreasing concentration. An optimum condition of stability at deposition rate is achieved in the range of from about 1.2 to 1.6 mols/liter (-200 Higher concentrations tend to cause the salts to crystallize out of solution. 1

The source of the plating metal ions of gold in the bath may be any compatible gold compounds which are soluble in the bath and provide gold ions in solution. For gold plating, the chloride, nitrate, acetate, sulphate, and various acidic and basic salts of gold, e.g., ammonium, chloraurate, aurichloric. acid, auribro mic acid, etc. A preferred water soluble compound productive of gold ions in the electroless plating baths of the present invention is aurichloric acid, HAuCl .3H O. In general, the permissible range of concentration of the gold ions in the aqueous solution is from about 0.013 to 0.05 mol per liter. At a higher concentration of gold, the gold complex formed in situ tends to become insoluble. At a concentration below about 0.013 mol per liter of gold, less satisfactory coverage of the substrate is found. At about 0.025 mol per liter, the maximum rate of 0.0001 inch per 30 minutes of film deposition was obtained. Experience has shown that, as a general rule, an excess of complexing agent is not detrimental to the process. The main requirement is that there is at least one donor group available to coordinate with each metal ion present. For most purposes, a nrol ratio of complexing agent to metal ion is conveniently in the range of from about 5:1 to about 25:1.

The reducing agent employed in the electroless plating solutions of the present invention is a very powerful reducing agent in comparison with the formaldehyde and polymeric formaldehyde reducing agents heretofor used in electroless plating compositions. It has been found that hydrazine, N H and hydroxylarnine, HONI-l and the alkyl derivatives of these materials in which the alkyl substituent contains from 1 to 3 carbon atoms, are particularly well adapted for use as reducing agents in the aqueous electroless plating baths of the present invention. Thus, methyl hydrazine, dimethyl hydrazine, ethyl hydrazine, diethyl hydrazine, propyl hydrazine, dipropyl hydrazine, acet'aldoxime, acetroxamine, propionaldoxime, and the like, are particularly useful in accordance herewith. The amount of the reducing agent which can be tolerated in the solution without introducing undesirable instability factors will be dependent upon the concentration of the other reactant materials in the bath. Generally, the reducing agent is present in an amount ranging from about 0.3 mol per liter to about 2.4 mols per liter. In the case of hydrazine, the material is operative over this range, but the optimum concentration of hydrazine is in the range of from about 1.2 to about 1.8 mols per liter of solution. About a concentration of 1.2 mols per liter, the plating rate utilizing hydrazine as the reducing agent was not effected, but the bath tends to become more unstable.

An increase in solution stability can be secured by incorporating in the compositions of the present invention from about 0.65 to about 1.95 mols per liter of a cycloaliphatic amine such as cyclohe-xylamine, methylcyclohexylamine, cyclopropylamine, cyclobutylaimine, cyclopentylamine, etc. While the cycloaliphatic aminesdo increase the solution stability, they tend to decrease the plating rate as the concentration of the stabilizing agent is increased. For example, in order to stabilize the solution at 85 C. for thirty minutes, 1.3 mols per liter of cyclohexylaimine is required. Additional cyclohexylamine dropped the plating rate from 0.000092 inch per 30 minutes to 0.000052 inch per 30 minutes. Solution stability per periods of from 25 minutes to 75 minutes or more, is regarded as satisfactory.

As indicated above, the pH range of the solutions of the present invention should be on the alkaline side, and broadly range from a pH of 7 to a pH of about 12. Ammonium hydroxide is a convenient alkalizing agent from adjusting the pH to the desired range although sodium hydroxide and potassium hydroxide may be used. An increase in the pH increases the plating rate considerably, but the bath tends to become more unstable as the temperature is increased. Thus, the higher the pH,

the lower the temperature which is to be used for carrying out the electroless plating opera-tion. Although an increase in temperature f avors bath decomposition, elevated temperatures are preferred for the autocatalytic reaction which occurs at the interface between the surface on which the deposition is taking place and the aqueous electroless plating bath.

As indicated above, agitation increases the rate of plating without substantially affecting the stability of the bath.

The substrate may, as above indicated, he metallic or non-metallic, such as a synthetic resinous film. In any event, best results are secured when the substrate whether metallic or non-metallic is previously sensitized by the deposition thereon of a very thin layer of a catalytic metal or discrete activating sites or nuclei, which may be, for example, nickel, cobalt, copper, silver, rhodium, gold, platinum, or palladium. These metal surfaces or catalytic nuclei may be deposited by any convenient means such as, electroplating, vaporization, or electroless plating, and provide a condition at the interface between the plating bath and the surface being plated which is receptive to and promotes the autocatalytic decomposition of the gold ions to metallic gold. The most preferred of these sensitizing materials is nickel, which has proved to be a very effective catalyst, even more so than gold.

It becomes convenient at this point to illustrate further the present invention by setting forth the preferred mode of carrying out the invention together with alternative modes, it being understood that these are merely illustrative of the invention and are not to be construed as limiting the invention to the precise scope thereof. Those skilled in the art following the direction and suggestions contained in the following examples will be able to proguce still further examples of gold electroless plating aths.

Examplel Mols per liter HAuCl -3H O 0.025 Sodium sulphite 1.6 Ammonium chloride 1.5 Cyclohexylamine 1.3 Hydrazine 1.8 Water, to make one liter.

The substrate used in this particular example was an electroless nickel plated steel sheet. The deposition of gold from the electroless gold plating bath was carried out at a temperature of C. with agitation and yielded a deposition rate of 0.00015 inch per hour. The solution of Example I is quite satisfactory for depositing 0.0001 inch to 0.002 inch of gold on a surface without continuous filtration. The solution life may be prolonged by employing continuous filtration of the plating bath during the course of the deposition. The foregoing bath of Example I represents the best compromise between rate of deposition of gold from the solution and bath stability under the conditions of plating. Solutions pursuant to the formulation of this example have stabilities in excess of one hour up to six hours.

Example II Mols per liter HAuCl -3H O 0.013 Sodium meta-bisulphite 1.0 Ammonium chloride 1.5 Cyclohexylamine 1.3 Hydrazine 1.8

Water, to make one liter.

The above solution is satisfactory for depositing 0.0001 inch to 0.0002 inch of gold on a nickel sensitized steel surface of 85 C. with mechanical agitation. Continuous filtration of the bath through a sintered glass filter improves the stability of the solution.

Example III 7. An electroless gold plating bath in accordance with Mols per liter claim 1 in which the reducing agent is hydrazine.

HAuBr -3H O 0.05 8. An electroless goldplating bath in accordance with Ammonium sulphite 1.3 claim 1 in which the reducing agent is hydr-oxylamine. Cyclohexylamine 1.5 5 9. An electroless gold plating bath in accordance with Hydroxylamine 2.0 claim 1 in which the stabilizing agent is cyclohexylamine. W t to make one liter. 10. An electroless gold plating bath in accordance with The above solution is satisfactory for deposition 0.0001 Claim 1 in which the Complexihg agent is Sodium sulphite inch to 0.0002 inch of gold on a silver sensitized Mylar the reducing agent is hydrazine, and the stabilizing agent plastic film at 85 C. with vigorous agitati-on by bubbling is cyclohfiXylaminei i h b h 11. An electroless gold plating bath in accordance with The following table illustrates further electroless gold claim 1 in which the complexing agent is sodium metaplating aqueous solution and examples of deposition rates bisulphite, the reducing agent is hydrazine and the stabilobtained. izing agent is cyclohexylamine.

TABLE Example Moles/liter, Gold Ion Source Decomposition N 0. Moles/liter, Agent Moles/liter, Reducing Agent Moles/liter, Stabilizer Rate, .001 in./

min. 85 C.

ifo-ms oinlu. re-uniso 1.8-Hydrazine 1.3-Cycl0hexylamine 0. 022 do .d0 0.026 (10 0.048

0.3-Hydrazine 0. 024 0.6-Hydrazine- 0. 034

1 .Z-Hydrazine 0. 047 QA-Hydrazine. 0. 048 1.8-Hydrazine. 0. 009 .-do 0.100

. 0. 112 Cyclohexylamine. 0. 110 .3-Cycl0hexylamine. 0. 092 .95-Cyclohexylaminc 0. 052

Lfi-dimethylhydrazine LS-phenylhydrazine Other ingredients which do not adversely aifect the plating of gold from the solution or the character of the film and its adhesion to the substrate may be included in the composition. Solution stability is also improved by continuous filtration of the plating bath during plating to remove suspended catalytic nuclei from the solution. Preferred practice involves cooling the bath as it leaves the plating tank, filtering, and reheating prior to circulation back to the plating tank.

Other modes of applying the principle of this invention may be employed instead of those specifically set forth above, changes being made as regards the details herein disclosed, provided the elements set forth in any of the following claims, or the equivalent of such be employed.

It is, therefore, particuluarly pointed out and distinctly claimed as the invention:

1. An electroless gold plating bath consisting essentially of an aqueous solution of a complexing agent selected from the group consisting of alkali metal sulphites, ammonium sulphite, alkali metal meta-bisulphites and ammonium meta-bisulphite, a water soluble source of gold ions, a reducing agent selected from the group consisting of hydrazine, alkyl hydrazines in which the alkyl group contains from 1 to 3 carbon atoms, hydroxylamine, and alkyl hydroxylamines in which the alkyl group contains from 1 to 3 carbon atoms, and a cycloaliphatic amine stabilizing agent.

2. An electroless gold plating bath in accordance with claim 1 having a pH of at least 8.

3. An electroless gold plating bath in accordance with claim 1 in which the complexing agent is an alkali metal sulphite.

4. An electroless gold plating bath in accordance with claim 3 in which the complexing agent is sodium sulphite.

5. An electroless gold plating bath in accordance with claim 1 in which the complexing agent is an alkali metal meta-bisulphite.

6. An electroless gold plating bath in accordance with claim 5 in which the complexing agent is sodium metabisulphite.

12. An electroless gold plating bath consisting essen tially of the following constituents in aqueous solution on a per liter basis:

Mols per liter Sodium sulphite 0.7-2.5 Hydrazine 0.3-2.4 Gold 0.013-005 Cyclohexylamine 0.65-1.95

13. An electroless gold plating bath consisting essentially of the following constituents in aqueous solution on a per liter basis:

Mols per liter HAuCl -3H O -2 0.025 Sodium sulphite 1. Ammonium chloride 1.5 Cyclohexylamine 1.3 Hydrazine 1.8

References Cited by the Examiner UNITED STATES PATENTS 2,976,181 3/ 1961 Brookshire. 3,032,436 5/ 1962 Gostin et al. 3,123,484 3/1964 Pokras et a1. 3,214,929 10/ 1965 Edson.

ALFRED L. LEAVITT, Primary Examiner.

R. S. KENDALL, Assistant Examiner.

Claims (2)

1. AN ELECTROLESS GOLD PLATING BATH CONSISTING ESSENTIALLY OF AN AQUEOUS SOLUTION OF A COMPLEXING AGENT SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL SULPHITES, AMMONIUM SULPHITE, ALKALI METAL META-BISULPHITES AND AMMONIUM META-BISULPHITE, A WATER SOLUBLE SOURCE OF GOLD IONS, A REDUCING AGENT SELECTED FROM THE GROUP CONSISTING OF HYDRAZINE, ALKYL HYDRAZINES IN WHICH THE ALKYL GROUP CONTAINS FROM 1 TO 3 CARBON ATOMS, HYDROXYLAMINE, AND ALKYL HYDROXYLAMINES IN WHICH THE ALKYL GROUP CONTAINS FROM 1 TO 3 CARBON ATOMS, AND A CYCLOALIPHATIC AMINE STABILIZING AGENT.
15. THE PROCESS OF AUTOCATALYTICALLY PLATING GOLD ON A NON-METALLIC SUBSTRATE WHICH COMPRISES SENSITIZING SAID SUBSTRATE BY DEPOSITING A FILM OF A METAL SELECTED FROM THE GROUP CONSISTING OF NICKEL, COBALT, COPPER, SILVER, RHODIUM, GOLD, PLATINUM, AND PALLADIUM ON SAID NONMETALLIC SUBSTRATE, AND THEREAFTER CONTACTING THE SENSITIZED NON-METAL SUBSTRATE WITH A SOLUTION ACCORDING TO CLAIM 1.
US3300328A 1963-11-12 1963-11-12 Electroless plating of gold Expired - Lifetime US3300328A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US3300328A US3300328A (en) 1963-11-12 1963-11-12 Electroless plating of gold

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US3300328A US3300328A (en) 1963-11-12 1963-11-12 Electroless plating of gold

Publications (1)

Publication Number Publication Date
US3300328A true US3300328A (en) 1967-01-24

Family

ID=23257837

Family Applications (1)

Application Number Title Priority Date Filing Date
US3300328A Expired - Lifetime US3300328A (en) 1963-11-12 1963-11-12 Electroless plating of gold

Country Status (1)

Country Link
US (1) US3300328A (en)

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3516848A (en) * 1965-10-18 1970-06-23 Sel Rex Corp Process and solution for sensitizing substrates for electroless plating
US3522074A (en) * 1965-06-28 1970-07-28 Minnesota Mining & Mfg Gold-plated high temperature sheet material
US3890455A (en) * 1972-06-23 1975-06-17 Ibm Method of electrolessly plating alloys
US4005229A (en) * 1975-06-23 1977-01-25 Ppg Industries, Inc. Novel method for the rapid deposition of gold films onto non-metallic substrates at ambient temperatures
US4082908A (en) * 1976-05-05 1978-04-04 Burr-Brown Research Corporation Gold plating process and product produced thereby
US4091128A (en) * 1976-10-08 1978-05-23 Ppg Industries, Inc. Electroless gold plating bath
US4091172A (en) * 1976-12-14 1978-05-23 Ppg Industries, Inc. Uniform gold films
FR2487858A1 (en) * 1980-08-04 1982-02-05 Schering Ag electroless gold plating bath of acid
EP0219788A1 (en) * 1985-10-14 1987-04-29 Hitachi, Ltd. Electroless gold plating solution
DE3614090C1 (en) * 1986-04-25 1987-04-30 Heraeus Gmbh W C Bath for the currentless deposition of gold layers
US4832743A (en) * 1986-12-19 1989-05-23 Lamerie, N.V. Gold plating solutions, creams and baths
US4971944A (en) * 1989-02-21 1990-11-20 Westinghouse Electric Corp. Method of electroless depositing of gold onto superconducting particles
EP0418715A2 (en) * 1989-09-18 1991-03-27 Hitachi, Ltd. Electroless gold plating solution and method for plating gold therewith
US5202151A (en) * 1985-10-14 1993-04-13 Hitachi, Ltd. Electroless gold plating solution, method of plating with gold by using the same, and electronic device plated with gold by using the same
US5803957A (en) * 1993-03-26 1998-09-08 C. Uyemura & Co.,Ltd. Electroless gold plating bath
US20060230979A1 (en) * 2003-06-05 2006-10-19 Akihiro Aiba Electroless gold plating solution
US20070056403A1 (en) * 2004-07-15 2007-03-15 Sony Corporation Electroconductive fine particle, method of producing electroconductive fine particle, and anisotropic electroconductive material
US20070209548A1 (en) * 2004-11-15 2007-09-13 Akihiro Aiba Electroless Gold Plating Solution

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2976181A (en) * 1957-12-17 1961-03-21 Hughes Aircraft Co Method of gold plating by chemical reduction
US3032436A (en) * 1960-11-18 1962-05-01 Metal Proc Co Inc Method and composition for plating by chemical reduction
US3123484A (en) * 1964-03-03 Ihzijm
US3214929A (en) * 1962-10-29 1965-11-02 Robert V Anderson Refrigeration unit having superheated gas feedback

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3123484A (en) * 1964-03-03 Ihzijm
US2976181A (en) * 1957-12-17 1961-03-21 Hughes Aircraft Co Method of gold plating by chemical reduction
US3032436A (en) * 1960-11-18 1962-05-01 Metal Proc Co Inc Method and composition for plating by chemical reduction
US3214929A (en) * 1962-10-29 1965-11-02 Robert V Anderson Refrigeration unit having superheated gas feedback

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3522074A (en) * 1965-06-28 1970-07-28 Minnesota Mining & Mfg Gold-plated high temperature sheet material
US3516848A (en) * 1965-10-18 1970-06-23 Sel Rex Corp Process and solution for sensitizing substrates for electroless plating
US3890455A (en) * 1972-06-23 1975-06-17 Ibm Method of electrolessly plating alloys
US4005229A (en) * 1975-06-23 1977-01-25 Ppg Industries, Inc. Novel method for the rapid deposition of gold films onto non-metallic substrates at ambient temperatures
US4082908A (en) * 1976-05-05 1978-04-04 Burr-Brown Research Corporation Gold plating process and product produced thereby
US4091128A (en) * 1976-10-08 1978-05-23 Ppg Industries, Inc. Electroless gold plating bath
US4091172A (en) * 1976-12-14 1978-05-23 Ppg Industries, Inc. Uniform gold films
FR2487858A1 (en) * 1980-08-04 1982-02-05 Schering Ag electroless gold plating bath of acid
DE3029785A1 (en) * 1980-08-04 1982-03-25 Schering Ag Acidic gold bath for the electroless deposition of gold
US4352690A (en) * 1980-08-04 1982-10-05 Schering Aktiengesellschaft Acid gold bath for the electroless deposition of gold
US5202151A (en) * 1985-10-14 1993-04-13 Hitachi, Ltd. Electroless gold plating solution, method of plating with gold by using the same, and electronic device plated with gold by using the same
EP0219788A1 (en) * 1985-10-14 1987-04-29 Hitachi, Ltd. Electroless gold plating solution
US4804559A (en) * 1985-10-14 1989-02-14 Hitachi, Ltd. Electroless gold plating solution
US4880464A (en) * 1985-10-14 1989-11-14 Hitachi, Ltd. Electroless gold plating solution
DE3614090C1 (en) * 1986-04-25 1987-04-30 Heraeus Gmbh W C Bath for the currentless deposition of gold layers
US4832743A (en) * 1986-12-19 1989-05-23 Lamerie, N.V. Gold plating solutions, creams and baths
US4971944A (en) * 1989-02-21 1990-11-20 Westinghouse Electric Corp. Method of electroless depositing of gold onto superconducting particles
EP0418715A2 (en) * 1989-09-18 1991-03-27 Hitachi, Ltd. Electroless gold plating solution and method for plating gold therewith
EP0418715A3 (en) * 1989-09-18 1991-07-31 Hitachi, Ltd. Electroless gold plating solution and method for plating gold therewith
US5198273A (en) * 1989-09-18 1993-03-30 Hitachi, Ltd. Electroless gold plating solution and method for plating gold therewith
US5803957A (en) * 1993-03-26 1998-09-08 C. Uyemura & Co.,Ltd. Electroless gold plating bath
US20060230979A1 (en) * 2003-06-05 2006-10-19 Akihiro Aiba Electroless gold plating solution
US7419536B2 (en) * 2003-06-05 2008-09-02 Nikko Materials Co., Ltd. Electroless gold plating liquid
CN100549228C (en) 2003-06-05 2009-10-14 日矿金属株式会社 Electroless gold plating solution
US20070056403A1 (en) * 2004-07-15 2007-03-15 Sony Corporation Electroconductive fine particle, method of producing electroconductive fine particle, and anisotropic electroconductive material
US20070209548A1 (en) * 2004-11-15 2007-09-13 Akihiro Aiba Electroless Gold Plating Solution
US7396394B2 (en) * 2004-11-15 2008-07-08 Nippon Mining & Metals Co., Ltd. Electroless gold plating solution

Similar Documents

Publication Publication Date Title
US3532518A (en) Colloidal metal activating solutions for use in chemically plating nonconductors,and process of preparing such solutions
US3632435A (en) Preparation of substrate for electroless deposition
US3370974A (en) Electroless plating on non-conductive materials
US3485597A (en) Electroless deposition of nickel-phosphorus based alloys
US3234031A (en) Reduction nickel plating with boron reducing agents and organic divalent sulfur stabilizers
US3403035A (en) Process for stabilizing autocatalytic metal plating solutions
US4002778A (en) Chemical plating process
US3873359A (en) Method of depositing a metal on a surface of a substrate
US5910340A (en) Electroless nickel plating solution and method
US5322553A (en) Electroless silver plating composition
US4039714A (en) Pretreatment of plastic materials for metal plating
US5250105A (en) Selective process for printing circuit board manufacturing
US4869970A (en) Radiation attenuation shielding
US6645557B2 (en) Metallization of non-conductive surfaces with silver catalyst and electroless metal compositions
US3690921A (en) Method for strongly adhering a metal film on ceramic substrates
US3937857A (en) Catalyst for electroless deposition of metals
US4006047A (en) Catalysts for electroless deposition of metals on comparatively low-temperature polyolefin and polyester substrates
US4322457A (en) Method of selectively depositing a metal on a surface
US3589916A (en) Autocatalytic gold plating solutions
US6331239B1 (en) Method of electroplating non-conductive plastic molded products
US6319308B1 (en) Coating compositions containing nickel and boron and particles
US4169171A (en) Bright electroless plating process and plated articles produced thereby
US2658839A (en) Process of chemical nickel plating
US3672938A (en) Novel precious metal sensitizing solutions
US4840820A (en) Electroless nickel plating of aluminum

Legal Events

Date Code Title Description
AS Assignment

Owner name: IMPERIAL CLEVITE INC., 2550 GOLF ROAD, ROLLING MEA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:GOULD INC., A CORP. OF DE;REEL/FRAME:003998/0236

Effective date: 19810928

Owner name: IMPERIAL CLEVITE INC., A CORP. OF PA,ILLINOIS

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:GOULD INC., A CORP. OF DE;REEL/FRAME:003998/0236

Effective date: 19810928