SELECTIVE NICKEL DEPOSITION
United States Patent 3658569
A process for selectively depositing nickel by irradiating selected portions of a substrate coated with an irradiation sensitive compound. Immersing the irradiated substrate in a developer deposits controlled amounts of nickel in the selected portions.
US Patent References:
/1207218.html
Roux - December 1916 - 1207218
Chemical nickel plating on nonmetallic materials
Gutzeit et al. - September 1954 - 2690403
Method of producing electronic semiconductor devices having a monocrystalline body with zones of respectively different conductance
Reuschel - October 1964 - 3152933
Method for growing single thin film crystals
Liebson - August 1967 - 3336159
METALLIZING PROCESS
Cescon - January 1970 - 3492151
/1207218.html
Roux - December 1916 - 1207218
Chemical nickel plating on nonmetallic materials
Gutzeit et al. - September 1954 - 2690403
Method of producing electronic semiconductor devices having a monocrystalline body with zones of respectively different conductance
Reuschel - October 1964 - 3152933
Method for growing single thin film crystals
Liebson - August 1967 - 3336159
METALLIZING PROCESS
Cescon - January 1970 - 3492151
Inventors:
Philipp, Warren H. (North Olmsted, OH)
Marsik, Stanley J. (Fairview Park, OH)
May, Charles E. (Rocky River, OH)
Marsik, Stanley J. (Fairview Park, OH)
May, Charles E. (Rocky River, OH)
Application Number:
04/876588
Publication Date:
04/25/1972
Filing Date:
11/13/1969
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
430/313, 250/424, 430/966
International Classes:
G03C1/725; G03C5/58; H05K3/10; G03C1/72; B41M5/00; C03C17/10
Field of Search:
117/47,93.3,138.8,13E,16R,1.7,62,152,124C 96/36.2 204/49,157.18AG 250/65F
US Patent References:
Primary Examiner:
Martin, William D.
Assistant Examiner:
Trenor, William R.
Claims:
What is claimed is
1. A method of forming permanent nickel prints in an improved photographic process comprising the steps of
2. A method as claimed in claim 1 wherein the substrate is ceramic.
3. A method as claimed in claim 1 wherein the substrate is porous paper.
4. A method as claimed in claim 1 wherein the substrate is glass.
5. A method as claimed in claim 1 wherein the irradiation is X-rays.
6. A method as claimed in claim 1 wherein the irradiation is ionizing particles.
7. A method as claimed in claim 1 wherein the nickel hypophosphite solution is an ammoniacal nickel-salt solution containing a hypophosphite ion.
8. A method as claimed in claim 1 wherein the developing solution is a solution of dilute aqueous ammonia.
9. A method as claimed in claim 1 including the step of masking predetermined portions of the substrate with a material that is opaque to radiation.
1. A method of forming permanent nickel prints in an improved photographic process comprising the steps of
2. A method as claimed in claim 1 wherein the substrate is ceramic.
3. A method as claimed in claim 1 wherein the substrate is porous paper.
4. A method as claimed in claim 1 wherein the substrate is glass.
5. A method as claimed in claim 1 wherein the irradiation is X-rays.
6. A method as claimed in claim 1 wherein the irradiation is ionizing particles.
7. A method as claimed in claim 1 wherein the nickel hypophosphite solution is an ammoniacal nickel-salt solution containing a hypophosphite ion.
8. A method as claimed in claim 1 wherein the developing solution is a solution of dilute aqueous ammonia.
9. A method as claimed in claim 1 including the step of masking predetermined portions of the substrate with a material that is opaque to radiation.
Description:
ORIGIN OF THE INVENTION
The invention described herein was made by employees of the United States Government and may be manufactured and used by or for the Government for governmental purposes without the payment of any royalties thereon or therefor.
BACKGROUND OF THE INVENTION
This invention is concerned with a radiation-chemical process for depositing nickel. The invention is particularly directed to an improved photographic process in which nickel is deposited in controlled amounts by the irradiation of nickel hypophosphite. The invention also relates to an improved process for making printed circuits.
Conventional photographic processes use silver halides. This material is expensive, and sometimes it may be in short supply. Silver halide treated paper is sensitive to ordinary light, and care must be taken in storing this photographic paper.
SUMMARY OF THE INVENTION
These problems have been solved by the present invention. A suitable substrate coated with nickel hypophosphite is irradiated to cause a chemical change. Nickel is deposited only on the irradiated areas by immersing the substrate in a developing solution. The density of the nickel deposit is a function of irradiation dose within a particular dose range.
OBJECTS OF THE INVENTION
It is, therefore, an object of the present invention to provide a method of depositing nickel throughout porous substrates.
Another object of the invention is to provide a process for the selective deposition of nickel on various substrates suitable for making printed circuits or the like.
A further object of the invention is to form permanent nickel images or prints with wide tonal gradations throughout the gray scale.
A still further object of the invention is to provide catalysts by depositing nickel in porous substrates, such as fritted glass, blotting paper and porous ceramics.
These and other objects and advantages of the invention will be apparent from the specification which follows.
DESCRIPTION OF THE PREFERRED EMBODIMENT
According to the present invention a suitable substrate, such as filter paper, blotting paper, or glass carries a nickel compound that is sensitive to irradiation. This substrate is first prepared by coating or impregnating with a solution containing nickel hypophosphite. The coated substrate is then dried.
The dry coated substrate is irradiated within a certain chosen range. This is preferably accomplished by subjecting the dry substrate to ionizing radiation, such as X-rays or electrons. A change occurs in the nickel hypophosphite as a result of this irradiation. This change is similar to that which occurs when silver halide photographic emulsions are exposed to light to form latent images. As a result, deposition of the nickel on the exposed areas is accomplished upon contact with a developing solution.
The developer is composed of ammoniacal nickel-salt solution containing a hypophosphite ion. However, if a catalytically active nickel is desired, the developer is simply dilute aqueous ammonia.
The nickel deposits only in the areas exposed to radiation. By using a suitable mask that is opaque to radiation, selective deposition of nickel on a substrate can be accomplished to provide printed circuits.
Test samples were prepared to better illustrate the invention. In the first sample, filter paper of medium porosity was dipped in a solution having the following composition:
Nickel hypophosphite Ni(H 2 PO 2 ) 2 . 6H 2 O 10 grams Concentrated aqueous ammonia (28 to 30% NH 3 ) 18 ml. Mucilage 10 ml.
The treated paper was masked with variable thicknesses of ordinary paper. The masked paper was irradiated with 65 KV X-rays for a predetermined time to avoid overexposure.
Subsequent to exposure the paper was developed in an aqueous solution containing:
Nickel (II) Sulfate or Nickel (II) Chloride 0.1 molar Sodium Hypophosphite NaH 2 PO 2 0.2 molar Ammonia 1.0 molar
The development of an image was complete in less than 1 minute. After development the paper containing the nickel image was washed in water to remove excess developer. The image exhibited tonal gradations according to the thickness of the mask.
The treated filter paper was given a short exposure of less than 30 seconds to 1 MeV electrons at a beam density of about 0.5 microamp per square centimeter. This produced an image similar to that produced by the 65 KV X-rays.
In another sample the filter paper treated as described in the first sample was masked with a fine wire screen and exposed to 65 KV X-rays. Upon development a sharp, finely detailed image formed in the exposed areas.
A pattern was made by removing lead oxide from a lead oxide coated filter paper. The resulting pattern was used as a mask. Using the same procedure as in the previous samples a sharp black nickel image of the scratched pattern was obtained.
A smooth glass plate was coated by brushing on the nickel hypophosphite solution prepared in the first example. The coated plate was permitted to dry at room temperature. The dry coated plate was exposed to 65 KV X-rays and developed as in Example 1. A strong adherent nickel mirror formed on the glass plate. This mirror had the ability of being polished on the coated side. Similar results were obtained using 1 MeV electrons as a radiation source.
Catalytically active nickel distributed throughout a thick blotting paper was obtained by immersing the blotting paper in the following solution:
Nickel hypophosphite Ni(H 2 PO 2 ) 2 . 6H 2 O 10 grams Concentrated aqueous ammonia (28 to 30% NH 3 ) 25 ml.
The blotting paper was allowed to dry at room temperature. The dry treated specimen was irradiated with 1 MeV electrons for about 30 minutes with a current density of about 0.5 microamp per square centimeter. The irradiated paper was then developed in dilute aqueous ammonia which caused the deposition of the nickel by decomposition of the irradiated nickel hypophosphite already present in the substrate. The blotting paper containing the active nickel showed good catalytic properties in promoting the Cannizzaro reaction and in the decomposition of alkaline sodium hypophosphite solutions. A typical analysis of the nickel impregnated blotting paper prepared by this method showed it contained 56 percent nickel by weight.
The invention described herein was made by employees of the United States Government and may be manufactured and used by or for the Government for governmental purposes without the payment of any royalties thereon or therefor.
BACKGROUND OF THE INVENTION
This invention is concerned with a radiation-chemical process for depositing nickel. The invention is particularly directed to an improved photographic process in which nickel is deposited in controlled amounts by the irradiation of nickel hypophosphite. The invention also relates to an improved process for making printed circuits.
Conventional photographic processes use silver halides. This material is expensive, and sometimes it may be in short supply. Silver halide treated paper is sensitive to ordinary light, and care must be taken in storing this photographic paper.
SUMMARY OF THE INVENTION
These problems have been solved by the present invention. A suitable substrate coated with nickel hypophosphite is irradiated to cause a chemical change. Nickel is deposited only on the irradiated areas by immersing the substrate in a developing solution. The density of the nickel deposit is a function of irradiation dose within a particular dose range.
OBJECTS OF THE INVENTION
It is, therefore, an object of the present invention to provide a method of depositing nickel throughout porous substrates.
Another object of the invention is to provide a process for the selective deposition of nickel on various substrates suitable for making printed circuits or the like.
A further object of the invention is to form permanent nickel images or prints with wide tonal gradations throughout the gray scale.
A still further object of the invention is to provide catalysts by depositing nickel in porous substrates, such as fritted glass, blotting paper and porous ceramics.
These and other objects and advantages of the invention will be apparent from the specification which follows.
DESCRIPTION OF THE PREFERRED EMBODIMENT
According to the present invention a suitable substrate, such as filter paper, blotting paper, or glass carries a nickel compound that is sensitive to irradiation. This substrate is first prepared by coating or impregnating with a solution containing nickel hypophosphite. The coated substrate is then dried.
The dry coated substrate is irradiated within a certain chosen range. This is preferably accomplished by subjecting the dry substrate to ionizing radiation, such as X-rays or electrons. A change occurs in the nickel hypophosphite as a result of this irradiation. This change is similar to that which occurs when silver halide photographic emulsions are exposed to light to form latent images. As a result, deposition of the nickel on the exposed areas is accomplished upon contact with a developing solution.
The developer is composed of ammoniacal nickel-salt solution containing a hypophosphite ion. However, if a catalytically active nickel is desired, the developer is simply dilute aqueous ammonia.
The nickel deposits only in the areas exposed to radiation. By using a suitable mask that is opaque to radiation, selective deposition of nickel on a substrate can be accomplished to provide printed circuits.
Test samples were prepared to better illustrate the invention. In the first sample, filter paper of medium porosity was dipped in a solution having the following composition:
Nickel hypophosphite Ni(H 2 PO 2 ) 2 . 6H 2 O 10 grams Concentrated aqueous ammonia (28 to 30% NH 3 ) 18 ml. Mucilage 10 ml.
The treated paper was masked with variable thicknesses of ordinary paper. The masked paper was irradiated with 65 KV X-rays for a predetermined time to avoid overexposure.
Subsequent to exposure the paper was developed in an aqueous solution containing:
Nickel (II) Sulfate or Nickel (II) Chloride 0.1 molar Sodium Hypophosphite NaH 2 PO 2 0.2 molar Ammonia 1.0 molar
The development of an image was complete in less than 1 minute. After development the paper containing the nickel image was washed in water to remove excess developer. The image exhibited tonal gradations according to the thickness of the mask.
The treated filter paper was given a short exposure of less than 30 seconds to 1 MeV electrons at a beam density of about 0.5 microamp per square centimeter. This produced an image similar to that produced by the 65 KV X-rays.
In another sample the filter paper treated as described in the first sample was masked with a fine wire screen and exposed to 65 KV X-rays. Upon development a sharp, finely detailed image formed in the exposed areas.
A pattern was made by removing lead oxide from a lead oxide coated filter paper. The resulting pattern was used as a mask. Using the same procedure as in the previous samples a sharp black nickel image of the scratched pattern was obtained.
A smooth glass plate was coated by brushing on the nickel hypophosphite solution prepared in the first example. The coated plate was permitted to dry at room temperature. The dry coated plate was exposed to 65 KV X-rays and developed as in Example 1. A strong adherent nickel mirror formed on the glass plate. This mirror had the ability of being polished on the coated side. Similar results were obtained using 1 MeV electrons as a radiation source.
Catalytically active nickel distributed throughout a thick blotting paper was obtained by immersing the blotting paper in the following solution:
Nickel hypophosphite Ni(H 2 PO 2 ) 2 . 6H 2 O 10 grams Concentrated aqueous ammonia (28 to 30% NH 3 ) 25 ml.
The blotting paper was allowed to dry at room temperature. The dry treated specimen was irradiated with 1 MeV electrons for about 30 minutes with a current density of about 0.5 microamp per square centimeter. The irradiated paper was then developed in dilute aqueous ammonia which caused the deposition of the nickel by decomposition of the irradiated nickel hypophosphite already present in the substrate. The blotting paper containing the active nickel showed good catalytic properties in promoting the Cannizzaro reaction and in the decomposition of alkaline sodium hypophosphite solutions. A typical analysis of the nickel impregnated blotting paper prepared by this method showed it contained 56 percent nickel by weight.