US2152809A - Method of producing finely divided metallic layers - Google Patents
Method of producing finely divided metallic layers Download PDFInfo
- Publication number
- US2152809A US2152809A US55633A US5563335A US2152809A US 2152809 A US2152809 A US 2152809A US 55633 A US55633 A US 55633A US 5563335 A US5563335 A US 5563335A US 2152809 A US2152809 A US 2152809A
- Authority
- US
- United States
- Prior art keywords
- layer
- silver
- finely divided
- metallic layers
- heating
- 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
Links
- 238000000034 method Methods 0.000 title description 16
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 18
- 229910052709 silver Inorganic materials 0.000 description 18
- 239000004332 silver Substances 0.000 description 18
- 238000000576 coating method Methods 0.000 description 12
- 238000010438 heat treatment Methods 0.000 description 12
- 239000011248 coating agent Substances 0.000 description 11
- 239000010445 mica Substances 0.000 description 10
- 229910052618 mica group Inorganic materials 0.000 description 10
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 5
- 239000007789 gas Substances 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 239000001301 oxygen Substances 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- 239000002245 particle Substances 0.000 description 5
- 238000009834 vaporization Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 3
- 238000009413 insulation Methods 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 230000008016 vaporization Effects 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000005469 granulation Methods 0.000 description 2
- 230000003179 granulation Effects 0.000 description 2
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 2
- 229910052753 mercury Inorganic materials 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- NDVLTYZPCACLMA-UHFFFAOYSA-N silver oxide Chemical compound [O-2].[Ag+].[Ag+] NDVLTYZPCACLMA-UHFFFAOYSA-N 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 241000699670 Mus sp. Species 0.000 description 1
- 206010070834 Sensitisation Diseases 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000004519 grease Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 208000017983 photosensitivity disease Diseases 0.000 description 1
- 231100000434 photosensitization Toxicity 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
- 230000008313 sensitization Effects 0.000 description 1
- 229910001923 silver oxide Inorganic materials 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
- H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
- H01J29/10—Screens on or from which an image or pattern is formed, picked up, converted or stored
- H01J29/36—Photoelectric screens; Charge-storage screens
- H01J29/39—Charge-storage screens
- H01J29/43—Charge-storage screens using photo-emissive mosaic, e.g. for orthicon, for iconoscope
Definitions
- the mosaic screen represents a surface collection of elementary photo-cells, which produce electrical charges corresponding with the particular exposure. Further be employed for controlling the transmitter in suitable fashion, by transmitting capacita tively these charges to the silvered rear side con- This appllcanected with an amplifier device.
- the production of the layer consisting of finest particles of metal is accompanied by considerable difliculties, both as regards selection of the material for the intermediate insulating layer as well as the method of insulation.
- intermediate dielectriclayerssheets of mica or other suitable bases forexai'nple, ceramic materiaLcertaln kinds of glass, etc., the surface of this base preferably being made smooth by pole ishing.
- this base there is produced in suitpowers of adhesion, to produce a metallic layer in able fashion a metallic coating, for example a silver, copper or the like coating.
- a metallic coating of this nature may be produced, for example, chemically, by cathode atomization or by thermal application in vapour form.
- the metallized plates are then heated to high temperature in an atmosphere of indifferent gas or in vacuum.
- the temperatures require to These chargesmay then In Germany be very high, for example in the case of silver to about 1000, in order to obtain a brief fusing of the layer of silver, whereby the surface is then converted from the previously unitary structureless metallic surface into avery even mosaic con- 5 sisting of small drops of metal of negligible diameter and insulated against each other.
- this heating is performed extremely rapidly, preferably by means of eddy current heating in high-frequency furnaces. 10.
- the metallic coating is acted upon not directly, but indirectly by radiation from a heating plate.
- the metallic coating is acted upon not directly, but indirectly by radiation from a heating plate.
- the surface of the base is preferably made smooth by polishing, in order 20 to accelerate the insular formation during the" heating process.
- mice. is alternately oxidized and reduced. This method is performed in the most convenient fornrby glow' discharge in an atmosphere of al- 35 ternately introduced oxygen and hydrogen at. sutiable pressure (approximately 1 mm. mercury).
- the alternate oxidation and reduction might also be replacedto a certain extent by a suitable temperature treatment.
- the silvered plate is heated in oxygen at first up to the temperature forformation of silver oxide, and then additionally heated in vacuum until the silver, oxide has become dissociated. The temperature is thereupon again low- 45 ered, etc.
- the silver layer to be granulated is in the most convenient form placed opposite to a plate connected up as anode, withthe intermediate, connection of' a grid-like electrode connected up 50 as cathode.
- the layer of silver does not possess any electrically conductive connection with the cathode.
- the layer of silver might also be connected up. as cathode.
- FIG. 1 shows diagrammatically by way of example the arrangement for carrying out the method according to the invention.
- FIG. 1 shows the indirect heating by means of a heating plate I, which heats by radiation the layer of silver [mounted on the supporting ma- Since this heating required to commence instantaneously, the heating is preferably performed by eddy currents,
- Fig. 2 shows the arrangement for carrying out the glow discharge process.
- an electrode 5 which is connected up as anode and is situated opposite to a grid-like cath- .ode i.
- the metallic layer 1 to be granulated is arranged within reach of the glow discharge which develops in the case of a suitable filling of gas. 1 is the metallic layer on the base 8.
- Figs. 3 and 4 there is illustrated by way of example the finished product.
- the intermediate dielectric layer which acts as base for the coatings l and H.
- the coating Ill represents the thin layer of metal divided upon into finest elementary particles, whilst II is intended as capacitative counter-coating for the photo- ⁇ cell arrangement.
- a well-cleaned mica plate with all grease re;- moved is coated by the thermal vaporization of silver with a silver layer of approximately 95 44 in thickness.
- a thickness of the layer approximately midway of the stated range, i. e., approximately th to 95 produced the best results.
- the application of the layer by vaporization is performed in a suitable vessel from which the air has been removed, the distance between the mica plate to be treated and the evaporation furnace being of such extent that a very even coating is obtained. Insulation edges of a desired kind may be allowed to remain by selective screening.
- a certain amount of air or oxygen is allowed to enter the vessel, and the part of the vessel in which the plate is situated, is heated to approximately 400-450 C. This latter operation extends over a period of approximately 15 to "30 minutes.
- the initial layer is made thinner, a granulation ofany kind is not to be determined with the usual optical means available. If the layer is too thick, there is certainly a granulation up to a certain point, but the particles are situated so close together that the requisite insulation maybe not obtained. If on the other hand the layer is still thicker (completely opaque), a distribution according to the described process may not be accomplished at all.
- Mica plates of this kind which are furnished with a silver screen in the manner stated, may then be employed in the known fashion, by silvering the rear side and by oxidation and sensitization of the front screen surface, as light-sensitive mosaic electrodes in television transmission tubes, for instance, tubes known under, the name of Iconoscope.
Landscapes
- Inorganic Insulating Materials (AREA)
- Silicates, Zeolites, And Molecular Sieves (AREA)
- Physical Vapour Deposition (AREA)
- Surface Treatment Of Glass (AREA)
Description
April'4, 1939 N 2,152,809
METHOD OF PRODUCING FINELY DIVIDED METALLIC LAYERS ori inalnifed May 28, 1935 waw.
Patented Apr. 4, 1939 UNITED STATES.
.PATENTX' OFFICE METH D OF rnonucma many DIVIDED METALLIC Lamas I Gerhard Liebmann, Berlin, Germany Original application May 28, 1935, Serial No. 23,845. Divided and this application December 21, 1935, Serial No. 55,633.
May 31, 1934 2 Claims.
ployed more particularly in certain television image recording methods, After corresponding treatment the mosaic screen represents a surface collection of elementary photo-cells, which produce electrical charges corresponding with the particular exposure. further be employed for controlling the transmitter in suitable fashion, by transmitting capacita tively these charges to the silvered rear side con- This appllcanected with an amplifier device.
tion is a division of application Serial Number 23,845 filed May 28, 1935, and now Patent Numiber 2,131,187.
The production of the layer consisting of finest particles of metal is accompanied by considerable difliculties, both as regards selection of the material for the intermediate insulating layer as well as the method of insulation.
- It is possible to employ micafor the intermediate insulating layer. The use of this material when employing a heating process for dividing a metallic layer into single elementary parts is confronted by difliculties owing to the inconstancy of the temperatureand the nature of the surface. When employing a method for producing the distribution by means of engraving machines or in the case of chemical treatment it is impossible in numerous cases, owing to the small 40 corresponding distribution.
According to the invention, there are employed as intermediate dielectriclayerssheets of mica or other suitable bases, forexai'nple, ceramic materiaLcertaln kinds of glass, etc., the surface of this base preferably being made smooth by pole ishing. On this base there is produced in suitpowers of adhesion, to produce a metallic layer in able fashion a metallic coating, for example a silver, copper or the like coating. A metallic coating of this nature may be produced, for example, chemically, by cathode atomization or by thermal application in vapour form. The metallized plates are then heated to high temperature in an atmosphere of indifferent gas or in vacuum. If the metallic coating is of certain thickness (no longer transparent) the temperatures require to These chargesmay then In Germany be very high, for example in the case of silver to about 1000, in order to obtain a brief fusing of the layer of silver, whereby the surface is then converted from the previously unitary structureless metallic surface into avery even mosaic con- 5 sisting of small drops of metal of negligible diameter and insulated against each other. According to the invention, this heating is performed extremely rapidly, preferably by means of eddy current heating in high-frequency furnaces. 10.
In this connection the metallic coating is acted upon not directly, but indirectly by radiation from a heating plate. In the case of very thin metallic layers it is possible to manage with considerably lower temperatures, which in view of VII the low temperature constancy of mica is of ad-. vantage when employing a material of this kind. When using other materials, such as ceramic substances, glass or the like, the surface of the base is preferably made smooth by polishing, in order 20 to accelerate the insular formation during the" heating process.
According to the invention, it is also possible to deposit the metallic layer on a heated base,
so that small globules are likewise formed right 25" from the commencement. When using mica, however, the method of subsequently heating the deposited metal as described in the above is to be preferred.
Anadditional method for insular formation so resides according to the invention in the fact that a thin layer of silver deposited, for example,
on mice. is alternately oxidized and reduced. This method is performed in the most convenient fornrby glow' discharge in an atmosphere of al- 35 ternately introduced oxygen and hydrogen at. sutiable pressure (approximately 1 mm. mercury). The alternate oxidation and reduction might also be replacedto a certain extent by a suitable temperature treatment. In this con- 40 nection the silvered plate is heated in oxygen at first up to the temperature forformation of silver oxide, and then additionally heated in vacuum until the silver, oxide has become dissociated. The temperature is thereupon again low- 45 ered, etc. In the case of 'the glow discharge method the silver layer to be granulated is in the most convenient form placed opposite to a plate connected up as anode, withthe intermediate, connection of' a grid-like electrode connected up 50 as cathode. In this respect the layer of silver does not possess any electrically conductive connection with the cathode. The layer of silver might also be connected up. as cathode. In this,
however, there has been found to exist the dis- 5 Y terial 3, for example mica.
advantage that the oxidizing and reducing process takcs'place more strongly in the vicinity of the connectionbetween the lead and the layer than at other points. Asfinal stage of the process, after production of the discrete particles ofsilver, there is conveniently performed, a light oxidation. as in this manner it is possible to obtain a layer which is advantageously suited for photo sensitization.
In the drawing there is shown diagrammatically by way of example the arrangement for carrying out the method according to the invention. In the drawing- Fig.1 shows the indirect heating by means of a heating plate I, which heats by radiation the layer of silver [mounted on the supporting ma- Since this heating required to commence instantaneously, the heating is preferably performed by eddy currents,
which is represented diagrammatically by the high-frequency coil 4. Fig. 2 shows the arrangement for carrying out the glow discharge process. In the same there is provided an electrode 5, which is connected up as anode and is situated opposite to a grid-like cath- .ode i. The metallic layer 1 to be granulated is arranged within reach of the glow discharge which develops in the case of a suitable filling of gas. 1 is the metallic layer on the base 8. In
Figs. 3 and 4 there is illustrated by way of example the finished product. In these 9 is the intermediate dielectric layer, which acts as base for the coatings l and H. The coating Ill represents the thin layer of metal divided upon into finest elementary particles, whilst II is intended as capacitative counter-coating for the photo-{ cell arrangement.
The experiments according to the invention have proved especially useful the following special embodiment of the present invention.
A well-cleaned mica plate with all grease re;- moved is coated by the thermal vaporization of silver with a silver layer of approximately 95 44 in thickness. A thickness of the layer approximately midway of the stated range, i. e., approximately th to 95 produced the best results. The application of the layer by vaporization is performed in a suitable vessel from which the air has been removed, the distance between the mica plate to be treated and the evaporation furnace being of such extent that a very even coating is obtained. Insulation edges of a desired kind may be allowed to remain by selective screening. After the application of the silver layer by vaporization has been completed a certain amount of air or oxygen is allowed to enter the vessel, and the part of the vessel in which the plate is situated, is heated to approximately 400-450 C. This latter operation extends over a period of approximately 15 to "30 minutes.
becoming entirely useless.
After cooling it will be noticed that the coating on the plate has been divided into single well-sepa rated crystals of about 1;!- in size. 1
It has been found that to obtain this effect it is necessary 1. To adhere to the above stated range as regards the thickness of the layer, and
2. To employ a suitable gas atmosphere.
If the initial layeris made thinner, a granulation ofany kind is not to be determined with the usual optical means available. If the layer is too thick, there is certainly a granulation up to a certain point, but the particles are situated so close together that the requisite insulation maybe not obtained. If on the other hand the layer is still thicker (completely opaque), a distribution according to the described process may not be accomplished at all.
In this case temperatures would require to be employed which come very near to the fusing point of'the silver (800 to l,000 C.), and considerable difliculties are-then encountered-in preventing the mica from The size of the formed particles is also a wholly different one in the last mentionedcase. Further, it has been found that even with suitable layers a separation does not take place when the process is performed in an extremely high vacuum (higher than mm. Hg). The presence of a certain gas atmosphere (presumably oxygen) is accordingly necessary for the separation at the low temperature stated.
Mica plates of this kind, which are furnished with a silver screen in the manner stated, may then be employed in the known fashion, by silvering the rear side and by oxidation and sensitization of the front screen surface, as light-sensitive mosaic electrodes in television transmission tubes, for instance, tubes known under, the name of Iconoscope.
I claim: 7 9
1. In the process of manufacturing a photoelectric mosaic screen for television transmission tubes, the steps of coating a thin mica plate by thermal vaporisation of silver in vacuum with a transparent silver layer of approximately -.5
micron in thickness, and of granulating this layer into fine areas by heating the plate in a rarifled atmosphere containing oxygen to a temperature below 500 C.
2. In the process of manufacturing a photoelectric mosaic screen for television transmission tubes, the steps of coating a thin mica plate by thermal vaporisation of silver in vacuum with a transparent silver layer of approximately -.5 micron in thickness, and of granulating this layer into ilneareas by heating the plate in a gas atmosphere of about 1 mm. mercury pressure during to 30 minutes to a temperature below 500 C.
GERHARD LIEBMANN.
Priority Applications (9)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL48515D NL48515C (en) | 1934-05-25 | ||
| NL58595D NL58595C (en) | 1934-05-25 | ||
| BE409651D BE409651A (en) | 1934-05-25 | ||
| DER90663D DE725735C (en) | 1934-05-25 | 1934-05-25 | Process for the production of finely divided metal layers for mosaic raster photocells for charge storage |
| DER104168D DE740343C (en) | 1934-05-25 | 1934-06-02 | Process for the production of finely divided metal layers |
| FR790617D FR790617A (en) | 1934-05-25 | 1935-05-28 | Manufacturing process of very fine subdivision metal layers |
| US23845A US2131187A (en) | 1934-05-25 | 1935-05-28 | Method of producing finely divided metallic layers |
| GB15710/35A GB459231A (en) | 1934-05-25 | 1935-05-30 | Method of producing finely divided metallic layers |
| US55633A US2152809A (en) | 1934-05-25 | 1935-12-21 | Method of producing finely divided metallic layers |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DER90663D DE725735C (en) | 1934-05-25 | 1934-05-25 | Process for the production of finely divided metal layers for mosaic raster photocells for charge storage |
| DE459231X | 1934-06-01 | ||
| US23845A US2131187A (en) | 1934-05-25 | 1935-05-28 | Method of producing finely divided metallic layers |
| US55633A US2152809A (en) | 1934-05-25 | 1935-12-21 | Method of producing finely divided metallic layers |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2152809A true US2152809A (en) | 1939-04-04 |
Family
ID=32074464
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US55633A Expired - Lifetime US2152809A (en) | 1934-05-25 | 1935-12-21 | Method of producing finely divided metallic layers |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US2152809A (en) |
| BE (1) | BE409651A (en) |
| DE (1) | DE725735C (en) |
| FR (1) | FR790617A (en) |
| GB (1) | GB459231A (en) |
| NL (2) | NL58595C (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2681886A (en) * | 1948-12-29 | 1954-06-22 | Bell Telephone Labor Inc | Preparation of two-sided mosaic screen |
| US2765419A (en) * | 1951-11-03 | 1956-10-02 | Gen Electric | Electroluminescent cell |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2429088A (en) * | 1942-07-14 | 1947-10-14 | Johnson Matthey Co Ltd | Production of electrical condenser plates |
| DE849570C (en) * | 1949-04-22 | 1952-09-15 | Fernseh Gmbh | Process for the production of very fine-meshed net films |
-
0
- BE BE409651D patent/BE409651A/xx unknown
- NL NL48515D patent/NL48515C/xx active
- NL NL58595D patent/NL58595C/xx active
-
1934
- 1934-05-25 DE DER90663D patent/DE725735C/en not_active Expired
-
1935
- 1935-05-28 FR FR790617D patent/FR790617A/en not_active Expired
- 1935-05-30 GB GB15710/35A patent/GB459231A/en not_active Expired
- 1935-12-21 US US55633A patent/US2152809A/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2681886A (en) * | 1948-12-29 | 1954-06-22 | Bell Telephone Labor Inc | Preparation of two-sided mosaic screen |
| US2765419A (en) * | 1951-11-03 | 1956-10-02 | Gen Electric | Electroluminescent cell |
Also Published As
| Publication number | Publication date |
|---|---|
| FR790617A (en) | 1935-11-25 |
| NL58595C (en) | |
| NL48515C (en) | |
| DE725735C (en) | 1942-10-10 |
| BE409651A (en) | |
| GB459231A (en) | 1936-12-30 |
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