US2702270A - Method of making fine mesh metallic screens - Google Patents
Method of making fine mesh metallic screens Download PDFInfo
- Publication number
- US2702270A US2702270A US292354A US29235452A US2702270A US 2702270 A US2702270 A US 2702270A US 292354 A US292354 A US 292354A US 29235452 A US29235452 A US 29235452A US 2702270 A US2702270 A US 2702270A
- Authority
- US
- United States
- Prior art keywords
- wax
- metal
- grooves
- plate
- screens
- 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
- 238000004519 manufacturing process Methods 0.000 title claims description 16
- 229910052751 metal Inorganic materials 0.000 claims description 49
- 239000002184 metal Substances 0.000 claims description 49
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 28
- 229910052763 palladium Inorganic materials 0.000 claims description 14
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 12
- 238000004544 sputter deposition Methods 0.000 claims description 11
- 239000002904 solvent Substances 0.000 claims description 8
- 229910052697 platinum Inorganic materials 0.000 claims description 6
- 239000000919 ceramic Substances 0.000 claims description 5
- 238000004070 electrodeposition Methods 0.000 claims description 5
- 239000010408 film Substances 0.000 claims description 5
- 239000007787 solid Substances 0.000 claims description 5
- 239000010409 thin film Substances 0.000 claims description 4
- 238000001704 evaporation Methods 0.000 claims description 3
- 239000001993 wax Substances 0.000 description 33
- 238000000034 method Methods 0.000 description 29
- 239000011248 coating agent Substances 0.000 description 22
- 238000000576 coating method Methods 0.000 description 22
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 16
- 239000011521 glass Substances 0.000 description 9
- 229910052759 nickel Inorganic materials 0.000 description 8
- 239000000243 solution Substances 0.000 description 7
- 230000005540 biological transmission Effects 0.000 description 6
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 6
- 229910052737 gold Inorganic materials 0.000 description 6
- 239000010931 gold Substances 0.000 description 6
- 235000013871 bee wax Nutrition 0.000 description 5
- 239000012166 beeswax Substances 0.000 description 5
- 238000000151 deposition Methods 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 238000007747 plating Methods 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 4
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- 239000012153 distilled water Substances 0.000 description 3
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 239000000725 suspension Substances 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 229910052797 bismuth Inorganic materials 0.000 description 2
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 230000035699 permeability Effects 0.000 description 2
- 239000003208 petroleum Substances 0.000 description 2
- 235000011149 sulphuric acid Nutrition 0.000 description 2
- 239000001117 sulphuric acid Substances 0.000 description 2
- 235000010919 Copernicia prunifera Nutrition 0.000 description 1
- 244000180278 Copernicia prunifera Species 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 1
- 239000004327 boric acid Substances 0.000 description 1
- 230000001680 brushing effect Effects 0.000 description 1
- 230000001427 coherent effect Effects 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 229910000365 copper sulfate Inorganic materials 0.000 description 1
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000009713 electroplating Methods 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- LGQLOGILCSXPEA-UHFFFAOYSA-L nickel sulfate Chemical compound [Ni+2].[O-]S([O-])(=O)=O LGQLOGILCSXPEA-UHFFFAOYSA-L 0.000 description 1
- 229910000363 nickel(II) sulfate Inorganic materials 0.000 description 1
- 239000012188 paraffin wax Substances 0.000 description 1
- 239000012047 saturated solution Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
- H01J9/02—Manufacture of electrodes or electrode systems
- H01J9/14—Manufacture of electrodes or electrode systems of non-emitting electrodes
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D1/00—Electroforming
- C25D1/08—Perforated or foraminous objects, e.g. sieves
Definitions
- screens made by the method of the present invention can be used for any desired purpose, one of the applications for which they are particularly designed is that of an electrodein television camera tubes. Screens used in television camera tubes are required to be extremely uniform, be of very fine mesh, capable of being stretched taut without curling, and also be of relattvely high electron permeability and light permeability.
- metal screens of fine mesh have been made by a number of difierent methods.
- One of these methods was to make the screen of woven wire of extreme thinness. This method has proven generally unsatisfactory because of the difiiculty of carrying it out and because of the non-uniformity of the product made. Such screens also have relatively low light transmission and electron transmission values.
- Another method formerly used has involved the electro-deposition of metal upon conductive parts of a pattern made with the aid of a light sensitive emulsion. In general, screens made by this method have proven unsatisfactory for about the same reasons as woven wire screens.
- the present invention is an improvement in the method described in the above-mentioned patent. It is much easier to use in factory production and produces screens of greater uniformity and more satisfactory texture.
- the improved method of the present invention comprises the steps of depositing a very thin coating of wax over the entire surface of a hard ceramic master plate which has previously been provided with a grid work of etched grooves having a spacing such as required in the finished screen, depositing a thin layer of a metal such as palladium, platinum, or gold on top of the wax coating by a sputtering process, removing all of the sputtered metal coating from the raised areas between the etched. grooves, electro-depositing another metal over the sputtered metal coating in the grooves so as to form a grid work or screen of metal, and separating the formed screen from the coated ceramic master plate.
- One object of the present invention is to provide an improved method of making fine mesh metallic screens.
- Another object of the present invention is to provide a method of making fine mesh screens which are less susceptible to curling and tearing.
- Another object of the invention is to provide an improved method of making very fine mesh metallic screens 2,702,270 Patented Feb. 15, 1955 in which the product is more uniform than in previously used processes.
- Another object of the present invention is to provide an improved method of making fine mesh screens which is more practical in ordinary factory production.
- Another object of the present invention is to provide an improved method of making fine mesh screens which enables the elimination of certain factors which, in the past, have proven very difiicult to control.
- Another object of the invention is to provide an improved method of making fine mesh screens which enables the re-use of glass masters formerly discarded because of slight surface imperfections.
- Figure 1 1s a perspective view of a glass master plate or matrix having on one surface a grid work of fine grooves corresponding in number and width to the metal screen which is to be the final product,
- Figure 2 is a magnified fragmentary view of part of the screen portion of the master plate of Figure 1,
- Figure 3 is a view like that of Figure 2, the portion of the plate shown being coated with a thin film of wax,
- Figure 4 is a cross-section view taken along the line 4 i of Figure 3,
- Figure 5 is a view similar to that of Figure 4 with a thm coating of sputtered metal laid down over the wax coating,
- Figure 6 is a view similar to that of Figure 5 with the sputtered metal removed from the raised areas between I the grooves,
- Figure 7 is a view similar to Figure 6 with an additional thickness of a different metal deposited over the sputtered medtal coating within the grooves of the master plate, an
- Figure 8 is a fragmentary perspective view of a completed screen made by the process of the present invention.
- Example for making screens in accordance with the process of the present invention it is desirable to start with a spaced grooves 6.
- the number of grooves per inch may vary widely, as for example 200 to 2000 per inch
- the plate of the present example has an area 3% inches square provided with 720 grooves per inch both horizontally and vertically, crossing each other at right angles. These grooves must be ruled with extreme uniformity for best results and, although their depth and width are subject to considerable variation depending upon the end use of the product, it has been found suitable to use grooves having a depth of 0.1 mil and a width of 0.4 mil.
- glass is preferred as the supporting plate, other hard ceramics may be used.
- the master plate is carefully cleaned so as to remove all surface contamination from within the grooves and the raised areas between the grooves.
- the cleaned plate is then dipped briefly in a solution of beeswax so as to apply a very thin coating 8 of the wax over the entire plate.
- This solution can also be applied by other methods, such as spraying, flowing, or brushing.
- a 75% saturated solution of beeswax in petroleum ether having a boiling point between 30 and 70 C. has been found suitable. Any other volatile solvent for the wax may be used, for example hexane or benzene. With this concentration of wax, it is necessary to make only a single dip of the plate in the solution. If considerably lower concentrations of wax are used, more than one dip may be required.
- Other waxes may be used equally as well as beeswax. For example, waxes ,such as carnauba, paraffin, and montan can be used. Although some waxes are preferred over others for best results,
- any wax may be used. It is desirable to use a highly volatile solvent for applying the wait so that wax coating will dry rapidly without dust settling on the surface.
- the thickness of the wax coating 8 is somewhat more critical. In general. a thickness of less than 1 micron should be used for making screens for camera tubes. It is. of course, obvious that a thick coating of wax would completely mask the fine grooves and prevent any subsequent electro-deposition in the form of a grid work of lines. For this reason. it is apparent that the thickness of the wax coating should be less than the depth of the grooves.
- the solvent is evaporated from the wax coating by exposure to the atmosphere and the master is next given a thin coating 10 of sputtered metal over the entire waxcoated surface.
- the master plate is placed inside a conventional'evacuable bell jar for the sputtering operation.
- the sputtering operation is carried out using a cathode of solid metal palladium.
- the solid palladium electrode is preferred, a cathode coated with a suspension of metal having a composition one part bismuth, seven parts palladium. and twenty-five parts gold may be used.
- thesputtering process is substantially the same as that described in the previously referred to U. S. Patent 2.529.086.
- the wax coated surface of the glass plates placed two to four inches from the cathode, the bellar is evacuated to a pressure of 0.1 mm. of mercury (air atmosphere) and a glow discharge is created at about 2500 volts and about 60 ma. These conditions are not 'filaments joined together at their intersections.
- the pressure inside the bell-jar may vary from about 0.03 to 0.3 mm. and sputtering voltages of about 1000 to 2500 volts and currents of about to 70 ma. may be used.
- the sputtering process is carried on for about four minutes although this maybe varied considerably. Usually. sputtering times of 2 to 6 minutes are sufficient.
- the thickness of the palladium coating is such that the transmission of white light through the glass plate is reduced from 85%, before s uttering starts to 40%. after sputternig is com lete.
- the thickness of the coating is so small that it is difficult to measure by usual methods.
- the coating thickness is just enough to provide an electrically conducting film over the wax. Like the wax coating, althou h the thickness may vary, it must be less than the depth of the grooves.
- the glass master plate which has now been provided with a thin coatin of wax 8 and a thin coatin of sputtered palladium 10. is removed from the bell-jar and placed in a dish of distilled water. While submer ed in the distilled water, the coated surface of the plate is rubbed gently so as to remove all of the palladium metal from the raised areas 12 between the grooves (see Fi ure 6) leaving only those portions of the metal 10' which have been de osited in the rooves on top of the wax. In this step of the process, the wax coating in the raised areas between the grooves is also partially removed althou h whether this is removed or not does not matter.
- the plating bath may be one suitable for depositing nickel. and this may consist essentially of 280 grams per liter of nickel sulfate having a composition NiSO4.7H2O, 180 grams per liter of nickel ch oride having the composition NiClv.6HzO, 35 grams per liter of boric acid and enough sulphuric acid to adiust the pH of the solution to 4.0.
- the pH of the solution should be kept between about 4.0 and 5.0 during the plating operation for best results.
- the completed screen 16 is a grid work of m trtilill e screen is flushed with acetone and is dried by placing between two sheets of bond paper in a current of clean dry air. For rapid drying, the air may be somewhat above room temperature.
- a 720 mesh screen made by this process has from about 40%85% light transmission value-depending upon the width of the grooves selected and the amount of metal electro-deposited to form the screen.
- the screen has a light transmission of about 50%.
- plating bath may be made by dissolving 300 grams of copper sulfate (CuSOaSHzO) per liter of water and adiusting the pH to a value of 1.0 by adding sulphuric acid. A screen may be formed in this bath by electroplating using a current density of 0.2 amp. per square inch.
- CuSOaSHzO copper sulfate
- gold or platinum may be used although palladium is preferred.
- a method of making a fine mesh metallic screen which comprises in combination the steps of applying to a glass master plate ruled with a network of horizontal 1 and vertical grooves, there being about 720 grooves per inch in each direction, a solution of beeswax suspended in petroleum ether, evaporating said solvent and thereby forming a thin film of beeswax on the surface of said plate, the thickness of said wax layer being less than the depth of said grooves, sputtering'onto the surface of said wax a film of palladium, in a vacuum by an electrical discharge from a solid electrode of said metal, removing substantially all of said wax and sputtered metal only from the elevated areas of said plate, electrodepositing nickel metal over the sputtered metal remaining in said grooves, and separating the formed screen from said master plate.
Description
Fb. 15 1955 b. J. DONAHUE EIAL 2,702,270
mom for MAKING FINE MESH METALLIC SCREENS Filed June '7, 1952 LE-XHNDER M. RENNIE- 5mm. J. D [manua- United States Patent 2,702,270 METHOD OF MAKING FINE MESH METALLIC SCREENS Daniel I. Donahue, Lancaster, and Alexander M. Rennie, Landisville, Pa uslgnors to Radio Corporation of America, a corporation of Delaware Application June 7, 1952, Serial No. 292,354 8 Claim!- (Cl- 204-11) The resent invention relates to an improved method of making metallic screens of very fine mesh and having a gossamer-like thinness.
Although screens made by the method of the present invention can be used for any desired purpose, one of the applications for which they are particularly designed is that of an electrodein television camera tubes. Screens used in television camera tubes are required to be extremely uniform, be of very fine mesh, capable of being stretched taut without curling, and also be of relattvely high electron permeability and light permeability.
In the past, metal screens of fine mesh have been made by a number of difierent methods. One of these methods was to make the screen of woven wire of extreme thinness. This method has proven generally unsatisfactory because of the difiiculty of carrying it out and because of the non-uniformity of the product made. Such screens also have relatively low light transmission and electron transmission values. Another method formerly used has involved the electro-deposition of metal upon conductive parts of a pattern made with the aid of a light sensitive emulsion. In general, screens made by this method have proven unsatisfactory for about the same reasons as woven wire screens.
Another previous method of making fine mesh metal screens is described in U. S. Patent 2,529,086 issued November 7, 1950, to H. B. Law. By this method, screens can be made which are entirely satisfactory for use in television camera tubes. However, it has been found that the method is difficult to control so as to obtain uniform results. One of the difiiculties in the formerly patented process is that a sputtered metal coating is used, this sputtered metal being deposited from a cathode painted with a suspension of a mixture of the metals, palladium, gold, and bismuth. In practice, it has proven diflicult to coat this suspension uniformly on the cathode in exactly the same way each time and to deposit a sputtered coating in such a way that perfect metal deposits can be made over it. Also, the screen which is made by this method has a considerable tendency to curl and tear at various points unless extreme care is taken in production.
The present invention is an improvement in the method described in the above-mentioned patent. It is much easier to use in factory production and produces screens of greater uniformity and more satisfactory texture. In general, the improved method of the present invention comprises the steps of depositing a very thin coating of wax over the entire surface of a hard ceramic master plate which has previously been provided with a grid work of etched grooves having a spacing such as required in the finished screen, depositing a thin layer of a metal such as palladium, platinum, or gold on top of the wax coating by a sputtering process, removing all of the sputtered metal coating from the raised areas between the etched. grooves, electro-depositing another metal over the sputtered metal coating in the grooves so as to form a grid work or screen of metal, and separating the formed screen from the coated ceramic master plate.
One object of the present invention is to provide an improved method of making fine mesh metallic screens.
Another object of the present invention is to provide a method of making fine mesh screens which are less susceptible to curling and tearing.
Another object of the invention is to provide an improved method of making very fine mesh metallic screens 2,702,270 Patented Feb. 15, 1955 in which the product is more uniform than in previously used processes.
Another object of the present invention is to provide an improved method of making fine mesh screens which is more practical in ordinary factory production.
Another object of the present invention is to provide an improved method of making fine mesh screens which enables the elimination of certain factors which, in the past, have proven very difiicult to control.
Another object of the invention is to provide an improved method of making fine mesh screens which enables the re-use of glass masters formerly discarded because of slight surface imperfections.
. These and other objects will be more apparent and the invention will be more readily understood from the following detailed description and the accompanying drawings of which,
Figure 1 1s a perspective view of a glass master plate or matrix having on one surface a grid work of fine grooves corresponding in number and width to the metal screen which is to be the final product,
Figure 2 is a magnified fragmentary view of part of the screen portion of the master plate of Figure 1,
Figure 3 is a view like that of Figure 2, the portion of the plate shown being coated with a thin film of wax,
Figure 4 is a cross-section view taken along the line 4 i of Figure 3,
Figure 5 is a view similar to that of Figure 4 with a thm coating of sputtered metal laid down over the wax coating,
Figure 6 is a view similar to that of Figure 5 with the sputtered metal removed from the raised areas between I the grooves,
Figure 7 is a view similar to Figure 6 with an additional thickness of a different metal deposited over the sputtered medtal coating within the grooves of the master plate, an
Figure 8 is a fragmentary perspective view of a completed screen made by the process of the present invention.
A preferred example of making a screen in accordance with the improved process of the present invention will now be given.
Example For making screens in accordance with the process of the present invention, it is desirable to start with a spaced grooves 6. Although the number of grooves per inch may vary widely, as for example 200 to 2000 per inch, the plate of the present example has an area 3% inches square provided with 720 grooves per inch both horizontally and vertically, crossing each other at right angles. These grooves must be ruled with extreme uniformity for best results and, although their depth and width are subject to considerable variation depending upon the end use of the product, it has been found suitable to use grooves having a depth of 0.1 mil and a width of 0.4 mil. Although glass is preferred as the supporting plate, other hard ceramics may be used.
The master plate is carefully cleaned so as to remove all surface contamination from within the grooves and the raised areas between the grooves. The cleaned plate is then dipped briefly in a solution of beeswax so as to apply a very thin coating 8 of the wax over the entire plate. This solution can also be applied by other methods, such as spraying, flowing, or brushing. A 75% saturated solution of beeswax in petroleum ether having a boiling point between 30 and 70 C. has been found suitable. Any other volatile solvent for the wax may be used, for example hexane or benzene. With this concentration of wax, it is necessary to make only a single dip of the plate in the solution. If considerably lower concentrations of wax are used, more than one dip may be required. Other waxes may be used equally as well as beeswax. For example, waxes ,such as carnauba, paraffin, and montan can be used. Although some waxes are preferred over others for best results,
the use of a particular wax is not critical and, in general,
any wax may be used. It is desirable to use a highly volatile solvent for applying the wait so that wax coating will dry rapidly without dust settling on the surface.
The thickness of the wax coating 8 is somewhat more critical. In general. a thickness of less than 1 micron should be used for making screens for camera tubes. It is. of course, obvious that a thick coating of wax would completely mask the fine grooves and prevent any subsequent electro-deposition in the form of a grid work of lines. For this reason. it is apparent that the thickness of the wax coating should be less than the depth of the grooves.
The solvent is evaporated from the wax coating by exposure to the atmosphere and the master is next given a thin coating 10 of sputtered metal over the entire waxcoated surface. The master plate is placed inside a conventional'evacuable bell jar for the sputtering operation. The sputtering operation is carried out using a cathode of solid metal palladium. Although the solid palladium electrode is preferred, a cathode coated with a suspension of metal having a composition one part bismuth, seven parts palladium. and twenty-five parts gold may be used. With the exception of ditference in the preferred sputtering metal. thesputtering process is substantially the same as that described in the previously referred to U. S. Patent 2.529.086. The wax coated surface of the glass plates placed two to four inches from the cathode, the bellar is evacuated to a pressure of 0.1 mm. of mercury (air atmosphere) and a glow discharge is created at about 2500 volts and about 60 ma. These conditions are not 'filaments joined together at their intersections.
critical and will vary greatly depending on the size of the apparatus and the area to be sputtered. For example. the pressure inside the bell-jar may vary from about 0.03 to 0.3 mm. and sputtering voltages of about 1000 to 2500 volts and currents of about to 70 ma. may be used.
The sputtering process is carried on for about four minutes although this maybe varied considerably. Usually. sputtering times of 2 to 6 minutes are sufficient. In the present example. the thickness of the palladium coating is such that the transmission of white light through the glass plate is reduced from 85%, before s uttering starts to 40%. after sputternig is com lete. The thickness of the coating is so small that it is difficult to measure by usual methods. The coating thickness is just enough to provide an electrically conducting film over the wax. Like the wax coating, althou h the thickness may vary, it must be less than the depth of the grooves.
The glass master plate which has now been provided with a thin coatin of wax 8 and a thin coatin of sputtered palladium 10. is removed from the bell-jar and placed in a dish of distilled water. While submer ed in the distilled water, the coated surface of the plate is rubbed gently so as to remove all of the palladium metal from the raised areas 12 between the grooves (see Fi ure 6) leaving only those portions of the metal 10' which have been de osited in the rooves on top of the wax. In this step of the process, the wax coating in the raised areas between the grooves is also partially removed althou h whether this is removed or not does not matter.
After the rubbing step, the plate is rinsed with water and placed in a plating bath in order to have a further thickness of metal 14 deposited in the grooves. The plating bath may be one suitable for depositing nickel. and this may consist essentially of 280 grams per liter of nickel sulfate having a composition NiSO4.7H2O, 180 grams per liter of nickel ch oride having the composition NiClv.6HzO, 35 grams per liter of boric acid and enough sulphuric acid to adiust the pH of the solution to 4.0. The pH of the solution should be kept between about 4.0 and 5.0 during the plating operation for best results.
In=this bath the coated plate is subjected to the electrodeposition of metal for about eight minutes at a current densitv of .16 amp. per square inch. When the electro-' deposition is complete, the master plate will now have a deposit of nickel 14 in all of the grooves on top of the palladium film. The plate is next rinsed in distilled water and the metal screen 16 is floated free of the glass plate. When the screen is made of electro-deposited nickel, the palladium metal usually stays on the nickel so that the screen separates from the master plate at the surface of.
from the wax without any tearing and, for some reason not understood, the screen develops free of strain and does not have nearly as much tendency to curl and tear as do screens using previously used processes.
As shown in Figure 8, the completed screen 16, after removal from the glass plate, is a grid work of m trtilill e screen is flushed with acetone and is dried by placing between two sheets of bond paper in a current of clean dry air. For rapid drying, the air may be somewhat above room temperature.
A 720 mesh screen made by this process has from about 40%85% light transmission value-depending upon the width of the grooves selected and the amount of metal electro-deposited to form the screen. In the example described, the screen has a light transmission of about 50%.
Although nickel has been given as the electro-deposited metal in the above example. any metal capable of forminga coherent deposit under electro-deposition can be used. Other suitable metals are copper, silver, zinc, and platinum, but it is to be understood that these are only given as examples. Compositions of the plating bath are not critical. bath may be made by dissolving 300 grams of copper sulfate (CuSOaSHzO) per liter of water and adiusting the pH to a value of 1.0 by adding sulphuric acid. A screen may be formed in this bath by electroplating using a current density of 0.2 amp. per square inch.
For the sputtering metal, gold or platinum may be used although palladium is preferred.
There has thus been described an improved method of making fine mesh screens for any desired purpose where very thin screens having relatively high light or electron transmission are required. The screens, themselves, are
much improved in quality because of the presence of which comprises in combination the steps of applying to a ceramic master plate ruled with a network of grooves a solution of wax suspended in a volatile solvent. evaporating said solvent and thereby forming a thin film of wax on the surface of said plate the thickness of said wax layer being less than the depth of said grooves. sputtering onto the surface of said wax a film of at least one metal selected from the group consisting of gold. platinum and palladiumin a vacuum by an electrical discharge from a solid electrode of said metal. removing substantially all of said wax and sputtered metal only from the elevated areas of said plate. electrodeoositing additional metal over the sputtered metal remaining in said grooves, and separating the formed screen from said master late.
2. A method of making a fine mesh metallic screen which comprises in combination the steps of applying to a glass master plate ruled with a network of horizontal 1 and vertical grooves, there being about 720 grooves per inch in each direction, a solution of beeswax suspended in petroleum ether, evaporating said solvent and thereby forming a thin film of beeswax on the surface of said plate, the thickness of said wax layer being less than the depth of said grooves, sputtering'onto the surface of said wax a film of palladium, in a vacuum by an electrical discharge from a solid electrode of said metal, removing substantially all of said wax and sputtered metal only from the elevated areas of said plate, electrodepositing nickel metal over the sputtered metal remaining in said grooves, and separating the formed screen from said master plate.
3. The method of claim 1 in which said sputtered metal is palladium.
4. The method of claim 1 in which said sputtered metal is gold.
5. The method of claim 1 in which the number of said grooves is at least 500 per inch.
6. The method of claim 1 in which said sputtered metal coating is platinum.
7. The method 'of claim 1 in which said electro-dee posited metal is nickel.
If copper is the plating metal, a suitable References Cited in the file of this patent 5 634,376 UNITED STATES PATENTS Callow Mar. 10, 1885 Law Nov. 7, 1950 6 FOREIGN PATENTS Great Britain 1891 Great Britain Jan. 25, 1937 Great Britain Mar. 22, 1950
Claims (1)
1. A METHOD OF MAKING A FINE MESH METALLIC SCREEN WHICH COMPRISES IN COMBINATION THE STEPS OF APPLYING TO A CERAMIC MASTER PLATE RULED WITH A NETWORK OF GROOVES A SOLUTION OF WAX SUSPENDED IN A VOLATILE SOLVENT, EVAPORATING SAID SOLVENT AND TEHREBY FORMING A THIN FILM OF WAX ON THE SURFACE OF SAID PLATE THE THICKNESS OF SAID WAX LAYER BEING LESS THAN THE DEPTH OF SAID GROOVES, SPUTTERING ONTO THE SURFACE OF SAID WAX A FILM OF AT LEAST ONE METAL SELECTED FROM THE GROUP CONSISTING OF GOLD, PLATINUM AND PALLADIUM IN A VACUUM BY AN ELECTRICAL DISCHARGE FROM A SOLID ELECTRODE OF SAID METAL, REMOVING SUBSTANTIALLY ALL OF SAID WAX AND SPUTTERED METAL ONLY FROM THE ELEVATED AREAS OF SAID PLATE, ELECTRODEPOSITION ADDITIONAL METAL OVER THE SPUTTERED METAL REMAINING IN SAID GROOVES, AND SEPARATING THE FORMED SCREEN FROM SAID MASTER PLATE.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US292354A US2702270A (en) | 1952-06-07 | 1952-06-07 | Method of making fine mesh metallic screens |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US292354A US2702270A (en) | 1952-06-07 | 1952-06-07 | Method of making fine mesh metallic screens |
Publications (1)
Publication Number | Publication Date |
---|---|
US2702270A true US2702270A (en) | 1955-02-15 |
Family
ID=23124299
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US292354A Expired - Lifetime US2702270A (en) | 1952-06-07 | 1952-06-07 | Method of making fine mesh metallic screens |
Country Status (1)
Country | Link |
---|---|
US (1) | US2702270A (en) |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2762762A (en) * | 1953-02-27 | 1956-09-11 | Rca Corp | Method for electroforming a copper article |
US2847370A (en) * | 1956-09-18 | 1958-08-12 | Chas D Briddell Inc | Method of ornamentation |
US3102847A (en) * | 1957-07-23 | 1963-09-03 | Csf | Storage tube targets |
US3197390A (en) * | 1962-07-02 | 1965-07-27 | Norman B Mears | Screen grid for power tubes and method of making the same |
US3434939A (en) * | 1965-10-07 | 1969-03-25 | Fabri Tek Inc | Process for making printed circuits |
FR2208001A1 (en) * | 1972-11-28 | 1974-06-21 | Buser Ag Maschf Fritz | |
US3833482A (en) * | 1973-03-26 | 1974-09-03 | Buckbee Mears Co | Matrix for forming mesh |
US4184925A (en) * | 1977-12-19 | 1980-01-22 | The Mead Corporation | Solid metal orifice plate for a jet drop recorder |
US4229265A (en) * | 1979-08-09 | 1980-10-21 | The Mead Corporation | Method for fabricating and the solid metal orifice plate for a jet drop recorder produced thereby |
US6794056B1 (en) * | 1999-09-22 | 2004-09-21 | Nord Impianti S.R.L. | Laminar structure |
CN1311976C (en) * | 2001-04-09 | 2007-04-25 | 惠普公司 | Reusable core for making ink jetting orifice plate |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US313805A (en) * | 1885-03-10 | Process of manufacturing perforated metallic goods | ||
GB471810A (en) * | 1936-03-09 | 1937-09-09 | Herbert Edward Holman | Improvements in and in the manufacture of metal mesh screens |
GB634376A (en) * | 1946-11-27 | 1950-03-22 | Herbert Edward Holman | Improvements relating to a method of producing metal mesh screens such as are suitable for use in television transmission tubes |
US2529086A (en) * | 1946-04-30 | 1950-11-07 | Rca Corp | Method of making fine mesh screens |
-
1952
- 1952-06-07 US US292354A patent/US2702270A/en not_active Expired - Lifetime
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US313805A (en) * | 1885-03-10 | Process of manufacturing perforated metallic goods | ||
GB471810A (en) * | 1936-03-09 | 1937-09-09 | Herbert Edward Holman | Improvements in and in the manufacture of metal mesh screens |
US2529086A (en) * | 1946-04-30 | 1950-11-07 | Rca Corp | Method of making fine mesh screens |
GB634376A (en) * | 1946-11-27 | 1950-03-22 | Herbert Edward Holman | Improvements relating to a method of producing metal mesh screens such as are suitable for use in television transmission tubes |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2762762A (en) * | 1953-02-27 | 1956-09-11 | Rca Corp | Method for electroforming a copper article |
US2847370A (en) * | 1956-09-18 | 1958-08-12 | Chas D Briddell Inc | Method of ornamentation |
US3102847A (en) * | 1957-07-23 | 1963-09-03 | Csf | Storage tube targets |
US3197390A (en) * | 1962-07-02 | 1965-07-27 | Norman B Mears | Screen grid for power tubes and method of making the same |
US3434939A (en) * | 1965-10-07 | 1969-03-25 | Fabri Tek Inc | Process for making printed circuits |
FR2208001A1 (en) * | 1972-11-28 | 1974-06-21 | Buser Ag Maschf Fritz | |
US3833482A (en) * | 1973-03-26 | 1974-09-03 | Buckbee Mears Co | Matrix for forming mesh |
US4184925A (en) * | 1977-12-19 | 1980-01-22 | The Mead Corporation | Solid metal orifice plate for a jet drop recorder |
US4229265A (en) * | 1979-08-09 | 1980-10-21 | The Mead Corporation | Method for fabricating and the solid metal orifice plate for a jet drop recorder produced thereby |
US6794056B1 (en) * | 1999-09-22 | 2004-09-21 | Nord Impianti S.R.L. | Laminar structure |
CN1311976C (en) * | 2001-04-09 | 2007-04-25 | 惠普公司 | Reusable core for making ink jetting orifice plate |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2702270A (en) | Method of making fine mesh metallic screens | |
US2166367A (en) | Process for the production of metallic screens | |
Schaefer et al. | Surface replicas for use in the electron microscope | |
US3419901A (en) | Method for producing flakes of nickel | |
JPH0253518B2 (en) | ||
US3878061A (en) | Master matrix for making multiple copies | |
US2435889A (en) | Production of metallic designs on nonmetallic materials | |
US3275466A (en) | Method of adhering particles to a support surface | |
DE2453035B2 (en) | Method for applying a metallic layer in the form of a pattern on an inert substrate coated with a first thin metallic layer | |
US2646396A (en) | Method of making electroformed articles | |
US2217334A (en) | Screen for electro-optical device and method of preparing it | |
DE1690276C2 (en) | Cathode sputtering process for producing ohmic contacts on a silicon semiconductor substrate and apparatus for carrying out the process | |
US2225734A (en) | Electrolytic method of making screens | |
US2529086A (en) | Method of making fine mesh screens | |
US2793178A (en) | Method of providing insulator with multiplicity of conducting elements | |
US2115855A (en) | Cathode ray tube | |
US3006821A (en) | Manufacture of silver chloride electrodes | |
US2805986A (en) | Method of making fine mesh screens | |
US3833482A (en) | Matrix for forming mesh | |
US3342706A (en) | Method of constructing evaporation masks | |
US2221502A (en) | Process of forming screens | |
US2123297A (en) | Process of preparing perforated metal articles | |
US2230868A (en) | Method of manufacturing reticulated metal sheets | |
US1807875A (en) | Method of electroplating and product thereof | |
US2874449A (en) | Method of providing an electrically conductive network on a support of insulating material |