United States Patent Office
`Unite States Patent
`1
`1
`
`I .
`
`2,990,282
`2,990,282 _
`Patented June 27, 1961
`Patented June 27, 1961
`
`2
`2
`pared solution, an enlarged view of the design, which
`pared solution, an enlarged view of the design, which
`2,990,282
`will ultimately be reproduced on the molybdenum plate,
`2,990,282
`Will ultimately be reproduced on the molybdenum plate,
`METHOD OF ETCHING AND COMPOSITION
`is drawn, for example, on paper, the portions which are
`METHOD OF ETCHING AND COMPOSITION
`is drawn, for example, on paper, the portions which are
`THEREFOR
`THEREFOR
`desired to remain being made opaque by blackening. The
`desired to remain being made opaque by blackening. The
`Warner C. Wicke, R.D. 3, Valleyview Ave.,
`Warner C. Wicke, RD. '3, Valleyview Ave.,
`8 entire design, including the blackened portions, is photo­
`entire design, including the blackened portions, is photo
`Schenectady, N.Y.
`Schenectady, N.Y.
`graphically reduced to required size and a negative of the
`graphically reduced to required size and a negative of the
`No Drawing. Original application Oct. 29,1958, Ser. No.
`No Drawing. Original application Oct. 29, 1958, Ser. No.
`design obtained. The molybdenum plate, which may be
`design obtained. The molybdenum plate, which may be
`770,570. Divided and this application Aug. 4, 1959,
`770,570. Divided and this application Aug. 4, 1959,
`of the order of 0.001 inch thickness is then coated with
`Ser. No. 838,375
`of the order of 0.001 inch thickness is then coated with
`Ser. No. 838,375
`a photosensitive glue or shellac which contains a substance
`1 Claim.
`(CI. 96—36)
`1 Claim. (Cl. 96—36)
`a photosensitive glue or shellac which contains a substance
`10 providing an acid insolubilizing agent upon exposure to
`10
`providing an acid insolubilizing agent upon exposure to
`This invention relates to the etching of metals and more
`light such as a bichromate. The negative is then super­
`This invention relates to the etching of metals and more
`light such as a bichromate. The negative is then super
`particularly to etching compositions and the manner of
`imposed over the coated plate and exposed directly to
`particularly to etching compositions and the manner of
`imposed over the coated plate and exposed directly to
`etching molybdenum plates to produce electronic grids
`etching molybdenum plates to produce electronic grids
`light for a length of time sufficient for the design or pat­
`light for a length of time suf?cient for the design or pat
`and the like of irregular design. This application is a
`tern to be reproduced on the surface of the molybdenum
`and the like of irregular design. This application is a
`tern to be reproduced on the surface of the molybdenum
`division of application Serial No. 770,570, filed October 15 plate. The portions of the shellac or glue which have
`division of application Serial No. 770,570, ?led October
`plate. The portions of the shellac or glue which have
`29, 1958, for Acid Etching of Molybdenum.
`been acted upon by the light will become insolubilized to
`29, 1958, for Acid Etching of Molybdenum.
`been acted upon by the light will become insolubilized to
`In a conventional method of making electronic grids
`acid, while the remaining portion will be soluble and can
`In a conventional method of making electronic grids
`acid, while the remaining portion will be soluble and can
`and the like, a photosensitive coating or film is applied
`be removed by rubbing, brushing or sponging or dissolved
`and the like, a photosensitive coating or ?lm is applied
`be removed by rubbing, brushing or sponging or dissolved
`to the surface of metals and the coated surface is exposed
`away by alkali or otherwise removed from the plate leav-
`to the surface of metals and the coated surface is exposed
`away by alkali or otherwise removed from the plate leav
`to light through a negative having an image thereon so as 20 ing the molybdenum plate exposed,
`The molybdenum
`to light through a negative having an image thereon so as
`20
`ing the molybdenum plate exposed. The molybdenum
`to produce a corresponding image on the coating. The
`plate is then etched by applying the above prepared solu­
`to produce a corresponding image on the coating. The
`plate is then etched by applying the above prepared solu
`exposed coated surface is "developed" forming an acid
`tion or mixture directly and according to conventional
`exposed coated surface is “developed” forming an acid
`tion or mixture directly and according to conventional
`resistant coating in the form of the image produced by
`etching methods to form the desired electronic elements
`resistant coating in the form of the image produced by
`etching methods to form the desired electronic elements
`the exposure. The acid resistant coating or resist is usu­
`from the molybdenum plate. The remaining resist ma-
`the exposure. The acid resistant coating or resist is usu
`from the molybdenum plate. The remaining resist ma
`ally further subjected to a hardening treatment which in- 25 terial is removed in an alkali solution and the etched
`ally further subjected to a hardening treatment which in
`25
`terial is removed in an alkali solution and the etched
`creases its resistance to the etching acid. The prepared
`plate allowed to dry.
`creases its resistance to the etching acid. The prepared
`plate allowed to dry.
`metal surface or resist is then subjected to etching by
`An electrolytic etching bath or composition for produc­
`metal surface or resist is then subjected to etching by
`An electrolytic etching bath or composition for produc
`suitable acid.
`ing molybdenum grids or other electronic elements is
`suitable acid.
`ing molybdenum grids or other electronic elements is
`The etching is usually carried out with nitric acid suit-
`formulated by mixing together the following three in-
`The etching is usually carried out with nitric acid suit
`formulated by mixing together the following three in
`ably diluted with water and the acid solution may be 30 gredients in the stated proportions by volume:
`ably diluted with water and the acid solution may be
`30
`gredients in the stated proportions by volume:
`splashed or otherwise impinged against the surfaces of
`The bath consists of 34 percent sulphuric acid reckoned
`splashed or otherwise impinged against the surfaces of
`The bath consists of 34 percent sulphuric acid reckoned
`object being etched. The acid solution attacks the bare
`as 100 percent H2SO4, 42 percent of orthophosphoric acid
`object being etched. The acid solution attacks the bare
`as 100 percent H2804, 42 percent of orthophosphoric acid
`portions of the metal, that is, the portions of the metal
`reckoned as 100 percent 2H3P04.H20 and 24 percent of
`portions of the metal, that is, the portions of the metal
`reckoned as 100 percent 2H3PO4.H2O and 24 percent of
`object denuded of the photosensitive material in the de-
`_
`_
`distilled water. These ingredients are agitated together
`object denuded of the photosensitive material in the de
`distilled water. These ingredients are agitated together
`veloping operation. The rest of the metal surface is pro- 38 for several minutes to insure a uniform mixture or solu-
`veloping operation. The rest of the metal surface is pro
`35
`for several minutes to insure a uniform mixture or solu
`tected by the coating or resist from direct attack by the
`don.
`tected by the coating or resist from direct attack by the
`tion.
`acid and does not become etched while as the etching
`The molybdenum plate, prepared similarly as described
`acid and does not become etched while as the etching
`The molybdenum plate, prepared similarly as described
`proceeds, metal from the base portions of the object which
`heretofore, is immersed in the electrolytic etching bath
`proceeds, metal from the base portions of the object which
`heretofore, is immersed in the electrolytic etching bath
`are not coated dissolve away leaving the metal covered
`_
`_
`solution and wires from the poles of a battery, or any
`are not coated dissolve away leaving the metal covered
`solution and wires from the poles of a battery, or any
`by the image. Before a sigmficant amount of the metal 40 sujta]3je direct current source, are placed in the bath with
`by the image. Before a signi?cant amount of the metal
`40
`suitable direct current source, are placed in the bath with
`forming the image can be dissolved away by lateral at-
`the molybdenum plate attached to the positive wire and
`forming the image can be dissolved away by lateral at
`the molybdenum plate attached to the positive wire and
`tack, it is conventional practice to rinse off the etching
`made anodic, while a suitable metal electrode, or cath-
`tack, it is conventional practice to rinse oif the etching
`made anodic, while a suitable metal electrode, or cath
`solution, dry the rinsed object, and then treat the dried
`ode, is attached to the other wire to efiect the etching of
`solution, dry the rinsed object, and then treat the dried
`ode, is attached to the ‘other wire to effect the etching of
`object so as to protect the metal image from lateral at-
`the molybdenum to form the electronic grids by removing
`object so as to protect the metal image from lateral at
`the molybdenum to form the electronic grids by removing
`tack by the acid before proceeding with a further etching 45 the molybdenum from the anode and deposited on the
`tack by the acid before proceeding with a funther etching
`the molybdenum from the anode and deposited on the
`45
`operation. Or, if desired, the base metal plate may also
`cathode. Since the molybdenum plate is provided with
`operation. Or, if desired, the base metal plate may also
`cathode. Since the molybdenum plate is provided with
`be coated with resist on the other side.
`_
`_
`a resist pattern on its surface which is unaffected by the
`be coated with resist on the other side.
`a resist pattern on its surface which is unaffected by the
`Molybdenum is a refractory metal and being softer and
`bath solution, only molybdenum will be removed from the
`Molybdenum is a refractory metal and being softer and
`bath solution, only molybdenum will be removed from the
`more ductile than other metals such as tungsten has found
`exposed surface of the anode and the remaining portion
`more ductile than other metals such as tungsten has found
`exposed surface of the anode and the remaining portion
`widespread use in filaments, grids, screens, and the like 50 of the plate will form the electronic grid,
`widespread use in ?laments, grids, screens, and the like
`of the plate Will form the electronic grid.
`50
`but heretofore has not been satisfactorily etched to pro­
`What is claimed is:
`but heretofore has not been satisfactorily etched to pro
`What is claimed is:
`duce such elements.
`_
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`duce such elements.
`A method of producing electronic grids from a thin
`Accordingly, it is the broad object of this invention to
`molybdenum plate which comprises the steps of coating
`Accordingly, it is the broad object of this invention to
`molybdenum plate which comprises the steps of coating
`provide a direct etching bath or composition, which is
`said molybdenum plate with photosensitive resist mate-
`provide a direct etching bath or composition, which is
`said molybdenum plate with photosensitive resist mate
`adapted particularly for etching.
`adapted particularly for etching.
`55 rial, applying a photographic negative of a desired grid
`rial, applying a photographic negative of a desired grid
`55
`A more specific object of this invention is directed to
`design to the resist material, exposing the assembly to
`A more speci?c object of this invention is directed to
`design to the resist material, exposing the assembly to
`an electrolytic process for etching molybdenum to produce
`light to provide acid insoluble areas beneath the negative
`an electrolytic process for etching molybdenum to produce
`light to provide acid insoluble areas beneath the negative
`electronic grids.
`electronic grids.
`which outline the desired grid design and other acid solu-
`which outline the desired grid design and other acid solu
`In accordance with one aspect of the invention, an etch-
`ble areas, removing the photosensitive resist from said
`In accordance with one aspect of the invention, an etch—
`ble areas, removing the photosensitive resist from said
`ing bath is prepared by mixing together nitric acid, sul- go other acid soluble areas by washing to provide the plate
`ing bath is prepared by mixing together nitric acid, sul
`other acid soluble areas by washing to provide the plate
`60
`phnric acid and distilled water and is used for the chemi­
`with bare surfaces, then subjecting the thus bared sur­
`phuric acid and distilled water and is used for the chemi
`with bare surfaces, then subjecting the thus bared sur
`cal etching of molybdenum plates.
`cal etching of molybdenum plates.
`faces of the plate to the direct action of a chemical bath
`faces of the plate to the direct action of a chemical bath
`This etching bath consists of a mixture of 33VS percent
`containing by volume one-third concentrated sulphuric
`This etching bath consists of a mixture of 331/3 percent
`containing by volume one-third concentrated sulphuric
`of concentrated sulphuric acid, and 3316 percent of con­
`acid, one-third concentrated nitric acid and the balance
`of concentrated sulphuric acid, and 33% percent of con
`acid, one-third concentrated nitric acid and the balance
`centrated nitric acid to which is added 3316 percent of 05 of distilled water,
`centrated nitric acid to which is added 331/3 percent of
`of distilled water.
`65
`distilled water, or the distilled water may be used as a
`distilled water, or the distilled water may be used as a
`diluent for the sulphuric acid so that a suitably dilute
`References Cited in the file of this patent
`diluent for the sulphuric acid so that a suitably dilute
`References Cited in the ?le of this patent
`aqueous sulphuric acid solution is provided before the
`aqueous sulphuric acid solution is provided before the
`Mertle: Chemical Abstracts, January 20, 1943, p. 320.
`Mertle: Chemical Abstracts, January 20, 1943, p. 320.
`addition of the nitric acid. The mixture of these ingre­
`addition of the nitric acid. The mixture of these ingre
`Rhodes et al.: Ind. Eng. Chem. February 1929, pp.
`Rhodes et al.: Ind. Eng. Chem. February 1929, pp.
`dients is agitated for several minutes to insure a uniform 70
`dients is agitated for several minutes to insure a uniform
`142-150.
`70
`l42-150.
`etching bath solution.
`etching bath solution.
`Lange's Handbook of Chemistry, 8th ed., p. 988.
`Lange’s Handbook of Chemistry, 8th ed., p. 988.
`In order to form electronic grids by using the above pre-
`In order to form electronic grids by using the above me
`
`
`
`ChinaStar Ex.1009
`
`

`
`UNITED STATES PATENT OFFICE
`UNITED STATES PATENT OFFICE
`CERTIFICATION OF CORRECTION
`CERTIFICATION OF CORRECTION
`June 2 7 . 1962
`Patent No. 2,990,282
`Patent No. 2,990,282
`_ June 27, 1962
`
`-
`
`'
`
`’
`
`Warner C . Wicke
`Warner C. Wicke
`
`It is hereby certified that error appears in the above numbered pat­
`It is hereby certified that error appears in the above numbered pat
`ent requiring correction and that the said Letters Patent should read as
`ent requiring correction and that the said Letters Patent should read as‘
`corrected below.
`corrected below.
`I
`
`I n t h e g r a n t , l i n e s 1 t o 3 , f o r "Warner C„ Wicke, of
`In the grant, lines I to 3, for HWarner C; Wicke, of
`Schenectady, New Y o r k , " r e a d — Warner C . Wicke, of Schenectady,
`Schenectady, New York,"-;read —— Warner C. Wicke', of Schenectady,
`New York, a s s i g n o r , by mesne a s s i g n m e n t s , t o United S t a t e s of
`New York, assignor, by mesne assignments, to United States of
`America a s r e p r e s e n t e d by t h e S e c r e t a r y of t h e Navy,
`l i n e
`America as representedby the Secretary of ‘the Navy, =—'—=; ‘line
`1 2 , f o r "Warner C. Wicke, h i s h e i r s o r a s s i g n s " read — United
`12, for "Warner Ca Wicke, his heirs or assigns',’ read -— United
`S t a t e s of America a s r e p r e s e n t e d by t h e S e c r e t a r y of t h e
`States of America as represented by the Secretary of the
`Navy — ; i n t h e heading t o t h e p r i n t e d s p e c i f i c a t i o n , l i n e s
`Navy -—; in the heading to the printed specification, lines
`4 and 5 , f o r "Warner C0 Wicke, R6D. 3 , Valleyview A v e , ,
`4 and 5, for "Warner C,’ Wicke, RSD. 3, Valleyview Ave.,
`S c h e n e c t a d y , N o Y o " read —• Warner C . Wicke, S c h e n e c t a d y ,
`Schenectady, Na Y." read -—-— Warner C. Wicke, Schenectady,
`N0 Y . , a s s i g n o r , by mesne a s s i g n m e n t s , t o United S t a t e s of
`NI Y. , assignor, by mesne assignments, to United States of
`America a s r e p r e s e n t e d by t h e S e c r e t a r y of t h e Navy
`America as represented by the Secretary of the Navy ~~°
`
`Signed and s e a l e d t h i s 1 1 t h day of September 1962.
`Signed and sealed this 11th day of September 1962.,
`
`(SEAL)
`(SEAL)
`Attest:
`Attest:
`ERNEST W . SWIDER
`ERNEST W. SWIDER
`Attesting Officer
`Attesting Officer
`
`I
`
`.
`
`v
`
`v
`
`‘
`
`DAVID L. XADD
`» DAVID L. LADI)
`Commissioner of Patents
`‘Commissioner of Patents.
`
`_
`
`'