US3303320A

US3303320A - Vapor-coating apparatus

Info

Publication number: US3303320A
Application number: US562066A
Authority: US
Inventors: Muller Paul
Original assignee: WC Heraus GmbH and Co KG
Current assignee: WC Heraus GmbH and Co KG
Priority date: 1962-09-25
Filing date: 1966-06-21
Publication date: 1967-02-07
Anticipated expiration: 1984-02-07
Also published as: FR1369712A; DE1199097B

Description

Feb 7, 1967 P. MULLER 3,303,320

VAPOR- COATI NG APPARATUS Original Filed Sept. 10, 1963 2 Sheets-Sheet 1 I 4- f 4 l 8/ 1W im m i j 4 f J3 INVENTOR Pay/Muller ATTORNEY Feb. 7, 1967 P. MULLER VAPOR-COATING APPARATUS Original Filed Sept. 10. 1963 2 Sheets-Sheet 2 VIM- INVENTOR 7 47 u Mu/Aer United States Patent 3,303,320 VAPOR-COATING APPARATUS Paul Muller, Hanan am Main, Germany, assignor to W. C. Heraeus Gesellschaft mit beschrankter Haftung, Hanan am Main, Germany, a corporation of Germany Continuation of application Ser. No. 307,954, Sept. 10, 1963. This application June 21, 1966, Ser. No. 562,066 Claims priority, application Germany, Sept. 25, 1962, H 46,998 8 Claims. (Cl. 219-121) The present invention relates to a vapor-coating apparatus in which a material is heated and vaporized in a vacuum chamber by an electron beam and the vapor is deposited upon an object, and this application is a continuation of my co-pending application Serial No. 307,954 which was filed September 10, 1963.

Apparatus of this general type employing electron beams for heating the material to be vaporized are known for some time. They have several very important advantages over vapor-coating apparatus which employ other heating means, for example, by electric resistance. When heating the material to be vaporized by resistance heating in long vaporizer crucibles, strong heating currents are passed through the liquid material and the outer circuit exerts electrodynamic forces upon the material which very easily cause the liquid material to creep upwardly along the walls and then to flow out of the crucible. Since these electrodynamic forces do not occur when the material is heated in the long vaporizer crucibles by means of electron beams, such spilling of material is avoided. Furthermore, the localized, spotlight heating of the material by means of an electron beam results in a very quick vaporization which tends to prevent a dissociation or disproportionation of certain compounds which occurs when the heating occurs slowly by resistance heating and which may be very undesirable in the coating produced.

The electron beams which are used for vaporizing apparatus are generally focused so as to be of a substantially cylindrical cross section. Such an electron beam heats practically only the relatively small spot where it hits upon the material to be vaporized so that a vaporization also occurs only at this small spot. In order to heat a larger surface area of the material, so-called transverse electron guns have already been developed which instead of substantially cylindrical electron beams produce beams of a substantially rectangular ribbonlike cross section for heating metals to the melting point. Such ribbonlike beams are superior to the cylindrical beams insofar as they permit a vaporizer crucible to be heated longitudinally for a certain distance. These distances are, however, still insufiicient for properly coating wider bands of material by vapor-deposition.

It is an object of the present invention to provide a vapor-coating apparatus of a very simple and inexpensive construction which overcomes the last-mentioned disadvantage and is designed for coating wide bands of materials in a vacuum by heating the vaporizing material by means of electron beams which are produced in the form of ribbonlike beams by transverse electron guns. For attaining this object, the invention essentially consists in mounting a plurality of transverse electron guns in a row in a magnetic field which is formed by a pair of long plates which form or are provided with pole pieces. These electron guns are spaced at relatively short distances from each other for shooting electron beams either into a corresponding number of elongated vaporizer crucibles or into one long vaporizer tray.

The above-mentioned as well as further features and advantages of the present invention will become more clearly apparent from the following detailed description thereof which is to be read with reference to the accompanying diagrammatic drawings in which only the essential features of the invention are illustrated, while the conventional parts of the apparatus are omitted, and in which:

FIGURE 1 shows a plan view of an apparatus according to the invention in which the beam tension or beam velocity in electron-volts and the strength of the magnetic flux are coordinated in such a manner that each electron beam will impinge upon the material in the vaporizer crucible adjacent to the respective electron gun;

FIGURE 2 shows a cross section which is taken along the line aa of FIGURE 1;

FIGURE 3 shows a modification of the invention in which each electron beam impinges upon the material in the vaporizer crucible following the next crucible;

FIGURE 4 shows a view, partly in cross section, of an apparatus with exchangeable pole pieces;

FIGURE 5 shows a preferred embodiment of the invention with inclined magnetic pole plates;

FIGURE 6 shows a partial elevation of an apparatus with arcuate control elements;

FIGURE 7 shows a cross section which is taken along the line b-b of FIGURE 6; while FIGURE 8 shows the application of the invention to a single long vaporizer tray.

Referring to the drawings and first particularly to FIG- URES l and 2, the apparatus according to the invention essentially comprises a rotatable roller 1 which is mounted within the outer housing of a vaporizing chamber, not shown, which may be evacuated and opened in a conventional manner. This roller 1 carries the band or web of material 2 which is to be coated by vapor-deposition and which is conveyed by a mechanism which may also be of a conventional type and is therefore not illustrated. Underneath the roller 1 a series of vaporizer crucibles 4 are located, the longitudinal axes of which extend transverse to the longitudinal axis of roller 1. In order to attain a uniform vapor-coating on web 2 across its entire width the crucibles 4 are preferably spaced from the roller 1 at a distance which is at least equal to the distance between the adjacent crucibles.

Between the adjacent crucibles 4 transverse electron guns 5 are mounted from which electron beams 6 emerge first in the general direction toward roller 1. These ribbon-like beams 6 are then deflected by the magnetic field H in a manner so as to impinge upon the material in the crucible 4 adjacent to the respective gun 5 and thus to heat and vaporize this material.

The magnetic field H is produced by a pair of plates 7 which consist, for example, of soft iron and are magnetized by the coils 8 and the magnet yokes 9. These magnet yokes 9 are connected to the plates 7 by yoke arms 10 which may be provided at different points and of different cross-sectional sizes so as to insure that the magnetic field will be uniform.

The magnetic field and the beam tension or the beam velocity in electron-volts may also be coordinated in the manner as illustrated in FIGURE 3 so that the electron beam 12 of each gun 5 will impinge upon the material in the vaporizer crucible 4 following the next crucible or in a crucible which is still more remote from the respective gun 5.

As indicated in FIGURE 4, it is advisable to provide the plates 7 with removable pole pieces 13 so as to permit them to be easily exchanged in the event that vaporlayers of too great a thickness have been deposited thereon.

For homogenizing the magnetic field H, it is also advisable as illustrated in FIGURE 5, to mount the plates 7 so as to extend at a slight inclination to the axis 14 of the apparatus and in a manner so that at their points of connection to the yoke arms 10 they will be spaced at the greatest distance from the axis 14. In order to make the magnetic field very uniform or to guide each ribbonlike electron beam 6 very accurately, it is also possible, as shown in FIGURES 6 and 7, to mount arcuate control elements 15 on the plates 7.

Instead of providing a series of vaporizer crucibles 4 as shown in FIGURES 1 to 3, it is also possible to provide a single long vaporizer tray 16, as shown in FIG- URE 8. The transverse electron guns are in this case mounted above the crucible 16 and they are preferably protected from a vapor deposition by shields 17 which are preferably heated to such a high temperature that the vapor will not adhere thereto. Of course, it is also possible to protect other parts of the apparatus from vapor deposition, especially the supporting insulators of the electron guns 5 and their current leads.

Although my invention has been illustrated and described with reference to the preferred embodiments thereof, I wish to have it understood that it is in no way limited to the details of such embodiments, but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosed my invention, what I claim 1. An apparatus for coating wide bands of materials by vapor deposition in a vacuum comprising a plurality of elongated transversely disposed electron guns and a like number of transversely disposed elongated crucibles, each of which is adapted to contain a certain material to be vaporized, said electron guns and said crucibles being alternately arranged in spaced relation to each other in a longitudinally extending row, means for producing a magnetic field comprising a pair of magnetic yoke means and a pair of elongated plates forming pole pieces, said plates being disposed in spaced opposed relation to each other one on each side of said longitudinally extending row and extending from end to end of said row, connecting means by which said plates are connected to said yokes, said plates and said connecting means being effective to produce a substantially uniform magnetic field between said plates throughout the length thereof, each of said electron guns being adapted to shoot a ribbon-like electron beam into one of said crucibles to heat and vaporize the material therein, the velocity of said electron beams, and the strength of said magnetic field being co ordinated in such a manner that the electron beam of each gun is deflected so as to be directed into the next succeeding adjacent crucible in said longitudinally extending row of electron guns and crucibles.

2. An apparatus for coating wide bands of material by vapor deposition as defined by claim 1 in which said connecting means comprises a plurality of spaced parallel yoke arms, one of said arms being connected to and between the mid-section of each of said plates and one of said yokes, and other of said arms being connected to and between each of said plates and one of said yokes between the mid-section of each plate and each end thereof, the cross-sectional area of the said other of said arms being less than the cross-sectional area of the said one of said arms.

3. An apparatus for coating wide bands of material by vapor deposition as defined by claim 1 in which said connecting means comprises a pair of yoke arms one of which is connected between the mid-section of each of said plates and one of said yokes; and in which said plates converge between the mid-sections thereof and each of the ends thereof.

4. An apparatus for coating wide bands of material by vapor deposition in a vacuum comprising a plurality of transversely disposed electron guns which are arranged in spaced relation to each other in a longitudinally extending row, means which is disposed in spaced relation to said electron guns and is adapted to contain a certain material to be vaporized, means for producing a magnetic field comprising a pair of magnetic yoke means and a pair of elongated plates forming pole pieces, said plates being disposed in spaced opposed relation to each other one on each side of said longitudinally extending row and extending from end to end of said row, connecting means by which said plates are connected to said yokes, said plates and said connecting means being effective to produce a uniform magnetic field between said plates throughout the length thereof, each of said electron guns being adapted to shoot a ribbon-like electron beam into said container means to heat and vaporize the material therein, the velocity of said electron beams and the strength of said magnetic field being coordinated in such a manner that the electron beam of each gun is deflected so as to be directed into said first mentioned means.

5. An apparatus for coating wide bands of material by vapor deposition in a vacuum comprising a plurality of transversely disposed electron guns which are arranged in spaced relation to each other in a longitudinally extending row, an elongated longitudinally extending tray which is disposed below said longitudinally extending row of electron guns in vertically spaced relation thereto and extends from end to end of said row and is adapted to contain a certain material to be vaporized, means for producing a magnetic field comprising a pair of magnetic yoke means and a pair of elongated plates forming pole pieces, said plates being disposed in spaced relation to each other one on each side of said longitudinally extending row and extending from end to end of said row, connecting means by which said plates are connected to said yokes, said plates and said connecting means being effective to produce a substantially uniform magnetic field between said plates throughout the length thereof, each of said electron guns being adapted to shoot a ribbonlike electron beam into said container means to heat and vaporize the material therein, the velocity of said electron beams and the strength of said magnetic field being coordinated in such a manner that the electron beam of each gun is deflected so as to be directed into said tray.

6. An apparatus for coating wide bands of material by vapor deposition as defined by claim 5 in which said connecting means comprises a plurality of spaced parallel yoke arms, one of said arms being connected to and between the mid-section of each of said plates and one of said yokes, and other of said arms being connected to and between each of said plates and one of said yokes between the mid-section of each plate and each end thereof, the cross-sectional area of the said other of said arms being less than the cross-sectional area of the said one of said arms.

7. An apparatus for coating wide bands of material by vapor deposition as defined by claim 5 in which said connecting means comprises a pair of yoke arms one of which is connected between the mid-section of each of said plates and one of said yokes; and in which said plates converge between the mid-sections thereof and each of the ends thereof.

8. An apparatus for coating wide bands of material by vapor deposition as defined by claim 1 in which the opposed faces of said pair of plates are each provided with a plurality of pairs of spaced concentric control elements by which the electron beams emitted by each of said electron guns is guided into an adjacent crucible.

References Cited by the Examiner UNITED STATES PATENTS 2,932,588 4/1960 Frank.

3,036,549 5/1962 Iwata et al. ll849.l 3,043,728 7/1962 Stautfer 1l8-49 X 3,046,936 7/1962 Simons.

3,170,019 2/1965 Hanks 13-31 3,172,007 3/1965 Hanks et al. 13-31 X 3,183,563 5/1965 Smith 118-49.l

JOSEPH V. TRUHE, Primary Examiner.

Claims

1. AN APPARATUS FOR COATING WIDE BANDS OF MATERIALS BY VAPOR DEPOSITION IN A VACUUM COMPRISING A PLURALITY OF ELONGATED TRANSVERSELY DISPOSED ELECTRON GUNS AND A LIKE NUMBER OF TRANSVERSELY DISPOSED ELONGATED CRUCIBLES, EACH OF WHICH IS ADAPTED TO CONTAIN A CERTAIN MATERIAL TO BE VAPORIZED, SAID ELECTRON GUNS AND SAID CRUCIBLES BEING ALTERNATELY ARRANGED IN SPACED RELATION TO EACH OTHER IN A LONGITUDINALLY EXTENDING ROW, MEANS FOR PRODUCING A MAGNETIC FIELD COMPRISING A PAIR OF MAGNETIC YOKE MEANS AND A PAIR OF ELONGATED PLATES FORMING POLE PIECES, SAID PLATES BEING DISPOSED IN SPACED OPPOSED RELATION TO EACH OTHER ONE ON EACH SIDE OF SAID LONGITUDINALLY EXTENDING ROW AND EXTENDING FROM END TO END OF SAID ROW, CONNECTING MEANS BY WHICH SAID PLATES ARE CONNECTED TO SAID YOKES, SAID PLATES AND SAID CONNECTING MEANS BEING EFFECTIVE TO PRODUCE A SUBSTANTIALLY UNIFORM MAGNETIC FIELD BETWEEN SAID PLATES THROUGHOUT THE LENGTH THEREOF, EACH OF SAID ELECTRON GUNS BEING ADAPTED TO SHOOT A RIBBON-LIKE ELECTRON BEAM INTO ONE OF SAID CRUCIBLES TO HEAT AND VAPORIZE THE MATERIAL THEREIN, THE VELOCITY OF SAID ELECTRON BEAMS, AND THE STRENGTH OF SAID MAGNETIC FIELD BEING COORDINATED IN SUCH A MANNER THAT THE ELECTRON BEAM OF EACH GUN IS DEFLECTED SO AS TO BE DIRECTED INTO THE NEXT SUCCEEDING ADJACENT CRUCIBLE IN SAID LONGITUDINALLY EXTENDING ROW OF ELECTRON GUNS AND CRUCIBLES.