GB1177081A - Improvements in or relating to Vacuum Coating - Google Patents

Abstract

1,177,081. Apparatus for vacuum coating. BIR-VAC Ltd. Jan.18, 1967 [March 25, 1966], No.13448/66. Heading C7F. Vacuum coating apparatus comprises an electron emitting filament 38 mounted in an annular housing 34 an aperture 41 allowing the electron beam to bombard the source material in crucible 29 mounted on a turn-table 26 so that the crucible position can be displayed vertically in a continuously variable manner, and a conical shield 39 which shields a substrate 40 from direct heat radiation from the filament 38 see Figures 2 and 6. The assembly is mounted in a vacuum chamber and three shafts 7, 8, 9 with outside handle 10 extend through baseplate 1. Fixed to shaft 7 is sprocket wheel 11 connected by chain 12 to sprocket wheel 13 which on turning turns crucible 29 on turn-table 26 about a shaft 21. The shaft 8 is connected via running nut 15 to a pivoted lever 17 which is forked at 19 to engage collar 20 fixed to shaft 21 mounted so as to be rotatable and axially displaceable in plate 5. By turning handle 10 on shaft 8 the crucible 29 is thus displaced vertically. A shutter 33 is fixed to shaft 9 by arm 32 so that the shutter can swing into position above the filament 38 to prevent contamination of substrate (40) at the start of heating. It is swung away when vapour deposition is started. In operation the charged crucible is placed in one of the holes 27 while in position of Figure 3 (not shown). Shaft 7 is turned to bring the hole into the lower position shown in Figure 6, handle 10 is then turned to raise turn-table 26 into the upper position in Figure 6, this position being adjustable and dependent on the temperature required in the crucible. In a further embodiment shown in Figure 7 the crucible is shielded by housing portion 100 from heat radiation during electron bombardment and both the lifting and rotation of the crucible are produced by shaft 8. The end 106 of lever 17 cooperates with a ring of teeth 101 fixed to shaft 21 which has a bearing 102 connected to a ring of teeth 103. A lateral pin 104 fixed to shaft 21 cooperates with teeth 103 and spring 105 urges shaft 21 downwardly. Turning of shaft 8 lifts end 106 which rides up the flank of one of the teeth 101 and turns turn-table 26. A number of crucibles can be brought successively to the bombardment position for each reciprocation of end 106. Both conductive and non-conductive materials may be evaporated.