US 4,380,212 A · Arrangement for uniformly coating surfaces of revolution by vapor deposition in a high vacuum

Abstract

Surfaces of revolution to be coated by vapor deposition are placed in centering holes of a rotary dome which is centrally seated on a rotary ring. The rotary ring centered by means of fixedly mounted guide and drive rollers so as to have an evaporative source located as close as possible to the axis of rotation of the dome and at the center of curvature of the dome. The substance, vaporized by heating in a high vacuum space, condenses on the substrates as a thin layer. From the variation of the layer thickness, the outline of a corrective mask is computed for a constant radiant intensity of the vapor in all utilizable directions in the space, while assuming a central, point source of evaporation. A corresponding corrective mask is then secured by means of a support to another rotary ring in close proximity to the surfaces of revolution to be coated, which other ring is centered in the same manner as the first rotary ring, but rotates in the opposite direction about the same axis. Under otherwise equal conditions and in spite of a deviation from ideal conditions, this results in a uniform coating of high precision, that is, in an equal layer thickness at all points of the surfaces of revolution which are equally spaced from the center of the surface.

Claims17

Dependent claims

An apparatus for uniformly coating a number of substrates with surfaces of revolution by vapor deposition in a high-vacuum container by means of at least one evaporative source for producing a vapor stream comprising a structure for supporting all the substrates to be coated which is rotatable about a fixed axis, and at least one corrective mask for intercepting the vapor stream and which also is rotatable about a fixed axis, wherein the apparatus is structured so that:

(a) all substrate axes (A.sub.1, A.sub.2) intersect at a single point (S);
(b) all substrate poles (P.sub.1, P.sub.2) are equidistantly spaced from the point of intersection (S) of the substrate axes;
(c) an axis of rotation (A.sub.0) of the structure supporting the substrates passes through the point of intersection (S) of the substrate axes;
(d) an axis of rotation of the at least one corrective mask coincides with the axis of rotation (A.sub.0) of the structure supporting the substrate, which structure rotates in opposite direction;
(e) the distance between the evaporative source and the point of intersection (S) of the substrate axes corresponds to less than 15% of the distance between the point of intersection (S) of the substrate axes and the substrate poles (P.sub.1, P.sub.2);
(f) the distance between the corrective mask and the substrates corresponds to less than 15% of the distance (R.sub.p) between the point of intersection (S) of the substrate axes and the substrate poles (P.sub.1, P.sub.2);
and
(g) the contour of the at least one corrective mask is determined empirically from the distribution of the vapor radiation in the container space, to the effect that on a spherical surface on which all the substrate poles are located, an even coating is produced.

5 more elements

A device for the vapor deposition coating a plurality of substrates in a high-vacuum space comprising:

an evaporative source for producing a vapor stream of a radiant intensity (I.sub.0);
a substrate support member having a spherical surface for carrying a plurality of substrates and holding the substrates in a position to face said evaporative source, said support member being rotatably mounted about a support member axis which extends through a single selected point (S);
at least one corrective mask shaped to block at least some of the vapor stream and rotatably mounted about said support member axis, said mask having a contour selected to cause even coating of the vapor stream on the spherical surface of said support member during rotation of said support member and said mask;
drive means connected to said support member and mask for driving said support member and mask in opposite directions;
each of the substrates carried on said support member having a substrate axis and substrate pole, with the substrate axis of each substrate intersecting the single selected point and the substrate poles being equidistant from the single selected point;
the distance between said evaporative source and said single selected point being less than 15% of the distance between said single selected point and each of the substrate poles;
and
the distance between said at least one corrective mask and each substrate being less than 15% of the distance between said single selected point and the substrate poles.

5 more elements

Dependencies are inferred from the claim text.

Arrangement for uniformly coating surfaces of revolution by vapor deposition in a high vacuum

Life of this patent

Arrangement for uniformly coating surfaces of revolution by vapor deposition in a high vacuum

Life of this patent

Abstract

Claims17