Patent ID: 8435352

Claim:
Apparatus for coating a substrate using physical vapour deposition, comprising: a vacuum chamber wherein a coil is placed for keeping an amount of conductive material in levitation and for heating and evaporating that material, using a varying electric current in the coil; a container made of an electrically non-conductive material, the container comprising a first portion placed in the coil to isolate the coil from the levitated material, the container comprising a second portion, having one or more openings for guiding evaporated conductive material to the substrate to be coated; and wherein the first portion is vertical and the second portion is horizontal and the first portion has an open top end in communication with an interior of the second portion; at least one heating means disposed at the second portion of the container to prevent condensation of vaporized conductive material, wherein the second portion of the container has the form of a box-shaped protuberance, wherein the protuberance is at least as wide as the substrate to be coated, wherein the box shaped protuberance has a top wall, a bottom wall, a front wall and a rear wall and opposed end walls, wherein the heating means comprise resistive wire heating elements made from a conductive material, wherein the second portion of the container has a box portion, wherein a tube is inserted completely within the box portion and the at least one heating means comprises one or more electrical coils or wires placed between the tube and the box portion, wherein the tube and box portion are concentric and parallel, wherein the tube extends longitudinally from the box first end wall to the box second end wall, wherein the tube lines the inner walls of the box portion, wherein the one or more openings for guiding evaporated conductive material to the substrate to be coated pass through the box portion upper walls and the tube, wherein the at least one heating means comprising one or more electrical coils or wires placed between the tube and the box portion are immobilized by contact with the tube and inner wall of the box portion, and wherein the tube has a circular inner wall and a circular outer wall, the tube being a cylinder having an upper longitudinal semi-cylinder and a lower longitudinal semi-cylinder which meet at an equator, wherein in a cross-sectional plane, transverse to the longitudinal axis of the tube, a first transverse arc along the outer wall of the upper semi-cylinder from a said opening to a first portion of wire passing within the box-shaped protuberance along the upper semi-cylinder is shorter than a second transverse arc along the outer wall of the upper semi-cylinder from said opening to the equator.