Patent Application
20100154905
The invention relates to an arrangement according to the preamble of patent claim 1.
When coating substrates with certain substances, the substances are converted into the gaseous state and subsequently conducted to the substrate. The substances can, for example, be heated in a crucible and made to vaporize. The vapor is subsequently supplied, for example via guide elements, to the substrate.
EP 1 672 715 A1 discloses an arrangement for coating a substrate, which arrangement comprises a vaporizer source, a vapor guide device and a mechanical vapor block in the vapor guide device. The vapor block is herein realized as a valve comprised of quartz. This valve can be opened or closed.
An arrangement for vacuum coating is furthermore known, which comprises a crucible in which organic material is heated and vaporized (WO 2006/061517 A1). Between this crucible and the coating chamber is disposed a valve with which the vapor is controllable. The valve is herein realized as a horizontally movable gate valve.
In an OLED vaporizer source a valve is provided in order to stop the material stream when the vaporizer source is not being operated. Since the vaporized organic material is chemically reactive, those parts which come into contact with the organic material, are produced of quartz, which enters only with difficulty into chemical reactions. Said parts are heated to temperatures which exclude condensation of the vaporized organic material. However, at these temperatures the conventional elastic seals are destroyed. Consequently, it is not possible to close the piston of a valve securely.
In the case of conventional valves, which could only assume the states “open” or “closed”, the sealing did not represent a major problem. The piston was simply inserted into an opening of the vaporizer source to close it and pulled out for opening it. Yet to be able to regulate the vaporizer rate better, it is necessary to open or close continuously the opening of the vaporizer source by moving the piston.
However, hereby vapor flows nearly continuously out of the vaporizer source and about the piston, since during normal operation the end positions of the piston are practically never reached. This leads to an undesirable contamination of the vaporizer source and its surroundings. Moreover, a portion of the expensive organic material is lost.
The invention therefore addresses the problem of preventing or reducing the contamination of the vaporizer source and its surroundings even if the vaporizer source is continuously opened and closed.
This problem is solved according to the features of patent claim 1.
The invention consequently relates to an arrangement for the regulation of a gas stream with a dosing pipe for gas as well as a conduit pipe disposed thereon. The dosing pipe can be closed with a tappet located on a movable rod.
The advantage attained with the invention comprises that the gas stream directed counter to the vaporized material suppresses the material flow on the inside of the valve. While the gas stream flowing also about the outside of the valve is not necessarily desirable, it can, however, be accepted.
An embodiment example of the invention is shown in the drawing and will be explained further detail in the following. In the drawing depict:
In principle, to the conduit pipe 10 several vaporizer crucibles can also be connected simultaneously. However, in this case it is necessary that each of these vaporizer crucibles is connected to a regulating valve comprised of a drive and a tappet connected via a rod with the drive. As is also the case in the vaporizer crucible 11, each of these vaporizer crucibles comprises a gate valve 13. In these vaporizer crucibles can be disposed different or like materials to be vaporized. Since these vaporizer crucibles also include heating devices independent of one another, the vaporizer crucibles can alternately be connected to the vacuum chamber and the material disposed in them be vaporized. It is herein not necessary to interrupt the coating process. Since each vaporizer crucible comprises a gate valve, the vaporizer crucibles can therewith be isolated off from the vacuum chamber independently of one another. Replenishing the vaporizer crucibles with material, thus proves to be simple. Via the particular regulating valve, materials can simultaneously be vaporized from one or several vaporizer crucibles. Therewith several vaporizer crucibles can also determine the vaporization rate simultaneously. By slowly opening a regulating valve of a first vaporizer crucible and simultaneously slowly closing a regulating valve of a second vaporizer crucible, the vaporization can be switched over to another vaporizer crucible without interruption of the production.
An arrow 52 indicates the direction of flow of a vaporized organic material which had been vaporized in a crucible not shown in
Holes 54, 55 are connected via a common duct with a gas supply, for example a gas tank, which contains the inert gas. This gas can be, for example, argon. In order to be able to interrupt or regulate the gas supply, the duct, which connects the gas supply with the holes 54, 55, includes valves. However, for the sake of clarity the duct, the gas supply as well as the valves are not shown in
The pressure of the inert gas conducted in the direction of arrow 56 into the conduit pipe 10 is preferably higher or at least as high as the pressure of the vaporized material which is conducted into the conduit pipe 10. Therewith the quantity of vaporizing material, which can penetrate outwardly through the gap between tube 30 and rod 18, is markedly reduced.
In tube 30 are preferably provided two holes 41, 42 through which the inert gas flows into the lower interspace between rod 18 and tube 30. However, more than two holes 41, 42, for example three or four holes, can also be provided. It is further possible to provide an annular channel instead of several holes. In this annular channel the gas can already become uniformly distributed before it reaches the conduit pipe 10. In the conduit pipe 10 a mixture of inert gas and material to be vaporized is now transported in the direction of arrow 53. By controlling the drive 19, and therewith the position of tappet 17, the quantity of vaporized material can be set. The drive 19 cannot be seen in
Evident are also the two holes 54, 55 which are connected via a common duct with a gas supply for an inert gas. This gas supply, however, is not shown in
Those skilled in the art can readily recognize that numerous variations and substitutions may be made in the invention, its use and its configuration to achieve substantially the same results as achieved by the embodiments described herein. Accordingly, there is no intention to limit the invention to the disclosed exemplary forms. Many variations, modifications and alternative constructions fall within the scope and spirit of the disclosed invention as expressed in the claims.
