Covering assembly for crucible used for evaporation of raw materials

Abstract

The present invention provides an assembly comprising two plates or covers, one of which being an outermost plate or cover, and both, at least in part having a perforation pattern over a surface area covering an open side of a crucible having a bottom and surrounding side walls containing raw materials, wherein said outermost cover is mounted at a distance farther from the said crucible than said cover covering said open side of a crucible, and wherein both covers are mounted versus each other, so that, when viewed through an axis in a direction perpendicular to the bottom of the crucible from a distance to said outermost cover of at least 10 times the distance between said two plates or covers, its contents cannot be observed as their perforations and the crucible are never forming one line, perpendicular to the plane formed by said bottom.

1 . An assembly comprising two plates or covers, one of which being an outermost plate or cover, and both, at least in part having a perforation pattern over a surface area covering an open side of a crucible having a bottom and surrounding side walls containing raw materials, wherein said outermost cover is mounted at a distance farther from the said crucible than said cover covering said open side of a crucible, and wherein both covers are mounted versus each other, so that, when viewed through an axis in a direction perpendicular to the bottom of the crucible from a distance to said outermost cover of at least 10 times the distance between said two plates or covers, its contents cannot be observed.  
   
   
       2 . An assembly according to  claim 1 , wherein both covers are mounted versus each other, so that, when viewed in a direction under a restricted viewing angle around each axis perpendicular to the bottom of the crucible, from a distance to said outermost cover of at least 10 times the distance between said two plates or covers, its contents cannot be observed.  
   
   
       3 . Assembly according to  claim 2 , wherein said viewing angle is within a range from 5° up to 30°.  
   
   
       4 . Assembly according to  claim 1 , wherein said at least two plates or covers are mounted parallel.  
   
   
       5 . Assembly according to  claim 2 , wherein said at least two plates or covers are mounted parallel.  
   
   
       6 . Assembly according to  claim 3 , wherein said at least two plates or covers are mounted parallel.  
   
   
       7 . Assembly according to  claim 1 , wherein perforations in plates or covers have equivalent circular diameters in the range of 1 mm up to 5 mm, and an average a distance between centers of the said holes is in the range from 2 mm up to 10 mm.  
   
   
       8 . Assembly according to  claim 2 , wherein perforations in plates or covers have equivalent circular diameters in the range of 1 mm up to 5 mm, and an average a distance between centers of the said holes is in the range from 2 mm up to 10 mm.  
   
   
       9 . Assembly according to  claim 3 , wherein perforations in plates or covers have equivalent circular diameters in the range of 1 mm up to 5 mm, and an average a distance between centers of the said holes is in the range from 2 mm up to 10 mm.  
   
   
       10 . Assembly according to  claim 4 , wherein perforations in plates or covers have equivalent circular diameters in the range of 1 mm up to 5 mm, and an average a distance between centers of the said holes is in the range from 2 mm up to 10 mm.  
   
   
       11 . Assembly according to  claim 5 , wherein perforations in plates or covers have equivalent circular diameters in the range of 1 mm up to 5 mm, and an average a distance between centers of the said holes is in the range from 2 mm up to 10 mm.  
   
   
       12 . Assembly according to  claim 6 , wherein perforations in plates or covers have equivalent circular diameters in the range of 1 mm up to 5 mm, and an average a distance between centers of the said holes is in the range from 2 mm up to 10 mm.  
   
   
       13 . Assembly according to  claim 1 , wherein shortest distances between plates or covers are in the range of from 1 mm up to 20 mm.  
   
   
       14 . Assembly according to  claim 2 , wherein shortest distances between plates or covers are in the range of from 1 mm up to 20 mm.  
   
   
       15 . Assembly according to  claim 3 , wherein shortest distances between plates or covers are in the range of from 1 mm up to 20 mm.  
   
   
       16 . Assembly according to  claim 4 , wherein shortest distances between plates or covers are in the range of from 1 mm up to 20 mm.  
   
   
       17 . Assembly according to  claim 5 , wherein shortest distances between plates or covers are in the range of from 1 mm up to 20 mm.  
   
   
       18 . Assembly according to  claim 6 , wherein shortest distances between plates or covers are in the range of from 1 mm up to 20 mm.  
   
   
       19 . Assembly according to  claim 7 , wherein shortest distances between plates or covers are in the range of from 1 mm up to 20 mm.  
   
   
       20 . Assembly according to  claim 8 , wherein shortest distances between plates or covers are in the range of from 1 mm up to 20 mm.  
   
   
       21 . Assembly according to  claim 9 , wherein shortest distances between plates or covers are in the range of from 1 mm up to 20 mm.  
   
   
       22 . Assembly according to  claim 10 , wherein shortest distances between plates or covers are in the range of from 1 mm up to 20 mm.  
   
   
       23 . Assembly according to  claim 11 , wherein shortest distances between plates or covers are in the range of from 1 mm up to 20 mm.  
   
   
       24 . Assembly according to  claim 12 , wherein shortest distances between plates or covers are in the range of from 1 mm up to 20 mm.  
   
   
       25 . Assembly according to  claim 1 , wherein shortest distances between plates or covers are in the range of from 5 mm up to 10 mm.  
   
   
       26 . Assembly according to  claim 2 , wherein shortest distances between plates or covers are in the range of from 5 mm up to 10 mm.  
   
   
       27 . Assembly according to  claim 3 , wherein shortest distances between plates or covers are in the range of from 5 mm up to 10 mm.  
   
   
       28 . Assembly according to  claim 4 , wherein shortest distances between plates or covers are in the range of from 5 mm up to 10 mm.  
   
   
       29 . Assembly according to  claim 5 , wherein shortest distances between plates or covers are in the range of from 5 mm up to 10 mm.  
   
   
       30 . Assembly according to  claim 6 , wherein shortest distances between plates or covers are in the range of from 5 mm up to 10 mm.  
   
   
       31 . Assembly according to  claim 7 , wherein shortest distances between plates or covers are in the range of from 5 mm up to 10 mm.  
   
   
       32 . Assembly according to  claim 8 , wherein shortest distances between plates or covers are in the range of from 5 mm up to 10 mm.  
   
   
       33 . Assembly according to  claim 9 , wherein shortest distances between plates or covers are in the range of from 5 mm up to 10 mm.  
   
   
       34 . Assembly according to  claim 10 , wherein shortest distances between plates or covers are in the range of from 5 mm up to 10 mm.  
   
   
       35 . Assembly according to  claim 11 , wherein shortest distances between plates or covers are in the range of from 5 mm up to 10 mm.  
   
   
       36 . Assembly according to  claim 12 , wherein shortest distances between plates or covers are in the range of from 5 mm up to 10 mm.  
   
   
       37 . Assembly according to  claim 1 , wherein said perforations are identical for both of said two plates.  
   
   
       38 . Assembly according to  claim 2 , wherein said perforations are identical for both of said two plates.  
   
   
       39 . Assembly according to  claim 3 , wherein said perforations are identical for both of said two plates.  
   
   
       40 . Assembly according to  claim 4 , wherein said perforations are identical for both of said two plates.  
   
   
       41 . Assembly according to  claim 5 , wherein said perforations are identical for both of said two plates.  
   
   
       42 . Assembly according to  claim 6 , wherein said perforations are identical for both of said two plates.  
   
   
       43 . Assembly according to  claim 7 , wherein said perforations are identical for both of said two plates.  
   
   
       44 . Assembly according to  claim 8 , wherein said perforations are identical for both of said two plates.  
   
   
       45 . Assembly according to  claim 9 , wherein said perforations are identical for both of said two plates.  
   
   
       46 . Assembly according to  claim 10 , wherein said perforations are identical for both of said two plates.  
   
   
       47 . Assembly according to  claim 11 , wherein said perforations are identical for both of said two plates.  
   
   
       48 . Assembly according to  claim 12 , wherein said perforations are identical for both of said two plates.  
   
   
       49 . Assembly according to  claim 1 , wherein said perforations are differing for both of the two plates, in that the plate farther from the crucible has smaller perforations.  
   
   
       50 . Assembly according to  claim 2 , wherein said perforations are differing for both of the two plates, in that the plate farther from the crucible has smaller perforations.  
   
   
       51 . Assembly according to  claim 3 , wherein said perforations are differing for both of the two plates, in that the plate farther from the crucible has smaller perforations.  
   
   
       52 . Assembly according to  claim 4 , wherein said perforations are differing for both of the two plates, in that the plate farther from the crucible has smaller perforations.  
   
   
       53 . Assembly according to  claim 5 , wherein said perforations are differing for both of the two plates, in that the plate farther from the crucible has smaller perforations.  
   
   
       54 . Assembly according to  claim 6 , wherein said perforations are differing for both of the two plates, in that the plate farther from the crucible has smaller perforations.  
   
   
       55 . Assembly according to  claim 7 , wherein said perforations are differing for both of the two plates, in that the plate farther from the crucible has smaller perforations.  
   
   
       56 . Assembly according to  claim 8 , wherein said perforations are differing for both of the two plates, in that the plate farther from the crucible has smaller perforations.  
   
   
       57 . Assembly according to  claim 9 , wherein said perforations are differing for both of the two plates, in that the plate farther from the crucible has smaller perforations.  
   
   
       58 . Assembly according to  claim 10 , wherein said perforations are differing for both of the two plates, in that the plate farther from the crucible has smaller perforations.  
   
   
       59 . Assembly according to  claim 11 , wherein said perforations are differing for both of the two plates, in that the plate farther from the crucible has smaller perforations.  
   
   
       60 . Assembly according to  claim 12 , wherein said perforations are differing for both of the two plates, in that the plate farther from the crucible has smaller perforations.  
   
   
       61 . Assembly according to  claim 1 , further provided with a non-perforated cover as a closing cover.  
   
   
       62 . Assembly according to  claim 2 , further provided with a non-perforated cover as a closing cover.  
   
   
       63 . Assembly according to  claim 3 , further provided with a non-perforated cover as a closing cover.  
   
   
       64 . Assembly according to  claim 4 , further provided with a non-perforated cover as a closing cover.  
   
   
       65 . Assembly according to  claim 5 , further provided with a non-perforated cover as a closing cover.  
   
   
       66 . Assembly according to  claim 6 , further provided with a non-perforated cover as a closing cover.  
   
   
       67 . Assembly according to  claim 61 , wherein said two covers, said non-perforated closing cover and said crucible are made from same or differing refractory materials, and wherein said refractory materials are metal or metal alloys selected from the group consisting of tantalum (Ta), molybdene(Mo), niobium(Nb), tungsten (W) and heat-resistant stainless steel.  
   
   
       68 . Assembly according to  claim 62 , wherein said two covers, said non-perforated closing cover and said crucible are made from same or differing refractory materials, and wherein said refractory materials are metal or metal alloys selected from the group consisting of tantalum (Ta), molybdene(Mo), niobium(Nb), tungsten (W) and heat-resistant stainless steel.  
   
   
       69 . Assembly according to  claim 63 , wherein said two covers, said non-perforated closing cover and said crucible are made from same or differing refractory materials, and wherein said refractory materials are metal or metal alloys selected from the group consisting of tantalum (Ta), molybdene(Mo), niobium(Nb), tungsten (W) and heat-resistant stainless steel.  
   
   
       70 . Assembly according to  claim 64 , wherein said two covers, said non-perforated closing cover and said crucible are made from same or differing refractory materials, and wherein said refractory materials are metal or metal alloys selected from the group consisting of tantalum (Ta), molybdene(Mo), niobium(Nb), tungsten (W) and heat-resistant stainless steel.  
   
   
       71 . Assembly according to  claim 65 , wherein said two covers, said non-perforated closing cover and said crucible are made from same or differing refractory materials, and wherein said refractory materials are metal or metal alloys selected from the group consisting of tantalum (Ta), molybdene(Mo), niobium(Nb), tungsten (W) and heat-resistant stainless steel.  
   
   
       72 . Assembly according to  claim 66 , wherein said two covers, said non-perforated closing cover and said crucible are made from same or differing refractory materials, and wherein said refractory materials are metal or metal alloys selected from the group consisting of tantalum (Ta), molybdene(Mo), niobium(Nb), tungsten (W) and heat-resistant stainless steel.▪