Method for producing a shielding case

Abstract

Method of producing a shielding casing ( 4 ) in which there is provided a sealing and shielding profile section ( 9 ) which fills a gap between first and second adjoining casing portions ( 1, 2 ) and which comprising pasty material is applied under pressure from a coordinate-controlled applicator device ( 5 ) having an applicator needle or nozzle directly on to onto the first casing portion and then sets there elastically adhering thereto in self-supporting relationship, wherein the sealing and shielding profile section is produced by simultaneously applying at least one first material ( 8 a) with material properties adapted for a good sealing action and a second material ( 8 b) with material properties adapted to a good shielding action, from the applicator needle or nozzle ( 6 ) provided with at least a first and a second passage ( 6 a, 6 b), whereby the second material firmly adheres to the first material.

1. A method of producing a shielding casing for mechanically protecting and electromagnetically shielding an electronic functional unit, in which there is provided a sealing and shielding profile section which fills a gap between a  first and second adjoining casing portions and which comprises pasty material applied under pressure from a coordinate-controlled applicator needle or nozzle directly on to  onto the first casing portion which then sets elastically, adhering thereto in self-supporting relationship, comprising: producing the sealing and shielding profile section by simultaneously applying at least a first material which sets elastically, with material properties which are adapted to a good shielding  sealing action, and a second material, which sets elastically,  with material properties which are adapted to a good sealing  shielding action, from the applicator needle or nozzle which is provided with at least a first and a second passage, whereby the second material adheres firmly to the first material and wherein one of the first and second materials forms a base portion and the other of the first and second materials forms a layer that at least partially surrounds the base portion. 
     
     
       2. The method of  claim 1 , wherein the second casing portion is brought into contact with the sealing and shielding profile section after substantially complete hardening of the first and/or second material. 
     
     
       3. The method of  claim 1 , wherein the first material used is a substantially non-conductive plastic material which hardens in air and at ambient temperature and the second material used is a plastic material which is made conductive by means of electrically conducting inclusions, the second plastic material being of the same kind of material as the first material. 
     
     
       4. The method of  claim 3 , wherein particles comprising a metal or an alloy with a high level of electrical conductivity are used as electrically conducting inclusions. 
     
     
       5. The method of  claim 3 , wherein the first material contains a non-conductive filler. 
     
     
       6. The method of  claim 1 , wherein a bonding agent is used when applying the first and/or second material. 
     
     
       7. The method of  claim 1 , wherein the first passage of the applicator needle or nozzle is surrounded at least over a part of its periphery by the second passage. 
     
     
       8. The method of  claim 1 , wherein application of the sealing and shielding profile section is effected by using an applicator needle or nozzle whose first passage is of substantially circular cross-section and is concentrically surrounded at least in portion-wise manner by the second passage, wherein the latter is of a cross-section that is substantially in the form of a segment of a circular ring. 
     
     
       9. The method of  claim 1 , wherein the second material is applied in the profile cross-section with irregular thickness. 
     
     
       10. The method of  claim 9 , wherein the second material is applied on the inside of the casing with a greater thickness than in the part towards a casing portion and/or on the outside of the casing. 
     
     
       11. The method of  claim 3 , wherein the non-conductive plastic material is made of silicone and has thixotropic properties. 
     
     
       12. The method of  claim 4 , wherein the particles are fibres or flakes of silver or silver-bearing alloy. 
     
     
       13. The method of  claim 5 , wherein the non-conductive filler is oxidic or ceramic.