Method for producing a shielding gasket

Abstract

The invention relates to a method for producing an electromagnetic shielding gasket. The task is accomplished, according to the invention, through a method according to claim 1 as well as an electrical apparatus having a corresponding gasket according to claim 6. Advantageous further developments are described in the dependent claims. Method for producing an electromagnetic shielding gasket by means of a shielding substance that contains a silicone plastic mass, electrically-conducting components, and components that are expandable under the influence of heat, in which method the gasket compound is dispensed onto a housing and/or printed circuit board and/or housing parts, and after and/or during the dispensing is treated with heat, thereby obtaining its desired, predetermined expansion and/or shape.

1 . Method for producing an electromagnetic shielding gasket by means of a shielding substance that contains a silicone plastic mass, electrically-conducting components, and components that are expandable under the influence of heat, in which method the gasket substance is dispensed onto a housing and/or printed circuit board and/or housing parts, and after and/or during the dispensing is treated with heat, thereby obtaining its desired, predetermined expansion and/or shape.  
   
   
       2 . Method according to  claim 1 , wherein the expandable particles, in the non-expanded state, have a diameter that is substantially in the range of 2 to 50 μm, and in the expanded state a diameter that is substantially in the range of approximately 30 to 200 μm.  
   
   
       3 . Method according to  claim 1  wherein the expandable components are micro spheres or micro hollow spheres consisting of a polymer or another plastic, which spheres are electrically nonconductive and, through heat treatment, are enlargeable in size by a factor of approximately 5 to 70 in volume.  
   
   
       4 . Method according to  claim 1 , wherein during the heat treatment the temperature of the shielding substance lies approximately in the range of 50° C. to 140° C.  
   
   
       5 . Method according to  claim 1 , wherein after the dispensing and after the heat treatment the shielding substance is essentially circular in cross section (bead, double bead).  
   
   
       6 . Electrical apparatus having a housing and/or printed circuit board, produced by a method according to  claim 1 .  
   
   
       7 . Electrical apparatus according to  claim 6 , wherein the electrical apparatus is a receiver, a mobile telephone, a control, a regulator, a computer, or the like.  
   
   
       8 . Method according to  claim 6 , wherein means are provided whereby the expansion is guided into a direction and/or shape that is associated with the purpose and/or is appropriate.  
   
   
       9 . Method according to  claim 6 , wherein the expanded shielding substance undergoes locally a different (partial) heat treatment, in order to achieve targeted, different heights and/or widths of the expanded shielding substance and to lower the possible physical deformation forces.