Methods of manufacturing EMI shields

Abstract

An electromagnetic interference shield for use around access panels and doors in electronic equipment enclosures includes a base and profile manufactured from an electrically nonconductive solid material such as a thermoplastic resin polymer. An electrically conductive layer of a metallized fabric is bonded to the profile to provide effective shielding and grounding functions. The underlying polymer provides elastic compliancy and resiliency to the shield. The shield may be divided into flexible fingers which can be rectangular or nonlinear shaped. The nonlinear shaped flexible fingers form nonlinear shaped slits between the fingers which provides improved EMI shielding by reducing the amount of EMI transmission that can pass through the shield. The electromagnetic interference shield may also be made from an electrically conductive material.

What is claimed is:  
     
         1 . A method of manufacturing a shield for shielding electromagnetic interference from passing through a seam between a first electrically conductive body and a second electrically conductive body, the method comprising the steps of: 
 forming a base and a profile of a solid material in a predetermined configuration; and    dividing the profile into a plurality of generally independently flexible fingers forming nonlinear slits therebetween.    
     
     
         2 . A method according to  claim 1  wherein the solid material is electrically conductive.  
     
     
         3 . A method according to  claim 2  wherein the solid material comprises a copper beryllium alloy.  
     
     
         4 . A method according to  claim 1  wherein: 
 the solid material is electrically nonconductive; and  
 the method further comprises the step of disposing an electrically conductive layer on the profile.  
 
     
     
         5 . A method according to  claim 4  wherein the forming step is accomplished by extrusion.  
     
     
         6 . A method according to  claim 5  wherein the forming step and the disposing step are accomplished by in-line crosshead extrusion.  
     
     
         7 . A method according to  claim 4  wherein the electrically conductive layer comprises a metallized fabric bonded to the profile.  
     
     
         8 . A method according to  claim 1  wherein the formed nonlinear slits are selected from the group consisting of arcuate slits, interdigitated slits, chevron-shaped slits, and combinations thereof.  
     
     
         9 . A method of manufacturing a shield for shielding electromagnetic interference from passing through a seam between a first electrically conductive body and a second electrically conductive body, the method comprising the steps of: 
 disposing an electrically conductive layer on an electrically nonconductive solid sheet material;    forming the sheet into a base and a profile of a predetermined configuration; and    dividing the profile into a plurality of generally independently flexible fingers forming nonlinear slits therebetween.    
     
     
         10 . A method according to  claim 9  wherein the forming step is accomplished by thermoforming.  
     
     
         11 . A method according to  claim 9  wherein the electrically conductive layer comprises a metallized fabric.  
     
     
         12 . A method according to  claim 9  wherein the formed nonlinear slits are selected from the group consisting of arcuate slits, interdigitated slits, chevron-shaped slits, and combinations thereof.  
     
     
         13 . A shield for shielding electromagnetic interference from passing through a seam between a first electrically conductive body and a second electrically conductive body, the shield comprising: 
 a base for securing the shield to the first body; and    a plurality of generally independently flexible fingers attached to the base for contacting the second body, wherein the plurality of fingers form nonlinear slits therebetween.    
     
     
         14 . A shield according to  claim 13  wherein the fingers are electrically conductive.  
     
     
         15 . A shield according to  claim 14  wherein the fingers comprise a copper beryllium alloy.  
     
     
         16 . A shield according to  claim 13  wherein the base and fingers are formed integrally.  
     
     
         17 . A shield according to  claim 13  wherein: 
 the fingers are electrically nonconductive; and  
 the shield further comprises an electrically conductive layer disposed on the fingers.  
 
     
     
         18 . A shield according to  claim 17  wherein the electrically conductive layer comprises a metallized fabric bonded to the fingers.  
     
     
         19 . A shield according to  claim 13  wherein the fingers are attached to the base by a hinge.  
     
     
         20 . A shield according to  claim 13  further comprising an adhesive strip attached to the base.  
     
     
         21 . A shield according to  claim 13  wherein the base includes a return.  
     
     
         22 . A shield according to  claim 21  wherein the return includes barbing.  
     
     
         23 . A shield according to  claim 13  wherein the formed nonlinear slits are selected from the group consisting of arcuate slits, interdigitated slits, chevron-shaped slits, and combinations thereof.  
     
     
         24 . A method of manufacturing a shield for shielding electromagnetic interference from passing through a seam between a first electrically conductive body and a second electrically conductive body comprising the steps of: 
 forming a base and a profile of an electrically nonconductive solid material in a predetermined configuration; and    disposing an electrically conductive layer comprising a metallized fabric on the profile.    
     
     
         25 . A method according to  claim 24  wherein the forming step is accomplished by extrusion.  
     
     
         26 . A method according to  claim 24  wherein the forming step and the disposing step are accomplished by in-line crosshead extrusion.  
     
     
         27 . A method according to  claim 24  wherein the metallized fabric is bonded to the profile.  
     
     
         28 . A method according to  claim 24  further comprising the step of dividing the profile into a plurality of independently flexible fingers.  
     
     
         29 . A method of manufacturing a shield for shielding electromagnetic interference from passing through a seam between a first electrically conductive body and a second electrically conductive body comprising the steps of: 
 disposing an electrically conductive layer comprising a metallized fabric on an electrically nonconductive solid sheet material; and    forming the sheet into a base and a profile of a predetermined configuration.    
     
     
         30 . A method according to  claim 29  wherein the forming step is accomplished by thermoforming.  
     
     
         31 . A method according to  claim 29  wherein the metallized fabric is bonded to the sheet material.  
     
     
         32 . A method according to  claim 29  further comprising the step of dividing the profile into a plurality of independently flexible fingers.  
     
     
         33 . A shield for shielding electromagnetic interference from passing through a seam between a first electrically conductive body and a second electrically conductive body, the shield comprising: 
 a base for securing the shield to the first body;    a profile of an electrically nonconductive solid material attached to the base for contacting the second body; and    an electrically conductive layer comprising a metallized fabric disposed on the profile.    
     
     
         34 . A shield according to  claim 33  wherein the base and the profile are formed integrally.  
     
     
         35 . A shield according to  claim 33  wherein the metallized fabric is bonded to the profile.  
     
     
         36 . A shield according to  claim 33  wherein the profile comprises a plurality of independently flexible fingers.  
     
     
         37 . A shield according to  claim 33  wherein the profile is attached to the base by a hinge.  
     
     
         38 . A shield according to  claim 33  further comprising an adhesive strip attached to the base.  
     
     
         39 . A shield according to  claim 33  wherein the base includes a return.  
     
     
         40 . A shield according to  claim 39  wherein the return includes barbing.