Disc drives having flexible circuits with liquid crystal polymer dielectric

Abstract

The present invention pertains to a suspension assembly having a load beam and a flexible circuit. The flexible circuit is positioned on the load beam and includes an electrically conductive element and a dielectric liquid crystal substrate laminated to the conductive element.

1 . A suspension assembly comprising: 
 a load beam; and    a flexible circuit positioned on the load beam and comprising an electrically conductive element and a dielectric liquid crystal substrate laminated to the conductive element.    
     
     
         2 . The suspension assembly of  claim 1  wherein the conductive element comprises copper.  
     
     
         3 . The suspension assembly of  claim 1  wherein the dielectric liquid crystal substrate has a thickness less than about 0.001 inches.  
     
     
         4 . The suspension assembly of  claim 1  wherein the dielectric liquid crystal substrate has a thickness from about 0.0001 inches to about 0.0005 inches.  
     
     
         5 . The suspension assembly of  claim 1  wherein the dielectric liquid crystal substrate comprises a polyester.  
     
     
         6 . The suspension assembly of  claim 1  wherein the dielectric liquid crystal substrate has a dielectric constant from about 2.6 to about 3.0.  
     
     
         7 . The suspension assembly of  claim 1  wherein the dielectric liquid crystal substrate has a coefficient of thermal expansion from about 15 ppm/° C. to about 19 ppm/° C.  
     
     
         8 . The suspension assembly of  claim 1  wherein the dielectric liquid crystal substrate has a coefficient of humidity expansion of less than about 4 ppm/% relative humidity.  
     
     
         9 . The suspension assembly of  claim 1  wherein the dielectric liquid crystal substrate has an elastic modulus from about 900 kpsi to about 1300 kpsi.  
     
     
         10 . The suspension assembly of  claim 1  further comprising a cover coating forming a protective coating over at least a portion of the conductive element.  
     
     
         11 . The suspension assembly of  claim 1  wherein the liquid crystal substrate comprises a thermoplastic.  
     
     
         12 . The suspension assembly of  claim 1  wherein the data storage disc comprises a magnetic disc.  
     
     
         13 . The suspension assembly of  claim 1  and further comprising a transducer head supported on the load beam, the flexible circuit being electrically connected to the transducer head.  
     
     
         14 . A device for supporting a transducing element, the device comprising: 
 a flexible circuit electrically coupled to the transducing element, the flexible circuit comprising: 
 an electrically conductive element; and  
 a dielectric liquid crystal substrate laminated to the conductive element.  
   
     
     
         15 . The device of  claim 14 , wherein the dielectric liquid crystal substrate comprises a liquid crystal polymer.  
     
     
         16 . The device of  claim 14  further comprising a cover coating that forms a protective coating over at least a portion of the electrically conductive element.  
     
     
         17 . The device of  claim 16 , wherein the cover coating comprises a liquid crystal polymer.  
     
     
         18 . The device of  claim 16 , wherein the cover coating has a thickness that is less than about 0.0001 inches.  
     
     
         19 . The device of  claim 18 , wherein the cover coating has a thickness that is between about 0.0002 inches and about 0.0005 inches.