Disk drive head suspension tail with ground pad outside of bonding region

Abstract

A head gimbal assembly for a disk drive includes a flexure tail terminal region having flexure bond pads in electrical communication with the head. Each of the flexure bond pads is aligned with one of a plurality of flexible printed circuit (FPC) bond pads. An anisotropic conductive film is disposed between the FPC and the flexure tail terminal region. The flexure tail terminal region overlaps the anisotropic conductive film in a bonding area. Each of the flexure bond pads is bonded to one of the plurality of FPC bond pads by the anisotropic conductive film in a bonding area. A conductive layer of the flexure tail terminal region includes an exposed conductive ground pad that is disposed outside of the bonding area, and/or disposed outside of an application area of a thermode tool that is pressed against the flexure tail terminal region during the bonding process.

What is claimed is: 
     
         1 . A method of manufacturing a head stack assembly for a disk drive, the method comprising:
 providing an actuator including at least one actuator arm and a flexible printed circuit (FPC) that includes a plurality of electrically conductive FPC bond pads;   attaching at least one head gimbal assembly to the at least one actuator arm, the at least one head gimbal assembly comprising a head for reading and writing data on the disk and a suspension assembly that comprises a load beam and a laminated flexure, the laminated flexure including a structural layer, a conductive layer, and a dielectric layer between the structural layer and the conductive layer, the laminated flexure including a tongue portion that connects to the read head and a flexure tail that extends to the plurality of FPC bond pads;   aligning a terminal region of the flexure tail with the FPC so that it at least partially overlaps the FPC, the flexure tail terminal region including a plurality of flexure bond pads in electrical communication with the head, with each of the plurality of flexure bond pads being aligned with a corresponding one of the plurality of FPC bond pads;   disposing an anisotropic conductive film between the FPC and the flexure tail terminal region; and   pressing a thermode tool against a thermode tool application area of the flexure tail terminal region to bond each of the plurality of flexure bond pads to the corresponding one of the plurality of FPC bond pads by the anisotropic conductive film;   wherein the conductive layer further comprises an exposed conductive ground pad that is disposed outside of the thermode tool application area.   
     
     
         2 . The method of  claim 1  wherein the thermode tool applies heat and increased pressure to the plurality of flexure bond pads in the thermode tool application area. 
     
     
         3 . The method of  claim 1  wherein the total longitudinal span of the flexure tail terminal region is in the range of 3 mm to 8 mm, and a longitudinal span of the thermode tool is in the range of 2 mm to 7 mm. 
     
     
         4 . The method of  claim 2  wherein the flexure tail terminal region includes a bent portion extending approximately normally from a major plane of the flexure tail terminal region, the bent portion being disposed outside the thermode tool application area, wherein the bent portion longitudinally spans the exposed conductive ground pad. 
     
     
         5 . The method of  claim 1  wherein all of the plurality of flexure bond pads are disposed within the thermode tool application area of the flexure tail terminal region, so that all are bonded simultaneously by pressing the thermode tool. 
     
     
         6 . The method of  claim 1  further comprising contacting a test probe with the exposed conductive ground pad to make temporary electrical connection with the exposed conductive ground pad for testing. 
     
     
         7 . The method of  claim 1  wherein disposing the anisotropic conductive film between the FPC and the flexure tail terminal region comprises overlaying a rectangular strip of the anisotropic conductive film on the FPC. 
     
     
         8 . The method of  claim 1  wherein pressing the thermode tool against the thermode tool application area of the flexure tail terminal region does not bond the exposed conductive ground pad to any of the plurality of FPC bond pads.