Copper residual stress relaxation reduction means for hard disk drive slider gimbals

Abstract

Disclosed are various techniques for reduction of the magnitude of the residual stress in the HDD gimbal circuits, or more specifically, the residual plastic strain. Various trace structures of the gimbal circuits as well as stress suppressors are utilized to achieve the reduction of the residual stress in the circuit.

1 . A hard drive (HDD) gimbal trace circuit characterized in reduced magnitude of the residual stress or residual plastic strain, the trace circuit comprising:
 a plurality of traces, the plurality of traces forming a trace structure; and   a strut configured to support a transducer,   wherein the trace structure has, in a proximity of a high strain region, a characteristic shape selected from a group consisting of an outward circle shape, a double outward circle shape, a waving and narrowing shape, an outward jog, a partial outward jog with a slot, a dual jog, and an inner trace overlap.   
   
   
       2 . The hard drive (HDD) gimbal trace circuit of  claim 1 , further comprising at least one stress suppressor, the at least one stress suppressor comprising at least one island structure disposed under the plurality of traces in the proximity of the high strain region, the at least one stress suppressor comprising stainless steel. 
   
   
       3 . The hard drive (HDD) gimbal trace circuit of  claim 2 , wherein the at least one stress suppressor has a circular shape. 
   
   
       4 . The hard drive (HDD) gimbal trace circuit of  claim 2 , wherein the at least one stress suppressor has a rectangular shape. 
   
   
       5 . The hard drive (HDD) gimbal trace circuit of  claim 2 , wherein the stress suppressor comprises at least two island structures. 
   
   
       6 . The hard drive (HDD) gimbal trace circuit of  claim 2 , wherein the stress suppressor comprises at least five island structures. 
   
   
       7 . The hard drive (HDD) gimbal trace circuit of  claim 1 , further comprising a coverlayer window. 
   
   
       8 . The hard drive (HDD) gimbal trace circuit of  claim 1 , further comprising at least one stress suppressor, the at least one stress suppressor comprising at least one protrusion of the strut disposed under the plurality of traces in the proximity of the high strain region. 
   
   
       9 . A hard drive (HDD) gimbal trace circuit characterized in reduced magnitude of the residual stress or residual plastic strain, the trace circuit comprising:
 a plurality of traces, the plurality of traces forming a trace structure; and   a strut configured to support a transducer;   wherein the traces in the trace structure are either narrowed or widened in a proximity of a high strain region.   
   
   
       10 . The hard drive (HDD) gimbal trace circuit of  claim 9 , wherein the trace structure has, in the proximity of the high strain region, a characteristic shape selected from a group consisting of an outward circle shape, a double outward circle shape, a waving and narrowing shape, an outward jog, a partial outward jog with a slot, a dual jog, and an inner trace overlap. 
   
   
       11 . A hard drive (HDD) gimbal trace circuit characterized in reduced magnitude of the residual stress or residual plastic strain, the trace circuit comprising:
 a plurality of traces, the plurality of traces forming a trace structure;   a strut configured to support a transducer; and   at least one stress suppressor, wherein the at least one stress suppressor is either a protrusion of the strut or an island structure, the stress suppressor being disposed under the plurality of traces in a proximity of a high strain region.   
   
   
       12 . The hard drive (HDD) gimbal trace circuit of  claim 11 , further comprising a second stress suppressor, wherein the second stress suppressor is a protrusion of the strut and wherein the second stress suppressor being disposed under the plurality of traces. 
   
   
       13 . The hard drive (HDD) gimbal trace circuit of  claim 11 , wherein the at least one stress suppressor is the island structure having a circular shape. 
   
   
       14 . The hard drive (HDD) gimbal trace circuit of  claim 11 , wherein the at least one stress suppressor is the island structure having a rectangular shape. 
   
   
       15 . The hard drive (HDD) gimbal trace circuit of  claim 11 , wherein if the stress suppressor is the island structure disposed under the plurality of traces, the stress suppressor further comprising at least a second island structure. 
   
   
       16 . The hard drive (HDD) gimbal trace circuit of  claim 11 , wherein if the stress suppressor is an island structure disposed under the plurality of traces, the stress suppressor further comprising at least four additional island structures. 
   
   
       17 . The hard drive (HDD) gimbal trace circuit of  claim 11 , further comprising a coverlayer window. 
   
   
       18 . The hard drive (HDD) gimbal trace circuit of  claim 11 , wherein the trace structure in the proximity of the high strain region has a characteristic shape selected from a group consisting of an outward circle shape, a double outward circle shape, a waving and narrowing shape, an outward jog, a partial outward jog with a slot, a dual jog, and an inner trace overlap. 
   
   
       19 . The hard drive (HDD) gimbal trace circuit of  claim 11 , wherein the traces in the trace structure are either narrowed or widened in the proximity of the high strain region. 
   
   
       20 . The hard drive (HDD) gimbal trace circuit of  claim 11 , wherein the at least one stress suppressor is the island structure comprising stainless steel.