Integrated lead suspension with multiple trace configurations

[0001] The invention is an integrated lead or wireless head suspension flexure of the type used in disk drive data storage systems.

[0002] Integrated lead or wireless suspensions and flexures of the type used to support read/write heads in disk drive data storage systems are known and disclosed, for example, in Japanese patent publication JP 10003632 and the following U.S. patents.

[0003]

	Inventor	U. S. Pat. No.
	Klaassen	5,608,591
	Akin, Jr. et al.	5,796,552
	Simmons et al.	5,862,010
	Matz	5,924,187
	Coon et al.	6,424,500
	Putnam	6,728,057
	Coon et al.	6,900,967
	Kulangara et al.	6,975,488
	Someya et al.	7,092,215
	Yoshimi et al.	7,132,607
	Fujisaki et al.	7,144,687
	Hernandez et al.	7,161,767

[0004] The continuing evolution of disk drive technology requires increasingly smaller head suspensions with enhanced mechanical and electrical performance specifications. There is, therefore, a continuing need for improved integrated lead suspensions and flexures. In particular, there is a need for suspensions and flexures with traces having high bandwidth and low impedance electrical characteristics along with low stiffness and small footprint mechanical properties. Suspensions and flexures of these types with traces that match the different impedances of the preamplifier and write head to which they are connected would be especially desirable. To be commercially viable any such components should also be efficient to manufacture.

[0005] The invention is an integrated lead flexure having traces with enhanced electrical and mechanical properties. In particular, the components can have low impedance and high bandwidth electrical characteristics and low stiffness and small footprint mechanical characteristics. The traces can also be configured to impedance match the preamplifier and write heads to which they are connected.

[0006] An integrated lead head suspension flexure in accordance with one embodiment of the invention has a plurality of regions including a tail and a gimbal. First trace sections having a first structural configuration are on a first region such as the tail. Second trace sections having a second structural configuration different than the first configuration are on the second region such as the gimbal. The second trace sections are electrically connected to the first trace sections. Trace configurations that can be incorporated into the flexure include interleaved traces, stacked traces and ground plane traces. In another embodiment of the invention the first and second trace sections are substantially impedance matched.

[0017] FIG. 1 is a schematic illustration of a wireless or integrated lead flexure 10 having multiple configurations of leads or traces 26 in accordance with a first embodiment of the present invention. As shown, flexure 10 includes a main body region 12, spring-traversing region 13, gimbal 14, tail bend region 15 and a tail 16. Gimbal 14 includes a slider mounting member 18 supported from the main body region 12 by a pair of spring arms 20. The traces 26 electrically interconnect head bond pads 22 on the gimbal 14 to preamplifier terminal pads 24 on the proximal end of tail 16. The slider mounting member 18 and spring arms 20 of gimbal 14, along with other portions of the gimbal and at least portions of the bases of the main body region 12, spring-traversing region 13 and tail 16, include a stainless steel or other spring metal layer 30. Traces 26, bond pads 22 and terminal pads 24 can be formed from one or more layers of conductive material such as copper, nickel, gold and/or alloys. A polyimide or other dielectric insulating layer (not visible in FIG. 1) separates the traces 26, bond pads 22 and terminal pads 24 from the adjacent portions of the spring metal layer 30. Although the embodiment of the invention shown in FIG. 1 has four bond pads 22, terminal pads 24 and associated traces 26, other embodiments of the invention (not shown) have greater numbers of bond pads, terminal pads and traces.

[0018] Flexure 10 is a component that is assembled with other components (not shown) into a head suspension assembly. The main body region 12 of the flexure 10 will typically be welded or otherwise mounted to a rigid beam, with the gimbal 14 extending from the distal end of the rigid beam and the spring-traversing region 13 extending over or around a spring or hinge region. A read/write head is mounted to the slider mounting member 18 of the gimbal 14 and electrically connected to the bond pads 22. Terminal pads 24 are electrically connected to a preamplifier or other electrical component (not shown) of a disk drive into which the head suspension assembly is incorporated. Flexure 10 can be bent or folded at the tail bend region 15 to orient the terminal pads 24 in a plane suitable for connection to the preamplifier.

[0019] Traces 26 include first configuration trace sections 40 on the main body region 12, spring-traversing region 13 and tail 16, and second configuration trace sections 50 on the gimbal 14. In the embodiment shown in FIG. 1 the first trace sections 40 include two sets of interleaved traces 42_1A, 42_1B and 42_2A, 42_2B, and two single traces 42₃ and 42₄. The second trace sections 50 include two ground plane traces 52₁ and 52₂ and two single traces 52₃ and 52₄. Proximal ends of the interleaved traces 42_1A, 42_1B and 42_2A, 42_2B are connected to respective terminal pads 24 by transition structures 60₁ and 60₂ and traces 44₁ and 44₂. The proximal ends of single traces 42₃ and 42₄ are connected directly to the associated terminal pads 24. Distal ends of the interleaved traces 42_1A, 42_1B and 42_2A, 42_2B, are connected to the proximal ends of associated ground plane traces 52₁ and 52₂ by transition structures 62₁ and 62₂. The distal ends of single traces 42₃ and 42₄ are connected directly to the proximal ends of the associated single traces 52₃ and 52₄. The distal ends of the ground plane traces 52₁ and 52₂ and single traces 52₃ and 52₄ are connected directly to the associated bond pads 22.

[0020] FIG. 2 is a detailed illustration of the portion of flexure 10 adjacent the transition structures 60₁ and 60₂ on the tail 16. As shown, interleaved traces 42_1A, 42_1B and 42_2A, 42_2B are located on a surface of a first insulating layer 70 opposite the spring metal layer 30. Transition structure 60₁ is an intersection of the interleaved traces 42_1A and 42_1B on the insulating layer 70. Transition structure 60₂ includes a conductive jumper 72 on a surface of a second insulating layer 74 opposite the interleaved traces 42_1A, 42_1B and 42_2A, 42_2B, and conductive vias 75 extending through the second insulating layer to electrically connect the interleaved traces 42_2A and 42_2B to the jumper. Conductive jumper 72 is connected to an associated terminal pad 24 by trace 44₂ on the same surface of the second insulating layer 74 as the jumper. Trace 44₁ is on the surface of the first insulating layer 70 between the first insulating layer and the second insulating layer 74, and can be connected to an associated terminal pad 24 by structures such as those described below.

[0021] FIG. 3 is a detailed illustration of an alternative transition structure 60₂′ that can be used to connect interleaved traces 42_2A and 42_2B to trace 44₂. As shown, transition structure 60₂′ includes a pair of spaced-apart conductive legs 76 that branch from trace 44₂, extend over an edge of the second insulating layer 74, and into overlapping and electrical contact with the proximal ends of interleaved traces 42_2A and 42_2B. The transition structure 60₂′ can be formed during separate manufacturing steps to extend over the edge of the second insulating layer 74 and into overlapping electrical contact with the previously formed traces 42_2A, 42_2B or trace 44₂. Alternatively, the transition structure 60₂′ can be formed simultaneously with the formation of the traces 42_2A, 42_2B or 44₂.

[0022] Transition structures between other sets of trace configurations can also include plating layers such as that of 60₂′ described in connection with FIG. 3. For example, the transition between stacked traces (e.g., traces 153 and 153₂ in FIG. 6) and ground plane or micro strip traces (e.g., traces 52₁ and 52₂ in FIG. 4) can include a section of conductive plating that extends over an edge of an insulating layer to connect a trace section extending from the top of the insulating layer edge to a trace section extending from the bottom of the insulating layer edge.

[0023] FIGS. 10A-10E are detailed illustrations of the portion of flexure 10 adjacent to traces 44₁ and 44₂ and associated terminal pads 24, with the flexure portion shown at each of a sequence of manufacturing steps. The double plated manufacturing process and structure shown in FIGS. 10A-10E produces terminal pads 24 that are at the same height, even though the traces 44₁ and 44₂ that the terminal pads are connected to are at different levels or heights with respect to the spring metal layer 30. FIG. 10A shows the spring metal layer 30 with an aperture 31 at the locations where the terminal pads 24 will be formed. FIG. 108 shows the first insulating layer 70 over the spring metal layer 30 and aperture 31, with a pair of spaced apertures 33 in the insulating layer over the aperture in the spring metal layer. A first conductor layer is then applied to form trace 44₁ and a first layer of the bond pads 24 as shown in FIG. 10C. The second insulating layer 74 is then applied over the first insulating layer 70 and trace 44₁ as shown in FIG. 10D. An opening 37 is formed in the second insulating layer 74 to expose the apertures 31 and 33 and the first layer of bond pads 24. As shown in FIG. 10E, a second conductor layer is then applied to form a second layer of the terminal pads 24 and the trace 44₂. Other processes and structures (not shown), such as vias, can be used to connect trace 44₁ to the associated terminal pad 24, and to make the terminal pads at the same height, in other embodiments of the invention.

[0024] FIG. 4 is a detailed illustration of the portion of flexure 10 adjacent the transition structures 62₁ and 62₂ near the intersection of the gimbal 14 and main body region 12. The ground plane traces 52₁ and 52₂, which are similar in structure to conventional micro strip conductors, are traces that are backed by an electrically conductive layer. In the embodiment shown in FIG. 4, the ground plane traces 52₁ and 52₂ are backed by a conductive ground plane layer 80 formed on the spring metal layer 30. Traces 52₁ and 52₂ are formed on the surface of a first insulating layer 70 that separates the traces from the ground plane layer 80. Other embodiments of the ground plane traces 52₁ and 52₂ (not shown) are backed by the spring metal layer and do not have an additional ground plane layer such as 80.

[0025] Transition structure 62₂ is an intersection of the interleaved traces 42_2A and 42_2B on the insulating layer 70. Transition structure 62₁ includes a spring metal island 82 in the spring metal layer 30 below the interleaved traces 42_1A, 42_1B and 42_2A, 42_2B, and conductive vias 84 extending through the insulating layer 70 to electrically connect the interleaved traces 42_1A and 42_1B to the spring metal island 82. The spring metal island 82 is separated and electrically isolated from adjacent portions of the spring metal layer 30 by space 83, and electrically interconnects the interleaved traces 42_1A and 42_1B through vias 84.

[0026] The thickness, width, spacing between and/or other features of the interleaved traces 42_1A, 42_1B and 42_2A, 42_2B can be varied to vary the impedance of the traces along their lengths. Similarly, features of the ground plane traces 52₁ and 52₂ (e.g., width, spacing, insulating layer thickness and dielectric constant) can be varied to change the impedance of the traces along their lengths. In one embodiment of the invention, for example, first trace sections 40 and the second trace sections 50 are impedance matched and configured so their impedances continuously vary between a first impedance at the terminal pads 24 (e.g., about 65 ohms) that substantially matches the impedance of the disk drive circuitry to which the terminal pads are connected, and a second impedance at the bond pads 22 (e.g., about 15 ohms) that substantially matches the impedance of the read/write head mounted to the slider mounting member 18. Trace structures capable of providing variable impedance features are disclosed, for example, in the following commonly assigned U.S. patent applications: Ser. No. 11/744,623, filed May 4, 2007, entitled Integrated Lead Head Suspension With Tapered Trace Spacing; Ser. No. 11/744,644, filed May 4, 2007, entitled Disk Drive Head Suspension Flexures Having Alternating Width Stacked Leads; and provisional application Ser. No. 60/991,165, filed Oct. 9, 2007, entitled Constant Impedance and Variable Bandwidth Traces For An Integrated Lead Suspension. Other transition structures can also be used in the flexure 10, including for example those shown in commonly assigned U.S. provisional application Ser. No. 60/916,201, filed May 4, 2007, entitled Trace Jumpers For Disk Drive Suspensions. Conventional or otherwise known photolithography, deposition and etching process such as those disclosed, for example, in the Swanson U.S. published patent application no. 2005/0254175, can be used to manufacture flexure 10. All of the above-mentioned patent applications are incorporated herein in their entirety by reference.

[0027] In one embodiment of the invention the interleaved traces 42_1A, 42_1B and 42_2A, 42_2B can have a width foot print of about 300 μm and a 65 ohm impedance. Other embodiments of the invention have interleaved traces with foot prints between about 100 μm and 600 μm. The ground plane traces can provide an impedance of about 15-25 ohms. These examples are non-limiting. Larger and/or smaller footprints and impedances can be used in other embodiments.

[0028] Integrated lead flexure 10 offers a number of important advantages. The interleaved first trace sections 40 can provide desirable electrical characteristics such as the high bandwidth and mid range impedance values suitable for impedance matching to disk drive circuits connected to the terminal pads 24 on the tail 16. The ground plane second trace sections 50 can be made relatively narrow and thin to provide relatively low stiffness and small footprint mechanical characteristics desirable on the gimbal 14 of the flexure 10. The relatively low impedance of the ground plane second trace sections 50 is suitable for impedance matching to the read write heads connected to bond pads 22 on the gimbal. The varying features of the traces 26, especially the first trace sections 40, enables the continuous impedance matching transition between the impedances at the bond pads 22 and termination pads 24 to further enhance the electrical characteristics of the flexure 10.

[0029] The invention enables electrical performance to be maximized while still maintaining mechanical performance in mechanically critical areas. The location of the transition between different trace configurations can be chosen to optimize the balance between electrical and mechanical performances. Although the transition between the trace configurations is located between the main body region 12 and gimbal 14 in flexure 10, the transition is located at other mechanically critical locations in other embodiments (not shown) such as the spring-traversing region 13 and the tail bend region 15. The electrical performance of traces at these regions can then be optimized without substantially sacrificing the mechanical performance in mechanically critical areas. Similarly, trace structures that optimize electrical performance can be incorporated into non-mechanically critical areas of the flexure.

[0030] FIG. 5 is a schematic illustration of a wireless or integrated lead flexure 110 having multiple configurations of traces 126 in accordance with a second embodiment of the invention. As shown, flexure 110 includes a main body region 112, spring-traversing region 113, gimbal 114, tail bend region 115 and a tail 116. Gimbal 114 includes a slider mounting member 118 supported from the main body region 112 by a pair of spring arms 120. The traces 126 electrically interconnect head bond pads 122 on the gimbal 114 to preamplifier terminal pads 124 on the proximal end of tail 116. The slider mounting member 118 and spring arms 120 of gimbal 114, along with other portions of the gimbal and the base of main body region 112 and tail 116, include a stainless steel or other spring metal layer 130. Traces 126, bond pads 122 and terminal pads 124 can be formed from one or more layers of conductive material such as copper, nickel, gold and/or alloys. A polyimide or other dielectric insulating layer (not visible in FIG. 5) separates the traces 126, bond pads 122 and terminal pads 124 from the adjacent portions of the spring metal layer 130. Although the embodiment of the invention shown in FIG. 5 has four bond pads 122, terminal pads 124 and associated traces 126, other embodiments of the invention (not shown) have greater numbers of bond pads, terminal pads and traces.

[0031] Traces 126 include first configuration trace sections 140 on the main body region 112, spring-traversing region 113 and tail 116, and second configuration trace sections 150 on the gimbal 114. In the embodiment shown in FIG. 5 the first trace sections 140 include two sets of interleaved traces 142_1A, 142_1B and 142_2A, 142_2B, and two single traces 142₃ and 142₄. The second trace sections 150 include two stacked traces 153₁ and 153₂ and two single traces 152₃ and 152₄. Proximal ends of the interleaved traces 142_1A, 142_1B and 142_2A, 142_2B are connected to respective terminal pads 124 by transition structures 160₁ and 160₂ and traces 144₁ and 144₂ (e.g., using double plated structures such as those described above in connection with FIGS. 10A-10E). The proximal ends of single traces 142₃ and 142₄ are connected directly to the associated terminal pads 124. Distal ends of the interleaved traces 142_1A, 142_1B and 142_2A, 142_2B are connected to the proximal ends of associated stacked traces 153₁ and 153₂ by transition structures 163₁ and 163₂. The distal ends of single traces 142₃ and 142₄ are connected directly to the proximal ends of the associated single traces 152₃ and 152₄. The distal ends of the single traces 152₃ and 152₄ are connected directly to the associated bond pads 122. The stacked traces 153₁ and 153₂ can be connected to bond pads 122 by structures similar to those of the double plated structures described above in connection with FIGS. 10A-10E or other structures such as vias (not shown). With the exception of stacked traces 153₁ and 153₂ and transition structures 163₁ and 163₂ which are described below, flexure 110 can be substantially the same as or similar to flexure 10 described above, and similar features are identified by similar reference numbers. Flexure 110 can also be manufactured using processes substantially the same as or similar to those described above in connection with flexure 10.

[0032] FIG. 6 is a detailed illustration of the portion of flexure 110 adjacent the transition structures 163₁ and 163₂. As shown, interleaved traces 142_1A, 142_1B and 142_2A, 142_2B are located on a surface of a first insulating layer 170 opposite the spring metal layer 130. Transition structure 163₂ is an intersection of the interleaved traces 142_2A and 142_2B on the insulating layer 170. Transition structure 163₁ includes a conductive jumper 172 on a surface of a second insulating layer 174 opposite the interleaved traces 142_1A, 142_1B and 142_2A, 142_2B, and conductive vias 175 extending through the second insulating layer to electrically connect the interleaved traces 142_1A and 142_1B to the jumper. Conductive jumper 172 is connected to an associated bond pad 122 by stacked trace 153₁ on the same surface of the second insulating layer 174 as the jumper. Stacked trace 153₂ is on the surface of the first insulating layer 170, opposite the second insulating layer 174 from stacked trace 153₁. As noted above, stacked trace 153₂ can be electrically connected to an associated bond pad 122 by the double plated structures described in connection with FIGS. 10A-10E. Other embodiments of the invention (not shown) include alternative transition structures such as those described above in connection with flexure 10.

[0033] In one embodiment of flexure 110 the interleaved traces 142_1A, 142_1B and 142_2A, 142_2B are each about 30 μm wide and together have a maximum foot print of about 300 μm. The interleaved traces 142_1A, 142_1B and 142_2A, 142_2B have an impedance of about 65 ohms at the terminal pads 124. Stacked traces 153₁ and 153₂ can be about 50 μm wide, separated by a polyimide insulating layer 174 about 5 μm thick, and have an impedance at bond pads 124 of about 15-25 ohms. Other embodiments of the invention include traces having larger and/or smaller width, foot prints, impedances, thicknesses and other features and characteristics.

[0034] Integrated lead flexure 110 offers a number of important advantages. The interleaved first trace sections 140 can provide desirable electrical characteristics such as the high bandwidth and mid range impedance values suitable for impedance matching to disk drive circuits connected to the terminal pads 124 on the tail 116. The stacked traces 153₁ and 153₂ can be made relatively narrow and thin to provide relatively low stiffness and small footprint mechanical characteristics desirable on the gimbal 114 of the flexure 110. The relatively low impedance of the stacked second trace sections 150 is suitable for impedance matching to the read write heads connected to bond pads 122 on the gimbal 114. The varying features of the traces 126, especially the first trace sections 140, enables a continuous impedance matching transition between the impedances at the bond pads 122 and termination pads 124 to further enhance the electrical characteristics of the flexure 110.

[0035] FIG. 7 is a schematic illustration of a wireless or integrated lead flexure 210 having multiple configurations of traces 226 in accordance with a third embodiment of the invention. As shown, flexure 210 includes a main body region 212, spring-traversing region 213, gimbal 214, tail bend region 215 and a tail 216. Gimbal 214 includes a slider mounting member 218 supported from the main body region 212 by a pair of spring arms 220. The traces 226 electrically interconnect head bond pads 222 on the gimbal 214 to preamplifier terminal pads 224 on the proximal end of tail 216. The slider mounting member 218 and spring arms 220 of gimbal 214, along with other portions of the gimbal and the base of main body region 212 and tail 216, are formed from a stainless steel or other spring metal layer 230. Traces 226, bond pads 222 and terminal pads 224 can be formed from one or more layers of conductive material such as copper, nickel, gold and/or alloys. A polyimide or other dielectric insulating layer (not visible in FIG. 7) separates the traces 226, bond pads 222 and terminal pads 224 from the adjacent portions of the spring metal layer 230. Although the embodiment of the invention shown in FIG. 7 has four bond pads 222, terminal pads 224 and associated traces 226, other embodiments of the invention (not shown) have greater numbers of bond pads, terminal pads and traces.

[0036] Traces 226 include first configuration trace sections 240 on the main body region 212, tail-traversing region 213 and tail 216, and second configuration trace sections 250 on the gimbal 214. In the embodiment shown in FIG. 7 the first trace sections 240 include two stacked traces 244₁, and 244₂ and two single traces 242₃ and 242₄. The second trace sections 250 include two sets of interleaved traces 254_1A, 254_1B and 254_2A, 254_2B, and two single traces 252₃ and 252₄. Proximal ends of the stacked traces 244₁, and 244₂ are connected to respective terminal pads 224 by double plated structures such as those described above in connection with FIGS. 10A-10E or other structures (not shown). The proximal ends of single traces 242₃ and 242₄ are connected directly to the associated terminal pads 224. Distal ends of the stacked traces 244₁ and 244₂ are connected to the proximal ends of interleaved traces 254_1A, 254_1B and 254_2A, 254_2B by transition structures 264₁ and 264₂. The distal ends of the interleaved traces 254_1A, 254_1B and 254_2A, 254_2B are connected to respective bond pads 222 by transition structures 265₁ and 265₂, traces 245₁ and 245₂ and structures such as the double plated structures described above in connection with FIGS. 10A-10E. The distal ends of single traces 242₃ and 242₄ are connected directly to the proximal ends of the associated single traces 252₃ and 252₄. The distal ends of the single traces 252₃ and 252₄ are connected directly to the associated bond pads 222.

[0037] The stacked traces 244₁ and 244₂ can be the substantially the same as or similar to the stacked traces 153₁ and 153₂ described above in connection with flexure 110. The interleaved traces 254_1A, 254_1B and 254_2A, 254_2B can be substantially the same as or similar to the interleaved traces 42_1A, 42_1B and 42_2A, 42_2B, of the flexure 10. The transition structures 264₁ and 264₂ between the stacked first trace sections 240 and the interleaved second trace sections 250 can be substantially the same as or similar to the transition structures 163₁ and 163₂ of flexure 110. Transition structures 265₁ and 265₂ between the interleaved second trace sections 250 and the traces 245₁ and 245₂ connected to the bond pads 222 can be substantially the same as or similar to the transition structures 60₁ and 60₂ of flexure 10. Flexure 210 can be manufactured using processes substantially the same as or similar to those described above in connection with flexure 10. Flexure 210 offers advantages similar to those described above in connection with flexures 10 and 110. In particular, flexure 210 allows optimal mechanical properties and maximizes electrical performance in areas other an the gimbal (e.g., in the tail bend and radius regions). These characteristics can, for example, be useful in flexures where characteristics of the tail, tail bend or spring-traversing regions are more critical than those of the gimbal.

[0038] FIG. 8 is a schematic illustration of a wireless or integrated lead flexure 310 having multiple configurations of traces 326 in accordance with a fourth embodiment of the invention. As shown, flexure 310 includes a base or main body region 312, spring-traversing region 313, gimbal 314, tail bend region 315 and a tail 316. Gimbal 314 includes a slider mounting member 318 supported from the main body region 312 by a pair of spring arms 320. The traces 326 electrically interconnect head bond pads 322 on the gimbal 314 to preamplifier terminal pads 324 on the proximal end of tail 316. The slider mounting member 318 and spring arms 320 of gimbal 314, along with other portions of the gimbal and the base of main body region 312 and tail 316, are formed from a stainless steel or other spring metal layer 330. Traces 326, bond pads 322 and terminal pads 324 can be formed from one or more layers of conductive material such as copper, nickel, gold and/or alloys. A polyimide or other dielectric insulating layer (not visible in FIG. 8) separates the traces 326, bond pads 322 and terminal pads 324 from the adjacent portions of the spring metal layer 330. Although the embodiment of the invention shown in FIG. 8 has four bond pads 322, terminal pads 324 and associated traces 326, other embodiments of the invention (not shown) have greater numbers of bond pads, terminal pads and traces.

[0039] Traces 326 include first configuration trace sections 340 on the main body region 312 and tail 316 and second configuration trace sections 350 on the gimbal 314. In the embodiment shown in FIG. 8 the first trace sections 340 include two stacked traces 344₁, and 344₂ and two single traces 342₃ and 342₄. The second trace sections 350 include two ground plane traces 352₁ and 352₂, and two single traces 352₃ and 352₄. Proximal ends of the stacked traces 344₁, and 344₂ are connected to respective terminal pads 324 by structures such as the double plated structures described above in connection with FIGS. 10A-10E. The proximal ends of single traces 342₃ and 342₄ are connected directly to the associated terminal pads 324. Distal ends of the stacked traces 344₁ and 344₂ are connected to the proximal ends of ground plane traces 352₁ and 352₂ by transition structure 365. The distal ends of the ground plane traces 352₁ and 352₂ and single traces 352₃ and 352₄ are connected directly to respective bond pads 322. The distal ends of single traces 342₃ and 342₄ are connected directly to the proximal ends of the associated single traces 352₃ and 352₄.

[0040] FIG. 9 is a detailed illustration of the portion of flexure 310 adjacent the transition structure 365 near the intersection of the gimbal 314 and main body region 312. As shown, ground plane traces 352₁ and 352₂ and stacked trace 344₂ are on the surface of first insulating layer 370 opposite the spring metal layer 330. A conductive ground plane layer 380 is located on the spring metal layer 330, below the first insulating layer 370 and the ground plane traces 352₁ and 352₂, throughout all or at least a substantial portion of the second trace sections 350. In other embodiments (not shown) the spring metal layer 330 functions as the ground plane layer. Stacked trace 344₂ extends directly from ground plane trace 352₁ on the surface of the first insulating layer 370. A second insulating layer 371 extends over the ground plane traces 352₁ and 352₂ and the stacked trace 344₂. Transition structure 365 includes a conductive via 384 extending through the insulating layer 370 to electrically connect the ground plane trace 352₂ to the stacked trace 344₁.

[0041] The stacked traces 344₁ and 344₂ can be the substantially the same as or similar to the stacked traces 153₁ and 153₂ described above in connection with flexure 110. The ground plane traces 352₁ and 352₂ can be substantially the same as or similar to the ground plane traces 52₁ and 52₂ of the flexure 10. Flexure 310 can be manufactured using processes substantially the same as or similar to those described above in connection with flexure 10.

[0042] Although the present invention has been described with reference to preferred embodiments, those skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the invention. For example, although two different configurations of trace sections are shown in the illustrated examples, other embodiments (not shown) can have additional and/or different trace sections on portions of the tail, tail bend, mounting region, spring-traversing region and/or gimbal. Other trace configurations (e.g., single traces with no ground plane or windows in the stainless steel layer) can also be used, as can other combinations of these traces configurations.