Electrical lead suspension having partitioned air slots

An electrical lead suspension (ELS) having partitioned air slots. The ELS includes a laminate. A first plurality of signal traces and a second plurality of traces are in a first formed layer of the laminate. The second plurality of traces may be signal traces or power traces. The laminate has a dielectric layer between the first formed layer and a second formed layer. A plurality of partitioned air slots is in the second formed layer of the laminate. The portion of the ELS having a plurality of partitioned air slots supporting the at least the first plurality of signal traces and the portion of the ELS having a second plurality of partitioned air slots or patterns supporting the second plurality of traces. The supporting of the first plurality of signal traces separate from the second plurality of traces reduces write-to-read cross talk and signal loss. Offsetting the first plurality of air slots from second plurality of air slots further reduces cross talk and signal loss and restores some of the structural rigidity lost due to in line (e.g., aligned) slots.

TECHNICAL FIELD

The present invention relates to the field of electrical interconnect, and more particularly to an electrical lead suspension having partitioned air slots.

BACKGROUND ART

Hard disk drives are used in almost all computer system operations. In fact, most computing systems are not operational without some type of hard disk drive to store the most basic computing information such as the boot operation, the operating system, the applications, and the like. In general, the hard disk drive is a device which may or may not be removable, but without which the computing system will generally not operate.

The basic hard disk drive model was established approximately 50 years ago and resembles a phonograph. That is, the hard drive model includes a storage disk or hard disk that spins at a standard rotational speed. An actuator arm with a suspended slider is utilized to reach out over the disk. The arm carries a head assembly that has a magnetic read/write transducer or head for reading/writing information to or from a location on the disk. The complete head assembly, e.g., the suspension and head, is called a head gimbal assembly (HGA).

In operation, the hard disk is rotated at a set speed via a spindle motor assembly having a central drive hub. Additionally, there are tracks evenly spaced at known intervals across the disk. When a request for a read of a specific portion or track is received, the hard disk aligns the head, via the arm, over the specific track location and the head reads the information from the disk. In the same manner, when a request for a write of a specific portion or track is received, the hard disk aligns the head, via the arm, over the specific track location and the head writes the information to the disk.

Over the years, the disk and the head have undergone great reductions in their size. Much of the refinement has been driven by consumer demand for smaller and more portable hard drives such as those used in personal digital assistants (PDAs), MP3 players, and the like. For example, the original hard disk drive had a disk diameter of 24 inches. Modern hard disk drives are much smaller and include disk diameters of less than 2.5 inches (micro drives are significantly smaller than that). Advances in magnetic recording are also primary reasons for the reduction in size.

However, the decreased track spacing and the overall reduction in HDD component size and weight have resulted in problems with respect to the electrical lead suspension (henceforth referred to as ELS), used in a Data Access Storage Device (DASD), e.g., a hard disk drive (HDD). For example, a typical ELS is formed from a laminate comprised of at least three layers of material. These laminate layers may include a signal-conductor layer from which signal traces are formed, a dielectric layer for insulation supporting the signal-conductor layer, and a conductive base-metal layer supporting the dielectric layer.

Prior ArtFIG. 1is a top plan view100of an ELS tail portion having write traces120and read traces130formed from the signal-conductor layer above a laminate dielectric layer. The dielectric layer is provided above the base-metal layer of the laminate. The supporting base-metal layer is formed having continous airslots under the read130write120pairs, so as to allow the head to fly properly and providing the necessary amount of mechanical stiffness for supporting the signal traces120and130that are the read and write traces. While the slotted base-metal layer can provide the appropriate mechanical stiffness, this metal layer and continous airslots underneath the read and write traces120and130results in write-to-read cross-talk that degrades the performance of the read sensor. For example, the read traces130connect to a voltage-sensitive read sensor. However, the write driver utilizes a large voltage to produce a current in the write traces120that will interact with the base-metal layer110and produce a current in read traces130. This production of non-desired current in read traces130from the voltage applied to write traces130is detrimental to the overall function of the ELS. Moreover, as the size of the ELS is reduced, the amount of voltage required by the write traces120to cause interference with the read traces130is also reduced.

SUMMARY

An electrical lead suspension (ELS) having partitioned air slots. The ELS includes a laminate. A first plurality of signal traces and a second plurality of traces are in a first formed layer of the laminate. The second plurality of traces may be signal traces or power traces. The laminate has a dielectric layer between the first formed layer and a second formed layer. A plurality of partitioned air slots is in the second formed layer of the laminate. The portion of the ELS having a plurality of partitioned air slots supporting the at least the first plurality of signal traces and the portion of the ELS having a second plurality of partitioned air slots or patterns supporting the second plurality of traces. The supporting of the first plurality of signal traces separate from the second plurality of traces reduces write-to-read cross talk and signal loss. Offsetting the first plurality of air slots from second plurality of air slots further reduces cross talk and signal loss and restores some of the structural rigidity lost due to in line (e.g., aligned) slots.

BEST MODES FOR CARRYING OUT THE INVENTION

Reference will now be made in detail to the alternative embodiment(s)s of the present invention, an electrical lead suspension having partitioned air slots. While the invention will be described in conjunction with the alternative embodiment(s), it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims.

The discussion will begin with an overview of an electrical lead suspension (ELS) in conjunction with its operation within a hard disk drive and components connected therewith. The discussion will then focus on embodiments of a method for an electrical lead suspension having partitioned air slots in particular.

With reference now toFIG. 2, a schematic drawing of one embodiment of an information storage system comprising a magnetic hard disk file or drive111for a computer system is shown. Drive111has an outer housing or base113containing a disk pack having at least one media or magnetic disk115. A spindle motor assembly having a central drive hub117rotates the disk or disks115. An actuator121comprises a plurality of parallel actuator arms125(one shown) in the form of a comb that is movably or pivotally mounted to base113about a pivot assembly123. A controller119is also mounted to base113for selectively moving the comb of arms125relative to disk115.

In the embodiment shown, each arm125has extending from it at least one cantilevered load beam and electrical lead suspension (ELS)127. It should be understood that ELS127may be, in one embodiment, an integrated lead suspension (ILS) that is formed by a subtractive process. In another embodiment, an additive process, such as a Circuit Integrated Suspension (CIS), may form ELS127. In yet another embodiment, ELS127may be a Flex-On Suspension (FOS) attached to base-metal or it may be a Flex Gimbal Suspension Assembly (FGSA) that is attached to a base-metal layer. The ELS may be any form of lead suspension that can be used in a Data Access Storage Device, such as a HDD. A magnetic read/write transducer or head is mounted on a slider129and secured to a flexure that is flexibly mounted to each ELS127. The read/write heads magnetically read data from and/or magnetically write data to disk115. The level of integration called the head gimbal assembly is the head and the slider129, which are mounted on ELS127. The slider129is usually bonded to the end of ELS127.

ELS127has a spring-like quality, which biases or presses the air-bearing surface of the slider129against the disk115to cause the slider129to fly at a precise distance from the disk. ELS127has a hinge area that provides for the spring-like quality, and a flexing interconnect (or flexing interconnect) that supports read and write traces through the hinge area. A voice coil133, free to move within a conventional voice coil motor magnet assembly134(top pole not shown), is also mounted to arms125opposite the head gimbal assemblies. Movement of the actuator121(indicated by arrow135) by controller119causes the head gimbal assemblies to move along radial arcs across tracks on the disk115until the heads settle on their set target tracks. The head gimbal assemblies operate in a conventional manner and always move in unison with one another, unless drive111uses multiple independent actuators (not shown) wherein the arms can move independently of one another.

Although embodiments of the present invention are described in the context of an ELS in an information storage system, it should be understood that embodiments may apply to any device utilizing an electrical interconnect that might experience signal loss and cross talk between signal traces. For example, embodiments of the present invention may apply to rigid printed circuit boards. More specifically, embodiments of the present invention may be used in printed circuit boards that are used for high speed signal processing. Embodiments of the present invention are also suitable for use in flexing circuits, e.g., flexing circuits for digital cameras and digital camcorders. The signal traces may also be replaced with power traces according to one embodiment.

FIG. 3is a top plan view of a tail portion309of the ELS127that has a base-metal layer802(seeFIG. 8) with dual air slots430aand430b(e.g., microwindows) in at least the tail portion309of the ELS127ofFIG. 2, in accordance with an embodiment of the present invention. In one embodiment, the slots in two rows of partitioned air slots are aligned such as those further described in the discussion ofFIG. 4a. In another embodiment, the air slots in the two rows of air slots are offset such as those further described in the discussion ofFIG. 4b. In yet another embodiment, the air slots430aand430bare a combination of aligned partitioned dual air slots such as those further described in the discussion ofFIG. 4aandFIG. 4b.

In one embodiment, the air slot patterns430aand430bare both sets of repeating narrow open air slots, formed in the stainless steel ground plane802in a location which would be under one of each signal conductor pair (e.g., read130/write120traces ofFIGS. 4aand4b) on a tail portion of the ELS. The added air slots, e.g.,430aand/or430b, reduce signal amplitude loss by disrupting/reducing flow of differential return currents between the read and write traces such as those shown inFIGS. 4aand4b. Also, the independent and unconnected air slots in the ground plane reduce read to write coupling/cross talk between the read and write traces such as those shown inFIGS. 4aand4b. In another embodiment, described herein, the airslots or microwindows are used in other areas of the ELS127including the flexible hinge area.

FIG. 4ais a top view of a portion400of an ELS tail portion, e.g., ELS tail portion309ofFIG. 3and/or a flexing interconnect, e.g. flexing interconnect300ofFIG. 5, having write traces120and read traces130formed of the signal-conductor layer supported individually by dielectric layer, and then a first support410ahaving air slot pattern430aand a second support410bhaving air slot pattern430b, wherein the first air slot pattern430aand the second air slot pattern430bare aligned with one another with a partition440in between to form a dual air slot pattern formed of a base-metal layer, in accordance with one embodiment of the present invention. In one embodiment, the aligned and partitioned air slot pattern is used in a high data rate interconnect having independent air slots in the electrical lead suspension.

In one embodiment, the air slot patterns are both sets of repeating narrow open air slots, e.g.,430aand430brespectively, formed in the stainless steel ground plane802under each signal conductor pair (e.g., read130/write120traces) on a tail portion of the ELS or other portion of the ELS such as the suspension interconnect portion. The added air slots, e.g.,430aand430b, reduce signal amplitude loss by disrupting/reducing flow of differential return currents. Also, the independent offset and unconnected air slots, e.g.,430aand430b, in the ground plane802for each conductor pair, reduce read to write coupling/cross talk.

For example, the portion400ofFIG. 4acomprises a laminate for supporting attached devices, according to one embodiment of the present invention. A plurality of read traces130are formed of the signal-conductor layer, according to one embodiment, as are a plurality of write traces120. Supports410aand410bare formed of a layer, e.g., base-metal layer802ofFIG. 8, of the laminate. The first dual air slot pattern430ais under the plurality of write traces120and the second dual air slot pattern430bis under the plurality of read traces130above the ELS127. In so doing, the aligned and partitioned air slot pattern under the plurality of write traces120separate from the plurality of read traces130reduces write-to-read cross talk and signal loss.

That is, in one embodiment, the air slots430aand430bare 30 to 50 μm wide and go across both conductors in a pair as shown. Instead of using a common slot for both read130and write120conductor pairs, each pair has a partition portion440. That is, the air slots430aof support portion410aunder write traces120are separated from the air slots430bof support portion410bunder read traces130by the partition440. The added partition440to the air slots disrupt/reduce the flow of differential return currents in the ground plane802resulting in lower signal loss throughout the tail portion of the ELS. Also independent and unconnected air slots430aand430bin the ground plane802for each conductor pair reduce read to write coupling and work like a shield against cross talk between adjacent signal conductor pairs and surrounding interference signals inside the hard-disk-drive111enclosure.

According to one embodiment, the layered laminate from which the ELS127is formed comprises at least a signal-conductor layer, e.g. copper alloy, a dielectric layer, e.g. polyimide, and a base-metal layer, e.g. stainless steel. The dielectric layer is sandwiched between the signal-conductor layer and the base-metal layer to form a laminate. The plurality of read traces130and the plurality of write traces120can be formed of the layer of signal-conductor layer. Although copper alloy is specified herein, it should be understood that any material having high electrical conductivity, from which write traces120and read traces130can be formed, may be substituted for the copper alloy. The dielectric layer can be any dielectric that would be appropriate for insulating the read and write traces from the supporting base-metal layer.

Still referring toFIG. 4a,the dual air slots430aand430bare formed of the base-metal layer, according to one embodiment. This layer may be stainless steel, or it may be any base-metal that would have the appropriate mechanical stiffness, electrical characteristics and manufacturability needed. Refer toFIG. 8for further details of the electrical characteristics.

According to one embodiment of the present invention, the mechanical stiffness of tail portion309ofFIG. 3and further the flexing interconnect300of theFIG. 5, and portion400thereof ofFIG. 4a, is also affected by the period and the geometry of the air slots430aand430b. The geometries of at least one pattern of dual offset air slots430aand430bare alterable to achieve a predefined mechanical stiffness. A compromise may be reached to achieve both an acceptable mechanical stiffness and characteristic impedance for signal traces.

In one embodiment, supports410aand410bare formed from a single piece of a base-metal layer to form the desired partitioned air slot pattern. In another embodiment, supports410aand410bare formed from two pieces of a base-metal layer that are fit together to form the desired dual partitioned air slot pattern. In yet another embodiment, supports410aand410bare formed from a plurality of pieces of a base-metal layer that are fit together to form the desired partitioned air slot pattern. In one embodiment, the air slot patterns are formed in the base-metal layer via stamping, etching, molding, casting, cutting or the like.

FIG. 4bis a top view of a portion450of an ELS tail portion, e.g., ELS tail Portion309ofFIG. 3and/or a flexing interconnect, e.g. flexing interconnect300ofFIG. 5, having write traces120and read traces130formed of the signal-conductor layer supported individually by dielectric layer, and then a first support455ahaving air slot pattern460atherein and a second support455bhaving air slot pattern460btherein, wherein the first air slot pattern460aand the second air slot pattern460bare offset and independent from one another to form a dual offset air slot pattern of the flexing interconnect support formed of a base-metal layer, in accordance with one embodiment of the present invention.

In one embodiment, the air slot patterns are both sets of repeating narrow open air slots, e.g.,460aand460brespectively, formed in the stainless steel ground plane802under each signal conductor pair (e.g., read130/write120traces) on a portion of the ELS127such as on the tail portion, a suspension interconnect, or the like. The added air slots, e.g.,460aand460b, reduce signal amplitude loss by disrupting/reducing flow of differential return currents. Also, the independent offset and unconnected air slots, e.g.,460aand460b, in the ground plane802for each conductor pair, reduce read to write coupling/cross talk.

For example, the portion450ofFIG. 4bcomprises a laminate for supporting attached devices, according to one embodiment of the present invention. A plurality of read traces130are formed of the signal-conductor layer, according to one embodiment, as are a plurality of write traces120. Supports455aand455bare formed of a layer, e.g., base-metal layer802ofFIG. 8, of the laminate. The first dual offset air slot pattern460ais under the plurality of write traces120and the second offset air slot pattern460bis under the plurality of read traces130above at least a portion of the ELS such as the tail portion309ofFIG. 3, the hinge area370ofFIG. 5, or the like. In so doing, the dual offset air slot pattern under the plurality of write traces120separate from the plurality of read traces130reduces write-to-read cross talk and signal loss.

That is, in one embodiment, the air slots460aand460bare 30 to 50 μm wide and go across both conductors in a pair as shown. Instead of using a common slot for both read130and write120conductor pairs, each pair has a separate series of slots offset from the other one. That is, the air slots of460aunder write traces120are offset from the air slots460bunder read traces130. The added offset air slots disrupt/reduce the flow of differential return currents in the ground plane802resulting in lower signal loss. Also independent, offset and unconnected air slots460aand460bin the ground plane802for each conductor pair, reduce read to write coupling and work like a shield against cross talk between adjacent signal conductor pairs and surrounding interference signals inside the hard disk-drive111enclosure.

According to one embodiment, the layered laminate from which the structure450is formed comprises at least a signal-conductor layer, e.g. copper alloy, a dielectric layer, e.g. polyimide, and a base-metal layer, e.g. stainless steel. The dielectric layer is sandwiched between the signal-conductor layer and the base-metal layer to form a laminate. The plurality of read traces130and the plurality of write traces120can be formed of the layer of signal-conductor layer. Although copper alloy is specified herein, it should be understood that any material having high electrical conductivity, from which write traces120and read traces130can be formed, may be substituted for the copper alloy. The dielectric layer can be any dielectric that would be appropriate for insulating the read and write traces from the supporting base-metal layer.

Still referring toFIG. 4b, the dual offset supports455aand455bare formed of the base-metal layer, according to one embodiment. This layer may be stainless steel, or it may be any base-metal that would have the appropriate mechanical stiffness, electrical characteristics and manufacturability needed. Refer toFIG. 8for further details of the electrical characteristics.

According to one embodiment of the present invention, the mechanical stiffness of the ELS127, and portion450thereof ofFIG. 4b, is also affected by the period and the geometry of the offset air slots460aand460bwithin the supports455aand455b. The geometries of at least one pattern455aor455bof dual offset air slots460aand460bare alterable to achieve a predefined mechanical stiffness. A compromise may be reached to achieve both an acceptable mechanical stiffness and characteristic impedance for signal traces.

In one embodiment, supports455aand455bare formed from two pieces of a base-metal layer that are fit together to form the desired dual offset air slot pattern. In another embodiment, supports455aand455bare formed from a single piece of a base-metal layer to form the desired dual offset air slot pattern. In yet another embodiment, supports455aand455bare formed from a plurality of pieces of a base-metal layer that are fit together to form the desired dual offset air slot pattern. In one embodiment, the offset patterns are formed in the base-metal layer via stamping, etching, molding, casting, cutting or the like.

In one embodiment, the air slot pattern410ais a set of repeating narrow open air slots formed in the stainless steel ground plane802under one signal conductor pair (e.g., read130or write120traces) on a tail portion of the ELS or other portion of the ELS such as the suspension interconnect portion.

The single air slot pattern410akeeps the plurality of write traces120separate from the plurality of read traces130reduces write-to-read cross talk and signal loss.

In one embodiment, the air slots410aare 30 to 50 μm wide and go under one of the conductor pairs. Instead of using a common slot for both read130and write120conductor pairs, only one pair has an air slot. That is, the air slots (eg.,410aor410bofFIG. 4a) is either under write traces120or under read traces130but not both. Thus, the air slots disrupt/reduce the flow of differential return currents in the ground plane802resulting in lower signal loss throughout the tail portion of the ELS. Also independent and unconnected air slots (e.g.,410aor410bofFIG. 4a)in the ground plane802for each conductor pair reduce read to write coupling and work like a shield against cross talk between adjacent signal conductor pairs and surrounding interference signals inside the disk111enclosure.

With reference now toFIG. 5, a top plan view of an ELS127having a flexing interconnect300, according to one embodiment of the present invention. The read and write traces,130and120, respectively, pass through the hinge center370of ELS127, where loadbeam340connects, via hinge plate350, to mount plate360, according to one embodiment of the present invention. A slider resides toward the end1290f ELS127, and contains the read/write head.The slider is bonded to read and write traces130and120, respectively, where read and write signals are carried to and from the read/write head.

Flexing interconnect300of ELS127can be formed of a laminate that is, according to one embodiment, of at least three layers of materials. A signal-conductor layer may be a highly conductive metal, e.g., copper, from which the read and write traces130and120, respectively are formed. A middle layer can be an insulating dielectric layer, e.g., polyimide, separating the top layer from which write and read traces120and130respectively, are formed of a base-metal layer802, such as stainless steel, in which offset air slots are formed.

FIG. 6ais a bottom plan view600of an ELS127showing dual air slot pattern supports410aand410bhaving dual air slots e.g.,430aand430bofFIG. 4a, as they traverse the center of hinge area370and onto hinge plate350of ELS127, in accordance with an embodiment of the present invention. In another embodiment, write traces120and read traces130may be supported by supports455aand455bhaving offset and independent dual airslots e.g.,460aand460bofFIG. 4b, or a combination thereof anywhere along the tail portion309of ELS127.

FIG. 6bis a bottom plan view650of an ELS127showing dual offset air slot pattern supports455aand455bhaving offset and independent dual airslots e.g.,460aand460bofFIG. 4bas they traverse the center of hinge area370and onto hinge plate350of ELS127, in accordance with an embodiment of the present invention. In another embodiment, write traces120and read traces130may be supported by aligned and partitioned supports410aand410bhaving dual air slots e.g.,430aand430bofFIG. 4a, or a combination thereof anywhere along the tail portion309of ELS127.

FIG. 7is a flow diagram of a method700for reducing cross talk and signal loss in a flexing interconnect (e.g. flexing interconnect300ofFIG. 5) having aligned or offset air slots of an electrical lead suspension, in accordance with one embodiment of the present invention. For example, as shown inFIGS. 4aand4b, instead of using a common slot for both read130and write120conductor pairs, each pair has a separate series of slots either aligned or offset from the other one. That is, the air slots of430aofFIG. 4aare aligned with the air slots430b, while the air slots460aare offset with the air slots460b. The aligned and offset air slots disrupt/reduce the flow of differential return currents in the ground plane802resulting in lower signal loss. Also independent, offset and unconnected air slots460aand460bin the ground plane802for each conductor pair, reduce read to write coupling and work like a shield against cross talk between adjacent signal conductor pairs and surrounding interference signals inside the hard-disk-drive111enclosure.

With reference now to step702ofFIG. 7and toFIG. 2, one embodiment provides a laminate. In one embodiment, the laminate is provided in the tail portion of the ELS (e.g., tail portion309ofFIG. 3). The laminate, according to one embodiment, has at least a signal-conductor layer, a dielectric layer and a base-metal layer. The dielectric layer resides between the signal-conductor layer and the base-metal layer.

Referring now to step704ofFIG. 7and toFIGS. 4aand4b, one embodiment supports a plurality of read traces, e.g., read traces130ofFIG. 4a, above aligned air slot pattern430bof dual aligned air slots430aand430b(or offset air slot pattern460bof dual offset air slots460aand460babove at least a tail portion309(ofFIG. 3) of an ELS127, the aligned air slot pattern430b(or offset air slot pattern460b) being formed in the base-metal layer802of the laminate in accordance with defined air gap to base-metal dimension ratio, K. The plurality of read traces are, according to one embodiment, formed of a signal-conductor layer.

With reference now to step706ofFIG. 7and toFIGS. 4aand4b, one embodiment provides a plurality of air slots (e.g., aligned air slots430aand430b, and offset air slots460aand460b) in a second formed layer of the laminate, the plurality of air slots having openings under both the first plurality of signal traces (e.g., write traces120) and the second plurality of traces (e.g., read traces130). In one embodiment, the aligned air slots (e.g., aligned air slots430aand430b) are partitioned440between the openings (e.g., aligned air slots430aand430b) under the first plurality of signal traces120and the second plurality of traces130. In one embodiment, the ELS with the plurality of air slots (e.g., aligned air slots430aand430b, and offset air slots460aand460b) supports the dielectric layer supporting the plurality of signal traces and the subsequent plurality of patterns supporting the dielectric layer supporting the subsequent plurality of traces, wherein the supporting the subsequent plurality of traces separate from said plurality of signal traces reduces signal loss and cross talk between said plurality of signal traces and said subsequent plurality of traces. In other words, in one embodiment, e.g.,FIG. 4a, the second air slot pattern430bis aligned with the first air slot pattern430awith a partition440to reduce/disrupt the read to write coupling and work like a shield against cross talk between adjacent signal conductor pairs. In another embodiment, e.g.,FIG. 4b, the second air slot pattern460ais offset from the first air slot pattern460bto reduce/disrupt the read to write coupling and work like a shield against cross talk between adjacent signal conductor pairs. The addition of the partition440or the offset of the air slots disrupt/reduce the flow of differential return currents in the ground plane802resulting in lower signal loss. Also independent, unconnected and/or offset air slots430aand430b(or460aand460b) in the ground plane802for each conductor pair, reduce read to write coupling and work like a shield against cross talk between adjacent signal conductor pairs and surrounding interference signals inside the hard-disk-drive111enclosure.

FIG. 8is a top view800of signal traces801(e.g. read or write traces), in accordance with an embodiment of the present invention, where x1 is the periodic width of the air gaps803and804, and x2 is the periodic width of the base-metal layer802. The ratio, K=x1/x2, affects characteristic impedance (Zo) of a signal trace. The ratio K, the signal trace widths, and the cross-section dimensions of the laminate layers determine the characteristic impedance of the signal traces. Therefore, the required characteristic impedance can be achieved by proper design of K, signal trace width(s), and the cross-section geometry. The period dimension, P=x1+x2, inFIG. 8can be designed to be low with respect to the electrical signals' wavelength. Also, the period P may be constant or may vary along the signal traces' path to accommodate special electrical signal shaping.

FIG. 9is a physical-electrical schematic900of the read and write traces901(read1,2and write3,4) over the dual offset air slot base-metal902, in accordance with an embodiment of the present invention. The cross talk source is the write driver,906, and the write signals propagate to the write element910through the ELS907. The read amplifier,905, receives the signal from the read element909. Here, the cross talk injection voltage (Vw) is measured across at904, and far-end cross talk voltage (Vr) is measured across at903. The relative cross talk level, Vct, is in dB units, where Vct=20*log10(Vr/Vw). The physical separation of the dual offset air slot, for the read and write traces, reduces the mutual couple terms911(Cmand Lm).

Thus, the present invention provides, in various embodiments, an electrical lead suspension having partitioned air slots. Although embodiments of the present invention are described in the context of an ELS in an information storage system, it should be understood that embodiments may apply to any device utilizing an electrical interconnect that might experience signal loss and cross talk between signal traces. For example, embodiments of the present invention may apply to rigid printed circuit boards. More specifically, embodiments of the present invention may be used in printed circuit boards that are used for high speed signal processing. Embodiments of the present invention are also suitable for use in flexing circuits, e.g., flexing circuits for digital cameras and digital camcorders. According to one embodiment, the signal traces may be replaced with power traces.