Abstract:
A method of assembly a dual stage actuated suspension includes either applying an adhesive to a microactuator motor and then B-staging, it or applying an adhesive that has already been B-staged such as in film adhesive form, then assembling it to a microactuator and then finishing the adhesive cure. The method allows greater control over how much adhesive is used, and greater control over spread of that adhesive, than traditional liquid epoxy dispense methods. Additionally, a suspension is provided that has a wrap-around electrode such that both the driving voltage and the ground, which are normally connected at different sides of a PZT, can be connected at the same side of the PZT, thus simplifying electrical connections to the PZT.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from Provisional Patent Application No. 61/709,573 filed Oct. 4, 2012, the disclosure of which is incorporated by reference as if fully set forth herein. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to the field of suspensions for hard disk drives. More particularly, this invention relates to methods of assembling suspensions using microactuators having partially cured adhesives, and methods of producing microactuator motors having wrap-around electrodes. 
     2. Description of Related Art 
     Magnetic hard disk drives and other types of spinning media drives such as optical disk drives are well known.  FIG. 1  is an oblique view of an exemplary prior art hard disk drive and suspension for which the present invention is applicable. The prior art disk drive unit  100  includes a spinning magnetic disk  101  containing a pattern of magnetic ones and zeroes on it that constitutes the data stored on the disk drive. The magnetic disk is driven by a drive motor (not shown). Disk drive unit  100  further includes a disk drive suspension  105  to which a magnetic head slider (not shown) is mounted proximate a distal end of load beam  107 . Suspension  105  is coupled to an actuator arm  103 , which in turn is coupled to a voice coil motor  112  that moves the suspension  105  arcuately in order to position the head slider over the correct data track on data disk  101 . The head slider is carried on a gimbal which allows the slider to pitch and roll so that it follows the proper data track on the disk, allowing for such variations as vibrations of the disk, inertial events such as bumping, and irregularities in the disk&#39;s surface. 
     Both single stage actuated disk drive suspensions and dual stage actuated (DSA) suspension are known. In a single stage actuated suspension, only voice coil motor  112  moves suspension  105 . 
     In a DSA suspension, as for example in U.S. Pat. No. 7,459,835 issued to Mei et al. as well as many others, in addition to voice coil motor  112  which moves the entire suspension, at least one microactuator is located on the suspension in order to effect fine movements of the magnetic head slider to keep it properly aligned over the data track on the spinning disk. The microactuator(s) provide much finer control and much higher bandwidth of the servo control loop than does the voice coil motor alone, which effects relatively coarse movements of the suspension and hence the magnetic head slider. A piezoelectric element or component, made of piezoelectric material, sometimes referred to simply as a PZT, is often used as the microactuator motor, although other types of microactuator motors are possible. In the discussion that follows, for simplicity the microactuator will be referred to simply as a “PZT,” although it will be understood that the microactuator need not be of the PZT type. 
       FIG. 2  is a top plan view of the prior art suspension  105  in  FIG. 1 . Two PZT microactuators  14  are affixed to suspension  105  on microactuator mounting shelves  18  that are formed within base plate  12 , such that the PZTs span respective gaps in base plate  12 . Microactuators  14  are affixed to mounting shelves  18  by non-conductive epoxy  16  at each end of the microactuators. The positive and negative electrical connections can be made from the PZTs to the suspension&#39;s flexible wiring trace and/or to the grounded base plate by a variety of techniques including those disclosed in commonly owned U.S. Pat. No. 7,751,153 to Kulangara et al. 
     In assembling a DSA suspension, the process typically includes the steps of: dispensing liquid adhesive such as epoxy onto the suspension and/or the PZT; positioning the PZT into place on the suspension; and curing the adhesive, typically by thermal curing, ultraviolet (“UV”) curing, or other curing methods depending on the adhesive used. DSA suspensions often include both conductive epoxies and/or non-conductive epoxies to bond the PZT to the suspension. Conductive adhesives, such as silver-containing epoxies, are well known and are commonly used. 
       FIG. 3  shows a prior technique for bonding two PZTs in a DSA suspension including the electrical connection therebetween.  FIG. 3  is not admitted as being “prior art” within the legal meaning of that term. Similarly, the processes described herein as applicable to  FIG. 3  are also not admitted as being “prior art” within the legal meaning of that term.  FIGS. 4 and 5  are cross sectional views taken along section lines C-C′ and D-D′ in  FIG. 3 , respectively, showing the details of the bonding. As best seen in  FIG. 4 , the PZT  330  has electrodes on both sides where the bottom electrode is grounded at one end by conductive epoxy  324  through gold  326  on grounded stainless steel  328  layer, and insulated at the other end by non-conductive epoxy  320 . As best seen in  FIG. 5 , the top electrode is connected to a copper electrical contact pad  316  which is part of the suspension&#39;s electrical interconnect or flexible circuit and is insulated from the stainless steel substrate  312  by insulating layer  314  such as polyimide, by conductive epoxy  322  over non-conductive epoxy  320 . Electrical contact pad  316  provides the driving voltage for PZT  330 . Non-conductive epoxy  320  is primarily responsible for the mechanical bond between PZT  330  and stainless steel substrate  312 . In general, the height of the conductive epoxy  322  for the top electrode is difficult to control, and the overall PZT attachment process requires three epoxy bonding steps, which is time consuming and costly. Also, two separate curing steps are required for the epoxy on the bottom electrode and on the top electrode. 
     There are drawbacks to the prior methods of bonding PZTs to suspensions. It can be difficult to control exactly how much epoxy is dispensed, where the adhesive ends up due to flow of the liquid adhesive, and other issues. Various solutions have been proposed that involve, for example, channels underneath the PZTs to control the flow of adhesive and to channel any excess liquid epoxy away from sensitive areas. U.S. Pat. No. 6,856,075 to Houk, for example, proposes an adhesive attachment that has one or more reliefs under or partially under or adjacent to a PZT transducer to control the flow of adhesive by limiting or influencing adhesive travel or flow and simultaneously preventing excessive adhesive fillet height adjacent the piezoelectric motor. Additionally, if the PZT is located at or near the gimbal which carries the magnetoresistive read/write head, it becomes critical to be able to predict and control the flow of adhesive because differences in adhesive flow and distribution from one part to another can adversely affect the geometries, mechanical properties, and resulting performance of the suspension. These issues are particularly pronounced when the PZT is located at a particularly sensitive part of the suspension such as near or at the gimbaled head slider. Repeatability and predictability are especially critical in that area. Still further, the presence of liquid epoxy and its dispensing equipment within the final assembly room represents both a potential source of contamination, as well as an additional and expensive manufacturing step. 
     Another drawback to the prior attachment means is the delays in assembly time required for multiple rounds of epoxy, including both conductive epoxy and non-conductive epoxy, to be dispensed and then cured.  FIG. 6 . illustrates the typical manufacturing process for PZT attachment, in which liquid epoxy is applied to the PZT, the interconnect, and/or the load beam before attaching the PZT. Conductive epoxy is dispensed at the interconnect ( 610 ), then non-conductive epoxy is dispensed at the load beam or other location for the PZT ( 612 ). The PZT is attached to the suspension ( 614 ), and the epoxy is then cured ( 616 ) in a first curing step. Next, conductive epoxy is dispensed again ( 618 ), and then cured ( 620 ) in a second curing step. 
     SUMMARY OF THE INVENTION 
     In order to address the foregoing disadvantages and other disadvantages of prior assembly processes, the present invention employs other types of adhesive than those traditionally used for DSA suspensions, and bonding and curing steps other than those traditionally used for DSA suspensions. 
     In one aspect, the invention employs adhesive films between the PZT and the suspension, and/or employs partially curing (B-staging) of a liquid or paste adhesive such as epoxy on the PZT before the PZT is placed onto the suspension component. The suspension component to which the PZT is affixed can be a base plate such as shown in  FIGS. 1 and 2  for a baseplate mounted microactuator, a flexure such as shown in  FIGS. 3-5  for a flexure mounted actuator, the suspension&#39;s load beam, the head slider itself in the case of a collocated PZT, or any other suspension component to which a microactuator motor may be mounted. After the two parts have been mated, the epoxy or other adhesive is finally cured. The curing can be thermal curing, UV curing, or other method of curing. 
     In a second aspect of the invention, the invention is of a method for producing a PZT microactuator or other electronic device having a wrap-around electrode, and of applying and using such a device. The wrap-around electrode is a conductive coating that wraps around at least part of the PZT to cover more than one face of the PZT, and thus conduct electricity to the opposite face. The wrap-around electrode simplifies both the assembly process and the final electrical connection(s) to the PZT in the completed suspensions. According to the method, a central electrode is first formed such as by sputtering on a first face of a wafer of piezoelectric material. A first side electrode on then formed on a first side or end of the wafer and over the adjacent edge, such that the first electrode extends onto the first face but is electrically not connected with, i.e., is discontinuous from, the central electrode on that face. Similarly, a second side electrode is also formed on a second side or end that is opposite the first side, with the second electrode also extending over an adjacent edge, such that the second electrode extends onto the first face but is also electrically discontinuous from the central. Conductive material is then deposited such as but sputtering on the second face of the wafer opposite the first face, with that conductive material extending to and being in electrical contact with the first and second side electrodes. The wafer now has one central electrode on the first face that covers most of the first face, and two side electrodes, with each side electrode covering not only its respective side but wrapping around that side and covering at least respective parts of the first and second faces, preferably at narrow respective strips on the first face on either side of the central electrode. The wafer is then cut in half. The result is two piezoelectric devices, each device having a wrap-around electrode such that the first face includes both electrodes. Both the drive and the ground connection can therefore both be made to the first face of the PZT, thus simplifying the electrical connections to it. 
     The invention simplifies the assembly process for a DSA suspension, and eliminates contamination sources in the sensitive final suspension assembly. 
     Exemplary embodiments of the invention will be further described below with reference to the drawings, in which like numbers refer to like parts. The drawing figures might not be to scale, and certain components may be shown in generalized or schematic form and identified by commercial designations in the interest of clarity and conciseness. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a prior art disk drive assembly having a DSA suspension. 
         FIG. 2  is a top plan view of the prior art suspension  105  in  FIG. 1 . 
         FIG. 3  is a perspective view of a prior DSA suspension to which the present invention is applicable. 
         FIG. 4  is a sectional view taken along section line C-C′ in  FIG. 3 . 
         FIG. 5  is a sectional view taken along section line D-D′ in  FIG. 3 . 
         FIG. 6  is a process flow diagram of the process used to attached the PZT to the suspension in  FIG. 3 . 
         FIG. 7  is a process flow diagram of the simplified process used to attach a PZT to a suspension according to the invention. 
         FIG. 8  is a perspective view of a DSA suspension minus the flexure gimbal assembly, according to an embodiment of the present invention that employs integrated adhesive patterns printed onto the PZT. 
         FIG. 9  is an exploded view of the suspension of  FIG. 8 . 
         FIG. 10  is a perspective view of one of the PZTs of the suspension of  FIG. 8 , showing the integrated adhesive film underneath. 
         FIG. 11  is a perspective view of a portion of a DSA suspension according to an additional embodiment of the invention, in which integrated adhesive film is used on the top surface of the PZT. 
         FIG. 12  is a perspective view of the PZT in  FIG. 11 . 
         FIG. 13  is a side cut-away view of a PZT having a wrap-around electrode according to an additional embodiment of the invention. 
         FIG. 14  is a process flow diagram for the prior epoxy dispensing and bonding steps for the PZT of  FIG. 3   
         FIG. 15  is a process flow diagram for the prior epoxy dispensing and bonding steps and for the PZT of the present invention shown in  FIG. 13 . 
         FIGS. 16A-16G  illustrate the manufacturing steps for making the PZT with wrap-around electrode shown in  FIG. 13 . 
         FIGS. 17A and 17B  are isometric views of a PZT wafer at selected steps during the manufacturing process according to the present invention. 
         FIGS. 18A-18G  show an alternative manufacturing process that could be used to produce the PZT of  FIG. 13 . 
         FIG. 19  is a perspective view of a PZT with adhesive being applied thereto according to the invention. 
         FIG. 20  is a top perspective view of the PZT of  FIG. 19  illustrating the adhesives thereon being B-staged. 
         FIG. 21  is a side cutaway view of the PZT of  FIG. 20  after it has been applied to a suspension. 
         FIG. 22  is a side cutaway view of the PZT having a wrap-around electrode after it has been applied to a suspension. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A first aspect of the invention is the use of adhesive film to attach the PZT to the suspension.  FIG. 7  illustrates the method. Conductive epoxy is dispensed at the interconnect ( 710 ). The PZT having the integrated adhesive film or other B-staged adhesive is then attached to the suspension ( 712 ), and the adhesive is then cured ( 714 ). Conductive epoxy is then dispensed at ( 716 ) and cured ( 718 ). The step of epoxy dispensing on the load beam is eliminated by using a PZT with integrated adhesive film. PZT with integrated adhesive film can be manufactured with either laminated adhesive film on it at the PZT wafer level or by printing or by a wafer backside coating process as used in the semiconductor industry. Because the adhesive film is attached to the PZT at the wafer level before dicing into individual PZT dies, process simplification and cost savings can be achieved. Also, tight control of the adhesive thickness can be achieved. As shown in  FIG. 7  the use of a PZT with integrated adhesive also simplifies the process when compared to  FIG. 6 . The step of non-conductive epoxy dispensing at the load beam is eliminated using the method of the invention. 
     A suspension design that facilitates the use of integrated adhesive film is shown in  FIGS. 8-10 .  FIG. 8  is a perspective view of a DSA suspension, less the flexure gimbal assembly for clarity of illustration, according to an embodiment of the present invention that employs integrated adhesive film or patterns printed onto the PZT. PZTs  830  are affixed to the suspension component to which it is mounted, in this case to baseplate  812 . Actuation of the PZTs moves load beam  820  such that the head slider which is located at the distal end of the load beam moves radially. 
       FIG. 9  is an exploded view of the suspension of  FIG. 8 . 
       FIG. 10  is a perspective view of one of the PZTs  830  of suspension  810  of  FIG. 8 , showing the integrated adhesive film or printed adhesive  834 ,  836  underneath. In this embodiment, the integrated adhesive films  834 ,  836  located at both ends of PZT  830  are formed by applying adhesive film or printing adhesive patterns on the PZT wafers before dicing and singulation into individual PZT pieces. The exposed PZT surface between the adhesives will allow for electrical connection with liquid epoxy to the suspensions&#39;s electrical circuit. 
       FIG. 11  is perspective view of a portion of a DSA suspension according to an additional embodiment of the invention, in which integrated adhesive film is used on the top surface of PZTs  1130  in order to bond the PZTs to recessed portions of baseplate  1112 . 
       FIG. 12  is a perspective view of the PZT in  FIG. 11 . In this design, the integrated adhesive film or printed adhesive  1134  is located at the top surface of the PZT. The integrated adhesive film covers the entire top surface, or substantially the entire top surface, and thus no patterning of the adhesive is required. Also, conductive adhesive film can be used in this design, such that the grounding through the base plate can be achieved once the PZT is attached to the base plate. This will further eliminate the required step of grounding the PZT to the baseplate with conductive liquid epoxy as shown in  FIG. 6 . 
     The adhesive film used can be either conductive or non-conductive, depending on whether an electrically conductive connection to the suspension or the interconnect circuit is desired, or a non-conductive connection to the suspension. Film adhesives are generally “preformed” or “B-staged,” and are available in rolls, sheets, or die-cut shapes. 
     B-Staged Epoxy 
     In a slightly different embodiment, instead of applying adhesive film to the PZT and/or to the suspension, adhesive is applied to the PZT and is B-staged before final assembly. 
     The term “B-staged” or “B-staging” as used herein means, after a flowable adhesive has been dispensed, partially hardening the adhesive so that its flow rate is substantially reduced to the point that it no longer flows freely as a liquid, but is not so hard such that it is no longer available for effectively adhering to another surface. B-staging involves temporarily exposing the adhesive to an environment which causes accelerated hardening of the adhesive, then removing the adhesive from that environment such that the hardening rate slows down considerably so that the adhesive does not substantially harden during assembly. The removal of the PZT from that increased hardening environment can include simply removing the hardening accelerant from the environment. B-staging can cure or otherwise harden the adhesive to a degree such that the adhesive is no longer tacky. One method of B-staging is to partially cure a cross-linking polymer such as epoxy, such as by applying heat and/or UV, such that the epoxy achieves less than 10% cross-linking, then removing the curing source. For epoxies that are B-staged using heat, the epoxy may be immediately quenched down to a lower temperature at which cross-linking is negligible, i.e, at which the epoxy effectively ceases to harden, in order to stop the cross-linking process. For epoxies that are B-staged using UV, removing the PZT from the increased hardening environment can mean simply turning off the UV curing lamps. 
     With some adhesives, the adhesive may be mixed into a solvent to form a slurry, the solvent being one that evaporates at a lower temperature than which cross-linking begins to occur significantly. The adhesive may be a printable paste that is applied to the PZT. After dispensing, the adhesive is exposed to a specified thermal regime designed to evolve a majority of the solvent from the material without significantly advancing resin cross-linking. The result is an epoxy or other adhesive that no longer flows, but that is still available for adhering to another surface with the full or nearly full adherent strength of the epoxy. 
     B-staging an adhesive permits the adhesive and substrate construction to be “staged,” or held for a period of time prior to the bonding and curing, without forfeiting performance. A secondary thermal cure cycle yields fully crosslinked, void-free bonds. As used herein, the term “fully crosslinked” means at least 90% crosslinked. 
     The adhesive may take the form of a solid, thermosetting paste. The adhesive may be a printable paste that is printed by any known printing techniques that are suitable for use with adhesive, including screen printing, stencil printing, ink jet printing, spraying, stamping, and others. An advantage of using such printing techniques is that the adhesive can be dispensed in very fine and precise patterns onto the PZT, which helps to achieve control and repeatability of the adhesive&#39;s total mass and distribution within the finished suspension. One commercially available silver-filled conductive epoxy that is suitable for fluid jetting, screen printing, and stamping is EPO-TEK® H20E by Epoxy Technology, Inc. of Billerica, Mass. 
     A UV B-stage adhesive can be used. Such an adhesive is dispensed, then irradiated with UV energy in order to B-stage it. B-staging immediately after printing “freezes” the adhesives in position, which helps to precisely control any spread of the liquid epoxy. Unlike thermal staging, irradiating with UV energy eliminates the danger of advancing the thermoset reaction of the adhesive. UV B-staging can occur in seconds, while the thermal alternative can take an order of magnitude longer for the process. 
     Liquid epoxy or other adhesive may be first dispensed onto the PZT and/or onto the suspension, and then the epoxy is B-staged to the point that its flow is reduced to a negligible amount. The parts can then be assembled in the final, clean room assembly area for the disk drives, and the adhesive then fully cured either by heat or by UV. Such techniques have been used, or have been proposed to be used, in the integrated circuit (IC) packaging field under the broad term of wafer backside coating (WBC). Wafer backside coating techniques using both conductive and non-conductive adhesives can be adapted from die attach processes used in IC packaging to PZT attach processes for suspensions. Inkjet printing of polymers, both conductive and non-conductive, has also been proposed. Such inkjet printing techniques can be adapted for use in printing adhesives onto the PZTs for bonding those PZTs to suspensions. 
     It is anticipated that one method of production will be to begin with a wafer of PZT material, either applying already B-staged adhesive to it such as in adhesive film form or applying adhesive to it then B-staging the adhesive, then dicing the wafer into individual PZT microactuator motors. Pick-and-place machinery will be used to pick up the individual PZT die with the B-staged adhesive on it, assemble the PZT die to the suspension, and dwell there for the appropriate time and under the appropriate temperature and pressure conditions in order to fully cure the adhesive, and thus fully adhere the PZT to the suspension. 
     Wrap-Around Electrode 
     In another aspect, the invention is of a method of producing a piezoelectric microactuator or other electronic device having a wrap-around electrode, such that both the drive voltage and ground electrodes are located and accessible on the same side of the device. 
       FIG. 13  is a side cut-away view of a PZT according to an additional aspect of the invention. PZT  1330  has a bottom electrode  1334  and a “wrap-around” electrode  1336  that enables simplified electrical connections to the PZT. In this embodiment, the top electrode  1336  is wrapped around the PZT onto one end of the bottom PZT surface. The driving voltage is thus applied to the bottom surface of the PZT on a first end thereof, and the electrical ground is connected to the bottom surface on the opposite end. Thus, both electrodes  1334 ,  1336  can be electrically connected by conductive epoxy  1340 ,  1342 , respectively, on the same surface or side of the PZT. This reduces the number of epoxy bonding steps to two steps and eliminates the difficult to control epoxy height tolerance on the top PZT surface. Also, only a single curing step is needed. 
       FIG. 14  is a flow diagram of a manufacturing process using prior epoxy dispensing and bonding steps for attaching the PZT to its suspension as shown in  FIG. 3 . Conductive epoxy is first dispensed for grounding ( 1410 ). Non-conductive epoxy is then dispensed for insulation ( 1412 ). The PZT is then attached to the suspension, at step  1414 . The epoxies are then cured ( 1416 ). A second epoxy dispensing step is then performed ( 1418 ). Finally, that last-dispensed epoxy is cured ( 1420 ). The process required two separate curing steps. 
       FIG. 15  is a flow diagram of a manufacturing process according to the present invention for bonding the PZT to its suspension as shown in  FIG. 13 . Conductive epoxy is dispensed for grounding ( 1510 ). Conductive epoxy is then dispensed for the signal or driving voltage for the PZT ( 1512 ). The PZT is then attached to the suspension ( 1514 ). Finally, the assembly is cured ( 1516 ). The figures illustrate the simplification that is obtained by using a PZT with a wrap-around electrode according to the invention. 
       FIGS. 19-21  illustrate the preparation and placement of a PZT having B-staged adhesive according to the invention.  FIG. 19  is a perspective view of a PZT  1930  with adhesive  1920 ,  1924  being applied to what will be the bottom surface of PZT  1930 . In general, the adhesive can be applied by any one of a number of known techniques including screen printing, stencil printing, ink jet printing, spraying, application as a film, and others. In general, any patterns desired of a combination of conductive adhesive and/or non-conductive adhesive may be applied to PZT  1930 . In the illustrative embodiment shown, the adhesive is sprayed by ink jet heads  1910 ,  1911 , to produce one strip of conductive epoxy  1924 , and one strip of non-conductive epoxy  1920 . The two strips can be of different thicknesses, with one strip being thicker than the other. 
       FIG. 20  is a top perspective view of PZT  1930  with the adhesives being B-staged. In the figure, the epoxy strips  1920 ,  1924  are being UV B-staged. In general, adhesives  1920 ,  1924  can be B-staged using any known technique including thermal B-staging and UV B-staging. Furthermore, the two strips of adhesive  1920 ,  1924  can be B-staged to different extents, leaving one strip more cured or hardened than the other. For UV curing, masks or screens can be used in order to irradiate one strip more than the other. 
       FIG. 21  is a side cutaway view of PZT  1930  after it has been applied to a suspension.  FIG. 21  is analogous to  FIG. 3  and illustrates how the present invention can simplify the prior process. After PZT  1930  has been positioned, pressure is applied to at least the left side of the PZT as seen in the figure in order to squeeze non-conductive epoxy  1920  so that it flows into the gap between the PZT and polyimide layer  314 , and covers the previously exposed stainless steel  312  adjacent the PZT. The pressure could be applied by mechanically pressing on the PZT. Alternatively, depending on how much hardening occurred during the B-staging process, the weight of the PZT itself may provide sufficient force and pressure to squeeze non-conductive epoxy  1920  into that gap. After the PZT is positioned, and pressed down if necessary, conductive epoxy  322  is applied so as to bridge the gap between the metallized top surface of the PZT, which defines the drive electrode, and copper contact pad  316  which supplies the drive voltage to the PZT. All of the epoxy in the assembly is then cured at the same time in a single curing step. This process eliminates the need for a second curing step as was required for the assembly and process of  FIGS. 3-6 . 
       FIG. 21  represents only one of a number of possible different types of electrical connections and electrical connection methods for providing the PZT driving voltage and ground to the PZT. Many other connection types and methods are possible, such as disclosed in U.S. Pat. No. 8,189,301 to Schreiber, and U.S. Pat. No. 7,751,153 to Kulangara. The present invention is applicable in suspensions that employ various types of electrical connections to the PZTs. 
     As an alternative to the bonding structure shown in  FIG. 21 , PZT  1930  could be extended farther to the left in the figure, such that the PZT is bonded directly to copper contact pad  316 . 
       FIGS. 16A-16G  illustrate the manufacturing steps for making the PZT with wrap-around electrode shown in  FIG. 13 . First, a PZT block or wafer  1630  is placed onto a transfer tape  1602 , with PZT bottom surface  1631  facing downward ( FIG. 16A ). Next, an appropriate mask is placed over the top surface of the PZT wafer, and a metallization layer  1604  such as aluminum metallization is sputtered onto the top surface ( FIG. 16B ). The mask leaves strips  1606  of PZT surface not metallized. Kerf  1608  is then cut into the PZT wafer to separate a first portion, which will be referred to as a PZT precursor  1632 , from the rest of the wafer ( FIG. 16C ). A second mask  1612  is placed over PZT precursor  1632 , and additional metallization  1605  is sputtered into the kerfs onto the sides of PZT precursors  1632  within kerfs  1608  in order to make those sides electrically conductive and electrically continuous with the metallizations on the top surface of the PZT adjacent the kerfs ( FIG. 16D ). 
     Next, the PZT precursor  1632  is flipped over and preferably placed onto a second transfer tape in order to expose what had been the bottom surface  1631  of the PZT precursor ( FIG. 16E ). That bottom surface  1631  will continue to be referred to as the bottom surface even though it is now facing upward. A metallization layer  1614  is then sputtered onto the entire bottom surface  1631  of the PZT precursor ( FIG. 16F ). Finally, a new cut  1616  is made into the PZT, separating the first PZT generally in half and defining what will be referred to as first PZT  1634  and second PZT  1636  ( FIG. 16G ). 
     The result of this process is two PZTs  1634 ,  1636  each of which has the same structure. A narrow stripe of metallization  1650  on the first PZT&#39;s top surface  1633  and near its end, defines a first electrode. The first electrode  1650  electrically wraps around via the metallized side surface  1605  of the PZT to the bottom surface  1631  of the PZT and to the metallization  1604  that generally covers bottom surface  1631 . A second electrode  1652  on the top surface  1633  of the first PZT covers most, but not all, of the PZT top surface  1633 . In this way, a first PZT has been constructed whose first electrode  1650  is located on the same surface of the first PZT as the second electrode  1652 . Generally speaking, the first electrode can be the electrode at which the PZT drive voltage is applied with the second electrode being the electrode at which the PZT is grounded, or vice versa. The second PZT is substantially identical to the first PZT. 
       FIGS. 17A and 17B  are isometric views of a PZT wafer at selected steps during the manufacturing process according to the present invention.  FIG. 17A  is an isometric view of the PZT strips  1634 ,  1636  at the end of the process in  FIG. 16 . Now, the PZT is ready for poling; the final dicing operation can be performed afterward to create the individual PZTs as shown in  FIG. 17B . The result is a first row of PZTs  1638  and a second row of PZTs  1640 , both having wrap-around electrodes. 
       FIGS. 18A-18G  illustrate alternative manufacturing steps for making the PZT having a wrap-around electrode. The PZT wafer  1830  is placed onto a transfer tape  1802  with its bottom surface  1831  facing downward ( FIG. 18A ). Kerfs  1808  are then cut into PZT  1830  to separate a first portion, which will be referred to as a PZT precursor  1832 , from the rest of the wafer ( FIG. 18B ). The kerfs  1808  on either side of PZT precursor  1832  are then filled with a conductive and hardenable material  1820 , such as conductive epoxy paste containing copper, silver, or other conductive material or particles ( FIG. 18C ). Silver epoxy is one such commonly used material, and will be used as an example. Silver epoxy  1820  is then allowed to harden. Next, an appropriate mask is placed over the top surface of PZT precursor  1832 , and a metallization layer  1804  such as aluminum metallization is sputtered onto the top surface ( FIG. 18D ). The mask prevents metallization along two narrow strips  1806 ,  1807  on the top surface of the PZT precursor near the ends thereof. The result is that the PZT precursor  1832  has two relatively narrow stripes of metallization  1842 ,  1844  on the top surface of the PZT precursor near either end thereof, and a large metallization area  1846  generally centered on the PZT precursor. At this point in the process, each stripe of metallization  1842 ,  1844  near an end of the PZT precursor is electrically connected to the silver epoxy  1820  on the end of the PZT precursor to which that stripe is adjacent, and each of the two stripes of metallization  1842 ,  1844  and the large metallized region  1846  in the center are all electrically isolated or electrically discontinuous from each other. 
     Next, the PZT precursor is flipped over and preferably placed onto a second transfer tape in order to expose what had been the bottom surface  1831  of the PZT precursor ( FIG. 18E ). That bottom surface  1831  will continue to be referred to as the bottom surface even though it is now facing upward. A metallization layer  1814  is then sputtered onto the entire bottom surface of the PZT precursor ( FIG. 18F ). Finally, a new cut  1818  is made into the PZT precursor, cutting the PZT precursor generally in half, and another cut  1816  is made through the silver epoxy, thereby separating the PZT precursor in half and defining what will be referred to as first and second PZTs ( FIG. 18G ). The cut  1816  is within kerf  1808  and is narrower than kerf  1808  so as to leave the side of the PZT precursor covered with conductive silver epoxy  1820 , and thus serves as an electrical bridge or wrap-around from the PZT&#39;s top surface to its bottom surface. 
     The result of this process is two PZTs each of which has the same structure. A narrow stripe of metallization  1844  on the first PZT&#39;s top surface  1833  and near its end, defines a first electrode. The first electrode  1844  electrically wraps around via the silver epoxy  1820  to bottom surface  1831  of the PZT and to the metallization that generally covers bottom surface  1831 . A second electrode  1852  on the top surface  1833  of the first PZT covers most, but not all, of the PZT top surface  1833 . In this way, a first PZT has been constructed whose first electrode  1844  is located on the same surface of the first PZT as the opposite electrode  1852 . The second PZT is substantially identical to the first PZT. 
       FIG. 22  is a side cutaway view of the PZT having a wrap-around electrode such as the PZTs of either  FIG. 16G  or  FIG. 18G , after it has been applied to a suspension. PZT  1830  has a first and wrap-around electrode  1844  which serves as the drive or positive electrode, and a second electrode  1852  which serves as the ground electrode. Drive electrode  1844  is bonded to copper contact pad  316  on polyimide layer  314  over stainless steel substrate  312 , via conductive epoxy  1924 . Ground electrode  1852  is grounded to stainless steel substrate  328  via gold bond pad  326  and conductive epoxy  1928 . Strips of conductive epoxy  1924  and  1928  can be B-staged epoxies as discussed above, with the epoxies fully cured after the parts have been assembled as shown in the figure. This embodiment completely eliminates the need to dispense any epoxy within the suspension assembly room, and eliminates any liquid or paste epoxy from that room, and thereby helps to keep that environment free from contamination. 
     It will be understood that the terms “generally,” “approximately,” “about,” and “substantially,” as used within the specification and the claims herein allow for a certain amount of variation from any exact dimensions, measurements, and arrangements, and that those terms should be understood within the context of the description and operation of the invention as disclosed herein. 
     It will further be understood that terms such as “top,” “bottom,” “above,” and “below” as used within the specification and the claims herein are terms of convenience that denote the spatial relationships of parts relative to each other rather than to any specific spatial or gravitational orientation. Thus, the terms are intended to encompass an assembly of component parts regardless of whether the assembly is oriented in the particular orientation shown in the drawings and described in the specification, upside down from that orientation, or any other rotational variation. 
     All features disclosed in the specification, including the claims, abstract, and drawings, and all the steps in any method or process disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. Each feature disclosed in the specification, including the claims, abstract, and drawings, can be replaced by alternative features serving the same, equivalent, or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. 
     It will be appreciated that the term “present invention” as used herein should not be construed to mean that only a single invention having a single essential element or group of elements is presented. Similarly, it will also be appreciated that the term “present invention” encompasses a number of separate innovations which can each be considered separate inventions. Although the present invention has thus been described in detail with regard to the preferred embodiments and drawings thereof, it should be apparent to those skilled in the art that various adaptations and modifications of the present invention may be accomplished without departing from the spirit and the scope of the invention. For example, instead of selectively applying and partially curing adhesive on the PZT, adhesively could be selectively applied and partially cured on other suspension components such as the flexure. Accordingly, it is to be understood that the detailed description and the accompanying drawings as set forth hereinabove are not intended to limit the breadth of the present invention.