Patent Publication Number: US-2009237841-A1

Title: Magnetic head and magnetic recording device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority of each of prior Japanese Patent Application No. 2008-72032, filed on Mar. 19, 2008, and prior Japanese Patent Application No. 2008-332030, filed on Dec. 26, 2008, the entire contents of which are incorporated herein by reference. 
     FIELD 
     This invention relates to a magnetic head and a magnetic recording device. 
     BACKGROUND 
     A magnetic recording device has a magnetic head which accesses data stored in a magnetic disc, and is placed at a front end of a suspension. The magnetic head includes a slider carrying a head element. When the slider is loaded on a desired track of the magnetic disc in response to the movement of an arm of the suspension, the magnetic head reads and writes data from and in the magnetic disc. 
     Recently, as the capacity of a magnetic disc is increased, a clearance between a magnetic head and the magnetic disc, i.e. a floating distance of a head element from the magnetic disc, becomes very small. Therefore, it is important to control the floating distance of the magnetic head. At present, there has been proposed a method in which a micro heater in the shape of a thin film is attached to the head element, and a sticking amount of the head element is controlled by thermal expansion of the micro heater which is electrically turned on and is heated. However, it takes time to control the head element by heating the micro heater. Although it is possible to control the floating distance which varies in response to variations caused by fabricating processes or barometric pressure, it is very difficult to actively and quickly control the floating distance. 
     In order to improve the controllability of the floating distance, the use of a piezoelectric micro actuator is now on trial. With a magnetic head including an existing piezoelectric micro actuator, a piezoelectric device is attached to a slider, under which a reading element and a recording element are disposed. When the piezoelectric device perpendicularly expands and contracts in response to an intensity of a read signal read by the reading element, a distance between the reading element and the magnetic disc will be controlled. 
     Up to now, in a popular magnet recording device, a slider is disposed in parallel to a recording surface of a magnetic disc, and piezoelectric devices, and a recording element, reading element are sequentially positioned. In such a magnetic recording device, the piezoelectric device perpendicularly expands and contracts with respect to a recording surface of the magnetic disc when a voltage is applied. A distance between the disc and the recording and reading elements is regulated because these elements are attached to the piezoelectric device and are displaced in response to the expansion and contraction of the piezoelectric device. 
     Further, there is known a magnetic recording device in which an actuator made of piezoelectric ceramics is provided on an upper surface of a suspension base to which a magnetic head is attached. A sensor detects deformation of the suspension in response to the displacement of the magnetic head, returns the suspension to the normal state, and makes the floating distance of the magnetic head constant. 
     SUMMARY 
     According to one aspect of the invention, there is provided a magnetic head which includes a head element recording and reading data on and from a recording medium, a slider having an air bearing surface facing the recording medium, and having the head element forming surface which the head element being present on, and a piezoelectric device attached above the head element forming surface and the head element, and configured to displace a part of the head forming surface in a direction perpendicular to the air bearing surface. 
     The object and advantage of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a magnetic disc unit including a magnetic head according to embodiments of the invention; 
         FIG. 2  is a partly exploded side elevation of the magnetic head in a first embodiment of the invention; 
         FIG. 3  is a cross sectional view of a head element constituting the magnetic head in the first embodiment; 
         FIG. 4  is a perspective view of the magnetic head in the first embodiment; 
         FIG. 5  is a perspective view illustrating a structure of a laminated piezoelectric device in the magnetic head of the first embodiment; 
         FIG. 6  is a view illustrating a bonding structure of the laminated piezoelectric device of the magnetic head of the first embodiment; 
         FIGS. 7A and 7B  are perspective views illustrating how to make the magnetic head in a first step in the first embodiment; 
         FIGS. 8A and 8B  are perspective views illustrating how to make the magnetic head in a second step in the first embodiment; 
         FIGS. 9A to 9D  are perspective views illustrating how to make laminated piezoelectric devices constituting the magnetic head in the first embodiment; 
         FIG. 10  is a perspective view illustrating a state in which a groove is made on an air bearing surface of the magnetic head in the first embodiment; 
         FIG. 11  is a partly exploded side elevation of the magnetic head illustrated in  FIG. 10 ; 
         FIG. 12  illustrates a groove in a bar constituting the magnetic head in the first embodiment; 
         FIG. 13  is a perspective view of another laminated piezoelectric device on the magnetic head in the first embodiment; 
         FIG. 14  is a perspective view of a pair of grooves interleaving the laminated piezoelectric device of the magnetic head in the first embodiment; 
         FIG. 15  is a perspective view of a further piezoelectric device which is made in the magnetic head in the first embodiment; 
         FIG. 16  is a perspective view of a magnetic head according to a second embodiment of the invention; 
         FIG. 17  is a partly exploded side elevation of the magnetic head of  FIG. 16 ; 
         FIGS. 18A to 18D  are perspective views illustrating processes for fabricating laminated piezoelectric devices of the magnetic heads in the second embodiment; 
         FIG. 19  is a perspective view of a groove formed in an air bearing surface of the piezoelectric device in the second embodiment; 
         FIG. 20  is a partly exploded side elevation of the magnetic head illustrated in  FIG. 19 ; 
         FIG. 21  illustrates the magnetic head including a small laminated piezoelectric device; 
         FIG. 22  is a perspective view of a pair of grooves interleaving the laminated piezoelectric device of the magnetic head in the second embodiment; 
         FIG. 23  is a perspective view illustrating a further piezoelectric device of the magnetic head of the second embodiment; 
         FIGS. 24A and 24B  illustrate how to bond the piezoelectric device (illustrated in  FIG. 23 ) to the magnetic head; 
         FIG. 25  is a perspective view of a laminated piezoelectric device in a magnetic head according to a third embodiment; 
         FIGS. 26A and 26B  are perspective views illustrating how to make the laminated piezoelectric devices illustrated in  FIG. 25 ; 
         FIGS. 27A and 27B  illustrate how the laminated piezoelectric device is bonded to the magnetic head; 
         FIG. 28  is a front elevation of a magnetic head according to a fourth embodiment of the invention; 
         FIGS. 29A to 29D  are perspective views illustrating how to make the magnetic head in a first step in the fourth embodiment; 
         FIGS. 30A to 30C  are perspective views illustrating how to make the magnetic head in a second step in the fourth embodiment; 
         FIGS. 31A and 31B  are perspective views illustrating magnetic head making processes in the fourth embodiment; 
         FIG. 32  is a partly exploded side elevation of a magnetic head according to a fifth embodiment; 
         FIGS. 33A and 33B  are side elevations illustrating a first magnetic head making process in the fifth embodiment; 
         FIGS. 34A to 34D  are side elevations illustrating a second magnetic head making process in the fifth embodiment; 
         FIG. 35  is a partly exploded view of a part of a magnetic head of a sixth embodiment of the invention; 
         FIGS. 36A and 36B  are side elevations illustrating how the magnetic heads are made in the sixth embodiment; and 
         FIGS. 37A to 37D  are side elevations illustrating magnetic head making processes in the sixth embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     In the related art, if the piezoelectric device is provided between the slider and reading and recording elements, the manufacturing process is complicated and becomes very expensive. Further, the structure in which the actuator is attached to the suspension does not require extensive modifications in the fabricating process. However, since the magnetic head is displaced by deforming the suspension, the actuator is not able to have a high resonance frequency. Therefore, it is very difficult to actively control the displacement of the magnetic head. Still further, minute control of the tip of the magnetic head is very difficult because the distance between the actuator and the magnetic head is relatively long. 
     On the contrary, in the magnetic recording device of the present invention, the tip of the magnetic head is displaced by the piezoelectric device attached above the area including the head element. This means that the part to be displaced by the piezoelectric device is small, and the response time of the magnetic head can be shortened. 
     Further, the piezoelectric device is attached after the head element is made and before the wafer is cut, which does not require extensive modifications of the magnetic head fabricating process. 
     The invention will be described hereinafter with reference to embodiments illustrated in the drawings. In the drawings, like or corresponding parts are denoted by like or corresponding reference numerals. 
     First Embodiment 
       FIG. 1  illustrates a magnetic recording device  1  with a cover of an enclosure  2  being removed. 
     In the magnetic recording device  1 , a magnetic disc  3  functions as a magnetic recording medium, is housed in the center of the enclosure  2 , and is rotated by a spindle motor. The enclosure  2  seals the interior of the magnetic recording device  1 . Further, a carriage arm  4  is housed in the enclosure  2 , and is rotatable around an axis  5 . The carriage arm  4  includes a suspension  6 , which has a magnetic head  10  positioned at an end thereof. 
     When the axis  5  is rotated by a control unit  8  housed in the enclosure  2 , the carriage arm  4  rotates and moves above the magnetic disc  3 . This enables the magnetic head  10  to move in a width direction of tracks, and is loaded onto a desired track. 
     Magnetic recording devices according to other embodiments are structured similarly to the magnetic recording device  1  of the first embodiment except for the magnetic head  10 . 
     Referring to  FIG. 2 , the magnetic head  10  has a slider  11  which is attached to an end of a suspension  6  and on a surface opposite to the magnetic disc  3 . The slider  11  is made of a nonmagnetic material such as Al 2 O 3 —TiC. The slider  11  is provided with a head element forming surface  11 A at its end. A head element  12  is formed on the head element forming surface  11 A, and records and reads data on and from the magnetic disc  3 . The bottom of the slider  11  serves as an air bearing surface  11 B. 
     The head element  12  has a structure which is applied to the perpendicular magnetic recording technology, for instance. Specifically, a magnetic reading head  19  is made on the slider  11  via an insulating layer  18  made of alumina (Al 2 O 3 ). A magnetic recording head  20  is made over the magnetic reading head  19  via an insulation-isolation layer  22  and a nonmagnetic isolation layer  23 . 
     The slider  11  of no magnetism is manufactured by forming the head element  12  on a substrate, and by cutting, polishing and shaping the substrate. Thereafter, the head element  12  including the magnetic reading head  19  and the magnetic recording head  20  is positioned to face with a recording surface of the magnetic disc  3 . 
     On the slider  11 , the magnetic reading head  19  is placed at a leading side of the magnetic disc  3  while the magnetic recording head  20  is placed at a trailing side of the magnetic disc  3 . 
     The magnetic reading head  19  includes a lower magnetic shield layer  25 , an magnetic gap layer  26  and an upper magnetic shield layer  37 , all of which are laid one over another. A reading element  28  is present in the magnetic gap layer  26 . 
     The lower and upper magnetic shield layers  25  and  37  are made of magnetic materials such as FeNi alloy layers. The magnetic gap layer  26  is made of an insulating material such as alumina. The reading element  28  is connected to a pair of electrodes (not illustrated) which are present in the magnetic gap layer  26 . Sometimes, the lower and upper magnetic shield layers  25  and  37  are used as a pair of electrodes depending upon a device structure of the reading element  28 . 
     An MR (Magneto Resistance) effect element, a GMR (Giant Magneto Resistance) effect element, or a TMR (Tunneling Magneto Resistance) effect element is used as the reading element  28 . 
     The reading element  28  is positioned on the air bearing surface  11 B of the head elements  12 , and faces with the magnetic disc  3 , i.e. at an area facing with the recording medium. 
     The magnetic recording head  20  has a main magnetic pole  31  on a nonmagnetic isolation layer  23 . A nonmagnetic insulation layer  32  is provided around the main magnetic pole  31 , and is magnetically isolated from the main magnetic pole  31 . A nonmagnetic gap layer  33  is formed over the main magnetic pole  31  and nonmagnetic insulation layer  32 . A lower insulation layer  34   a  and an energizing coil  35  are made on the nonmagnetic gap layer  33 , and a coated insulation layer  34   b  extends over the energizing coil  35 . A return yoke  36  made of a magnetic layer is formed above a trailing side of the coated insulation layer  34   b . A trailing side magnetic shield layer  37  is provided at an end of the return yoke  36  near the recording medium, and is connected to the return yoke  36 . 
     Referring to  FIGS. 2 and 4 , an alumina layer  40  serving as a cover insulation film is provided on the head element forming surface  11 A of the slider  11 , and extends over the head element  12 . A laminated piezoelectric device  41  is bonded to the head forming surface  11 A via the alumina layer  40 , and functions as an actuator. 
     The alumina layer  40  is used to smooth the head element forming surface  11 A to which the laminated piezoelectric device (hereinafter referred to as “piezoelectric device”)  41  is bonded. The alumina layer  40  is preferably made of a nonmagnetic material. Alternatively, the alumina layer  40  may be an adhesive. 
     As illustrated in  FIGS. 4 and 5 , the piezoelectric device  41  includes a piezoelectric layer  42 , and a plurality of electrodes provided in and on the piezoelectric layer  42 . The piezoelectric layer  42  is perpendicularly stacked, i.e. are approximately in parallel to the air bearing surface  11 B. 
     The piezoelectric device  41  includes a pair of surface electrode  43 A and  43 B on its front and rear surfaces; and first and second inner electrodes  44 A and  44 B placed between the piezoelectric layers  42 . Further, the piezoelectric device  41  includes first and second terminal electrodes  45 A and  45 B which are connected to an end of the electrode  43 A,  43 B,  44 A or  44 B. The first and second inner electrodes  44 A and  44 B are alternately placed with predetermined spaces maintained in the laminated direction of the piezoelectric layers  42 . 
     The first and second terminal electrodes  45 A and  45 B are provided around the piezoelectric layers  42 . Specifically, the first terminal electrode  45 A is connected to upper ends of the surface electrodes  43 A and  43 B and the first inner electrode  44 A. The second terminal electrode  45 B is connected to an upper end of the second inner electrode  44 B and sticks out of the front and rear ends of the piezoelectric layers  42 . 
     Further, the surface electrodes  43 A and  43 B and the first inner electrode  44 A have cuts, which prevent them from being short circuited by the second terminal electrode  45 B. In short, the surface electrodes  43 A and  43 B are connected only to the first terminal electrode  45 A. The second inner electrode  44 B has a cut, which prevents it from being short circuited by the first terminal electrode  45 A. The second inner electrode  44 B is electrically connected only to the second terminal electrode  45 B. 
     When the piezoelectric device  41  to a power source is connecting, a positive (+) pole of the power source is connected to either the terminal electrode  45 A or the surface electrode  43 A (or  43 B). Further, a negative (−) pole of the power source is connected to the second terminal electrode  45 B. In this state, the surface electrodes  43 A and  43 B and the first center inner electrode  44 A have a positive potential while the two second inner electrodes  44 B interleaved by the foregoing electrodes have a negative potential. The number of the piezoelectric layers of the piezoelectric device  41  and the number of inner electrodes are not limited to those illustrated in  FIG. 5 . Further, the surface electrodes  43 A and  43 B may be positioned on either the front or rear surface of the piezoelectric device  41 . 
     The piezoelectric layers  42  are made of piezoelectric ceramics (including electrostrictive materials) ordinarily used for piezoelectric devices. For instance, the following ceramics are usable: Pb-group perovskite ceramics such as Pb (Ni, Nb)O 3 —PbZrO 3 —PbTiO 3 -group (PNN-PZT group) and Pb (Mg, Nb)O 3 —PbZrO 3 —PbTiO 3  group (PNN-PZT group); and non-Pb group piezoelectric ceramics such as Ba group or Bi group. 
     The first and second inner electrodes  44 A and  44 B are preferably made of Pt, Pd, Au, Ag, Cu or Ni, or alloys of the foregoing metals which are not mixed up with ceramics when they are calcined together. The surface electrodes  43 A and  43 B, and the first and second terminal electrodes  45 A and  45 B are preferably made of metals such as Au, Ag, Pt, Ni, Cu and Sn. The piezoelectric device  41  may be in the shape of a simple rectangle, and can be manufactured or procured at a low cost. 
     Referring to  FIG. 6 , metal joints  51  and a plurality of electrode pads  52  are provided on the alumina layer  40  covering the head element forming surface  12  of the slider  11 , and electrically and reliably connect and bond the piezoelectric device  41  to the slider  11 . 
     The metal joints  51  extend over an area substantially facing with the head elements  12 , have conductivity, and are approximately in the shape of the surface electrode  43 A. 
     The two center electrode pads  52  are used to supply power to the piezoelectric device  41  while the remaining electrode pads  52  are used for electrically connecting to read and write terminals of the head element  12 . 
     One of the center electrode pads  52  is integrated to one metal joint  51  which is under the center pad  52 , but may be a single member and be connected to the metal joints  51  later. The remaining electrode pads  52  are electrically connected to electrode terminals of the head element  12  via openings (not illustrated) in the alumina layer  40 . The electrode pads  52  are connected in the similar manner in the following embodiments. 
     To the electrode pads  52  are connected to a readout wire and a write wiring of the head element  12  and wirings for activating the piezoelectric device  41 . Those wirings extend on the bottom surface of the suspension  6 , and are connected to the control unit  8 . 
     The piezoelectric device  41  and the slider  11  are preferably bonded with great rigidity. For this purpose, the metal joints  51  are metal-joined to the surface electrode  43 B of the piezoelectric device  41 . Au/Au bonding using a gold paste is employed, for instance. The first and second terminal electrodes  45 A and  45 B may are preferably bonded to the electrode pads  52  by means of a gold paste, a silver paste or solder. Further, it is possible to extensively thin an adhesive layer which is either organic or inorganic, and has a high Young&#39;s modulus. 
     When an adhesive is used to bond the piezoelectric device  41  on the head element forming surface  11 A, the alumina layer  40  covering the head element  12  may be omitted because the adhesive fills in spaces between the head element  12 , head element forming surface  11 A and piezoelectric devices  41 . 
     The magnetic head  10  will be manufactured as described below. 
     First of all, the head elements  12  (illustrated in  FIG. 3 ) are made on an Al—TiC wafer  61  as illustrated in  FIG. 7A . Specifically, a plurality of rows of the head elements  12  are arranged in the shape of a matrix by a well-known process. Thereafter, the alumina layer  40  is spattered over the Al—TiC wafer  61  and head elements  12  as illustrated in  FIG. 7B , for instance. 
     Next, the alumina layer  40  is subject to the CMP (Chemical Mechanical Polishing), and has its surface smoothed. The metal joints  51  and electrode pads  52  (illustrated in  FIG. 6 ) are formed on the alumina layer  40  using a mask (not illustrated) and by the nonelectrolytic plating. In this case, openings are made on electrodes (not illustrated) pulled out from the head elements  12  by the photolithography, so that the electrode pads  52  for the head elements  12  are made in the openings. The metal joints  51  and electrode pads  52  are positioned over the head elements  12 . 
     Referring to  FIG. 8A , one piezoelectric device  41  is adhered onto the alumina layer  40  in such a manner that one surface electrode  43 A is in contact with one metal joint  51 . A gold paste is fixed to bond the piezoelectric device  41 , and is tied up by applying heat or ultrasonic waves. Further, the second terminal electrode  45 B and electrode pads  52  are bonded by a gold paste or the like. 
     The piezoelectric devices  41  will be manufactured as illustrated in  FIGS. 9A to 9D . 
     First of all, green sheets  71  for making piezoelectric layers  42  are produced using a PNN-ZPT piezoelectric ceramics powder, for instance. A Pt paste is screen-printed on one surface of each green sheet  71  in order to make inner electrode patterns  72 A and  72 B. When each piezoelectric device  41  has four layers, three green sheets  71  with the inner electrode patterns  72 A and  72 B will be produced. In such a case, the first and third green sheets  71  are provided with the inner electrode patterns  72 B so that the second inner electrodes (illustrated in  FIG. 5 ) will be formed. The second green sheet  71  is formed with the inner electrode patterns  72 B which are displaced, so that the first inner electrodes  44 A will be obtained. In short, the two inner electrode patterns  72 A and  72 B are alternately arranged depending upon a laminated order of the green sheets  71 . 
     The green sheets  71  are stacked in such a manner that the inner electrode patterns  72 A and  72 B are not in contact with one another. A green sheet  71  without the inner electrode patterns is laid on the top green sheet  71 . All of the green sheets  71  are united by a hot pressing process, and are calcined at 1050° C. in the atmosphere. Finally, a sintered sheet  73  is created as illustrated in  FIG. 9B . Thereafter, the sintered sheet  73  is polished and smoothed on its front and rear surfaces. 
     Next, referring to  FIG. 9C , an electrode pattern  74  is made on the opposite surfaces of the sintered sheet  73 . The electrode pattern  74  is in the shape of linked surface electrodes  34 A and  34 B having cuts as illustrated in  FIG. 5 . The electrode pattern  74  is formed by spattering Au onto the sintered sheet  73  via a metal mask, for instance. 
     The sintered sheet  73  is cut in rows by the dicing saw as illustrated by broken lines, thereby making a plurality of bars  75 . Referring to  FIG. 9D , ends of the first and second inner electrodes  44 A and  44 B are alternately exposed on a cut surface of each bar  75 . An electrode pattern  76  is made on another cut surface of each bar  75  by spattering Au via a metal mask. The electrode pattern  76  will be used as the terminal electrodes  45 A and  45 B after further processes. Each bar  75  will be sliced in a direction orthogonal to the lengthwise direction, so that the piezoelectric devices  41  (illustrated in  FIG. 5 ) will be completed. 
     As illustrated in  FIG. 8A , the piezoelectric devices  41  are metal bonded onto an Al—TiC wafer  61 , and then are cut in rows as illustrated by broken lines, so that magnetic head bars  77  will be made. On each of the bars  77 , a plurality of the piezoelectric devices  41  and the head elements  12  under the piezoelectric devices  41  are arranged. Further, a cut surface of each bar  77  is processed to make the air bearing surface  11 B of the slider  11 . The reading elements  28  are polished in order to adjust a length thereof. 
     The bar  77  is cut in the direction orthogonal to the lengthwise direction, and a size of cut pieces will be adjusted. The Al—TiC wafer  61  serves as the slider  11  (illustrated in  FIG. 2 ). The magnetic heads  10  which include the head elements  21  and piezoelectric devices  41  and are in the shape of a block will be completed. 
     A protective film may be provided on the piezoelectric devices  41  in order to protect them. The protective film may be made before or after the piezoelectric devices  41  are bonded onto the slider  11 . The protective film is preferably water resistant, and may be made of an inorganic or organic material. 
     The operation of the magnetic recording device will be described below. 
     When recording information on the magnetic disc  3  (illustrated in  FIG. 1 ), the carriage arm  4  is moved to a predetermined position. Electric recording signals are inputted in the magnetic head  10 . The magnetic recording head  20  at the tip of the magnetic head  10  produces magnetic fields in accordance with the information carried in the recording signals, applies the magnetic fields to minute regions of the magnetic disc  3 , and records magnetic information on the magnetic disc  3 . 
     In order to read the information from the magnetic disc  3 , the magnetic reading head  19  at the tip of the magnetic head  10  converts the information, stored in the minute regions of the magnetic disc  3 , into electric reading signals. 
     If a distance between the magnetic head  3 , magnetic reading head  19  and recording bead  20  is not appropriate, recording signals may be incorrectly written, or reading signals may be incorrectly read. 
     In order to overcome the foregoing problems, the control unit  8  activates the piezoelectric device  41  in response to an intensity of the signals read by the reading head  19 , thereby controlling the distance between the head element  12  and the magnetic disc  3 . To be more specific, the piezoelectric device  41  of the magnetic head  10  perpendicularly expands and contracts due to piezoelectric, lateral-and-perpendicular effect (d31 effect), minutely moves the head forming surface  11 A, and controls a sticking amount of the head element  12  to the air bearing surface  11 B. 
     A perpendicular expansion-and-contraction extent ΔL of the piezoelectric device  41  is expressed as follows: 
       Δ L=d 31× V×L/t,    
     where d31 denotes a piezoelectric lateral constant, V denotes an applied voltage, L denotes a length of the piezoelectric device  41 , and t denotes a thickness of the piezoelectric layer  42 . For instance, for d31=200 μm/V, V=30 V, L=150 μm and d=15 μm, ΔL will be 60 nm. 
     The piezoelectric device  41  is bonded on the head element forming surface  11 A in alignment with the mounting position of the head element  12 . Therefore, when expanding and contracting, the piezoelectric device  41  perpendicularly displaces the head element forming surface o 11 A of the slider  11  with respect to the magnetic disc  3 . 
     As a result, the sticking amount of the head element  12  over the air bearing surface  11 B will vary, so that the distance between the head element  12  and the magnetic disc  3  will be shortened. By controlling a voltage applied to the electrode pad  52  connected to the piezoelectric devices  41 , the sticking amount of the head element  12 , i.e. the distance between the head element  12  and the magnetic disc  3 , will be controlled with good response. In addition, the lower end of the head element  12  can be moved upward on the air bearing surface  11 B by regulating the voltage and contracting the piezoelectric devices  41 . 
     A displacement of the head element  12  has been simulated by attaching the piezoelectric devices  41  to the slider  11 . The piezoelectric device  41  is 500 μm wide, 200 μm high, and 60 μm thick. The piezoelectric device has four piezoelectric layers, each of which is 15 μm thick. An applied voltage is 300 volts. 
     Under the foregoing conditions, the sticking amount of the head elements  12  becomes 12.4 nm. Since a floating height of the slider  11  is 10 nm or less at present, the displacement of 12.4 nm is sufficient enough. A resonance frequency of the piezoelectric device  41  as the actuator is approximately 5 MHz, which is very high. This is so because only the head element forming surface  11 A of the slider  11  is selectively displaced, and neither the suspension  6  nor the slider  11  is displaced. 
     Properties of the magnetic heads  10  and properties of thermally sticking type magnetic heads of the related art are evaluated by a floating performance evaluating device. It is assumed that the piezoelectric devices are activated at a low frequency of 1 kHz in order to displace the magnetic heads  10 . Electric power consumed to accomplish the displacement under the foregoing condition is equal to or lower than 1/1000 compared with a case where the thermally sticking type magnetic heads are displaced by the same amount. Further, it is recognized that the magnetic heads  10  of this invention can be activated at a frequency which is 100 times higher than that for the sticking type magnetic heads. The magnetic heads  10  are confirmed to be very responsive. 
     As described above, in the magnetic recording device  1 , the piezoelectric device  41  is mounted on the head element  12  and the head element forming surface  11 A. Further, the tip of the head element  12  is perpendicularly displaced with respect to the recording surface of the magnetic disc  3  in accordance with the piezoelectric lateral-and-perpendicular effect. This is effective in displacing the head element  12  by a small amount, and in shortening response time. Therefore, it is possible to precisely control the distance between the head element  12  and the magnetic disc  3 . 
     The magnetic head  10  is manufactured after making the head element  12  and before machining the slider  11 . In short, the magnetic head  12  is manufactured simply by bonding the piezoelectric devices  41  on the Al—TiC substrate. This means that the magnetic head  10  can be manufactured with good productivity and increased yield. 
     The magnetic head  10  has a simple structure and can be easily manufactured without extensive modifications in the manufacturing process, compared to an existing structure in which the actuator is provided between the slider and head element, or in a structure in which the suspension is deformed. 
     Another example of the magnetic head will be described below. 
     In a magnetic head  10 B illustrated  FIGS. 10 and 11 , the slider  11  has the transverse groove  81  in the air bearing surface  11 B. The transverse groove  81  is positioned near the head element forming surface  11 A where the head element  12  is attached, has a predetermined depth, is substantially parallel to the head element  12 , and extends across the slider  11 . 
     The transverse groove  81  is effective in extensively alleviating the restriction on the lower part of the head element forming surface  11 A of the slider  11 . This is effective in enabling the head element  12  to be extensively displaced downward in response to the deformation of the piezoelectric device  41 . 
     The magnetic head  10 B will be manufactured as follows. The manufacturing process of the magnetic head  10 A is also applied until a bar  77  (illustrated in  FIG. 8B ) is made. 
     Referring to  FIG. 12 , after the bar  77  is manufactured, the transverse groove  81  is formed in a side surface (cut surface) of the bar  77  by using the dicing saw. The transverse groove  81  is machined to serve an air bearing surface  11 B. 
     Specifically, the transverse groove  81  is formed in the Al—TiC wafer  61 , is positioned near and in parallel to the magnetic head  12 . The air bearing surface  11 B of the slider  11  is then polished in order to control a length of the reading element  28 . When the bar  77  is sliced in the direction perpendicular to its length, the magnetic head  10 B including the slider  11 , head element  12  and piezoelectric device  41  will be completed as illustrated in  FIG. 11 . 
     Displacements of the head element  12  have been simulated for the transverse groove  81  which is made at a position which is 50 μm from the head element  12 . The transverse groove  81  is 50 μm deep. A sticking amount of the head element  12  is increased to 17.4 nm. It has been confirmed that the resonance frequency of the piezoelectric device  41  functioning as the actuator is substantially the same as in a case in which no transverse groove  81  is present. 
     The magnetic head  10 B is as effective as the foregoing magnetic head  10 A, and can extensively increase the displacement of the head element forming surface  11 A in response to the actuation of the piezoelectric device  41 . The transverse groove  81  can be easily and precisely made at a reduced cost by using the dicing saw. Alternatively, the transverse groove  81  may be made by the electric spark machining using a mask, the ion milling process or the like. Further, the transverse groove  81  may remain in a machined state. Alternatively, the transverse groove  81  may be filled with a material which has a small Young&#39;s modulus compared to the Al—TiC material used for the slider. In the following embodiments, the groove  81  may be filled as described above. 
     The transverse groove  81  does not have to be always straight. Although the transverse groove  81  extends across the slider  11 , it may be positioned only near the head element  12 . Further, the transverse groove  81  may have a width and a depth as desired. 
     Referring to  FIG. 13 , another magnetic head  10 C has the transverse groove  81  in the slider  11 . The magnetic head  10 C includes a piezoelectric device  41 A whose displacement height (illustrated by an arrow) is lower than the displacement height of the magnetic head  10 B. A height of the piezoelectric device  41 A may be larger than the depth of the transverse groove  81  and smaller than the height of the slider  11 , or smaller than the depth of the transverse groove  81 . 
     This is so because the magnetic head  12  is not extensively displaced even when the piezoelectric device  41 A is actuated at an area above the transverse groove  81 . In other words, the displacement of the head element  12  and response time are not affected even when the piezoelectric device  41 A is arranged to the area above the transverse groove  81 . The piezoelectric device  41 A is structured and manufactured similarly to the piezoelectric device  41  mentioned previously. 
     The magnetic head  10 C accomplishes the shortened response time and sufficient displacement by using the small piezoelectric device  41 A. 
     Referring to  FIG. 14 , a further magnetic head  10 D has a pair of perpendicular grooves  82  in addition to the transverse groove  81 . The perpendicular grooves  82  are positioned at opposite sides of the piezoelectric device  41 , and are integral with the head element forming surface  11 A and alumina layer  40  of the slider  11 . 
     The head element  12  is disposed between the perpendicular grooves  82 . Further, since the grooves  82  perpendicularly extend on the slider  11 , the electrode pad  52  to be connected to the head element  12  is positioned between the grooves  82 . 
     The perpendicular grooves  82  are deep enough to reach the slider  11  (Al—TiC wafer  61 ) via the alumina layer  40 , and communicate with the transverse groove  81  in the air bearing surface  11 B. 
     One electrode pad  52  is formed between the perpendicular grooves  82  in order that a terminal of the head element  12  is not cut by the perpendicular grooves  82 . 
     The perpendicular grooves  82  are effective in alleviating the restraint on the head element  12  in a widthwise direction (laterally) with respect to the slider  11 . Therefore, the head element forming surface  11 A is easily and extensively displaced at its bottom when the piezoelectric device  41  is activated. 
     The perpendicular grooves  82  may not reach the transverse groove  81  in the air bearing surface  11 B, and may not be straight. Further, the perpendicular grooves  82  may not extend to the upper and lower surfaces of the slider  11 , and may be formed only near the head element  12 . The perpendicular grooves  82  have a width and a depth as desired. 
     The low piezoelectric device  41 A (illustrated in  FIG. 13 ) may be used in place of the piezoelectric device  41 . The transverse groove  81  in the air bearing surface  11 B may be omitted. The head element  12  is easily displaced at its bottom since the perpendicular grooves  82  alleviate the restraint on the head element  12  in the widthwise direction. 
     Referring to  FIG. 15 , a magnetic head  10 E includes a piezoelectric device  41 B. The piezoelectric device  41 B has first and second terminal electrodes  45 C and  45 D at its opposite sides. 
     The surface electrode  43 B differs from the surface electrode  43 B illustrated in  FIG. 4 , has a cut at a part near the second terminal electrode  45 D, is not in contact with the second terminal electrode  45 D, and is electrically connected to the first terminal electrode  45 C. The surface electrode  43 A has another cut at a part near the first terminal electrode  45 C, is not in contact with the first terminal electrode  45 C, and is electrically connected to the second terminal electrode  45 D. 
     The piezoelectric layer  42  is exposed on the side, upper and lower surfaces of the piezoelectric device  41 B except at the first and second terminal electrodes  45 C and  45 D. The first and second inner electrodes  44 A and  44 B (illustrated in  FIG. 4 ) facing with each other are electrically connected to the first or second terminal electrodes  45 C or  45 D. 
     The magnetic head  10 E including the piezoelectric device  41 B is as effective as the magnetic heads referred to previously. 
     Second Embodiment 
       FIGS. 16 and 17  illustrate a magnetic head  100  of a magnetic recording device. 
     According to a second embodiment of the invention, the magnetic head  100  includes the head element  12  mounted on the slider  11 , and a piezoelectric device  101  functioning as an actuator. The piezoelectric device  101  is bonded to the head element forming surface  11 A via the alumina layer  40 . 
     In the second embodiment, the piezoelectric device  101  has a structure in which thin layers are stuck in a direction perpendicular to the air bearing surface  11 B, and expands and contracts due to the piezoelectric perpendicular effect (d33 effect). 
     Specifically, the piezoelectric device  101  includes piezoelectric layers  42  having electrodes. The piezoelectric layers  42  are stuck in parallel to the head element forming surface  11 A, i.e. substantially in the direction perpendicular to the air bearing surface  11 B. The piezoelectric device  101  includes first and second terminal electrodes  102 A and  102 B, and a plurality of inner electrodes  103 A and  103 B positioned between the piezoelectric layers  42 . 
     The first and second terminal electrodes  102 A and  102 B are connected to the alumina layer  40  on the slider  11  using a conductive adhesive (e.g. a gold paste). The inner electrodes  103 A and  103 B are electrically connected to either the first terminal electrode  102 A or the second terminal electrode  102 B. More specifically, the inner electrodes  103 A and  103 B are alternately connected to the first terminal electrode  102 A and the second terminal electrode  102 B in accordance with their laminated direction. 
     In the structure illustrated in  FIG. 16 , the first terminal electrode  102 A is connected to the positive (+) pole of the power source, and the second terminal electrode  102 B is connected to the negative (−) pole of the power source. In this state, the inner electrodes  103 A on second and fourth layers have the positive potential while the inner electrodes  103 B on first, third and fifth layers have the negative potential. The number of the piezoelectric layers  42 , and that of the inner electrodes  103 A and  103 B are not always limited to those illustrated in  FIG. 16 . 
     Materials of the piezoelectric device  101  and electrodes are similar to those used for the magnetic recording device in the first embodiment. Further, the piezoelectric device  101  is bonded to the slider  11  similarly to the piezoelectric device in the first embodiment. Still further, the piezoelectric device  101  may be rectangular, and is easily manufactured. 
     The magnetic head  100  will be manufactured as described below. 
     First of all, the head elements  12  are made on the Al—TiC wafer  61  by the well-known process (see  FIG. 7A ). Thereafter, the alumina layer  40  is spattered on the head elements  12 , and is polished and smoothed (see  FIG. 7B ). 
     The electrode pads  52  are formed on the alumina layer  40  by the nonelectrolytic plating and using a mask (not illustrated). Openings are made on electrodes (not illustrated) drawn from the head elements  12 , by the photolithographic process. The electrode pad  52  for the head elements  12  is made in the openings. 
     The piezoelectric devices  101  are bonded to the head elements  12  one by one. In this state, edges of the inner electrodes  103 A and  103 B are exposed on the bonded surfaces of the piezoelectric devices  101 . In order to prevent short-circuiting, the piezoelectric devices  101  except for the first and second electrode  102 A and  102 B are bonded to the alumina layer  40  using an insulating adhesive but not using the gold paste, silver paste or the like. Alternatively, front and rear surfaces of the piezoelectric devices  101  may be covered by an insulating film. The piezoelectric devices  101  are bonded to the alumina layer  40  using a conductive or insulating adhesive. This bonding process will be applied to other piezoelectric devices which operate due to the piezoelectric perpendicular effect (d33 effect). 
     The adhesive sufficiently fills spaces between the head elements  12  and the piezoelectric devices  101 . Therefore, the piezoelectric devices  101  may be bonded to the head elements  12  and the head element forming surface  11 A via the adhesive. In such a case, the alumina layer  40  on the Al—TiC wafer  61  may be omitted. 
     The piezoelectric devices  101  are manufactured in the following steps. Referring to  FIG. 18A , inner electrode patterns  105 A and  105 B are screen printed on green sheets  71  made of PNN-ZPT piezoelectric ceramics powder, for instance. A Pt paste is used for the screen printing. In this state, the inner electrode patterns  105 A and  105 B are in the shape of parallel strips. 
     When the piezoelectric devices  101  have a four-layer structure, three green sheets  71  carrying the inner electrode patterns  105 A and  105 B are prepared. In this case, the first inner electrode patterns  105 A are formed on the first and third green sheets  71  in order to make the inner electrodes  103 A. The second inner electrode patterns  105 B are formed on the second green sheet  71  in order to make the inner electrodes  103  (illustrated in  FIG. 16 ). The second inner electrode patterns  105 B overlap on the first inner electrode patterns  105 A. The first and second inner electrode patterns  105 A and  105 B are alternately made. 
     A plurality of green sheets  71  are stacked in such a manner that the inner electrode patterns  105 A and  105 B are not in contact with one another. A green sheet  71   a  without any inner electrode patterns is placed on the inner electrode patterns  105 A on the topmost green sheet  71 . The stacked green sheets  71  and  71   a  are hot rolled in order to unite them, and are calcined in the atmosphere at 1050° C. As illustrated in  FIG. 18B , a sintered sheet  106  is obtained, and is polished and smoothed. 
     The sintered sheet  106  is cut into a plurality of bars  107  using the dicing saw as illustrated by broken lines. In this state, the inner electrode patterns  105 A and  105 B are changed to the inner electrodes  103 A and  103 B. Referring to  FIG. 18C , the inner electrodes  103 A and  103 B are alternately exposed at ends of each bar  107 . 
     Electrode patterns  108  are made by spattering Au onto the opposite ends of the bar  17  where the edges of the inner electrodes  103 A and  103 B are exposed. Thereafter, the bar  107  is sliced, thereby obtaining piezoelectric devices  101 . The electrode patterns  108  serve as the first and second terminal electrodes  102 A and  102 B. 
     In each bar  107 , a plurality of piezoelectric devices  101  and a plurality of head elements  12  under the piezoelectric devices  101  are arranged in a row with spaces maintained between them. One of the cut surfaces (side surfaces) of the bar  107  is machined to make the air bearing surface  11 B of the slider  11 . A length of the recording elements  28  in the head elements  12  is adjusted. Thereafter, the bar  107  is sliced in the direction orthogonal to its lengthwise direction, thereby obtaining the magnetic head  100  illustrated in  FIG. 16 . 
     A protective film may be formed on the piezoelectric devices  101  in order to protect them as in the first embodiment. 
     The piezoelectric devices  101  are bonded onto the Al—TiC wafer  61  in the shape of matrix as in the first embodiment. For instance, one of the cut surfaces of the piezoelectric devices  101  is bonded by an adhesive onto the alumina layer  40  extending over the head element forming surface  11 A. 
     Further, the first and second terminal electrodes  102 A and  102 B on the opposite surfaces of the piezoelectric devices  101  are aligned with the electrode pads  52  on the slider  11 , and are electrically joined to the electrode pads  52  by a conductive adhesive like a gold paste. 
     Then, the bars  107  are sliced as illustrated in  FIG. 8B , and bars  109  will be obtained. 
     In each bar  109 , a plurality of piezoelectric devices  101  and a plurality of head elements  12  under the piezoelectric devices  101  are arranged in a row with spaces maintained between them. One of the cut surfaces (side surfaces) of the bar  109  is machined to make the air bearing surface  11 B of the slider  11 . A length of the recording elements  28  in the head elements  12  is adjusted. Thereafter, the bar  109  is sliced in the direction orthogonal to its lengthwise direction, thereby obtaining the magnetic head  100  illustrated in  FIG. 16 . 
     A protective film may be formed on the piezoelectric devices  101  in order to protect them as in the first embodiment. 
     The operation of the magnetic recording device  1  of the second embodiment will be described below. 
     With the magnetic recording device  1 , a sticking amount of the head element  12  on the air bearing surface  11 B is controlled by bonding the minute piezoelectric device  101  to the head element forming surface  11 A of the slider  11 . The piezoelectric device  101  expands and contracts due to the piezoelectric perpendicular effect (d33 effect). 
     A perpendicular expansion-and-contraction extent ΔL of the piezoelectric device  101  is obtained as follows: 
       Δ L=n×d 33× V,    
     where “n” denotes the number of piezoelectric layers, d33 denotes a piezoelectric constant, and V denotes an applied voltage. For n=10, d33=650 nm/V and V=30 V, ΔL will be 186 nm. 
     The piezoelectric device  101  is positioned where the head element  12  is mounted, and around the head element  12 . In response to the expansion and contraction of the piezoelectric device  101 , a part of the slider  11  including the head element  12  is perpendicularly displaced with respect to the surface of the magnetic disc  3  as illustrated by a phantom line in  FIG. 17 . Therefore, the sticking amount of the head element  12  varies, and the distance between the head element  12  and the magnetic disc  3  becomes appropriate. The sticking amount of the head element  12 , i.e. the distance between the head element  12  and the magnetic disc  3 , can be precisely controlled by regulating the voltage applied to the piezoelectric device  101 . 
     The displacement of the head element  12  has been simulated for the piezoelectric devices  101  which are bonded to the head element forming surface  11 A of the slider  11 . The piezoelectric devices  101  are 500 μm wide, 200 μm high, and 50 μm thick. The piezoelectric layer is 20 μm thick. Ten piezoelectric layers are used. The applied voltage is 30 V. Under these conditions, the sticking amount of the head elements  12  becomes 15.6 nm, and is considered to be sufficient as a floating distance of a hard disc drive. A resonance frequency of the piezoelectric devices  101  becomes approximately 5 MHz, which seems very high. This is so because only the area near the head element  12  is displaced, and neither the suspension  6  nor the slider  11  is displaced as a whole. 
     Properties of the magnetic head  100  and properties of thermally sticking type magnetic heads of the related art are evaluated by the floating performance evaluating apparatus. The magnetic heads  100  are activated at a low frequency of 1 kHz in order to displace the magnetic head  100 . Under the foregoing conditions, electric power consumed to accomplish the displacement is equal to or lower than 1/1000 compared with a case where the thermally sticking type magnetic heads are displaced by the same amount. Further, it is recognized that the magnetic heads  100  of this invention can be activated at a frequency which is 100 times higher than that for the sticking type magnetic heads. Further, the magnetic heads  10  are confirmed to be very responsive. 
     In this embodiment, the piezoelectric device  101  is attached above the head element  12  on the head element forming surface  11 A of the slider  11 . The head element  12  is made to be displaced due to the piezoelectric perpendicular effect of the piezoelectric device  101 , which shortens the response time of the magnetic head  10 . The floating distance of the magnetic head  10  with respect to the magnetic disc  3 , more specifically the floating distance of the head element  12 , can be actively and precisely controlled. 
     Compared to the related art, the piezoelectric device  101  is attached to the magnetic head  100  without an actuator after manufacturing the head element  12 . Since only this process is added, the magnetic recording device  1  has a simple structure, and can be manufactured with ease. Further, with the magnetic recording device  1 , the distance between the head element  12  and the magnetic disc  3  can be reliably maintained constant, which enables data to be read out and written in optimum states. 
     With the magnetic head  1  illustrated in  FIG. 16 , the electrode pads  52  are made on the head element forming element surface  11 A. Alternatively, they may be made on a side or upper surface of the slider  11  or the like. 
     A further example of the second embodiment will be described below. 
     Referring to  FIGS. 19 and 20 , a magnetic head  100 B has the transverse groove  81  in the air bearing surface  11 B of the slider  11 . The transverse groove  81  extends across the slider  11 . The presence of the transverse groove  81  enables an area adjacent to the head element  12  of the slider  11  to be free from the other areas, and enables the head element  12  and its adjacent area to be easily displaced when the piezoelectric device  101  is activated. 
     The magnetic head  100 B is manufactured as follows. The Al—TiC wafer  61  is cut in order to make the bar  109  as illustrated in  FIG. 8B . The transverse groove  81  is made, using the dicing saw, on a side surface (cut surface) of the bar  109 , which is machined to form the air bearing surface  11 B. A length of a main magnetic pole  31  is adjusted. The bar  109  is sliced along its length, so that the magnetic heads  100 B will be completed. 
     The displacement of the head element  12  has been simulated for the transverse groove  81  which is made in the slider  11  to a position which is 50 μm from the air bearing surface  11 B. The transverse groove  81  is 50 μm deep. The sticking amount of the head element  12  is increased to 32 nm compared to a case in which there is no transverse groove  81 . The resonance frequency is approximately same as the resonance frequency in the case where there is no transverse groove  81 . 
     The magnetic head  100 B illustrated in  FIGS. 19 and 20  is as effective as the foregoing magnetic heads, and can further increase the displacement. The transverse groove  81  may be made as described in the first embodiment, or may be filled with the filling agent used in the first embodiment. 
     Referring to  FIG. 21 , a still further magnetic head  100 C has a transverse groove  81  in the air bearing surface  11 B near the head element forming surface  11 A. The magnetic head  100 C also has a piezoelectric device  101 A which is lower than the magnetic head  100  illustrated in  FIG. 16 . A displacement caused by the piezoelectric device  101 A is small at an area above the transverse groove  81  compared to that at the area where the transverse groove  81  is present. 
     The piezoelectric device  101  extends over a small area above the transverse groove  81 , and efficiently activates the head element forming surface  11 A. 
     Referring to  FIG. 22 , a magnetic head  100 D has a pair of perpendicular grooves  82  which are formed in the head element forming surface  11 A of the slider  11  and on the alumina layer  40  at the opposite sides of a piezoelectric device  101 B. The piezoelectric device  101 B is narrower than the piezoelectric device  101 A in the foregoing example. 
     The head element  12  is positioned between the perpendicular grooves  82 . The perpendicular grooves  82  extend on the slider  11 , and are deep enough to reach the transverse groove  81  in the air bearing surface  11 B. 
     The area defined by the perpendicular grooves  82  and the alumina layer  40  cab be spatially separate from other components, and are less affected by restraint from the other components. Therefore, the displacement of the head element  12  can be extensively increased when the piezoelectric device  101 B is activated. Further, the perpendicular grooves  82  allow the use of the small and narrow piezoelectric device  101 B, and improve the activation efficiency. 
     All of the electrode pads  52  are positioned between the perpendicular grooves  82  in order to prevent the terminals of the head element  12  from being cut by the perpendicular grooves  82 . 
     The perpendicular grooves  82  do not always have to reach the transverse groove  81  in the air bearing surface  11 B. Further, the piezoelectric device  101  or  101 A (illustrated in  FIGS. 16 and 21 ) may be used in place of the piezoelectric device  101 B illustrated in  FIG. 22 . 
     A magnetic head  100 E illustrated in  FIG. 23  includes a piezoelectric device  101 C which expands and contracts due to the piezoelectric perpendicular effect. 
     In the piezoelectric device  101 C, the arrangement of the first and second terminal electrodes  102 C and  102 D for drawing the inner electrodes  103 A and  103 B differs from the arrangement of the piezoelectric devices  101 ,  101 A and  101 B illustrated in  FIGS. 16 ,  21 , and  22 . 
     The first and second terminal electrodes  102 C and  102 D are placed on front and rear surfaces of the piezoelectric layer  42  which are parallel to the head element forming surface  11 A, and are alternately connected to rear and front ends of the inner electrodes  103 A and  103 B. 
     The piezoelectric device  101 C includes a metal joint  51  linking to one of electrode pads  52  is on the alumina layer  40 . The first terminal electrode  102 C is bonded to the metal joint  51  using a gold paste, a silver paste or the like. This enables the first terminal electrode  102 C to be electrically connected to and bonded to the electrode pad  52  at the same time. 
     The second terminal electrode  102 D is made on the front surface of the piezoelectric layer  42 , and is electrically connected to a third terminal electrode  121  on the upper surface of the piezoelectric layer  42 . The third terminal electrode  121  is shaped so that it is not in contact with the first terminal electrode  102 C because of the presence of a cut on the first terminal electrode  102 C. The third terminal electrode  121  is connected to another electrode pad  52  using a gold paste, a silver paste or the like. 
     The second terminal electrode  102 D and the electrode pad  52  may not be connected via the pattern on the piezoelectric device  101 C although the third terminal electrode  121  is connected via the pattern. For instance, the second terminal electrode  102 D may be electrically connected to the electrode pad  52  using a conductive wire  131  such as a gold wire as illustrated in  FIGS. 24A and 24B . 
     Referring to  FIGS. 24A and 24B , a piezoelectric device  101 D is mounted at an area of the alumina layer  40  which covers the head element  12  in the slider  11 , and expands and contracts due to the piezoelectric perpendicular effect. 
     The piezoelectric device  101 D includes a plurality of inner electrodes  103 A and  103 B which are arranged perpendicularly and in parallel in the piezoelectric layer  42  with spaces maintained between them. The piezoelectric device  101 D has surface electrodes  130  on the upper and lower surfaces. 
     Front and rear edges of the surface electrodes  130  and inner electrodes  103 A and  103 B are alternately exposed on front and rear surfaces of the piezoelectric layer  42 . The inner electrode  103 A and surface electrodes  130  exposed on the rear surface of the piezoelectric layer  42  are connected to the first terminal electrode  102 C on the rear surface of the piezoelectric layer  42 . 
     The inner electrode  103 B is connected to the second terminal electrode  102 D on the front surface of the piezoelectric layer  42 . 
     The first terminal electrode  102 C and the surface electrodes  130  are not in contact with one another. The first and second terminal electrodes  102 C and  102 D are independent in the piezoelectric device  101 D. 
     Referring to  FIG. 24A , the first terminal electrode  102 C of the piezoelectric device  101 D is bonded, using a gold paste, a silver paste or the like, on the metal joint  51  which is made on the alumina layer  40  of the head element forming surface  11 A and is linked to one of electrode pads  52 . 
     The second terminal electrode  102 D is bonded to another electrode pad  52   c  using a gold wire  131  as illustrated in  FIG. 24B . 
     Therefore, the second electrode pad  52 C on the alumina layer  40  outside one of the perpendicular grooves  82  can be electrically connected to the piezoelectric device  101 D. This enables the density of the second electrode pads  52  on the alumina layer  40  in the area defined by the perpendicular grooves  82  can be lowered, so that the electrode pads  52  can be easily connected to external wirings. 
     Third Embodiment 
       FIG. 25  illustrates a piezoelectric device  140  constituting a magnetic recording device according to a third embodiment. 
     The sticking amount of the head element  12  on the air bearing surface  11 B is controlled by the expansion and contraction of the piezoelectric device  140  caused by the piezoelectric perpendicular effect in the direction substantially perpendicular to the air bearing surface  11 B. 
     The piezoelectric device  140  includes a plurality of piezoelectric layers  42  which are stacked in the direction perpendicular to the air bearing surface  11 B. In the piezoelectric layer  42 , a plurality of first and second inner electrodes  141 A and  141 B are alternately stacked with spaces maintained between them. Surface electrodes  142  are placed on bottom and top piezoelectric layers  42 . The top piezoelectric layer  42  faces with the magnetic disc  3 . 
     The second inner electrode  141 B and the surface electrode  142  interleave the first inner electrode  141 A with spaces maintained between them. The surface electrodes  142 , and the first and second inner electrodes  141 A and  141 B interleave the piezoelectric layers  42  between them. 
     First and second terminal electrodes  143 A and  143 B are made on opposite surfaces of each piezoelectric layer  42 . The first terminal electrode  143 A is connected to one end each of the surface electrode  142  and inner electrode  141 B. The second terminal electrode  143 B is connected to the other end of the first inner electrode  141 A. 
     Referring to  FIG. 25 , a border between the second terminal electrode  143 B and surface electrode  142  is electrically separated by laser trimming two corners of the piezoelectric device  140  or another process. 
     The laminated piezoelectric device  140  will be manufactured by the following process. 
     A plurality of green sheets made of PNN-PZT piezoelectric ceramics are prepared as in the process referred to in the second embodiment. Metal patterns in the shape of strips are formed on some of the green sheets. The metal patterns are used as the first inner electrodes  141 A. Further, metal patterns in the shape of strips are made on the remaining green sheets, and are used as the second inner electrodes  141 B. 
     The patterns for the first and second inner electrodes  141 A and  141 B are alternately stacked so that they are not in contact with one another. A green sheet without any inner electrode pattern is placed on the exposed top green sheet carrying the inner electrode patterns for the first inner electrodes  141 A. The green sheets are calcined under the conditions referred to in the second embodiment, thereby obtaining a sintered sheet. The sintered sheet is cut using the dicing saw to make a bar which is similar to that illustrated in  FIG. 18C . 
     As illustrated in  FIG. 26A , a gold electrode  143  is made by spattering gold onto the four surfaces of the bar. Then, two corners  145  of the bar where side edges of the first inner electrode patterns  141 A are exposed are polished in order to expose a piezoelectric material. 
     Thereafter, the bar is sliced, so that the piezoelectric devices  140  (illustrated in  FIG. 25 ) are completed. 
     A pair of electrodes  52 D and  52 E for the piezoelectric devices  140  are made on the alumina layer  40  extending over the head element  12 . The alumina layer  40  is present on one surface of the slider  11  where the piezoelectric device  140  is attached. The electrode pads  52 D and  52 E are connected, using lead wires, to center electrodes  52   a  and  52   b  at the upper part of the slider  11 . 
     Referring to  FIG. 27B , the piezoelectric device  140  is attached to the slider  11  by bonding the first and second terminal electrodes  143 A and  143 B to the electrode pads  52 D and  52 E via conductive adhesives  52 F and  52 G. A gold ball, a solder ball or the like may be used as the conductive adhesives  52 F and  52 G. 
     When a predetermined voltage is applied, the piezoelectric device  140  expands and contracts in the directions illustrated by arrowheads as illustrated in  FIG. 25 . Therefore, a part of the slider  11  near the piezoelectric device  140  is displaced in the directions illustrated by arrowheads, thereby controlling the sticking amount of the head element  12  from the air bearing surface  11 B. 
     Properties of the magnetic heads  146  and those of thermally sticking type magnetic heads are evaluated using the floating performance evaluating device. When activated at a low frequency of 1 kHz, the magnetic heads  146  may consume 1/1000 or less power in order to displace by an amount which is accomplished by the thermally sticking type magnetic heads. As for frequency characteristics, the magnetic heads  146  can be activated at a frequency which is 100 times higher than a frequency for the thermally sticking type magnetic heads. The magnetic heads  146  have a very high response speed. 
     With the magnetic recording device  1  including the magnetic head  146  having the piezoelectric device  140 , the sticking amount of the head element  12  on the air bearing surface  11 B can be controlled by the piezoelectric perpendicular effect of the piezoelectric device  140 . The magnetic recording device  1  of this embodiment is as effective as the magnetic recording device  1  of the second embodiment. 
     The magnetic head  146  has the transverse groove  81  in the air bearing surface  11 B of the slider  11  as illustrated in  FIG. 27 . Alternatively, the transverse groove  81  may be omitted, or the perpendicular grooves  82  may be made as illustrated in  FIG. 14 . 
     Fourth Embodiment 
       FIG. 28  is a front elevation of a magnetic head  150  of a magnetic recording device  1  according to a fourth embodiment of the invention, viewed from a surface where the head element  12  is attached to the magnetic head  150 . 
     In the magnetic head  150 , a piezoelectric device  151  is mounted on the alumina layer  40  extending over the head element forming surface  11 A. The piezoelectric device  151  has the piezoelectric layer  42  which is formed by thin piezoelectric films arranged in a direction perpendicular to the air bearing surface  11 B of the slider  11 . The piezoelectric device  151  controls the sticking amount of the head element  12  on the air bearing surface  11 B in accordance with the expansion and contraction due to the piezoelectric perpendicular effect (d33 effect). 
     In the piezoelectric device  151 , inner electrodes  152  are provided between the thin films of the piezoelectric layer  42 . The inner electrodes  152  transversely extend through the piezoelectric layer  42 , and have their opposite ends exposed. The exposed ends of the inner electrodes  152  are alternately covered by insulating films  153 . 
     Specifically, as illustrated in  FIG. 28 , left ends of the inner electrodes  152  on the second and fourth thin films of the piezoelectric layer  42  are covered by the insulating films  153 . Further, right ends of the inner electrodes on the first, third and fifth thin films of the piezoelectric layer  42  are covered by the insulating films  153 . 
     A first terminal electrode  154 A is formed on the exposed left ends of the inner electrodes  152  on the second and fourth thin films of the piezoelectric layer  42 , and is connected to the inner electrodes  152  on the second and fourth thin films of the piezoelectric layer  42 . In the similar manner, a second terminal electrode  154 B is formed on the exposed left ends of the inner electrodes  152  on the first, third and fifth thin films, and is connected to the inner electrodes  152  on the first, third and fifth thin films. 
     The first terminal electrode  154 A extends on the top or bottom thin film of the piezoelectric layer  42 , and also serves as a surface electrode. 
     The following describe a process for manufacturing the piezoelectric device  151  with reference to  FIGS. 29A to 29B . 
     As illustrated in  FIG. 29A , inner electrode patterns  161  are made on predetermined areas of a green sheet  71  by using a Pt paste and by the screen printing process. In this case, the green sheet  71  is made of PNN-PZT ceramics powder. Further, no inner electrode patterns  161  are made on opposite side edges of the green sheet  71 . The inner electrode patterns  161  are flat and rectangular. Alternatively, the inner electrode patterns  161  may be made all over the green sheet  71 . 
     A plurality of green sheets  71  carrying the inner electrode patterns  161  is prepared. The green sheets  71  are stacked, and are covered by a green sheet  71   a  without the inner electrode patterns  161 . The green sheets  71  and  71   a  are hot pressed, and are calcined at 1050° C. in the atmosphere, thereby obtaining a sintered plate  162  as illustrated in  FIG. 29B . The sintered plate  162  has its front and rear surfaces polished and smoothed. 
     Further, the sintered plate  162  is cut into strips as illustrated by broken lines, thereby making bars  163  illustrated in  FIG. 29C . The inner electrode patterns  161  are cut to make inner electrodes  152 . The inner electrodes  152  are exposed on a cut surface  163 A of each bar  163 . 
     A photosensitive material such as SOG (spin-on-glass) is applied onto a side surface  163 A of the bar  163  where terminal electrodes  154 A and  154 B will be made. The side surface  163 A covered by the SOG is exposed to light, so that glass patterns  164  are made in order to alternately cover left and right edges of a plurality of inner electrodes  152 . The SOG which is not exposed to light is removed using a solvent. In this state, insulating films  153  will be made as illustrated in  FIG. 28 . 
     A photosensitive resin such as photosensitive polyimide may be used in place of the photosensitive SOG in order to make the insulating films  153  by screen-printing. 
     Glass films  164  alternately cover every two ends of the inner electrodes  152  on the opposite surfaces  163 A of the bar  163 . When the glass film  164  is present on one surface  163 A and covers the inner electrode  152 , no glass film  164  is present on the other surface  163 A. This means that the glass films  164  alternately cover the inner electrodes  152  at the opposite surfaces  163 A in the laminated direction. 
     Referring to  FIGS. 30A to 30C , a gold electrode film  165  is applied on the side surfaces  163 A of the bar  163 , upper and lower surfaces  163 B of the bar  163  and the insulating film  153  by means of the spattering process. 
     Thereafter, upper and lower corners on one side surface of the electrode film  165  where the glass film  164  is present are removed by the laser trimming process. 
     In this state, the electrode film  165  is divided into two parts, which serve as a pair of terminal electrodes  154 A and  154 B. The bar  163  is sliced as illustrated in  FIG. 30C , thereby obtaining the piezoelectric devices  151 . An insulating film of SOG may be formed on a sliced surface where the piezoelectric device  151  does not face with the slider  11 . 
     Electrode pads  52  are made on the Al—TiC wafer  61  where the head element  11  has been completed. The piezoelectric device  151  is bonded on the alumina layer  40  covering the Al—TiC wafer  61  as in the foregoing embodiments. 
     Referring to  FIG. 31A , a plurality of first grooves  171  are made in parallel on the Al—TiC wafer  61  in such a manner that they interleave the piezoelectric devices  151  and the head elements  12  under the piezoelectric devices  151 . 
     Then, the Al—TiC wafer  61  is cut into rows in the direction orthogonal to the first grooves  171 , thereby obtaining bars  172 , one of which is illustrated in  FIG. 31B . 
     With bar  172 , a second groove  173  is formed in a cut side surface  172 A of the Al—TiC wafer  61  using the dicing saw or the like. The cut side surface  172 A will serve as the air bearing surface  11 B of the slider  11 . The second groove  173  is present near the head element forming surface  11 A where the head element  12  is mounted, and is approximately in parallel to the head element  12 . Referring to  FIG. 31B , the second groove  173  communicates with the first groove  171 . Alternatively, the second groove  173  may be present at a position where it does not communicate with the first groove  171 . The side surface  172 A where the second grooves  171  are present is machined and polished to make the air bearing surface  11 B. A length of the reading element  28  is adjusted. Thereafter, the bar  172  will be sliced. 
     In this state, the magnetic head  150  (illustrated in  FIG. 28 ) will be completed. The first groove  171  serves as the perpendicular grooves  82  while the second groove  173  serves as the transverse groove  81 . Alternatively, the first groove  171  may be made before the piezoelectric device  151  is bonded. 
     In the magnetic head  150 , the piezoelectric device  151  is bonded to the head element forming surface  11 A via the alumina layer  40 . A pair of perpendicular grooves  82  is formed in the opposite sides of the piezoelectric device  151 . Further, one transverse groove  81  is formed in the air bearing surface  11 B near the head element  12 . 
     In the magnetic recording device  1 , when a voltage is applied, the piezoelectric device  151  expands and contracts due to the piezoelectric perpendicular effect (d33 effect) as illustrated by the arrowheads in  FIG. 28 . Therefore, a part of the slider  11  near the piezoelectric device  151  is displaced as illustrated by the arrowheads, so that the sticking amount of the head element  12  on the air bearing surface  11 B is controlled. 
     Properties of the magnetic heads  150  and those of thermally sticking type magnetic heads are evaluated using the floating performance evaluating device. When activated at a low frequency of 1 kHz, the magnetic heads  146  may consume 1/1000 or less power in order to be displaced by an amount which is accomplished by the thermally sticking type magnetic heads. As for frequency characteristics, the magnetic heads  146  can be activated at a frequency which is 100 times higher than a frequency for the thermally sticking type magnetic heads. The magnetic heads  146  are very responsive. 
     With the magnetic recording device  1  including the magnetic head  181  and the piezoelectric device  151 , the sticking amount of the head element  12  on the air bearing surface  11 B can be controlled with good response in response to the expansion and contraction of the piezoelectric device  151  due to the piezoelectric perpendicular effect. The magnetic recording device  1  of this embodiment is as effective as the magnetic recording device  1  of the second embodiment. Either the transverse groove  81  or the perpendicular grooves  82  may be omitted in the magnetic head  146 . 
     Fifth Embodiment 
       FIG. 32  is a side elevation of a magnetic head  200  of a magnetic recording device according to a fifth embodiment. 
     The magnetic head  200  includes the piezoelectric device  101  attached on the alumina layer  40  extending over the head element forming surface  11 A. The piezoelectric device  101  includes the piezoelectric layer  42  in which thin piezoelectric films are stacked in a direction perpendicular to the air bearing surface  11 B of a slider  11 . The piezoelectric device  101  expands and contracts due to the piezoelectric perpendicular effect (d33 effect), and controls the sticking amount of the head element  12  on the air bearing surface  11 B of the slider  11 . 
     The magnetic head  200  has a transverse groove  201  which is made by machining the head element forming surface  11 A of the slider  11 . More specifically, the transverse groove  201  is a step made on the head element forming surface  11 A, is in parallel to the head element  12 , and extends across the slider  11 . 
     A depth of the transverse groove  201  is approximately equal to the height of the head element  12 . The transverse groove  201  reaches at its bottom the air bearing surface  11 B. For instance, the groove  201  is 50 μm deep, and 2 μm wide in a direction parallel to the air bearing surface  11 B of the slider  11 . Alternatively, the depth of the groove  201  may be larger or smaller than the height of the head element  12  so long as the head element  12  can be freely displaced. 
     The transverse groove  201  has a length which is equal to the width of the slider  11 . The transverse groove  201  may be shorter than the width of the slider  11  so long as the head element  12  can be positioned at the center of the head element forming surface  11 A, and so long as the head element  12  can be freely displaced. However, the transverse groove  201  is longer than the width of the head element  12  in order to enable the head element  12  to be easily displaced. 
     The transverse groove  201  is filled with polyimide as a heat resistant resin  202 . The heat resistant resin  202  may be any resin which has a Young&#39;s modulus lower than that of the slider  11 , remains stable at a high temperature of approximately 250° C., which is an upper limit of the head element making process. The heat resistant resin  202  may be aramid group fiber, polyether ether ketone group resin, or polyether sulfone group resin. 
     The magnetic head  200  will be manufactured as follows. 
     As illustrated in  FIG. 33A , resist patterns are formed on the head element forming surface  11 A of the Al—TiC wafer  61 . A plurality of parallel grooves  210  are formed in the Al—TiC wafer  61  by the ion milling or reactive plasma etching process. The grooves  210  are 30 μm to 150 μm wide (corresponding to the height (depth) illustrated in  FIG. 32 ), and 0.1 μm to 10 μm deep (corresponding to the width illustrated in  FIG. 32 ), considering ease of the displacement of the head element  12  and mechanical strength for supporting the head element  12 . As illustrated in  FIG. 33B , the heat resistant resin  22  like polyimide is applied onto the head element forming surface  11 A. Finally, the heat resistant resin filled in the groove  210  is hardened. 
     The head element forming surface  11 A on the Al—TiC wafer  61  is polished by the CMP process in order to remove surplus heat resistant region  202 , and has its surface smoothed. In this state, as illustrated in  FIG. 34A , the heat resistant resin  202  is left only in the groove  210 . 
     Further, an insulating alumina film  203  or the like is made on the head element forming surface  11 A on the Al—TiC wafer  6  and on the heat resistant resin  202  filled in the groove  210  as illustrated in  FIG. 34B . A nonmagnetic metal film such as a ruthenium oxide tantalum film may be formed in place of the insulating film  203 . 
     For instance, the head elements  12  are made on the insulating film  203  as described in connection with the first embodiment. The head elements  12  are positioned above the grooves  210  with predetermined spaces maintained between them. The grooves  210  are in parallel with one another. Therefore, the head elements  12  are arranged in the shape of matrix on the Al—TiC wafer  61 . The head elements  12  are preferably arranged such that side wall surfaces of the grooves  210  lap over walls of the head elements  12 . If the grooves  210  and the head elements  12  are vertically aligned, the head elements  12  may be formed in an area defined by the grooves  210 . 
     Further, the alumina layer  40  is formed on the insulating film  203  in order to cover the head elements  12 . As illustrated in  FIG. 34C , the piezoelectric devices  101  are bonded on the alumina layer  40  using an Au/Au bonding or the like. The piezoelectric devices are aligned to the head elements  12 . 
     The Al—TiC wafer  61  is cut in rows as illustrated by broken lines, so that a plurality of bars  211  will be made. The piezoelectric devices  101  and the head elements  12  under the piezoelectric devices  101  are arranged in a row along the length of each bar  211  with spaces maintained between them. 
     Referring to  FIG. 34D , cut surfaces (side surfaces) of the bar  211  are machined to make the air bearing surface  11 B of the slider  11 . A length of the reading elements  28  in the head elements  12  will be adjusted. Side walls of each groove  210  are polished together with the reading elements  28 , and the heat resistant resin  202  filled in the groove  210  is exposed on the side surface of the bar  211 , i.e. on the air bearing surface  11 A. The polished groove  210  serves as the groove  201  illustrated in  FIG. 32 . Thereafter, the bar  211  is sliced in the direction orthogonal to its length, thereby obtaining the magnetic heads  200 . 
     In the magnetic head  200 , the piezoelectric device  101  is mounted on the head element  12  and at its peripheral area. As the piezoelectric device  101  expands and contracts, the head element  12  and its peripheral area are perpendicularly displaced with respect to the magnetic disc  3  as illustrated by a broken line in  FIG. 32 . As a result, the sticking amount of the head element  12  varies, which appropriately controls the distance between the head element  12  and the magnetic disc  3 . 
     Displacements of the head elements  12  in the magnetic heads  200  have been simulated. The piezoelectric devices  101  are 500 μm wide, 200 μm high, and 50 μm thick. The piezoelectric devices  101  include ten piezoelectric layers, each of which is 20 μm thick. An applied voltage is 30V. The sticking amount of the head elements  12  becomes 20.8 nm. 
     Properties of the magnetic heads  200  and those of thermally sticking type magnetic heads are evaluated using the floating performance evaluating device. When activated at a low frequency of 1 kHz, the magnetic heads  200  may consume 1/1000 or less power in order to be displaced by an amount which is accomplished by the thermally sticking type magnetic heads. As for frequency characteristics, it is confirmed that the magnetic head  146  can be activated at a frequency which is 100 times higher than a frequency for the thermally sticking type magnetic head. The magnetic heads  146  are very responsive. 
     In this embodiment, the slider  11 , head element  12  and piezoelectric device  101  are arranged in the named order. The head element  12  is displaced by the piezoelectric perpendicular effect of the piezoelectric device  101 , which is effective in shortening the response time. 
     Further, the groove  201  is formed in the head element forming surface  11 A, and has its end exposed above the air bearing surface  11 B, so that the slider  11  does not extensively affect the movement of the head element  12 . This is effective in increasing the displacement of the head element  12  when the piezoelectric device  101  is activated. 
     In the process for manufacturing the magnetic head  200 , the grooves  210  are made before the head elements  12  are made. It is possible to shorten the distance between the grooves  210  and the head elements  12  compared in the case where the grooves  210  are made after the head elements  12  are made. This is effective in facilitating the displacement of the head elements  12 . 
     The grooves  210  are filled with the heat resistant resin  202 , which is effective in protecting the grooves  210  against dust. The use of the heat resistant resin  202  can prevent deterioration caused in a thermal treatment process during the manufacture. 
     Alternatively, after slicing the Al—TiC wafer  61 , the heat resistant resin  202  may be dissolved and be removed from the groove  202 . This extensively alleviates restraint on the movement of the head element  12  exerted by the slider  11 . Therefore, the head element  12  can be more extensively displaced. 
     The magnetic recording device  1  can maintain the constant distance between the head element  12  and magnetic disc  3  with good response, and enables data reading and writing to be carried out in optimum states. 
     The piezoelectric device  41  may be used in place of the piezoelectric device  101 . 
     As well as the groove  201 , a pair of grooves  82  may be made as illustrated in  FIG. 14 . The grooves  82  interleave the piezoelectric device  101  between them. In such a case, the grooves  82  may be made in the semiconductor manufacturing process similarly to the groove  201 . 
     Sixth Embodiment 
       FIG. 35  is a side elevation of a magnetic head  300  of a magnetic recording device according to a sixth embodiment of the invention. 
     Referring to  FIG. 35 , in the magnetic head  300 , the piezoelectric device  41  is mounted on the alumina layer  40  which extends over the head element  12  on the head element forming surface  11 A. As in the first embodiment, the piezoelectric device  41  includes the piezoelectric layer  42  in which thin films are stacked in parallel to the head element forming surface  11 A of the slider  11 . The piezoelectric device  41  expands and contract due to the piezoelectric perpendicular effect, and controls the sticking amount of the head element  12  from the air bearing surface  111 B. 
     The head element  12  is made on the insulating layer  203  as in the first embodiment. The alumina layer  40  covering the head element  12  is formed on the head element forming surface  11 A of the slider  11  via a primary insulating film  302 . 
     With the magnetic head  300 , a groove  301  is formed in the primary insulating film  302 . To be more specific, the groove  302  is a step made on the primary insulating film  302 , is substantially parallel to the head element  12 , and extends across the slider  11 . 
     A depth of the groove  301  is approximately equal to the height of the head element  12 . A bottom of the groove  301  is flush with a lower surface of the primary insulating film  302 . The groove  301  is filled with the heat resistant resin  202  having a low Young&#39;s modulus. A shape and a size of the groove  301 , and a material of the heat resistant resin  202  are similar to those in the fifth embodiment. 
     The magnetic head  300  will be manufactured as follows. 
     Referring to  FIG. 36A , an alumina layer as the primary insulating film  302  is applied on the Al—TiC wafer  61 . The primary insulating film  302  may be made of an insulating material such as silicon oxide (SiO 2 ) except for alumina. However, the alumina layer can be in close contact with alumina used as the insulating film for the head element  12 . 
     Resist patterns are made on the primary insulating film  302 , and a plurality of parallel grooves  310  are made by the ion milling process or reactive plasma etching process. In order to promote the displacement of the head element  12  and improve mechanical strength for supporting the head element  12 , each groove  310  is 30 μm to 150 μm wide, and 0.1 μm to 10 μm deep. Thereafter, the polyimide heat resistant resin  202  or the like is applied on the primary insulating film  302 , fills the grooves  310  completely, and hardens the heat resistant resin  202  as illustrated in  FIG. 36B . 
     Referring to  FIG. 37A , the surface of the Al—TiC wafer  61  is polished by the CMP or the like in order to remove surplus parts of the heat resistant resin  202 . The heat resistant resin  202  remains only in the grooves  310 . 
     Head elements  12  are formed above the grooves  310 . First of all, an alumina insulating film  203  or the like is formed on the primary insulating film  302 , and the heat resistant resin  202  filled in the grooves  310 . A metal film made of a nonmagnetic material may be formed in place of the insulating film  203 . The head elements  12  are formed on the insulating film  203  as described with reference to the first embodiment. 
     The head elements  12  are formed in the shape of a matrix on the Al—TiC wafer  61 . It is preferable that the head elements  12  are aligned to side walls  310 A of the grooves  310 . If the grooves  310  and head elements  12  are vertically aligned, the head elements  12  may be formed at inward positions defined by the grooves  310 . 
     As illustrated in  FIG. 37C , the piezoelectric devices  41  are bonded on the alumina layer  40  in alignment with the head elements  12 . 
     The Al—TiC wafer  61  is cut in rows as illustrated by broken lines, so that a plurality of bars  313  will be obtained. The piezoelectric devices  41  and head elements  12  are arranged in a line along the length of each bar  313  with spaces maintained between them as illustrated in  FIG. 12 . A cut side of the bar  313  is machined to form the air bearing surface  11 B of the slider  11 . A length of the reading element  28  in the head element  12  will be adjusted. In this state, the side walls of the grooves  310  are also polished, so that the heat resistant resin  202  will be exposed on side surfaces of the bar  313 , i.e. on the air bearing surface  11 B. The polished grooves  310  serve as the grooves  301  illustrated in  FIG. 35 . Thereafter, the bars  313  are sliced in the direction orthogonal to the length thereof, so that the magnetic heads  300  will be made. 
     With the magnetic head  300 , as the piezoelectric device  41  expands and contracts, the slider  11  together with the head element  12  is perpendicularly displaced as illustrated by a broken line in  FIG. 35 . Therefore, the sticking amount of the head element  12  varies, which enables the distance between the head element  12  and the magnetic disc  3  to become proper. 
     Displacements of the head elements  12  in the magnetic heads  300  have been simulated. Simulated displacements become nearly a equal to those accomplished in the fifth embodiment. Properties of the head elements  12  and those of sticking type head elements are evaluated using the floating performance evaluating device. Power consumption of the head elements  12  is 1/1000 or less. Further, the head elements  12  can be actuated at a frequency which is 100 times higher than that for thermally sticking type magnetic heads. 
     In this embodiment, the grooves  310  are formed in the insulating layer  203  on the Al—TiC wafer  61 , and the piezoelectric device  141  is mounted near the head element  12 . This embodiment is as effective the fifth embodiment. Especially, the grooves  301  are formed in the very smooth insulating layer  203 , which means that the head element  12  can be made on the very flat surface compared with a case where the groove  301  is formed in the Al—TiC wafer  61 . Further, the machined surface of the grooves  301  becomes very smooth. 
     The piezoelectric device  101  may be used in place of the piezoelectric device  41 . As well as the grooves  301 , a pair of grooves  82  may be made at the opposite sides of the piezoelectric device  101 . The grooves  82  may be made in the semiconductor manufacturing process similarly to the groove  301 . 
     All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a illustrating of the superiority and inferiority of the invention. Although the embodiments of the present inventions have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.