Patent Publication Number: US-7221541-B2

Title: Magnetic head supporting mechanism

Description:
This application is a continuation of application Ser. No. 10/347,290 filed Jan. 21, 2003 now abandoned, which is a division of prior application Ser. No. 09/633,137 filed Aug. 4, 2000 now U.S. Pat. No. 6,560,073, which is a continuation of prior application Ser. No. 08/613,601 filed Mar. 11, 1996 now abandoned, which is a continuation of prior application Ser. No. 08/110,771 filed Aug. 23, 1993 now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a magnetic head supporting mechanism used for a magnetic disk drive. 
     2. Description of the Related Art 
     A magnetic head slider on which a magnetic head is mounted is attached to a free end of a load beam, and is maintained, during a recording/reproducing operation, in a state in which the magnetic head slider flies above a magnetic disk. 
     Recently, it has been required to improve an HDI (Head Disk Interface) characteristic, which is one of the parameters describing the reliability of magnetic disk drives. In order to meet the above requirement, it is necessary to diminish the mass of the magnetic head slider or reduce a spring force urging the magnetic head slider towards the magnetic disk. 
     The following event will occur when the magnetic head slider is diminished. It is necessary to reduce the size of a supporting spring which holds the magnetic head slider as the slider is reduced in size. This is intended to maintain the following characteristic with respect to waviness of the disk and maintain the flying stability of the head. The following event will occur when the spring force on the head slider is reduced. That is, the flying stiffness of the head is degraded due to reduction of the spring force on the head slider. Further, the possibility of assembly errors increases because parts, such as a slider and a supporting spring, are diminished in mass. With the above in mind, it is necessary for a device for supporting a magnetic head slider to have a mechanism capable of sufficiently ensuring the flying stability of the magnetic head slider. 
     Conventionally, the magnetic head supporting mechanism is made up of a load beam, a gimbal fixed to the load beam, and a magnetic head slider fixed to the gimbal. With the above structure, it is more difficult to assemble (position) these parts as the size of the parts is reduced. When there is an assembly error, the magnetic head slider is maintained in an unbalance flying state in which the slider flies in a tilted state. Hence, the reliability of the flying head is degraded and further the read/write characteristics are also degraded. As a result, the reliability of the magnetic disk drive is also degraded. 
     In order to eliminate the factors causing the unbalanced flying due to the assembly error of the head supporting mechanism, Japanese Patent Laid-Open Application No. 3-189976 proposes an improvement in which an integrally formed supporting spring corresponding to the conventional load beam and gimbal is used and assembly is no longer needed. 
       FIG. 1  shows a magnetic head supporting mechanism  1  disclosed in the above application document. The magnetic head supporting mechanism  1  includes a load arm  3  and a load beam  4  (which is also referred to as a flexure). The load beam  4  includes a gimbal  5 , which has openings (through holes)  6  and  7  having a substantially C shape. Further, the gimbal  5  includes a beam  8  supported at both ends in a direction in which the beam  8  traverses the load beam  4 , and tongue portions  9  and  10  extending from the beam  8 . The back surface of the magnetic head slider  11  is formed so that grooves are formed in the width direction of the load beam  4 . 
     The magnetic head slider  11  can be rotated together with a twist of the beam  8  in a pitching direction indicated by an arrow  12 , and can be rotated together with a bend of the beam  8  in a rolling direction indicated by an arrow  13 . 
     It is necessary to reduce the rotation stiffness of the gimbal  5  in order to ensure the flying stability of the compact magnetic head slider. Further, it is impossible to reduce the thickness t of the gimbal  5  having the above structure because the load beam  4  needs to be stiff. In order to reduce the rotation stiffness of the gimbal  5  without reducing the thickness t of the load beam  4 , it is necessary to lengthen the length l of the beam  8 . If the load beam  4  and the gimbal  5  are made to have different thicknesses, it is necessary to a complex process in which only the gimbal  5  is half etched, while the load beam is not processed. However, it is very difficult to obtain a desired precision in thickness by the above process and to obtain desirable characteristics. 
     If the length  1  of the beam  8  is increased, the following disadvantages will occur. First, the resonance point (frequency) of vibration of the twist and bend of the beam  8  becomes lower, and it becomes likely that the degree of flying of the magnetic head slider  11  is varied. Second, the width W of the load beam  4  increases, and hence the resonance frequency of vibration of the load beam  4  itself will becomes lower. Thus, the flying magnetic head slider  11  becomes unstable. 
     Consequently, when the integrally formed supporting spring having the integrated load beam and gimbal is used, it is very difficult to realize a structure of the integrated supporting spring in which only the rotation stiffness is reduced without decreasing the resonance frequency of the gimbal. 
     It becomes impossible to neglect the influence of lead wires connected to the head because of degradation of the air bearing stiffness caused by down-sizing of the slider and reduction in the load force on the head slider. More particularly, the slider is affected by the stiffness of the lead wires and may cause the slider to fly in the tilt state. Particularly, when a magneto-resistive effect type head (MR head) is used as a reproduction head, such a head is combined with an interactive type head. Hence, four lead wires equal to twice the number of lead wires for the conventional recording/reproducing head are needed. Use of the four lead wires increases the influence of the stiffness of the lead wires. This degrades not only the reliability of the flying head but also the read/write characteristics. Hence, the magnetic disk drive does not have satisfactory reliability. 
     SUMMARY OF THE INVENTION 
     It is a general object of the present invention to provide a magnetic head supporting mechanism in which the above disadvantages are eliminated. 
     A more specific object of the present invention is to provide a magnetic head supporting mechanism capable of stably maintaining a magnetic head slider in the flying state. 
     The above objects of the present invention are achieved by a magnetic head supporting mechanism comprising: a head positioning actuator ( 223 ) having an arm ( 22 ); and a load beam ( 21 ) connected to said arm. The load beam has a gimbal ( 25 ) comprising: a magnetic head slider fixing portion ( 30 ) on which a magnetic head slider ( 35 ) having a magnetic head is mounted; a first pair of beams ( 31 ,  32 ) extending from opposite sides of the magnetic head slider fixing portion along a traverse direction ( 38 ) of the load beam perpendicular to a longitudinal direction ( 37 ) thereof; and a second pair of beams ( 33 ,  34 ) respectively connected to the first pair of beams and extending along said opposite sides of the magnetic head slider fixing portion. 
     In an alternative, the first pair of beams extends in the longitudinal direction, and the second pair of beams extends in the traverse direction. 
     The above objects of the present invention are also achieved by a magnetic head supporting mechanism comprising: a head positioning actuator ( 223 ) having an arm ( 22 ); and a load beam ( 21 ) connected to said arm. The load beam having a gimbal ( 51 ) comprises: a magnetic head slider fixing portion ( 30 ) on which a magnetic head slider ( 35 ) having a magnetic head is mounted; a first pair of beams ( 31 ,  32 ) extending from opposite sides of the magnetic head slider fixing portion along a longitudinal direction of the load beam perpendicular to a traverse direction thereof; and a second pair of beams ( 33 ,  34 ) respectively connected to the first pair of beams and extending along said opposite sides of the magnetic head slider fixing portion. 
     Another object of the present invention is to provide a magnetic disk drive having the above-mentioned magnetic head supporting mechanism. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a conventional magnetic head supporting mechanism; 
         FIG. 2  is a perspective view of a magnetic head supporting mechanism according to a first embodiment of the present invention; 
         FIG. 3  is a plan view of a 3.5-inch magnetic disk drive to which the magnetic head supporting mechanism shown in  FIG. 2  is applied; 
         FIG. 4  is a perspective view of a first-order bend state of a load beam shown in  FIG. 2 ; 
         FIG. 5  is a perspective view of a first-order twist state of the load beam shown in  FIG. 2 ; 
         FIG. 6  is a perspective view of the upper side of the magnetic head supporting mechanism shown in  FIG. 2 ; 
         FIG. 7  is a side view of the magnetic head supporting mechanism shown in  FIG. 2 ; 
         FIG. 8  is a perspective view of a magnetic head supporting mechanism according to a second embodiment of the present invention; 
         FIG. 9  is a perspective view of a magnetic head supporting mechanism according to a third embodiment of the present invention; 
         FIG. 10  is a perspective view of a magnetic head supporting mechanism according to a fourth embodiment of the present invention; 
         FIG. 11  is a side view of the mechanism shown in  FIG. 10 ; 
         FIG. 12  is a perspective view of a magnetic head supporting mechanism according to a fifth embodiment of the present invention; 
         FIG. 13  is a perspective view of a magnetic head supporting mechanism according to a sixth embodiment of the present invention; 
         FIG. 14  is a plan view of a free-end part of a load beam shown in  FIG. 13 ; 
         FIG. 15  is a sectional-view taken along a line XIV—XIV shown in  FIG. 13 ; 
         FIG. 16  is a perspective view of a magnetic head slider shown in  FIG. 13 ; 
         FIG. 17  is a flowchart of a production process for the load beam shown in  FIG. 13 ; 
         FIG. 18  is a plan view of a plate obtained after an etching step shown in  FIG. 17  is carried out; 
         FIG. 19  is a flowchart of another production process for the load beam shown in  FIG. 13 ; 
         FIG. 20  is a perspective view of a variation of the sixth embodiment of the present invention; 
         FIG. 21  is a perspective view of a magnetic head supporting mechanism according to a seventh embodiment of the present invention; 
         FIG. 22  is a plan view of a magnetic disk drive to which the magnetic head supporting mechanism shown in  FIG. 21  is applied; 
         FIGS. 23A and 23B  are respectively plan and side views of the magnetic head supporting mechanism shown in  FIG. 21 ; 
         FIG. 24  is a side view of a state observed when the magnetic head supporting mechanism shown in  FIG. 21  is provided in the magnetic disk drive; 
         FIG. 25  is an emphasized view of the state in  FIG. 24 ; 
         FIG. 26  is a side view of a first-order bend state of a load beam used in the seventh embodiment of the present invention; 
         FIG. 27  is a side view of a first-order twist state of the load beam used in the seventh embodiment of the present invention; 
         FIG. 28  is a plan view of a first variation of a gimbal of the load beam used in the seventh embodiment of the present invention; 
         FIG. 29  is a plan view of a second variation of the gimbal of the load beam used in the seventh embodiment of the present invention; 
         FIG. 30  is a plan view of a third variation of the gimbal of the load beam used in the seventh embodiment of the present invention; 
         FIG. 31  is a plan view of a fourth variation of the gimbal of the load beam used in the seventh embodiment of the present invention; 
         FIG. 32  is a plan view of a fifth variation of the gimbal of the load beam used in the seventh embodiment of the present invention; and 
         FIG. 33  is a side view of a variation of the seventh embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A description will now be given, with reference to  FIG. 2 , of a magnetic head supporting mechanism  20  according to a first embodiment of the present invention. 
       FIG. 3  shows a 3.5-inch type magnetic disk drive  220  to which the magnetic head supporting mechanism  20  is applied. The magnetic disk drive  220  has an enclosure  221  in which a 3.5-inch magnetic disk  222 , a head positioning actuator  223  and other parts are housed. 
     A load beam  21  made of stainless steel is fixed to an arm  22  of the actuator  223 . The load beam  21  has a curved bent portion  23  generating elasticity. In this regard, the curved portion  23  of the load beam  21  is also referred to as an elastic portion  23  in the following description. The load beam  21  has a stiffness portion  24  extending from the elastic portion  23 , and ribs  21   a . The elastic portion  23  provides a magnetic head slider  35  with a load in a direction in which the magnetic head slider  35  moves and comes into contact with a magnetic disk  222 . The load beam  21  has a uniform thickness of, for example, approximately 25 μm, which is equal to one-third of the thickness of a load beam of a 3380-type (IBM) head supporting mechanism. 
     It is desirable that the width W 1  of the load beam  21  is made as small as possible, desirably 4 mm or less. This is because the resonance frequency of vibration of the load beam  21  is prevented from lowering. 
     A gimbal  25  is formed in the load beam  21 . The gimbal  25  includes a pair of C-shaped openings  26  and  26  facing each other in the longitudinal direction of the load beam  21 . Two slits  28  and  29  are formed in the load beam  21  along respective sides of the load beam  21 . 
     The gimbal  25  includes a magnetic slider fixing portion  30 , a first pair of beam portions  31  and  32 , and a second pair of beam portions  33  and  34 . The magnetic head slider fixing portion  30  has large surface dimensions enough to fix the magnetic head slider  35  thereon, and has the same dimensions as the magnetic head slider  35  (a=1.6 mm, b=2.0 mm). However, it is possible for the slider fixing portion  30  to have an area less than the magnetic head slider  35  when a sufficient adhesive strength can be obtained. 
     The magnetic head slider  35  is a light weight structure type slider, which has been proposed in Japanese Patent Laid-Open Application No. 4-228157. The proposed slider has a flat back surface opposite to a disk facing surface. The flat back surface of the slider is fixed to the fixing portion  30  by means of an adhesive. In this case, the slider  35  is located so that the center thereof corresponds to the center of the fixing portion  30 . It is also possible to use other types of sliders. 
     The beam portions  33  extends from the beam portion  31  towards the respective sides of the beam portion  31  so that the beam portion  33  crossed the beam portion  31  at a right angle and extends in parallel with the lines  37 . Similarly, the beam portion  34  extends from the beam portion  32  towards the respective sides of the beam portion  32  so that the beam portion  34  crosses the beam portion  32  at a right angle and extends parallel to the lines  37 . The beam portion  33  is joined to portions  40  and  41  of the load beam  21  in the periphery of the gimbal  25 . Similarly, the beam portion  34  is joined to portions  42  and  43  of the load beam  21  in the periphery of the gimbal  24 . In other words, the beam portion  33  extends from the portion  40  and  41  of the gimbal  25 , and the beam portion  34  extends from the portions  42  and  43  of the gimbal  24 . The distance between the center of the beam portion  33  and one of the two ends thereof is  1   2 . Similarly, the distance between the center of the beam portion  34  and one of the two ends thereof is also  1   2 . 
     The beam portion  33  extends from the beam portion  31  towards the respective sides of the beam portion  31  so that the beam portion  33  crosses the beam portion  31  at a right angle and extends in parallel with the line  37 . Similarly, the beam portion  34  extends from the beam portion  32  towards the respective sides of the beam portion  32  so that the beam portion  34  crosses the beam portion  32  at a right angle and extends in parallel with the line  37 . The beam portion  33  is joined to portions  40  and  41  of the load beam  21  in the periphery of the gimbal  25 . Similarly, the beam portion  34  is joined to portions  42  and  43  of the load beam  21  in the periphery of the gimbal  25 . In other words, the beam portion  33  extends from the portions  40  and  41  of the gimbal  25 , and the beam portion  34  extends from the portions  42  and  43  of the gimbal  25 . The distance between the center of the beam portion  33  and one of the two ends thereof is  1   2 . Similarly, the distance between the center of the beam portion  34  and one of the two ends thereof is also  1   2 . 
     The beam portion  33  and the beam portion  31  form a T-shaped beam  39 A. Similarly, the beam portion  34  and the beam portion  32  form a T-shaped beam  39 B. The beam portions  31 ,  32 ,  33  and  34  form an H-shaped beam. It will be noted that the fixing portion  30 , the first pair of beams  31  and  32 , and the second pair of beams  33  and  34  are portions of the load beam  21 . 
     The length  1   1  of the first pair of beams  31  and  32  is limited by the width W 1  of the load beam  21 . As the width W 1  of the load beam  21  is increased, the resonance frequency of a bend and twist of the load beam  21  becomes lower, and the flying characteristics of the slider  35  are degraded. For these reasons, the width W 1  cannot be increased. However, according to the first embodiment of the present invention, it is possible to increase the length  1   2  of the second pair of beams  33  and  34  without being limited by the width W 1  of the load beam  21 . The second pair of beams  33  and  34  is formed so that  1   2 &gt; 1   1 . That is, each of the T-shaped beams  39 A and  39 B has a leg portion and an arm portion longer than the leg portion. 
     When a waviness of the magnetic disk being rotated is present or dust adheres to the magnetic disk, the magnetic head slider  35  is rotated in a pitching direction indicated by an arrow  44  in a state in which the first pair of beams  31  and  32  and the second pair of beams  33  and  34  are bent. At this time, a twist deformation occurs in the first pair of beams  31  and  32  of the gimbal  24 , and a bend deformation occurs in the second pair of beams  33  and  34 . 
     As indicated by an arrow  45 , the magnetic head slider  35  is rotated in a rolling direction also. At this time, bend deformations occur in the beams  31  and  32  in the respective directions opposite to each other, and bend deformations occur in the beams  33  and  34  in the respective directions opposite to each other. 
       FIG. 4  shows a resonance mode of the first-order bend. A deformation occurs in the elastic portion  23  formed at the root of the load beam  21 , and the first pair of beams  31  and  32  and the second pair of beams  33  and  34  are deformed in the same direction. 
       FIG. 5  shows a resonance mode of the first-order twist. A twist deformation occurs in the elastic portion  23  formed at the root of the load beam  21  in such a manner so the right and left portions of the elastic portion  23  have different heights. The beam located on the right side of the gimbal  25  is deformed so as to be formed into a convex shape facing upwards. The beam located on the left side of the gimbal  25  is deformed so as to be shaped into a convex facing downwards. When the lengths  1   1  and  1   2  are selected so that the length  1   2  is equal to three or four times the length  1   1 , the rotation stiffness responses of the slider in the pitching and rolling directions become sufficiently soft and are almost the same as each other. 
     As shown in  FIG. 2 , a composite type magnetic head  48  and four terminals  10 A,  100 B,  100 C and  100 D are provided in the magnetic head slider  35 . The magnetic head  48  includes an MR head for reproduction and an interactive type head for recording, these heads being integrated with each other. The magnetic head  48  is located at a rear end surface of the magnetic head slider  35  in a relative movement direction  46  with respect to the magnetic disk  222 . 
     As shown in  FIGS. 6 and 7 , lead wires  15 A,  15 B,  15 C and  15 D are connected to the terminals  100 A,  100 B,  100 C and  100 D, respectively. Each of the lead wires  15 A through  15 D has a diameter of, for example, 30 μm. The lead wires  15 A– 15 D are laid on the side opposite to the side on which the magnetic head slider  35  is mounted, and are attached to a center portion  36  of the fixing portion  30  by means of an adhesive  16 . Further, the lead wires  15 A– 15 D extend along the longitudinal center line  37  of the load beam  21  towards the base portion of the load beam  21 , and are fixed thereto at two points by means of the adhesive  16 . 
     Reference numbers  17   −1 ,  17   −2  and  17   −3  respectively indicate a first fixing point, a second fixing point and a third fixing point at which the lead wires  15 A through  15 D are fixed by means of the adhesive  16 . The first fixing point  17   −1  moves in accordance with movement of the magnetic head slider  35 . Hence, it is unnecessary to be concerned about the stiffness of portions of lead wires  15 A through  15 D between the terminals  100 A– 100 D and the first fixing point  17   −1  and to provide additional lengths of the lead wires  15 A– 15 D. In  FIG. 6 , such additional lengths of the lead wires  15 A– 15 D are not provided. The distance between the first fixing point  17   −1  and the second fixing point  17   −2  is long, and the stiffness of the lead wires  15 A– 15 B between the fixing points  17   −1  and  17   −2  little affects the rotation stiffness of the gimbal  25 . 
     The magnetic head supporting mechanism  20  has the following features. First, the rotation stiffness of the gimbal  25  is considerably small because of the characteristics of the T-shaped beams. Second, the gimbal  25  is supported at the four points  40 – 43 , and hence, the resonance frequency of vibration of the gimbal  25  is high even when the second pair of beams  33  and  34  is long. Third, the end of the load beam  21  can be formed so that it has a small width W 1 , and hence the resonance frequency of vibration of the load beam  21  is high. Fourth, the flying stability of the magnetic head slider  35  is excellent due to the above first, second and third features. The fifth feature of the mechanism  20  is such that the first pair of beams  31  and  32  has a short length  1   1  and is formed in the same plane. Hence, the first pair of beams  31  and  32  has a large strength with respect to force received in the contact start/stop operation, and a shear failure does not easily occur in the beams  31  and  32 . The sixth feature of the mechanism  20  is such that the stiffness of the lead wires  15 A– 15 D does not affect the rotation stiffness of the gimbal  25 . 
     As has been described above, the gimbal  25  is formed so that a pair of T-shaped beams (which form an H-shaped beam) is provided with respect to the center of the gimbal  25 , and hence a low rotation stiffness and a high resonance frequency are achieved. More specifically, the rotation stiffness of the mechanism  20  becomes one-third of that of the aforementioned IBM 3380 type head supporting mechanism, while the resonance frequency of the mechanism  20  is as high as that of the IBM 3380 type head supporting mechanism. As a result, it becomes possible to stably fly a compact slider having a low air bearing stiffness. 
     Tables 1 and 2 show characteristics of the head supporting mechanism  20  according to the first embodiment of the present invention supporting a 2 mm-length slider, and the IBM 3380 type head supporting mechanism supporting which a 3.2 mm-length slider. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 COMPARISON OF STIFFNESS 
               
               
                 (static characteristics by computer simulation) 
               
            
           
           
               
               
               
               
            
               
                   
                 Stiffness 
                 1st embodiment 
                 3380 type 
               
               
                   
                   
               
               
                   
                 pitch stiffness 
                  1.5 grf cm/rad 
                 9.4 grf cm/rad 
               
               
                   
                 roll stiffness 
                  1.5 grf cm/rad 
                 5.1 grf cm/rad 
               
               
                   
                 up/down stiffness 
                 0.55 grf/mm 
                 2.4 grf/mm 
               
               
                   
                 equivalent weight ratio 
                 0.74 
                 0.72 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 COMPARISON OF RESONANCE FREQUENCY 
               
               
                 (dynamic characteristic by computer simulation) 
               
            
           
           
               
               
               
               
            
               
                   
                 Stiffness 
                 1st embodiment 
                 3380 type 
               
               
                   
                   
               
               
                   
                 1st bend 
                 2.1 kHz 
                 2.1 kHz 
               
               
                   
                 1st twist 
                 2.3 kHz 
                 2.6 kHz 
               
               
                   
                 in-plane 
                 8.5 kHz 
                 5.7 kHz 
               
               
                   
                   
               
            
           
         
       
     
     In order to make the equivalent weight ratio ((supporting spring equivalent weight)/(slider weight) of the first embodiment equal to that of the IBM 3380 type mechanism, the total length of the supporting mechanism is short (10 mm), which is approximately half of that of the IBM 3380 type mechanism. Further, the thickness of the load beam  21  of the first embodiment is 25 μm, which is approximately one-third of that of the IBM 3380 type mechanism. 
     Table 1 shows data obtained by computer simulation. More specifically, Table 1 shows the pitch stiffness and roll stiffness of the gimbal  25  of the first embodiment, and the up/down stiffness of the load beam  21  thereof. Further, Table 1 shows the pitch stiffness and the roll stiffness of the gimbal of the IBM 3380 type mechanism, and the up/down stiffness of the load beam thereof. It can be seen from Table 1 that the rotation stiffness equal to one-third of the gimbal of the IBM 3380 type mechanism can be obtained by optimizing the width and length of the grooves in the gimbal  25 . 
     Table 2 shows the resonance frequencies of the first embodiment and the conventional IBM 3380 type mechanism obtained by a computer simulation. The resonance frequencies of the first embodiment are similar to those of the IBM 3380 type mechanism. 
     As will be seen from the above, the magnetic head supporting mechanism according to the first embodiment of the present invention has a low stiffness and a high resonance frequency. 
     A description will now be given of a second embodiment of the present invention. In the following description, parts that are the same as those shown in  FIG. 2  are given the same reference numbers. 
       FIG. 8  shows a magnetic head supporting mechanism  50  according to the second embodiment of the present invention. The mechanism  50  includes a gimbal  51 . The gimbal  51  is formed so that the gimbal  25  shown in  FIG. 2  is rotated about the center  36  by 90°. Two T-shaped beams  52  and  53  are arranged in the longitudinal direction of the load beam  21 . 
       FIG. 9  shows a magnetic head supporting mechanism  60  having a gimbal  61  according to a third embodiment of the present invention. The gimbal  61  has the aforementioned first pair of beams  31  and  32 , and a second pair of beams  33 A and  34 A. The beam  33 A and the beam  31  form an acute angle α. Similarly, the beam  34 A and the beam  32  form an acute angle equal to the acute angle α. With the above structure, it becomes possible to form, without increasing the width W 1  of the load beam  21 , the second pair of beams  33 A and  34 A so that the length 2× 1   2a  thereof is greater than the length 2× 1   2  of the second pair of beams  33  and  34  shown in  FIG. 2 . Further, it is possible to narrow the end of the load beam  21 . Hence, the rotation stiffness of the gimbal  61  is less than that of the gimbal  25  shown in  FIG. 2 . Thus, the magnetic head slider  35  in the third embodiment can be more stably flied than that in the first embodiment shown in  FIG. 2 . 
       FIG. 10  shows a magnetic head supporting mechanism  70  having a gimbal  71  according to a fourth embodiment of the present invention. A magnetic head slider  35 A of the mechanism  70  includes flanges  72  and  73  formed on the respective sides of the slider  35 A. A magnetic head slider fixing portion  30 A of the gimbal  71  includes an opening  74  having a size corresponding to the magnetic head slider  35 A. The opening  74  is of a rectangular shape defined by a rectangular frame  76 . As shown in  FIG. 10 , the magnetic head slider  35 A engages the opening  74 , and the flanges  72  and  73  are made to adhere to the frame  76  by means of an adhesive. In this manner, the magnetic head slider  35 A is fixed to the magnetic head slider fixing portion  30 A. 
     As shown in  FIG. 11 , the center G of gravity of the magnetic head slider  35 A is substantially located on the surface of the load beam  21 . Hence, in a seek operation, the magnetic head slider  35 A is moved by exerting a force on the center G of gravity. Thus, an unnecessary rotation force about the center G of gravity of the magnetic head slider  35 A does not occur, and the unbalance of the magnetic head slider  35 A is reduced. As a result, the magnetic head slider  35 A can stably flied in the seek operation. 
     Further, the height of the magnetic head assembly can be reduced. Hence, it is possible to laminate layers of the head at reduced intervals and to provide an increased number of disks per unit length. As a result, it is possible to increase the volume storage density of the magnetic disk drive and hence the storage density. 
       FIG. 12  shows a magnetic head supporting mechanism  80  having a magnetic head slider  35 B according to a fifth embodiment of the present invention. The magnetic head slider  35 B has a flange  81  formed around the circumference thereof. The magnetic head slider  35 B engages the opening  74 , and the flange  81  is made to adhere to the magnetic head slider fixing portion  30 A by means of an adhesive. That is, the fifth embodiment of the present invention differs from the fourth embodiment thereof in that the whole circumference of the magnetic head slider  35 B is made to adhere to the fixing portion  30 A. Hence, the adhesive strength is increased and the reliability of the magnetic head supporting mechanism is improved. 
       FIG. 13  shows a magnetic head supporting mechanism  90  according to a sixth embodiment of the present invention.  FIG. 14  shows a free end of a load beam of the magnetic head supporting mechanism  90 . The mechanism  90  is designed so that it does not have any influence of the stiffness of lead wires, which affect flying of the slider having a low air bearing stiffness. For example, when, in the case where four lead wires are connected between the slider and the load beam (see  FIG. 6 ), each of the lead wires has a diameter of 30 μm and has an additional length (free length) of 1 mm, the rotation stiffness of the gimbal is approximately five times that of the gimbal in which there is no lead wire. This degrades the flying stability of the slider. 
     The magnetic head supporting mechanism  90  has wiring patterns  91 ,  92 ,  93  and  94 , which are formed by patterning a copper thin film formed by, for example, plating by means of the photolithography technique. The wiring patterns  91 – 94  extend on a central portion of the lower surface of the load beam  21  in the longitudinal direction. Each of the wiring patterns  91 – 94  is approximately 5 μm thick and 50 μm wide. The thickness and width of the wiring patterns depend on the resistance of the conductive pattern and the capacity of the load beam  21 . 
     Terminals  95 A– 95 D made of copper are formed on the base portion of the load beam  21 . Further, terminals  96 A– 96 D are formed in a terminal area  30   a  of the magnetic head slider fixing portion  30  of the gimbal  25 . The tops of the terminals  95 A– 95 D and  96 A– 96 D are plated by, for example, Au. This plating contributes to preventing exposure of copper and improving the bonding performance. Ends of the wiring patterns  91 ,  92 ,  93  and  94  are respectively connected to the terminals  95 A,  95 B,  95 C and  95 D. The other ends of the two wiring patterns  91  and  92  extend along the beams  33 A and  31 , and are connected to the terminals  96 A and  96 B, respectively. The other ends of the wiring patterns  93  and  94  extend along the beams  34 A and  32  and are connected to the terminals  96 C and  96 D, respectively. 
     As shown in  FIG. 15 , the wiring patterns  91 ,  92 ,  93  and  94  are electrically insulated from the load beam  21  by means of an insulating film  97 , and are covered by a protection film  98 . The insulating film  97  and the protection film  98  are made of photosensitive polyimide and are grown to a thickness of approximately 5 μm. The insulating film  97  and the protection film  98  are respectively patterned by the photolithography technique. The thickness of the insulating film  97  is determined on the basis of a capacitance between the conductive pattern (made of Cu) and the load beam (made of stainless steel). 
     As will be described later, polyimide has heat-resistance enough for an annealing process. Since polyimide has photosensitivity, it can be easily patterned. Further, the polyimide films  97  and  98  have corrosion resistance, and excellent reliability. 
     It is likely that the terminals  95 A– 95 D and  96 A– 96 D are etched because these terminals are not covered by the protection film  98 . In order to prevent the terminals  95 A– 95 D and  96 A– 96 D from being etched, the surfaces of these terminals are covered by an Au film (not shown) having a thickness of approximately 1 μm formed by plating or vapor deposition. 
     As shown in  FIG. 16 , the magnetic head slider  35  is adhered to the fixing portion  30  by means of an adhesive. The terminals  96 A– 96 D are located at a right angle with respect to terminals  100 A– 100 D of the magnetic head  48  formed on the end surface of the magnetic head slider  35 , and are respectively connected to the terminals  100 A– 100 D by means of Au balls  101 A– 101 D. The Au balls  101 A– 101 D are formed by means of, for example, a gold ball bonding device. In order to facilitate bonding, the terminals  96 A– 96 D and terminals  100 A– 100 D are located as shown in  FIG. 16 . In order to facilitate a crimp operation on the Au balls  101 A– 101 D, the terminals  100 A– 100 D are long in the direction of the height of the magnetic head slider  35  and are located so that these terminals  100 A– 100 D face the terminals  96 A– 96 D in the state where the head slider  35  is fixed to the fixing portion  30 . 
     The wiring patterns  91 – 94  bypass holes  102 A,  102 B and  102 C, as shown in  FIG. 13  and extend up to an area close to the head slider  35 . The hole  102 C is used to fix the load beam  21  to the arm  22  (not shown in  FIG. 13 ). The holes  102 A,  102 B and  102 C are sized such that a tool can be inserted therein. 
     As shown in  FIGS. 13 and 14 , dummy patterns  103 A– 103 D and  104 A– 104 D are provided so that these dummy patterns are symmetrical to the bypassing portions of the wiring patterns  91 – 94  with respect to the holes  102 A and  102 B. The insulating film  97  and the protection film  98  are provided for the dummy patterns  103 A– 103 D and  104 A– 104 D in the same manner as the wiring patterns  91 – 94 . The dummy patterns  103 A– 103 D and  104 A– 104 D are provided in order to balance the mechanical stiffness of the load beam  21  in the direction of the width of the load beam  21 . 
     As shown in  FIG. 14 , the wiring patterns  91 – 94  are arranged so that these patterns form a loop. This loop functions as an antenna, which receives noise components contained in the head signals. As the size of the loop is increased, the degree of the nose components is increased. In order to reduce the loop, the wiring patterns  91  and  92  respectively connected to the terminals  96 A and  96 B are arranged between the hole  102 A and the magnetic head slider  35 , and all the wiring patterns  91 – 94  are gathered in the vicinity of the hole  102 A. In order to balance the stiffness in the direction of the width of the load beam, the dummy patterns  104 A– 104 D are formed. For the same reason as above, the dummy patterns  103 A– 103 D are formed in the vicinity of the hole  102 B. 
     As shown in  FIG. 14 , auxiliary films  106  and  107  having a belt shape are formed along the right and left ends of the load beam  21 . The auxiliary films  106  and  107  are provided in order to receive a clamping force generated when the load beam  21  is clamped in a bending process which will be described later. Such a clamping force is also received by the wiring patterns  91 – 94 . The clamping force is distributed so that the clamping force is exerted on not only the wiring patterns  91 – 94  but also the auxiliary films  106  and  107 . Hence, it is possible to prevent the wiring patterns  91 – 94  from being damaged. 
     As shown in  FIGS. 13 and 14 , a convex dummy pattern  108  is provided in order to prevent an adhesive from flowing from the fixing portion  30  when the slider  35  is fixed to the fixing portion  30  and to prevent the slider  35  from being tilted due to the thickness of the wiring patterns. More particularly, the convex pattern  108  is used to form a groove in which adhesive used to fix the slider  35  is saved between the pattern  108  and the terminals  96 A– 96 D. Further, the convex pattern  108  is designed to have the same height as the patterns having the terminals  96 A– 96 D. If the dummy pattern  108  is not used, the slider  35  will be inclined with respect to the fixing portion  30  due to the height of the terminals  94 A– 94 D. This degrades the flying stability of the heads. The convex pattern  108  can be formed by a cooper-plated thin film similar to the wiring patterns  91 – 94 . The protection film  98  covers the convex pattern  108 . The adhesive is provided on a step part between the wiring patterns and the convex pattern  108 . 
     The load beam  21  is produced by a process shown in  FIG. 17 . First, a pattern formation step  110  is performed. More particularly, photosensitive polyimide is coated on a stainless plate. The insulating film  97  is formed by the photolithography technique. A copper film is formed by the plating process, the vapor deposition process or the like, and is patterned into the wiring patterns  91 – 94  by the photolithography technique. Thereafter, photosensitive polyimide is coated and is patterned into the protection film  98  and the auxiliary films  106  and  107  by the photolithography technique. Polyimide can be coated by a spin-coat process, and is patterned and etched. A thin film, such as a Cr film can be in order to improve the adhesiveness between the insulating film and the Cu film and between the Cu film and the protection film and to improve the reliability of the adhesion. 
     Next, an etching step  111  is performed in order to form the openings  26 – 29  and the holes  102 A– 102 C and the outward form of the load beam in the stainless plate.  FIG. 18  shows load beams  202  before punching for cutting off bridge portions (not shown) to provide pieces, so that the load beams  202  are formed in a stainless plate  201  and arranged in rows and columns. 
     Then, a bending step  112  is performed by bending the respective ends of each of the load beams  202  formed in the stainless plate  201 , so that ribs  21   a  are formed. The bending step  112  can be performed by press so that the load beams  202  are processed at the same time. 
     Finally, an annealing step  113  is performed at a temperature of approximately 400° C., so that internal stress can be removed. Further, a slider adhering step and an Au bonding step can be automatically carried out before the load beams  202  are punched. Hence, it is possible to automatically perform the production process shown in  FIG. 17  and reduce the number of steps and the cost thereof. 
     The load beam  21  can be produced without performing the annealing step  113 . In this case, as is shown in  FIG. 19 , the pattern formation step  110  and the etching step  111  are performed, and subsequently the slider adhering step and the Au bonding step are carried out. Thereafter, the bending step  112  is carried out to form the ribs  21   a.    
     As shown in  FIG. 20 , when interactive type heads  48 A and  48 B for recording and reproduction are used as magnetic heads, the magnetic head slider  35  has the aforementioned two terminals  100 A and  100 B. In the gimbal  25 , the two wiring patterns  91 A and  92 A are provided so that these wiring patterns extend on only the beams  32  and  34 A, while two dummy patterns  210  and  211  are provided so as to extend on the beam  31  and  33 A in order to balance the mechanical stiffness of the load beam  21  in the direction of the width of the load beam  21 . 
     The magnetic head supporting mechanism  90  has the following features. 
     First, since the wiring patterns  91 – 94  are formed on the load beam  21 , it is not necessary to provide tubes for passing the lead wires through the load beam  21 . Hence, it is possible to prevent unbalanced force caused by the lead wires and tubes from being exerted on the magnetic head slider  35  and to stably fly the magnetic head slider  35 . 
     Second, due to use of the dummy patterns  103 A– 103 D and  104 A– 104 D, the rotation stiffness of the load beam  21  does not have polarity. Hence, the magnetic head slider can fly stably. 
     Third, the crimp connection using the Au balls  101 A– 101 D enables automatic assembly and non-bire bonding between head terminals and pattern terminals. 
     In the aforementioned embodiments of the present invention, the beams may be curved. 
     A description will now be given of a magnetic head supporting mechanism suitable for a more compact magnetic disk drive according to a seventh embodiment of the present invention. 
       FIG. 21  shows a back surface of a magnetic head supporting mechanism  230  according to the seventh embodiment of the present invention.  FIG. 22  shows a 1.8-inch-type magnetic disk drive  231  to which the magnetic head supporting mechanism  230  is applied. 
     The magnetic disk drive  231  has an enclosure  232  having almost the same dimensions as those of an IC memory card. In the enclosure  232 , provided are a magnetic disk  233  having a diameter of 1.8 inches, and an actuator to which two sets of magnetic head supporting mechanisms are attached. The magnetic disk drive  231  is more compact than the magnetic disk drive  220  shown in  FIG. 3 . 
     A magnetic head slider  35 C is made compact in accordance with light-sizing of the magnetic disk drive  231 . More particularly, dimensions a×b of the magnetic head slider  35 C are 0.8 mm×1.0 mm, and are approximately one-quarter the area of the magnetic head slider  35  shown in  FIG. 2 . In order to stably fly the compact magnetic head slider  35 C, it is necessary to considerably reduce the stiffness without decreasing the resonance frequency, as compared with the magnetic head supporting mechanism  30 . 
     A load beam  235  shown in  FIG. 21  is made of stainless, and has a base portion fixed to an arm  236  of the actuator  234  (see  FIG. 22 ). The load beam  235  has a width W 2  of approximately 2 mm, a length L of approximately 9 mm, and a thickness to of approximately 25 μm, and is approximately a half of the volume of the load beam  21  shown in  FIG. 2 . The load beam  235  is diminished, and hence the resonance frequency of bending which will be described later is high. 
     The load beam  235  is a sheet-shaped piece, and a flat plate piece to which a bending process has not been subjected. Hence, there is no problem of a bending process error which degrades the flying stability of the magnetic head slider. The load beam  235  includes a load beam main body  237  and a gimbal  238  located on the end side of the load beam  235 . The gimbal  238  has a substantially U-shaped opening (through hole)  239  formed in the load beam  235 . The gimbal  238  includes a magnetic head slider fixing portion  240 , a first beam  241 , a second beam  242 , a third beam  244 , and a connecting portion  243 . 
     The magnetic head slider fixing portion  240  has a size corresponding to the magnetic head slider  35 C. The first beam  241  and the second beam  242  extend along respective longitudinal ends of the load beam  235  from the end thereof. The connecting portion  243  extends in the direction of the width of the load beam  235 , and connects the first beam  241  and the second beam  242  together. The third beam  244  extends from the connecting portion  243  to the magnetic head slider fixing portion  240  in the longitudinal direction of the load beam  235 . The magnetic head slider fixing portion  240  is connected to the main body  237  of the load beam  235  via the third beam  244 , the connecting portion  243  and the first and second beams  241  and  242 . Hence, the rotation stiffness of the load beam  230  can be reduced to a small value due to bending of the entire beams. 
     As shown in  FIG. 21 , holes  245 ,  246  and  247  with which a tool is engaged, and a pair of slits  248  and  249  are formed in the main body  237  of the load beam  235 . Adjustment slits  248  and  249  are used to reduce the rotation stiffness of the load beam. The holes  245 ,  246  and  247  and the slits  248  and  249  are formed by etching. The connectors  95 A– 95 D,  96 A– 96 D and the wiring patterns  91 – 94  are formed symmetrically with respect to the longitudinal direction of the load beam  235 . The magnetic head slider  35 C is made to adhere to the fixing portion  240 , and the terminals  96 A– 96 D and  100 A– 100 D are respectively connected to each other by means of Au balls as in the case shown in  FIG. 16 . 
     The structure shown in  FIG. 21  does not use dummy patterns because the length and the width of the load beam  235  are less than those of the load beam shown in  FIG. 13  and the loop formed by the wiring patterns is smaller than that shown in  FIG. 13 . However, it is preferable to arrange the wiring patterns and provide the dummy patterns as shown in  FIGS. 13 and 14  in order to reduce the noise from the heads. 
     As shown in  FIGS. 23A and 23B , the free end of the arm  236  is bent so that a substantially V-shaped cross section of the arm  236  is formed in which the “V” is inverted. The free end of the arm  236  has an upward slant portion  236   a  and a downward slant portion  236   b  declined at an angle θ with respect to the horizontal direction. 
     The magnetic disk drive  231  uses two magnetic head supporting mechanisms  230  so that the single magnetic disk  233  is sandwiched between the mechanisms  230 . As shown in  FIG. 24 , the load beam  235  causes the magnetic head slider  35 C to come into contact with the magnetic disk  233  when the magnetic disk  233  is not being rotated. At this time, the main body  237  of the load beam  235  is caused to be bent and elastically deformed. The elastic force stored in the main body  237  of the load beam  235  generates a load F 1 , which urges the magnetic head slider  35 C towards the magnetic disk  233 . 
     Since the arm  236  is bent in the form of the inverted “V”, a wide gap  250  can be formed between an end  236   c  of the arm  236  and the magnetic disk  233 , as compared with a case indicated by a two-dot chained line in which the arm  236  is simply bent downwards. 
     A description will now be given of a moment exerted on the magnetic head slider  35 C by means of the load beam  235  when the load beam is loaded on the disk. As shown in  FIG. 25 , the main body  237  of the load beam  235  and the third beam  244  are bent. Hence, a moment is exerted by a center  251  of the magnetic head slider  35 C. A moment M 1  directed counterclockwise is exerted by the load beam main body  237  and the first and second beams  241  and  242 . A moment M 2  directed clockwise is exerted on the third beam  244 . The dimensions of the load beam  235  are selected so that the moments M 1  and M 2  are balanced. For example, the load beam  235  is 9 mm long, and the gimbal  238  is 2.5 mm long. Further, the length and width of the main body  235  of the load beam  237  are 5.7 mm and 2 mm, respectively. With the above structure, it is possible to stably fly the magnetic head slider  35 C. 
     A description will now be given, with reference to  FIG. 21 , of pitching and rolling of the magnetic head slider  35 C. 
     (1) Pitching 
     The magnetic head slider  35 C is rotated in the pitching direction indicated by arrow  44  in such a manner that the first, second and third beams  241 ,  242  and  244  and the load beam main body  237  are bent. At this time, all the beams  241 ,  242  and  244  are bent so as to be deformed in the form of arch shapes. The gimbal  238  is bent and hence the load beam main body  237  is bent. Hence, the pitch stiffness can be greatly reduced. 
     (2) Rolling 
     The magnetic head slider  35 C is rotated in the rolling direction indicated by arrow  45  in such a manner that the first and second beams  241  and  242  are respectively bent in the opposite directions and the load beam main body  237  is twisted. At this time, the gimbal  238  is bent and hence the load beam main body  237  is bent. Hence, the rolling stiffness can be greatly reduced. 
     A description will now be given of the first-order bend and the first-order twist of the magnetic head supporting mechanism  230  obtained when the load beam is vibrated. 
     (1) First-order Bend 
     The load beam  235  is bent and deformed, as shown in  FIG. 26 . More specifically, the load beam main body  237 , and the first, second and third beams  241 ,  242  and  244  of the gimbal  238  are bent as shown in  FIG. 24 . The overall load beam  235  is formed flexibly, but the resonance frequency of the first-order bend is high, while the stiffness is small. 
     (2) First-order Twist 
     The load beam  235  is twisted as shown in  FIG. 27 . The gimbal  238  is deformed and hence the load beam main body  237  is deformed. Hence, the overall load beam  235  is flexibly formed, but the resonance frequency of the first-order twist is high while the stiffness thereof is low. 
     Tables 3 and 4 show characteristics of the magnetic head support mechanism  230  according to the seventh embodiment of the present invention and the magnetic head supporting mechanism  30  of the first embodiment thereof shown in  FIG. 2 . 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 COMPARISON OF STIFFNESS 
               
               
                 (static characteristics by computer simulation) 
               
            
           
           
               
               
               
               
            
               
                   
                 Stiffness 
                 7th embodiment 
                 1st embodiment 
               
               
                   
                   
               
               
                   
                 pitch stiffness 
                 0.44 grf cm/rad 
                  1.5 grf cm/rad 
               
               
                   
                 roll stiffness 
                 0.24 grf cm/rad 
                  1.5 grf cm/rad 
               
               
                   
                 up/down stiffness 
                 0.36 grf/mm 
                 0.55 grf/mm 
               
               
                   
                 equivalent weight ratio 
                 0.76 
                 0.74 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 COMPARISON OF RESONANCE FREQUENCY 
               
               
                 (dynamic characteristic by computer simulation) 
               
            
           
           
               
               
               
               
            
               
                   
                 Stiffness 
                 7th embodiment 
                 1st embodiment 
               
               
                   
                   
               
               
                   
                 1st bend 
                 1.6 kHz 
                 2.1 kHz 
               
               
                   
                 1st twist 
                 4.4 kHz 
                 2.3 kHz 
               
               
                   
                 in-plane 
                 7.1 kHz 
                 8.5 kHz 
               
               
                   
                   
               
            
           
         
       
     
     More particularly, Table 3 the pitch stiffness, the roll stiffness, and the up/down stiffness of the load beam  235  obtained by means of a computer simulation. It can be from Table 3 that the pitch stiffness and the roll stiffness of the seventh embodiment of the present invention are approximately one-quarter of those of the first embodiment thereof. 
     Table 4 shows the resonance frequencies of the first and seventh embodiments of the present invention obtained by a computer simulation. It can be seen from Table 4 that the first-order bend resonance frequency, the first-order twist resonance frequency and the lateral resonance frequency are kept very high. 
     It can be seen from Tables 3 and 4 that the magnetic head supporting mechanism  230  according to the seventh embodiment of the present invention has a resonance frequency as high as that of the magnetic head supporting mechanism  30  according to the first embodiment, and stiffness much less than that of the mechanism  30 . Hence, the compact magnetic head slider  35 C can be stably flied. 
     In an alternative of the load beam, the base portion of the load beam  237  is bent, so that the load beam is supported in the same manner as shown in  FIG. 2  and the load F 1  shown in  FIG. 24  is obtained. In this case, only portions  255  and  256  outside of the slits  248  and  249  are bent. Hence, unnecessary strain is not exerted on the wiring patterns  91 – 94  located between the slits  248  and  249 . 
     A first variation of the gimbal  238  of the load beam  235  will be described. A gimbal  238   −1  shown in  FIG. 28  has a first beam  244   −1  having a long width A, and an opening  239   −1  having a long length B. First and second beams  241   −1  and  242   −1  are long. 
       FIG. 29  shows a second variation  238   −2  of the gimbal  238 . The gimbal  238   −2  has first and second beams  241   −2  and  242   −2  each having a small width C. 
       FIG. 30  shows a third variation  238   −3  of the gimbal  238 . The gimbal  238   −3  has first and second variations  241   −3  and  242   −3  having a large width D. 
       FIG. 31  shows a fourth variation  238   −4  of the gimbal  238 . The gimbal  238   −4  has a fourth beam  260  connecting the center of the end of the magnetic head slider fixing portion  240  and the load beam main body  237  together. The fourth beam  260  functions to prevent a deformation of the magnetic head slider fixing portion  240 , but increases the rotation stiffness. Hence, it is desired that the width of the fourth beam  260  be as small as possible and the length thereof are as long as possible. 
       FIG. 32  shows a fifth variation  238   −5  of the gimbal  238 . The gimbal  238   −5  has first and second arch-shaped beams  241   −5  and  242   −5 . 
     As shown in  FIG. 33 , a bent connecting plate  261  is fixed to an arm  236 A, and the load beam  235  is fixed to the connecting plate  261 . Hence, it is not necessary to subject the arm  236 A to bending stresses. 
     In the variations shown in  FIG. 28 through 32 , it can be said that the third beam  244  shown in  FIG. 21  has the same width as the fixing portion  240  and is integrated with the fixing portion  240 . 
     In the first through sixth embodiments, the load applied to the magnetic head slider is generated by bending the spring portion of the load beam. Alternatively, it is possible to employ the arm fixing structure used in the seventh embodiment of the present invention in which the spring portion is kept flat. 
     The present invention is not limited to the specifically disclosed embodiments and variations, and other variations and modifications may be made without departing from the scope of the present invention.