Abstract:
A head suspension for a disk drive includes a base ( 5 ) to be attached to a carriage, a load beam ( 3 ) having a rigid part ( 9 ) and a resilient part ( 11 ) supported by the base, to apply load on a data read/write head ( 19 ) arranged at a front end of the rigid part, a flexure ( 7 ) attached to the load beam and being provided with the head, and a guide face ( 27 ) formed on an edge ( 9   a ) of the rigid part where a jig is inserted, to guide the jig without wearing away the jig. The guide face is formed by providing the edge of the rigid part with an integral thin part that is thinner than the rigid part and bending the thin part, or by partly removing the edge of the rigid part. The jig is inserted into a head suspension module, which is made by arranging the head suspension and other identical head suspensions at regular intervals, such that the teeth of the jig slide on the guide faces of the head suspensions to maintain spaces between the rigid parts of the head suspensions, to install the head suspension module into the disk drive such that the heads of the head suspensions face disks in the disk drive.

Description:
REFERENCE TO RELATED APPLICATION 
   This is a divisional application of Ser. No. 10/132,822, filed Apr. 24, 2002 now U.S. Pat. No. 7,088,554, which is currently allowed. The subject matter of the aforementioned prior application is hereby incorporated herein by reference. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a head suspension for a disk drive installed in an information processing apparatus such as a personal computer. 
   2. Description of the Related Art 
   A hard disk drive (HDD) records and reproduces information to and from rotating magnetic or magneto-optical disks. The disks are supported with a carriage that is turned around a spindle by a positioning motor. 
   An example of the carriage is disclosed in U.S. Pat. No. 4,167,765. The carriage of this disclosure includes a carriage arm, a head suspension attached to a front end of the carriage arm, a head attached to the head suspension, and a slider attached to the head. The slider faces a disk. When the disk is rotated at high speed, the slider slightly floats from the disk, and an air bearing is formed between the disk and the slider. 
     FIG. 1  is a sectional view partly showing a hard disk drive having head suspensions according to a related art. The disk drive  101  has a carriage  105  that is turned around a spindle  103  by a positioning motor  107  such as a voice coil motor. The carriage  105  has a plurality of (four in  FIG. 1 ) carriage arms  109 , a head suspension  111  attached to a front end of each carriage arm  109 , and a head  113  attached to a front end of each head suspension  111 . 
   The carriage  105  is turned around the spindle  103 , to move the heads  113  onto a target track on disks  115 . Each head  113  includes a slider  117  to be positioned onto a target track on the disk  115  and a transducer (not shown) supported with the slider  117 . 
   When the disks  115  are rotated at high speed, air enters between the disks  115  and the sliders  117  to slightly float the sliders  117  from the disks  115  and form air bearings between them. 
     FIGS. 2 ,  3 A, and  3 B show the head suspension  111 . The head suspension  111  includes a load beam  119  made of a precision thin plate spring, a flexure  121  made of a very thin plate spring fixed to the load beam  119  by, for example, laser welding, and a base plate  123  fixed to a base of the load beam  119  by, for example, laser welding. The base plate  123  is attached to a suspension attaching face of the carriage arm  109 . 
   Recent hard disk drives employ high-density disks and drive the disks at high speed. Such high-density disks involve narrow tracks, and therefore, vibration such as butterfly mode vibration of the head suspension  111  caused by air disturbance results in moving the head  113  away from a track center. 
   It is important, therefore, to control the amplitudes and frequencies of various resonance modes and air disturbance concerning the head suspensions  111  and carriage arms  109  between the actuator  107  and the sliders  117  in the disk drive  101 . The recent high-density, high-speed disks require head suspensions of high rigidity and low spring constant. 
   To achieve the requirements, the load beam  119  of  FIGS. 3A and 3B  has a channel  125 . The load beam  119  has a rigid part  119   a  that extends for a length L 1  and needs high rigidity and a resilient part  119   b  that extends for a length L 2  and needs a low spring constant. To simultaneously satisfy these needs, the resilient part  119   b  is thinned and edges of the rigid part  119   a  are shaped into the channel  125  to compensate the thinness of the rigid part  119   a  that is restricted by the thinness of the resilient part  119   b.    
   The channel  125  provides another function when the head suspension  111  is installed into the disk drive  101 . 
     FIG. 4  shows a comb  127  used when installing a head suspension module into a disk drive. The head suspension module consists of a plurality of head suspensions arranged at regular intervals. In  FIG. 4 , the comb  127  has two teeth  129  and  131  corresponding to the number of head suspensions included in the module.  FIG. 5  shows an example of the head suspension module. This module consists of four head suspensions  111 . 
   The teeth  129  and  131  of the comb  127  are inserted into the head suspension module as shown in  FIG. 5  to maintain a given space between the adjacent sliders  117  ( FIG. 1 ). The comb  127  enables horizontally to insert the head suspensions between the disks  115  ( FIG. 1 ) so that the sliders  117  may face the disks  115 . After the head suspension module is fixed at a proper position in the disk drive  101 , the comb  127  is removed from the head suspension module. In this way, the comb  127  is used to smoothly insert a module of head suspensions between disks in a disk drive. 
   When inserting the teeth  129  and  131  of the comb  127  between the head suspensions  111 , curves  125   a  ( FIG. 3B ) of the channel  125  serve as guides to reduce friction between the load beams  119  and the teeth  129  and  131 . 
   The channel  125 , however, causes air disturbance when the disks  115  are rotated at high speed, to flutter the load beams  119 . 
   To solve the problem, this applicant has proposed a head suspension for a disk drive in Japanese Patent Application No. 11-263705. This head suspension simultaneously realizes high rigidity for a rigid part ( 119   a ) and a low spring constant for a resilient part ( 119   b ) by separating the resilient part from the rigid part and by making the rigid part thicker than the resilient part. The rigid part has no bends, and therefore, causes no air disturbance and load beam fluttering when disks are rotated at high speed. 
   Instead of having no bends, the rigid part of the disclosure has sharp edges  133  as shown in  FIG. 6 . When the tooth  129  of the comb  127  is inserted between the head suspensions, the edge  133  of the rigid part  119   a  scrapes the teeth  129 , and the scraped dust spreads over the disks  115  to hinder the operation of the disk drive. In addition, the sharp edges  133  quickly wear the teeth of the comb  127 , thereby deteriorating the durability of the comb  127 . 
   SUMMARY OF THE INVENTION 
   The present invention provides a head suspension for a disk drive, capable of minimizing the wear of a comb even if the head suspension has no rigidity-improving bends. 
   A first aspect of the present invention provides a head suspension for a disk drive, having a base to be attached to a carriage, a load beam having a rigid part and a resilient part supported by the base, to apply load on a data read/write head arranged at a front end of the rigid part, a flexure attached to the load beam and being provided with the head, and a guide face formed on an edge of the rigid part where a jig is inserted, to guide the jig without wearing away the jig. The guide face is formed by providing the edge of the rigid part with an integral thin part that is thinner than the rigid part and bending the thin part, or by partly removing the edge of the rigid part. The jig is inserted into a head suspension module, which is made by arranging the head suspension and other identical head suspensions at regular intervals, such that teeth of the jig slide on the guide faces of the head suspensions to maintain spaces between the rigid parts of the head suspensions, to install the head suspension module into the disk drive such that the heads of the head suspensions face disks in the disk drive. 
   In the head suspension of the first aspect, a second aspect of the present invention forms the thin part by etching the edge of the rigid part. 
   In the head suspension of any one of the first and second aspects, a third aspect of the present invention makes an outer face of a bend formed by bending the thin part protrude from a face of the rigid part on which the flexure is arranged. 
   In the head suspension of the first aspect, a fourth aspect of the present invention partly removes the edge of the rigid part by pressing. 
   In the head suspension of the first aspect, a fifth aspect of the present invention provides the rigid part with at least three layers including metal plates and a resin layer sandwiched between the metal plates and forms the thin part from one of the metal plates. 
   In the head suspension of any one of the first, second, and fifth aspects, a sixth aspect of the present invention makes the height after bent of the thin part smaller than the thickness of the rigid part. 
   According to the first aspect, a plurality of head suspensions are arranged at regular intervals to form a head suspension module. The module is installed into a disk drive by inserting a jig between the rigid parts of the head suspensions such that teeth of the jig slide on the guide faces of the head suspensions to maintain spaces between the rigid parts. The jig enables easily to install the module into the disk drive such that the heads at the front ends of the head suspensions face disks in the disk drive. 
   The first aspect forms the guide face on the edge of the rigid part where the jig is inserted. When the jig is inserted between the rigid parts of the head suspension module, the jig is guided along the guide faces, to minimize the wearing of the jig, prevent the jig from producing abrasion dust, and keep the disks clean. 
   Minimizing the wearing of the jig results in improving the durability of the jig. The guide face is formed by providing the edge of the rigid part with an integral thin part that is thinner than the rigid part and bending the thin part, or by partly removing the edge of the rigid part. The guide face is easy to form. 
   In addition to the effects of the first aspect, the second aspect easily and precisely forms the thin part of the rigid part by etching the edge of the rigid part. The thin part is easy to bend to form the guide face. This results in extending the service life of an apparatus used to form the guide face. 
   In addition to the effects of the first and second aspects, the third aspect makes an outer face of a bend formed by bending the thin part protrude from a face of the rigid part on which the flexure is arranged. When the jig is inserted, the jig moves along the outer face of the bend, to keep a space between the jig and the surface of the rigid part, thereby protecting conductors formed on the flexure. 
   In addition to the effects of the first aspect, the fourth aspect partly removes the edge of the rigid part by pressing, thereby easily and correctly forming the guide face. The fourth aspect forms no protrusion on the edges of the rigid part, to cause no air disturbance when the disks are rotated at high speed in the disk drive. Namely, the fourth aspect surely prevents vibration of the head suspension. 
   In addition to the effects of the first aspect, the fifth aspect provides the rigid part of the head suspension with at least three layers including metal plates and a resin layer sandwiched between the metal plates. The thin part of the rigid part is made from one of the metal plates, to easily form the guide face. The three-layered structure of the rigid part is effective to reduce the weight of the head suspension and improve the rigidity thereof. 
   In addition to the effects of the first, second, and fifth aspects, the sixth aspect makes the height after bent of the thin part of the rigid part smaller than the thickness of the rigid part. As a result, the thin part after bent causes no air disturbance when the disks are rotated at high speed in the disk drive, thereby preventing vibration of the head suspension. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a sectional view partly showing head suspensions installed in a hard disk drive according to a related art; 
       FIG. 2  is a plan view showing one of the head suspensions of  FIG. 1  seen from a flexure side; 
       FIG. 3A  is a perspective view showing a load beam of the head suspension of  FIG. 2 ; 
       FIG. 3B  is a sectional view taken along a line SA-SA of  FIG. 3A ; 
       FIG. 4  is a perspective view partly showing a comb serving as a jig to install a head suspension module into a disk drive; 
       FIG. 5  is a perspective view showing the comb of  FIG. 4  inserted into a head suspension module; 
       FIG. 6  is a sectional view showing a tooth of the comb of  FIG. 4  in contact with a rigid part of a head suspension; 
       FIG. 7  is a plan view showing a head suspension seen from a flexure side according to a first embodiment of the present invention; 
       FIG. 8  is an enlarged perspective view showing a guide face of the head suspension of  FIG. 7  seen from the flexure side; 
       FIG. 9  is an enlarged perspective view showing the guide face seen from the opposite side of  FIG. 8 ; 
       FIG. 10  is an enlarged sectional view showing the guide face of  FIG. 7 ; 
       FIG. 11A  shows a thin part formed on the rigid part of the head suspension according to the first embodiment; 
       FIG. 11B  shows a guide face formed from the thin part of  FIG. 11A ; 
       FIG. 12  is a sectional view showing a rigid part of a head suspension for a disk drive according to a second embodiment of the present invention; 
       FIG. 13A  is a sectional view showing an edge of the rigid part of the second embodiment; 
       FIG. 13B  is a sectional view showing a guide face formed on the edge of  FIG. 13A ; 
       FIG. 14A  is a sectional view showing a thin part formed on a rigid part of a head suspension for a disk drive according to a third embodiment of the present invention; 
       FIG. 14B  is a sectional view showing a guide face formed from the thin part of  FIG. 14A ; 
       FIG. 15  is a perspective view showing a head suspension for a disk drive according to a fourth embodiment of the present invention; 
       FIG. 16  is a perspective view showing a head suspension for a disk drive according to a fifth embodiment of the present invention; 
       FIG. 17  is a perspective view showing a load beam of a head suspension for a disk drive according to a sixth embodiment of the present invention; 
       FIG. 18  is a sectional view taken along a line SB-SB of  FIG. 17 ; 
       FIG. 19  is a perspective view showing a load beam of a head suspension for a disk drive according to a modification of the sixth embodiment; and 
       FIG. 20  is a perspective view showing a load beam of a head suspension for a disk drive according to a seventh embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF EMBODIMENTS 
   First Embodiment 
     FIG. 7  is a plan view showing a head suspension  1  for a disk drive according to the first embodiment of the present invention. The head suspension  1  includes a load beam  3 , a base  5 , and a flexure  7 . 
   The load beam  3  has a rigid part  9  and a resilient part  11 . The rigid part  9  is made of, for example, stainless steel and is relatively thick, for example, 0.1 mm thick. 
   The resilient part  11  is independent of the rigid part  9  and is made of, for example, a thin stainless steel rolled plate. The resilient part  11  has a precision low spring constant that is lower than that of the rigid part  9 . The thickness of the resilient part  11  is, for example, t=0.040 mm. An end of the resilient part  11  is fixed to a rear end  9   c  of the rigid part  9  by, for example, laser welding. The other end of the resilient part  11  forms an integral reinforcing plate  13 . 
   The base  5  has a base plate  15 , which is laid over the reinforcing plate  13  and fixed thereto by, for example, laser welding. Namely, the base plate  15  is reinforced with the reinforcing plate  13 , to form the base  5 . 
   The flexure  7  includes a metal base made of, for example, a resilient thin stainless rolled plate. An insulating layer is formed on the metal base, and conductors  17  are formed on the insulating layer. The flexure  7  is fixed to the rigid part  9  by, for example, laser welding. One ends of the conductors  17  are electrically connected to terminals  21  of a head  19 , and the other ends thereof are electrically connected to terminals  23  of the base  5 . The head  19  has a slider  25 . 
   The rigid part  9  has longitudinal edges  9   a . Each of the edges  9   a  is provided with a guide face  27  at a position where a tooth of a comb (such as the tooth  129  of the comb  127  of  FIG. 4 ) is inserted. According to the first embodiment, the guide face  27  is formed in a range S along the edge  9   a  in front of the resilient part  11 . The guide face  27  of the first embodiment is formed on each edge  9   a  to maintain the horizontal balance of the rigid part  9 . The guide face  27  may be formed on one edge  9   a  where the comb is inserted. 
     FIGS. 8 and 9  are enlarged perspective views showing the guide face  27 , in which  FIG. 8  is a view seen from the flexure  7  side and  FIG. 9  is a view seen from the opposite side. The guide face  27  is formed on the edge  9   a  of the rigid part  9 . 
     FIG. 10  is a sectional view showing the guide face  27 . According to the first embodiment, each edge  9   a  of the rigid part  9  is provided with a thin part  29  thinner than the rigid part  9 , and the thin part  29  is bent to form the guide face  27 . The guide face  27  has a slant  27   a  and a curve  27   b . The curve  27   b  smoothly connects the slant  27   a  to a surface  9   b  of the rigid part  9 . 
   An inclination angle of the slant  27   a  relative to the surface  9   b  is, for example, θ=40°. An extension of the slant  27   a  and an extension of the surface  9   b  form an intersection  31 . The intersection  31  is distanced from a front end  33  of the thin part  29  by, for example, H=0.05 mm. The inclination θ and distance H are optional. The height of the bend from the surface  9   b  is lower than the height of the rigid part  9 . The height of the bend from the surface  9   b  may be greater than the height of the rigid part  9 . 
     FIGS. 11A and 11B  show a method of forming the guide face  27 . In  FIG. 11A , the edge  9   a  of the rigid part  9  is etched to form a recess  35  and the thin part  29  thinner than the rigid part  9 . In  FIG. 11B , a press is used to smoothly bend the thin part  29  to form the guide face  27  along the edge  9   a . In this way, the guide face  27  is easily and correctly formed by etching and pressing. The pressing needs only small force, to maintain proper operation of the press for a long time. 
   A plurality of head suspensions  1  each having the guide faces  27  are assembled into a head suspension module, and the module is installed into a disk drive by inserting the comb  127  into the rigid parts  9  as shown in  FIG. 5 . At this time, the teeth of the comb  127  contact with the slants  27   a , enter between the rigid parts  9 , gradually widen spaces between the rigid parts  9 , slide on the slants  27   a  and curves  27   b , and move over the surfaces  9   b  of the rigid parts  9 . As a result, the teeth of the comb  127  are not rubbed by the edges of the rigid parts  9 , to thereby are not or slightly worn by the edges of the rigid parts  9 . 
   The head suspension module is installed as shown in  FIG. 1  so that the sliders  25  of the heads  19  face the disks  115 . In this case, the comb  127  produces substantially no abrasion dust due to the guide faces  27 , to keep the disks  115  clean and improve the durability of the comb  127 . 
   According to the first embodiment, the rigid part  9  is thick and highly rigid, and the edges  9   a  of the rigid part  9  are provided with the thin parts  29  to easily form the guide faces  27 . 
   According to the first embodiment, the rigid part  9  maintains high rigidity, and at the same time, the separate resilient part  11  realizes a low spring constant. In the load beam  3 , the material and thickness of the rigid part  9  are not restricted by those of the resilient part  11 . Namely, the rigid part  9  and resilient part  11  may have individual materials and thicknesses, to satisfy requirements for the head suspension  1 . 
   The rigid part  9  realizes high rigidity without a channel shape, and the height after bent of the thin part  29  is lower than the height of the rigid part  9 . As a result, the rigid part  9  shows low air resistance. This minimizes air disturbance when the disks  115  are rotated at high speed and prevents the fluttering of the head suspension  1 . 
   Second Embodiment 
     FIGS. 12 ,  13 A, and  13 B show a rigid part  9  of a head suspension for a disk drive according to the second embodiment of the present invention. The second embodiment partly removes each edge  9   a  of the rigid part  9  and forms a guide face  27 A. The guide face  27 A has an inclination angle of, for example, θ 1 =40° relative to a surface  9   b  of the rigid part  9 . The width of the guide face  27 A is, for example, H 1 =0.05 mm. The inclination angle θ 1  and width H 1  are optional. 
     FIGS. 13A and 13B  show a method of forming the guide face  27 A. In  FIG. 13A , a press is used to remove an edge corner  37  of the rigid part  9 , thereby forming the guide face  27 A as shown in  FIG. 13B . 
   The guide face  27 A of the second embodiment provides the same effects as the guide face  27  of the first embodiment. The second embodiment forms the guide face  27 A by removing the edge corner  37  without bending. Accordingly, the guide face  27 A is easier to form than the guide face  27  of the first embodiment. The guide face  27 A has no bend, and therefore, is free from air disturbance and surely prevents vibration of the head suspension. The guide face  27 A formed by pressing is advantageous in maintaining the weight balance of the head suspension even if the guide face  27 A is formed on one edge of the rigid part  9 . 
   Removing the edge corner  37  may be carried out by etching. The guide face  27 A may have a curve smoothly connected to the surface  9   b  of the rigid part  9 . 
   Third Embodiment 
     FIGS. 14A and 14B  show a rigid part  9  of a head suspension for a disk drive according to the third embodiment of the present invention. In  FIG. 14A , each edge  9   a  of the rigid part  9  is etched to form a recess  35 B and a thin part  29 B thinner than the rigid part  9 . 
   In  FIG. 14B , a press is used to bend the thin part  29 B, to form a guide face  27 B having a slant  27 Ba and a curve  27 Bb. The height after bent of the thin part  29 B is set like that of the thin part  29  of the first embodiment. The curve  27 Bb is an outer face of a bend  29 Ba of the thin part  29 B and protrudes from the surface  9   b  of the rigid part  9 . According to the third embodiment, the height of the protrusion of the curve  27 Bb from the surface  9   b  is equal to or greater than the height of a flexure  7  arranged on the surface  9   b . The height of the protrusion of the curve  27 Bb from the surface  9   b , however, is optional. 
   The third embodiment provides substantially the same effects as the first embodiment. According to the third embodiment, the curve  27 Bb protrudes from the surface  9   b . A tooth of a comb (for example, the tooth  129  of the comb  127  of  FIG. 4 ) moves on the curve  27 Bb and keeps a space from the surface  9   b , thereby protecting conductors formed on the flexure  7 . If the height of the protrusion of the curve  27 Bb from the surface  9   b  is equal to or greater than the height of the flexure  7 , the conductors on the flexure  7  are surely protected. 
   Fourth Embodiment 
     FIG. 15  is a perspective view showing a head suspension  1 C for a disk drive according to the fourth embodiment of the present invention. In  FIG. 15 , parts corresponding to those of the first embodiment are represented with like reference numerals. 
   The head suspension  1 C has a load beam  3 C and a base  5 C. The load beam  3 C includes a rigid part  9 C and a resilient part  11 C having a rectangular frame shape. The base  5 C consists of only a base plate  15 C. An end  11 Ca of the resilient part  11 C is laid on an end  9 Ca of the rigid part  9 C and is fixed thereto by, for example, laser welding. Another end  11 Cb of the resilient part  11 C is laid on a front end of the base plate  15 C and is fixed thereto by, for example, laser welding. The resilient part  11 C has an opening  11 Cc and sides  11 Cd and  11 Ce to provide a low spring constant. 
   The rigid part  9 C has guide faces  27  where a tooth of a comb (such as the tooth  129  of the comb  127  of  FIG. 4 ) is inserted. The fourth embodiment forms the guide face  27  on each edge of the rigid part  9 C to maintain the horizontal weight balance of the head suspension  1 C. The guide face  27  may be formed only on one edge of the rigid part  9 C where a tooth of the comb is inserted. The guide face  27  may be any one of the guide faces of the second to third embodiments. 
   The fourth embodiment provides the same effects as the first to third embodiments. 
   Fifth Embodiment 
     FIG. 16  is a perspective view showing a head suspension  1 D for a disk drive according to the fifth embodiment of the present invention. In  FIG. 16 , parts corresponding to those of  FIG. 15  are represented with like reference numerals. 
   The head suspension  1 D has a base plate  15 D that is longer than the base plate  15 C of  FIG. 15 . The base plate  15 D also serves as a carriage arm ( 109  of  FIG. 1 ). 
   A guide face  27  is formed on each edge of a rigid part  9 C of the head suspension  1 D, to provide the same effects as the fourth embodiment. The guide face  27  may be any one of the guide faces of the first to third embodiments. 
   Sixth Embodiment 
     FIG. 17  is a perspective view showing a load beam  3 E of a head suspension for a disk drive according to the sixth embodiment of the present invention, and  FIG. 18  is a sectional view taken along a line SB-SB of  FIG. 17 . 
   In  FIG. 17 , only the load beam  3 E proper is shown and other parts including a flexure are omitted. The load beam  3 E has a rigid part  9 E and a resilient part  11 E. The rigid part  9 E has substantially a triangle shape with a base end  9 Eb gradually narrowing toward a front end  9 Ea. The thickness of the rigid part  9 E is, for example, t=100 μm. 
   Referring to  FIGS. 17 and 18 , the rigid part  9 E has a three-layer structure with metal plates  37   a  and  37   b  sandwiching a resin layer  37   c  and bonded each other. The metal plates  37   a  and  37   b  are made of, for example, stainless steel (SUS). The thickness of the metal plate  37   a  is, for example, t=38 μm, and the thickness of the metal plate  37   b  is, for example, t=20 μm. 
   The resin layer  37   c  is a resin plate made of, for example, polyimide (PI) resin or epoxy resin. The thickness of the resin layer  37   c  is, for example, t=42 μm. The total thickness of the metal plates  37   a  and  37   b  and resin layer  37   c  is set to be 100 μm. These thicknesses are only examples. Depending on rigidity set for the rigid part  9 E, the individual thicknesses of the metal plates  37   a  and  37   b  and resin layer  37   c  and the total thickness thereof are properly set. 
   The rigid part  9 E has bends  39 , which are integral with the metal plate  37   b . Each bend  39  is lower than the rigid part  9 E. The bends  39  are formed by preparing three layers ( 37   a ,  37   b ,  37   c ) having protrusions corresponding to the bends  39 , etching off the protrusions on the metal plate  37   a  and resin layer  37   c  to leave the protrusions on the metal plate  37   b , and bending the protrusions on the metal plate  37   b  by press. 
   The bends  39  provide guide faces  27 E. According to the sixth embodiment, the guide faces  27 E are formed on both edges of the rigid part  9 E to maintain the horizontal weight balance of the load beam  3 E. The guide face  27 E may be formed only on one edge of the rigid part  9 E where a tooth of a comb (such as the tooth  129  of the comb  127  of  FIG. 4 ) is inserted. 
   According to the sixth embodiment, the height of the bend  39  is equal to a surface  9 Eb of the rigid part  9 E. The height of the bend  39  may be lower than the surface  9 Eb, i.e., smaller than the thickness of the rigid part  9 E. The height of the bend  39  may be greater than the thickness of the rigid part  9 E. 
   The front end  9 Ea of the rigid part  9 E consists of only the metal plate  37   b  and has a dimple  41 . The front end  9 Ea is formed by, for example, etching off the metal plate  37   a  and resin layer  37   c.    
   The resilient part  11 E is integral with the metal plate  37   a  at an end of the rigid part  9 E. Namely, the resilient part  11 E has a single-layer structure. The resilient part  11 E is made of, for example, stainless steel. The thickness of the resilient part  11 E is, for example, t=38 μm. The resilient part  11 E has an opening  11 Ea and sides  11 Ec and  11 Ed to provide a low spring constant. 
   Opposite to the rigid part  9 E, the resilient part  11 E is integral with a reinforcing metal plate  43   a  for reinforcing a base. The metal plate  43   a  is made of, for example, stainless steel, and the thickness thereof is, for example, t=38 μm. The metal plate  43   a  and another reinforcing metal plate  43   b  sandwich a resin layer  43   c  and are bonded each other to form a three-layer reinforcing part  45 . 
   The metal plates  43   a  and  43   b  and resin layer  43   c  of the reinforcing part  45  resemble the metal plates  37   a  and  37   b  and resin layer  37   c  of the rigid part  9 E. The metal plate  43   b  is made of stainless steel, and the thickness thereof is, for example, t=20 μm. The resin layer  43   c  is made of polyimide resin or epoxy resin, and the thickness thereof is, for example, t=42 μm. 
   The reinforcing part  45  is attached to a base plate and fixed thereto by, for example, laser welding. The base plate is attached to a carriage arm. 
   The guide faces  27 E of the sixth embodiment provide the same effects as the first to fifth embodiments. The height of each bend  39  is substantially equal to the height of the surface  9 Eb of the rigid part  9 E, and therefore, causes no air disturbance and prevents vibration of the load beam  3 E. 
   According to the sixth embodiment, the bends  39  are formed only on the metal plate  37   b , and therefore, are easy to form with the dimple  41 . 
   The rigid part  9 E has the three-layer structure interposing the resin layer  37   c , to remarkably improve the rigidity of the rigid part  9 E. The interposed resin layer  37   c  provides a damper effect. The resilient part  11 E is made of a single plate to easily provide a low spring constant. As a result, the head suspension of the sixth embodiment realizes a high resonance frequency and the damper effect, to surely prevent the fluttering of the head suspension. 
   The three-layer reinforcing part  45  interposing the resin layer  43   c  provides high rigidity to surely attach the base to a carriage arm. The load beam  3 E as a whole is a three-layer structure with the interposed resin layers  37   c  and  43   c , to greatly reduce the weight of the head suspension. 
   Each bend  39  may be inclined so that the guide face  27 E may have a slant and a curve. The resilient part  11 E may be integral with the metal plate  37   b  as shown in  FIG. 19 . In this case, the thickness of the metal plate  37   b  is equalized with the thickness of the resilient part  11 E. 
   According to the sixth embodiment, the resilient part  11 E may have a two-layer structure consisting of a metal plate and a resin layer, or a three-layer structure consisting of two metal plates sandwiching a resin layer. In this case, the rigid part  9 E or the rigid part  9 E and reinforcing part  45  may have a multilayer structure made of metal and resin layers whose number is greater than the number of layers of the resilient part  11 E. 
   Seventh Embodiment 
     FIG. 20  is a perspective view showing a load beam  3 F of a head suspension for a disk drive according to the seventh embodiment of the present invention. In  FIG. 20 , parts corresponding to those of the sixth embodiment are represented with like reference numerals. 
   In the load beam  3 F, a rigid part  9 E and a reinforcing part  45  have each a three-layer structure like the sixth embodiment. In addition, a resilient part  11 F also has a three-layer structure consisting of metal plates  47   a  and  47   b  sandwiching a resin layer  47   c . The metal plate  47   a  is integral with a metal plate  37   a  and reinforcing metal plate  43   a , and these metal plates have the same thickness. The metal plate  47   b  is integral with a metal plate  37   b  and a reinforcing metal plate  43   b , and these metal plates have the same thickness. The resin layer  47   c  is integral with resin layers  37   c  and  43   c , and these resin layers have the same thickness. 
   The seventh embodiment provides the same effects as the sixth embodiment.