Patent Publication Number: US-2009238952-A1

Title: Method of manufacturing slider

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a method of manufacturing a head slider, more precisely relates to a method of manufacturing a head slider, in which a row bar cut from a wafer substrate is uniquely processed. 
     In a head slider of a magnetic storage unit, step-shaped sections, i.e., an air bearing surface (ABS) section(s) and a step section(s), are formed in a facing surface, which faces a surface of a recording medium, thereby the head slider can be floated from the surface of the recording medium by an air stream, which is generated by rotation of the recording medium. Step-shaped sections of head sliders have different configurations. In some head sliders, step-shaped sections have different heights. 
     An example of a head slider having step-shaped sections, whose heights are different, is shown in  FIG. 23 . The head slider  10  is formed on a substrate  11  composed of ALTIC (Al 2 O 3 —TiC), and ABS sections  14   a  and  14   b  and step sections  15   a  and  15   b  are formed in a facing surface of the substrate  11 , which will face a recording medium. The step sections  15   a  and  15   b  are one-step lower than the ABS sections  14   a  and  14   b . Further, a groove surface  16  , which is outwardly extended from the ABS sections  14   a  and  14   b  and the step sections  15   a  and  15   b , is one-step lower than the step sections  15   a  and  15   b . Note that, in the present specification, surfaces of the ABS sections  14   a  and  14   b , which will face the recording medium, are called air bearing surfaces (ABSs); surfaces of the step sections  15   a  and  15   b , which will face the recording medium, are called step surfaces. 
     A sensor  12 , which includes a read-element and a write-element, is formed on a side face of the substrate  11 , which is perpendicular to the facing surface of the head slider  10 . The sensor  12  is constituted by thin films so as to form the read-element, etc. on a wafer substrate. 
     The ABS sections  14   a  and  14   b , the step sections  15   a  and  15   b , and the groove surface  16  are formed by the steps of: laminating films on the wafer substrate; cutting a row bar from the wafer substrate; abrading a surface of the row bar, which will face the recording medium; and ion-milling the abraded surface of the row bar so as to form the step-shaped sections. 
     The conventional method is disclosed in, for example, Japanese Laid-open Patent Publications No. 2005-276284 and No. 2002-373477. 
     However, the conventional method of manufacturing a head slider has following problems. Namely, when the step-shaped sections are formed in the facing surface of the head slider, the head slider is ion-milled, so burrs will stick onto the facing surface and will damage the recording medium. 
     The production process of the head slider includes steps of abrading and cutting the ALTIC substrate, so particles of the ALTIC material, which fall from a tip or a crack formed while processing the wafer substrate, invade into a clearance between the head slider and the recording medium. Therefore, disk crush will be caused during the operation. 
     Heights of the ABS sections and the step sections are fixed, but a relative rotational speed of the recording medium with respect to the head slider is varied depending on positions of the head slider with respect to the recording medium, e.g., a position facing a center part of the recording medium, a position facing an outer part of the recording medium. Therefore, an amount of floating the head slider from the recording medium varies. 
     To restrain the variation of the amount of floating the head slider, a dynamic flighing height (DFH) method, in which a heater circuit is formed in the sensor and a clearance between the sensor and the recording medium is adjusted by thermal expansion of a thermal expansion material of the sensor which is controlled by passing an electric current through the heater circuit, is proposed. However, the heater circuit is located close to the sensor, so the heat will badly influence characteristics of the sensor. 
     The heater circuit may be formed in the ABS of the head slider, but the head slider or the sensor is located close to the recording medium and the disk crush will be occurred. 
     SUMMARY OF THE INVENTION 
     The present invention was conceived to solve the above described problems. 
     An object of the present invention is to provide a method of manufacturing a head slider, which is capable of improving a floating characteristic and an electromagnetic conversion characteristic of the head slider and preventing a recording medium from being damaged by burrs, etc. stuck on a surface of the head slider. 
     To achieve the object, the present invention has following constitutions. 
     Namely, the method of manufacturing a head slider comprises the steps of: forming terminals on a leading end face of a row bar, to which an air inflows; forming a resist pattern, which corresponds to a configuration of an air bearing surface (ABS) section to be formed on a facing surface of the row bar, which will face a storage medium; partially thinning the facing surface of the row bar until reaching a groove surface, with using the resist pattern as a mask, so as to form the ABS section; forming a base layer of a step section on the groove surface; forming a heater circuit, which is electrically connected to the terminals, on the base layer; and coating the base layer, on which the heater circuit has been formed, with a thermal expansion material layer so as to form the step section. 
     In the method, the base layer of the step section may be formed on the groove surface after forming the ABS section, the heater circuit may be formed on the base layer, and the base layer, on which the heater circuit has been formed, may be coated with the thermal expansion material layer. With this method, the heater circuit can be formed in the ABS section. 
     The method may further comprise the step of finish-abrading an ABS of the ABS section, which is performed after forming the ABS section and the step section. With this method, the ABS can be accurately formed. 
     The method may further comprise the steps of: cutting the row bar, which is supported by a supporting jig, to form the head slider after forming the ABS section and the step section; and finish-abrading an ABS of the head slider, which is supported by the supporting jig. 
     The method may further comprise the steps of: cutting the row bar, which is supported by a supporting jig, to form the head slider after forming the ABS section and the step section; and coating an outer surface of the head slider, which is supported by the supporting jig, with a protection film. With this method, the head slider including the outer surface can be coated with the protection film. 
     By employing the method of the present invention, the heater circuit is formed in the step section, so that a height of the step surface can be adjusted by controlling thermal expansion of the step section. Height variation of the step surface, which is caused in the steps of processing the head slider, can be absorbed, so that characteristics of the head slider can be improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present invention will now be described by way of examples and with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view of an ALTIC substrate, on which head sliders will be formed; 
         FIG. 2  is a perspective view of the ALTIC substrate, on which element sections are formed; 
         FIG. 3  is a perspective view of stack bars, which are separated from the ALTIC substrate; 
         FIG. 4  is an explanation view showing a manner of processing a row bar; 
         FIG. 5  is a plan view of a setting plate, on which row bars are set; 
         FIG. 6  is a plan view of the processed row bars; 
         FIG. 7  is an explanation view showing a manner of cutting the row bar into head sliders; 
         FIG. 8  is a partial perspective view showing a structure of the row bar; 
         FIG. 9  is a partial perspective view of the row bar, in which terminals are formed; 
         FIG. 10  is a partial perspective view of the row bar, in which an LE surface is coated with an insulating material; 
         FIG. 11  is a partial perspective view of the row bar, in which resist patterns for forming ABS sections are formed in an abraded surface; 
         FIG. 12  is a partial perspective view of the row bar, in which the ABS sections and a groove surface are formed; 
         FIG. 13  is a partial perspective view of the row bar, in which base layers of step sections are formed; 
         FIG. 14  is a partial perspective view of the row bar, in which heater circuits are respectively formed in the base layers; 
         FIG. 15  is a partial perspective view of the row bar, in which the heater circuits are respectively coated with thermal expansion material layers; 
         FIG. 16  is a partial perspective view of the row bar, in which a concave part for forming a heater circuit is formed in the ABS section; 
         FIG. 17  is a partial perspective view of the row bar, in which the heater circuit is formed in the ABS section; 
         FIG. 18  is a perspective view showing a manner of cutting the row bar into head sliders 
         FIG. 19  is an explanation view showing a manner of finish-abrading the ABSs of the row bar; 
         FIG. 20  is a perspective view of the abraded head slider; 
         FIG. 21  is a perspective view of the head slider coated with a protection film; 
         FIG. 22  is a sectional view taken along a line A-A shown in  FIG. 21 , wherein an arrangement of the ABS, the step surfaces and the groove surface is shown; and 
         FIG. 23  is a perspective view of the conventional head slider having the ABS sections and the step sections. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. 
     (Basic Steps of Manufacturing Head Slider) 
     Basic steps of manufacturing a head slider will be explained with reference to  FIGS. 1-7 . A wafer substrate  20 , which is composed of ALTIC (Al 2 O 3 —TiC) and on which head sliders will be formed, is shown in  FIG. 1 . In  FIG. 2 , element sections  22 , which are formed by laminating films and each of which has a sensor including a read-element and a write-element, are formed on the ALTIC substrate  20 . A number of the element sections  22  are metrically formed on the ALTIC substrate  20 . 
     In  FIG. 3 , the ALTIC substrate  20 , on which the element sections  22  have been formed, is cut along arrays of the element sections  22  so as to form a plurality of blocks  24 . Each of the blocks  24  is called a stack bar, in each of which row bars are piled. In each of the row bars, a plurality of the element sections  22  are serially arranged in the longitudinal direction. 
     In  FIG. 4 , the stack bar  24  is cut to form row bars  27 . In the shown step, the stack bar  24  is adhered to a supporting jig  25 , which is composed of an electrically conductive ceramic, and then air bearing surfaces (ABSs) of the stack bar  24  in which the sensors are exposed, are abraded, by an abrasive plate  26 , until sizes of the sensors reach a prescribed size. 
     Generally, the ABSs and the sensors are finish-abraded, in the abrading step, to have the prescribed size. On the other hand, in the method of the present invention, the ABSs are finish-abraded and the sensors are finally positioned in the following step. Therefore, an abrasive margin, which will be removed in the finish-abrading step, is left in this abrading step. 
     After completing the abrading step, the outermost row bar  27  of the stack bar  24  is cut from the stack bar  24  and set on a setting plate  28  composed of an electrically conductive ceramic (see  FIG. 5 ). 
     A cut surface of the stack bar  24  is abraded every time the row bar  27  is cut from the stack bar  24 , and then the new outermost row bar  27  is cut from the stack bar  24 . This process is repeated, and the row bars  27  cut from the stack bar  24  are set on the setting plate  28  in order (see  FIG. 5 ). The row bars  27  are set on the setting plate  28  with their abraded surfaces being in an upward direction. 
     Next, ABS sections and step sections of the row bars  27  are formed in the sate in which the row bars  27  are set on the setting plate  28 . The ABS sections and the step sections formed in the abraded surfaces of the row bars  27  are shown in  FIG. 6 . 
     In  FIG. 7 , the row bar  27 , in which the ABS sections and the step sections have been formed, is adhered onto a ceramic tool  29 , and the row bar  27  is cut into separated head sliders  30 . With this step, the separated head sliders  30 , in each of which the ABS sections and the step sections are formed in the abraded surface, can be produced. 
     (Characteristic Steps of Manufacturing Head Slider) 
     The above described production steps shown in  FIGS. 1-7  are the basic steps of manufacturing the head slider. On the other hand, the characteristic steps of the present embodiment are modified steps of the steps shown in  FIGS. 5-7 . Namely, the step of forming the ABS sections and the step sections to the step of cutting the row bar  27  to form the separated head sliders  30  are modified. 
       FIGS. 8-21  show the steps of processing the row bar cut from the ALTIC substrate. Note that,  FIGS. 8-17 ,  20  and  21  are perspective views of one of the head sliders formed in the row bar. 
       FIG. 8  shows the abraded row bar  27 . The row bar  27  is constituted by a base member  20   a  composed of ALTIC and the element section  22 , which is formed on a surface (lower surface) of the base member  20   a . The element section  22  are serially formed in the longitudinal direction of the row bar  27  at regular intervals and respectively corresponded to the head sliders formed in the row bar  27 . 
     In  FIG. 9 , terminals  32  of heater circuits are formed on a leading end face (LE surface) of the row bar  27 , to which an air will inflow. The terminals  32  are formed by the steps of: applying resist on the LE surface of the row bar  27 ; optically exposing and developing the resist so as to form concave parts, in each of which the LE surface is exposed as an inner bottom surface and the terminal  32  will be formed, and filling the concave parts with an electrically conductive metal, e.g., copper, by sputtering. 
     Ends of the heater circuits will be connected to end faces of the terminals  32 , which are parallel to an abraded surface (a facing surface)  20   b  of the row bar  27 , in the step of forming the heater circuits. Therefore, the terminals  32  are formed at suitable positions, at which the ends of the heater circuits can be easily connected to the terminals  32  in the step of forming the heater circuits. 
     Note that, the terminals  32  may be formed in the LE surface of the row bar  27  by performing the sputtering from the abraded surface side of the row bar  27 . To easily form the terminals  32 , the resist pattern is formed on the LE surface of the row bar  27  and the sputtering is performed from the LE surface side. 
     In  FIG. 10 , the LE surface of the row bar  27 , on which the terminals  32  have been formed, is coated with an insulating material  34 , e.g., alumina. End faces (upper end faces) of the terminals  32 , which are parallel to the LE surface, are exposed in an upper surface of the insulating material  34 . For example, the LE surface of the row bar  27  may be coated with the insulating material  34  by a photolithographic method. Namely, the upper end faces of the terminals  32 , which are parallel to the LE surface, are coated with resist, the insulating material  34  is applied to the LE surface by sputtering, and then the resist is removed, thereby the upper end faces of the terminals  32  can be exposed in the upper surface of the insulating material  34  coating the LE surface of the row bar  27 . 
       FIGS. 11 and 12  show the steps of forming the ABS sections  14   a  and  14   b  in the abraded surface  20   b  of the row bar  27 . 
     In  FIG. 11 , resist patterns  36   a  and  36   b , whose planar configurations are the same as those of the ABS sections  14   a  and  14   b  to be formed, are formed on the abraded surface  20   b  of the row bar  27 . The resist patterns  36   a  and  36   b , whose configurations are the same as those of the ABS sections  14   a  and  14   b , are formed by coating the abraded surface  20   b  of the row bar  27  with the resist and optically exposing and developing the resist. 
     In  FIG. 12 , the abraded surface  20   b  of the row bar  27  is ion-milled so as to form the ABS sections  14   a  and  14   b  and a groove surface  16 . Since the base member  20   a  is protected by the resist patterns  36   a  and  36   b , the ABS sections  14   a  and  14   b  are level with the abraded surface  20   b . On the other hand, the groove surface  16  is made thinner by ion milling, thereby the groove surface  16  is one-step lower than the ABS sections  14   a  and  14   b.    
     The conventional method of manufacturing the head slider, which has the ABS sections and the step sections, comprises the steps of: ion-milling outer regions of the ABS sections until reaching step surfaces; coating the ABS sections and the step sections with resist; and ion-milling outer regions of the step sections until reaching the groove surface. The ion milling is performed twice for forming the ABS sections, the step sections and the groove surface. On the other hand, the present embodiment is characterized in that the ion milling is performed, beyond the step surfaces, until reaching the groove surface  16  when the ABS sections  14   a  and  14   b  are formed. 
     Note that, when the resist patterns  36   a  and  36   b  are formed, the terminals  32  are coated with the resist pattern  36   a  so as to protect the terminals  32  while performing the ion milling. The resist pattern  36   b  is patterned so as to coat and protect the sensor of the element section  22 . 
     In the present embodiment, the ABS sections  14   a  and  14   b  are separately formed on the element section  22  side and on the terminal  32  side. The ABS sections  14   a  and  14   b  can be optionally formed by patterning the resist. 
       FIGS. 13-15  show the steps of forming the step sections  15   a  and  15   b.    
     In  FIG. 13 , base layers  38   a  and  38   b  of the step sections  15   a  and  15   b  are formed on the groove surface  16 . Planar configurations of the base layers  38   a  and  38   b  are the same as those of the step sections  15   a  and  15   b.    
     In the present embodiment, the heater circuits will be formed in the step sections  15   a  and  15   b . In this case, preferably, the base layer  38   a  and  38   b  are composed of a low-thermal expansion material so as to restrain heat conduction from the heater circuits to the base member  20   a . In case of forming the heater circuit, the base layers  38   a  and  38   b  are composed of an electrically insulating material, e.g., alumina, so as to electrically insulate from the base member  20   a.    
     Note that, in case of forming no heater circuits in the step sections  15   a  and  15   b , the base layers  38   a  and  38   b  may be composed of a good heat conductive material, e.g., metal, or an electrically conductive material. In this case, the base layers  38   a  and  38   b  themselves act as the step sections  15   a  and  15   b.    
     The base layers  38   a  and  38   b  are formed by the steps of: coating the surface of the row bar  27  including the groove surface  16  with resist; patterning the resist to form opening sections corresponding to the base layers  38   a  and  38   b ; and filling the opening sections with the material of the base layers  38   a  and  38   b , e.g., alumina, by sputtering. In  FIG. 13 , the resist pattern is removed after forming the base layers  38   a  and  38   b.    
     In the present embodiment, the heater circuits  40  are formed in the step sections  15   a  and  15   b , so the heater circuits  40  are patterned on the surfaces of the base layers  38   a  and  38   b  after forming the base layers  38   a  and  38   b . The heater circuits  40  are formed by the steps of: coating the base layers  38   a  and  38   b  with resist; patterning the resist according to configurations of the heater circuits  40 ; and filling the resist patterns with an electrically conductive material, e.g., Ti, Ta, by sputtering. By forming the thin and winding heater circuits  40  on the surfaces of the base layers  38   a  and  38   b  with a suitable electrically conductive material, desired heater circuits can be formed. In  FIG. 14 , the heater circuits  40  are formed on the surfaces of the base layers  38   a  and  38   b.    
     The ends of the heater circuits  40  are electrically connected to the terminals  32 . When the resist patterns for forming the heater circuits  40  are formed, the resist patterns are designed to extend the ends of the heater circuits  40  until reaching the end faces of the terminals  32 . Since the end faces of the terminals  32 , which will face a recording medium, are exposed, the heater circuits  40  can be electrically connected to the terminals  32  by sputtering the electrically conductive material after forming the resist patterns. 
     In the present embodiment, the ABS sections  14   a  and  14   b  are formed between the step sections  15   a  and  15   b . Therefore, the base layers  38   a  and  38   b  are formed on the both sides of the ABS sections  14   a  and  14   b . The heater circuits  40  are respectively formed on the base layers  38   a  and  38   b , and the heater circuits  40  are respectively connected to the terminals  32 . Each of the heater circuits  40  is connected to the plus terminal  32  and the minus terminal  32 , so the heater circuits  40  are connected to four of the terminals  32 . 
     After forming the heater circuits  40 , the base layers  38   a  and  38   b  are coated with thermal expansion material layers  42   a  and  42   b , and the heater circuits  40  are encased therein as shown in  FIG. 15 . The thermal expansion material layers  42   a  and  42   b  too may be formed by forming resist patterns according to the planar configurations of the base layers  38   a  and  38   b  and sputtering a thermal expansion material. The thermal expansion material is easily expanded by the heat generated by the heater circuits  40 . 
     For example, the thermal expansion material of the thermal expansion material layers  42   a  and  42   b  is TiW. In case that the thermal expansion material layers  42   a  and  42   b  are composed of an electrically conductive material, insulating layers are provided to the thermal expansion material layers  42   a  and  42   b.    
     The surfaces of the thermal expansion material layers  42   a  and  42   b  become the step surfaces, i.e., an outer surface of the head slider, so the thermal expansion material must be selected in consideration of corrosion resistance and lubricity to the recording medium. Outermost layers of the thermal expansion material layers  42   a  and  42   b  may be composed of a material having enough corrosion resistance, and a plurality of metal layers, which are composed of high-thermal expansion metals, and insulating layers may be formed in the thermal expansion material layers  42   a  and  42   b  as inner layers. 
     Since the outer surfaces of the step sections  15   a  and  15   b  define the step surfaces, thicknesses of the base layers  38   a  and  38   b  and the thermal expansion material layers  42   a  and  42   b  are suitably controlled in the forming steps so as to correctly set heights of the step surfaces with respect to the groove surface  16 . 
       FIGS. 16 and 17  show the steps of forming a heater circuit  41  in the ABS section  14   a . In the present embodiment, the heater circuit  41  is formed in the ABS section  14   a  located closed to the terminals  32 . 
     In  FIG. 16 , a concave part  141  for accommodating the heater circuit  41  in the ABS section  14   a  is formed in the ABS section  14   a . In the present embodiment, the ABS sections  14   a  and  14   b  will be abraded in the following step so as to finish the ABS sections  14   a  and  14   b  having a prescribed height. Therefore, the heater circuit  41  must be formed in and encased by the ABS section  14   a . A depth of the concave part  141  of the ABS section  14   a  is greater than the sum of a thickness of a base layer  38   c  formed in the concave part  141 , a thickness of the heater circuit  41  and a thickness of a thermal expansion material layer  44  coating the heater circuit  41 . The concave part  141  may be formed by ion-milling the ABS section  14   a.    
     In  FIG. 17 , the heater circuit  41  is formed in the ABS section  14   a , and the heater circuit  41  is coated with the thermal expansion material layer  44 . The heater circuit  41  composed of an electrically conductive material is formed into a winding pattern as well as the heater circuits  40 . A process of forming the heater circuit  41  is the same as that of forming the heater circuits  40 . 
     In the present embodiment, the ABS section  14   a  is formed between the step sections  15   a  and  15   b . Therefore, six terminals  32  are formed for the heater circuits  40  and  41  of the step sections  15   a  and  15   b  and the ABS section  14   a , and they are positioned close to the step sections  15   a  and  15   b  and the ABS section  14   a.    
     In the present embodiment, the heater circuit  41  is formed in the ABS section  14   a  located close to the LE surface so as not to badly influence the sensor of the element section  22 . If the heater circuit  41  does not badly influence the sensor of the element section  22 , a heater circuit may be formed in the ABS section  14   b  located close to the element section  22 . 
     In the present embodiment, the heater circuit  41  is formed in the ABS section  14   a  after forming the heater circuits  40  in the step sections  15   a  and  15   b . These steps may be reverse-sequentially performed. 
     Further, in the present embodiment, the heater circuits are formed in the the ABS section  14   a  and the step sections  15   a  and  15   b , but the heater circuits may be formed in only the ABS section(s) or the step sections. 
     As shown in  FIG. 18 , the row bar  27  is adhered to a ceramic tool  29  after forming the heater circuit  41 , and the row bar  27 , which has been adhered to the ceramic tool  29 , is cut to form separated head sliders  30 . 
     Next, the separated head sliders  30  adhered on the ceramic tool  29  are abraded, by an abrasive plate  26 , until the ABSs reach the prescribed height. Simultaneously, the sensors in the element sections  22  are finish-abraded until reaching the prescribed size. By finish-abrading the ABSs in the following step, the height of the ABSs can be accurately controlled. In case that the heater circuit  41  is formed in the ABS section  14   a  like the present embodiment, the ABSs can be highly flattened and the height thereof is accurately defined by the finish-abrading step. 
     The finish-abraded head slider  30  is shown in  FIG. 20 . In this process stage, the head slider  30  is still adhered on the ceramic tool  29 . By cutting the row bar  27  along an intermediate line between the adjacent head sliders  30 , the adjacent head sliders  30  have symmetrical configurations. 
     In the production steps, burrs will be formed while performing the ion milling and the cutting works, and they will stick onto the surfaces of the head sliders  30 . By abrading the ABSs of the separated head sliders  30 , burrs and foreign substances projected form the ABSs can be removed, so that the flat ABSs can become outermost layers of the head sliders  30 . Therefore, damaging the recording medium by burrs, etc. stuck on the ABS can be prevented. 
     In  FIG. 21 , the head slider  30  is adhered on the ceramic tool  29 , and outer surfaces of the head slider  30  are coated with protection films  46 . The protection films  46  are composed of Si, DLC, etc. The protection films  46  are formed on the outer surfaces of the head slider  30  by sputtering a protection material. Therefore, in the head slider  30 , a facing surface, which will face the recording medium, an leading end face, to which an air inflows, and both side faces are coated with the protection film  46 . By entirely coating the outer surfaces of the head slider  30  with the protection films  46 , a problem of falling particles of ALTIC from the head slider  30  can be solved. 
     After coating the outer surfaces of the head sliders  30  with the protection films  46 , the head sliders  30  are peeled from the ceramic tool  29 , so that the independent head sliders  30  can be obtained as products. 
       FIG. 22  is a sectional view taken along a line A-A shown in  FIG. 21 . The ABS of the ABS section  14   a  is the highest surface; the step surfaces of the step sections  15   a  and  15   b  are one-step lower than the ABS of the ABS section  14   a ; and the groove surface  16  is the lowest surface. 
     The step sections  15   a  and  15   b  are constituted by the base layers  38   a  and  38   b , the heater circuits  40  and the thermal expansion material layers  42   a  and  42   b . The ABS section  14   a  is constituted by the base member composed of ALTIC, the base layer  38   c  formed in the concave part, the heater circuit  41  and the thermal expansion material layer  44 . 
     In the present embodiment, the height difference between the ABS and the step surfaces is about 0.1-0.2 μm, and the height difference between the groove surface  16  and the step surfaces is 1-2 μm. The height differences may be optionally designed according to products. 
     In case of mounting the head slider  30 , which has been produced by the method of the above described embodiment, on a head suspension, the sensor of the element section  22  is electrically connected to a read/write control circuit, and the terminals of the heater circuits  40  and  41  are electrically connected to a heater control circuit. By the heater control circuit, the thermal expansion of the ABS section  14   a  and the step sections  15   a  and  15   b  can be controlled, so that the heights of the ABS and the step surfaces can be controlled. 
     In the production method of the present embodiment, the heater circuits  40  and  41  can be easily formed in the the ABS section  14   a  and the step sections  15   a  and  15   b , and the heights of the ABS and the step surfaces can be controlled, so that height variation of the ABS and the step surfaces can be absorbed and the head slider having a superior electromagnetic conversion characteristic can be produced. 
     The invention may be embodied in other specific forms without departing from the spirit of essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.