JP2007184035A - Manufacturing method of head gimbal assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To execute an effective test, and to utilize suspension efficiently by determining structural characteristics of the suspension appropriately, when repeatedly attaching and detaching a plurality of head sliders to and from one suspension for testing. <P>SOLUTION: The suspension 120 for testing is prepared, the structural characteristics of the suspension 120 for testing are measured, a head slider 105 is mounted to the suspension 120 for testing which has measured structural characteristics of a reference level as one condition. The assembly of the head slider 105 and the suspension 120 for testing is tested, and the head gimbal assembly is assembled by using the tested head slider 105. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a head gimbal assembly, and more particularly to detection of a state of a test suspension in the manufacturing process.

  As data storage devices, devices using various types of media such as optical disks and magnetic tapes are known. Among them, a hard disk drive (HDD) is widely used as a computer storage device, and is one of the storage devices indispensable in the current computer system. Furthermore, not only computer systems, but also the use of HDDs, such as moving image recording / playback devices, car navigation systems, mobile phones, and removable memories used in digital cameras, are increasingly expanding due to their superior characteristics. .

  The HDD includes a magnetic disk for storing data and a head slider for accessing the magnetic disk. The head slider has a head element portion that reads and / or writes data from and to the magnetic disk, and a slider on which the head element portion is formed. The head element section includes a recording element that converts an electric signal into a magnetic field according to recording data on the magnetic disk and / or a reproducing element that converts a magnetic field from the magnetic disk into an electric signal. The HDD further includes an actuator that moves the head slider to a desired position on the magnetic disk. The actuator is driven by a voice coil motor (VCM), and rotates about the rotation axis to move the head slider in the radial direction on the rotating magnetic disk. As a result, the head element section can access a desired track formed on the magnetic disk and perform data read / write processing.

  The actuator includes an elastic suspension, and the head slider is fixed to the suspension with an adhesive. The pressure due to the viscosity of the air between the ABS (Air Bearing Surface) surface of the head slider facing the magnetic disk and the rotating magnetic disk balances with the pressure applied in the direction of the magnetic disk by the suspension. • The slider can fly over the magnetic disk with a certain gap.

  This head slider / suspension assembly is called a head gimbal assembly (HGA). FIG. 13 shows an example of the HGA, and shows the structure of the HGA as viewed from the recording surface side of the magnetic disk. As shown in FIG. 13, the HGA 400 includes a head slider 401, a suspension 402, and a trace 403 that is transmission wiring. The suspension 402 includes a flexible gimbal 404 that holds the head slider 401 on the side facing the magnetic disk, a load beam 405 that holds the gimbal 404 on the side facing the magnetic disk, and a mount plate 406. Yes. The HGA 400 shown in the figure is a load / unload type, and includes a tab 407 for retracting to the ramp mechanism at the tip of the load beam 405. A plurality of terminals connected to the head element portion are formed on the front surface (tab side) of the head slider 401. Each terminal and each wiring of the trace 403 are formed by using solder or gold ball bonding. It is connected.

  In manufacturing the HGA, a test called a dynamic electric test (DET) is performed. The DET sets the HGA in the test apparatus and performs actual read / write processing on the rotating magnetic disk. Thus, the flying characteristics and recording / reproducing characteristics of the head slider are evaluated. The HGA that satisfies the specifications in the DET proceeds to the next manufacturing process, and the HGA that is determined to be rejected is discarded. Therefore, when the head slider does not meet the specifications, the suspension to which the head slider is fixed is also discarded, resulting in a loss in manufacturing the HGA.

  In order to eliminate the loss of this suspension in the manufacture of HGA, a DET device in which a head slider can be attached and detached has been proposed (see, for example, Patent Document 1). As described above, by using the test apparatus with the head slider alone, DET can be performed before the head slider is mounted on the suspension, and the loss of the suspension due to the failure of the head slider can be prevented.

Alternatively, a technique for removing a defective head slider from the suspension by improving an adhesive for fixing the head slider to the suspension has been proposed (see, for example, Patent Document 2). DET evaluates the characteristics of the head slider in the HGA state. The adhesive is in a gel state at a low temperature, becomes a molten state at a high temperature, and further cures at a high temperature. The head slider and the suspension are temporarily fixed with an adhesive in a gel state, and DET is executed in this state. If the head slider is defective, the adhesive is heated to a molten state, and the head slider is removed from the suspension. When the head slider satisfies the specifications, the adhesive is thermally cured and this connection is made.
JP 2004-86976 A JP 2002-150734 A

  However, it is difficult for a test apparatus dedicated to the head slider to perform DET under exactly the same conditions as the HGA. As recording density increases and track pitch and head sliders become finer, it is required to perform DET under conditions that more closely match the actual usage conditions. Test equipment dedicated to head sliders that do not use ordinary suspensions is difficult to meet such demands. In particular, since normal suspensions that can be used for product HDDs are not used, high-speed off-track testing is possible. Measurement is impossible. Further, when a special adhesive is used as described above, a complicated heat treatment is required for attaching and detaching the head slider. Further, the temporary fixing with the gel adhesive does not necessarily obtain a sufficient strength, and the head slider may be displaced from a desired position.

  In order to solve the above problems, it is conceivable to use a test suspension to which the head slider can be attached and detached. DET is performed by fixing the head slider on the suspension only by clamping with the clamp, connection terminal and stopper formed on the suspension. In addition to being able to perform DET under the same conditions as a normal suspension, since it is fixed only by clamping, the head slider and the suspension can be easily attached and detached.

  However, the inventors have found that in such a configuration, by repeatedly attaching and detaching a plurality of head sliders to one suspension, the suspension, particularly the gimbal, is deformed and an appropriate test cannot be performed. I found it. For example, the connection terminal and the stopper are worn or deformed by attaching and detaching the head slider. Or the clamp which presses and hold | maintains it can deform | transform by repeating attachment / detachment of a head slider. Furthermore, the gimbal main body may be deformed during the operation of attaching / detaching the head slider.

  Due to wear and deformation of the connection terminal, the contact between the pad of the head slider and the connection terminal may be insufficient. As a result, the necessary electrical connection between the head element portion and the connection terminal cannot be obtained. Alternatively, the wear and deformation of the stopper are remarkable, and if the distance between the stopper and the clamp is widened, a sufficient clamping force of the head slider cannot be obtained, and the head slider cannot be securely held on the gimbal. Further, in order to perform accurate characteristic evaluation in DET, it is important that the head slider is accurately positioned with respect to the dimple. However, due to wear and deformation of the stopper, the head slider is placed on the gimbal. Deviation occurs in the position where the is fixed.

  When the clamp is deformed, the elastic force of the clamp is reduced, and the head slider cannot be held with a necessary clamping force. As a result, the position of the head slider is displaced, or there is a risk that the head slider falls during the test.

  Further, it is conceivable that the height and angle (posture angle) with respect to the load beam change due to the deformation of the gimbal. This affects the flying characteristics of the head slider, making it impossible to accurately evaluate the characteristics.

  As described above, the number of times that the suspension can be used has a limit (use limit). Suspensions that have reached the end of their service life must be replaced, but there are individual differences in the number of service life of the suspension, and it is difficult to judge the replacement time. Sufficient structural characteristics are required for the suspension to be properly tested, while for the effective use of the suspension, it should be used as close as possible to the service life. Is preferred.

  The present invention has been made against the background of such circumstances, and one of its purposes is the structural characteristics of the suspension when a plurality of head sliders are repeatedly attached to and detached from a single suspension for testing. Make good judgments to achieve effective test execution and effective use of the suspension.

  A first aspect of the present invention is a method of manufacturing a head gimbal assembly comprising a head slider and a suspension that holds the head slider, the load beam, a tongue for arranging the head slider, and A test suspension having a spring-like clamp for pressing and holding the head slider on the tongue, and a flexible gimbal fixed on the surface of the load beam; The head slider is mounted on the test suspension and the assembly of the head slider and the test suspension is tested on the condition that the measured structural characteristics are at a reference level. Assemble the head gimbal assembly using the tested head slider. Is shall. As a result, when multiple heads and sliders are repeatedly attached to and detached from a single suspension, the structural characteristics of the suspension are properly determined, and effective test execution and effective use of the suspension can be achieved. it can.

  In the above aspect, it is preferable that a relative height of the tongue with respect to the load beam is measured as a structural characteristic of the test suspension.

  In the above aspect, it is preferable that the posture angle of the tongue is measured as the structural characteristic of the test suspension.

  In the above aspect, as a structural characteristic of the test suspension, it is preferable to measure a distance between the clamp and the stopper that sandwiches the head slider with the clamp.

  Said aspect WHEREIN: It is preferable to measure the distance between the said stopper and the said clamp using the relationship with respect to the reference position of the said clamp, and the relationship with respect to the said reference position of the said stopper.

  In the above aspect, it is preferable to measure a distance between the clamp and a reference position as a structural characteristic of the test suspension.

  In the above aspect, as a structural characteristic of the test suspension, it is preferable to measure a distance between a stopper that sandwiches the head slider with the clamp and a reference position.

  In the above aspect, as a structural characteristic of the test suspension, it is preferable to measure a distance between a connection terminal that contacts the pad of the head slider and transmits an electric signal and a reference position.

  In the above aspect, the positional deviation of the head slider fixed on the tongue using the clamp with respect to the dimple supporting the tongue is measured, and when the deviation exceeds a reference value, another test suspension It is preferable to mount the head slider.

  In the above aspect, when the continuity between the head slider fixed on the tongue using the clamp and the probe abutting on the pad of the head slider is measured and is not conductive The head slider can be mounted on another test suspension.

  A second aspect of the present invention is a method of manufacturing a head gimbal assembly comprising a head slider and a suspension for holding the head slider, the load beam, a tongue for arranging the head slider, and A test suspension comprising a flexible gimbal having a spring clamp for pressing and holding the head slider on the tongue and fixed on the surface of the load beam; Is fixed on the tongue using the clamp, and the positional deviation of the head slider fixed on the tongue with respect to the dimples supporting the tongue is measured, and the positional deviation is within the standard. One of the test suspensions is used, and if the displacement exceeds the reference, another test suspension is used. It said head slider is mounted on Deployment to test the assembly of the slider and the test suspension is intended to assemble the head gimbal assembly using the tested slider. As a result, when multiple heads and sliders are repeatedly attached to and detached from a single suspension for testing, the structural characteristics of the suspension should be appropriately determined to achieve effective test execution and effective use of the suspension.

  In the above aspect, the positional deviation is preferably measured using a relationship between a reference position on the head slider and a reference position on the load beam.

  In the above aspect, before mounting the head slider, the distance between the clamp and the stopper that clamps the head slider is measured, and the distance is outside the reference. The head slider is preferably mounted on another test suspension.

  According to the present invention, in the case where a plurality of head sliders are repeatedly attached to and detached from a single suspension, the structural characteristics of the suspension are appropriately determined, and effective test execution and effective use of the suspension are realized. To do.

  Hereinafter, embodiments to which the present invention can be applied will be described. In addition, in each drawing, the same code | symbol is attached | subjected to the same element and the duplication description is abbreviate | omitted as needed for clarification of description. The present embodiment relates to a suspension state inspection technique for holding a head slider in a dynamic electric test (DET) of a head slider in a manufacturing process of a hard disk drive (HDD). The DET of this embodiment performs a test by mounting a head slider on a test suspension having the same configuration as that of a suspension used in a HDD as a product, and evaluates the characteristics. In this embodiment, the suspension is held by sandwiching the head slider. One of the features of this embodiment is to measure the structural characteristics of the suspension. In particular, the suspension state of the head slider can be inspected and the electrical connection with the head slider can be inspected. In this specification, the assembly of the suspension and the head slider is called a head gimbal assembly (HGA).

  First, the overall configuration of the HDD will be described. FIG. 1 is a plan view schematically showing the configuration of HDD 100 according to the present embodiment. The HDD 100 includes a magnetic disk 101 as a recording disk for recording data. The magnetic disk 101 is a non-volatile memory that records data by magnetizing a magnetic layer. Each component of the HDD 100 is accommodated in the base 102. The base 102 constitutes a disk enclosure by being fixed via a cover (not shown) and a gasket (not shown) that close the upper opening of the base 102, and can accommodate each component of the HDD 100 in a sealed state. .

  The magnetic disk 101 is fixed to a spindle motor (SPM) 103. The head slider 105 includes a head element unit for writing and / or reading data to / from the magnetic disk 101 with respect to data input / output with a host (not shown). The head element unit includes a recording element that converts an electric signal into a magnetic field according to data stored in the magnetic disk 101 and / or a reproducing element that converts a magnetic field from the magnetic disk 101 into an electric signal, and a recording element and / or reproducing element. Has a slider formed on the surface.

  The actuator 106 holds and moves the head slider 105. The actuator 106 is rotatably held on a rotary shaft 107 and is driven by a VCM (voice coil motor) 109 as a drive mechanism. The actuator 106 includes constituent members coupled in the order of the suspension 110, the arm 111, the coil support 112, and the flat coil 113 from the tip in the longitudinal direction where the head slider 105 is disposed. The configuration of the suspension 110 will be described in detail later. The VCM 109 includes a flat coil 113, a stator magnet (not shown) fixed to the upper stator magnet holding plate 114, and a lower stator magnet (not shown).

  The magnetic disk 101 is integrally held by an SPM 103 fixed to the bottom surface of the base 102 and is rotationally driven by the SPM 103 at a predetermined speed. The magnetic disk 101 rotates counterclockwise in FIG. The VCM 109 rotates the actuator 106 in the short direction about the rotation shaft 107 in accordance with a drive signal sent from the controller (not shown) to the flat coil 113. Accordingly, the actuator 106 can move the head slider 105 on the magnetic disk 101 or move the head slider 105 to the outside of the magnetic disk 101.

  In order to read / write data from / to the magnetic disk 101, the actuator 106 moves the head slider 105 over the data area on the surface of the rotating magnetic disk 101. As the actuator 106 rotates, the head slider 105 moves along the radial direction of the surface of the magnetic disk 101. As a result, the head slider 105 can access a desired track. A signal between the head slider 105 and the controller is transmitted by the trace 201 and the FPC 117 which are transmission wirings. In the head slider 105, pressure due to the viscosity of air between the ABS (Air Bearing Surface) surface of the slider facing the magnetic disk 101 and the rotating magnetic disk 101 is applied in the direction of the magnetic disk 101 by the suspension 110. By balancing with the pressure, the head slider 105 floats on the magnetic disk 101 with a certain gap.

  When the rotation of the magnetic disk 101 stops, the actuator 106 retracts the head slider 105 from the data area to the ramp mechanism 115. The actuator 106 rotates in the direction of the ramp mechanism 115 and the tab 116 at the tip of the actuator rests on the parking surface on the ramp mechanism 115, whereby the head slider 105 is unloaded.

  Note that the present invention can also be applied to a CSS (Contact Start and Stop) system in which the head slider 105 retreats to a zone disposed on the inner periphery of the magnetic disk 101 when data writing / reading processing is not performed. Is possible. In the above description, for the sake of simplicity, a single-sided hard disk drive having a single magnetic disk 101 is described. However, the HDD 100 can include one or a plurality of double-sided storage magnetic disks. .

  As described above, the head slider 105 is a DET target in the manufacturing process before being mounted on the HDD 100. In DET, the head slider 105 is mounted on a test suspension having the same configuration as the suspension 110 to form an HGA, the HGA is set in a test apparatus, and an actual read / write is performed on a rotating magnetic disk. Process. Thus, the flying characteristics and recording / reproducing characteristics of the head slider 105 are evaluated.

  Further, in the present embodiment, when the head slider 105 is DETed, before the head slider 105 is mounted on the test suspension, it is inspected whether the test suspension is in a state where an accurate characteristic evaluation can be performed in the DET. FIG. 2 shows the DET process according to the present embodiment including the inspection of the test suspension. As shown in the flowchart of FIG. 2, first, as an inspection of the test suspension, an initial state is confirmed (S201). Details of the contents to be confirmed here will be described later.

  Next, the head slider 105 is mounted on the test suspension to configure the HGA (S202). The head slider 105 is detachably attached to the test suspension. The head slider 105 holding mechanism of this test suspension will be described in detail later. Next, the state of the head slider 105, such as the position where the head slider 105 is placed on the test suspension, is confirmed (S203). Details of the contents to be confirmed here will be described later.

  It is determined whether or not the state confirmed in S203 is appropriate (S204). If it is determined that the state is not appropriate, the test suspension is replaced (S205), and the initial state of the test suspension is confirmed again. (S201). If it is determined that the state confirmed in S203 is appropriate, the configured HGA is set in the DET test apparatus, and DET is executed (S206). When DET is completed, the head slider 105 is removed from the test suspension 120 (S207).

  If the DET evaluation result in S206 is “error (defective, NG)”, the head slider 105 is discarded. When the evaluation result of DET in S206 is “pass (good, OK)”, the head slider 105 is removed from the test suspension, and the head slider 105 is mounted on the product suspension. Specifically, the head slider 105 and the suspension 110 are fixed with an adhesive, and the terminal portions are electrically and physically connected by solder ball bonding or gold ball bonding. Thereafter, the HGA is mounted on the HDD 100 as a product.

  If there is no more head slider 105 to perform DET (S208), the process is terminated. If there is still a head slider 105 to perform DET (S208), the state of the test suspension is confirmed again (S209). The items confirmed here are the same as the items confirmed in S201. Based on the result of checking the state of the test suspension and the initial state confirmed in S201, it is determined whether or not the test suspension can be continuously used for DET, that is, whether or not the service life limit has been reached. (S210).

  If the test suspension can be used continuously, a new head slider 105 to be subjected to DET is attached (S202), and the state of the attached head slider is confirmed (S204). If it is determined (S204), DET is performed (S206). If continuous use is impossible, the test suspension is replaced with a new one (S211), the initial state of the new test suspension is confirmed (S201), and DET is subsequently performed. In this way, by inspecting each time whether or not the test suspension can be properly evaluated, it is possible to achieve an appropriate DET for each head slider and to appropriately determine the endurance limit of the test suspension. And the test suspension can be used effectively.

  With reference to FIG. 3, the structure of HGA200 used in DET of this form is demonstrated. FIG. 3A is a plan view showing a partial configuration of the HGA 200 in a state used for DET, and shows the configuration of the HGA 200 viewed from the magnetic disk side. FIG. 3B is a side view thereof. In addition, the part which is not shown by FIG. 3 is the structure similar to the conventional HGA, and abbreviate | omits description. In this embodiment, the HGA 200 includes a plurality of constituent members, and includes a head slider 105, a test suspension 120, and a trace 201. The test suspension 120 is composed of a plurality of components and includes a gimbal 202 and a load beam 203.

  The trace 201 transmits a signal of the head element unit in the head slider 105. In FIG. 3, two leads for the reproducing element and two leads for recording are shown. The load beam 203 is formed of stainless steel or the like and functions as a precise thin plate spring. A tab 116 is formed at the front end of the load beam 203 on the front side in the longitudinal direction (on the counter-rotating shaft 107 side). The load beam 203 has elasticity to generate a load that opposes the flying force of the head slider 105. This load and the flying force of the head slider 105 are balanced, so that the head slider 105 floats at a desired height.

  The gimbal 202 is welded to the surface of the magnetic disk 101 of the load beam 203 by laser spot welding. An opening 222 is formed in the front part of the gimbal 202. A tongue-shaped gimbal tongue 223 protruding toward the center of the opening 222 is formed at the center of one side of the front side (tab 116 side) of the opening 222. The head slider 105 is disposed on the gimbal tongue 223 that protrudes from the front side of the opening 222 to the rear side (inflow side of the head slider 105). The head slider 105 is held by a spring clamp 224 and a stopper 227 formed on the gimbal 202. The holding mechanism for the head slider 105 will be described in detail later.

  As shown in FIG. 3B, the load beam 203 is formed with a dimple 231 that protrudes toward the gimbal 202 side (head slider 105 side (upward in the drawing)) at a position facing the head slider 105. ing. The gimbal tongue 223 is supported at one point by the dimple 231 of the load beam 203. The gimbal arm 225 is warped, and the gimbal tongue 223 is pressed against the dimple 231 by an elastic force. A reference hole 232 is formed in the load beam 203. The reference hole 232 is formed at a predetermined position on the load beam 203. Accordingly, the positional relationship between the reference hole 232 and the dimple 231 or the gimbal tongue 223 is also determined.

  As described above, the head slider 105 is detachably held on the gimbal tongue 223. A clamp 224 having a bent portion and having a spring property is formed at the rear end portion of the gimbal tongue 223, that is, the inflow side of the head slider 105. The spring clamp 224 is formed to face the inflow side surface 151 of the head slider 105. The spring clamp 224 contacts the inflow side surface 151 and presses the surface in the forward direction (outflow side of the head slider 105). The stopper 227 supports the head slider 105 so as to resist the pressing force of the spring clamp 224. That is, the head slider 105 is sandwiched between the spring clamp 224 and the stopper 227 by these pressing forces.

  Four terminals (not shown in FIG. 3) are formed on the front surface of the head slider 105, that is, the outflow side surface 152, which is the opposite side of the spring clamp 224. Each terminal is connected to the head element portion. Each of the connection terminals 221 of the gimbal 202 is in contact with each terminal of the head slider 105. In the gimbal 202, an opening 226 is formed in front of the outflow side surface 152, and the connection terminal 221 is formed so as to protrude into the opening 226. In order to perform accurate characteristic evaluation, it is important that the head slider 105 is aligned with the dimple 231 and the stopper 227 performs this positioning. Note that the suspension / HGA inspection process of the present embodiment is not limited to the suspension configured as described above. For example, in the above description, the stopper 227 and the connection terminal 221 are formed as separate members, but the connection terminal 221 may have a function as the stopper 227.

  In this way, when the head slider 105 is mounted on the test suspension 120, a slider mounting device is used. The slider mounting device has a function of allowing access to a spring clamp 224 provided on the gimbal tongue 223, and this function controls the distance between the stopper 227 and the spring clamp 224 on the gimbal tongue 223. The head slider 105 is mounted or the mounted head slider 105 is removed.

  Next, a specific method for checking and inspecting the state of the test suspension 120 will be described. The method for checking and inspecting the state of the test suspension 120 according to the present embodiment is mainly the first method for inspecting the clamping state and the electrical connection state of the head slider 105 on the gimbal tongue 223, and mainly the gimbal. The second method for inspecting the inclination and height of the tongue 223 or the head slider 105 with respect to the load beam 203 is divided. The first method is performed by recognizing the surface of the test suspension 120 facing the magnetic disk, that is, the surface provided with the spring clamp 224, the stopper 227, etc. as an image and analyzing the position of each part. The second method is performed by irradiating the surface of the test suspension 120 facing the magnetic disk with laser light, and detecting and analyzing the reflected light.

  In the flowchart shown in FIG. 2, the first method and the second method are used in S201, S203, and S209. First, the first method will be described. In the first method, as shown in FIG. 4, the longitudinal direction of the test suspension 120 is defined as the X-axis, and the direction is parallel to the head slider 105 mounting surface and perpendicular to the X-axis. Is defined as the Y axis. According to the defined coordinates, coordinate data indicating the coordinates of each part of the test suspension 120 is generated. By analyzing the generated coordinate data with reference to the initial state data indicating the initial state of each part of the test suspension 120, the state data indicating the state of the test suspension 120 is generated. The generated state data is evaluated by comparing with the reference value data indicating the state in which the test suspension 120 reaches the service life limit, and evaluation result data indicating whether or not the test suspension 120 can be continuously used is generated. .

  The configuration and operation of the suspension evaluation apparatus 1 according to the first method will be described with reference to FIG. FIG. 5 is a block diagram showing the suspension evaluation apparatus 1 for confirming and inspecting the state of the test suspension 120 in the first method. The suspension evaluation apparatus 1 according to the first method includes a CCD camera 2 that captures an inspection surface of a test suspension 120, and a computer 3 that analyzes input information and generates an evaluation result.

  As the computer 3, a normal personal computer (PC) or a workstation can be used. Image data (actual image data 321) of the test suspension 120 from the CCD camera 2 is stored in the main memory 32 via the I / O interface 34. Further, the actual image data 321 is also recorded in the nonvolatile storage device 33 for later use. As an interface for capturing image data from the CCD camera 2, a capture board is typically used. A DRAM can be typically used as the main memory 32 and a hard disk drive (HDD) can be typically used as the nonvolatile storage device 33.

  A CPU 31 is mounted in the computer 3. The CPU 31 operates according to the commands of the operating system and the test suspension evaluation program stored in the nonvolatile storage device 33, thereby executing each process for the test suspension evaluation. The program is loaded from the nonvolatile storage device 33 to the main memory 32 and executed by the CPU 31. Although not shown in the figure, the computer 3 is mounted with a controller connected to the CPU 31 and the main memory 32 via a bus, and a mouse or keyboard for inputting data to these, or a display for image output. Or connect a printer. In order to communicate with other computers, the computer 3 can be connected to a network via a communication adapter.

  Next, the operation of the apparatus according to the first method will be described using the flowchart shown in FIG. First, the case where the test suspension 120 in the state where the head slider 105 is not mounted, which is performed in S201 and S209, will be described. First, initial state data indicating the initial state of each part of the test suspension 120 to be inspected is input (S601). In this processing, the CPU 31 that operates according to the program functions as the read image data conversion unit 311. Based on the actual image data 321 of the test suspension 120 imaged by the CCD camera 2, the read image data conversion unit 311 recognizes the coordinates of each part of the test suspension 120 and converts them into coordinate data. Thereby, initial coordinate data is generated. The coordinates of the initial coordinate data generated here are defined for each image data, and the same position of the suspension 120 does not always match between the coordinate data.

  FIG. 7A shows an example of information generated as coordinate data 322 and initial coordinate data. As the coordinate data, the coordinates (a) of the reference hole 232 formed in the load beam 203 shown in FIG. 4 and the spring clamp that is the contact surface of the spring clamp 224 with the head slider 105 are generated. The coordinates (b) of the clamping surface 224, the coordinates (c) of the clamping surface of the stopper 227 that is the contact surface of the stopper 227 with the head slider 105, and the terminal portion of the head slider 105 that is the end of the connection terminal 221 Is the coordinate (d) of the contact point. The initial coordinate data obtained in this way is standardized by the coordinate data analysis unit 312 with the coordinates of the reference hole 232 as the origin, and initial state data 323 shown in FIG. 7B is generated. Details will be described later.

  Next, reference value data 325 for determining the replacement timing of the test suspension 120 is input (S602). The reference value data 325 is manually input using a user interface such as a keyboard (not shown). Information input as the reference value data 325 is stored in the nonvolatile storage device 33. The information stored as the reference value data 325 is information shown in FIG. 7C, for example. Details will be described later.

  Next, the test suspension 120 to be inspected is imaged by the CCD camera 2, and coordinate data 322 is generated from the actual image data 321 (S603). This process is the same as S601, but is stored not as initial coordinate data 323 but as coordinate data 322. Then, the generated coordinate data 322 is normalized with the coordinate (a) of the reference hole 232 as the origin, and further analyzed with reference to the initial state data 323, thereby obtaining state data 324 indicating the state of the test suspension 120. Generate (S604). In this processing, the CPU 31 functions as the coordinate data analysis unit 312, compares and analyzes the coordinate data 322 and the initial state data 323, and generates state data 324.

  Information included in the state data 324 is, for example, information illustrated in FIG. That is, the position (e) of the holding surface of the stopper 227 when the reference hole 232 is the origin, the holding width (f) that is the distance between the spring clamp 224 that holds the head slider 105 and the stopper 227, and the reference hole 232 The position (g) of the clamping surface of the spring-like clamp 224 with respect to the origin, the degradation level (h) of the clamping force compared with the initial state of the test suspension 120, the terminal portion of the head slider 105 and the connection terminal 221 And information such as the electrical connection level (i).

The position (e) of the clamping surface of the stopper 227 can be obtained by normalizing the coordinate (c) of the clamping surface of the stopper 227 with the coordinate (a) of the reference hole 232 as the origin. The clamping width (f) can be obtained from the distance between the clamping surface of the spring clamp 224 and the clamping surface of the stopper 227. The position (g) of the clamping surface of the spring clamp 224 can be obtained by normalizing the coordinate (b) of the clamping surface of the spring clamp 224 with the coordinate (a) of the reference hole 232 as the origin. The process described here is the same as the process for generating the initial state data 323 shown in FIG. That is, the position of the clamping surface of the stopper 227 obtained based on the initial coordinate data is (e _pre ), the clamping width is (f _pre ), and the position of the clamping surface of the spring clamp 224 is (g _pre ). is there.

The degradation level (h) of the clamping force can be obtained by comparing and analyzing (e) and (e _pre ), (f) and (f _pre ), (g) and (g _pre ), respectively. The spring clamp 224 is considered to have a sandwiching surface (g) shifted toward the rotating shaft 107 as the spring stretches and its elastic force deteriorates. Further, it is considered that the stopper 227 is worn or deformed, and the holding surface (e) is shifted to the counter-rotating shaft 107 side. Along with this, the clamping width (f) is considered to increase. Therefore, by performing the above comparison and analysis, it is possible to know the deterioration level of the holding force for holding the head slider 105, that is, the degree of deterioration of the elastic force.

  The electrical connection level (i) can be obtained by analyzing the contact point position (d) of the connection terminal 221 and the clamping surface position (c) of the stopper 227. It is considered that the contact point position (d) of the connection terminal 221 is worn or deformed by repeatedly attaching and detaching the head slider 105 and shifts to the counter-rotating shaft 107 side. On the other hand, the position of the terminal of the head slider 105 can be known from the clamping surface position (c) of the stopper 227. Therefore, by the positional relationship between the contact point position (d) of the connection terminal 221 and the clamping surface position (c) of the stopper 227, it is determined how much the contact force of the connection terminal 221 contacts the terminal of the head slider 105. Can do.

  When the state data 324 is generated as described above, the evaluation result data 326 is generated by comparing the state data 324 with the reference value data 325 for evaluation (S605). In this processing, the CPU 31 functions as the evaluation data calculation unit 313, evaluates the test suspension 120 based on the state data 324, and generates evaluation result data 326. The information included in the reference value data 325 indicates the allowable limit value of the information included in the state data 324 as shown in FIG. An example of information included in the evaluation result data 326 is shown in FIG. That is, in the evaluation result data 326, as a result of comparing the state data 324 with the reference value data 325, information indicating whether or not each value included in the state data 324 is within the allowable range is indicated by ○ or ×. included.

  As a result of comparing the state data 324 and the reference value data 325, the evaluation data calculation unit 313 determines whether each value of the state data 324 is within an allowable range indicated by the reference value data 325 (whether it is within the reference or outside the reference). By judging, the state of the test suspension 120 is evaluated, and whether each value is within the allowable range is judged by ○ or ×. Then, based on the determination result of each value, it is determined whether or not the test suspension 120 to be inspected can be continuously used, and the evaluation result data 326 is generated. Typically, if any one of the conditions is out of the standard, the test suspension 120 is replaced. This also applies to the following inspection.

  The evaluation result data 326 obtained in this way is displayed on a display (not shown) connected to the computer 3. The operator refers to the evaluation result of the test suspension 120 displayed on the display and determines whether or not the test suspension 120 needs to be replaced.

  Next, the case where the test suspension 120 with the head slider 105 mounted thereon is inspected in S203 will be described. Also in this case, the inspection is performed along the same flow as in FIG. 6, using the same device as that shown in FIG. In the state where the head slider 105 is mounted, the position where the head slider 105 is held on the gimbal tongue 223 is measured and evaluated. More specifically, it is determined whether or not the positional relationship between the head slider 105 and the dimple 231 is appropriate.

  That is, the information generated as the coordinate data 322 shown in FIG. 5 includes the coordinates of the reference hole 232 and one or more predetermined coordinates of the head slider 105. Both the reference hole 232 and the dimple 231 are formed on the load beam 203, and the distance between them is a predetermined dimension. Therefore, the positional relationship between the head slider 105 and the dimple 231 can be known by analyzing the positional relationship between the position of the head slider 105 and the position of the reference hole.

  The position of the head slider 105 may be a position of the head slider 105 having a specific position on the ABS surface of the head slider 105. By comparing the head slider 105, the dimple 231 and the reference data obtained in this way, the amount of deviation in the positional relationship between the head slider 105 and the dimple 231 can be obtained.

  The reference value data 325 shown in FIG. 5 includes information indicating the limit value of the positional relationship between the head slider 105 and the dimple 231. Therefore, by comparing the state data 324 and the reference value data 325, it can be determined whether or not the head slider 105 and the dimple 231 are in an appropriate positional relationship. Evaluation result data 326 is generated according to this determination result. Since the head slider 105 has a product variation, proper DET can be performed by measuring the positional deviation after the head slider 105 is mounted.

  Further, the head slider holding surface of the spring clamp 224 can be recognized as an X, Y plane line. Thereby, it is possible to know how much the head-slider clamping surface is inclined from the direction parallel to the Y-axis, and the bias of the clamping force of the head-slider 105 by the spring clamp 224 can be obtained. Further, the clamping surfaces of the head slider 105 of the stopper 227a and the stopper 227b can be obtained separately. Thereby, the inclination of the head slider 105 in the state held by the gimbal tongue 223 can be known. In order to measure the deterioration of the spring clamp 224, it is preferable to use the contact surface with the head slider 105 as a measurement point, but it is also possible to use another reference point on the spring clamp 224 as a measurement point. .

  Next, the second method will be described. In the second method, as shown in FIG. 8, the longitudinal direction of the test suspension 120 and parallel to the gimbal 202 mounting surface of the load beam 203 is taken as the X axis, and the load beam 203 The direction perpendicular to the X axis is defined as the Y axis, and the direction perpendicular to the gimbal 202 loading surface of the load beam 203 is defined as the Z axis. Further, the loading surface of the load beam 203 on the gimbal 202 is set as the origin in the Z-axis direction. According to the defined coordinates, the position coordinates of a plurality of predetermined points of the test suspension 120 are specified.

  Based on the generated coordinate sequence data, state data indicating the height and angle (posture angle) of the gimbal tongue 223 or the head slider 105 with respect to the load beam 203 is generated. The generated state data is evaluated by comparing the initial state data indicating the initial state of the test suspension 120 and the reference value data indicating the state where the test suspension 120 reaches the end of its service life. Evaluation result data indicating whether continuous use is possible is generated.

  The configuration and operation of the suspension evaluation apparatus 4 according to the second method will be described with reference to FIG. The suspension evaluation apparatus 4 according to the second method irradiates the inspection surface of the test suspension 120 with laser light, receives the reflected light, and generates coordinate information based on the received reflected light. 5 and a computer 3 that analyzes input information and generates an evaluation result. The overall configuration of the computer 3 is the same as that shown in FIG.

  Next, the operation of the apparatus according to the second method will be described using the flowchart shown in FIG. A case where the test suspension 120 in which the head slider 105 is not mounted, which is performed in S201 and S209, is described. First, initial state data indicating the initial state of the gimbal tongue 223 of the test suspension 120 to be inspected is input (S101). A specific method for generating the initial state data 623 and information included will be described later. The generated initial state data 623 is stored in the nonvolatile storage device 63.

  Next, reference value data 624 for determining the replacement timing of the test suspension 120 is input (S102). The reference value data 624 is manually input using a user interface (not shown). Information input as the reference value data 624 is stored in the nonvolatile storage device 33. Information stored as the reference value data 624 is, for example, information illustrated in FIG. Details will be described later.

  Next, the optical analyzer 5 irradiates the inspection surface of the test suspension 120 to be inspected with laser light and receives the reflected light. Then, coordinate information is generated based on the received reflected light. By repeating this process over the entire gimbal tongue 223, the Z coordinate based on the X and Y coordinates of each part of the gimbal tongue 223 is obtained, and the coordinate string data 621 is generated (S103). The coordinate string data 621 includes information on a combination of X, Y, and Z coordinates as shown in FIG. 11C, for example.

  Next, based on the generated coordinate string data 621, state data 622 is generated (S104). In this process, the CPU 61 that operates according to the program functions as the state data generation unit 611. The state data generation unit 611 analyzes the information included in the coordinate sequence data 621, and calculates the inclination and height of the plane drawn by the sequence of coordinates included in the information with respect to the load beam 203 plane. The information included in the state data 622 is information shown in FIG. 11A, for example. That is, the inclination (j) and height (k) of the gimbal tongue 223 with respect to the load beam 203. Here, the initial state data 623 is also generated by S103 and S104 in the same manner as the state data 622, and an example of the included information is shown in FIG. Here, the inclination (j) is, for example, an inclination of the head slider 105 mounting surface with respect to the load beam 203 surface.

  When the state data 622 is generated as described above, the evaluation result data 625 is generated by comparing the state data 622 with the initial state data 623 and the reference value data 624 (S105). In this processing, the CPU 61 functions as the evaluation data calculation unit 612, evaluates the test suspension 120 based on the state data 622, and generates evaluation result data 625.

The information included in the reference value data 624 indicates an allowable limit width centered on the initial state data 623 of the information included in the state data 622, as shown in FIG. That is, the slope (j) of the gimbal tongue 223 is _{defined as} (j _pre ) ± (j _lim ), and the height (k) of the gimbal tongue 223 is defined as (k _pre ) ± (k _lim ). . An example of information included in the evaluation result data 625 is shown in FIG. That is, in the evaluation result data 625, as a result of comparing the state data 622 with the initial state data 623 and the reference value data 624, it is determined whether or not each value included in the state data 622 is within an allowable range. Included as indicated information. It is also possible to determine whether the height and posture angle of the gimbal tongue 223 are within the reference by comparing the state data with a predetermined reference value without using the initial state data.

  As a result of comparing the state data 622 with the initial state data 623 and the reference value data 624, the evaluation data calculation unit 612 determines whether each value of the state data 622 is within an allowable range indicated by the initial state data 623 and the reference value data 624. By judging whether or not, the state of the test suspension 120 is evaluated, and whether each value is within the allowable range is judged by ○ or ×. Then, based on the determination result of each value, the evaluation result data 625 is generated by determining whether or not the test suspension 120 to be inspected can be continuously used as a comprehensive determination.

  The evaluation result data 625 obtained in this way is displayed on a display (not shown) connected to the computer 6. The operator refers to the evaluation result of the test suspension 120 displayed on the display and determines whether or not the test suspension 120 needs to be replaced.

  The test suspension 120 in which the head slider 105 is mounted, which is performed in S203, may be inspected along the same flow as in FIG. 10, using the same device as that shown in FIG. it can. Since the operation of each part is the same as the above description, the description is omitted. In a state where the head slider 105 is mounted, the inclination and height of the head slider 105 with respect to the load beam 203 surface are measured and evaluated. Thus, according to the second method, it is possible to inspect the tilt and height of the head slider 105 placed on the gimbal tongue 223 or the gimbal tongue 223 mainly with respect to the load beam 203.

  In the DET of the present embodiment, the DET is performed while confirming the state of the test suspension 120 by using the first method and the second method described above. As a result, even when DET of a plurality of head sliders 105 is performed using one test suspension 120, the state of the test suspension 120 can be maintained so that appropriate characteristics of the head slider 105 can be evaluated. It is possible to know a suitable timing for replacing the suspension 120 for use.

  Here, preferably, in a state where the head slider 105 is mounted on the gimbal tongue 223, a continuity test for inspecting the continuity between the head element portion and the connection terminal 221 is performed before DET. In the aspect described in the first method, the electrical connection level is evaluated without mounting the head slider 105 on the gimbal tongue 223. However, if a continuity test is performed, the electrical connection between the head element portion and the connection terminal 221 is performed. The level can be inspected directly and a more reliable check can be made.

  If the inspection result is a pass, the head slider 105 is removed from the test suspension 120 and the head slider 105 is mounted on the product suspension 110. FIG. 12 schematically shows a mounting method of the head slider 105. In FIG. 12, the head slider 105 is mounted on the suspension 110, not the test suspension 120. However, since the suspension 110 and the test suspension 120 have the same configuration, The same reference numerals are used for the respective parts of the test suspension. As shown in FIG. 12A, the bottom surface of the head slider 105 is fixed to the gimbal tongue 223 surface with an adhesive layer 281. Typically, these are fixed by a low elastic epoxy resin or the like.

  Further, the connection terminal 221 and the head slider terminal are connected by solder ball bonding or gold ball bonding. Specifically, as shown in FIG. 12A, a conductor ball 282 made of solder or gold is disposed between the connection terminal 221 and the head slider terminal, and laser light is irradiated to the conductor ball. The conductor ball is melted by the laser irradiation, and as shown in FIG. 12B, a conductor layer 283 that electrically and physically connects the connection terminal 221 and the head slider terminal is formed.

  If the test suspension is strong, the test suspension can be used as a part of the head gimbal assembly. Hereinafter, description will be given with reference to FIG. A suspension having a mechanism for mechanically clamping the slider and a mechanism for electrical contact is prepared (S131), and a slider is mounted on the suspension and temporarily fixed (S132), and the state is confirmed. It is possible to automate these tasks with the Slider mounter.

  If the held state is appropriate, DET is performed (S133). At this time, not only read / write characteristics but also BER (Bit Error Rate) is measured. Since BER has a correlation with SER (Sector Error Rate), adding this as a DET measurement item eliminates products that do not satisfy certain standards before assembling as a hard disk drive, thereby improving production efficiency. Can be raised.

  With respect to the process up to the confirmation of the holding state before performing DET, the method of the above embodiment may be used. Next, with respect to the combination of the slider and the suspension for which good characteristics are obtained by DET (PASS in S133), the slider is fixed and electrically connected (S134). Specifically, the connection terminal of the suspension and the terminal of the head slider are connected by solder ball bonding or gold ball bonding to form a finished product as a head gimbal assembly (S135).

  On the other hand, for a combination of a slider and a suspension that is determined to be insufficient by DET (FAIL in S133), the slider is removed from the suspension, and the slider is discarded, but the suspension is reused (S136). By automating the slider mounter, tester, and main fastening process, the HGA process including test selection can be completely automated, and the production process can be further increased.

  The above description describes the embodiment of the present invention, and the present invention is not limited to the above-described embodiment. A person skilled in the art can easily change, add, and convert each element of the above-described embodiment within the scope of the present invention. For example, as described above, it is preferable to check and evaluate the state of the test suspension 120 every time the head slider 105 mounted on the test suspension 120 is replaced. However, it can also be performed once every plural times instead of every time. Alternatively, the suspension of this embodiment and its inspection method can also be used for evaluation of the head slider with a strong magnetic field, examination of the transmission path of the suspension, and examination of mechanical vibration.

1 is a schematic plan view showing a configuration of a hard disk drive in the present embodiment. It is a flowchart which shows the manufacturing process of the head gimbal assembly in this embodiment. It is a figure which shows typically the structure of the head gimbal assembly in DET in this embodiment. It is a figure which shows typically the structure of the suspension for a test in this embodiment. It is a block diagram showing typically the composition of the suspension evaluation apparatus for a test concerning the 1st method in this embodiment. It is a flowchart which shows the evaluation process of the suspension for a test which concerns on the 1st method in this embodiment. It is a figure which shows the example of the information contained in the data produced | generated in the case of evaluation of the suspension for a test which concerns on the 1st method in this embodiment. It is a figure which shows typically the structure of the suspension for a test in this embodiment. It is a block diagram which shows typically the structure of the suspension evaluation apparatus for a test which concerns on the 2nd method in this embodiment. It is a flowchart which shows the evaluation process of the suspension for a test which concerns on the 2nd method in this embodiment. It is a figure which shows the example of the information contained in the data produced | generated in the case of evaluation of the suspension for a test which concerns on the 2nd method in this embodiment. It is a figure which shows typically the aspect of this connection of a suspension and a head slider in this embodiment. It is a flowchart which shows the manufacturing process of the head gimbal assembly which applied this embodiment. It is a figure which shows typically the structure of the head gimbal assembly in a prior art.

Explanation of symbols

1 suspension evaluation device, 2 CCD camera, 3 computer,
4 Suspension evaluation device, 5 Laser irradiation / light receiving device, 6 Computer,
31 CPU, 32 main memory, 33 non-volatile storage device,
34 interface I / O, 61 CPU, 62 main memory,
63 Nonvolatile storage device, interface I / O, 101 magnetic disk,
102 base, 103 VCM, 105 head slider,
106 Actuator, 107 Rotating shaft, 110 Suspension,
111 arm, 112 coil support, 113 flat coil,
114 upper stator magnet holding plate, 115 ramp mechanism, 116 tab,
120 suspension for testing, 151 inflow side, 152 outflow side,
200 head gimbal assembly, 201 trace, 202 gimbal,
203 Load beam, 221 connection terminal, 222 opening,
223 Gimbal tongue, 224 Spring clamp, 225 Gimbal arm,
226 opening, 227 stopper, 231 dimple, 232 reference hole,
281 Adhesive layer, 282 Conductor ball, 283 Conductor layer, 311 Image data conversion unit,
312: Coordinate data analysis unit, 313 evaluation data calculation unit, 321 actual image data,
322 coordinate data, 322 initial coordinate data, 324 status data,
325 reference value data, 326 evaluation result data, 401 head slider,
402 suspension, 403 trace, 404 gimbal,
405 load beam, 406 mount plate, 407 tab,
611 coordinate sequence data conversion unit, 612 evaluation data calculation unit, 621 coordinate sequence data,
622 state data, 623 initial state data, 624 reference value data,
625 Evaluation result data

Claims (13)

A method of manufacturing a head gimbal assembly comprising a head slider and a suspension for holding the head slider,
A flexible gimbal having a load beam, a tongue for positioning the head slider, and a spring-type clamp for pressing and holding the head slider on the tongue. Prepare a test suspension with
Measure the structural characteristics of the test suspension,
As one of the conditions that the measured structural characteristics are at a reference level, a head slider is mounted on the test suspension,
Test the head slider and test suspension assembly,
Assembling a head gimbal assembly using the tested head slider.   The method according to claim 1, wherein the height of the tongue relative to the load beam is measured as a structural characteristic of the test suspension.   The method according to claim 1, wherein a posture angle of the tongue is measured as a structural characteristic of the test suspension.   The method according to claim 1, wherein a distance between the stopper that clamps the head slider between the clamp and the clamp is measured as a structural characteristic of the test suspension.   The method of claim 4, wherein the distance between the stopper and the clamp is measured using a relationship of the clamp to a reference position and a relationship of the stopper to the reference position.   The method according to claim 1, wherein a distance between the clamp and a reference position is measured as a structural characteristic of the test suspension.   The method according to claim 1, wherein a distance between a reference position and a stopper that sandwiches the head slider with the clamp is measured as a structural characteristic of the test suspension.   The method according to claim 1, wherein a distance between a reference terminal and a connection terminal that contacts the pad of the head slider and transmits an electrical signal is measured as a structural characteristic of the test suspension. Further, the positional deviation of the head slider fixed on the tongue using the clamp with respect to the dimple supporting the tongue is measured.
The method according to claim 1, wherein the head slider is mounted on another test suspension when the deviation exceeds a reference value.   Further, the continuity between the head slider fixed on the tongue using the clamp and the probe that is in contact with the pad of the head slider is measured. The method according to claim 1, wherein the head slider is mounted on a test suspension. A method of manufacturing a head gimbal assembly comprising a head slider and a suspension for holding the head slider,
A load beam, a tongue for positioning the head slider, and a spring clamp for pressing and holding the head slider on the tongue; a flexible beam fixed on the surface of the load beam; A test suspension with a gimbal,
Fix the head slider on the tongue using the clamp,
Measure the displacement of the head slider fixed on the tongue with respect to the dimple that supports the tongue,
Using the test suspension as one of the conditions that the positional deviation is within the reference, and mounting the head slider on another test suspension when the positional deviation exceeds the reference,
Test the slider and test suspension assembly,
Assembling a head gimbal assembly using the tested slider.   The method of claim 11, wherein the misalignment is measured using a relationship between a reference position on the head slider and a reference position on the load beam.   Before mounting the head slider, the distance between the clamp and the stopper that clamps the head slider is measured, and if the distance is outside the reference, another test suspension The method according to claim 11, wherein the head slider is mounted on the head.

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