JP2007048425A - Magnetic head slider testing apparatus and magnetic head slider testing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic head slider testing apparatus in which a current output circuit of a DC magnetic field and a high frequency magnetic field can be shared, a magnetic field leaked to the periphery from a core is suppressed, and which can be miniaturized. <P>SOLUTION: A coil generating a DC magnetic field for a magnetic head is provided on a frame shape core dividing the coil into a first coil and a second coil. And distance of a gap is shortened and a head slider is held on a table having a top end portion of thin thickness, while advancing and retreating the table in the direction perpendicular to the core, the head slider is inserted into the gap from the lateral direction. Thereby, the distance of the gap is reduced to about half of the conventional one, and reduction of inductance of the first coil and the second coil is realized. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a magnetic head slider inspection apparatus and a magnetic head slider inspection method, and more particularly to a composite magnetic head inspection apparatus having an MR head (magnetoresistance effect type magnetic head), in particular, MR in the state of a single slider (chip). In the magnetic head slider inspection device that measures the electrical characteristics of the head, the DC magnetic field and the high frequency magnetic field current output circuit can be shared and the magnetic field leaking from the core or coil to the periphery can be suppressed. The present invention relates to an improvement in a magnetic head slider inspection apparatus that can reduce the size of the apparatus.
The high frequency used in this specification and the claims does not mean a frequency of 3 MHz or higher in the wireless sector, but is higher than the commercial power supply frequency of 100 Hz to 200 Hz in the power sector, Usually, it means a frequency in a frequency band of 200 Hz or higher.

2. Description of the Related Art In recent years, a magnetic head of a hard disk device is a composite magnetic head (hereinafter referred to as an MR head) in which an MR head, a GMR head, a TMR head, etc. (hereinafter referred to as an MR head) are incorporated on the reading side of a write side inductive head. ) Is used.
The recording density of hard disks is steadily improving at several tens of giga inches / inch. Moreover, the mounting of HDDs in digital home appliances is accelerating the increase. For this reason, the demand for magnetic head assemblies that are indispensable for HDDs is also increasing rapidly.
A magnetic head assembly usually comprises a head slider on which a composite head having an MR head is mounted and a suspension spring or the like that supports the head slider. The head slider is fixed to a head actuator such as a voice coil motor via the suspension spring.

The composite head in the head slider is integrally formed with the slider by a thin film process. Unlike the inductive head on the recording side, the MR head is prone to defects such as a resistance failure, an insulation failure between the shields, and an electrical characteristic failure. Therefore, an electrical characteristic inspection of a magnetic head including an MR head or the like is performed in the state of a lidar alone.
As an inspection for defective products in the head slider (slider alone) before assembling as a head assembly, an inspection apparatus that measures the reproduction characteristics of an MR head after applying a DC magnetic field from the outside to the MR head is known. (Patent Document 1).
Further, as an inspection of the assembled state as a head assembly, an AC recording magnetic field is applied to the MR head, or a DC magnetic field is applied from the outside, and the output voltage waveform is obtained from the MR head and its characteristics are inspected. Known (Patent Document 2).
JP 2000-260012 A JP-A-10-124828

The size of the head slider is at most 1 mm square or less, and four or six connection terminals to the composite head are provided on the rear side surface (trailing edge) of the head slider. . The height of the head slider is about 0.5 mm, and the magnetic head is usually provided at the trailing edge of the slider together with the connection terminals. In the inspection with the head slider (slider alone), the inspection cannot be performed unless four or six connection terminals are securely in contact with the probe.
In addition, when measuring the reproduction characteristics of the MR head with a magnetic field applied from the outside, this type of inspection apparatus must arrange the external magnetic field generator very close to the head slider. Furthermore, there are many items to be measured, such as MR head pseudo magnetic response characteristic inspection (QUASI-TEST / quasi inspection) and hysteresis characteristic inspection as a magnetic material, and one item in a short time (about 1 second). The head slider test must be completed.
An MR head is an element that changes a specific resistance in response to a magnetic field generated from data recorded on a medium. Therefore, the pseudo magnetic response characteristic inspection does not read the data actually written to the disk by the MR head, but applies a high-frequency magnetic field similar to the written data to the MR head from the outside to read the data. In this case, the read characteristic is inspected by creating a situation as if the MR head is receiving the magnetic field. This inspection needs to be repeated several hundred times under the same conditions. Moreover, it is necessary to change the magnitude and direction of the magnetic force applied to the MR head. That is, a high-frequency magnetic field that alternately swings a magnetic field from 0 to + side (for example, a magnetic field downward with respect to the head slider) and from 0 to − side (for example, a magnetic field upward with respect to the head slider) at a predetermined level. An external magnetic field generator that generates

On the other hand, in the hysteresis characteristic test, a DC magnetic field is applied from the outside, and the magnetic force (magnitude of the magnetic field) is gradually increased from 0 to the + side, gradually decreased and then returned to 0, and then the − side magnetic force is applied. Is increased and then decreased to zero. Therefore, it is necessary to generate a DC magnetic field having a large magnetic force. A separate external magnetic field generator is provided.
Each of these two external magnetic field generators requires a power source, a current output circuit, and the like. However, there is only one inspection region where the connection terminal of the head slider contacts the probe, and only one core having a gap (gap) for generating a magnetic field is provided there. For this reason, in this type of inspection apparatus, coils for generating a high-frequency magnetic field with a thin winding and for generating a DC magnetic field with a thick winding are wound around one core. As these coils move away from the inspection area on the core, the magnetic force generation efficiency decreases. For this reason, unless the inductance is increased, a magnetic force having a desired magnetic field strength cannot be generated in the inspection region (gap). As a result, the leakage magnetic field to the periphery also increases accordingly.
When a rectangular frame-shaped core is used, this type of magnetic head slider inspection apparatus has a DC magnetic field and a high-frequency magnetic field on one side of the core having a gap due to the arrangement relationship of inspection stages and inspection probes provided around the inspection region. It is difficult to provide two coils for generating For this reason, as shown in FIG. 1 of Patent Document 2, it is necessary to provide a coil on the side of the back surface facing the side having the inspection region (gap). In this case, in this type of magnetic head slider inspection apparatus, the position of the coil moves away from the gap (inspection position), so that the inductance (the number of turns) of the coil increases, and the leakage magnetic field to the periphery must be increased. . This adversely affects the inspection result, and also causes a problem that the entire apparatus becomes large.
An object of the present invention is to solve such problems of the prior art, and it is possible to share a DC magnetic field and a high frequency magnetic field current output circuit, and to suppress a magnetic field leaking from the core or coil to the periphery. It is an object of the present invention to provide a magnetic head slider inspection apparatus that can perform the above-described process.
Another object of the present invention is to provide a magnetic head slider inspection apparatus capable of reducing the size of the apparatus.
Still another object of the present invention is to provide a magnetic head slider inspection method which can share a DC magnetic field and a high frequency magnetic field current output circuit and can suppress a magnetic field leaking from the core to the periphery.

In order to achieve such an object, the configuration of the magnetic head slider inspection apparatus according to the present invention comprises a magnetic head and a plurality of connection terminals connected to the magnetic head on a side surface of the head slider in the state of the head slider. In a magnetic head slider inspection device for inspecting the characteristics of a magnetic head,
A frame-shaped core having a gap, a first coil and a second coil provided across the gap to generate a magnetic field having a predetermined strength in the gap, and a contact between the plurality of connection terminals. A probe, and a table on which the head slider is placed and which moves forward and backward with respect to the gap to insert the head slider into the gap,
The probe and the table are arranged across the gap in a direction orthogonal to the core, and the head slider is inserted into the gap by the advance of the table, and the plurality of connection terminals contact the probe. In order to generate a DC magnetic field in the gap, the first coil and the second coil are connected in series so that a predetermined drive current flows, and a high frequency magnetic field is generated in the gap. In addition, an AC driving current of 200 Hz or more is passed through only one of the first coil and the second coil.
The configuration of the magnetic head slider inspection method according to the present invention is such that the frame-shaped core provided with the first coil and the second coil across the gap is perpendicular to the gap forming direction. The probe and the table are arranged across a gap,
Placing the head slider on the table; advancing a table on which the head slider is placed; and inserting the head slider into the gap to contact the plurality of connection terminals and the probe; A DC magnetic field generating step of connecting a first coil and a second coil in series to flow a predetermined drive current to generate a DC magnetic field in the gap; and one of the first coil and the second coil A high-frequency magnetic field generation step for generating a high-frequency magnetic field in the gap by flowing an AC driving current of 200 Hz or more only to inspect the characteristics of the magnetic head.

As described above, according to the present invention, the coil that generates a DC magnetic field for the magnetic head is divided into the first coil and the second coil, and the frame-shaped core is provided. Then, the head slider is held on a table having a thin tip with the width of the gap reduced, and the table is advanced and retracted in a direction perpendicular to the core to insert the head slider into the gap from the lateral direction. As a result, the width of the gap need only be such that the head slider can be sufficiently inserted, and the gap width (gap) can be reduced to about half of the conventional width. For example, the gap size, which has conventionally been about 12 mm, can be reduced to about 6 mm. As a result, the inductances of the first and second coils can be reduced.
As a result, the inductance of the entire coil can be reduced, the number of turns to the core is reduced, and the entire coil is divided into two parts, the first coil and the second coil, so that the inductance of one coil is half of the whole. A coil having a small inductance can be assigned to a coil for generating a high-frequency magnetic field. Since the inductance of each of the two divided coils has a small inductance, it does not have to be increased accordingly. When a DC magnetic field is generated, the first coil and the second coil are connected in series, so that a large inductance can be obtained.
When the core has a rectangular shape, the present invention provides the first coil on one side with a gap and the second coil on the other side instead of the one side with the first coil. Can do. In the latter case, the number of turns of the second coil can be increased and the number of turns of the first coil can be reduced. As a result, the first coil with a small number of turns is more likely to generate a high-frequency magnetic field, and its outer shape is also suppressed. As a result, the first coil can be provided near the gap, and the efficiency of magnetic field generation is improved.
If the coil for generating a DC magnetic field is divided into two in this way, there is no need to provide two coils for generating a high-frequency magnetic field with a thin winding and a DC magnetic field with a thick winding.
As a result, the present invention can share a DC magnetic field and a high frequency magnetic field current output circuit, and can suppress a magnetic field leaking from the core or coil to the periphery in the magnetic head slider inspection apparatus. Thereby, size reduction of a magnetic head slider test | inspection apparatus can be achieved.

FIG. 1 is an overall configuration diagram of a magnetic head slider inspection apparatus to which the present invention is applied, FIG. 2 is a block diagram of a relationship between a coil drive circuit for generating an external magnetic field and an external magnetic field generator, and FIG. FIG. 4 is an explanatory diagram of the relationship between the suction state of the suction pickup and the slider and the probe, and FIG. 5 is an explanatory diagram of the side surface abutting positioning unit. 6 is an explanatory view of the relationship between the core and the coil of another specific example of the external magnetic field generator, and FIG. 7 is an explanatory view of the slider array block.
10 is a magnetic head slider inspection device, 1 is its inspection stage, 2 is a handling robot, 3 is an inspection probe unit, 4 is an external magnetic field generator, 5 is a pallet (see FIG. 3), and 6 is a pallet moving stage. , 7 is a measuring section, 8 is a measuring device, and 9 is a head slider (hereinafter referred to as a slider; see FIGS. 3 and 4). The pallet 5 stores the sliders 9 in the storage holes 5a arranged in a large number of vertical and horizontal directions.
The inspection stage 1 is an XY moving stage, and includes a Y stage 12 provided on the X stage 11, a side surface positioning unit 13 (see FIG. 5) provided on the Y stage 12, and a Y stage 12. It consists of a back contact positioning part 14 (see FIG. 4) provided adjacently.

The side surface abutting positioning part 13 and the back surface abutting positioning part 14 have contact side surfaces on which the side surface of the slider 9 and the front edge of the slider 9 (the back surface with respect to the side surface with the connection terminal) are respectively abutted. These abutting side surfaces are side surfaces orthogonal to each other in parallel with the X axis and the Y axis.
As shown in FIG. 5, the side surface abutting positioning portion 13 is provided with protrusions formed at corners of the flat plate block 131. This has an abutting side surface 135, and two pins 133 and 134 are provided on the abutting side surface 135, and the side surfaces of these pins 133 and 134 become the abutting side surfaces with respect to the side surface of the slider 9. 5 is fixed to the base 15 of the magnetic head slider inspection apparatus 10 via a bracket 132, as shown in FIG.
As shown in FIG. 4 and FIG. 5, the back bump positioning portion 14 is at the mounting position of the slider 9 provided as a stepped portion 14 a on the Y stage 12. The back surface 14b of the stepped portion 14a (see the dotted line portion in FIGS. 5 and 4) is a contact side surface with respect to the front edge of the slider 9.
By the way, since the linear movement mechanism of the X stage 11 and the Y stage 12 is general, it is not shown in particular.
As shown in FIG. 2, the measuring device 8 includes a control unit 81 and a coil drive circuit 82. The control unit 81 includes a microprocessor (MPU) 81a, a memory 81b, and a control computer incorporating a control program and the like installed in the memory.

The coil driving circuit 82 includes a coil connection switching circuit 83, a high-frequency driving signal generation circuit 84, a variable DC magnetic field driving signal generation circuit 85, an input signal switching circuit 86, and a power amplification circuit 87 serving as a current output circuit.
The coil connection switching circuit 83 performs connection switching for connecting the terminal A to either the terminal B or the terminal C according to the control signal S from the control unit 81.
The terminal A of the coil connection switching circuit 83 is connected to the other terminal of the first coil 4c, the terminal B is connected to the output terminal 87b as described above, and the terminal C is the other terminal of the second coil 4d. Connected to the terminal.
Thereby, the case where the first coil 4c is connected in series with the second coil 4d and connected to the output of the power amplifier circuit 87 and the case where it is directly connected to the output of the power amplifier circuit 87 are selected. The
The input signal switching circuit 86 selects one of the high-frequency drive signal generation circuit 84 and the variable DC magnetic field drive signal generation circuit 85 and outputs it to the input terminal 87 a of the power amplification circuit 87. In the power amplifier circuit 87, one output terminal 87b of the pair of output terminals is connected to one terminal of the first coil 4c, and the other output terminal 87c is connected to the terminal B of the coil connection switching circuit 83 and the second coil. 4d is connected to one terminal.
The high frequency drive signal generation circuit 84 and the variable DC magnetic field drive signal generation circuit 85 are each controlled by the control unit 81 to generate drive signals for current driving the coils.

Returning to FIG. 1, the gap 4b forms a rectangular block space corresponding to the cross-sectional shape of the frame core 4a. The inspection probe unit 3 and the Y stage 12 are arranged via a gap 4b so as to correspond to the space in the frame width direction of the frame core 4a in the X direction (lateral direction) perpendicular to one side 41 standing along the Z direction. Are provided opposite to each other. The Y stage 12 moves in the X direction by driving the X stage 11, and advances and retreats with respect to the gap 4b.
Since the frame core 4a has a rectangular space inside, the inspection probe unit 3 and the Y stage 12 are arranged so as to correspond to the gap 4b in the Y direction (lateral direction) orthogonal to the width direction of the frame core 4a. May be.
The inspection probe unit 3 is fixed to the frame 16 of the apparatus and is connected to the measuring apparatus 8, and the tip of the probe 3a is not visible behind the frame core 4a in FIG. 1, but as shown in FIG. In addition, the measuring unit 7 protrudes into the gap 4b from the opposite side to the gap 4b so as to face the Y stage 12. As shown in FIG. 2, the measurement signal obtained from the inspection probe unit 3 is A / D converted via the amplifiers 80 a and A / D 80 b and input to the measurement device 8.
As shown in FIGS. 1 and 2, the external magnetic field generator 4 is an electromagnetic magnet, and includes a frame core 4a having a gap (gap) 4b at the position of the measurement unit 7 and a first coil 4c wound around the frame core 4a. The second coil 4d (see FIG. 2) is fixed to the base 15 of the magnetic head slider inspection apparatus 10 via a bracket 17 (see FIG. 2). In the external magnetic field generator 4, the coils 4 c and 4 d are driven by receiving power supply from the coil drive circuit 82.
As shown in FIG. 4, the distal end portion (tip end of the needle) of the probe 3a of the inspection probe unit 3 reaches the end of the narrow gap 4b, and a part thereof enters here. The Y table 12 opposite to this has a front end portion 12a having a thickness D smaller than the gap 4b. Therefore, when the slider 9 is inspected, the Y table 12 moves forward in the direction of the gap 4b and the leading end 12a of the Y table 12 is inserted into the gap 4b, so that the slider 9 is substantially vertically above and below the space of the gap 4b. The probe 3a contacts the inside of the gap 4b. In this state, a magnetic field is applied to the slider 9 for inspection.
The tip portion 12a of the portion inserted into the gap 4b is formed of a non-magnetic conductive resin, and the thickness D of the tip portion 12a is 2.8 mm to 3.8 mm. By forming the tip portion 12a from a non-magnetic conductive resin, the measurement of the slider 9 to which a magnetic field is applied is not affected, and the slider 9 is not required to be scooped.

The first coil 4c is obtained by winding a copper wire having a wire diameter of 0.3 to 0.6 mmφ around the core for about 70 to 80 turns on the upper side of the gap 4b of the side 41 where the gap 4b of the frame core 4a is provided. The inductance is about 0.8 mH to 1 mH. On the other hand, the second coil 4d has a copper wire having the same wire diameter of 0.3 to 0.6 mmφ as the first coil 4c on the lower side 42 adjacent to the side having the gap 4b of the frame core 4a. It is wound about 100 to 120 turns, and its inductance is about 1 mH to 1.5 mH.
The outer shape of the frame core 4a is in the range of 80 mm × 120 mm to 90 mm × 130 mm, the frame width is about 20 mm to 30 mm, the thickness is about 3 mm to 6 mm, and the gap 4b is about 3 mm to 7 mm. 9 is a width that can be inserted by advancing and retracting the Y table 12.
Note that the position of the first coil 4c on the side 41 is disposed at a position that does not interfere with the movement of the Y table 12 in the direction of the gap 4b.

In FIG. 2, when the coil connection switching circuit 83 connects the terminal A and the terminal B in accordance with the control signal S of the control unit 81, it becomes a high-frequency magnetic field generation side, and the power amplifier circuit 87 is connected only to the first coil 4c. Connected and not connected to the second coil 4d. On the other hand, when the coil connection switching circuit 83 connects the terminal A and the terminal C in response to the control signal S, the first coil 4c and the second coil 4d are connected in series on the DC magnetic field generation side. This series circuit is connected to the power amplifier circuit 87.
The control signal S is also input to the input signal switching circuit 86. When the terminal A and the terminal B of the coil connection switching circuit 83 are connected, the input signal switching circuit 86 responds to the control signal S with a high frequency drive signal generation circuit. The output signal 84 is selected as an input signal and input to the power amplifier circuit 87. Therefore, the power amplifier circuit 87 supplies, for example, a high-frequency drive current (AC drive current of 200 Hz or more) of about 10 kHz to the coil. At this time, the control unit 81 controls the high-frequency drive signal generation circuit 84 to control the magnitude of the drive current, thereby adjusting the magnitude of the magnetic force applied to the MR head, and a magnetic field exceeding 200 Oe is generated in the gap 4b.
The frequency of the high frequency magnetic field is selected from a range of about 5 kHz to 20 kHz.
On the other hand, when the terminals A and C of the coil connection switching circuit 83 are connected, the input signal switching circuit 86 selects the output signal of the variable DC magnetic field drive signal generation circuit 85 as an input signal according to the control signal S. Input to the power amplifier circuit 87. Therefore, the power amplifier circuit 87 supplies a DC drive current to the coil. At this time, the control unit 81 controls the variable DC magnetic field drive signal generation circuit 85 to control the magnitude and direction of the drive current. Thereby, the magnitude and direction of the magnetic force applied to the MR head are controlled.

The inspection probe unit 3 shown in FIG. 1 is fixed to the frame 16 of the apparatus, and is connected to the control unit 81 via an amplifier 80a and an A / D 80b. At the time of the inspection in which the magnetic field as described above is applied to the slider 9, since the tip portion (see FIG. 4) of the probe 3a is in contact with the slider 9 in the measuring section 7, a measurement signal is obtained from the inspection probe unit 3, Is A / D converted by the A / D 80 b and input to the control unit 81.
When performing a pseudo magnetic response characteristic test (QUASI-TEST / quaddy test), the control unit 81 generates a control signal S and switches the coil connection switching circuit 83 to the high frequency magnetic field side. Therefore, the power amplifier circuit 87 drives the first coil 4c with a high-frequency current.
At this time, the high-frequency drive signal generation circuit 84 is controlled by the control unit 81 to generate a sine wave having a predetermined amplitude at about 10 kHz, for example, corresponding to the + side write signal, and then generate a sine wave. The amplitude is set to “0” for a fixed period, and thereafter, a sine wave is generated for a fixed period corresponding to the negative side write signal, and signals in which the amplitude of the sine wave is “0” for a fixed period are sequentially generated. With this order as one time, the control unit 81 repeats the same many times and causes the high frequency drive signal generation circuit 84 to generate a drive signal. The control unit 81 causes the high-frequency drive signal generation circuit 84 to repeat this about 500 times, and at the same time, the control unit 81 time-sequentially reads the MR head read signal to the internal memory via the amplifiers 80a and A / D 80b. To store as measurement data.

On the other hand, when the hysteresis characteristic inspection as a magnetic material is performed, the control unit 81 generates a control signal S and switches the coil connection switching circuit 83 to the DC magnetic field side. The power amplifier circuit 87 drives a series circuit of the first coil 4c and the second coil 4d with a DC current.
The DC drive current here is a step current converted into a staircase shape or a pulse waveform current whose amplitude changes sequentially. The rising portion of the current of the pulse waveform is preferably a waveform that rises with a sine wave and becomes DC in the rising state.
At this time, the variable DC magnetic field drive signal generation circuit 85 first generates an output signal that generates a magnetic field (+ side magnetic field) that changes downward with respect to the gap 4d under the control of the control unit 81. Due to the DC output current of the power amplifier circuit 87, the magnetic force in the gap 4b gradually increases from “0” until it reaches a predetermined value, and when it reaches the predetermined value, it decreases toward “0”. Go. Next, the variable DC magnetic field drive signal generation circuit 85 generates an output signal that generates a magnetic field (-side magnetic field) that changes in a reverse direction in which the magnetic force of the gap 4b is upward with respect to the gap 4d. The magnetic force in the gap 4b gradually increases from “0” due to the DC output current of the power amplifier circuit 87, and increases in the reverse direction until reaching a predetermined value on the negative side. It will decrease in the opposite direction. At the same time, the read signal of the MR head at this time is stored as measurement data in time series in the internal memory by the control unit 81 via the A / D 80b.

Next, a slider handling process for positioning the slider 9 on the Y table in the XYZ will be described. In this positioning, the Y table 12 is integral with the X table 11 without moving in the Y direction.
Returning to FIG. 1, the handling robot 2 is a YZ movement stage, and the Z stage 22 moves up and down by the Y stage 21 supporting the side surface of the Z stage 22. The Y stage 21 is connected to a Y direction moving mechanism (not shown) via an arm 21a. The Z stage 22 is provided with a suction pickup (a suction collet with a conical tip, see FIG. 4) 23 attached to the lower surface.
The suction pickup 23 sucks and holds the slider 9 from the pallet 5 and moves in the YZ direction so that the slider 9 moves back and forth in the Y direction on the line parallel to the Y axis and moves the slider 9 onto the Y table 12 of the inspection stage 1. Conversely, the inspected slider 9 is stored from the Y table 12 of the inspection stage 1 to the original position of the pallet 5.

As shown in FIG. 4, the diameter of the tip of the suction pickup 23 is smaller than the rectangular outer peripheral shape of the slider 9.
In FIG. 1, the pallet moving stage 6 is an X direction moving stage on which the pallet 5 is mounted. The pallet moving stage 6 is moved to the X direction and inspected to a position below the pickup position in the Y direction of the suction pickup 23 of the handling robot 2. The target slider 9 (the position of the storage hole 5a, see FIG. 3) is moved. The position of the pallet 5 is controlled by the measuring device 8 through the pallet moving stage 6.
As shown in FIG. 3, the slider 9 is sucked by the suction pickup 23 in the storage hole 5 a of the pallet 5. The storage hole 5 a is a rectangular hole that is slightly larger than the slider 9. Therefore, as the suction position offset process, first, in the pallet 5, the two orthogonal side surfaces in the XY direction of the slider 9 are sequentially abutted against the two orthogonal side surfaces in the XY direction of the storage hole 5a, and the suction position of the slider 9 is corrected. Is done. As a result, the offset positioning of the suction position of the slider 9 is performed. This is because the X side surface 9a and Y side surface 9b (see FIG. 4) of the slider 9 are abutted later to move the suction position of the slider 9, so that the suction position is moved in advance in the opposite direction to that direction, This is a process of giving an offset to the XY positioning position of the slider 9. In other words, this offset is the normal position coordinates (Xs, Ys) of the suction center of the suction pickup 23 (corresponding to the center O of the slider 9; see FIG. 4) in the side surface contact positioning unit 13 and the back surface contact positioning unit 14. ) (See FIG. 4), the suction position is shifted in advance to (Xs + α, Ys + β). However, α and β shown in FIG. 3 are arbitrary offset amounts.

Thereafter, the Z stage 22 is driven and the slider 9 is picked up by the suction pickup 23. Subsequently, when the Y stage 21 is driven, the slider 9 moves in the Y direction together with the suction pickup 23, and the side surface (X side surface) 9 a (see FIG. 4) along the X direction of the slider 9 contacts the side surface abutting positioning unit 13. The suction position in the Y direction is adjusted by abutting against the side surface (see FIG. 5) and placed on the stepped portion 14a of the Y stage 12 (see the front portion of the stage 12 in the dotted line portion in FIGS. 5 and 4). Subsequently, the X stage 11 moves forward, and the side surface (the front edge of the slider 9) 9b (see FIG. 4) along the Y direction of the slider 9 is on the back surface 14b (contacting side surface) of the stepped portion 14a of the back contact positioning portion 14. It is hit. Thereby, the position of the X direction is adjusted by pushing the slider 9 out. Thereafter, the slider 9 is adsorbed by negative pressure through an adsorption hole (not visible under the slider 9 in FIG. 5) provided in the bottom surface 14c (see FIG. 5) of the step 14a and fixed to the step 14a. As a result, the slider 9 is positioned in the Z direction.
Next, the movement of the X stage 11 moves the Y stage 12 to the gap 4b side, the tip 12a of the Y stage 12 is inserted into the gap 4b, and the four connection terminals 9d of the slider 9 to the inspection probe unit 3 side. The side surface (see the rear edge of the slider) with the (see FIG. 4) is pushed out. Therefore, the four connection terminals provided on the terminal side surface 9c (see FIG. 4) of the slider 9 come into contact with the probe 3a of the inspection probe unit 3, and then the inspection is started.
Thus, the bottom surface 14c of the stepped portion 14a is a positioning surface in the Z direction with respect to the slider 9, that is, the height direction with respect to the surface of the base 15. The height of the gap 4b is set to a position corresponding to this positioning position in the Z direction. Therefore, the tip 12a can be easily inserted into the gap 4b by reducing the thickness of the tip 12a of the Y stage 12.

In the abutting of the side surface abutting positioning unit 13 and the back surface abutting positioning unit 14, as shown in FIG. 4, the coordinates of the suction center of the suction pickup 23 with respect to the slider 9 (corresponding to the center O of the slider 9) are (Xs, Ys). This is a normal suction position of the slider 9, and the slider 9 is positioned in this state with high accuracy in a short time and is fixed in the position of the suction hole of the Y stage 12 of the inspection stage 1 as the inspection position. . This completes the positioning in the height direction (Z direction), and the four terminals on the terminal surface 9c correctly contact the probe 3a of the inspection probe unit 3.
The control unit 81 brings the four connection terminals 9d into contact with the probe 3a of the inspection probe unit 3, and then generates a predetermined control signal S and drives the high-frequency drive signal generation circuit 84 to perform a pseudo magnetic response characteristic inspection (QUASII). -TEST / Quady test) is started, and after that, another predetermined control signal S is generated and the above-described hysteresis characteristic test is performed, and the measurement data collected in the internal memory 81b is stored respectively. Then, the quality of the slider 9 (MR head) is determined based on the measurement data of the MR head read signal stored in the internal memory 81b.

FIG. 6 is an explanatory diagram of the relationship between the core and the coil of another specific example of the external magnetic field generator.
In the external magnetic field generator 40, the first coil 4c and the second coil 4d are provided above and below the side 41 of the rectangular frame-shaped core 4a with the gap 4b interposed therebetween. The second coil 4d in FIG. 1 is arranged below the gap 4b from the side 42 to the side 41.
The distance D between the first coil 4c and the second coil 4d is 15 mm to 20 mm, and the number of turns of the first coil 4c and the second coil 4d is equally 90 to 100 turns. The coil winding thickness with respect to the frame core 4a is about 6 mm.
Since the thickness of the tip portion 12a of the Y table 12 is 2.8 mm to 3.8 mm, these coils are not in the way when the tip portion 12a of the Y stage 12 moves forward and is inserted into the gap 4b. Absent.
Since the connecting lead wires between the first coil 4c and the second coil 4d are obstructive, the lead wires 43a and 43b and the lead wires 44a and 44b are arranged along the guide channel case and face the side 41. Pull out to the back side. The lead wires 43b and 44b are connected by a connection terminal N outside the frame core 4a.

Thus, the first coil 4c and the second coil 4d are connected in series at the connection terminal N in advance. In the case of the external magnetic field generator 40, since the number of turns of the coil is the same, either one of the first coil 4c and the second coil 4d can be selectively driven to generate a high-frequency magnetic field. it can. Here, in place of the connection switching circuit 83 in FIG. 1, the first coil 4c is selected from the first coil 4c and the second coil 4d connected in series by the ON / OFF of the switch circuit 88 to select the power amplifying circuit. 87 shows an example of connection.
The switch circuit 88 is provided between the connection terminal N that connects the first coil 4 c and the second coil 4 d and the output terminal 87 c of the power amplifier circuit 87. This is turned ON / OFF by the control signal S of the control unit 81. When the switch circuit 88 is OFF, a DC drive current is supplied from the power amplifier circuit 87 to the first coil 4c and the second coil 4d that are connected in series, and a DC magnetic field is generated in the gap 4b. On the other hand, when the switch circuit 88 is ON, a high frequency current (AC drive current of 200 Hz or more) is passed from the power amplifier circuit 87 to the first coil 4c, and a high frequency magnetic field is generated in the gap 4b.
If the switch circuit 88 is provided between the connection terminal N and the output terminal 87b of the power amplifier circuit 87, the second coil 4d is selected instead of the first coil 4c.

Thus, in the above-described embodiment, the case where the inspection is performed in the state of the slider alone is described. However, the present invention can be applied to a head slider before being cut out individually as a slider alone.
Reference numeral 90 shown in FIG. 7 denotes a slider array block called an elongated row bar (Row Bar). This is cut out from the wafer with about 40 to 60 sliders formed in a line in the row direction of the wafer.
In such inspection of the slider array block, the frame width of the frame core 4a in the embodiment shown in FIGS. 2 and 6 is larger than the length of the slider array block in the longitudinal direction, as indicated by the dotted line 41. Accordingly, the rectangular space inside the frame core 4a becomes smaller. The step portion 14a on the Y stage 12 is long and has a large width along the frame width direction of the space 4b. The same applies to the width of the probe 3a. Other relationships are substantially the same as in the case of FIG.
Therefore, the head slider in this specification and claims includes a slider array block before such individual sliders are cut out as a single unit.

As described above, the inspection stage 1 of the embodiment is an XY moving stage, but since the present invention does not require fine adjustment in the Y direction on the Y table, the Y table of the XY moving stage is The table may be integrated with the X table, not individually.
In the embodiment, the frame core 4a of the external magnetic field generator 4 has a rectangular shape. However, the present invention is not limited to this rectangular shape. As shown in FIG. When the coil is arranged, the core may be in a loop shape having a gap.
Further, in the embodiment, an example of inspection for the slider of the MR head composite head is given, but the present invention is of course not limited to the MR head composite head.

FIG. 1 is an overall configuration diagram of a magnetic head slider inspection apparatus to which the present invention is applied. FIG. 2 is a block diagram showing the relationship between the coil drive circuit for generating an external magnetic field and the external magnetic field generator. FIG. 3 is an explanatory diagram of the relationship between the head slider stored in the pallet and the suction pickup. FIG. 4 is an explanatory diagram of the relationship between the pickup state of the pickup and the slider and the probe. FIG. 5 is an explanatory diagram of the side surface abutting positioning portion. FIG. 6 is an explanatory diagram of the relationship between the core and the coil of another specific example of the external magnetic field generator. FIG. 7 is an explanatory diagram of the slider array block.

Explanation of symbols

1 ... Inspection stage, 2 ... Handling robot,
3 ... Inspection probe unit, 3a ... Probe,
4, 40 ... External magnetic field generator,
5 ... pallet, 6 ... pallet moving stage,
7 ... measuring unit, 8 ... measuring device, 9 ... slider (head slider),
10 ... Magnetic head slider inspection device,
11 ... X stage, 12, 21 ... Y stage,
13 ... Side bump positioning part, 14 ... Back bump positioning part,
22 ... Z stage, 23 ... Suction pickup (Suction collet),
81 ... control unit, 82 ... coil drive circuit,
83 ... Coil connection switching circuit, 84 ... High frequency drive signal generation circuit,
85: Variable DC magnetic field drive signal generation circuit, 86: Input signal switching circuit,
87: A power amplifier circuit.

Claims (15)

In a magnetic head slider inspection apparatus for inspecting characteristics of the magnetic head of the head slider in a state of a head slider having a magnetic head and a plurality of connection terminals connected to the magnetic head on a side surface,
A frame-shaped core having a gap;
First and second coils provided across the gap to generate a magnetic field of a predetermined strength in the gap;
A probe provided to contact the plurality of connection terminals;
A table on which the head slider is placed and which moves forward and backward with respect to the gap to insert the head slider into the gap;
The probe and the table are arranged across the gap in a direction perpendicular to the core;
The head slider is inserted into the gap by the advance of the table, and the plurality of connection terminals are in contact with the probe,
In order to generate a DC magnetic field in the gap, the first coil and the second coil are connected in series to pass a predetermined drive current, and in order to generate a high-frequency magnetic field in the gap, the first coil A magnetic head slider inspection apparatus in which an AC drive current of 200 Hz or more is supplied to only one of the coil and the second coil.   The core has a rectangular shape with the gap on one side, the first coil is provided on the one side, and the second coil is on either the one side or the remaining side. The magnetic head slider inspection apparatus according to claim 1, wherein the magnetic head slider inspection apparatus is provided.   The magnetic head includes an MR head, and the probe is disposed in a state where a tip portion of the probe is located at an end of the gap or enters the inside of the gap, and the table moves the head slider to the tip of the table. The magnetic head slider inspection device according to claim 2, wherein the magnetic head slider inspection device is held in a portion.   The tip portion has a step portion, and the head slider is placed on the step portion, and the thickness of the tip portion is smaller than the gap interval, and the tip portion is in the gap when the table advances. 4. The magnetic head slider inspection apparatus according to claim 3, wherein   The head slider is adsorbed and held in the stepped portion, and the bottom surface of the stepped portion is a positioning surface of the head slider in the height direction with respect to the base surface, and from the base surface of the gap The magnetic head slider inspection apparatus according to claim 4, wherein the height of the magnetic head slider is set corresponding to the positioning surface.   The gap is in the range of 3 mm to 7 mm, the height direction is the Z direction in this apparatus, and the head slider is positioned in the X direction and the Y direction so that the step portion The second coil has a larger number of turns than the first coil, is disposed on any of the remaining sides, and the AC driving current is passed through the first coil. 5. The magnetic head slider inspection device according to 5.     The gap is in the range of 3 mm to 7 mm, the height direction is the Z direction in this apparatus, and the head slider is positioned in the X direction and the Y direction so that the step portion 6. The magnetic head slider inspection apparatus according to claim 5, wherein the first coil and the second coil are disposed on the one side with the gap interposed therebetween.   Furthermore, a DC magnetic field drive signal generation circuit for generating a first drive signal for generating the DC magnetic field, a high frequency drive signal generation circuit for generating a second drive signal for generating the high frequency magnetic field, and power An output circuit; and a switching circuit, wherein the current output circuit selectively receives one of the first drive signal and the second drive signal and receives the first drive signal. Generating the predetermined drive current, generating the AC drive current when receiving the second drive signal, and passing the predetermined drive current, the switching circuit includes the first coil and the 6. The magnetic head slider inspection apparatus according to claim 5, wherein a second coil is connected in series, and one of the first coil and the second coil is selected when the AC drive current is supplied.   The switching circuit has first, second, and third terminals, one of the pair of output terminals of the current output circuit is connected to one end of the first coil, The other end is connected to the first terminal, the remaining output terminal of the current output circuit is connected to one end of the second coil and the second terminal, and the other end of the second coil is the first terminal. 9. The magnetic head slider inspecting apparatus according to claim 8, wherein the switching circuit is connected to the first terminal and connected to either the second terminal or the third terminal.   The switching circuit is a switch circuit, and the first coil and the second coil are connected in series, and one of the pair of output terminals of the current output circuit is the series circuit. The other output terminal of the current output circuit is connected to the other end of the series-connected coil, and the first coil and the second coil are connected via the switch circuit. The magnetic head slider inspection apparatus according to claim 8, wherein the magnetic head slider inspection apparatus is connected to a connection point of coils connected in series.   The frequency of the AC drive current is a predetermined frequency in the range of 5 kHz to 20 kHz, and the high-frequency magnetic field is applied to the MR head in the gap to inspect the pseudo magnetic response characteristics of the MR head. The DC magnetic field drive signal generation circuit can vary the predetermined drive current value, and the DC magnetic field is applied to the MR head in the gap to perform a hysteresis test of the MR head. The magnetic head slider inspection apparatus according to claim 3.   3. The magnetic head slider inspection apparatus according to claim 2, wherein the head slider is a slider array block in which a large number of sliders are arrayed in a line. In a magnetic head slider inspection method for inspecting characteristics of the magnetic head of the head slider in a state of a head slider having a magnetic head and a plurality of connection terminals connected to the magnetic head on a side surface,
The probe and the table are arranged with the gap interposed in a direction perpendicular to the gap forming direction with respect to the frame-shaped core provided with the first coil and the second coil with the gap interposed therebetween. Have been
Placing the head slider on the table;
Advancing a table on which the head slider is placed and inserting the head slider into the gap to contact the plurality of connection terminals and the probe;
A DC magnetic field generating step in which a first coil and a second coil are connected in series to pass a predetermined drive current to generate a DC magnetic field in the gap;
A magnetic head slider for inspecting characteristics of the magnetic head, comprising: a high-frequency magnetic field generating step for generating a high-frequency magnetic field in the gap by supplying an AC drive current of 200 Hz or more to only one of the first coil or the second coil Inspection method.   The magnetic head includes an MR head, and the probe is disposed in a state where a tip portion of the probe is located at an end of the gap or enters the inside of the gap, and the table moves the head slider to the tip of the table. The magnetic head slider inspection method according to claim 13, wherein the magnetic head slider is held in a portion.   15. The magnetic head slider inspection apparatus according to claim 14, wherein the head slider is a slider array block in which a large number of sliders are arrayed in a line.

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