JP2963390B2 - Magnetic resistance measuring device for magnet resistive element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the magnetic sensitivity of a magnetic resistive element (MR element).

[0002]

2. Description of the Related Art A magnet resistive element (hereinafter referred to as "M")
R element ". ) Is an element whose electric resistance changes when a magnetic field is transmitted through the element, and is used in a detection unit of a hard disk which is a storage medium of a computer in recent years.

[0003] Originally, an MR element is required to exhibit a characteristic in which electric resistance changes with respect to the transmission of a magnetic field. Since the efficiency of forming a non-defective product is low, it is important to inspect the magneto-sensitive characteristics in the wafer state, which is a production process, to find a defective element, and to exclude the defective element.

In a conventional magneto-sensitive measuring device for an MR element,
As shown in FIG. 1A, a wafer 1 of an MR element is mounted on an XYZ stage 2 (a stage that can move in a three-dimensional direction). The magnetic field generating coils 3 are arranged on both sides of the wafer 1 of the MR element so that the magnetic poles 31 of opposite polarities face each other on both upper and lower sides.

[0005] As a measuring method in such an apparatus, an XYZ stage 2 on which an MR wafer 1 is placed is once lowered downward (moved in the Z direction downward), and then moved laterally (in the XY plane direction). Move), further raise (move upward in the Z-axis direction), contact the probe needle with the MR element 1, conduct current through the magnetic field generating coil 3, and generate a magnetic field for inspection. .

However, when a plane direction orthogonal to the direction between the pair of magnetic field generating coils is used as a reference, the projection lines of the pair of magnetic fields with respect to the pair of probes 4 are generally formed as shown in FIG. Since they are arranged so as not to intersect, when the magnetic field is changed at the time of measurement (when the value of current conducted to the pair of coils is changed), the pair of probes 4 and the MR element wafer 1 are inevitable. And the magnetic flux passing through the closed circuit formed by the measuring instrument changes, and the change in the magnetic flux generates an induced voltage in the closed circuit, the induced voltage becomes a noise voltage in the measurement, and an error with respect to the measured value. Cause.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to a magnetic resistive element wafer according to the prior art described above, wherein the measurement error caused by the induced electromotive force that is necessarily generated is reduced or possibly eliminated. It is an object of the present invention to provide a magnetic property measuring device.

[0008]

Means for Solving the Problems In order to solve the above problems, the constitution of the present invention is as follows: (1). In an apparatus for mounting a magnet resistive element wafer on an XYZ stage and measuring the magnetic susceptibility of the magnet resistive element wafer by a magnetic field generated by a pair of magnetic field generating coils , a direction connecting the pair of magnetic field generating coils projection line of a pair of probes against the direction of the plane orthogonal, by placing the probe so that the crossed state, measuring the magneto-sensitive magnet resistive element device, (2). In a device for mounting a magnet resistive element wafer on an XYZ stage and measuring the magnetic susceptibility of the magnet resistive element wafer by a magnetic field generated by a pair of magnetic field generating coils, a direction connecting the pair of magnetic field generating coils the projection line of the pair of probes against a plane orthogonal, arranged to be in a state of being superimposed
By, measurement-sensitive magnetic properties of the magnet resistive element
Device that consists of.

[0009]

According to the first configuration, FIG.
As shown in (b) and (c), since the projection lines of the pair of probes 4 intersect with a plane orthogonal to the direction between the pair of magnetic field generating coils 3, the projection lines below the intersection of the projection lines. The direction of the induced voltage generated by the change in the magnetic flux due to the magnetic field and the direction of the induced voltage above the intersecting position are opposite to each other, whereby the induced voltage is canceled. In FIG. 2, FIG.
As will be described later with reference to (a) and (b), the pair of magnetic field generating coils 3 is arranged at a position above and close to the MR element wafer 1.

Although the projection lines on the plane of the pair of probes 4 intersect, it does not mean that the pair of probes 4 are in contact with each other and intersect with each other. Since the change in resistance of the MR element wafer 1 cannot be measured, a configuration in which the projection lines intersect and the probes 4 do not contact each other will be described later in an embodiment.

In the case of the configuration (2), FIG.
As shown in (a), (b), and (c), since the pair of probes 4 are arranged so that the projection lines on the plane overlap, the pair of probes 4, the MR element wafer 1, and the measuring device The closed circuit does not intersect with the magnetic flux generated between the pair of coils 3, and therefore does not basically generate an induced voltage even if the magnetic flux changes with a change in the magnetic field.

Incidentally, the applicants have disclosed a pair of magnetic field generating coils 3.
Is arranged at a close position above the MR element wafer 1 as shown in FIGS. 4A and 4B instead of the arrangement as shown in FIGS. 1A and 1B. (A) and (b) have been filed separately from the present application.
The arrangement of the pair of magnetic field generating coils 3 corresponds to this, however, in the case of the configuration 2, the pair of probes 4 is inclined in the direction of the pair of magnetic field generating coils 3, so that In the case of the arrangements shown in FIGS. 4A and 4B, it is necessary to sufficiently consider the inclination direction of the probe so that the probe does not contact the four magnetic field generating coils 3.

[0013]

Embodiment 1 Embodiment 1 shows a typical example of the configuration (1). As shown in FIGS. 5 (a), 5 (b) and 5 (c), a pair of linear probes 4 In addition to being simply inclined in the plane direction, they are inclined in directions opposite to each other in the direction between the pair of magnetic field generating coils 3, and the projection lines with respect to the plane direction are arranged so as to intersect.

With such an arrangement, the pair of probes 4 can exhibit the operation based on the configuration (1) without being in contact with each other.

[0015]

Embodiment 2 Embodiment 2 shows another example of the configuration of (1) or (2). As shown in FIGS. 6 (a), (b) and (c), a pair of A curved probe 4 that does not contact is employed, and the curvature prevents the pair of probes 4 from contacting each other.

In the case of the second embodiment, the projected lines of the pair of probes 4 with respect to the plane are as shown in FIG.
It has a substantially figure-eight shape.

Also in the second embodiment, the operation based on the configuration (1) can be achieved without the probes 4 being in contact with each other.

The configuration of the second embodiment is suitably employed when a pair of magnetic field generating coils 3 are provided close to each other on the upper part of the MR element wafer 1 as shown in FIGS. 4 (a) and 4 (b). Is done.

[0019]

Embodiment 3 Embodiment 3 shows a typical example of the configuration (2). As shown in FIGS. 7 (a), 7 (b) and 7 (c), a pair of probes 4 At the same angle.

Therefore, the closed circuit formed by the pair of probes 4, the MR element wafer 1, and the measuring device does not intersect with the magnetic flux based on the pair of magnetic field generating coils 3, thereby exhibiting the operation based on the configuration (2). Can be.

[0021]

Embodiment 4 Embodiment 4 shows another example of the configuration (2). As shown in FIGS. 8 (a), 8 (b) and 8 (c), a pair of probes 4 are connected to a pair of magnetic fields. It is characterized in that it is arranged along the direction between the generating coils 3 and that these probes 4 are orthogonal to the MR element wafer 1 and the XYZ table 2 on which it is mounted.

Also in the fourth embodiment, since the closed circuit does not intersect with the magnetic flux, the operation based on the configuration (2) can be achieved.

[0023]

As described above, in the case of the present invention, as in the case of the prior art, a measurement error due to an induced voltage which is inevitably generated when the measurement is performed by changing the magnetic field is avoided, and the sensitivity of the MR element wafer is reduced. Since the magnetic properties can be accurately measured, the value of the present invention is enormous.

[Brief description of the drawings]

FIGS. 1A and 1B are a front view and a side view of a conventional magneto-sensitive device for an MR element wafer.

FIGS. 2 (a), 2 (b) and 2 (c) are a front view, a top view and a side view for explaining the operation principle of the structure of claim 1;

FIGS. 3 (a), 3 (b), 3 (c) are a front view, a top view, and a side view for explaining the operation principle of the constitution of claim 2;

FIGS. 4A and 4B are a front view and a side view showing a configuration in which a pair of magnetic field generating coils are arranged differently from the prior art shown in FIG.

FIGS. 5A, 5B, and 5C are a front view, a top view, and a side view showing the configuration of the first embodiment.

FIGS. 6A, 6B, and 6C are a front view, a top view, and a side view showing the configuration of the second embodiment.

FIGS. 7A, 7B, and 7C are a front view, a top view, and a side view showing the configuration of the third embodiment.

8A, 8B, and 8C are a front view, a top view, and a side view showing the configuration of the fourth embodiment.

[Description of sign]

 1: MR element wafer 2: XYZ stage 3: Magnet or magnetic field generating coil 31: Magnetic pole 32: Magnetic field line 4: Probe

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Akira Yoshino 689-3 Ogakiuchi, Wakayama City, Wakayama Prefecture Inside Osaka Wakado Kogyo Co., Ltd. Inside the company (72) Inventor Yasuyuki Ito 2-3-4 Nagatacho, Chiyoda-ku, Tokyo Inside Toki Tsusho Corporation (72) Inventor Masaru Namba Inside 2-3-4 Nagatacho, Chiyoda-ku, Tokyo Toki Tsusho Corporation (72) Inventor Shunji Sakurai 1-1-18-2 Hakusan, Midori-ku, Yokohama-shi, Kanagawa Prefecture Inside Carl SUSS Japan Co., Ltd. (72) Inventor Susumu Yagi 1-1-18-2 Hakusan, Midori-ku, Yokohama-shi, Kanagawa SUSS Japan Co., Ltd.

Claims (2)

(57) [Claims] 1. An apparatus for mounting a magnetic resistive element wafer on an XYZ stage and measuring the magnetic sensitivity of the magnet resistive element wafer by a magnetic field generated by a pair of magnetic field generating coils. projection line of <br/> pair of probes against the direction of the plane perpendicular to the direction connecting between the by placing the probe so that the crossed state, an apparatus for measuring the magneto-sensitive magnet resistive element. 2. A mounting a wafer of magnet-resistive elements on the XYZ stage, the device you measure the magneto-sensitive magnet resistive element wafer by the magnetic field generated by the pair of magnetic field generating coils, the pair of magnetic field generating projection line of a pair of probes against a plane orthogonal to the direction connecting the coils and place so that the state of being superimposed
The magnetic sensitivity of the magnet resistive element
To measure the equipment.