JP2011014634A - Probe card and method for applying magnetic field - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a probe card which can precisely measure the magnetic field generated by a planar coil and can measure the magnetic field actually applied to a device during measurement, as well.SOLUTION: The probe card 1 includes four planar coils arranged respectively at locations, where the coils make 90 degrees mutually with an identical distance from a center point on one face or the other face of a probe card substrate, when a predetermined point on the one face or the other face of a probe card substrate 2 is used as the center point and an axis passing the center point and vertical to the one face is used as a center axis; a probe pin 4 arranged to protrude to the other face side of the probe card substrate; and a magnetic sensor 5 arranged at a location on the center axis with a height from the center of the thickness of the planar coil which is identical to the distance between the center of the thickness of the plane coil and a probe pin leading edge on the one face side of the probe card substrate for detecting the magnetic field generated by the planar coil.

Description

  The present invention relates to a probe card and a magnetic field application method.

As an apparatus for measuring a magnetic device at a wafer level, a probe card (coil-integrated probe card) in which a magnetic field application device is integrated is known (for example, see Patent Document 1).
When inspecting a device using such a probe card, the relationship between the current applied to the coil and the magnetic flux density actually measured on the device portion is important.

This relationship is usually the relationship between the current flowing in the magnetic field application device and the magnetic field while applying a magnetic field to a magnetic flux density measuring device (for example, a gauss meter) installed in advance so as to be the same height as the tip of the probe pin. Must be created as a table (or function), and the magnetic field applied to the device during actual measurement could not be measured.
For this reason, in order to measure the magnetic field actually applied to the device (device to be measured) and set it to a desired magnetic field, it has not been possible to perform feedback control on the power supply of the magnetic field applying means.

JP 2007-147651 A

The present invention has been devised in view of such a conventional situation, and can accurately measure a magnetic field generated by a planar coil (magnetic field applying means). The first object of the present invention is to provide a probe card capable of measuring a magnetic field that is actually applied.
Further, according to the present invention, it is possible to apply a desired magnetic field to the device (measurement object) by adjusting the current value to be applied to the planar coil based on the strength of the magnetic field detected by the magnetic sensor. A second object is to provide a magnetic field application method.

The probe card according to claim 1 of the present invention is a probe card used for a magnetic field prober, and has a predetermined point on one surface or the other surface of the probe card substrate as a central point, and passes through the central point on the one surface. When the vertical axis is the central axis, the four distances from the center point are the same on one surface or the other surface of the probe card substrate, and the four planar coils are disposed at positions that are 90 degrees from each other; The probe pin arranged to protrude on the other surface side of the probe card substrate, and the height from the center of the thickness of the planar coil on one surface side of the probe card substrate is the center of the thickness of the planar coil and the A magnetic sensor that detects the magnetic field generated by the planar coil and is disposed at a position on the central axis that is the same as the distance from the tip of the probe pin.
The probe card according to claim 2 of the present invention is characterized in that, in claim 1, the four planar coils have the same number of turns, winding direction and size.
A probe card according to a third aspect of the present invention is the probe card according to the first or second aspect, wherein the magnetic sensor is supported at the position by a guide made of a non-magnetic material.
According to a fourth aspect of the present invention, there is provided a magnetic field applying method comprising: a planar coil disposed on one surface of a probe card substrate; a probe pin disposed projecting on the other surface side of the probe card substrate; On one side or the other side, the height from the center of the thickness of the planar coil is the same as the distance between the center of the thickness of the planar coil and the tip of the probe pin, and the position on the central axis And a magnetic sensor for detecting a magnetic field generated by the planar coil, and a magnetic field applying method using a magnetic field prober using a probe card, wherein a magnetic flux density value obtained by the magnetic sensor is used. Then, feedback control is performed on a power source that drives the planar coil, and a magnetic field generated by the planar coil is adjusted.

In the probe card of the present invention, on one side of the probe card substrate, the magnetic field generated by the planar coil is placed at a position where the height from the center of the planar coil is the same as the distance between the planar coil and the probe pin tip. Since the magnetic sensor to detect is arranged, the magnetic field generated by the planar coil can be accurately measured. As a result, the present invention can provide a probe card capable of measuring the magnetic field applied to the device (measurement object) based on the strength of the magnetic field detected by the magnetic sensor. .
In the magnetic field application method of the present invention, feedback control is performed on the power source that drives the planar coil using the magnetic flux density value obtained by the magnetic sensor, and the magnetic field generated by the planar coil is adjusted. Yes. Accordingly, in the present invention, a magnetic field capable of applying a desired magnetic field to the device (measurement object) by adjusting a current value to be applied to the planar coil based on the strength of the magnetic field detected by the magnetic sensor. An application method can be provided.

Sectional drawing which shows typically the example of 1 structure of the probe card based on this invention. The top view of the probe card shown in FIG.

  Hereinafter, an embodiment of a probe card and a magnetic field application method according to the present invention will be described with reference to the drawings.

1 and 2 are diagrams schematically showing a configuration example of a probe card according to the present invention. FIG. 1 is a cross-sectional view taken along line AA ′ in FIG. 2, and FIG. 2 is a plan view.
The probe card 1 of the present invention is a probe card used in a magnetic field prober, and a predetermined point on the one surface 2a or the other surface 2b of the probe card substrate 2 is defined as a center point α, and the one surface 2a passes through the center point α. When the axis perpendicular to the center axis β is the center axis β, the distance from the center point α is the same on the one surface 2a or the other surface 2b of the probe card substrate 2, and they are arranged at positions that are 90 degrees from each other. Four planar coils 3a to 3d, probe pins 4 projecting from the other surface 2b of the probe card substrate 2, and the thickness of the planar coils 3a to 3d on the one surface 2a side of the probe card substrate 2 Is equal to the distance between the center of the thickness of the planar coils 3a to 3d and the tip of the probe pin 4 and is disposed at a position on the central axis. A magnetic sensor 5 for detecting the magnetic field generated by 3d, characterized by comprising a.

  In the probe card 1 of the present invention, the height from the center of the planar coils 3a to 3d is the same as the distance between the center of the planar coils 3a to 3d and the tip of the probe pin 4 on the one surface 2a side of the probe card substrate 2. Since the magnetic sensor 5 for detecting the magnetic field generated by the planar coils 3a to 3d is disposed at a position on the central axis β, the magnetic field generated by the planar coils 3a to 3d can be accurately measured. . As a result, the probe card 1 of the present invention can measure the magnetic field applied to the device based on the strength of the magnetic field detected by the magnetic sensor 5.

The probe card 1 has a probe pin 4 and a probe card substrate 2 to which the probe pin 4 is fixed. The probe card substrate 2 is composed of a printed circuit board in order to ensure insulation of the probe pin portion.
The width of the probe card 1 is, for example, 4.5 inches (114.3 mm).
As shown in FIG. 2, a card edge connector 7 is provided at one end of the probe card 1.

  The planar coils 3a to 3d are, for example, spiral coils and are magnetic field applying means. In the example shown in FIG. 1, two sets (four) of planar coils 3 a to 3 d are arranged to apply a magnetic field in the XY directions. For example, the planar coils 3b and 3d form a magnetic field in the X direction, and the coils 3a and 3c form a magnetic field in the Y direction. It is also possible to form a magnetic field with an angle or a rotating magnetic field by appropriately controlling both sets of magnetic fields.

  The four planar coils 3a to 3d are distances from the center point α on the one surface 2a of the probe card substrate 2 when a predetermined point on the one surface 2a of the probe card substrate 2 is the center point α. Are the same, and are arranged at positions that are 90 degrees from each other. These four planar coils 3a to 3d preferably have the same number of turns, winding direction and size. Further, among the four planar coils 3a to 3d, the opposed planar coils 3a to 3d may be electrically connected or may not be connected.

  1 and 2 show a case where the planar coils 3a to 3d are arranged on the one surface 2a of the probe card substrate 2, the planar coils 3a to 3d may be formed on the other surface 2b. Good. Thereby, the magnetic sensor 5 can be lowered. Further, since the distance to the object to be measured is short, the strength of the magnetic field can be increased even with the same current value.

The magnetic sensor 5 detects a magnetic field generated by the planar coils 3a to 3d.
In particular, in the probe card 1 of the present invention, the magnetic sensor 5 has a height from the center of the thickness of the planar coils 3a to 3d on the one surface 2a side of the probe card substrate 2. It is arranged at a position that is the same as the distance between the center of the thickness of 3d and the tip of the probe pin 4.

  For example, in the example shown in the figure, the height from the center of the planar coil formed on the probe card 1 to the tip of the probe pin 4 is 2.8 ± 0.1 mm, for example. 2.8 mm above the upper surface of the probe card 1 and in the XY direction, the center of the planar coil 3b—the center axis of the planar coil 3d, and the center of the planar coil 3a—the center axis of the planar coil 3c. The magnetic sensor 5 is installed at a position, that is, a position substantially at the center of the magnetic field formed by the magnetic field applying means (planar coils 3a to 3d). Here, the starting point of h in FIG. 2 is the center of the thickness of the planar coils 3a to 3d.

  By arranging the magnetic sensor 5 at the above position, it is possible to measure the value of the magnetic flux density applied from the magnetic field application device during measurement of the device (measurement object). In addition, it is possible to apply a desired magnetic field by feeding back the measured value of the magnetic flux density to the power source that drives the coil.

As such a magnetic sensor 5, for example, an MR sensor, a Hall sensor, an MI sensor, a fluxgate sensor, or the like can be used.
The magnetic sensor 5 is supported at the position by a guide 6 made of a nonmagnetic material such as Teflon (registered trademark), plastic, or Al.
Two magnetic sensors 5 may be installed in directions orthogonal to each other, or one magnetic sensor 5 may be rotated by providing a rotation shaft.

Hereinafter, a magnetic field application method using such a probe card 1 will be described.
The magnetic field application method of the present invention includes a planar coil 3 disposed on one surface 2a or the other surface 2b of the probe card substrate 2, a probe pin 4 disposed so as to protrude toward the other surface 2b of the probe card substrate 2, On the one surface 2 a side of the probe card substrate 2, the height from the center of the thickness of the planar coil 3 is the same as the distance between the center of the thickness of the planar coil 3 and the tip of the probe pin 4. A magnetic field applying method by a magnetic field prober using a probe card 1 provided with a magnetic sensor 5 for detecting a magnetic field generated by the planar coil 3 disposed at a position, and a magnetic flux obtained by the magnetic sensor 5 Feedback control is performed on the power source that drives the planar coil 3 using the density value, and the magnetic field generated by the planar coil 3 is adjusted.

  In the magnetic field application method of the present invention, the magnetic sensor 5 is arranged at the position in the magnetic field prober used, thereby measuring the value of the magnetic flux density applied from the magnetic field application device during measurement of the device (measurement object). It has become possible. Then, using the magnetic flux density value obtained by the magnetic sensor 5, feedback control is performed on the power source that drives the planar coil 3 to adjust the magnetic field generated by the planar coil 3. As a result, in the magnetic field application method of the present invention, it is possible to apply a desired magnetic field to the device by adjusting the current value applied to the planar coil 3 based on the strength of the magnetic field detected by the magnetic sensor 5. Become.

  The probe card and the magnetic field application method of the present invention have been described above, but the present invention is not limited to this, and can be appropriately changed without departing from the spirit of the invention.

  The present invention is widely applicable to probe cards and magnetic field application methods.

  1 probe card, 2 probe card substrate, 3a to 3d planar coil, 4 probe pin, 5 magnetic sensor, 6 guide.

Claims (4)

A probe card used in a magnetic field prober,
When a predetermined point on one surface or the other surface of the probe card substrate is a central point, and an axis passing through the central point and perpendicular to the one surface is a central axis,
Four planar coils disposed on the one side or the other side of the probe card substrate, the distances from the center point being the same, and arranged at positions that are 90 degrees from each other;
Probe pins arranged to protrude on the other side of the probe card substrate;
On one surface side of the probe card substrate, the height from the center of the thickness of the planar coil is the same as the distance between the center of the thickness of the planar coil and the tip of the probe pin, and on the central axis A probe card comprising: a magnetic sensor that detects a magnetic field generated by the planar coil disposed at a position.   The probe card according to claim 1, wherein the four planar coils have the same number of windings, winding direction, and size.   The probe card according to claim 1, wherein the magnetic sensor is supported at the position by a guide made of a nonmagnetic material. A planar coil disposed on one surface or the other surface of the probe card substrate; a probe pin disposed projecting on the other surface side of the probe card substrate; and a thickness of the planar coil on the one surface side of the probe card substrate The height from the center is the same as the distance between the center of the thickness of the planar coil and the tip of the probe pin, and the magnetic field generated by the planar coil arranged at a position on the central axis is detected. A magnetic field application method by a magnetic field prober using a probe card equipped with a magnetic sensor,
A magnetic field application method comprising: performing feedback control on a power source that drives the planar coil using a magnetic flux density value obtained by the magnetic sensor, and adjusting a magnetic field generated by the planar coil.

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