JP2014195097A - Magnetic field prober - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic field prober having high measurement accuracy which can apply a magnetic field from a magnetic field application device to a magnetic body device with high accuracy.SOLUTION: A magnetic field prober 1A(1) comprises: a magnetic field application device 3 having a magnetic field applying means 2; a probe card 6 having a probe pin 4; a stage 7 which is disposed underside of the magnetic applying means 2 and on which an object 20 to be measured is mounted; and a guide 8 which holds the probe card 6 so as to be almost parallel to one plane of the stage 7 between the magnetic field applying means 2 and the stage 7. A pair of magnetic field applying means 2 configuring a group can form a magnetic field which is warped so that the lowest part is positioned on the lower side of the middle part between the pair of magnetic field applying means 2. The tip of each probe pin 4 of the probe card 6 is disposed at a position which is inside a magnetic field formed in a curved shape between the couple of magnetic field applying means 2.

Description

  The present invention relates to a magnetic field prober.

As an apparatus for measuring a magnetic device at a wafer level, a wafer prober (magnetic field prober) equipped with a magnetic field application device is known (see, for example, Non-Patent Document 1).
A configuration example of a conventional magnetic field prober is shown in FIG. In this magnetic field prober 100, a probe card 104 having probe pins 103 is held by a guide 105 below a magnetic field applying device 102 having a magnetic field applying means 101. Such a magnetic field prober 100 has a structure for applying a magnetic field to a wafer 110 (measurement object) on which a magnetic device is formed, which is placed on a stage 106.

  At this time, in the leakage magnetic field type magnetic field application device 102 as shown in FIG. 5, the uniform range of the magnetic field is generally as narrow as 1 to several millimeters, and it is necessary to accurately install the probe pin 103 within the uniform magnetic field range. There is. For example, FIG. 6 is a graph showing the relationship between the distance in the Z direction from the magnetic field application device and the magnetic field when a 10 mT magnetic field is applied to a predetermined position. When the height changes from the predetermined position by about ± 0.2 mm, the magnetic field value changes by about ± 2%.

  Here, as shown in FIG. 7, the probe card 104 generally includes a prober main body by a guide 105 for holding the probe card and a card edge connector 107 for ensuring electrical continuity with the measuring instrument at the probe card edge 104a. Is attached.

  In a prober that does not apply a magnetic field, the height of the stage on which the wafer is installed is matched with the height of the probe pin measured by the alignment camera or the height of the probe pin visually confirmed with a microscope or the like. The absolute height accuracy of the probe pin and the probe card is not important, but the magnetic field prober changes the value of the magnetic field as described above due to the difference in the stage height (= wafer height). It is essential that the three Z-direction positional relationships of the apparatus (fixed), probe card (manual installation), and wafer (automatic alignment) are aligned in mm units.

Generally, in the probe card, the relative error in the height direction of the probe pin is about ± 5 μm, but the absolute height accuracy from the substrate to the tip of the probe pin is about ± 0.2 mm. It has been difficult to increase the magnetic field accuracy as a measurement system to within ± 2%.
Further, as described in, for example, Patent Document 1, Patent Document 2, and Patent Document 3, there is a method of providing a magnetic field application device on a probe card, but a coil is required for each probe card, and kOe ( It is difficult to apply a strong magnetic field of kilo-Oersted level.

JP 2007-147568 A JP 2007-57547 A JP 2006-24845 A

http://www.toei-tc.co.jp/top.html

  The present invention has been devised in view of such conventional circumstances, and provides a magnetic field prober that can apply a magnetic field from a magnetic field application device to a magnetic device with high accuracy and has high measurement accuracy. For the purpose.

According to a first aspect of the present invention, there is provided a magnetic field prober comprising: a magnetic field applying device having a magnetic field applying means; a probe card having a probe pin; and a stage placed on the lower side of the magnetic field applying means for placing an object to be measured. And a magnetic field prober disposed between the magnetic field applying means and the stage and holding the probe card substantially parallel to one surface of the stage, wherein the magnetic field applying device A pair of the magnetic field applying means provided apart from each other in the direction, and each of the pair of magnetic field applying means constituting the set is directed downward at an intermediate portion between the pair of the magnetic field applying means. A magnetic field can be formed in an obliquely downward direction, and the magnetic field applying device is configured to be able to form a curved magnetic field between the pair of magnetic field applying means so that a lowermost part is positioned below an intermediate portion thereof. The probe pins protrude downward from the probe card and are arranged in a direction along one surface of the stage, and the tips of the probe pins are positioned in the magnetic field that is curved between the pair of magnetic field applying means. It is characterized by being arranged.
A magnetic field prober according to a second aspect of the present invention is the magnetic field prober according to the first aspect, wherein the magnetic field prober is disposed between the magnetic field applying device and the guide, and the magnetic field applying means and the probe card are moved by moving the guide up and down. An adjustment mechanism capable of changing the distance between them is provided.
A magnetic field prober according to a third aspect of the present invention includes the adjustment mechanism according to the first aspect, wherein the distance between the magnetic field applying unit and the probe card can be changed by adjusting a height of the probe card. It is characterized by this.
A magnetic field prober according to a fourth aspect of the present invention is the magnetic field prober according to the third aspect, wherein the probe card includes a probe board made of a nonmagnetic metal and a printed board, and has a probe pin board having the probe pin. The probe pin substrate is placed on one surface of the probe board so as to be substantially parallel to one surface of the stage, and one of the probe boards is passed through an opening provided in the probe board. The probe pin protrudes from the surface side toward the other surface side.

  In the magnetic field prober of the present invention, by changing the height of the probe card held by the guide, the installation accuracy in the Z direction when the probe card is held by the guide can be improved without modifying the prober body. It becomes possible. As a result, it is possible to accurately install the probe pin in the uniform magnetic field range, and as a result, the magnetic field from the magnetic field applying device can be applied to the magnetic device with high accuracy. As a result, the present invention can provide a magnetic field prober with high measurement accuracy.

Sectional drawing which shows one structural example of the magnetic field prober which concerns on this invention. Sectional drawing which shows another structural example of the magnetic field prober which concerns on this invention. Sectional drawing which shows another structural example of the magnetic field prober which concerns on this invention. The top view which shows an example of the probe pin board | substrate which has a card edge connector. Sectional drawing which shows the structural example of the conventional magnetic field prober. The graph showing the relationship between the distance of a Z direction from a magnetic field application apparatus, and a magnetic field. The top view which shows an example of the probe card which has a card edge connector.

  Hereinafter, an embodiment of a magnetic field prober according to the present invention will be described with reference to the drawings.

<First embodiment>
FIG. 1 is a cross-sectional view schematically showing a configuration example of a magnetic field prober of the present invention.
This magnetic field prober 1A (1) is arranged on the lower side of the magnetic field applying means 2 with a magnetic field applying device 3 having a magnetic field applying means 2, a probe card 6 having probe pins 4 and a probe pin substrate 5, and a wafer 20 A stage 7 on which (object to be measured) is placed, and a guide 8 that is disposed between the magnetic field applying means 2 and the stage 7 and holds the probe card 6 substantially parallel to one surface of the stage 7. At least.
Such a magnetic field prober 1 </ b> A (1) measures an output when a certain magnetic field is applied to the wafer 20, which is an object to be measured, placed on the stage 7. The magnetic field prober 1 </ b> A (1) is made of a nonmagnetic material as appropriate in order to suppress the influence of an external magnetic field except for the magnetic field applying means 2.

The magnetic field prober 1A (1) according to the present invention is disposed between the magnetic field applying device 3 and the guide 8, and moves the guide 8 up and down to move between the magnetic field applying means 2 and the probe card 6. The adjustment mechanism 10 made of a non-magnetic material that can change the distance is provided.
In the magnetic field prober 1A (1) of the present invention, the height of the probe card 6 held by the guide 8 is changed to change the Z direction when the probe card 6 is held by the guide 8 without modifying the prober body. It becomes possible to improve the installation accuracy. As a result, the probe pin 4 can be accurately installed in the uniform magnetic field range, and as a result, the magnetic field from the magnetic field applying device 3 can be applied to the magnetic device with high accuracy. Specifically, the magnetic field uniformity can be controlled within ± 0.5%. As a result, the magnetic field prober 1A (1) of the present invention has high measurement accuracy.

The magnetic field application device 3 includes magnetic field application means 2. An example of the magnetic field applying means 2 is a solenoid coil. In the example shown in FIG. 1, one set (two) of magnetic field applying means 2 is arranged. However, in order to apply a magnetic field in the XY direction, two sets (four) of magnetic field applying means 2 are arranged. There is also.
The probe card 6 includes probe pins 4 and a probe pin substrate 5 on which the probe pins 4 are fixed. The probe pin substrate 5 is composed of a printed circuit board in order to ensure insulation of the probe pin portion.
The width of the probe card 6 is, for example, 4.5 inches (114.31 mm).

The stage 7 is for placing the wafer 20 to be measured on the lower side of the magnetic field applying means 2.
The guide 8 is disposed between the magnetic field applying means 2 and the stage 7 and holds the probe card 6 substantially parallel to one surface of the stage 7. The guide 8 has, for example, two guide members 8a having a substantially L-shaped cross section, and the two guide members 8a are arranged to face each other and are configured in a rail shape.

In particular, in the present invention, the distance between the magnetic field applying unit 2 and the probe card 6 can be changed by being arranged between the magnetic field applying device 3 and the guide 8 and moving the guide 8 up and down. An adjustment mechanism 10 made of a non-magnetic material is provided.
For example, the adjustment mechanism 10A (10) is installed at two places on one side of the guide 8 and at four places on both sides. In this adjustment mechanism 10A (10), the height can be adjusted by a rail with a micrometer or the like. Thereby, fine height adjustment becomes possible and the installation accuracy of the probe card 6 can be further improved.

Next, a magnetic field application method using such a magnetic field prober will be described.
The magnetic field application method of the present invention includes a step of inserting the probe card 6 into the card edge connector, a step of holding the probe card 6 on the guide 8, and a step of placing an object to be measured (wafer 20) on one surface of the stage 7. And a step of adjusting the distance between the probe card 6 and the magnetic field applying means 2 by the adjusting mechanism 10 made of a non-magnetic material.
In the magnetic field application method of the present invention, the adjustment mechanism 10 adjusts the distance between the probe card 6 and the magnetic field application means 2, so that the positions of the magnetic field application means 2, the probe card 6, and the object 20 to be measured are adjusted. Thus, it is possible to achieve alignment in the Z direction. Thereby, the magnetic field from the magnetic field application apparatus 3 can be accurately applied to the magnetic device. As a result, the magnetic field application method of the present invention can obtain highly accurate characteristics.

Hereinafter, a method for adjusting the distance between the probe card 6 and the magnetic field applying means 2 in the magnetic field prober 1A (1) of the present embodiment will be described.
First, the height of the tip of the probe pin 4 is measured with an alignment camera (not shown) for the probe pin provided in the prober body. The probe pin alignment camera is calibrated in advance, and by measuring the height of the tip of the probe pin 4, the height to the tip of the magnetic field applying means 2 and the probe pin 4 can be measured.

Next, the height of the guide 8 of the probe card 6 is adjusted by the micrometer of the adjustment mechanism 10A (10) so as to obtain an optimum height.
Next, the height of the probe pin 4 is measured again with the probe pin alignment camera provided in the prober body, and the magnetic field application means 2 and the tip of the probe pin 4 are measured. If necessary, the adjustment may be performed again.

  With the configuration as described above, the absolute height of the probe card 6 and the magnetic field application device 3 can be defined, so that the installation accuracy in the Z direction is improved, and as a result, the magnetic field uniformity can be controlled within ± 0.5%. It has become possible. In addition, errors between the probe cards can be removed, and the reproducibility when removing the probe card 6 is improved.

<Second embodiment>
Next, a second embodiment of the magnetic field prober of the present invention will be described.
FIG. 2 is a cross-sectional view showing an example of the magnetic field prober 1B (1) of the present embodiment.
In the following description, portions different from the above-described first embodiment will be mainly described, and description of similar portions will be omitted.

In the first embodiment described above, the adjusting mechanism 10A (10) is arranged between the magnetic field applying device 3 and the guide 8. However, the magnetic field prober 1B (1) of the present embodiment has the probe pin 4. The probe card 6 has an adjusting mechanism 10B (10) made of a nonmagnetic material. This adjustment mechanism 10B (10) is arranged between the probe card 6 and the magnetic field application device 3, for example.
In the present embodiment, a height adjustment mechanism 10 </ b> B (10) is added to the edge portion of the probe card 6. A movable spacer 10b is provided below the edge portion of the probe card 6, and adjustment is performed with a micrometer or the like. In the present embodiment, there is an advantage that the modification of the prober main body is unnecessary as compared with the case of the first embodiment.
For example, the adjustment mechanism 10B (10) is installed at two places on one side of the probe card 6 and at four places on both sides. Thereby, the installation accuracy of the probe card 6 can be further improved.

Hereinafter, a method for adjusting the distance between the probe card 6 and the magnetic field applying means 2 in the magnetic field prober 1B (1) of the present embodiment will be described.
First, the height of the tip of the probe pin 4 is measured with an alignment camera (not shown) for the probe pin provided in the prober body. The probe pin alignment camera is calibrated in advance, and by measuring the height of the tip of the probe pin 4, the height to the tip of the magnetic field applying means 2 and the probe pin 4 can be measured.

Next, the height of the card edge of the probe card 6 is adjusted by the micrometer of the adjusting mechanism 10B (10) so as to obtain an optimum height. At this time, if the probe card 6 seems to bend due to insufficient rigidity of the probe card 6, the edge portion may be made of a nonmagnetic metal (Al or the like).
Next, the height of the probe pin 4 is measured again with the probe pin alignment camera provided in the prober body, and the magnetic field application means 2 and the tip of the probe pin 4 are measured. If necessary, the adjustment may be performed again.

  With the configuration as described above, the absolute height of the probe card 6 and the magnetic field application device 3 can be defined, so that the installation accuracy in the Z direction is improved, and as a result, the magnetic field uniformity can be controlled within ± 0.5%. It has become possible. In addition, errors between the probe cards can be removed, and the reproducibility when removing the probe card 6 is improved.

<Third embodiment>
Next, a third embodiment of the magnetic field prober of the present invention will be described.
FIG. 3 is a cross-sectional view showing an example of the magnetic field prober 1C (1) of this embodiment.
In the following description, portions different from the above-described first embodiment will be mainly described, and description of similar portions will be omitted.

In the magnetic field prober 1 </ b> C (1) of the present embodiment, the probe card 6 includes a probe board 9 made of a nonmagnetic metal and a printed board, and has a probe pin substrate 5 having the probe pins 4.
The probe pin substrate 5 is placed on one surface of the probe board 9 so as to be substantially parallel to one surface of the stage 7, and through the opening 9 c provided in the probe board 9. The probe pin 4 protrudes from one surface side of the probe board 9 to the other surface side, and the probe pin substrate 5 has an adjusting mechanism 10C (10) made of a nonmagnetic material.

In the magnetic field prober 1C (1) of this embodiment, the probe pin substrate 5 constituting the probe card 6 has an adjusting mechanism 10C (10) made of a nonmagnetic material. Then, a height adjusting mechanism 10C (10) is arranged between the probe board 9 and the probe pin substrate 5, and the space between the probe board 9 and the probe pin substrate 5 is varied in the height direction.
For example, the adjustment mechanism 10C (10) is installed at two locations on one side of the probe pin substrate 5 and at four locations on both sides. The adjustment mechanism 10C (10) has, for example, a screw structure, and the height is adjusted by this screw structure. Thereby, fine height adjustment becomes possible and the installation accuracy of the probe card 6 can be further improved. In the present embodiment, the adjusting mechanism 10C (10) also has a fixing mechanism for the probe pin substrate 5 and the probe board 9.
In this embodiment, compared with the case of 1st Embodiment and 2nd Embodiment, since the rigidity of the probe card 6 is high, there exists an advantage which is easy to maintain high precision. In addition, the blower body need not be modified.

  The probe board 9 is made of a nonmagnetic metal, and for example, an aluminum (Al) plate having a thickness of 5 mm can be used. By using a nonmagnetic metal having high rigidity, the probe pin 4 can be installed with high accuracy in a uniform magnetic field range. In addition, the probe board 9 is not limited to a nonmagnetic metal, For example, you may comprise with nonmagnetic materials, such as resin.

The probe pin substrate 5 is composed of a printed circuit board in order to ensure insulation of the probe pin portion.
The probe pin substrate 5 is placed on one surface 9a of the probe board 9 and fixed to the probe board 9 by, for example, an adjustment mechanism 10C. Further, the probe pin 4 protrudes from the one surface 9a side of the probe board 9 toward the other surface 9b side through the opening 9c provided in the probe board 9.
Further, as shown in FIG. 4, the card edge connector 30 ensures electrical continuity via a contact 31 provided on the probe pin substrate 5.

Next, a method for adjusting the distance between the probe card 6 and the magnetic field application unit 2 in this embodiment will be described.
First, the height of the tip of the probe pin 4 is measured with an alignment camera (not shown) for the probe pin provided in the prober body. The probe pin alignment camera is calibrated in advance, and by measuring the height of the tip of the probe pin 4, the height to the tip of the magnetic field applying means 2 and the probe pin 4 can be measured.

Next, the height of the card edge of the probe card 6 is adjusted with a micrometer so as to obtain an optimum height.
Next, the height of the probe pin 4 is measured again with the probe pin alignment camera provided in the prober body, and the magnetic field application means 2 and the tip of the probe pin 4 are measured. If necessary, the adjustment may be performed again.

  With the configuration as described above, the absolute height of the probe card 6 and the magnetic field application device 3 can be defined, so that the installation accuracy in the Z direction is improved, and as a result, the magnetic field uniformity can be controlled within ± 0.5%. It has become possible. In addition, errors between the probe cards can be removed, and the reproducibility when removing the probe card 6 is improved.

  Although the magnetic field prober and the magnetic field application method of the present invention have been described above, the present invention is not limited to this, and can be changed as appropriate without departing from the spirit of the invention.

  The present invention is widely applicable to a magnetic field prober and a magnetic field application method.

  1A, 1B, 1C (1) Magnetic field prober, 2 Magnetic field applying means, 3 Magnetic field applying device, 4 Probe pin, 5 Probe pin substrate, 6 Probe card, 7 Stage, 8 Guide 9 Probe board, 9c Opening, 10A, 10B , 10C (10) Adjustment mechanism, 20 wafer (object to be measured).

Claims (4)

A magnetic field application device having a magnetic field application means;
A probe card having probe pins;
A stage disposed under the magnetic field applying means and for placing an object to be measured;
A magnetic field prober provided at least with a guide disposed between the magnetic field applying means and the stage and holding the probe card substantially parallel to one surface of the stage;
The magnetic field application device has a set of the magnetic field application means provided to be separated from each other in the lateral direction of the device, and a pair of the magnetic field application means constituting the set is respectively between the pair of the magnetic field application means. The magnetic field application device can form a magnetic field that curves between the pair of magnetic field application means so that the lowermost part is located below the intermediate part. Composed of
The probe pins protrude downward from the probe card and are arranged in a direction along one surface of the stage, and the tips of the probe pins are positioned in the magnetic field that is curved between the pair of magnetic field applying means. A magnetic field prober characterized by being arranged.   An adjustment mechanism that is disposed between the magnetic field application device and the guide and is capable of changing a distance between the magnetic field application unit and the probe card by moving the guide up and down; The magnetic field prober according to claim 1.   The magnetic field prober according to claim 1, further comprising an adjusting mechanism capable of changing a distance between the magnetic field applying unit and the probe card by adjusting a height of the probe card. The probe card is composed of a probe board composed of a nonmagnetic metal and a printed circuit board, and has a probe pin substrate having the probe pin,
The probe pin substrate is placed on one surface of the probe board so as to be substantially parallel to one surface of the stage, and through the opening provided in the probe board, on one surface side of the probe board The magnetic field prober according to claim 3, wherein the probe pin protrudes from the surface toward the other surface.

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