JPH02156649A - Prober - Google Patents

Abstract

PURPOSE:To automate an alignment operation of a probe needle and to realize an unmanned automatic measuring operation by a method wherein a position of the probe needle is recognized on the basis of a relative position between a contact member and the probe needle. CONSTITUTION:A probe card 7 is set up; a touch plate 10 on an X-Y stage 3 is shifted to the neighborhood of a probe needle 6. Then, the plate 10 is raised in a Z-direction by using a pulse motor 102 and is brought into contact with the needle 6. A position of a conical face on the surface of the plate 10 is found and stored. Then, the plate 10 is lowered; when a plurality of positions ot the stored conical face are obtained, the number of intersections of a plurality of conical faces is found. Then, coordinates of the intersections are computed; thereby, it is possible to find a tip position of the needle.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention automatically aligns the bonding pad of a semiconductor device and the probe needle of a probe card in a prober used for testing semiconductor devices on a substrate. This is about a prober.

[Prior Art] Conventionally, alignment of the bonding pads of a semiconductor element and a group of probe needles in a prober has been performed using a so-called manual operation in which relative alignment is performed so that these positions match within the field of view of a stereomicroscope. There were many things.

In addition, when performing the above alignment operation, as disclosed in Japanese Patent Publication No. 59-5641, for example, a group of probe needles is pressed against a dummy wafer to form a group of needle holes on the wafer, and the position of the group of needle holes is Indirect alignment methods have been devised to detect .

[Problems to be Solved by the Invention] However, this manual alignment work is extremely time-consuming and labor-intensive. Furthermore, since the accuracy of setting the position of the probe needle in this operation is determined by the skill level of the operator, it has become one of the unstable factors in the measurement of semiconductor devices.

Therefore, there is a strong desire to automate the positioning of the probe needle, and the above-mentioned Japanese Patent Publication No. 59-5641 was one proposal for this purpose. However, this method has the drawback of requiring the use of consumables such as dummy wafers.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a prober that measures the electrical characteristics of an element formed on a substrate by bringing the probe needle into contact with an electrode of the element. On the other hand, the contact member is provided with a contact member movable relatively in at least the X and The position of the probe needle is recognized based on the relative position between the contact member and the probe needle.

Suitably, the contact surface of the contact member with respect to the probe needle has, for example, a conical shape, a polygonal shape, or two types of conical shapes having different apex angles.

"Operation" In a blower that measures the electrical characteristics of an element on a substrate through a probe needle, it is necessary to accurately position the probe needle on the electrode pad of the element, etc. The position of the needle is recognized, and in the present invention this is done automatically based on the position of the contact member when it contacts the probe needle. In other words, the position of the contact surface of the contact member with respect to the probe needle is determined by the position of the contact member. For example, if the contact surface is conical, etc., the equation of the contact surface at the time of contact is determined by the position (coordinates of the apex) of the contact member at that time. Since the coordinates of the tip of the probe needle related to the contact exist in this equation, the coordinates of the tip of the probe needle are specified by finding a plurality of this equation based on a plurality of contacts at different positions. At this time, the contact member is moved, for example, integrally with an XY stage that drives the substrate in the XYX directions.

After the coordinates of the probe needle tip are detected in this way,
Normally, the substrate is automatically positioned with respect to the probe needle based on the detected probe needle tip position by the XY stage and the θZ stage that drives the substrate thereon in the 02 direction. However, at this time, consumables such as dummy wafers are not required, and no manual operation is required.

[Example] Hereinafter, the present invention will be described in detail using examples shown in the drawings.

FIG. 1 is a schematic diagram of the upper part of a wafer blowbar showing an embodiment of the present invention. In this figure, 1 is a wafer chuck for mounting the wafer on a wafer, and 2 is a wafer chuck for driving the wafer chuck 1 in the θ and Z directions. θ2 stage, 3 is θ2 stage 2
This is an XY stage that drives the XYX direction, and includes an X stage 301 and a Y stage 302. X stage 3
01 is a guide 30 fixedly supported by a base (not shown)
4. Moves guided by 305, and Y stage 302 moves to
Guide 306.3 fixedly supported on stage 301
Guided by 07, we move. The X stage 301 includes a position detector that detects the position in the X direction via a scale (not shown), and the Y stage 302 includes a position detector that detects the position in the Y direction via a scale (not shown).

4 is a capacitive sensor for measuring the outer shape of the cube and the position (height) in the Z direction of the cube; 5 is an imager for capturing an image of the IC chip pattern on the wafer;
It has a microscope 501 and a TV camera 502. 6 is I
C is a probe needle for making electrical contact with the bonding pad on the chip; F is a probe card which is a printed circuit board on which the probe needles 6 are arranged and fixed; and 10 is a touch plate (not shown) for movable in two directions. It has a drive mechanism and a control section. Furthermore, the touch plate IO has an energization detector (not shown) that confirms contact by electrical continuity when the touch plate 10 is brought into contact with the probe needle 6.

FIG. 2 is a detailed view of the touch plate 1o, showing a state in which the touch plate io, which has a conical upper surface, is in contact with the probe needle 6. Further, 101 is a ball screw for driving the touch plate 10 in two directions, and 102 is a pulse motor for rotating the ball screw 101.

Hereinafter, the operation of detecting the tip position of the probe needle 6 in the apparatus shown in FIGS. 1 and 2 will be explained based on the flowchart shown in FIG. 3. Note that here, for the sake of simplification, the number of probe needles 6 is one.

When the detection operation is started, the operator first sets the probe card in step 201, and then operates the start switch on the operation panel (not shown) to proceed to step 202, where the movement of the XY stage 3 is started.
The touch plate 10 supported on the Y stage 3 moves to the vicinity where the probe needle 6 is located. Next, in step 203, the pulse motor 102 shown in FIG. 2 starts rotating the ball screw 101, and the touch plate 10 moves up in the Z direction. When the touch plate 10 rises, it comes into contact with the probe needle 6, and the rotation of the pulse motor 102 is stopped by an energization detector (not shown), and the process returns to step 204. In step 204, the position of the conical surface on the top surface of the touch plate 10 is determined based on the number of pulses given to the position detector (not shown) of the XY stage 3 and the pulse motor 102, and the position is stored in a storage circuit (not shown). Next, in step 205, the touch plate 10 is lowered by reversing the pulse motor 102. Next, step 206
Now, if the position of the conical surface on the top surface of the touch plate 10 stored in the memory circuit is one point, return to step 202 and select X.
Touch plate 1 by moving Y stage 3
0 to a predetermined position and repeat steps 203 to 20.
Execute 6. When it is determined in step 6 that the positions of the plurality of conical surfaces have been stored, in step 207, the number of intersections of the plurality of conical surfaces is determined from the stored positions of the plurality of touch plates 10. If there are multiple intersections, the process returns to step 202 and steps 203 and subsequent steps are executed again. If there is one point of intersection, the process proceeds to step 208 and the coordinates of the point of intersection are calculated, thereby making it possible to know the tip position of the probe needle. Here, in the XY stage movement in step 202, the touch plate 10 is moved to the vicinity where the probe needle is located at the first time, but even if the touch plate 10 and the probe needle 6 are moved up in step 203 thereafter, the XY force is applied to the touch plate 10 and the probe needle 6. There are cases where the direction is shifted and there is no contact. In this case, after lowering the touch plate 10, it is moved by a predetermined amount in the XY force direction, and step 203
Execute the following again. This series of operations is performed in step 203.
Please note that if there is no contact even after doing this, be sure to do so.

Next, we will show concrete calculation formulas for the operations described above.
The coordinates of the apex of the conical surface of the touch plate 10 are (Xo, 3
'o, Zo), the rotation center of the conical surface is parallel to the Z axis, so the equation of the conical surface is (X-Xo) 2+
(3'-3'o)" + k(Z-Zo)" -0
It is. Here, k is a constant determined by the shape of the conical surface. Furthermore, if the height from the apex of the conical surface of the touch plate 1o to the bottom end of the conical surface is h, then Zo −h≦2≦Z
o...(1).

In the first step 203, the apex of the conical surface of the touch plate 10 is the point A (X An 'I An Z A
), and when the touch plate 10 contacts the tip la of the probe needle 6, the coordinates of the tip a are (x, y.

2), the tip a point is (x-xA) 2+ (y-yA) ' +k(z-z
a) ” -0... (2) Exists on the conical surface.

In the second step 203, the apex of the conical surface of the touch plate 10 is at point B (X an V B + Z a )
touch plate 1 to the tip a of probe needle 6.
When 0 makes contact, the tip a point is (X-Xa) ' + (y-ya) '' +k (z-
z,,) 2-0...(3) Exists on the conical surface.

Furthermore, in the third step 203, when the apex of the conical surface of the touch plate 10 rises to the 0 point (Xc, yc, ZC) and the touch plate 10 contacts the tip a of the probe needle 6, the eia point is (X-Xc ) ” + (y-Yc) ” +k(z-
z□ ” sa O... (4) Exists on the conical surface.

The position of the tip a point (x, y, z) can be determined from equations (1) to (4).

Next, there are several methods as follows regarding how to set an energization detector (not shown) that detects energization between the probe needles 6 and the touch plate 10 when there are a plurality of probe needles 6.

■ A method of setting the energization detector so that each of the plural probe needles 6 has an independent sensor function, in this case, it is clear which probe needle 6 among the plurality of probe needles 6 the touch brake 10 has contacted be.

■ Attach the touch plate 10 to any of the multiple probe needles 6.
In this case, it is unclear which of the plurality of probe needles 6 the touch plate 10 has contacted.

■ Similar to (■) above, if the touch plate 10 comes into contact with any of the plurality of probe needles 6, the energization detector outputs a signal, that is, the function of an output signal for all probe needles 6, and for some specific probe needles 6. Only touch plate 10
A method in which the energization detector has the function of issuing a different detection signal when it comes into contact with the current detector.

■ A method of classifying a plurality of probe needles 6 into a plurality of groups and setting the energization detector to have a sensor function. In other words, when the probe needle 6 and the touch plate 10 come into contact with each other based on the energization detection signal, the contacted needle Although it is not possible to specify the probe needle 6 into groups, it is possible to confirm which group the probe needle 6 has come into contact with among the groups.

In the above-mentioned energization detection method, when the touch plate 10 comes into contact with any of the probe needles 6, the energization detector outputs a signal. It is possible to detect contact by measuring the load generated by contacting the touch plate 10.

FIG. 4 is a schematic diagram when a load sensor is incorporated into the touch plate 10, and 8 is a transducer (hereinafter referred to as a load cell) that detects a minute load applied to the touch plate 10;
81 is a load cell element, and 82 is a notch for concentrating stress at a specific location when a load is applied to the end of the load cell element 81. 83 is a strain gauge that measures the amount of deformation due to stress concentration on the notch 82 of the load cell element;
It is glued in four places in pairs, and has the function of converting minute loads into electrical signals.

The touch plate 10 is moved up and down via the load cell 8 by a vertical movement mechanism (not shown), and the strain gauge 8
Contact between the probe needle 6 and the touch plate 10 can be confirmed by observing the change in resistance at 3. Load determination using a load cell has a resolution of 10 mg or less, and can be used in place of a contact-based energization detector.

In addition, the relative position of each probe needle in the probe needle group by the probe needles 6 arranged on the probe card 7 is determined by the position of the bonding pad of the semiconductor element that is the object to be measured. The quality of the probe card is determined by measuring the position of each probe needle 6 relative to a reference surface for attaching the probe card 7 to a card holder (not shown).
It is possible to measure the position in the Z direction and the relative position in the XY force direction of each probe needle 6. Therefore, the operator of the blower can measure the position of the probe needles 6 (not shown) in the Information about the Z-direction position of the card holder with respect to the probe card mounting reference plane and the relative position of each probe needle can be input in advance into the memory circuit of the blower.

Next, a method of setting up a probe card 7 having a plurality of probe needles 6 and measuring the position of the probe needles 6 using the energization detection function described in (2) above will be described.

In step 203 of FIG. 3, when the apex of the conical surface of the touch plate 10 rises to point A (XA, yA, 2^) and contacts the tip a of one of the probe needles, the coordinates of the tip a are (Xa, 3'a, Za) then the first @a
The point is (Xa-XA)' + (ya-yA)' +k(za
-xA)' = 0 (5) Exists on the conical surface.

Similarly, the apex of the conical surface of the touch plate 10 is point B (xB
r ya12!1 ) and when it touches the tip of one of the probe needles, the coordinates of the tip are set to (
Br V b + Z b ), then the tip point is (Xb
-Xa)" + (yb-Va)" +k(Zb-Va
)' -0...(6) Exists on the conical surface.

Furthermore, the apex of the conical surface of the touch plate 10 is the 0 point (X
If the coordinates of the tip d when it touches the tip d of one of the probe needles when it rises to D+ 3' D+ Z O) are (Xd, yd, zd), the tip d point is (Xd - Xo
)” + (yd-Yo)'+k(z,,-zo)'
= 0...(7) Exists on the conical surface.

In addition, the relative positions of the tips a, b, and d, that is, the height (Z-axis direction) and the distance in the XY plane with respect to the card holder mounting reference plane are known values, and the probe card 7 is attached to the card holder (not shown). The probe card mounting surface of the card holder and the XY
Since the XY planes of the stage 3 are parallel, the positional relationship of the probe needles on the blowbar is only rotated around an axis parallel to the Z axis. Therefore, the coordinates of the tip a point (xa,'/ a, Z a ), the coordinates of the tip s point (X biyb+Z b ), and the coordinates of the tip d point (
Xll.

In the relationship Xa-Xb
+ Va"Yb -k+ """ (8) Xl, -X
I + yb+3'd-kt...'(9) Xa-
ydo Va"yd=ks """ (10) is a known value (k+, kz, and ks are constants).

In equations (5) to (lO), by calculating these with a CPU (not shown), the variable (unknown value) X
@ , X b + X d + 'J m *'
/ b r 3' d can be found.

Here, we considered 2□z,...,z- to be known values for the height (Z-axis direction) with respect to the card holder mounting reference plane, but the If the height is unknown and the relative positions of the probe needles 6 are known, then if h is the difference in height between the apex of the conical surface of the touch plate 10 and the lower end of the conical surface, Za-h≦2. ．． ≦z A...= (11) Za-h≦
Zb≦z a ・・・・・・(12) Zo−h≦z
d≦z, the expression “-”-(13) holds true. Furthermore, Z a -Z b -k4 ...(14) Za
-Za -ks 4. The value of (15), that is, the constant. ks is a known value, and formula (5) ~
By calculating (15), (Xa, 3'a).

Za ) + (Xb+)'b+Zb ) + (Xd
+yd+zd).

Also, the apex of the conical surface of the touch plate 10 is point A (XA
, )'A, Z^) When it comes into contact with the tip a of one of the probe needles, after the touch plate 10 is lowered, a predetermined amount of microscopic stent is deposited near the x-y coordinates of point A. The coordinates of the tip t4a were identified by repeating the operation to find the point of contact with the tip a again (using the same method as for one probe needle mentioned earlier) until the coordinates of the tip a were determined. After that, move to the above point B and move to the tip i4b in the same way as the tip a.
It is also possible to determine the position of the probe needle 6 by determining the coordinates of . In this case, the touch plate 10 may come into contact with other probe needles depending on the positions of the tips a and b. Furthermore, the tip a.

The probe needle may come into contact with other probe needles during the rising process before contacting point b. However, the probe needle 6 is pressed against the semiconductor element for measurement, and the amount of pressing is called overdrive, which is generally 20
An overdrive amount of about 0 μm can be used without deforming or breaking the probe needle, and even if other needles are pushed up, there is no problem within about 200 μm, and it is possible to perform measurements within that range.

Next, a case will be described in which the setting of the energization detector that confirms the contact between the probe needle 6 and the touch plate 1o is performed as in the above (2). The purpose of using the plurality of probe needles 6 arranged on the probe card 7 is to press the semiconductor element formed on the substrate against the bonding pad to establish continuity and test the performance of the semiconductor element. If the height of the probe needles 6 (in the Z direction) is uneven or large, it is conceivable that some of the probe needles may not come into contact with the bonding pad or that poor conduction may occur.

In order to avoid this, extremely high precision is required for variations in the height of the probe needles from the time of manufacturing the probe card 7, and sufficient care must be taken in handling so that the probe needles 6 do not shift in position. For these reasons, the variation in the height (Z direction) of the probe needles 6 with respect to the mounting reference surface of the probe card 7 is very small, and here, the height Z of the plurality of probe needles 6. is considered to be a constant value.

In step 203 of FIG.
If the coordinates of the tip a when it touches the tip a of the probe needle when it rises to point A (XA, yAIZA) are (Xs, ya, Za), then the tip a point is (xa-xA) ' + (ya-3'A)' - to 2(
Za-ZA)" = 0 (k is a constant).

Here, z,=z,=constant, (xi-xA)' + (ya-yA)2= (k(z
n−zA)”...(16) It can be shown as follows.

Similarly, the apex of the conical surface of the touch plate 10 is point B (Xa
, ya+Za ), the coordinates of the tip when it touches the tip of another probe needle are (xb+ylZb)
), then the tip point is (Xb-Xa)2+ (yb-
ya)' = (k(Zn-ZB))'・・・・・・(
17) Exists in

Here, equation (16) is the equation for a circle centered at (XA, yA) with radius l k (z, -zA) I, and equation (17
) is (xa.

This is the equation of a circle with radius l k (z, -za) I centered at ya). This corresponds to at least one of the probe needles 6 arranged on the probe card 7 which is the object to be measured.
This shows that although books exist on each circle, there is no probe needle 6 inside each day. The positions of the plurality of probe needles 6 arranged on the probe card 7 in the XY plane are input into the memory circuit in advance, and the coordinates of the tip n of any one of the probe needles 6 are determined by the formula (16
) is assumed to exist on the circle. Further, the coordinates of the other probe needles are converted by rotationally moving the coordinates of the tip n as a center of rotation, and the rotation angle and the coordinates of the tip n that satisfy the following conditions are determined.

Condition 1: The probe needle exists on the circle of equation (17).

Condition 2: No probe needle exists inside the circle of equation (16).

Condition 3: No probe needle exists inside the circle of equation (17).

Furthermore, the assumed n is successively replaced with other probe needles, and the rotation angle that satisfies the above conditions and the coordinates of the tip of the needle at the center of rotation are determined in the same manner. The solution that satisfies these is 1
In the case of a point, it is the desired position of the probe needle group. In addition, if there are multiple touch plates, move the touch plate 10 eight times, and touch the third touch plate.
Find the circle. Then, a new solution is determined by adding the following conditions to the solution that satisfies the above conditions 1 to 3.

Condition 4: The probe needle exists on the third circle.

Condition 5: No probe needle exists inside the third circle.

Hereafter, the fourth circle, the fifth circle, etc. until the solution reaches one point.
By increasing the conditions, probe card 7
Detect the positions of multiple probe needles placed in the

Although it is assumed here that the height (Z direction) of the multiple probe needles is constant, in reality, it includes variations due to manufacturing errors, etc., which causes a decrease in accuracy in measuring the position of the probe needle 6. It is possible that To avoid this, please follow the above 2. By setting the Z-coordinate of . be. In addition, after measuring with the measurement method that assumes that the heights (in two directions) of the multiple probe needles described above are constant, a probe needle with a characteristic arrangement is selected from the multiple probe needles and the probe needle is It is also possible to perform highly accurate measurements using the measurement method in which there is only one line. Note that a probe needle with the above-mentioned characteristic arrangement is a probe needle located at the upper corner of the probe needle arrangement, or a probe needle where there is no other probe needle near the probe needle and the apex of the conical surface of the touch plate 10 is the probe needle. There are three measurement points near where the touch plate 10 clearly does not come into contact with other probe needles.
Indicates a probe needle that can take more than a point.

However, when the energization detector for confirming the contact between the probe needle 6 and the touch plate 10 is set as described in (2) above, the position of the probe needle may not be detected in some cases. This is the case when the arrangement of the probe needles is point symmetrical. As a specific example, the probe needles 6 may be arranged at the four corners of a square, or they may be arranged in a circle at equal intervals. In these cases, the angle cannot be determined. That is, in a square arrangement, four types of arrangement are possible in the 90° direction. For this reason, with the setting (2) above, the probe cards that can be sewn for measurement are limited. Therefore, in such cases, the above ■ and ■
settings are used.

In the above setting (2), the positions of a plurality of probe needles can be detected by measuring a specific probe needle that outputs an independent detection signal after the measurement in the above-mentioned setting (2). Even in the setting (2) above, detection can be made in the same manner as in the setting (2) above by paying sufficient attention to grouping.

According to this embodiment, the prober is provided with a conical touch plate 10, a mechanism for moving the touch plate 10 up and down, and an energization detector that detects contact between the touch plate 10 and the probe needle 6. It becomes possible to measure the position of the imager 5 shown in FIG.
By combining this with the measurement of the position of the bonding pad on the wafer, it becomes possible to automate the four difficult tasks of aligning the probe needle 6 and the bonding pad while observing with a microscope.

FIG. S is a perspective view showing another embodiment of the touch plate used in the device of FIG. 1. In this figure, 11 is a touch plate whose top surface is a square pyramid, lla is a surface parallel to the Y axis and located in the X direction from the apex among the top four surfaces of touch plate 11, and ttb is the top 4 surface of touch plate 11. Of the surfaces, 11c is a surface parallel to the X axis and existing in the −Y force direction from the apex, and 11c is the
The surface "lid" which is parallel to the axis and exists in the -X direction from the apex is a surface among the four upper surfaces of the touch plate 11 that is parallel to the X axis and exists in the Y direction from the apex.

The touch plate 11 is used for the purpose of measuring the position of the probe needle 6 in place of the conical touch plate 10 shown in FIG. The measuring means is the same as that of the touch plate 10 in FIG. 2, except that the probe needle 6 of the touch plate 10
The equation of the conical surface touching is (x-xo)"+ (Y-
Yo)2+k(z-zo)"=O, whereas the equation of the surface of the square pyramid that contacts the probe needle 6 of the touch plate 11 is four types (four surfaces) of -dimensional equations. The general solution for the plane is ax+by+cz+d=
0, but here, the base of the quadrangular pyramid is a square parallel to the XY-axis plane, the sides of the square are parallel or perpendicular to the The plane parallel to the X axis has the same absolute value of the slope in the two directions with respect to the Y direction, and the plane parallel to the Y axis has the same absolute value of the slope in the Z direction with respect to the X direction. That is, surface 11a in FIG.

The shapes of 11b, 11c, and lid are the same, and the rectangle connecting the four straight lines at the bottom of these four sides is a square, and the X axis,
parallel to the Y axis.

The general solution of the plane is shown as Ax+By+Cz+DwO, but from the above conditions, the surface 11a is Ax+z+D
, wQ. Here, A and ri are constants.

Similarly, the surface ttb is -Ay+z+Db=O (Db is a constant) Similarly, the surface 11c is -A X + z + D e= O (D c is a constant)
Similarly, the surface lid can be expressed as A y + z + D d=O (D d is a constant). Furthermore, since all four faces pass through the vertices, A-D, +Dc-Db-Dd. By making the touch plate a square pyramid in this way, the equation can be simplified and calculation processing can be performed quickly. Although the touch plate has been described in detail here as an example of a square pyramid, the touch plate can also be configured with a triangular pyramid, four or more polygonal pyramids, or even a spherical surface.

6 and 7 are side and perspective views showing still another embodiment of the touch plate used in the device of FIG. 1, where f2a is a first touch plate forming a conical surface with a large apex angle; Plate 12b is a second touch plate forming a conical surface with a small apex angle, and 13 is a base plate that supports the first touch plate 12a and the second touch plate 12b. Then, as in the case of FIG. 1, the first touch plate 12a, the second touch plate 12b, and the base plate 13 are integrally moved by the drive mechanism (not shown) provided on the XY stage of the prober. driven in the direction. That is, this embodiment is characterized in that it has two touch plates, a first touch plate 12a and a second touch plate 12b, instead of the touch plate 10 shown in FIG.

Some probe cards 7 have a sufficiently long distance from the bottom surface of the board to the tip of the probe needle;
Ill II! There are some probe cards.

In this case, if the distance from the apex of the conical surface of the touch plate 10 to the bottom end of the conical surface in FIG. may come into contact with the lower surface of the substrate of the probe card 7. In order to avoid this, it is necessary to reduce the diameter of the conical surface and the circle at the lower end of the touch plate 10 to reduce the overall height. On the other hand, in order to increase the area for one measurement, it is necessary to conversely increase the diameter of the circle at the lower end of the conical surface of the touch plate 10, and in order to satisfy these contradictory requirements, the conical apex angle must be increased. There are possible ways. However, if the apex angle of the cone is increased, a slight error in the height direction becomes a large error in the plane direction. For this purpose, two types of touch plates are prepared, one with a large apex angle and one with a small apex angle.The touch plate with a large apex angle roughly measures the tip position of the probe needle, and the touch plate with a small apex angle performs precise measurements to improve accuracy. Measurement time can be shortened.

[Effects of the Invention] As explained above, according to the present invention, a movable contact member for measuring the position of the probe needle and a means for detecting contact between the contact member and the probe needle are provided in the prober, and the contact member and the probe needle are connected to each other. Since the position of the probe needle is recognized based on the relative position of the contact member and the probe needle when they come into contact with each other, it is possible to automate the positioning of the probe needle and to perform unmanned automatic measurements.

[Brief explanation of the drawing]

1 is a schematic top view of a wafer prober according to an embodiment of the present invention, FIG. 2 is a detailed view of a touch plate used in the apparatus of FIG. 1, and FIG. Figure 2 is a flowchart showing the operation of the device shown in Figure 4. Figure 4 is a schematic diagram of a touch plate equipped with a load cell for detecting the load applied to the touch plate. Figure 5 shows an example of a pyramid-shaped touch plate. The perspective view and Figures 6 and 7 are 2f! ! FIG. 2 is a side view and a perspective view showing an example of a touch plate having a conical surface. 1: Wafer chuck, 2: θZ stage, 3: XY stage, 4: Sensor, 5: Imager, 6: Probe needle, 7:
Probe card, 10° 12a, 12b: touch plate, 11: pyramidal touch plate, 81: load cell element.

Claims (4)

[Claims] (1) In a prober that measures the electrical characteristics of an element formed on a substrate by bringing a probe needle into contact with an electrode of the element, a contact member movable at least in the x and y directions with respect to the probe needle; , a contact detection means for detecting the presence or absence of contact between the contact member and the probe needle, the position of the probe needle based on the relative position of the contact member and the probe needle when the contact member and the probe needle are in contact with each other; A prober characterized by recognizing. (2) The prober according to claim 1, wherein a portion of the contact member that contacts the probe needle has a conical shape. (3) The prober according to claim 1, wherein the contact portion of the contact member with respect to the probe needle is a polygonal pyramid. (4) The prober according to claim 1, wherein the contact member is a plurality of members.