WO2011062312A1

WO2011062312A1 - Wafer prober using a touch pad

Info

Publication number: WO2011062312A1
Application number: PCT/KR2009/006878
Authority: WO
Inventors: 이효선
Original assignee: 주식회사 쎄믹스
Priority date: 2009-11-23
Filing date: 2009-11-23
Publication date: 2011-05-26

Abstract

The present invention relates to a wafer prober for testing a semiconductor device, the wafer prober comprising: a chuck plate for holding a wafer; a touch pad mounted on a top surface of the chuck plate and positioned below the held wafer; a Z-axis base for supporting a Z-axis transfer device that transfers the chuck plate in a Z-axis direction; an XY stage, attached to a bottom surface of the Z-axis base, for transferring the chuck plate along X and Y axes; and a controlling device for receiving a position signal, to be measured by the touch pad, of a probe needle installed on a probe card, and controlling the operation of the Z-axis transfer device and an XY stage transfer device when the probe needle contacts the wafer. When the wafer prober of the present invention is implemented, the contacting point of a probe needle that contacts a wafer can be more accurately measured, the tilt of the chuck plate can be calculated from the distribution of such contacting points to readjust the flatness of the chuck plate and thus enable uniform and precise probing, overdriving can be suitably controlled, and changes in contacting point distribution from overdriving can be measured so as to enable the states of probe needles to be checked.

Description

Wafer Prober with Touchpad

The present invention relates to an apparatus for inspecting electrical characteristics of a semiconductor wafer, and more particularly, to a wafer prober capable of precise and safe probing using a touchpad.

A wafer prober is a device that connects chips on a wafer and a tester. The tester is connected to chips on the wafer through the wafer prober to provide an electrical signal to the chips. By providing and inspecting the results, it is determined whether each of the chips is abnormal or defective.

The configuration and operation of the wafer prober described above will be briefly described with reference to FIG. When the wafer on which the plurality of chips are formed is loaded into the chuck plate 208 by the wafer transfer device 204, the chuck plate 208 is pads of the plurality of chips provided on the wafer by the chuck transfer device 206. A plurality of probes provided in the probe card 210 is moved in the X, Y, and Z directions to align and contact the probes.

When the plurality of probes are in contact with pads of the plurality of chips, respectively, the tester 100 provides a test signal according to a predetermined program to the plurality of chips through a tester connection terminal and a plurality of probes, and the plurality of chips. By providing the output signal according to the test signal to the tester 100, it is possible to perform the electrical characteristic test for each chip.

Here, a mechanical configuration for transferring the chuck plate 208 to the Z-axis will be described with reference to FIG. 2. A lower surface of the chuck plate 208 is provided with a wedge-shaped support 212 cut in a slanted surface. The wedge-shaped Z-axis feeder 216 having a comb surface corresponding to the comb surface of the support 212 is located. A rolling bearing 214 is positioned between the support 212 and the Z-axis feeder 216 to reduce friction.

The Z-axis feeder 216 moves horizontally by a ball screw 218 installed on the bottom surface of the Z-axis feeder 216 and rotated by the Z-axis motor 220. Here, the height of the inclined surface of the support 212 in contact with the Z-axis transfer portion 216 changes as the Z-axis transfer portion 216 moves in the lateral direction. Accordingly, the chuck plate 208 moves in the longitudinal (Z-axis) direction according to the lateral movement of the Z-axis feeder 216.

In addition, the Z-axis base 222 for supporting the bottom surface of the wafer prober is located.

The motor 220 generates a predetermined torque for conveying the Z-axis feeder 216, and may generate excessive torque due to unexpected disturbance. In this case, the chuck feeder may move excessively in the Z-axis to move the chuck plate ( Excessive close contact between the wafer and the probe card mounted on the 208 may damage the probe of the probe card as well as the wafer.

Therefore, in the related art, it has been desired to develop a technology for detecting whether the Z-axis transfer unit 216 is subjected to excessive pressure and stopping Z-axis transfer when excessive pressure is applied. In addition, since the position control of the chuck plate 208 is made very precisely in order to accurately contact the fine pads formed on the wafer and the probes of the probe card 210, the chuck plate 208 is installed with careful consideration of a horizontal state.

However, there is a problem that the inclination of the Z-axis base 222 supporting the Z-axis transfer unit 216 is caused by the unexpected disturbance during use of the wafer prober. Therefore, in the related art, it is desirable to develop a technology capable of detecting the inclination of the Z-axis feeder 216 to correct the inclination of the chuck plate.

In addition, when the probe card is probed onto the wafer, which is the inspection object, the probe needle plane is parallel to the wafer, but in general, the needle plane may not be flat from manufacturing the probe card. Due to the inclination which occurs in driving, it is not possible to contact each other in parallel, and also, a slip phenomenon occurs at the time of contact, which causes a problem that the correct point cannot be contacted.

The problem to solve the above problem is to more accurately measure the contact point of the probe needle in contact with the wafer, calculate the inclination of the chuck plate according to the distribution of the contact point and readjust the parallelism to enable uniform and precise probing, Not only to control the driving properly, but also to provide a device capable of checking the state of the probe needle by measuring a change in the distribution of contact points due to overdriving.

A first aspect of the present invention for solving the above problems is a wafer prober, comprising: a chuck plate for mounting a wafer; A touch pad mounted on an upper surface of the chuck plate and positioned below the seated wafer; Z-axis base for supporting the Z-axis feeder for transferring the chuck plate in the Z-axis direction; An XY stage which is attached to a lower surface of the Z axis base and transfers the chuck plate to the XY axis; And a controller for controlling the driving of the Z-axis feeder and the XY stage feeder by receiving a position signal of the probe needle measured by the touchpad when the probe needle installed in the probe card contacts the wafer.

Here, the touch pad is preferably any one of capacitive, resistive, optical sensor and ultrasonic reflection method, and a pressure sensor is provided below the chuck plate to measure the probing pressure of the probe needle. Is preferred.

In addition, preferably at least three piezoelectric actuators capable of adjusting the inclination of the chuck plate are arranged under the chuck plate, the piezoelectric actuator is tilted by the contact pad of the probe needle measured in the touch pad The measurement may include adjusting the inclination of the chuck plate by receiving a signal from the controller to control the plane of the probe needle and the plane of the chuck plate to be parallel.

In addition, a second aspect of the present invention provides a wafer prober, comprising: a chuck plate for mounting a wafer; A touch pad mounted on an upper surface of the chuck plate and positioned below the seated wafer; Z-axis base for supporting the Z-axis feeder for feeding the chuck plate in the Z-axis direction; An XY stage which is attached to a lower surface of the Z axis base and transfers the chuck plate to the XY axis; A plurality of sensors installed at predetermined positions between the Z-axis base and the XY stage to sense pressure; And storing the sensing values of the plurality of sensors at the initial installation of the wafer prober as initial setting values, and when the probe needle contacts the wafer, the difference between the sensing values from the plurality of sensors and the initial setting values. A control for calculating the external pressure on the Z axis based on the value, and controlling the driving of the Z axis feeder and the XY stage feeder by receiving the calculated external pressure and the position signal of the probe needle measured by the touch pad. Device.

The sensor may be any one of a load cell, a piezo sensor, a strain gauge, and a capacitor sensor, and the touch pad may be any one of a capacitive, resistive, optical sensor, and an ultrasonic reflection method. The plurality of sensors may be installed at four edges between the Z-axis base and the XY stage.

In addition, the plurality of sensors are connected to the support member of the triangular sliding form to the side in the form of a bearing or wedge, and measure the pressure that the vertical downward force is converted into a horizontal force by the piezoelectric element connected to the support member to the outside It is desirable to.

Furthermore, at least three piezoelectric actuators capable of adjusting the inclination of the chuck plate are arranged under the chuck plate, and the piezoelectric actuator measures the tilt of the chuck plate through the contact distribution of the probe needles measured by the touch pad. Preferably, the inclination of the chuck plate is adjusted by receiving a signal from the controller to control the plane of the probe needle and the plane of the chuck plate to be parallel.

By providing the present invention, it is possible to more accurately measure the contact point of the probe needle in contact with the wafer, and to calculate the inclination of the chuck plate and readjust the parallelism according to the distribution of the contact point, to enable uniform and precise probing, The driving can be properly controlled, and the state of the probe needle can be checked by measuring the change of the contact point distribution according to the overdriving.

In addition, the front surface of the wedge-shaped member supports the system, and the precise displacement range of the piezoelectric element can be adjusted according to the size and shape of the structure, thereby compensating the rigidity of the entire system and bringing high precision.

1 is a diagram illustrating a configuration of a conventional wafer prober;

2 is a view illustrating a structure diagram of a conventional wafer prober chuck feeder;

3 is a block diagram illustrating a wafer prober according to the present invention;

4 is a diagram illustrating a plan view of a wafer prober having an actuator for tilt adjustment below the chuck plate according to an embodiment of the present invention;

5 is a view showing the configuration of a wafer prober as still another embodiment according to the present invention;

6 is a view illustrating a configuration of a wafer prober using a wedge member pressure sensor as another embodiment according to the present invention;

FIG. 7 is a diagram illustrating a switching diagram of probing pressure (FIG. 7A) and an arrangement of sensors (FIG. 7B) according to the invention illustrated in FIG. 6.

1: probe card, 5: probe needle, 10: wafer, 20: chuck plate,

23: displacement sensor, 25: actuator, 30: touch pad, 43: shaft, 47: motor,

49: Z axis base, 53: pressure sensor or load cell, 55: XY stage,

500: wedge member pressure sensor, 510: wedge member, 520: piezoelectric element, 530: support

3 is a block diagram illustrating a wafer prober according to the present invention. As shown in Figure 3, the wafer prober according to the present invention includes a chuck plate 20 for seating the wafer; A touch pad 30 mounted on an upper surface of the chuck plate and positioned below the seated wafer 10; Z-axis base 49 for supporting the Z-axis feeder for feeding the chuck plate 20 in the Z-axis direction; An XY stage 55 which is attached to the lower surface of the Z axis base 49 and transfers the chuck plate 20 to the XY axis; And when the probe needle 5 installed on the probe card contacts the wafer 10, receiving the position signal of the probe needle 5 measured by the touch pad 30, and transferring the Z-axis feeder and the XY stage. And a control device 60 for controlling the driving of the device. The Z-axis feeder and the XY stage 55 are represented by the XYZθ driving unit 50 in FIG. 3.

Here, the chuck plate 20 is a support for seating the wafer 10 refers to a wafer 10 support plate that can create a variety of test environments, such as a high temperature environment or a cooling environment during the probe process, the chuck plate 20 The lower part is composed of a transfer device capable of moving the chuck plate 20 up and down, that is, in the Z-axis direction, and a Z-axis base 49 supporting the transfer device. The lower portion of the Z-axis base 49 includes an XY stage capable of driving in the XY direction including the Z axis, and a controller 60 for controlling the driving of the Z-axis feeder and the XY stage feeder. Thus, unlike the general wafer prober configuration, the present invention is equipped with a touch pad 30 on the upper surface of the chuck plate 20, the device for mounting the wafer 10 on the touch pad 30 to perform the probing process It is characterized by.

The touch pad 30 is a kind of touch panel. In general, the touch panel is a computing input device. By touching the buttons displayed on the display, the touch pad 30 can be operated interactively and intuitively, so that anyone can easily operate the computer. This is how you can do it. When a touch panel functioning as an input device is attached to a monitor screen, its structure is called a touch screen, and the structure when the touch panel is used to move a cursor in place of a mouse is called a touch pad 30.

As shown in FIG. 3, the touch pad 30 applied in the present invention is not a general input device such as a touch panel, but is generally used as a measuring device for measuring the contact point of the probe needle 5. It is different from the panel. That is, the general touch panel or the touch pad 30 should use a transparent pad in order to directly contact the display through the transparent conductive film, whereas the touch pad 30 of the present invention accurately measures the position of the contact point regardless of whether it is transparent or not. It just functions as a touch sensor.

Therefore, while the basic configuration of the touch pad 30 will be described below, since the configuration of the transparent conductive film for directly applying to the display may be used as a general conductive film, the term "conductive film" is used instead of the transparent conductive film. The use of such a general conductive film has the advantage of significantly lowering the product cost of the touch pad 30, and also has the advantage of being easily manufactured without the difficulty of manufacturing to maintain transparency as in the conventional touch panel. Of course, it is also possible to use a transparent touch pad 30.

Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings.

The touch pad 30 is fixed to the lower plate on which the conductive film is deposited and the Flim (top plate), and the upper and lower plates of the touched point are contacted to transmit electrical analog X and Y signals to the controller. The general film does not flow electricity, but the film used for the touch pad 30 is a special coating (conductive film) to serve as a conductor. Furthermore, in the present invention, it is also possible to use a conductive film in which conductive films are used instead of a transparent film.

Here, the controller refers to a device for converting the electrical analog signal transmitted from the touch pad 30 into a digital signal and transmitting it to the control driver of each operating system. The driver receives the digital signal from the controller and the touch pad 30 receives the digital signal. Software that is implemented by each operating system. From the driver's point of view, the only thing the controller receives is the coordinates. The coordinates are received by the control device 60 to measure the contact distribution of the probe needles 5 and send the corrected drive signals to the transfer device or the drive unit 50 to control them. Although the control is one device included in the touch pad 30, it may be mounted on the control device 60 of the present invention and used.

In addition, the touch pad 30 applied to the present invention may use various types of touch pads 30, and more preferably, among capacitive, resistive, optical sensors, and ultrasonic reflection methods. It is preferable that it is either. The characteristics are different according to various kinds of the touch pad 30, and thus may be used according to the characteristics in various environments. Resistive film type, ultrasonic reflection type, light sensor type, capacitive type and the like. The resistive film is composed of a structure in which two substrates on which the transparent electrode layer is coated are bonded to each other so that the transparent electrode layers face each other with a dot space therebetween. Since the transparent electrode is coated on the inside of the special film, a signal for position detection is applied when the upper substrate is contacted with a finger or a pen, and an electrical signal is detected to determine the position when it is in contact with the transparent electrode layer of the lower substrate. It has a working principle.

In the ultrasonic reflection method, a piezoelectric element using a piezoelectric effect is used as a transducer for surface wave generation. The piezoelectric element is stretched when a voltage is applied from the outside and a voltage is generated when a deformation is applied from the outside. When contacted, part of the surface wave reflects and returns to the piezoelectric element group to generate voltage. By using this voltage, the piezoelectric element can calculate the time from the generation of the surface wave and the return of the reflected wave. Therefore, by generating surface waves alternately in the X and Y directions, the distance to each input point is determined to determine the position.

In the capacitive method, a transparent electrode is formed by coating a material such as a special conductive metal (TAO) on both sides of the substrate constituting the touch screen sensor, and a certain amount of current flows on the glass surface. Parasitic Capacitance has the principle of detecting the position by calculating the magnitude of the part where the amount of current is changed by using the capacitance in the human body due to the user's touch.

As such, in the present invention, when the touch pad 30 is mounted on the upper surface of the chuck plate on which the wafer 10 is seated, and the wafer 10 is seated and probed, the probe needle 5 is in contact with the wafer 10. It is possible to measure the contact point of the more precise, and to calculate the inclination of the chuck plate 20 according to the distribution of the contact point and readjust the parallelism to enable a uniform and precise probing.

In more detail, as shown in FIG. 3, when the probe needle 5 having a needle plane not parallel to the chuck plate 20 comes into contact with the wafer 10, only a part of the needle comes into contact due to misalignment. In this case, the contact point appears only in certain parts. In order to accurately measure the position of the contact point, in the present invention, the touch pad 30 is mounted on the bottom surface of the wafer 10 to measure the contact point, and the measured signal is sent to the control device 60 to distribute the contact and the chuck plate 20. Calculate the slope of.

Here, the controller 60 sends a control signal to the driver 50 to adjust the inclination of the chuck plate 20 so that the plane of the probe needle 5 and the chuck plate are parallel through the calculated inclination. In addition, since the contact point of the probe needle 5 can be accurately measured, even if a contact point slip occurs due to the probing pressure, a probe signal (i) is sent to a specific point of the wafer 10 for the electrical test by sending a correction signal in the XYZθ direction. 5) can be controlled to make the vertical contact exactly. In addition, when the at least one pressure sensor capable of measuring the probing pressure of the probe needle 5 is provided below the chuck plate 20, it is possible to appropriately control overdriving and to change the distribution of the contact point according to the overdriving. By measuring, the state of the probe needle 5 can be checked.

4 is a diagram illustrating a plan view of a wafer prober in which an actuator 25 for tilt adjustment is installed below the chuck plate 20 as an embodiment according to the present invention. As shown in FIG. 4, the inclination adjustment device includes a control device 60, first to third displacement sensors, ADCs, DACs, first to third actuators 25, and communication modules. The first to third displacement sensors and the first to third actuators 25 are installed between the chuck plate 20 and the base as shown in FIG. 4. The base supports the chuck plate 20 in the vertical direction and is referred to as a Z axis throughout the instruments supporting the vertical direction. In this case, the actuator 25 preferably uses a piezoelectric actuator 25.

The first to third displacement sensors are respectively installed at three equal positions on the rear surface of the chuck plate 20 in contact with the base. The first to third actuators 25 are installed at three equal positions of the rear surface of the chuck plate 20 in contact with the base. When the positions of the first to third displacement sensors and the first to third actuators 25 do not overlap each other, the first to third displacement sensing values of the first to third displacement sensors and the first to third displacement sensors. An initial setting process is required to match the degree of tilt of the chuck plate 20 according to the driving of the three actuators 25.

In addition, each of the first to third displacement sensors senses a vertical gap between the base and the chuck plate 20 at its installation position and provides a sensing signal according to the sensing to the ADC. The ADC converts the first to third sensing signals from the first to third displacement sensors into first to third displacement sensing information and provides them to the control device 60.

The control device 60 may include a first to third displacement sensor in which the first to third displacement sensing information from the first to third displacement sensors are included in the tilt command from the main control device 60. First to third driving commands are generated for each of the first to third actuators 25 to follow the first to third displacement information, respectively.

The first to third drive commands for the first to third actuators 25 are converted into first to third drive signals for the first to third actuators 25 through the DAC and then to the first to third actuators. Are provided at 25. Each of the first to third actuators 25 is disposed between the base and the chuck plate 20 in a vertical direction to a different degree in its installation position according to the first to third driving signals from the control device 60. Push or pull to tilt the chuck plate 20 parallel to the probe card by spacing or adhering the vertical gap between the base and the chuck plate 20.

That is, using the inclination adjusting device having such a configuration, looking at the operation of the entire wafer prober configuration shown in Figure 4, when the Z-axis is driven upward to come into contact with the probe needle (5), the touch pad 30 Measure the contact point of the probe needle (5), and send the measured signal to the control device 60, the control device 60 calculates the contact distribution and thus the inclination of the chuck plate 20 and its correction value, When the corrected signal is sent to the inclination adjusting device, three or more actuators 25 installed under the chuck plate 20 operate to adjust the inclination to be parallel to the probe needle 5 plane.

5 is a view showing the configuration of a wafer prober as still another embodiment according to the present invention. As shown in FIG. 5, the present invention senses the chuck plate 20, the touch pad 30, the Z-axis base 49 for supporting the Z-axis feeder, the XY stage 55 for feeding the XY-axis, and pressure. It comprises a plurality of sensors 53 and a control device 60 for controlling the drive of the Z-axis feeder and XY stage feeder. The Z-axis feeder is preferably configured to include a shaft 43 and a motor 47, but may also be a device for converting horizontal movement to vertical movement using a wedge-shaped member (not shown).

Unlike the invention illustrated in FIGS. 3 and 4, the embodiment of the present invention is an invention in which a plurality of pressure sensors or load cells 53 are provided between the Z-axis base 49 and the XY stage 55. 5) When contacting the wafer 10, measuring load or pressure is an important factor for overdriving control or precise probing. Therefore, in the present invention, when the probe needle 5 contacts, the distribution of the contact point measured by the touch pad 30 is changed according to the load or the pressure, and the measured value may determine the state of the probe needle 5. In addition, there is an advantage that can work safely without damaging the probe needle (5) even in the position correction of the contact point.

The arrangement of the plurality of pressure sensors or load cells 53 should be at least three to know the distribution, and in the case of partial contact, instead of collective contact for inspecting the entire surface of the wafer 10, the partial pressure or load must be accurately measured. It is more preferable to arrange at four edges for measurement. In addition, although the inclination of the chuck plate 20 according to the contact point distribution of the touch pad 30 described above can be known, the inclination of the chuck plate 20 can also be grasped through the pressure distribution or the load distribution by the sensor. Therefore, by measuring the inclination more accurately, it is possible to adjust the parallelism with the probe needle 5 plane to perform a uniform contact.

6 is a view illustrating the configuration of a wafer prober using the wedge member pressure sensor 500 as another embodiment according to the present invention. As shown in FIG. 5, this embodiment includes four sensors 500 between the Z-axis base 49 and the XY stage 55 to measure the downward pressure or load upon contact of the probe needle 5. In the configuration, the downward vertical pressure is characterized by converting the horizontal pressure.

That is, a triangular sliding support member 510 is connected to the side in the form of a bearing or a wedge at four edges between the Z-axis base 49 and the XY stage 55, and the support 530 is horizontal to the member. It is formed in a structure connected to the piezoelectric element 520 fixed to. In this structure, when the chuck plate 20 is subjected to a single load, at least one edge is formed with a vertical downward pressure, and the vertical downward pressure slides the wedge member 510 connected to the bearing in a horizontal direction. Pushed The wedge member 510 is pushed back to the piezoelectric element 520 fixed to the support 530 is a structure that senses the pressure or load.

Such a structure can damage the sensor if the sensor is subjected to the vertical downward force, and the sensor is formed by supporting a certain space in a plurality of places, and the overall rigidity of the test equipment requiring high stability. Although there is a disadvantage in that this weakness, as shown in Figure 6, by using the wedge-shaped member pressure sensor 500 when the vertical downward force is converted into a horizontal force, the front of the wedge-shaped member 210 receives the system In this regard, the precise displacement range of the piezoelectric element 520 can be adjusted according to the size and shape of the structure, thereby bringing high precision.

FIG. 7 is a diagram illustrating a switching schematic diagram of probing pressure (FIG. 7A) and an arrangement structure of a sensor (FIG. 7B) according to the invention illustrated in FIG. 6. As shown in FIG. 7, when the contact load is applied to one of the sensors in the vertical direction, the wedge-shaped member 510 is pushed out to the side by sliding the bearing, and the piezoelectric element fixed to the support 530 connected thereto is connected. 520 is sensed by receiving the pressure converted in the horizontal direction. (FIG. 7A)

In addition, the arrangement of the sensor lies between the Z-axis base 49 and the XY stage 55 and is disposed at four edges, which, as described above, accurately measure not only the batch contact but also the partial contact. To measure the contact distribution more precisely. The wedge member 510 is installed at four edges, and the wedge member 510 is connected to the piezoelectric element 520 fixed to the support 530, thereby sensing the pressure by converting the vertical downward pressure into the horizontal pressure. To form a structure. It is possible to supplement the stiffness and to provide more accurate measurement (Fig. 7 (b)).

While the invention has been shown and described in connection with specific embodiments thereof, it will be understood that various modifications and changes can be made without departing from the spirit and scope of the invention as indicated by the claims. Anyone who owns it can easily find out.

As described above, the present invention more accurately measures the contact point of the probe needle in contact with the wafer, calculate the inclination of the chuck plate according to the distribution of the contact point and readjust the parallelism to enable uniform and precise probing, overdriving In addition, the present invention has industrial applicability in that it is possible to provide a device that can check the state of the probe needle by measuring the change of contact point distribution due to overdriving as well as appropriately.

Claims

In wafer prober,

A chuck plate for seating a wafer;

A touch pad mounted on an upper surface of the chuck plate and positioned below the seated wafer;

Z-axis base for supporting the Z-axis feeder for transferring the chuck plate in the Z-axis direction;

An XY stage which is attached to a lower surface of the Z axis base and transfers the chuck plate to the XY axis; And

And a control device for controlling the driving of the Z-axis feeder and the XY stage feeder by receiving a position signal of the probe needle measured by the touch pad when the probe needle installed on the probe card contacts the wafer. Wafer prober.
The method of claim 1,

The touch pad is a wafer prober, characterized in that any one of capacitive, resistive, optical sensor and ultrasonic reflection method.
The method of claim 1,

And a pressure sensor or a load cell for measuring the probing pressure of the probe needle under the chuck plate.
The method of claim 1,

At least three piezoelectric actuators capable of adjusting the inclination of the chuck plate are arranged under the chuck plate, and the piezoelectric actuator measures the tilt of the chuck plate through the contact distribution of the probe needles measured by the touchpad, And a signal for controlling the plane of the needle and the plane of the chuck plate to be parallel to the wafer prober, wherein the inclination of the chuck plate is adjusted.
In wafer prober,

A chuck plate for seating a wafer;

A touch pad mounted on an upper surface of the chuck plate and positioned below the seated wafer;

Z-axis base for supporting the Z-axis feeder for transferring the chuck plate in the Z-axis direction;

An XY stage which is attached to a lower surface of the Z axis base and transfers the chuck plate to the XY axis;

A plurality of sensors installed at predetermined positions between the Z-axis base and the XY stage to sense pressure;

Initially set the sensing values of the plurality of sensors when the wafer prober is initially installed.

When the probe needle contacts the wafer when the probe needle contacts the wafer, an external pressure on the Z axis is calculated based on a difference between the sensing values from the plurality of sensors and the initial set value, and the calculated external pressure And a controller for receiving the position signal of the probe needle measured by the touch pad to control driving of the Z axis feeder and the XY stage feeder.
The method of claim 5,

The sensor is a wafer prober, characterized in that any one of the load cell, piezo sensor, strain gauge and capacitor sensor.
The method of claim 5,

And the plurality of sensors are installed at four edges between the Z axis base and the XY stage.
The method of claim 7, wherein

The plurality of sensors are connected to the support member of the triangular sliding form to the side in the form of a bearing or wedge, and measuring the pressure that the vertical downward force is converted into a horizontal force by the piezoelectric element connected to the support member to the outside Wafer prober characterized by the above-mentioned.
The method of claim 5,

The touch pad is a wafer prober, characterized in that any one of capacitive, resistive, optical sensor and ultrasonic reflection method.
The method according to any one of claims 6 to 9,

At least three piezoelectric actuators capable of adjusting the inclination of the chuck plate are arranged under the chuck plate, and the piezoelectric actuator measures the tilt of the chuck plate through the contact distribution of the probe needles measured by the touchpad, And a signal for controlling the plane of the needle and the plane of the chuck plate to be parallel to the wafer prober, wherein the inclination of the chuck plate is adjusted.