JP4878919B2 - Prober and probing method - Google Patents

Description

  The present invention relates to a prober and a probing method for connecting an electrode of an electronic device to a tester in order to perform electrical inspection of a plurality of electronic devices such as a semiconductor chip (die) formed on a substrate such as a semiconductor wafer and MEMS. . Hereinafter, a case where an electronic device (semiconductor chip) formed on a semiconductor wafer is inspected will be described as an example. However, the present invention is not limited to this, and the MEMS or glass substrate formed on the substrate is not limited thereto. The present invention can also be applied to a prober and a probing method for performing electrical inspection of an electronic device or the like on the formed liquid crystal panel.

  In the semiconductor manufacturing process, various processes are performed on a thin disk-shaped semiconductor wafer to form a plurality of chips (dies) each having an electronic device. Each chip is inspected for electrical characteristics, then separated by a dicer, and then fixed to a lead frame and assembled. The inspection of the electrical characteristics is performed using a prober and a tester. The prober fixes the wafer to the stage and brings the probe into contact with the electrode pad of each chip. The tester supplies power and various test signals from the terminals connected to the probe, and analyzes the signals output to the electrodes of the chip with the tester to check whether it operates normally.

  Electronic devices are used in a wide range of applications and are used in a wide temperature range. Therefore, when inspecting an electronic device, it is necessary to inspect at room temperature (room temperature), a high temperature such as 200 ° C., and a low temperature such as −55 ° C. It is required that the inspection can be performed. Therefore, a wafer temperature adjustment mechanism that changes the temperature of the surface of the stage, such as a heater mechanism, a chiller mechanism, or a heat pump mechanism, is provided below the wafer mounting surface of the stage that holds the wafer in the prober, and is held on the stage. The heated wafer is heated or cooled.

  FIG. 1 is a diagram showing a schematic configuration of a wafer test system including a prober having a wafer temperature adjusting mechanism. As shown, the prober 10 includes a base 11, a moving base 12, a Y-axis moving unit 13, an X-axis moving unit 14, a Z-axis moving unit 15, and a Z-axis moving table provided thereon. 16, θ rotation unit 17, stage 18, needle alignment camera 19 for detecting the position of the probe, support columns 20 and 21, head stage 22, and wafer alignment camera 23 provided on a support column (not shown). A card holder 24 provided on the head stage 22, a probe card 25 attached to the card holder 24, and a stage movement control unit 27. The probe card 25 is provided with a probe 26 such as a cantilever or a spring pin. The movement base 12, the Y-axis movement unit 13, the X-axis movement unit 14, the Z-axis movement unit 15, the Z-axis movement table 16, and the θ rotation unit 17 move the stage 18 around the three axes and around the Z axis. The moving / rotating mechanism is configured to rotate and is controlled by the stage movement control unit 27. Since the moving / rotating mechanism is widely known, the description thereof is omitted here. The probe card 25 has a probe 26 arranged according to the electrode arrangement of the device to be inspected, and is exchanged according to the device to be inspected.

  In the stage 18, a heater / cooling liquid path 28 is provided to make the stage 18 hot or cold. The temperature control unit 29 controls the electric power supplied to the heater of the heater / cooling liquid path 28 and the temperature of the cooling liquid circulated in the cooling liquid path. Thereby, the stage 18 can be set to a desired temperature between high temperature and low temperature, and the wafer W held on the stage 18 can be inspected at a desired temperature accordingly. The temperature control unit 29 performs control based on the temperature detected by a temperature sensor (not shown) provided near the surface of the stage 18.

  The tester 30 includes a tester body 31 and a contact ring 32 provided on the tester body 31. The probe card 25 is provided with a terminal connected to each probe, and the contact ring 32 has a spring probe arranged so as to contact the terminal. The tester body 31 is held with respect to the prober 10 by a support mechanism (not shown).

  When the inspection is performed, the Z-axis moving table 16 is moved so that the needle alignment camera 19 is positioned below the probe 26, and the tip position of the probe 26 is detected by the needle alignment camera 19. The detection of the tip position of the probe 26 must be performed whenever the probe card is replaced, and is appropriately performed every time a predetermined number of chips are measured even when the probe card is not replaced. Next, with the wafer W to be inspected held on the stage 18, the Z-axis moving table 16 is moved so that the wafer W is positioned under the wafer alignment camera 23, and the electrode pads of the electronic devices on the wafer W are moved. Detect position. It is not necessary to detect the positions of all the electrode pads of one chip, and the positions of several electrode pads may be detected. Further, it is not necessary to detect the electrode pads of all the chips on the wafer W, and the positions of the electrode pads of several chips are detected. The relative position between the needle alignment camera 19 and the wafer alignment camera 23 is such that the needle alignment camera 19 detects the tip position of the probe 26 and the wafer alignment camera 23 detects the trace of the needle brought into contact with the electrode. Measured in advance.

  FIG. 2 is a diagram for explaining the operation of bringing the electrode pad into contact with the probe 26. After detecting the position of the probe 26 and the position of the wafer W, the stage 18 is rotated by the θ rotation unit 17 so that the arrangement direction of the electrode pads of the chip matches the arrangement direction of the probe 26. Then, after moving so that the electrode pad of the chip to be inspected on the wafer W is positioned below the probe 26, the stage 18 is raised and the electrode pad is brought into contact with the probe 26.

  The probe 26 has a spring characteristic and contacts the electrode with a predetermined contact pressure by raising the contact point from the tip position of the probe. In consideration of the inclination of the wafer W and the arrangement surface of the tip of the probe 26 and the variation of the tip position of the probe 26, the electrode pad and the probe 26 are placed up to a position higher than the tip position of the probe 26 so that the electrode 26 and the probe 26 come into contact with each other. The surface of the pad, that is, the wafer W is raised. This is referred to as overdrive, and the amount of movement that further raises the surface of the wafer W from the detected tip position of the probe 26 is referred to as overdrive amount. Therefore, if all the probes are in contact with the electrodes of the wafer at a predetermined contact pressure, the entire stage 18 is subjected to a contact pressure obtained by multiplying the contact pressure of one probe by the number of probes. In recent years, in order to improve throughput, multi-probing processing for inspecting a plurality of dies simultaneously has been performed, and the number of probes may be several thousand. In such a case, the probe card 25 and A very large contact pressure is applied to the stage 18 as a whole.

  The variation of the probe tip position is set to be within a predetermined range, which is confirmed by the needle alignment camera 19, and the probe card is repaired when there is a probe whose tip position is outside the predetermined range. . As described above, since the tip position of the probe is within the predetermined range, when the electrode of the electronic device is brought into contact with the probe as described above, the wafer is further lifted from the contact position by the overdrive amount, thereby It has been considered that the contact pressure with the electrode falls within a predetermined range.

  However, with the miniaturization and high integration of electronic devices, the electrode portions are also becoming smaller, and high-precision alignment accuracy and high-precision movement control are required. Furthermore, the film thickness of the electrode portion tends to be thin, and the allowable range of contact pressure is also small. In particular, when an inspection is performed at a high temperature or a low temperature, there is a problem that the temperature of each part changes and an error occurs in the moving amount of the moving mechanism.

  Therefore, Patent Document 1 captures an image of the probe 26 when the needle alignment camera 19 provided close to the stage 18 passes under the probe 26, detects the position of the probe 26, and changes the position of the probe 26. It describes detecting and correcting.

  Patent Document 2 describes that at least one of the temperature of the probe card and the contact pressure of the probe card is detected, and the position of the stage is corrected based on the detected value. The pressure is detected using a pressure sensor.

  Patent Document 3 provides a pressure sensor that measures the load on the stage, measures the load generated by the contact between the probe and the wafer, and controls the amount of overdrive. In other words, the contact pressure to the electrodes of the entire probe is constant. It is described that.

  Further, Patent Document 4 provides a linear encoder that detects the position of the stage, and calculates the contact pressure by calculating the amount of sinking due to contact of the probe with the wafer from the difference between the overdrive amount and the actual displacement amount. It is described.

JP-A-10-199942 JP-A-11-176893 JP2001-110857 JP 2001-228212 A

  As described above, the contact between the probe and the electrode of the electronic device is performed based on the relative position between the probe and the electrode detected by the alignment operation. However, if the stage 18 is moved to inspect the wafer W at a high temperature or a low temperature, the temperature of the mounting portion of the wafer alignment camera 23 and the moving mechanism of the stage changes and expands and contracts. When this occurs and moves based on the value determined by the alignment operation, there is a problem that the electrode cannot be brought into contact with the probe correctly.

  In order to solve such problems, it is possible to wait until the temperature condition to be inspected is stable and perform the alignment operation in a stable state, but it is necessary to wait until the temperature condition is stable, and the throughput is reduced. Problem occurs.

  The prober also uses a test wafer, finds the relationship of changes in the relative distance between the probe and the electrode for each temperature condition, and determines the time interval for performing the alignment operation based on the result. However, although the realignment operation was performed according to the determined time interval, the prober's device operation rate decreased more than necessary, resulting in a deterioration in throughput and a further increase in complicated work for realignment. It was.

  As described above, the cited documents 2-4 describe that the contact pressure between the probe and the electrode is detected and controlled so as to be within a predetermined range, but no realignment operation is described. . The effect of temperature change affects not only the change in contact pressure between the probe and electrode, that is, the position error in the direction perpendicular to the stage mounting surface (Z-axis direction) but also in other directions. However, the cited documents 2-4 do not describe such a problem at all.

  An object of the present invention is to realize a prober and a probing method capable of appropriately determining that realignment is necessary due to a temperature change or the like, and always maintaining an appropriate probe-electrode contact state without reducing throughput. To do.

  In order to achieve the above object, the prober and the probing method of the present invention measure the load applied to the stage and activate the realignment operation when the measured load exceeds a predetermined range.

  That is, the prober of the present invention is a prober for connecting each terminal of the tester to the electrode of the electronic device in order to inspect the electronic device on the substrate with a tester, and is in contact with the electrode of the electronic device. A probe card having a probe for connecting the electrode to a terminal of the tester, a stage for holding a substrate, a moving mechanism for moving the stage, a movement control unit for controlling the moving mechanism, and the probe of the probe card An alignment mechanism that detects the relative position between the electrode of the electronic device and the probe by performing an alignment operation of detecting the position of the electrode of the electronic device on the substrate held on the stage. The movement control unit inspects based on the relative position detected by the alignment mechanism In a prober that controls the moving mechanism so that the electrode of the child device is in contact with the probe, a stage load measuring unit that measures a load applied to the stage, and when the measured load is outside a predetermined range, the alignment mechanism Realignment starting means for starting the alignment operation.

  Further, in the probing method of the present invention, in order to inspect an electronic device on a substrate with a tester, the substrate is provided on a probe card of a prober and probes connected to the terminals of the tester are held on the stage. A probing method for contacting an electrode of an upper electronic device, comprising: an alignment operation for detecting the position of the probe of the probe card and detecting the position of the electrode of the electronic device on the wafer held on the stage In the probing method, the relative position between the electrode of the electronic device and the probe is detected, and the electrode of the electronic device to be inspected is moved so as to contact the probe based on the detected relative position. When such a load is measured and the measured load is outside the predetermined range, Restart the alignment operation by Imento mechanism, characterized in that.

  FIG. 3 is a flowchart showing the basic configuration of the prober and probing method of the present invention. As shown in FIG. 3, according to the present invention, an alignment operation is performed in step 101, and an operation of contacting the probe and the electrode is performed in step 102 based on the result of the alignment operation. The above operation is the same as the probing operation in the conventional general prober. According to the configuration described in Patent Document 2-4 described above, an operation of measuring the stage load is further performed in Step 103, and it is determined whether the load measured in Step 104 is within a predetermined range. If it is within the range, the process returns to step 103, the inspection operation is started, and steps 103 and 104 are repeated during the inspection. And according to the structure described in patent documents 2-4, when it is out of the range, feedback control is performed to move the stage in the Z-axis direction by the moving mechanism so as to be within the range.

  On the other hand, in the present invention, when it is determined that the load measured in step 104 is outside the predetermined range, the process returns to step 101 and the alignment operation is started again. If the measured load falls outside the predetermined range, it is considered that a large displacement necessary for the realignment operation has occurred due to a temperature change or the like. In such a case, the alignment operation is started.

  Various directions can be considered for the load to be measured, but it is desirable to measure at least the Z-axis direction perpendicular to the stage mounting surface. The contact pressure generated when the probe contacts the electrode on the substrate is mainly generated in the Z-axis direction. However, depending on the shape of the probe and the position on the substrate that the probe contacts, a load other than the Z-axis direction is generated. It is conceivable to measure not only the direction but also other directions, for example, the X and Y directions perpendicular to the Z-axis direction, and rotational (θ rotation) loads around the Z-axis. However, when the generation of a load other than in the Z-axis direction is smaller than that in the Z-axis direction, only the load in the Z-axis direction may be measured.

  The load in the Z-axis direction can be measured, for example, by providing a pressure sensor at the stage support portion described in Patent Document 3.

  When a linear motor, DC servo motor, or AC servo motor is used as the drive motor for the moving mechanism, when control is performed to maintain the position based on the encoder and scale values, the load applied to the motor shaft It is proportional, and the load can be calculated from the measured motor current. The motor current can be measured with a simple circuit. If this configuration is used, the load on the X axis, the Y axis, and the θ rotation axis other than the Z axis can be measured at a low cost.

  The load is measured when the electrode is brought into contact with the probe and also in a state where an inspection operation is being performed. When it is detected that the load exceeds a predetermined range during the inspection, the realignment operation is activated when the inspection of the electronic device brought into contact with the probe is completed. The realignment operation may be activated automatically or may be performed in accordance with an instruction from the operator by notifying the operator that the measured load is outside the predetermined range.

  According to the present invention, since the load change is monitored, it is appropriately determined that the realignment is necessary based on the load change, and the realignment operation is started. The contact state can always be maintained in an appropriate state.

  The prober according to the embodiment of the present invention is used in the wafer test system shown in FIG.

  FIG. 4 is a diagram illustrating a configuration of a portion related to the stage 18 of the prober and its moving mechanism of the embodiment. As shown in FIG. 3, a probe 26 is provided on a probe card 25 held by a card holder (not shown) so as to face a wafer W held on a stage 18. As shown in FIG. 1, the stage 18 is provided with a heater / cooling liquid passage 28, but the illustration is omitted. The stage 18 is supported by the θ rotation unit 17 and is rotatable around the Z axis. The θ rotation unit 17 and the needle alignment camera 19 are supported by the Z-axis moving table 16 and can be moved in the Z-axis direction (vertical direction) by the Z-axis moving unit 15.

  The Z-axis moving unit 15 is attached to a sliding member 41 supported so as to be slidable in the Z-axis direction with respect to the sliding base 42 provided on the X-axis moving table 47. A ball screw nut 44 is attached to the bottom plate 43 of the sliding member 41. The ball screw 45 is supported by a bearing (not shown) of the Z-axis moving table 16 and a bearing 46 of the X-axis moving table 47 and is rotated by a Z-axis motor 48 provided on the X-axis moving table 47. When the ball screw 45 rotates, the Z-axis moving table 16 moves in the Z-axis direction according to the rotation direction.

  In the X-axis moving unit 14, two side plates 50 and a sliding base 51 are provided on the Y moving table 58. The sliding member 52 provided below the X-axis moving table 47 is supported so as to be slidable in the X-axis direction with respect to the sliding base 51, and the X-axis moving table 47 is movable in the X-axis direction. . Ball screws 55 are supported on bearings 56 (only one shown) of the two side plates 50 and are rotated by an X-axis motor 57 provided on the side plates 50. A support plate 53 is provided below the X-axis moving table 47, and a nut portion 54 of a ball screw 55 is attached to the support plate 53. When the ball screw 55 rotates, the X-axis moving table 47 moves in the X-axis direction according to the rotation direction.

  Furthermore, a Z-axis motor drive unit 61 that drives the Z-axis motor 48 and an X-axis motor drive unit 64 that drives the X-axis motor 57 are provided.

  Here, only the Z-axis moving mechanism and the X-axis moving mechanism are shown, but the Y-axis moving unit 13 is also provided with a similar mechanism, and the θ rotating unit 17 is provided with a stage 18 around the Z-axis by a motor. A rotating mechanism is provided, and a drive unit for driving each drive motor is provided. The above configuration is the same as the conventional example.

  In this embodiment, the drive motors 48 and 57 are linear motors. In the linear motor, since the motor load corresponds to the current value, that is, the torque and the current value, the motor load can be measured by measuring the current value. As described above, a motor corresponding to a torque and a current value, for example, a DC servo motor or an AC servo motor can be used instead of the linear motor. Therefore, a stepping motor whose torque and current value do not correspond cannot be used.

  Each drive motor is provided with an encoder so that the amount of rotation can be controlled. Further, a linear scale is provided for each of the X axis, the Y axis, and the Z axis, and the position can be controlled by reading the value of the linear scale. Note that the rotation amount of the θ rotation axis can be controlled by providing a scale for detecting the rotation amount.

  In this embodiment, there is provided a calculation unit that measures the currents of the drive motors of the Z axis, the X axis, the Y axis, and the θ rotation axis, and calculates a load from the measured values. As shown in FIG. 4, a Z-axis current measurement unit 62 that measures the current of the drive signal of the Z-axis motor 48 in the Z-axis motor drive unit 61, a current-load calculation unit 63 that calculates a load from the measured current, An X-axis current measurement unit 65 that measures the current of the drive signal of the X-axis motor 57 in the X-axis motor drive unit 64 and a current-load calculation unit 66 that calculates a load from the measured current are provided. The Z-axis and X-axis load data calculated by the current-load calculation units 63 and 66 are sent to the control unit 70. The control unit 70 controls the entire prober, has the stage movement control unit 27 of FIG. 1, and is realized by a computer. Moreover, the display part 71 is provided and the display with respect to an operator can be performed from the control part 70. FIG. Although only the portion for calculating the loads on the Z axis and the X axis is shown here, a current measuring unit and a current-load calculating unit are also provided for the Y axis and the θ rotation axis.

  FIG. 5 shows a control operation of the control unit 70 in the prober of the embodiment, in which the electrode of the semiconductor chip to be inspected on the wafer is brought into contact with the probe, the load of each axis is measured, and the realignment operation is started as necessary. It is a flowchart.

  In step 201, an alignment operation is performed to detect the relative position between the electrode of the semiconductor chip to be inspected and the probe 26.

  In step 202, based on the result of the alignment operation, the X axis, the Y axis, and the θ rotation movement mechanism are controlled to move the stage so that the electrode is positioned under the probe. The movement amount is controlled using an encoder and a linear scale.

  In step 203, the X-axis, Y-axis, and θ rotation drive motors are switched to the holding mode. In the holding mode, an operation for maintaining the moved position is performed, and the linear scale or the like is monitored, and control is performed so that the moved position, that is, the scale value does not change.

  In step 204, the Z-axis drive motor is controlled to move the stage so that a predetermined overdrive amount is obtained.

  In step 205, the Z-axis drive motor is switched to the holding mode. As described above, the stage is moved in the Z-axis direction so as to have a predetermined overdrive amount, and since the probe is bent in contact with the electrode, contact pressure is generated, and the position in the Z-axis direction is In order to maintain it, it is necessary to generate a certain amount of torque, and it is necessary to pass a current through the Z-axis motor.

  In step 206, the current value of the Z-axis drive motor is measured.

  In step 207, the Z-axis load is calculated from the measured current value. The Z-axis load calculated here corresponds to the contact pressure with the electrode of the probe.

  In step 208, it is determined whether the calculated load is within a predetermined range set in advance.

  If it is out of the range, the process proceeds to step 218, and if it is within the range, the process proceeds to step 209.

  In step 209, the current value of the X-axis drive motor is measured.

  In step 210, the X-axis load is calculated from the measured current value.

  In step 211, it is determined whether the calculated load in the X-axis direction is within a predetermined range set in advance.

  If it is out of the range, the process proceeds to step 218, and if it is within the range, the process proceeds to step 212.

  In step 212, the current value of the Y-axis drive motor is measured.

  In step 213, the Y-axis load is calculated from the measured current value.

  In step 214, it is determined whether the calculated load in the Y-axis direction is within a predetermined range set in advance.

  If it is out of the range, the process proceeds to step 218, and if it is within the range, the process proceeds to step 215.

  In step 215, the current value of the drive motor of the θ rotation shaft is measured.

  In step 216, the load on the θ rotation axis is calculated from the measured current value.

  In step 217, it is determined whether or not the calculated load in the θ rotation axis direction is within a predetermined range set in advance.

  If it is out of the range, the process proceeds to step 218, and if it is within the range, the process returns to step 206. When the process returns to step 206, it means that all the loads on the respective axes are normal, and the inspection is started. Then, steps 206 to 217 are repeated during the inspection to monitor whether the load exceeds a predetermined range.

  In step 218, information on the load exceeding the predetermined range, information on an axis exceeding the predetermined range, and the like are displayed, and if the realignment operation is to be performed immediately to the operator, a display is given to instruct, and the process proceeds to step 219. .

  In step 219, it is determined whether inspection is in progress. Here, even if the load exceeds a predetermined range, the inspection is not interrupted and the realignment operation is not performed immediately, and the realignment operation is performed after the inspection is completed. If the inspection is not in progress, the process returns to step 201 to perform the alignment operation again. If the inspection is in progress, the process returns to step 218 to display a warning. Instead of returning to step 218, the process may return to step 206. Thereby, the further change of a load can be monitored.

  As described above, it goes without saying that various modifications of the embodiments of the present invention are possible. For example, in the embodiment, the loads on the Z-axis, X-axis, Y-axis, and θ-rotation axis are measured and monitored to see whether they are within the range. When the change is small enough to be ignored and the influence on the position error is small, the load may be measured and monitored only for the Z axis.

  In the embodiment, the load value is calculated by measuring the current value of the drive motor. However, the load can be measured by other methods. For example, as described in Patent Document 3, it is possible to measure the load in the Z-axis direction with a pressure sensor provided in a portion that supports the stage. However, the pressure sensor is more expensive than the current measurement circuit, and it is difficult to provide the pressure sensor while maintaining the rigidity of the stage, and the installation mechanism is complicated.

  Further, in the embodiment, even if the load exceeds a predetermined range during the inspection, it waits until the inspection of the electronic device in which the probe is in contact with the electrode is completed, and the realignment operation is performed when the operator gives an instruction. For example, the realignment operation may be performed immediately after the load exceeds a predetermined range, or the realignment operation may be performed after the inspection of all the electronic devices on the wafer being inspected is completed.

  The present invention is applicable to any prober as long as it is a prober.

It is a figure which shows the basic composition of the system which test | inspects the chip | tip on a wafer with a prober and a tester. It is a figure explaining the operation | movement which makes an electrode pad contact a probe. It is a flowchart which shows the basic composition of the prober and probing method of this invention. It is a figure which shows the structure of the part relevant to the stage of the prober of the Example of this invention, and its moving mechanism. 6 is a flowchart showing a control operation in which the probe of the embodiment brings the electrode of the semiconductor chip into contact with the probe and maintains the contact state during the inspection.

Explanation of symbols

13 Y-axis moving unit 14 X-axis moving unit 15 Z-axis moving unit 16 Z-axis moving unit 17 θ rotating unit 18 Stage 19 Needle alignment camera 23 Wafer alignment camera 25 Probe card 26 Probe 27 Stage movement control unit 48 Z-axis motor 57 X-axis motor 61 Z-axis motor drive unit 62 Z-axis current measurement unit 63, 66 Current-load calculation unit 64 X-axis motor drive unit 65 X-axis current measurement unit 70 Control unit W Wafer

Claims (12)

A prober for connecting each terminal of the tester to an electrode of the electronic device in order to inspect the electronic device on the substrate with a tester,
A probe card having a probe that contacts an electrode of the electronic device and connects the electrode to a terminal of the tester;
A stage for holding a substrate;
A moving mechanism for moving the stage;
A movement control unit for controlling the movement mechanism;
The position of the probe on the probe card is detected, and an alignment operation for detecting the position of the electrode of the electronic device on the substrate held on the stage is performed to detect the relative position of the electrode of the electronic device and the probe An alignment mechanism
The movement control unit is a prober that controls the movement mechanism to bring the electrode of the electronic device to be inspected into contact with the probe based on the relative position detected by the alignment mechanism.
Stage load measuring means for measuring the load applied to the stage;
A prober, comprising: a re-alignment starting unit that starts an alignment operation by the alignment mechanism when the measured load is outside a predetermined range. The stage load measuring means includes
A motor current measuring unit for measuring a current value of a driving motor of at least one moving shaft of the moving mechanism;
The load applied to the at least one moving shaft of the moving mechanism is determined from the current value measured by the motor current measuring unit when the movement control unit controls the moving position of the at least one moving shaft to be maintained. The prober according to claim 1, further comprising: a current-load calculation unit that performs calculation.   The prober according to claim 2, wherein the drive motor is any one of a linear motor, a DC servo motor, and an AC servo motor. The stage load measuring means includes
The prober according to claim 1, wherein the prober is a pressure sensor provided at a portion that supports the stage, and measures a load in a direction perpendicular to a substrate placement surface of the stage.   5. The prober according to claim 1, wherein the realignment activation unit activates an alignment operation by the alignment mechanism when inspection of the electronic device brought into contact with the probe in contact with an electrode is completed.   The prober according to any one of claims 1 to 5, further comprising warning means for notifying that the measured load is outside a predetermined range. In order to inspect an electronic device on a substrate with a tester, a probe provided on a probe card of a prober and connected to each terminal of the tester is brought into contact with an electrode of the electronic device on the substrate held on the stage. A probing method,
The position of the probe on the probe card is detected, and an alignment operation for detecting the position of the electrode of the electronic device on the substrate held on the stage is performed to detect the relative position of the electrode of the electronic device and the probe And
In the probing method of moving the electrode of the electronic device to be inspected so as to contact the probe based on the detected relative position,
Measure the load on the stage,
A prober, wherein when the measured load is outside a predetermined range, the alignment operation by the alignment mechanism is restarted. The load is
Measuring the current value of the drive motor when the drive motor of at least one moving shaft of the moving mechanism for moving the stage is controlled to maintain the moving position;
The probing method according to claim 7, wherein the probing method is obtained by calculating a load applied to the at least one moving axis of the moving mechanism from the measured current value.   The probing method according to claim 8, wherein the drive motor is any one of a linear motor, a DC servo motor, and an AC servo motor. The load is
The probing method according to claim 7, wherein the probing method is a load in a direction perpendicular to a substrate mounting surface of the stage, which is measured by a pressure sensor provided in a portion supporting the stage.   11. The probing method according to claim 7, wherein the restart of the alignment operation is performed when inspection of the electronic device in which an electrode is brought into contact with the probe is completed.   12. The probing method according to claim 7, wherein when the measured load is outside the predetermined range, it is notified that the load is outside the predetermined range.

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