JP6267546B2 - Contact position control method - Google Patents

Description

  The present invention relates to a contact position control method, and in particular, an optimum probe for contacting an object such as a semiconductor wafer with a probe provided on a probe card and inspecting the electric characteristics of the object. Contact position control method for obtaining a contact position between a probe and a cleaning material that is most suitable for cleaning the probe by contacting a cleaning material with a probe provided on a probe card or a contact position with a subject It is about.

  In the semiconductor manufacturing process, various processes are performed on a thin disk-shaped semiconductor wafer to form a plurality of chips (die) 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 generally performed using a probe card (prober) and a tester (see, for example, Patent Document 1 and Patent Document 2).

  In the electrical characteristic inspection known from Patent Document 1 and Patent Document 2, the semiconductor wafer is fixed on the stage, the prober is fixed above the stage, and the electrode pads of each chip are raised together with the stage to probe. Touch the card. The tester supplies power and various test signals to the probe terminals, acquires signals output to the electrodes of each chip, analyzes them with the tester, and confirms whether they are operating normally.

  As described above, in the inspection in which the probe and the semiconductor wafer are brought into contact with each other to check the electrical characteristics, the semiconductor wafer is always moved to a predetermined position in order to optimize the contact (contact). A method of managing the optimum movement amount is adopted so that contact is made. Further, in order to obtain the optimum value of the movement amount, various corrections are performed in consideration of the influence of variations and deformations of parts constituting the inspection apparatus.

  Further, in the method of inspecting electrical characteristics by bringing the electrode pad of each chip in the semiconductor wafer into contact with the probe as described above, if the contact surface (contact surface) of the probe contacting the electrode pad of each chip is dirty Since there is a possibility that an accurate test is not performed, the contact surface of the probe is periodically cleaned. In the cleaning operation, for example, a sheet-shaped cleaning material is fixed on the stage and the probe card is fixed and arranged above the stage. In this state, the cleaning material is raised together with the stage and brought into contact with the probe. The contact surface is being cleaned.

Japanese Patent No. 4878919 Japanese Patent No. 5221118

  However, in the inspection of the electrical characteristics of an electronic device, in order to bring the semiconductor wafer into contact with the probe, the method for managing the optimum amount of movement of the semiconductor wafer is not suitable for the heat generated by deformation or temperature change during contact between the semiconductor wafer and the probe. In order to create an optimal contact state due to the influence of deformation or the like, it is necessary to repeatedly measure and correct the displacement amount many times.

Therefore, a mechanism for controlling the motor current and torque of the target shaft (hereinafter collectively referred to as “motor current”) is being studied as means for changing the correction of the movement amount. However, when controlling the motor current, in addition to the contact load, there are force components (frictional force when driving the stage, weight of the stage itself, etc.) that affect driving of the target shaft. For this reason, even if the contact load is the same, the measured value of the motor current differs depending on the behavior of the shaft, for example, at rest and during operation. Further, when feedback control is performed using the measured motor current value, it is necessary to perform a correction operation before or during the test of the semiconductor wafer in order to obtain a correct contact load. However, the correction operation changes the contact state between the semiconductor wafer and the probe card each time, and there is a high possibility that the test result will be affected by the change in the contact resistance value.

  That is, the force that affects the measurement of the motor current value includes a force component (frictional force, weight, etc.) that affects the driving of the target shaft in addition to the contact load. For this reason, the measured value varies depending on the behavior of the shaft even with the same contact load. Therefore, in order to obtain an appropriate contact load, a complicated calculation for removing other components is required, resulting in a problem that the system becomes complicated.

  Also, in the probe cleaning operation, as with the electrical property inspection, in order to create an optimal contact state for bringing the cleaning material into contact with the probe, the measurement and correction of the displacement amount are similarly repeated to perform a complicated calculation. There is a problem that the system becomes complicated.

  Therefore, an object of the present invention is to provide a contact position control method capable of obtaining an appropriate contact load between a probe and a subject without performing complicated calculations in the electrical property inspection of the subject.

  In addition, the present invention provides a contact position control method capable of improving the cleaning accuracy with respect to the probe by making the contact load between the probe and the cleaning material constant.

The present invention has been proposed in order to achieve the above object, and the invention according to claim 1 is directed to contacting a subject placed on a mounting table with a probe provided on a probe card, and In the contact position control method for inspecting the electrical characteristics of the specimen, after moving the mounting table on which the subject is placed from the predetermined position S0 to the reference position S1 in the Z-axis direction, the contact position is further moved from the reference position S1. until by specified amounts X moved in the Z-axis direction, a step (I) to obtain the analyte the load becomes to the reference to a contact as a reference torque value Ta to the probe, the subject or to contact state The mounting table on which the next subject following the subject is placed is reciprocated by a specified amount X from the contact position in the Z-axis direction to measure the load changed during the electrical characteristic inspection. Step (II) obtained as a torque value Tb is compared with the reference torque value Ta and the measured torque value Tb, and the mounting table is stepped in the Z-axis direction until the measured torque value Tb becomes substantially the reference torque value Ta. And (III) updating the reference position S1 while repeating the operation of reciprocating the mounting table by the specified amount X after moving the mounting table Y, and thereafter, the mounting table is moved from the reference position in the Z-axis direction. The predetermined amount of movement is updated to (H + h), and the position where the subject contacts the probe is controlled while repeating the steps (II) and (III). Provide a method.

  According to this method, in step (I) and step (II), after the mounting table is moved by a specified amount X in the Z-axis direction, the reference torque value Ta is obtained in step (I), and step (II) To obtain the measured torque value Tb. In step (III), the reference torque value Ta and the measured torque value Tb are compared, and the mounting table is moved (specified amount X−step amount Y) so that the measured torque value Tb becomes substantially the reference torque value Ta. Then, while repeating the operation of moving the specified amount X, the height h is moved by a unit amount (step amount Y) in the Z-axis direction to correct the height position of the mounting table to (H + h). Further, after that, the predetermined amount H by which the mounting table moves in the Z-axis direction from the reference position, that is, the contact position is updated to (H + h), and further, the steps (II) and (III) are repeated, and the object to the probe is repeated. By controlling the contact position, it is possible to create a state in which a difference appears in the motor current value only by the displacement of the contact load. As a result, it is possible to obtain a displacement amount of the motor current value that is simply measured without using a calculation for eliminating the disturbance condition and to use it for the control as it is.

  Furthermore, by making the height after the contact load correction the height of the next contact operation, the contact with the optimum load can be reproduced simply by moving to the specified height position (H + h) in the next contact operation. In this case, since it is not necessary to perform a feedback operation by the motor current, it is not necessary to correct the contact load before the test, and the contact resistance between the subject and the probe can be made constant.

According to a second aspect of the invention the method as claimed in claim 1, wherein the subject is to provide a contact position control method is a semiconductor wafer which electronic devices are formed.

  According to this method, the wafer mounted on the mounting table is brought into contact with the probe provided on the probe card, and electrical characteristics inspection of the electrical device or the like on the semiconductor wafer can be performed.

According to a third aspect of the present invention, in the contact position control method for cleaning the probe by bringing a cleaning material disposed on a mounting table into contact with a probe provided on a probe card, the cleaning material is placed at a predetermined position S0. Is moved from the reference position S1 to the reference position S1 in the Z-axis direction, and is further moved from the reference position S1 to the contact position by the specified amount X in the Z-axis direction to bring the cleaning material into contact with the probe and serve as a reference load. Is set as the reference torque value Ta, and when cleaning the probe, the cleaning material is moved from the predetermined position S0 to the reference position S1 in the Z-axis direction, and further from the reference position S1. Move the specified amount X in the Z-axis direction to contact the probe and torque at the time of contact The step (II) of obtaining the measured torque value Tb is compared with the reference torque value Ta and the measured torque value Tb, and the cleaning material is moved in the Z-axis direction until the measured torque value Tb becomes substantially the reference torque value Ta. After moving the step amount Y, the reference position S1 is updated while repeating the operation of reciprocating the mounting table by the specified amount X, thereby controlling the position where the cleaning material contacts the probe. A position control method is provided.

  According to this method, in step (I), the reference torque Ta is set, and in step (II), the cleaning material is moved by a predetermined amount H from the reference position in the Z-axis direction to obtain the measured torque value Tb. In step (III), the reference torque value Ta and the measured torque value Tb are compared, and the cleaning material is increased by a unit amount (step amount Y) in the Z-axis direction so that the measured torque value Tb becomes substantially the reference torque value Ta. The height of the cleaning material is corrected to (H + h). Thereafter, the cleaning material is updated to a predetermined amount H in which the cleaning material moves in the Z-axis direction from the reference position, that is, the contact position is updated to (H + h), and the cleaning material for the probe is repeated while repeating Step (II) and Step (III). By controlling the contact position, it is possible to create a state in which a difference appears in the motor current value only by the displacement of the contact load. As a result, it is possible to obtain a displacement amount of the motor current value that is simply measured without using a calculation for eliminating the disturbance condition and to use it for the control as it is.

  According to a fourth aspect of the present invention, there is provided the contact position control method according to the third aspect, wherein the cleaning material is formed of a wafer-like disk.

  According to this method, the optimum contact pressure between the cleaning material and the probe provided on the probe card is always maintained, and damage or increase in wear due to excessive force applied to the probe can be prevented. Contributes to extension.

  According to a fifth aspect of the present invention, there is provided the contact position control method according to the third aspect, wherein the cleaning material is disposed on an exchangeable stage that moves in the Z-axis direction with respect to the probe.

  According to this method, when exchanging the cleaning material, it is possible to easily cope with the problem by simply exchanging the stage on which the cleaning material is arranged, which contributes to the improvement of the exchanging work.

  According to the present invention, in the electrical characteristic inspection of the subject, the contact load between the probe and the subject can be accurately set by a simple method without performing complicated calculation that eliminates the disturbance condition. it can.

  In addition, as in the case of the electrical property inspection, the probe can be cleaned by setting the contact load between the probe and the cleaning material to an appropriate load by a simple method without performing complicated calculations that eliminate disturbance conditions. As a result, the cleaning accuracy can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the 1st Example of the test | inspection system to which the contact position control method by embodiment of this invention is applied, The principal part structure is demonstrated. It is a figure explaining the contact operation of a probe and a subject in a contact position control method, (a) is a figure explaining operation at the time of contact (Step (I)) to the 1st semiconductor wafer, (b). FIG. 6 is a diagram for explaining the operation at the step (II) of measuring the load applied to the mounting table whose height of the probe card or the like has fluctuated and changed during the electrical characteristic inspection of the semiconductor wafer, and (c) follows step (II). It is a figure explaining operation after Step (III). It is a flowchart which shows the basic composition of the contact position control method in 1st Example of this invention. It is a figure explaining the 2nd Example of the test | inspection system to which the contact position control method by embodiment of this invention is applied, The principal part structure is demonstrated. It is a flowchart which shows the basic composition of the contact position control method in 2nd Example of this invention. It is a figure explaining the 3rd Example of the test | inspection system to which the contact position control method by embodiment of this invention is applied, The principal part structure is demonstrated. It is a flowchart which shows the basic composition of the contact position control method in 3rd Example of this invention.

In order to achieve the object of the present invention to provide a contact position control method capable of obtaining an appropriate contact load between a probe and a subject without performing complicated calculations in the electrical property inspection of the subject. In the contact position control method for contacting an object arranged on a mounting table with a probe provided on a probe card and performing an electrical property inspection of the object, the mounting table described above in which the object is arranged after allowing to move in the Z axis direction from the predetermined position S0 to the reference position S1, and further specified amount X moved in the Z-axis direction from the reference position S1 to the contact position, by contact of the analyte to the probe Step (I) for obtaining a reference load as a reference torque value Ta, and placing the subject in contact or the next subject following the subject A step (II) of reciprocating a specified amount X from the contact position in the Z-axis direction from the contact position to obtain a weight changed during the electrical characteristic inspection as a measured torque value Tb; and the reference torque value Ta and the The operation of comparing the measured torque value Tb, moving the mounting table by the step amount Y in the Z-axis direction until the measured torque value Tb becomes substantially the reference torque value Ta, and then moving the mounting table by the specified amount X reciprocally. Renewing the reference position S1 repeatedly (III), and thereafter updating the predetermined amount by which the mounting table moves in the Z-axis direction from the reference position to (H + h). ) And step (III) are repeated, and the position where the subject contacts the probe is controlled.

In addition, the present invention provides a contact position control method that can improve the cleaning accuracy for a probe by making the contact load between the probe and the cleaning material constant. In the contact position control method for cleaning the probe by contacting the cleaning material arranged on the mounting table, after moving the cleaning material from the predetermined position S0 to the reference position S1 in the Z-axis direction, A step (I) of moving the designated amount X in the Z-axis direction from the reference position S1 to the contact position, bringing the cleaning material into contact with the probe, and setting a reference load as a reference torque value Ta; When cleaning the probe, place the cleaning material in place. After moving from the reference position S1 to the reference position S1 in the Z-axis direction, the reference position S1 is further moved by a specified amount X in the Z-axis direction to contact the probe, and the torque at the time of contact is obtained as a measured torque value Tb. After the step (II) is compared with the reference torque value Ta and the measured torque value Tb, the cleaning material is moved by the step amount Y in the Z-axis direction until the measured torque value Tb becomes substantially the reference torque value Ta. This was realized by updating the reference position S1 while repeating the operation of reciprocating the mounting table by a specified amount X, thereby controlling the position where the cleaning material contacts the probe.

Hereinafter, a preferred embodiment will be described in detail with reference to the drawings, taking as an example a case where the contact position control method according to the embodiment of the present invention is applied to a system for inspecting an electrical property of an object such as a semiconductor wafer. .

(First embodiment)
FIG. 1 shows a first embodiment of an inspection system to which a contact position control method according to the present invention is applied, and is an explanatory view for explaining the configuration of the main part thereof.

In the figure, an inspection apparatus 10 contacts a semiconductor wafer as a subject with a probe of a probe card to inspect the electrical characteristics of the semiconductor wafer.
In addition to the base 11, the Z stage moving mechanism 12, the mounting table (chuck) 13, the height position detecting means 14, and the Z axis driving servo motor 15 provided on the base 11, a Z axis motor driving unit 16, a Z-axis current measurement unit 17, a mounting table height position control unit 18, a main control unit 19, the probe card 20, and the like.

  The base 11 is provided with a plurality of linear guides 21 projecting upward, and the base 11 is located at a substantially central position in a region surrounded by the plurality of linear guides 21. And a ball screw 22 is disposed in the vertical direction.

  The ball screw 22 is screwed into a screw hole 23 penetrating in the vertical direction of the base 11 and can be moved in the vertical direction according to the rotation direction by the screwing. A rotor portion (not shown) of the Z-axis drive servomotor 15 is attached to the lower end portion of the ball screw 22 protruding to the back surface (lower surface) side of the base 11. Rotate in both forward and reverse directions. The Z-axis drive servo motor 15 is attached with a housing (not shown) on the back side of the base 11 fixed to the stator portion side. The ball screw 22 is rotated in two forward and reverse directions in conjunction with the rotation of the rotor portion. Accordingly, the Z-axis drive servomotor 15 also rotates in two forward and reverse directions. On the other hand, the Z stage moving mechanism 12 is attached to an upper end portion of the ball screw 22 protruding to the surface (upper surface) side of the base 11 so as to be capable of screw feeding.

The Z stage moving mechanism 12 is connected to the plurality of linear guides 21 on the surface side of the base 11, and moves up and down by the guide of the linear guide 21 when the ball screw 22 feeds the screw. It is possible. Moreover, the the top of the Z stage moving mechanism 12, the semiconductor wafer W to the chuck and the mounting table 13 before positionable holding a specimen is mounted movably together with the Z stage moving mechanism 12.

  The height position detecting means 14 is a linear scale 14a attached to the Z stage moving mechanism 12 so as to be movable together, and a scale fixedly attached on the base 11 so as to face the linear scale 14a. It consists of a head 14b. The scale head 14 b detects the height position of the linear scale 14 a that moves in the vertical direction integrally with the Z stage moving mechanism 12, and the detected height position is the height position from the base 11 of the mounting table 13. Information can be output to the table height position control unit 18 described above.

  The Z-axis motor drive unit 16 drives the Z-axis drive motor 15 in accordance with a signal from the mounting table height position control unit 18 described above. The current value driving the Z-axis driving motor 15 is input to the main control unit 19 via the Z current measurement unit 17 and the mounting table height position control unit 18.

  The main control unit 19 is, for example, a computer having a central processing function of the inspection apparatus 10 and performs various processes. In addition, the main control unit 19 is provided with a memory 19a. In the memory 19a, in addition to various processing programs, when the probe 20a of the probe card 20 contacts the electrode pad of the electronic device on the semiconductor wafer W, the inclination between the semiconductor wafer W and the array surface at the tip of the probe 20a, Taking account of variations in the tip position of the probe 20a and the like, an overload for raising the semiconductor wafer W to a position higher than the tip position of the probe 20a so that the electrode pad on the semiconductor wafer W side and the probe 20a are in reliable contact with each other. The drive amount (OD amount) and the like are stored.

  As shown in FIG. 2, the probe card 20 is replaceably attached to a card holder 23 of a tester main body (not shown) above the mounting table 13, and is disposed to face the mounting table 13. Each probe card 20 is provided with the plurality of probes 20 a that are in contact with the electrode pads of the semiconductor wafer W on the surface (lower surface) side facing the mounting table 13. The probe 20a has a spring property, and is brought into contact with the electrode pad of the semiconductor wafer W with a predetermined contact pressure by raising the contact position (contact point) of the electrode pad from the tip position of the probe 20a. Therefore, if all the probes 20a are in contact with the electrode pads of the semiconductor wafer W at a predetermined contact pressure, the entire mounting table 13 is subjected to a contact pressure obtained by multiplying the contact pressure of one probe 20a by the number of probes. . This contact pressure can be known by measuring the current value used in the Z-axis motor drive unit 16 for driving the Z-axis drive motor 15 by the Z-axis current measurement unit 17 and converting the current value. Can be known as the torque value.

  FIG. 3 is a flowchart showing the basic configuration of the contact position control method in the first embodiment of the present invention. The control procedure shown in this flowchart is executed according to a processing program in the main control unit 19.

  Next, the contact position control operation shown in the flowchart will be described together with the contact operation shown in FIG. In the following description, in FIG. 2, when the contact position control operation is performed, the mounting table 13 is moved in the Z-axis direction from the predetermined position S0, and the semiconductor wafer W is brought into contact with the probe 20a in an overdriven state. In order to ignore the force component other than the contact load, the amount of movement necessary for the movement is preliminarily moved in the Z-axis direction from the predetermined position S0 to the reference position S1 before the torque measurement, and the reference position S1 The amount of movement from the contacted position to the contacted position (hereinafter referred to as “contact” position) is “specified amount X”, and the Z-axis drive motor 15 is driven so that the measured torque value Tb becomes the reference torque value Ta. The minimum unit movement amount when moving the mounting table 13 in the Z-axis direction will be described as “step amount Y”. Here, the designated amount X is determined experimentally or empirically.

  First, the flow chart can be broadly divided into the designated amount X from the reference position S1 obtained by moving the mounting table 13 on which the semiconductor wafer W as the subject is placed in the Z-axis direction (predetermined amount H−specified amount X) from the predetermined position S0. In the moving operation, the semiconductor wafer W is brought into contact with the probe 20a, the step (I) for obtaining the torque at the time of contact as the reference torque value Ta, and the subject or the semiconductor wafer W in the contact state. The mounting table 13 on which the next semiconductor wafer W is mounted is reciprocated between the reference position S1 and the contact position, that is, the specified amount X is reciprocated in the Z-axis direction. The step (II) of obtaining the measured torque value Tb is compared with the reference torque value Ta and the measured torque value Tb. The reference position S1 is updated by moving the mounting table 13 by a unit amount in the Z-axis direction (specified amount X−step amount Y) so that the constant torque value Tb becomes substantially the reference torque value Ta. And a step (III) of performing correction while repeating the operation of moving the specified amount X from the reference position S1.

  The step (I) includes steps 101 to 103. First, when an electrical property inspection is started by an external operation by an operator or the like, the main control unit 19 controls the X and Y drive shafts (not shown) to place the mounting table 13, the ball screw 22, the Z stage moving mechanism 12, Z The base 11 is moved so that the shaft driving motor 15 is disposed under the probe card 20, that is, at the predetermined position S0.

  Next, in step 101, the main control unit 19 controls the mounting table height position control unit 18 to step-rotate the Z-axis driving motor 15 in the forward direction via the Z-axis motor driving unit 16, thereby mounting the mounting table 13. Are moved together with the ball screw 22 and the Z stage moving mechanism 12 from the predetermined position S0 to the reference position S1 moved in the Z-axis direction (predetermined amount H−predetermined amount X), and further moved by the specified amount X from the reference position S1. The contact position is raised to the designated position X from the reference position S1. The contact position increased by the designated amount X is a position where the electrode pad of the semiconductor wafer W on the mounting table 13 and the probe 20a of the probe card 20 are in contact with each other with a predetermined overdrive amount OD. It is in a state as shown in (a).

  The movement of the mounting table 13 in the Z-axis direction is detected by a relative position change of the linear scale 14a and the scale head 14b in the height position detecting means 14 or a rotary encoder attached to the motor. The detected position information of the mounting table 13 is input to the main control unit 19 from the rotary encoder attached to the scale head 14b or the motor via the mounting table height position control unit 18, and the main control unit 19 Then, the current height position of the mounting table 13 can be known from the position information.

  In step 102, the Z-axis current measuring unit 17 detects the drive current (Z-axis motor current) of the Z-axis drive motor 15. In step 103, the torque Ta and the amount of movement H of the mounting table 13 moved in the Z-axis direction from the reference position S0 obtained from the height position detecting means 14 are obtained from the Z-axis motor current value. These values are stored in the memory 19a as the reference height position H and the reference torque value Ta.

  Subsequently, the step (II) is entered, and the operation of measuring the load applied to the mounting table 13 whose height of the probe card or the like fluctuates during the electrical property inspection of the semiconductor wafer is started. The step (II) includes steps 104 to 107. In step (II), a reciprocating movement of a specified amount X is performed in the Z-axis direction as an operation before motor current measurement in step 106. In step 107, the value of the Z-axis motor current is measured, and the measured torque Tb is detected from the value of the Z-axis motor current. The measurement torque Tb obtained here is different from the reference torque Ta because the probe 20a moves in the vertical direction as shown in FIG. 2B due to deformation of the probe card 20 or the like.

  Subsequently, the step (III) is entered, and the torque reproduction operation is started. The step (III) includes steps 108 to 110. In step 108, the reference torque value Ta and the measured torque Tb are compared to determine whether the measured torque Tb is within the range of the reference torque value Ta (within the range of the reference value). If it is not within the range of the reference value, the direction (upward or downward) in which the mounting table 13 is moved for correction is determined at step 109 depending on whether it is larger or smaller than the range. In step 110, the mounting table 13 is moved upward or downward in the Z-axis direction (specified amount X−step amount Y) to update the reference position S1, and the mounting table 13 is updated from the updated reference position S1. 2 to move the specified amount X in the Z-axis direction and return to step 107, and repeatedly adjust the mounting table 13 in the upward or downward direction as shown in FIG. 2C, and the measured torque value Tb becomes the reference torque value. Correction is made so as to be within the range of Ta (Tb → Ta).

  On the other hand, when the measured torque Tb is within the range of the reference torque value Ta (within the range of the reference value) at step 108 or within the range due to correction, the routine proceeds to step 111. In step 111, the current contact height (height position of the mounting table 13) is measured. In step 112, the contact height is compared with the contact height H to determine whether the height has changed. Here, when the contact height H is changed by the height h, that is, when the height is (H + h), the overdrive amount is calculated from the difference h, and the mounting table 13 is moved to the predetermined position S0. The reference height (H) to be increased by a predetermined amount is updated to (H + h), and then the process proceeds to step 114 where the mounting table 13 is lowered to the predetermined position S0.

  From step 114, the process proceeds to step 115, where it is determined whether or not the semiconductor wafer W being inspected is the last semiconductor wafer and is the last wafer contact position. Control goes to step 116.

  In step 116, the main controller 19 controls the XY axes (not shown) and moves the electronic device of the next semiconductor wafer W to a position corresponding to the probe 20a. Thereafter, in step 117, the mounting table 13 is moved from the predetermined position S0 in the Z-axis direction (H + h), and contact with the probe 20a is performed with an optimal overdrive amount as shown in FIG. In step 118, the measured torque Ta is measured from the Z-axis motor current at that time. Thereafter, the process proceeds to step 119.

  In step 119, it is detected whether or not the measured torque Tb obtained from the Z-axis motor current in step 118 is within the range of the reference torque value Ta (within the range of the reference value). The process proceeds to step 104, and the same operation is repeated thereafter. On the other hand, when the measured torque Tb is not within the range of the reference torque value Ta (within the range of the reference value) at step 119, it is processed as an error. That is, after step (III), the predetermined amount H by which the mounting table 13 moves in the Z-axis direction from the predetermined position S0 is updated to (H + h), and the motor current is measured after the operation of the specified amount X. The contact position of the subject (wafer W) with respect to the probe is controlled while repeating the steps (II) and (III).

  Therefore, according to the first embodiment, in the electrical characteristic inspection of the subject, the contact position between the probe and the subject is set to an appropriate position by a simple method without performing a complicated calculation that eliminates the disturbance condition. Since the appropriate reference torque Ta is always reproduced and applied, the electrical characteristics can be inspected with high accuracy.

(Second embodiment)
FIG. 4 shows a second embodiment of the inspection system to which the contact position control method according to the present invention is applied, and is an explanatory diagram for explaining the configuration of the main part thereof. The second embodiment shows a case where the contact position is controlled when the contact surface of the probe 20a in the probe card 20 is cleaned using the inspection apparatus 10 of the first embodiment shown in FIGS. ing. Therefore, in FIG. 4, the members corresponding to those in FIGS.

  In the figure, when the probe 20a in the probe card 20 of the inspection apparatus 10 is cleaned, the cleaning material 25 is positioned and arranged on the mounting table 13 on which the semiconductor wafer W is positioned and arranged. Then, the cleaning material 25 is moved in the vertical direction together with the mounting table 13, and the cleaning surface of the cleaning material 25 is brought into contact with the contact surface of the probe 20a to perform cleaning. Further, the cleaning material 25 here is formed as a disk having substantially the same wafer shape as the semiconductor wafer W, and a cleaning surface is provided on the surface facing the probe card 20.

  FIG. 5 is a flowchart showing the basic configuration of the contact position control method according to the second embodiment of the present invention. The control procedure shown in this flowchart is executed according to a processing program in the main control unit 19.

  Next, the contact position control operation during the cleaning will be described with reference to the flowchart shown in FIG. First, the flowchart can be broadly divided. After the cleaning material 25 is moved from the predetermined position S0 to the reference position S1 in the Z-axis direction, the cleaning material 25 is further moved from the reference position S1 by the specified amount X in the Z-axis direction, and the probe 20a Step (I) in which the cleaning material 25 is brought into contact and the torque at the time of contact is set in advance in the memory 19a of the main controller 19 as a reference torque value Ta, and after the reference torque value Ta is acquired, When cleaning the probe, the cleaning material 25 is moved from the predetermined position S0 to the reference position S1 in the Z-axis direction, and is further moved from the reference position S1 by the specified amount X in the Z-axis direction to contact the probe. Obtaining the torque at the time of contact as a measured torque value Tb (II), and the reference torque value Ta A step of comparing the measured torque value Tb and correcting the height position by moving the cleaning material 25 in the Z-axis direction by height h so that the measured torque value Tb becomes substantially the reference torque value Ta (III ).

  The step (I) is set in advance by an external operation by an operator or the like, for example. In step (II), when a cleaning instruction is given, in step 201, the main control unit 19 controls the X and Y drive shafts (not shown), the mounting table 13, the ball screw 22, the Z stage moving mechanism 12, and the Z axis. The base 11 is moved so that the drive motor 15 is disposed under the probe card 20, that is, at the predetermined position S0.

  Next, in step 202, the main control unit 19 controls the mounting table height position control unit 18, rotates the Z-axis driving motor 15 in the forward direction via the Z-axis motor driving unit 16, and moves the mounting table 13. Along with the ball screw 22 and the Z stage moving mechanism 12, it is moved from the predetermined position S0 to the reference position S1 moved in the Z-axis direction (predetermined amount H-specified amount X), and further moved upward from the reference position S1 by the specified amount X. The mounting table 13 is placed at a contact position that is a specified amount X higher than the position S1. The contact position increased by the designated amount X is a position where the contact surface of the cleaning material 25 on the mounting table 13 and the probe 20a of the probe card 20 are in contact at a predetermined cleaning height. In step 203, the Z-axis current measuring unit 17 detects the drive current (Z-axis motor current) of the Z-axis drive motor 15 after the reciprocation of the designated amount X in the Z-axis direction.

  Then, the step (III) is entered. The step (III) is step 204, in which the reference torque value Ta and the measured torque Tb are compared to determine whether the measured torque Tb is within the range of the reference torque value Ta (within the range of the reference value). . If it is not within the range of the reference value, the direction (upward or downward) of moving the mounting table 13 for correction is determined at step 205 depending on whether it is larger or smaller than the range, and the mounting table 13 is moved at step 206. After moving the step amount Y in the Z-axis direction, the measured torque Tb is measured in step 203 while repeating the operation of reciprocating the mounting table 13 by the specified amount X, and the measured torque value Tb is within the range of the reference torque value Ta. Correction is made so that (Tb → Ta).

  On the other hand, when the measured torque Tb is within the range of the reference torque value Ta (within the range of the reference value) at step 204 or within the range due to correction, the routine proceeds to step 207. In step 207, the current contact height (height position of the mounting table 13) is measured, and the height position is updated to (H + h) and stored in the memory 19a. Return to. This completes the first cleaning.

  When the cleaning instruction is given for the second and subsequent times, in step 209, the mounting table 13, the ball screw 22, the Z stage moving mechanism 12, the ball screw 22, and the Z-axis drive motor 15 are arranged below the probe card 20 together with the base 11. Further, the initial stage 13 is gradually moved upward from the reference position S0 to the predetermined height position (H + h) updated by the first cleaning.

  In step 210, the Z-axis motor current value is measured after the reciprocation of the specified amount X from the cleaning height in the Z-axis direction, and the measured torque Tb is measured from the Z-axis motor current value. In step 211, the measured torque is measured. It is determined whether Tb is within the range of the reference torque value Ta (within the range of the reference value). If it is within the range of the reference value, cleaning is performed at step 210. If it is not within the range, the process returns to step 202, the reference torque value Ta and the predetermined height position (H + h) are updated again, and thereafter the control is repeated.

  Therefore, according to the second embodiment, in the cleaning of the probe 20a, the contact position between the probe 20a and the cleaning material 25 is set to an appropriate position by a simple method without performing complicated calculation that eliminates the disturbance condition. Since the appropriate reference torque Ta is always reproduced and applied, cleaning can be performed with high accuracy.

(Third embodiment)
FIG. 4 shows a third embodiment of the inspection system to which the contact position control method according to the present invention is applied, and is an explanatory diagram for explaining the configuration of the main part thereof. The second embodiment shown in FIGS. 4 and 5 discloses a structure in which the cleaning material 25 is arranged on the mounting table 13 of the inspection apparatus 10 instead of the semiconductor wafer W to perform cleaning. In the embodiment, a dedicated cleaning device is prepared separately from the inspection device 10, and the contact surface of the probe 20 a in the probe card 20 is cleaned using the cleaning device. The F axis described below is the moving direction of the mounting table 13 and is the same as the Z axis described in the first and second embodiments.

  In the figure, a cleaning device 30 includes a base 31, an F stage moving mechanism 32 provided on the base 31, a mounting base (cleaning stage chuck) 33, a height position detecting means 34, and an F axis. In addition to the drive servo motor 35, the motor includes an F-axis motor drive unit 36, an F-axis current measurement unit 37, a mounting table height position control unit 38, a main control unit 39, and the like. The probe card 20 is the same as the probe card of the first and second embodiments.

  The base 31 is provided with a plurality of linear guides 41 projecting upward, and the base 31 is provided at a substantially central position in a region surrounded by the plurality of linear guides 41. And a ball screw 42 is disposed in the vertical direction.

  The ball screw 42 is screwed into a screw hole 43 penetrating in the vertical direction of the base 31 and can be moved in the vertical direction according to the rotation direction by the screwing. Further, a rotor portion (not shown) of the F-axis drive servomotor 35 is attached to the lower end portion of the ball screw 42 protruding to the back surface (lower surface) side of the base 31. Rotate in both forward and reverse directions. The F-axis drive servomotor 35 is fixedly attached to the rear surface side of the base 31 with a housing (not shown) on the stator portion side. The ball screw 42 is rotated in two forward and reverse directions in conjunction with the rotation of the rotor portion. Accordingly, the F-axis drive servomotor 35 also rotates in two forward and reverse directions. On the other hand, the F stage moving mechanism 32 is attached to the upper end portion of the ball screw 42 protruding to the surface (upper surface) side of the base 31 so as to be capable of screw feeding.

  The F-axis stage moving mechanism 32 is connected to the plurality of linear guides 41 on the surface side of the base 31, and moves up and down by the guide of the linear guide 41 when the ball screw 42 feeds the screw. It can be moved. Further, the mounting table 33 on which the sheet-like cleaning material 45 is attached is attached to the upper part of the F stage moving mechanism 32 so as to be movable together with the F stage moving mechanism 12.

  The height position detecting means 34 is a linear scale 34a attached to the F stage moving mechanism 32 so as to be movable together, and a scale fixedly attached on the base 31 so as to face the linear scale 34a. It consists of a head 34b. The scale head 34 b detects the height position of the linear scale 34 a that moves in the vertical direction integrally with the F stage moving mechanism 32, and the detected height position is the height position from the base 31 of the mounting table 33. Information can be output to the table height position control unit 38 described above. The height position information from the base 31 of the mounting table 33 can be output from a rotary encoder attached to the motor instead of the height position detecting means 34.

  The F-axis motor drive unit 36 drives the F-axis drive motor 35 in accordance with the signal from the mounting table height position control unit 38. The current value driving the F-axis drive motor 35 is input to the main control unit 39 via the F-axis current measurement unit 37 and the mounting table height position control unit 38.

  The main control unit 39 is, for example, a computer having a central processing function of the cleaning device 10 and performs various processes. In addition to various processing programs, the main control unit 39 also includes the inclination of the cleaning material 45 and the array surface at the tip of the probe 20a at the time of contact between the probe 20a of the probe card 20 and the cleaning material 45, and the probe. In consideration of variations in the tip position of 20a, etc., the cleaning height for raising the cleaning material 45 to a position higher than the tip position of the probe 20a is stored so that the cleaning material 45 and the probe 20a come into reliable contact. A memory 39a is provided.

  FIG. 7 is a flowchart showing the basic configuration of the contact position control method according to the third embodiment of the present invention. The control procedure shown in this flowchart is executed according to a processing program in the main control unit 39.

  Next, the contact position control operation during the cleaning will be described with reference to the flowchart shown in FIG. First, the flow chart can be broadly divided to move the cleaning material 45 by a predetermined amount H from the reference position S0 in the F-axis direction so that the cleaning material 45 is brought into contact with the probe 20a, and the torque at the time of contact is the reference torque value Ta. When the probe 20a is cleaned after the step (I) previously set in the memory 39a of the main controller 39 and the reference torque value Ta is acquired, the cleaning material 45 is moved from the reference position S0 to F. Step (II) in which a predetermined amount H is moved in the axial direction to contact the probe 20a and the torque at the time of contact is obtained as the measured torque value Tb is compared with the reference torque value Ta and the measured torque value Tb, and the measured torque The cleaning material 45 has a height h in the F-axis direction so that the value Tb is substantially equal to the reference torque value Ta. Step amount Y) is moved consisting the step (III) to correct the height position.

  In step (I), for example, a reference torque Ta is set in advance by an external operation by an operator or the like. In the step (II), when there is a cleaning instruction, the main control unit 39 controls the X and Y drive shafts (not shown) in step 301 to drive the mounting table 33 and the ball screw 42, the F stage moving mechanism 32, and the F axis drive. The base 31 is moved so that the motor 35 is disposed below the probe card 20, that is, at the predetermined position S0.

Next, in step 302, the main control unit 39 controls the mounting table height position control unit 38 to step-rotate the F-axis driving motor 35 in the forward direction via the F-axis motor driving unit 36, thereby mounting table 33. Is moved together with the ball screw 42 and the F stage moving mechanism 32 to the reference position S1 moved in the F-axis direction (predetermined amount H−specified amount X), and further moved upward by the operation of moving the specified amount X from the reference position S1. The mounting table 33 is arranged at a contact position that is a specified amount X higher than the position S1. The position where the predetermined amount H is raised is a position where the contact surface of the cleaning material 45 on the mounting table 33 and the probe 20a of the probe card 20 are in contact with each other at a predetermined cleaning height. In step 303, the drive current (F-axis motor current) of the F-axis drive motor 35 is detected by the F-axis current measurement unit 37 after the reciprocation of the specified amount X in the F-axis direction.

  Then, the step (III) is entered. The step (III) is step 304, in which the reference torque value Ta and the measured torque Tb are compared to determine whether the measured torque Tb is within the range of the reference torque value Ta (within the range of the reference value). . If it is not within the range of the reference value, the direction (upward or downward) of moving the mounting table 33 for correction is determined depending on whether it is larger or smaller than the range in step 305, and the mounting table 33 is moved in step 306. After the step amount Y is moved in the F-axis direction, the measured torque Tb is measured in step 303 while repeating the operation of reciprocating the mounting table 33 by the specified amount X, and the measured torque value Tb is within the range of the reference torque value Ta. Correction is made so that (Tb → Ta).

  On the other hand, when the measured torque Tb is within the range of the reference torque value Ta (within the range of the reference value) or within the range due to the correction in step 304, the process proceeds to step 307. In step 307, the current contact height (height position of the mounting table 13) is measured, and the height position is updated to (H + h) and stored in the memory 39a. Return to position. This completes the first cleaning.

  When the cleaning instruction is given for the second and subsequent times, in step 309, the mounting table 33, the ball screw 42, the F stage moving mechanism 32, the ball screw 42, and the F-axis drive motor 35 are arranged below the probe card 20 together with the base 31. Further, the mounting table 33 is gradually moved upward from the reference position S0 to the predetermined height position (H + h) updated by the first cleaning.

  Then, after reciprocating the specified amount X from the reference position S1 in the F-axis direction in Step 310, the F-axis motor current value is measured, and the measured torque Tb is measured from the F-axis motor current value. In Step 311, the measured torque is measured. It is determined whether Tb is within the range of the reference torque value Ta (within the range of the reference value). If it is within the range of the reference value, cleaning is performed in step 312. If it is not within the range, the process returns to step 302, the reference torque value Ta and the predetermined height position (H + h) are updated again, and thereafter the control is repeated.

  Therefore, according to the third embodiment, in the cleaning of the probe 20a, the contact position between the probe 20a and the cleaning material 25 is set to an appropriate position by a simple method without performing a complicated calculation that eliminates the disturbance condition. Since the appropriate reference torque Ta is always reproduced and applied, cleaning can be performed with high accuracy.

  It should be noted that the present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

  The present invention can also be applied to techniques other than contacting the semiconductor wafer W and the probe.

10 Inspection equipment 11 Base (base)
12 Z stage moving mechanism 13 Mounting table (chuck)
14 Height position detection means 14a Linear scale 14b Scale head 15 Z-axis drive motor 16 Z-axis motor drive unit 17 Z-axis current measurement unit 18 Mounting table height position control unit 19 Main control unit 19a Memory 20 Probe card 20a Probe 21 Linear guide 22 Ball screw 23 Screw hole 24 Card holder 25 Cleaning material 30 Cleaning device 31 Base (base)
32 F stage moving mechanism 33 Mounting table (cleaning stage)
34 Height position detection means 34a Linear scale 34b Scale head 35 F-axis drive motor 36 F-axis motor drive unit 37 F-axis current measurement unit 38 Mounting table height position control unit 39 Main control unit 39a Memory 41 Linear guide 42 Ball screw 43 Screw hole 45 Cleaning material W Semiconductor wafer (subject)

Claims (5)

In a contact position control method for contacting an object placed on a mounting table with a probe provided on a probe card and performing an electrical property test on the object,
After moving in the Z axis direction mounting table before placing the object from the predetermined position S0 to the reference position S1, thereby further specified amount X moved in the Z-axis direction from the reference position S1 to the contact position, the analyte A step (I) of obtaining a reference load as a reference torque value Ta by contacting the probe;
Measure the load that changed during the electrical property inspection by reciprocating the specified amount X in the Z-axis direction from the contact position on the mounting table on which the subject in contact or the next subject following the subject is placed Step (II) to obtain as torque value Tb;
The reference torque value Ta is compared with the measured torque value Tb, and the mounting table is moved by a step amount Y in the Z-axis direction until the measured torque value Tb becomes substantially the reference torque value Ta, and then the mounting table is designated. Step (III) of updating the reference position S1 while repeating the operation of reciprocating by the amount X;
Thereafter, the position where the subject contacts the probe is controlled while repeating the step (II) and the step (III). It said contact position control method according to claim 1, wherein it is a semiconductor wafer on which the subject is, electronic devices are formed. In the contact position control method for cleaning the probe by contacting a cleaning material arranged on the mounting table with respect to the probe provided on the probe card,
After the cleaning material is moved from the predetermined position S0 to the reference position S1 in the Z-axis direction, the cleaning material is further moved by a specified amount X from the reference position S1 to the contact position in the Z-axis direction, and the cleaning material is moved with respect to the probe. A step (I) of setting a reference load as a reference torque value Ta by making contact,
When cleaning the probe, the cleaning material is moved by a specified amount X from the reference position S1 in the Z-axis direction and brought into contact with the probe, and a torque at the time of contact is obtained as a measured torque value Tb; ,
The reference torque value Ta and the measured torque value Tb are compared, the cleaning material is moved by a step amount Y in the Z-axis direction until the measured torque value Tb becomes substantially the reference torque value Ta, and then the mounting table is designated. The contact position control method, wherein the reference position S1 is updated while repeating the operation of reciprocating by the amount X to control the position where the cleaning material contacts the probe.   4. The contact position control method according to claim 3, wherein the cleaning material is formed of a wafer-like disk.   The contact position control method according to claim 3, wherein the cleaning material is disposed on a replaceable stage that moves in the Z-axis direction with respect to the probe.