JP2017183743A - Prober - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a prober for preventing collision between a probe and a probe position detection camera.SOLUTION: A prober for performing inspection by bringing a probe into contact with an electrode of a wafer that is disposed to face the probe includes: a probe position detection camera which detects a tip-end position of the probe at a position where the probe position detection camera faces the probe; and a probe height detector which is provided separately from the probe position detection camera and which detects the height position of a tip-end of the probe at a position where the probe height detector faces the probe.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a prober that performs electrical inspection of a plurality of chips formed on a semiconductor wafer.

  In the semiconductor manufacturing process, in the dicing process, a disk-shaped semiconductor wafer fixed to a dicing frame by a dicing apparatus is cut into a plurality of chips (dies). A wafer test process for inspecting the electrical characteristics of each chip is performed before or after the dicing process, and a prober is used in the wafer test process.

  In the wafer test process in a prober, it is necessary to accurately bring the tip of a probe card needle (probe) installed in the prober into contact with the wafer. Therefore, it is necessary to detect the position of the tip of the probe with high accuracy as a pre-stage of the wafer test process in the prober.

  So far, a technique for detecting the position of the tip of the probe of the probe card has been proposed.

  For example, in the technique described in Patent Document 1, a technique for detecting a probe by imaging the probe of the probe card with a microscope (probe position detection camera) from below is described. In the technique described in Patent Document 1, the probe position detection camera is driven up and down in the Z-axis direction, and the position of the probe tip is detected by adjusting the focus of the probe position detection camera to the tip of the probe.

Japanese Patent Laid-Open No. 2004-39752

  However, in the technique described in Patent Document 1, when the probe position detection camera is raised along the Z-axis direction, the probe position detection camera is raised too much due to an operator error or incorrect data input. There is a risk of collision with the probe position detection camera.

  For example, when the tip of the probe is detected by the probe position detection camera after the probe card has been replaced, the probe length or position changes due to the replacement of the probe card, so a collision occurs between the probe position detection camera and the probe. Sometimes. There are various types of probe cards depending on the chip and measurement purpose, and the probe length may change when the type of probe card changes.

  Further, for example, information such as configuration data and product type parameters is input to the prober by an operator (or user), and the probe position detection camera is raised using the information, but there is a case where the input of the information is incorrect. If the information is input incorrectly, the probe position detection camera is raised along the Z-axis direction based on the incorrect information, and the probe and the probe position detection camera may collide.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a prober that prevents a collision between a probe and a probe position detection camera.

  In order to achieve the above object, a prober according to one aspect of the present invention is a prober that performs inspection by bringing a probe into contact with an electrode of a wafer, and performs relative alignment between the electrode of the wafer and the probe. Therefore, a probe position detection camera for detecting the probe tip position and a probe position detection camera provided separately from the probe position detection camera for detecting the height of the probe tip from the reference plane serving as a reference for the height of the probe position detection camera A height detector; and a first height adjustment mechanism configured to change a height of the probe position detection camera from the reference plane based on a detection result of the probe height detector.

  According to this aspect, the height of the tip of the probe is detected by the probe height detector provided separately from the probe position detection camera, and the first height adjustment mechanism is based on the detected height of the tip of the probe. Thus, the height of the probe position detection camera can be changed. As a result, in this aspect, even if the probe card is replaced or there is an error in the input information (configuration data, product type parameter), the height of the probe tip is measured by the probe height detector. Therefore, the height of the tip of the probe is accurately detected, and the occurrence of a collision between the probe position detection camera and the probe can be prevented.

  Preferably, the probe height detector has a contact surface that contacts the tip of the probe, and a contact type that detects the height of the contact surface when the tip of the probe contacts the contact surface as the height of the tip of the probe Detector.

  According to this aspect, the probe height detector has the contact surface and detects the height of the tip of the probe by bringing the contact surface into contact with the tip of the probe. Therefore, the height of the tip of the probe is more accurately determined. It can be detected quickly.

  Preferably, the probe height detector includes a linear variable differential transformer that detects contact of the probe tip to the contact surface.

  According to this aspect, the detection accuracy of the contact of the tip of the probe with the contact surface can be improved. As a result, the measurement accuracy of the height of the tip of the probe from the reference surface can be improved. Further, it is possible to accurately detect the amount of movement (pushing amount) of the contact surface associated with the contact of the tip of the probe with the contact surface and the pressing force associated with the contact.

  Preferably, the probe height detector is provided integrally with the probe position detection camera, and the height of the contact surface of the probe height detector is provided at a position higher than the height of the end of the objective lens of the probe position detection camera. It is done.

  According to this aspect, since the probe height detector is provided integrally with the probe position detection camera, the height of the probe height detector can be changed by the height adjustment mechanism of the probe position detection camera. As a result, this aspect does not require a separate height adjustment mechanism for the probe height detector, can reduce the number of height adjustment mechanisms, and can simplify the control of the height adjustment mechanism and the manufacture of the prober. Realize.

  According to this aspect, since the height of the contact surface of the probe height detector is provided at a position higher than the height of the probe position detection camera, the probe height is detected before the tip of the probe collides with the probe position detection camera. The contact with the detector can prevent occurrence of a collision between the probe position detection camera and the tip of the probe.

  Preferably, the contact surface of the probe height detector is provided at a position lower than a height obtained by adding the working distance of the probe position detection camera to the height of the probe position detection camera.

  According to this aspect, the height of the contact surface of the probe height detector is set at a position lower than the height of the probe position detection camera plus the working distance of the probe position detection camera. As a result, when the probe position detection camera is detecting the tip of the probe, the probe height detector comes into contact with the tip of the probe, which is an obstacle to the detection operation of the probe position detection camera. To prevent.

  Preferably, the probe height detector further includes a second height adjustment mechanism that is provided independently of the probe position detection camera and changes the height of the probe height detector from the reference plane.

  According to this aspect, the probe height detector is provided independently of the probe position detection camera, and includes a height adjustment mechanism that changes the height of the probe height detector. Accordingly, in this aspect, the height of the probe tip can be detected more efficiently because the probe height detector and the probe position detection camera adjust the height independently.

  A prober operation method according to another aspect of the present invention is a prober operation method in which a probe is brought into contact with an electrode of a wafer for inspection, and a probe height detector provided separately from a probe position detection camera is used. Detecting the height of the tip of the probe from the reference surface, which is the height reference of the probe position detection camera, and the detection result of the probe position detection camera from the reference surface based on the detection result of the probe height detector. Changing the height, and detecting a tip position of the probe to perform relative alignment between the electrode of the wafer and the probe using a probe position detection camera.

  Preferably, in the step of detecting the height of the tip of the probe, the probe height having a contact surface that contacts the tip of the probe and a linear variable differential transformer that detects contact of the tip of the probe with the contact surface. A detector is used to detect the height of the probe tip.

  According to the present invention, the probe position detection camera and the probe height detector provided separately from the probe position detection camera are provided, and the first height adjustment mechanism is the tip of the probe detected by the probe height detector. Since the height of the probe position detection camera is changed based on the height of the probe, the occurrence of a collision between the probe position detection camera and the probe can be prevented.

1 is a schematic configuration diagram showing a wafer test system. It is a conceptual diagram which shows the case where the height of the tip of a probe is detected only with a probe position detection camera. It is a figure explaining the height detection of the front-end | tip of the probe performed by a probe height detector. It is the figure which showed notionally the information input into a control part, and the information output from a control part with a functional block. It is the flowchart which showed the operating method of the prober. It is the flowchart which showed the other operation method of the prober. 1 is a schematic configuration diagram showing a wafer test system. It is a figure explaining the height detection of the front-end | tip of a probe. It is a figure explaining the inclination detection of a card holder or a probe card. It is a figure which shows that the inclination of a probe card is detected by the probe height detector. It is the figure which showed notionally the information input into a control part, and the information output from a control part with a functional block. It is a figure which shows that the inclination of a probe card is detected by the probe position detection camera. It is the flowchart which showed the procedure which detects inclination. It is explanatory drawing for demonstrating the probe height detector of another embodiment.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

<First Embodiment>
FIG. 1 is a schematic configuration diagram showing a first embodiment of a wafer test system to which the present invention is applied. As shown in the figure, a wafer test system 100 is connected to a prober 10 that makes a probe 25 contact an electrode of each chip on a wafer W, and the probe 25, and a current is supplied to each chip for electrical inspection. And a tester 30 for applying a voltage and measuring characteristics.

  The prober 10 includes a base 11, a moving base 12, a Y-axis moving table 13, an X-axis moving table 14, a Z-axis moving / rotating unit 15, a wafer chuck 16, and a probe position. A detection camera 18, a probe height detector 20, height adjustment mechanisms 21 and 27, a wafer alignment camera 19, a head stage 22, a card holder 23 provided on the head stage 22, and a card holder 23. It has a probe card 24 and a control unit 60 (computer) that controls each part of the prober 10 and the tester 30. A probe 25 is provided on the probe card 24.

  The movement base 12, the Y-axis movement table 13, the X-axis movement table 14, and the Z-axis movement / rotation unit 15 constitute a movement rotation mechanism that rotates the wafer chuck 16 in the three axis directions and around the Z axis. Since the moving and rotating mechanism is widely known, the description thereof is omitted here.

  The wafer chuck 16 holds a wafer W on which a plurality of chips are formed by vacuum suction. The wafer chuck 16 has a chip in a high temperature state, for example, a maximum of 150 ° C., or a low temperature state, for example, a minimum. A heating / cooling mechanism (heating / cooling mechanism) is provided as a heating / cooling source so that electrical characteristic inspection can be performed at −40 ° C. As the heating / cooling mechanism, a known appropriate heater / cooler can be adopted, for example, a double layer structure of a heating layer of a surface heater and a cooling layer provided with a passage for cooling fluid, Various devices such as a heating / cooling device having a single layer structure in which a cooling pipe around which a heater is wound are embedded in a heat conductor are conceivable. Further, instead of electrical heating, a thermal fluid may be circulated, and a Peltier element may be used.

  The wafer chuck 16 is mounted on the Z-axis moving / rotating unit 15 and can be moved in the three-axis directions (X, Y, and Z-axis directions) by the above-described moving and rotating mechanism, and rotated around the Z-axis. It can be rotated in the direction (θ direction).

  A probe card 24 is disposed above the wafer chuck 16 on which the wafer W is held. The probe card 24 is mounted with a card holder 23 attached to the opening of the head stage 22 that constitutes the top plate of the housing of the prober 10.

  The probe card 24 has a probe 25 arranged according to the electrode arrangement of the chip to be inspected, and is exchanged according to the chip to be inspected. The probe card 24 is an example of a probe holding unit.

  The tester 30 includes a tester body 31 and a contact ring 32 provided on the tester body 31. The probe card 24 is provided with a terminal connected to each probe 25, 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).

  The probe position detection camera 18 detects the position of the tip of the probe 25 in order to perform relative alignment between the electrode of the wafer W and the probe 25. The probe position detection camera 18 is mounted on the X-axis moving table 14 and can be moved in the XY direction integrally with the wafer chuck 16 by the X-axis moving table 14 and the Y-axis moving table 13. The probe position detection camera 18 is moved up and down in the Z-axis direction by the height adjustment mechanism 21 controlled by the control unit 60. The probe position detection camera 18 images the probe 25 of the probe card 24 from below and detects the tip position of the probe 25. The position (X and Y coordinates) of the tip of the probe 25 in the horizontal plane is detected by the coordinates of the camera, and the position in the vertical direction (Z-axis direction), that is, the height of the tip of the probe 25 (probing height) is the focus of the camera. Detected by position. A detection result by the probe position detection camera 18 is input to the control unit 60. As the probe position detection camera 18, for example, a camera provided with a needle alignment microscope provided with an objective lens 18a is used (see FIG. 2).

  The wafer alignment camera 19 is disposed in an alignment region adjacent to the probe region where the probe card 24 is disposed. The wafer alignment camera 19 is supported by a support column (not shown) and can be moved in the Z-axis direction (vertical direction) by a camera lifting mechanism (not shown). The camera lifting mechanism may be a known linear moving mechanism, and is configured by, for example, a linear guide mechanism, a ball screw mechanism, and the like, and is driven by an output from the control unit 60. The wafer alignment camera 19 captures an image of the wafer W held by the wafer chuck 16 from above and detects the position of a chip electrode (chip surface electrode) formed on the surface of the wafer W. The detection result by the wafer alignment camera 19 is input to the control unit 60. The control unit 60 uses a known image processing technique on the basis of the information obtained by the wafer alignment camera 19 and the position information of the tip of the probe 25 obtained by the probe position detection camera 18, and the probe 25 and the wafer. The two-dimensional position alignment in the XY plane of the W chip electrode (chip surface electrode) is automatically performed.

  The probe height detector 20 is provided separately from the probe position detection camera 18 and detects the height of the tip of the probe 25 from the reference plane that serves as a reference for the height of the probe position detection camera 18. The probe height detector 20 is a so-called contact-type detector, and detects the height of the tip of the probe 25 by physically contacting the tip of the probe 25. The probe height detector 20 is not particularly limited as long as it can physically contact the tip of the probe 25 and detect the height of the tip of the probe 25, and a known technique is applied. Here, the reference plane is a plane that serves as a reference for the height of the prober 10 as a whole, and is arbitrarily set. For example, the reference plane is set on the upper surface of the X-axis moving table 14. Note that the probe height detector 20 is not limited to the one that detects the tip of the probe 25 by physical contact, and a technique for detecting the tip of the known probe 25 can also be employed. For example, the probe height detector 20 may detect the tip of the probe 25 by a non-contact method.

  The probe height detector 20 includes a contact surface 20a and a sensor mechanism 20b (see FIG. 3). The contact surface 20a contacts the tip of the probe 25, and outputs a signal to the sensor mechanism 20b when contacted. The sensor mechanism 20b receives the signal output from the contact surface 20a and the signal related to the height output from the height adjusting mechanism 27, and outputs information related to the height of the tip of the probe to the control unit 60. That is, the sensor mechanism 20b makes the control unit 60 contact the contact surface 20a with the tip of the probe 25 as the height of the tip of the probe 25 when the tip of the probe 25 contacts the contact surface 20a. Output.

  The height adjustment mechanism 21 (first height adjustment mechanism) of the probe position detection camera 18 drives the probe position detection camera 18 up and down along the Z-axis direction under the control of the control unit 60. The height adjustment mechanism 21 is controlled by the control unit 60 (FIG. 4) of the prober 10, and the elevation drive is controlled by a user or a program incorporated in the control unit 60. For example, the height adjustment mechanism 21 changes the height of the probe position detection camera 18 from the reference plane based on the detection result of the probe height detector 20. That is, the height adjustment mechanism 21 adjusts the probe position detection camera 18 to a height away from the distal end of the probe 25 based on the height of the distal end of the probe 25 measured by the probe height detector 20. In this way, the height of the probe position detection camera is adjusted using the height of the probe tip once detected by the probe height detector 20, and therefore the probe position detection camera 18 may be raised too much. Thus, it is possible to prevent the probe position detection camera 18 from colliding with the tip of the probe 25 by driving up and down along the Z-axis direction.

  The height adjustment mechanism 27 (second height adjustment mechanism) of the probe height detector 20 drives the probe height detector 20 up and down along the Z axis. The height adjustment mechanism 27 is provided independently of the height adjustment mechanism 21 described above, and is controlled by the control unit 60 similarly to the height adjustment mechanism 21 to drive the probe height detector 20 up and down. .

  The control unit 60 can control the entire wafer test system 100 (prober 10 / tester 30) and is configured by a computer. The controller 60 is connected to each part of the wafer test system 100 (not shown), and can receive signals from each part of the wafer test system 100 and transmit signals to each part. The computer constituting the control unit 60 has an input unit 62 and a display unit 61. The user inputs information through the input unit 62, and the control unit 60 displays information on the display unit 61, thereby giving an error to the user. Etc.

  FIG. 2 is a conceptual diagram showing a case where the height of the tip of the probe 25 is detected only by the probe position detection camera 18.

  FIG. 2A is a conceptual diagram when the probe position detection camera 18 normally detects the tip of the probe 25. When the probe position detection camera 18 detects the height of the tip of the probe 25, first, configuration data, product parameters, and the like are input by the user to the control unit 60 via the input unit 62, and based on the input values. The controller 60 calculates a distance A between the wafer chuck 16 and the tip of the probe 25. Based on the calculated distance A, the probe position detection camera 18 is at a stretch to a height (working distance height) at which the probe position detection camera 18 and the tip of the probe 25 are separated from each other by a working distance (denoted as WD in the drawing). It is raised by the adjusting mechanism 21. In this case, the height of the wafer chuck 16 is known.

  Here, the configuration data is data such as setting parameters of various functions of the prober 10 and coordinate values of the mounting positions of mounted devices such as a microscope, and is stored in the HDD of the control unit 60 as unique data for each prober 10.

  For example, the configuration data includes a height dimension from the coordinate reference of the prober to the probe card mounting surface.

  The product type parameter is data in which product specifications such as the size and arrangement of the product wafer W and chips on the product wafer W are recorded. The product type parameter is data arbitrarily created by the user and is normally stored in the HDD of the control unit 60.

  Further, since the probe card 24 is manufactured exclusively according to the specifications of the product wafer W, individual information of the probe card 24 is also included. For example, the product type parameter includes the height dimension from the substrate surface of the probe card 24 to the tip of the probe 25.

  The probe position detection camera 18 raised to the working distance height performs autofocus on the probe, detects the tip of the probe 25, and detects the height of the tip of the probe 25. Here, as a method of raising the probe position detection camera 18, a method of raising the probe position detection camera 18 little by little while continuing the detection of the probe 25 while performing autofocus on the probe position detection camera 18 is also conceivable. However, such a method of raising the probe position detection camera 18 little by little requires a long operation time and is not preferable from the viewpoint of throughput.

  FIG. 2B is a diagram illustrating an example of a case where a collision between the probe position detection camera 18 and the tip of the probe 25 occurs.

  If there is a mistake in the input of configuration data, product type parameters, etc., the control unit 60 cannot accurately calculate the distance A as described with reference to FIG. In the case shown in FIG. 2B, the distance between the tip of the probe 25 and the wafer chuck 16 should be calculated as the distance A as in FIG. (Distance B> Distance A) is erroneously calculated. The control unit 60 controls the height adjustment mechanism 21 based on the erroneously calculated distance B to raise the probe position detection camera 18 to the working distance height at a stroke, so that the probe position detection camera 18 is connected to the tip of the probe 25. It will collide. The collision between the probe position detection camera 18 and the probe 25 causes a problem that the probe 25 and the probe card 24 are damaged and the probe position detection camera 18 is damaged.

  According to one aspect of the present invention, the collision between the probe position detection camera 18 and the tip of the probe 25 as described in FIG. 2 can be prevented.

  Next, the detection of the height of the tip of the probe 25 using the probe height detector 20 according to the present invention will be described with reference to FIGS.

  FIG. 3 is a diagram illustrating detection of the tip of the probe 25 performed by the probe height detector 20.

  FIG. 3A is a diagram for explaining the detection of the height of the probe 25 by the probe height detector 20. When the probe position detection camera 18 focuses on the tip of the probe 25 or when it is raised to the working distance height, the probe height detector 20 first detects the position of the probe 25. Specifically, the probe height detector 20 is raised by the height adjustment mechanism 27 until it contacts the tip of the probe 25. The probe height detector 20 outputs a signal to the sensor mechanism 20b when contacting the probe 25 with the contact surface 20a. The sensor mechanism 20b outputs the signal output from the contact surface 20a and the height adjustment mechanism 27. Information on the height of the tip of the probe 25 is transmitted to the control unit 60 based on the signal indicating the height (see FIG. 4).

  FIG. 4 is a diagram conceptually showing information input to the control unit 60 and information output from the control unit 60 together with functional blocks.

  As shown in FIG. 4, information related to the height of the tip of the probe 25 that is an actual measurement value of the probe height detector 20 is input to the control unit 60. The control unit 60 receives configuration data and product parameters input by the user via the input unit 62, and the control unit 60 uses the input configuration data and product parameters to input the tips of the wafer chuck 16 and the probe 25. And the distance is calculated.

  Thereafter, the control unit 60 compares the height of the probe 25 detected by the probe height detector 20 with the height of the probe 25 calculated from the configuration data and the product type parameter. Then, the control unit 60 outputs a command for changing the height of the probe position detection camera 18 from the reference plane to the height adjustment mechanism 21 based on the comparison result. The control unit 60 can use various methods for comparing the height of the probe 25 calculated from the configuration data and the product type parameter and the height of the probe 25 detected by the probe height detector 20. For example, using the threshold value, the control unit 60 may determine that the heights match if they are within the threshold value range, and may determine that the heights do not match if they are outside the threshold value range.

  When the height of the probe 25 calculated from the configuration data, the product type parameter, and the like is the same as the height of the probe 25 detected by the probe height detector 20, the control unit 60 receives the input configuration data. Judge that the product parameters were correct. For example, as shown in FIGS. 3A and 3B, the control unit 60 uses the distance A from the reference surface (the upper surface of the wafer chuck 16) detected by the probe height detector 20, the configuration data, the product parameters, and the like. The distance B, which is the calculated height of the probe 25, is compared, and it is determined that it is B (nearly equal) A. Thereafter, as shown in FIG. 3B, the control unit 60 outputs a command for the probe position detection camera 18 to raise the working distance to the height adjustment mechanism 21 at a stroke, and the probe position detection camera 18 performs autofocus and performs the probe operation. 25 tips are detected. That is, the probe position detection camera 18 is driven up and down in the Z-axis direction based on the height of the tip of the probe 25 detected by the probe height detector 20 and moved to the working distance height.

  On the other hand, when the height of the probe 25 set by the configuration data, the product type parameter, and the like is not the same as the height of the probe 25 acquired by the probe height detector 20, the control unit 60 receives the input configuration data. If it is determined that the product type parameter or the like is wrong, an error is displayed on the display unit 61 to notify the user, and the operation of the prober 10 is stopped. Thereby, the collision between the probe 25 and the probe position detection camera 18 described with reference to FIG. 2B can be prevented.

  As another aspect, when the control unit 60 determines that the input configuration data or product type parameter is incorrect, the height of the probe 25 acquired by the probe height detector 20 instead of the input value. Using this, the probe position detection camera 18 may be raised to the working distance height. Thereby, even if the input configuration data and product type parameters are incorrect, measurement can be continued without stopping the prober 10.

  FIG. 5 is a flowchart showing a method for operating the prober 10. In the operation method shown in FIG. 5, the probe tip height calculated from the configuration data and the product type parameter is determined based on the height of the probe 25 detected by the probe height detector 20.

  First, the user inputs configuration data and product type parameters to the control unit 60 via the input unit 62. Thereafter, the control unit 60 calculates the height of the tip of the probe 25 based on the input configuration data and product type parameters (step S10). Next, the height of the probe 25 is detected by the probe height detector 20 (step S11). Specifically, the probe height detector 20 is raised by the height adjustment mechanism 27 and contacts the probe 25 to detect the height of the probe 25.

  Then, the control unit 60 compares the height of the tip of the probe 25 calculated based on the configuration data and the product type parameter with the height of the tip of the probe 25 actually detected by the probe height detector 20. If the two do not match, the control unit 60 causes the display unit 61 to display a warning indicating an error (step S14).

  On the other hand, when the two match, the control unit 60 outputs a command to raise the probe position detection camera 18 to the working distance height to the height adjustment mechanism 21. Thereafter, the probe position detection camera 18 is raised to the working distance height based on the command (step S13).

  FIG. 6 is a flowchart showing another operation method of the prober 10. In the other operation method shown in FIG. 6, the probe position is not calculated based on the configuration data or product type parameters, but based on the probe height detected by the probe height detector 20 without calculating the height of the probe 25. The detection camera 18 is raised.

  First, the height of the probe 25 is detected by the probe height detector 20 (step S20). Specifically, the probe height detector 20 is raised by the height adjustment mechanism 27 and contacts the probe 25 to detect the height of the tip of the probe 25. Based on the detected height of the tip of the probe 25, the control unit 60 calculates a height (working distance height) that is away from the working distance of the probe position detection camera 18 from the tip of the probe 25. A command is output to the adjustment mechanism 21 (step S21).

  Thereafter, the height of the probe position detection camera 18 is changed to the working distance height based on the height of the tip of the probe 25 detected by the probe height detector 20 (step S22). As shown in FIG. 6, the height of the tip of the probe 25 detected by the probe height detector 20 is used without calculating the height of the tip of the probe 25 by inputting configuration data and product type parameters. May be.

  Each of the above-described configurations and functions can be appropriately realized by arbitrary hardware, software, or a combination of both. For example, for a program that causes a computer to execute the above-described processing steps (processing procedure), a computer-readable recording medium (non-transitory recording medium) that records such a program, or a computer that can install such a program However, the present invention can be applied.

<Second Embodiment>
Next, a second embodiment will be described.

  FIG. 7 is a schematic configuration diagram showing a second embodiment of a wafer test system 100 to which the present invention is applied. In addition, the part already demonstrated in FIG. 1 attaches | subjects the same code | symbol, and abbreviate | omits description.

  The prober 10 shown in FIG. 7 differs from the prober 10 shown in FIG. 1 in that a probe height detector 20 is provided integrally with the probe position detection camera 18.

  The probe height detector 20 is provided integrally with the probe position detection camera 18, and the height is adjusted by the height adjustment mechanism 21 of the probe position detection camera 18. That is, since the probe height detector 20 and the probe position detection camera 18 are integrally provided via the arm 29, the height can be adjusted by a single height adjustment mechanism, so that the height adjustment is controlled. Is more simplified. Further, since one installation of the height adjusting mechanism can be omitted, the design and assembly of the prober 10 are simplified. Further, since the probe height detector 20 is provided integrally with the probe position detection camera 18, the probe height detector 20 is suppressed from the influence of temperature. In other words, since the temperature change of the probe position detection camera 18 is generally small, the probe height detector 20 is provided integrally with the probe position detection camera 18 so that the influence of the temperature change is suppressed. On the other hand, for example, when the probe position detection camera 18 is provided on the wafer chuck 16, since the temperature change of the wafer chuck 16 is −60 ° C. to 200 ° C., the probe height detector 20 is easily affected by the temperature change.

  The probe height detector 20 is provided integrally with the probe position detection camera 18 by a known technique. In FIG. 7, the probe height detector 20 is provided on the side of the probe position detection camera 18 by the arm 29, but may be attached by other means.

  FIG. 8 is a diagram illustrating detection of the tip of the probe 25 that is performed when the probe height detector 20 and the probe position detection camera 18 are provided integrally.

  As shown in FIG. 8A, when the probe height detector 20 is provided integrally with the probe position detection camera 18, the height of the contact surface 20a of the probe height detector 20 is determined by the probe position detection camera. It is preferable to be provided at a position higher than the height of the end of the 18 objective lenses 18a. Thus, the tip of the probe 25 can be detected by the contact surface 20a of the probe height detector 20 before the probe 25 collides with the objective lens 18a of the probe position detection camera 18. Further, the contact surface 20a of the probe height detector 20 is provided at a position lower than the height obtained by adding the working distance to the height of the probe position detection camera 18. This does not prevent the probe position detection camera 18 from performing autofocus and detecting the tip of the probe 25.

  FIG. 8B is a diagram showing the measurement of the height of the tip of the probe 25 by the probe height detector 20. The probe height detector 20 is provided integrally with the probe position detection camera 18 and is driven up and down by the height adjustment mechanism 21 of the probe position detection camera 18 to measure the height of the tip of the probe 25.

  FIG. 8C shows the probe position detection camera 18 moved to the working distance height. The probe position detection camera 18 is moved to the working distance height by the height adjusting mechanism 21 based on the height of the tip of the probe 25 detected by the probe height detector 20. Here, since the height relationship between the probe position detection camera 18 and the probe height detector 20 is integrally provided and does not change, the control unit 60 determines the probe 25 detected by the probe height detector 20. The height of the probe position detection camera 18 can be easily controlled according to the height of the tip. Furthermore, since the distance between the contact surface 20a of the probe height detector 20 and the objective lens 18a of the probe position detection camera 18 is provided integrally, the Z-axis direction, the X-axis direction, and the Y-axis direction (see FIG. 7). ) Is extremely short. Accordingly, the movement time for focusing the probe position detection camera 18 on the tip of the probe 25 after detecting the tip of the probe 25 on the contact surface 20a of the probe height detector 20 can be shortened.

<Application example of probe tip height detection>
Next, an aspect in which the detection of the height of the tip of the probe 25 described above is applied will be described.

  The detection of the height of the tip of the probe 25 can be applied to various modes. In particular, it can be suitably applied to an embodiment that requires an accurate height of the tip of the probe 25. For example, the height detection of the tip of the probe 25 described above can be applied to the detection of the inclination of the probe card 24 of the probe 25.

  FIG. 9 is a diagram illustrating a card holder 23 or a method of detecting the inclination of the probe card 24 installed in the card holder 23 that is generally performed conventionally. In the case shown in FIG. 9, the parallelism confirmation jig 70 is set in the card holder 23 instead of the probe card 24 to detect the inclination of the card holder 23. Specifically, the inclination of the card holder 23 is detected by detecting the height of the surface of the parallelism confirmation jig 70 set in the card holder 23 by the probe position detection camera 18 a plurality of times.

  If the probe position detection camera 18 tries to detect the tip of the probe 25 of the probe card 24, it takes time to detect the probe tip, and the throughput of the prober 10 decreases. Therefore, when the parallelism confirmation jig 70 is used in place of the probe card 24, the parallelism confirmation jig 70 has a flat surface, so that the probe position detection camera 18 can be focused in a relatively short time. . The parallelism confirmation jig 70 is a metal plate processed to resemble the probe card 24, for example.

  However, if the inclination of the card holder 23 is detected using the parallelism confirmation jig 70, the processing accuracy of the parallelism confirmation jig 70 affects the precision of inclination detection. In addition, after the inclination detection by the parallelism confirmation jig 70 is completed, the probe card 24 must be set in the card holder 23, resulting in a decrease in throughput.

  Therefore, in this example, the inclination of the card holder 23 (or probe card 24) used for the probe card 24 is detected by applying the detection of the height of the tip of the probe 25 using the probe height detector 20 described above. Do.

  10 and 11 are diagrams for explaining the inclination detection of the card holder 23 or the probe card 24 of this example. In FIG. 10, the probe height detector 20 detects the inclination of the probe card 24 set in the card holder 23.

  The probe height detector 20 is provided integrally with the probe position detection camera 18 and is driven up and down by a height adjustment mechanism 21 of the probe position detection camera 18, and comes into contact with the tip of the probe 25 to contact the probe 25. The height of the tip is detected.

  FIG. 11 is a diagram conceptually showing information input to the control unit 60 and information output from the control unit 60 together with functional blocks.

  As shown in FIG. 11, a plurality of pieces of information regarding the height of the tip of the probe 25 obtained by actual measurement from the probe height detector 20 are input to the control unit 60. Here, the plurality of heights of the tips of the probes 25 are input in order to calculate the inclination of the probe card 24 or the inclination of the card holder 23. Therefore, for example, the probe height detector 20 transmits the heights of the tips of the three different probes 25 to the control unit, and the control unit 60 outputs the inclination of the probe card 24. In the present application, the tilt adjustment mechanism that adjusts the tilt based on the detected tilt is not described, but the tilt may be adjusted based on the tilt detected by a known tilt adjustment mechanism.

  Next, an example in which the inclination of the probe card 24 is detected also by the probe position detection camera 18 in the application example described above will be described.

  In FIG. 12, the probe position detection camera 18 detects the tilt of the probe card 24. In this case, the probe position detection camera 18 detects the height of the tip of the probe 25 based on the height of the tip of the probe 25 detected by the probe height detector 20. That is, as described with reference to FIGS. 3 and 8, the probe position detection camera 18 uses the height adjustment mechanism 21 to adjust the working distance height based on the height of the tip of the probe 25 detected by the probe height detector 20. Then, the height of the tip of the probe 25 is detected. Similarly to the probe height detector 20 described above, the probe position detection camera 18 detects the height of the tip of the probe 25 at a plurality of different points, and the control unit 60 detects the height of the detected tip of the probe 25. Based on this, the inclination of the probe card 24 is detected.

  Thus, in this example, the inclination of the probe card 24 is detected based on the height of the tip of the probe 25 output from the probe height detector 20 and the probe position detection camera 18.

  FIG. 13 is a flowchart showing a procedure for detecting the inclination of the probe card 24 (card holder 23) of this example. FIG. 13 shows an example in which the tip height of the probe 25 is detected by the probe height detector 20 and the probe position detection camera 18 to detect the inclination.

  First, the height of the tip of the probe 25 is measured a plurality of times by the probe height detector 20, and the measurement result is transmitted to the control unit 60 (first height detection step: step S30). Multiple measurements are performed at different points, and the probe height detector 20 moves in the X-axis direction and the Y-axis direction to measure the height of the tip of the probe 25.

  Next, the probe position detection camera 18 measures a plurality of heights of the tip of the probe 25 and transmits the measurement result to the control unit 60 (second height detection step: step S31). Similar to the probe height detector 20, the probe position detection camera 18 also detects the height of the tip of the probe 25 at a plurality of different points. Here, the probe position detection camera 18 is moved to the working distance height based on the height of the tip of the probe 25 detected in advance by the probe height detector 20 and performs autofocus on the tip of the probe 25. Therefore, since the time for searching for the tip of the probe 25 of the probe position detection camera 18 can be shortened, a decrease in the throughput of the prober 10 is suppressed.

  Thereafter, the control unit 60 calculates the inclination of the probe card 24 based on the heights of the tips of the plurality of probes 25 output from the probe height detector 20 and the probe position detection camera 18 (inclination detection step: step S32). ). Here, the control unit 60 detects the tilt based on the height of the tip of the probe 25 detected by the probe height detector 20, and then the height of the tip of the probe 25 detected by the probe position detection camera 18. The inclination is detected based on the above. Since the control unit 60 detects the tilt using the detection result of the probe position detection camera 18 that can detect the height of the tip of the probe 25 with higher accuracy, the control unit 60 can detect the tilt more accurately.

<Probe height detector of another embodiment>
FIG. 14 is an explanatory diagram for explaining a probe height detector 100 according to another embodiment. As shown in FIG. 14, the probe height detector 100 of another embodiment uses a LVDT 106 that is a linear variable differential transformer, and the height of the tip of the probe 25 from the reference plane described above. Detect. The probe height detector 100 includes a base 102, an air bearing 103, a vertically movable portion 104, a coil spring 105, and an LVDT 106.

  The base 102 is supported above the height adjustment mechanism 27 by a support member (not shown). The base 102 is formed in a substantially annular shape, and a through hole 102 a parallel to the Z-axis direction (vertical direction) is formed at the center of the base 102. An air bearing 103 is provided on the upper surface of the base 102.

  The air bearing 103 is formed in a substantially cylindrical shape and has a holding hole 103a parallel to the Z-axis direction. The position of the center of the holding hole 103a in the XY axis direction and the position of the center of the through hole 102a described above in the XY axis direction coincide with each other. Reference symbol C is a central axis passing through the centers of both the holding hole 103a and the through hole 102a. The air bearing 103 holds an up-and-down moving shaft 110 of an up-and-down movable unit 104 (described later) inserted through the holding hole 103a so as to be movable in the Z-axis direction.

  The air bearing 103 is formed with an air supply hole (not shown) penetrating from the outer peripheral surface to the inner surface of the holding hole 103a, and air supplied from an air source (not shown) through the air supply hole is provided. It is supplied into the holding hole 103a. As a result, an air layer (not shown) is formed between the inner surface of the holding hole 103a and the outer surface of the vertical movement shaft 110, so that the vertical movement shaft 110 is guided in a non-contact manner by the air bearing 103 (holding hole 103a). .

  Further, an annular flange 103b is formed on the outer peripheral surface of the lower end portion of the air bearing 103 along the circumferential direction.

  The vertically movable portion 104 is held by the air bearing 103 so as to be movable in the Z-axis direction without contact. The vertically movable portion 104 includes a vertically moving shaft 110, a stopper ring 111, a spring receiving portion 112, a stage base 113, and a stage 114.

  As described above, the vertical movement shaft 110 is inserted into the holding hole 103a of the air bearing 103 and is held by the air bearing 103 so as to be movable in the Z-axis direction without contact. A substantially annular stopper ring 111 is fitted on the lower end of the outer peripheral surface of the vertical movement shaft 110. A spring receiving portion 112 is fixed to the upper surface of the vertical movement shaft 110.

  The outer diameter of the stopper ring 111 is formed larger than the diameter of the holding hole 103a. The spring receiving portion 112 includes a disc portion 112a and a fitting portion 112b provided on the lower surface of the disc portion 112a. The outer diameter of the disc part 112 a is formed larger than the outer diameter of the coil spring 105. The fitting portion 112 b is fitted into the opening on the upper side of the coil spring 105.

  The stage pedestal 113 is fixed to the upper surface of the spring receiving portion 112. A stage 114 is fixed to the upper surface of the stage base 113. The upper surface of the stage 114 becomes the contact surface 20a described above.

  The coil spring 105 is attached between the flange portion 103b and the spring receiving portion 112 in a state compressed in the Z-axis direction. The upper end of the air bearing 103 described above is inserted into the lower opening of the coil spring 105. Thereby, the lower end of the coil spring 105 contacts the upper surface of the flange 103b. On the other hand, the above-described fitting portion 112 b is fitted into the upper opening of the coil spring 105. For this reason, the coil spring 105 urges each part (the stage 114 and the like) of the up and down movable part 104 upward in the Z-axis direction via the spring receiving part 112. As a result, the stopper ring 111 contacts the lower opening edge of the holding hole 103a, and the height position of the stage 114 in the Z-axis direction is kept constant.

  The LVDT 106 is provided on the lower surface of the base 102. The LVDT 106 includes a core 106a such as an iron core and a coil 106b. The core 106a is fixed to the lower surface of the vertical movement shaft 110 and extends downward in the Z-axis direction. The central axis of the core 106a coincides with the above-described central axis C. The core 106a moves in the Z-axis direction integrally with the vertical movement shaft 110 (the vertical movable portion 104).

  The coil 106b has a substantially cylindrical shape parallel to the Z-axis direction. The core 106a is inserted in the coil 106b in a non-contact manner. The coil 106b has a primary coil (not shown) excited by an input voltage (alternating current) and a secondary coil (not shown) that generates an output voltage (induced voltage) due to the displacement of the core 106a in the Z-axis direction. doing.

  The minute movement detection unit 118 supplies an input voltage to the coil 106b and detects an output voltage output from the coil 106b according to the displacement of the core 106a in the Z-axis direction. The minute movement detection unit 118 detects minute movements in the Z-axis direction of the core 106a, that is, the vertically movable unit 104 (the stage 114, etc.), based on the output voltage output from the coil 106b.

  According to the probe height detector 100 having the above configuration, the height adjustment mechanism 27 moves the probe height detector 100 upward in the Z-axis direction, so that the contact surface 20a of the stage 114 contacts the tip of the probe 25. Then, the vertically movable unit 104 (the stage 114 and the like) and the core 106a are slightly moved downward in the Z-axis direction. As a result, the output voltage output from the coil 106b according to the minute movement of the core 106a is input to the minute movement detection unit 118. Therefore, the minute movement detection unit 118 can detect minute movement in the Z-axis direction of the vertically movable unit 104 (the stage 114 and the like), that is, contact of the tip of the probe 25 with the contact surface 20a. Since the subsequent steps are the same as the probe height detector 20 described above, a detailed description thereof will be omitted.

  Thus, since the probe height detector 100 detects the contact of the tip of the probe 25 with the contact surface 20a using the LVDT 106, the detection accuracy [contact responsiveness (sensitivity)] of the contact can be improved. it can. As a result, it is possible to improve the measurement accuracy of the height of the tip of the probe 25 from the above-described reference plane. Further, the amount of movement (pushing amount) in the Z-axis direction of the stage 114 and the like accompanying the contact of the tip of the probe 25 with the contact surface 20a and the pressing force in the Z-axis direction accompanying the contact can be detected with high accuracy.

  The example of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Prober 11 ... Base 12 ... Movement base 13 ... Y-axis movement stand 14 ... X-axis movement stand 15 ... Rotation part 16 ... Wafer chuck 18 ... Probe position detection camera 18a ... Objective lens 19 ... Wafer alignment camera 20, 100 ... Probe height detector 20a ... contact surface 20b ... sensor mechanism 21 ... height adjustment mechanism 22 ... head stage 23 ... card holder 24 ... probe card 25 ... probe 27 ... height adjustment mechanism 29 ... arm 30 ... tester 31 ... tester body 32 ... Contact ring 60 ... Control unit 61 ... Display unit 62 ... Input unit 100 ... Wafer test system 106 ... Linear variable differential transformer (LVDT)

Claims (4)

A prober that performs an inspection by bringing a probe into contact with an electrode of a wafer arranged to face the probe,
A probe position detection camera that detects a tip position of the probe at a position facing the probe;
A probe height detector that is provided separately from the probe position detection camera and detects the height position of the tip of the probe at a position facing the probe;
Prober with.   The prober according to claim 1, wherein the probe height detector includes a differential transformer that detects contact of a tip of the probe.   The prober according to claim 1, wherein the probe height detector is provided integrally with the probe position detection camera. The probe height detector is provided independently of the probe position detection camera,
4. The prober according to claim 1, further comprising a second height adjustment mechanism that changes a height of the probe height detector from a predetermined reference plane. 5.

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