Prober and method for controlling same

Abstract

To provide a prober capable of preventing a drop in vacuum pressure for vacuum adsorption of a probe card, and a control method therefor.SOLUTION: A prober (1) includes a probe card (14) having a probe for inspecting a wafer, a probe card suction unit (18) to which the probe card is adsorbed, a first vacuum source (VC1) which is connected to the probe card suction unit via a first vacuum suction line for adsorbing and holding the probe card to the probe card suction unit, a second vacuum source (VC2) which is connected to the probe card suction unit via a second vacuum suction line for adsorbing and holding the probe card to the probe card suction unit, backflow prevention means (C6 to C10) provided in the second vacuum suction line, and a control device (40) for switching to suction by the first vacuum source after the probe card is adsorbed to the probe card suction unit by the second vacuum source.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a prober and a control method thereof, and more particularly to a prober for inspecting a plurality of semiconductor devices formed on a semiconductor wafer and a control method thereof.

Background Art

[0002] In the manufacturing process of semiconductor devices, various inspections are performed in various manufacturing processes in order to ensure quality and improve yield. For example, in wafer-level inspection, when a plurality of chips corresponding to individual semiconductor devices are formed on a semiconductor wafer (hereinafter referred to as a wafer), the electrodes (pads) of the semiconductor devices are connected to a tester, and a test signal is supplied. Then, the signal output by the semiconductor device in response to this test signal is measured by the tester, and it is electrically inspected whether the semiconductor device operates normally.

[0003] With the recent progress in miniaturization and high integration of semiconductor devices, the electrodes on the wafer have been miniaturized, and the number of chips formed on a single wafer has become very large. Along with this, the time required for inspecting a single wafer with a prober has become longer, and an improvement in throughput is required. Therefore, in order to improve throughput, a multi-stage prober in which a large number of probes are arranged in multiple stages to simultaneously inspect a plurality of chips is known (see Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] A multi-stage type prober is equipped with multiple measurement units (measurement sections), and a probe card is attracted and held on a head stage provided in each measurement unit, and wafer-level inspection is performed on a wafer placed on a wafer chuck.

[0006] FIG. 12 shows an example in which the probe cards 14-1 to 14-5 in five measuring units SU1 to SU5 are vacuum-sucked by one vacuum source VC10. In the example shown in FIG. 12, a vacuum suction line L20 extending from one vacuum source VC10 is connected to the head stages 18-1 to 18-5 of the measuring units SU1 to SU5 via vacuum suction lines L20-1 to L20-5, respectively. In this case, when checking the presence of the probe cards before suctioning them, empty suction may occur in any of the vacuum suction lines L20-1 to L20-5. When such empty suction occurs, the vacuum pressure decreases in the entire vacuum suction lines (L20 and L20-1 to L20-5), and the probe cards (14-1 to 14-5) may fall off the head stages (18-1 to 18-5).

[0007] In order to prevent such a drop in vacuum pressure caused by dry suction, it is conceivable to provide vacuum sources VC11 to VC15 for suctioning the probe cards 14-1 to 14-5 for each of the measurement units SU1 to SU5, as shown in FIG.

[0008] However, as shown in FIG. 13, when the measurement units SU1 to SU5 are provided with their own vacuum sources VC11 to VC15, respectively, there is a problem that the costs (facility costs, etc.) for installing, operating and maintaining the prober increase.

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a prober capable of preventing a drop in the vacuum pressure for vacuum suction of a probe card, and a method for controlling the same. [Means for solving the problem]

[0010] In order to solve the above problems, a prober according to a first aspect of the present invention comprises a probe card having a probe for inspecting a wafer, a probe card suction unit to which the probe card is adsorbed, a first vacuum source connected to the probe card suction unit via a first vacuum suction line for adsorbing and holding the probe card on the probe card suction unit, a second vacuum source connected to the probe card suction unit via a second vacuum suction line for adsorbing and holding the probe card on the probe card suction unit, a backflow prevention means provided on the second vacuum suction line, and a control device that switches suction to the first vacuum source after the probe card is adsorbed to the probe card suction unit by the second vacuum source.

[0011] A prober according to a second aspect of the present invention is the same as that of the first aspect, and is equipped with a pressure sensor for detecting the suction state of the probe card, and a control device uses a second vacuum source to suction the probe card to the probe card suction unit, and when the suction state becomes a normal suction state, switches to suction using the first vacuum source.

[0012] In a prober according to a third aspect of the present invention, in the second aspect, when switching from suction by the second vacuum source to suction by the first vacuum source, the control device starts suction by the first vacuum source while maintaining suction by the second vacuum source, then stops suction by the second vacuum source and switches to suction by only the first vacuum source.

[0013] A prober according to a fourth aspect of the present invention is the prober of the second or third aspect, in which the first vacuum suction line and the second vacuum suction line are connected to the probe card suction unit via a common vacuum suction line, and the pressure sensor is provided on the common vacuum suction line.

[0014] A prober according to a fifth aspect of the present invention, in any of the first to fourth aspects, comprises a first solenoid valve provided in the first vacuum suction line and a second solenoid valve provided in the second vacuum suction line, and the control device adsorbs the probe card to the probe card suction unit using the second vacuum source by putting the first solenoid valve in a blocked state and the second solenoid valve in a connected state, and switches to suction using the first vacuum source by putting the second solenoid valve in a blocked state and the first solenoid valve in a connected state.

[0015] A sixth aspect of the present invention relates to a method for controlling a prober comprising a first vacuum source connected to a probe card suction unit via a first vacuum suction line for adsorbing and holding a probe card on the probe card suction unit, and a second vacuum source connected to the probe card suction unit via a second vacuum suction line provided with a backflow prevention means for adsorbing and holding the probe card on the probe card suction unit, the method including the steps of adsorbing the probe card to the probe card suction unit using the second vacuum source, and switching to adsorption using the first vacuum source after adsorbing the probe card to the probe card suction unit using the second vacuum source.

[0016] A prober control method according to a seventh aspect of the present invention, in the sixth aspect, includes the steps of adsorbing the probe card to the probe card suction unit using a second vacuum source, and after suction by the second vacuum source, detecting an suction state of the probe card based on output from a pressure sensor, and switching to suction by the first vacuum source when the suction state becomes a normal suction state. Effect of the Invention

[0017] According to the present invention, by using a second vacuum suction line equipped with a backflow prevention means, it is possible to normally suction and hold the probe card even if dry suction occurs and the vacuum pressure drops. [Brief description of the drawings]

[0018] [Figure 1]FIG. 1 is a block diagram showing a suction mechanism in a multi-stage prober according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a block diagram showing a suction mechanism in a multi-stage prober according to an embodiment of the present invention. [Diagram 3] FIG. 3 is a schematic diagram showing a form of a backflow prevention means according to one embodiment of the present invention. [Figure 4] FIG. 4 is a front view showing a measurement unit of a prober according to an embodiment of the present invention. [Diagram 5] FIG. 5 is a block diagram (partial cross-sectional view) illustrating the configuration for adsorbing a probe card in the measurement unit. [Figure 6] FIG. 6 is a block diagram (partial cross-sectional view) showing the adsorption state of the probe card (normal adsorption state). [Figure 7] FIG. 7 is a block diagram (partial cross-sectional view) showing the state of suction of the probe card (incomplete suction state). [Figure 8] FIG. 8 is a block diagram (partial cross-sectional view) showing the state in which a probe card is adsorbed (without the card). [Figure 9] FIG. 9 is a table showing an example of measurement values ​​by the pressure sensor and threshold values. [Figure 10] FIG. 10 is a flowchart showing a method of controlling a prober (when a probe card is mounted) according to an embodiment of the present invention. [Figure 11] FIG. 11 is a flowchart showing a method of controlling a prober (when checking the state of a probe card) according to an embodiment of the present invention. [Figure 12] FIG. 12 is a block diagram showing an example of a vacuum source in a multi-stage prober. [Figure 13] FIG. 13 is a block diagram showing an example of a vacuum source in a multi-stage prober. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a prober and a control method thereof according to the present invention will be described with reference to the accompanying drawings.

[0020] [Prober suction mechanism] FIG. 1 is a block diagram showing a suction mechanism in a multi-stage prober according to an embodiment of the present invention.

[0021] 1, the prober 1 according to this embodiment includes a plurality of (five in this embodiment) measuring units SU1 to SU5. The measuring units SU1 to SU5 are provided with probe card suction units (head stages) 18-1 to 18-5, respectively, and the probe cards 14-1 to 14-5 are suction-held by the head stages 18-1 to 18-5, respectively.

[0022] The prober 1 according to this embodiment includes two vacuum sources, a first vacuum source VC1 and a second vacuum source VC2 (hereinafter, the "first vacuum source VC1" and the "second vacuum source VC2" are simply referred to as the "vacuum source VC1" and the "vacuum source VC2", respectively) as a suction mechanism 100 for suctioning and holding the probe cards 14-1 to 14-5 on the head stages 18-1 to 18-5. The vacuum sources VC1 and VC2 are mutually independent vacuum sources, and are, for example, a vacuum source, a vacuum pump, an ejector, or the like, of a factory or the like in which the prober is installed.

[0023] The vacuum source VC1 is connected to the head stages 18-1 to 18-5 via vacuum suction lines L1-1 to L1-5, respectively. The vacuum source VC1 functions as a main vacuum for suction-holding the probe cards 14-1 to 14-5 on the head stages 18-1 to 18-5, respectively.

[0024] The vacuum source VC2 is connected to the head stages 18-1 to 18-5 via vacuum suction lines L2-1 to L2-5, respectively. The vacuum source VC2 functions as a sub-vacuum for suction-holding the probe cards 14-1 to 14-5 on the head stages 18-1 to 18-5, respectively.

[0025] In this embodiment, the process from checking the presence of the probe cards (14-1 to 14-5) to adsorption to the head stages (18-1 to 18-5) is performed by the vacuum source VC2 functioning as a sub-vacuum. Here, the presence check refers to checking whether the probe cards (14-1 to 14-5) are loaded into the measurement units (SU1 to SU5). After checking the adsorption state of the probe cards (14-1 to 14-5), the vacuum source is switched to the vacuum source VC1 functioning as the main vacuum.

[0026] The vacuum suction lines (L2-1 to L2-5) connected to the vacuum source VC2 are provided with check valves (C6 to C10 in FIG. 2) as backflow prevention means. In this embodiment, the process from the presence check to the suction to the head stages (18-1 to 18-5) is performed via the vacuum suction lines (L2-1 to L2-5) provided with the check valves (C6 to C10), thereby preventing a drop in the vacuum pressure in the vacuum suction line L1 due to empty suction during the presence check.

[0027] The configurations of the vacuum sources VC1 and VC2 and the vacuum suction lines (L1, L2, etc.) will be described below.

[0028] As shown in Fig. 1, vacuum sources VC1 and VC2 are connected to vacuum suction lines L1 and L2, respectively. Vacuum suction line L1 branches into vacuum suction lines L1A and L1B, and vacuum suction line L1B is connected to vacuum suction lines L1-1 to L1-5 and L3-1 to L3-5. Meanwhile, vacuum suction line L2 is connected to vacuum suction lines L2-1 to L2-5.

[0029] The vacuum source VC1 is connected to a loader unit (not shown) of the prober 1 through a vacuum suction line L1A. This vacuum source VC1 makes it possible to suction the wafer W to a wafer transport arm inside the loader unit and transport it. The vacuum suction line L1A may be provided with an electromagnetic valve for performing and releasing the suction of the wafer W to the wafer transport arm, and a pressure sensor for detecting the suction state of the wafer W (neither of which are shown).

[0030] The vacuum source VC1 is also connected to the prober components provided in each of the measurement units SU1 to SU5 via the vacuum suction lines L1B and L3-1 to L3-5. Here, the prober components are, for example, cleaning units (units for removing adhesions such as shavings attached to the probe 16) provided inside each of the measurement units SU1 to SU5. Each of the vacuum suction lines L3-1 to L3-5 may be provided with an electromagnetic valve for starting and stopping suction by the cleaning unit, and a pressure sensor for detecting the state of the cleaning unit (suction, reduction in suction force, and stop) (both not shown).

[0031] Vacuum source VC1 is connected to head stages 18-1 to 18-5 provided in each measurement unit SU1 to SU5 via vacuum suction lines L1B and L1-1 to L1-5, and generates a vacuum pressure for adsorbing probe cards 14-1 to 14-5 to head stages 18-1 to 18-5, respectively.

[0032] The vacuum source VC2 is connected to the head stages 18-1 to 18-5 provided in each of the measurement units SU1 to SU5 via vacuum suction lines L2 and L2-1 to L2-5, and generates a vacuum pressure for adsorbing the probe cards 14-1 to 14-5 to the head stages 18-1 to 18-5, respectively.

[0033] FIG. 2 is a block diagram showing a suction mechanism in a multi-stage prober according to an embodiment of the present invention.

[0034] As shown in FIG. 2, a pressure sensor S1 and a vacuum regulator R1 are provided on the vacuum suction line L1B on the main vacuum (vacuum source VC1) side.

[0035] The pressure sensor S1 detects the pressure in the vacuum suction line L1B and outputs it to the control device (reference numeral 40 in FIG. 4) of the probe 1. Based on the measured value by the pressure sensor S1, the control device 40 can detect the operating status of the vacuum source VC1 and the vacuum level in the vacuum suction line L1B.

[0036] The vacuum regulator (vacuum pressure regulating valve or pressure reducing valve) R1 adjusts the vacuum level in the vacuum suction line L1B.

[0037] Connected to the vacuum suction line L1B are vacuum suction lines L1-1 to L1-5 provided corresponding to the respective measurement units SU1 to SU5. Electromagnetic valves V1 to V5 are provided in the vacuum suction lines L1-1 to L1-5 respectively.

[0038] The electromagnetic valves (first electromagnetic valves) V1 to V5 switch the communication state (hereinafter referred to as ON) and the cutoff state (hereinafter referred to as OFF) of the vacuum suction lines L1-1 to L1-5 respectively according to commands from the control device 40. When the electromagnetic valves V1 to V5 are ON, the probe cards 14-1 to 14-5 can be adsorbed to the head stages 18-1 to 18-5 by the main vacuum (vacuum source VC1) via the vacuum suction lines L1-1 to L1-5. On the other hand, when the electromagnetic valves V1 to V5 are OFF, the adsorption states of the probe cards 14-1 to 14-5 are released.

[0039] Also, as shown in FIG. 2, a pressure sensor S2 is provided in the vacuum suction line L2 on the sub-vacuum (vacuum source VC2) side.

[0040] The pressure sensor S2 detects the pressure in the vacuum suction line L2 and outputs it to the control device 40 of the probe 1. Based on the measured value by the pressure sensor S2, the control device 40 can detect the operating status of the vacuum source VC2 and the vacuum level in the vacuum suction line L2.

[0041] The vacuum suction line L2 is connected to vacuum suction lines L2-1 to L2-5 provided corresponding to each of the measurement units SU1 to SU5. In FIG. 2, for convenience of illustration, the vacuum suction lines L2-1 to L2-5 and the vacuum suction lines L1-1 to L1-5 are illustrated as separate lines, but in this embodiment, the vacuum suction lines L2-1 to L2-5 merge with the vacuum suction lines L1-1 to L1-5 on the suction side (merging position CP in FIG. 5), respectively, and connect to the head stages 18-1 to 18-5 via a common vacuum suction line (symbol L4 in FIG. 5) (see FIG. 1). The vacuum suction lines L2-1 to L2-5 are provided with solenoid valves V6 to V10 and check valves C6 to C10, respectively.

[0042] The solenoid valves (second solenoid valves) V6 to V10 switch between a connected state (hereinafter, ON) and a cut-off state (vacuum source VC2 side cut-off and measurement unit SU side open state (hereinafter, OFF)) of the vacuum suction lines L2-1 to L2-5, respectively, in response to a command from the control device 40. When the solenoid valves V6 to V10 are ON, the probe cards 14-1 to 14-5 can be sucked onto the head stages 18-1 to 18-5 by the sub-vacuum (vacuum source VC2) via the vacuum suction lines L2-1 to L2-5. On the other hand, when the solenoid valves V6 to V10 are OFF, the suction state of the probe cards 14-1 to 14-5 is released.

[0043] The check valves C6 to C10 limit the air flow in the vacuum suction lines L2-1 to L2-5 only in the direction from the suction side to the vacuum source VC2 side. By providing the check valves C6 to C10, it is possible to prevent the vacuum pressure on the vacuum source VC1 side from decreasing even if the vacuum pressure on the vacuum source VC2 side decreases due to dry suction or the like. This makes it possible to prevent the probe cards 14-1 to 14-5 from falling off due to a decrease in vacuum pressure.

[0044] In this embodiment, check valves C6 to C10 are provided in the vacuum suction lines L2-1 to L2-5 (see FIG. 3(A)), but the present invention is not limited to this, and the open ports of the solenoid valves V6 to V10 on the measurement unit suction side may be plugged (see FIG. 3(B)). In other words, any backflow prevention means is sufficient as long as it prevents air from flowing into the measurement unit suction side when the solenoid valves V6 to V10 are OFF. For example, as another form of backflow prevention means, two-port solenoid valves that can be turned ON and OFF may be used for the solenoid valves V6 to V10 (see FIG. 3(C)).

[0045] A threshold value of the vacuum pressure (gauge pressure) may be set for the pressure sensors S1 and S2. In this case, the pressure sensors S1 and S2 may output to the control device 40 whether or not the measured value of the vacuum pressure is higher than the threshold value. Here, when the measured value of the vacuum pressure is higher than the threshold value, the sensor may be in an ON state (vacuum state), and when the measured value of the vacuum pressure is lower than the threshold value, the sensor may be in an OFF state (non-vacuum state).

[0046] [Measurement unit] Next, the measurement units SU1 to SU5 will be described with reference to Fig. 4 etc. Fig. 4 is a front view showing a measurement unit of a prober according to one embodiment of the present invention. Note that since the measurement units SU1 to SU5 have substantially the same configuration, the subnumbers of the reference numerals of the respective parts will be omitted, and they will be described as a measurement unit SU, a probe card 14, a head stage 18, etc.

[0047] As shown in FIG. 4, the measurement unit SU includes a wafer chuck 12, a probe card 14, and a head stage 18.

[0048] The head stage 18 is supported by a frame member (not shown) that constitutes a part of the housing of the measurement unit SU, and the probe card 14 is detachably attached and fixed to the head stage 18. The probe card 14 attached and fixed to the head stage 18 is provided so as to face the wafer holding surface 12a of the wafer chuck 12. The probe card 14 is replaceable depending on the wafer W (device) to be inspected.

[0049] The probe card 14 is provided with a plurality of probes 16 in the form of cantilevers, spring pins, or the like, which are arranged corresponding to the positions of the electrode pads of each chip of the wafer W to be inspected. Each probe 16 is electrically connected to a terminal of a test head (not shown), and power and test signals are supplied from the test head to each chip via each probe 16, and the output signal from each chip is detected by the test head to measure whether it is operating normally.

[0050] The probe 16 has spring characteristics, and contacts the electrode pad with a predetermined contact pressure by raising the contact point from the tip of the probe 16. Furthermore, when the probe 16 contacts the electrode pad in an overdrive state during electrical testing, the tip of the probe 16 sinks into the surface of the electrode pad, leaving a needle mark on the surface of the electrode pad.

[0051] The wafer chuck 12 fixes the wafer W by vacuum suction. The wafer chuck 12 has a wafer holding surface 12a on which the wafer W to be inspected is placed, and the wafer holding surface 12a is provided with a plurality of suction ports 28. The suction ports 28 are connected to a vacuum source VC3 via a suction path 30 formed inside the wafer chuck 12. The vacuum source VC3 may also serve as the vacuum source VC1.

[0052] A heating / cooling mechanism (not shown) is provided inside the wafer chuck 12 as a heating / cooling source so that the electrical characteristics of the wafer W to be inspected can be inspected at a high temperature (e.g., up to 150° C.) or at a low temperature (e.g., down to −40° C.). As the heating / cooling mechanism, a heater, a device that circulates a thermal fluid, or a Peltier element can be used.

[0053] The wafer chuck 12 is supported and fixed by an alignment device 20. The alignment device 20 moves the wafer chuck 12 in the X, Y, Z, and θ directions to perform relative alignment between the wafer W held by the wafer chuck 12 and the probe card 14.

[0054] The alignment device 20 includes a Z stage (Z-axis moving / rotating part) 22 that supports and fixes the wafer chuck 12 and moves the wafer chuck 12 in the Z-axis direction and rotates in the θ direction around the Z axis as the center of rotation, an X carriage (X-axis moving base) 24 that supports the Z stage 22 and moves it in the X-axis direction, and a Y carriage (Y-axis moving base) 26 that supports the X carriage 24 and moves it in the Y-axis direction.

[0055] The Z stage 22, the X carriage 24, and the Y carriage 26 each include a mechanical drive mechanism including a motor, and are configured to move the wafer chuck 12 in the Z, X, and Y directions. Furthermore, the Z stage 22 is configured to rotate the wafer chuck 12 in the θ direction around the Z axis (a rotation axis parallel to the direction in which the probe card 14 and the wafer chuck 12 face each other). The mechanical drive mechanism may be, for example, a ball screw drive mechanism in which a servo motor and a ball screw are combined, or a linear motor drive mechanism or a belt drive mechanism. The Z stage 22, the X carriage 24, and the Y carriage 26 are configured so that the moving distance, moving direction, moving speed, and acceleration of the wafer chuck 12 can be changed by the control device 40.

[0056] The control device 40 comprehensively controls each component of the prober 1. The control device 40 can be realized by, for example, a general-purpose computer such as a personal computer or a workstation, and includes an operation unit and a display unit for receiving operation input. The control device 40 controls operations during wafer-level inspection using the probe card 14 (for example, suction of the wafer W to the wafer chuck 12 and release of the suction state, etc.).

[0057] FIG. 5 is a block diagram (partial cross-sectional view) illustrating the configuration for adsorbing the probe card 14-1 in the measuring unit SU1.

[0058] 5, the vacuum suction line L1-1 is connected to the head stage 18-1 of the measurement unit SU1 via an adapter 50. The vacuum suction line L2-1 merges with the vacuum suction line L1-1 on the head stage 18-1 (suction) side with respect to the solenoid valve V1 provided on the vacuum suction line L1-1.

[0059] Pressure sensors S3 and S4 are provided on the common vacuum suction line L4 on the head stage 18-1 (suction) side of the joining position CP of the vacuum suction lines L1-1 and L2-1. The pressure sensors S3 and S4 are set with different vacuum pressure (gauge pressure) thresholds, and the pressure sensor S3 is set with a threshold with a larger absolute value than the pressure sensor S4 (see FIG. 9). In the following description, the pressure sensors S3 and S4 are set in an ON state when the measured values ​​of the vacuum pressures are higher than their respective thresholds, and in an OFF state when the measured values ​​are lower than their respective thresholds. That is, when the pressure sensors S3 and S4 are both in the OFF state, the vacuum degree is low (hereinafter referred to as a low vacuum state), when the pressure sensors S3 and S4 are both in the ON state, the vacuum degree is high (hereinafter referred to as a high vacuum state), and when the pressure sensor S3 is in the OFF state and the pressure sensor S4 is in the ON state, the vacuum degree is intermediate between the low vacuum state and the high vacuum state (hereinafter referred to as a medium vacuum state).

[0060] Here, the vacuum suction lines L1B, L1-1 to L1-5 and the common vacuum suction line L4 according to this embodiment correspond to first vacuum suction lines, and the vacuum suction lines L2, L2-1 to L2-5 and the common vacuum suction line L4 correspond to second vacuum suction lines.

[0061] Next, a procedure for mounting (suctioning) the probe card 14-1 to the head stage 18-1 in the measuring unit SU1 will be described with reference to FIG.

[0062] First, before suctioning the probe card 14-1, the solenoid valve V6 is turned OFF (vacuum source VC2 side is shut off and measuring unit SU side is open) by the control device 40. Then, the control device 40 acquires the measured value of the vacuum pressure by the pressure sensor S3, and when the pressure sensor S3 is OFF (other than the high vacuum state), it determines that the probe card 14-1 is in an unloaded state and starts suctioning the probe card 14-1.

[0063] In this embodiment, the presence check is performed using the pressure sensor S3, but the presence check may be performed using the pressure sensor S4.

[0064] Next, the control device 40 turns off the solenoid valve V1 on the vacuum suction line L1-1 side and turns on the solenoid valve V6 on the vacuum suction line L2-1 side. This causes the probe card 14-1 to be attracted to the head stage 18-1 by the vacuum pressure from the sub-vacuum (vacuum source VC2).

[0065] When the probe card 14-1 is attracted to the head stage 18-1, the pressure in the common vacuum suction line L4 decreases (the vacuum pressure increases), and the pressure sensors S4 and S3 are turned on in sequence (high vacuum state). Note that when the probe card 14-1 is attracted, the solenoid valve V1 is closed, so the pressure on the vacuum source VC1 side of the vacuum suction line L1-1 (the value measured by the pressure sensor S1) does not change.

[0066] Next, the controller 40 turns on the solenoid valve V1 after the pressure sensor S3 turns on. Then, after a designated time has elapsed since the solenoid valve V1 turned on (since the vacuum pressure from the vacuum source VC1 has stabilized), the controller 40 turns off the solenoid valve V6. This switches from suction by the sub-vacuum (VC2) to suction by the main vacuum (VC1).

[0067] Next, the control device 40 acquires the measured values ​​by the pressure sensors S3 and S4 and judges the suction state of the probe card 14-1. If the pressure sensor S3 is in the ON state (see FIG. 6), the mounting process of the probe card 14-1 is normally completed.

[0068] 6 to 8 are block diagrams (partial cross-sectional views) showing the adsorption state of the probe card 14. Fig. 9 is a table showing examples of the measured values ​​and threshold values ​​by the pressure sensors S3 and S4.

[0069] 6 shows a state (normal suction state) in which the probe card 14 is normally suctioned to the head stage 18. In this case, both pressure sensors S3 and S4 are ON, the space between the probe card 14 and the receiving part 18A is maintained in a high vacuum state, and the suction force of the probe card 14 is sufficient (see example (1) in FIG. 9).

[0070] 7 shows a state in which the probe card 14 is not normally adsorbed to the head stage 18 (incomplete adsorption state). In this case, a gap is generated between the probe card 14 and the receiving part (e.g., annular packing, etc.) 18A of the head stage 18, and air (AIR) flows in through this gap. As a result, the vacuum pressure in the space between the probe card 14 and the receiving part 18A drops, and a medium vacuum state is created in which the pressure sensor S3 is OFF and the pressure sensor S4 is ON (see example (2) in FIG. 9).

[0071] 8 shows a state in which the probe card 14 is not held by the head stage 18 (state without card). In this case, both pressure sensors S3 and S4 are in the OFF state (low vacuum state) (see example (3) in FIG. 9).

[0072] In this embodiment, the two pressure sensors S3 and S4, which have different thresholds set, are used to determine the suction state of the probe card 14, but the present invention is not limited to this. For example, a pressure sensor that can set multiple thresholds may be used.

[0073] [Prober control method] (When probe card is installed) Next, a procedure for mounting the probe card 14 on the head stage 18 will be described with reference to Fig. 10. In the following description, mounting of the probe card 14 in the measurement unit SU1 (solenoid valve V6) will be described as an example, and the description of the cases of the other measurement units SU2 to SU5 will be omitted.

[0074] First, the controller 40 turns off the solenoid valve V1 on the vacuum suction line L1-1 side and turns on the solenoid valve V6 on the vacuum suction line L2-1 side to suction the probe card 14 by the sub-vacuum (VC2) (step ST10).

[0075] Next, the control device 40 acquires the sensor states of the pressure sensors S3 and S4 to determine the suction state of the probe card 14 (step ST12). In step ST12, if the suction state of the probe card 14 is not a normal suction state, that is, if the pressure sensor S3 is in an OFF state (see Figs. 7 to 9), the control device 40 notifies the operator of the abnormality in the suction state of the probe card 14 and proceeds to a retry recovery process (step ST14).

[0076] On the other hand, in step ST12, when the suction state of the probe card 14 is normal, that is, when both the pressure sensors S3 and S4 are ON (see FIG. 6 and FIG. 9), the control device 40 turns ON the solenoid valve V1 on the vacuum suction line L1-1 side to start suction of the probe card 14 by the main vacuum (VC1) (step ST16). Then, after a specified time (delay) has elapsed (step ST18), the control device 40 turns OFF the solenoid valve V6 on the vacuum suction line L2-1 side (vacuum source VC2 side is shut off and the measurement unit SU side is open) to stop suction of the probe card 14 by the sub-vacuum (VC2) (step ST20). This switches to suction by the main vacuum (vacuum source VC1).

[0077] Next, the control device 40 acquires the sensor states of the pressure sensors S3 and S4 to determine the suction state of the probe card 14 (step ST22). In step ST22, if the suction state of the probe card 14 is other than the normal suction state, that is, if the pressure sensor S3 is in the OFF state (see Figs. 7 to 9), the control device 40 notifies the operator of the abnormality in the suction state of the probe card 14 and proceeds to a retry recovery process (step ST24).

[0078] On the other hand, if the probe card 14 is properly attracted in step ST22, the mounting process of the probe card 14 ends normally.

[0079] According to this embodiment, the process from the presence check to the suction to the head stage (18-1 to 18-5) is carried out via vacuum suction lines (L2-1 to L2-5) provided with check valves (C6 to C10), thereby preventing a decrease in vacuum pressure in the vacuum suction line L1 due to empty suction during the presence check.

[0080] (When checking the status of the probe card) Next, the process of checking the state of the probe card 14 after the probe card 14 is attached to the head stage 18 will be described with reference to Fig. 11. The state of the probe card 14 shown in Fig. 11 is checked, for example, when the measuring unit SU of the prober 1 is initialized, when the probe card 14 is replaced (at the start and end of the replacement), or at the start of a wafer-level inspection (at the start of a lot). Note that in the following description, the probe card state check in the measuring unit SU1 (solenoid valve V6) will be taken as an example, and a description of the cases of the other measuring units SU2 to SU5 will be omitted.

[0081] First, the control device 40 acquires the sensor states of the pressure sensors S3 and S4 to determine the suction state of the probe card 14 (step ST30). In step ST30, if the suction state of the probe card 14 is normal, that is, if both the pressure sensors S3 and S4 are ON (see FIGS. 6 and 9), the state check of the probe card 14 is completed, and normal operation (wafer level inspection, etc.) is possible.

[0082] On the other hand, in step ST30, if the suction state of the probe card 14 is incomplete, that is, if the pressure sensor S3 is OFF and the pressure sensor S4 is ON (see FIG. 7 and FIG. 9), the control device 40 turns OFF the solenoid valve V1 on the vacuum suction line L1-1 side and turns ON the solenoid valve V6 on the vacuum suction line L2-1 side to suction the probe card 14 by the sub-vacuum (VC2) (step ST32).Then, the control device 40 acquires the sensor states of the pressure sensors S3 and S4 and judges the suction state of the probe card 14 again (step ST34).

[0083] In step ST34, if the suction state of the probe card 14 is incomplete, the control device 40 notifies the operator of the abnormality in the suction state of the probe card 14 (maintenance call), and the check of the state of the probe card is completed.

[0084] On the other hand, if the suction state of the probe card 14 is normal in step ST34, the control device 40 turns on the solenoid valve V1 on the vacuum suction line L1-1 side to start suction of the probe card 14 by the main vacuum (VC1) (step ST36).Then, the control device 40 acquires the sensor states of the pressure sensors S3 and S4 and judges the suction state of the probe card 14 again (step ST38).

[0085] In step ST38, if the suction state of the probe card 14 is other than the normal suction state, the control device 40 notifies the operator of the abnormality in the suction state of the probe card 14 (maintenance call), and the state check of the probe card 14 is completed.

[0086] On the other hand, if the suction state of the probe card 14 is normal in step ST38, the control device 40 turns off the solenoid valve V6 on the vacuum suction line L2-1 side (vacuum source VC2 side is shut off and measurement unit SU side is open) to stop suction of the probe card 14 by the sub-vacuum (VC2) (step ST40). This switches to suction by the main vacuum (vacuum source VC1). This ends the state check of the probe card 14, and the device becomes ready for normal operation (wafer level inspection, etc.).

[0087] On the other hand, in step ST30, when the suction state of the probe card 14 is a card-absent state, that is, when both pressure sensors S3 and S4 are in the OFF state (see Figures 8 and 9), the control device 40 acquires the sensor state of the pressure sensor S2 on the sub-vacuum (vacuum source VC2) side and determines the state of the vacuum source VC2 and the state of the vacuum suction lines L2 and L2-1 on the vacuum source VC2 side (step ST42).

[0088] In step ST42, if the pressure sensor S2 is in the OFF state, the control device 40 notifies the operator of an abnormality on the vacuum source VC2 side (maintenance call), and the check of the state of the probe card 14 is completed.

[0089] On the other hand, if the pressure sensor S2 is ON in step ST42, the control device 40 turns OFF the solenoid valve V1 on the vacuum suction line L1-1 side and turns ON the solenoid valve V6 on the vacuum suction line L2-1 side to suction the probe card 14 by the sub-vacuum (VC2) (step ST44).Then, the control device 40 acquires the sensor states of the pressure sensors S3 and S4 and judges the suction state of the probe card 14 again (step ST46).

[0090] In step ST46, if the suction state of the probe card 14 remains in the card-absent state, the control device 40 turns off the solenoid valve V6 on the vacuum suction line L2-1 side (vacuum source VC2 side is blocked and measurement unit SU side is open) to stop the suction of the probe card 14 by the sub-vacuum (VC2) (step ST48), and then notifies the operator of an abnormality in the suction state of the probe card 14 (maintenance call), and the probe card status check is completed.

[0091] On the other hand, if the suction state of the probe card 14 is normal in step ST46, the control device 40 turns on the solenoid valve V1 on the vacuum suction line L1-1 side to start suction of the probe card 14 by the main vacuum (VC1) (step ST36).Then, the control device 40 acquires the sensor states of the pressure sensors S3 and S4 and judges the suction state of the probe card 14 again (step ST38).

[0092] In step ST38, if the suction state of the probe card 14 is other than the normal suction state, the control device 40 notifies the operator of the abnormality in the suction state of the probe card 14 (maintenance call), and the state check of the probe card 14 is completed.

[0093] On the other hand, if the suction state of the probe card 14 is normal in step ST38, the control device 40 turns off the solenoid valve V6 on the vacuum suction line L2-1 side (vacuum source VC2 side is shut off and measurement unit SU side is open) to stop suction of the probe card 14 by the sub-vacuum (VC2) (step ST40). This switches to suction by the main vacuum (vacuum source VC1). This ends the state check of the probe card 14, and the device becomes ready for normal operation (wafer level inspection, etc.).

[0094] According to this embodiment, when it is detected that the suction state of the probe card 14 is other than the normal suction state, the sub-vacuum (vacuum source VC2) is used to prevent a drop in vacuum pressure caused by the misalignment of the probe card 14 or the like, and to transition to the normal suction state.

[0095] In this embodiment, the vacuum suction lines L2-1 to L2-5 are connected to the head stages 18-1 to 18-5 after merging with the vacuum suction lines L1-1 to L1-5, respectively, but the present invention is not limited to this. For example, the vacuum suction lines L2-1 to L2-5 and the vacuum suction lines L1-1 to L1-5 may be independent of each other (separate without merging), and the vacuum suction lines L2-1 to L2-5 may be directly connected to the head stages 18-1 to 18-5, respectively. In this case, pressure sensors for detecting the suction state of the probe card 14 may be provided on both the vacuum suction lines L1-1 to L1-5 and the vacuum suction lines L2-1 to L2-5, and the suction state during the main vacuum output and the sub-vacuum output may be determined using the pressure sensors provided on the vacuum suction lines L1-1 to L1-5 and the vacuum suction lines L2-1 to L2-5, respectively. [Explanation of symbols]

[0096] 1... prober, SU1 to SU5... measurement unit, 100... suction mechanism, VC1 to VC3... vacuum source, L1, L1A, L1B, L1-1 to L1-5, L2, L2-1 to L2-5, L3-1 to L3-5... vacuum suction line, S1 to S4... pressure sensor, R1... vacuum regulator, V1 to V10... solenoid valve, C6 to C10... check valve, 12... wafer chuck, 14-1 to 14-5... probe card, 16... probe, 18-1 to 18-5... head stage, 20... alignment device, 22... Z stage, 24... X carriage, 26... Y carriage, 28... suction port, 30... suction path, 40... control device, W... wafer,

Claims

1. a probe card having probes for testing the wafer; a probe card suction unit to which the probe card is suctioned; a first vacuum source connected to the probe card suction unit via a first vacuum suction line for suctioning and holding the probe card on the probe card suction unit; a second vacuum source connected to the probe card suction unit via a second vacuum suction line for suctioning and holding the probe card on the probe card suction unit; a backflow prevention means provided in the second vacuum suction line; a control device that switches to suction by the first vacuum source after the probe card is suctioned to the probe card suction unit by the second vacuum source; A prober comprising:

2. a pressure sensor for detecting an adsorption state of the probe card; The prober according to claim 1 , wherein the control device adsorbs the probe card to the probe card suction unit using the second vacuum source, and when the suction state becomes a normal suction state, switches to suction using the first vacuum source.

3. The prober of claim 2, wherein when switching from suction by the second vacuum source to suction by the first vacuum source, the control device starts suction by the first vacuum source while maintaining suction by the second vacuum source, then stops suction by the second vacuum source and switches to suction by only the first vacuum source.

4. the first vacuum suction line and the second vacuum suction line are connected to the probe card suction unit via a common vacuum suction line; 4. The prober according to claim 2, wherein the pressure sensor is provided on the common vacuum suction line.

5. a first solenoid valve provided in the first vacuum suction line; a second solenoid valve provided in the second vacuum suction line; The prober described in any one of claims 1 to 4, wherein the control device adsorbs the probe card to the probe card suction unit using the second vacuum source by putting the first solenoid valve into a shut-off state and the second solenoid valve into a connected state, and switches to suction using the first vacuum source by putting the second solenoid valve into a shut-off state and the first solenoid valve into a connected state.

6. A method for controlling a prober comprising: a first vacuum source connected to a probe card suction unit via a first vacuum suction line for suctioning and holding a probe card on the probe card suction unit; and a second vacuum source connected to the probe card suction unit via a second vacuum suction line provided with a backflow prevention means for suctioning and holding the probe card on the probe card suction unit, adsorbing the probe card to the probe card suction unit by the second vacuum source; a step of switching to suction by the first vacuum source after suctioning the probe card to the probe card suction unit by the second vacuum source; A method for controlling a prober comprising the steps of:

7. adsorbing the probe card to the probe card suction unit by the second vacuum source; detecting an adsorption state of the probe card based on an output from a pressure sensor after the second vacuum source has been adsorbed, and switching to adsorption by the first vacuum source when the adsorption state becomes a normal adsorption state; 7. The method for controlling a prober according to claim 6, comprising:

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