JP4911941B2 - Prober - Google Patents

Description

  The present invention relates to a prober for connecting an electrode of a die to a tester in order to perform an electrical inspection of a plurality of semiconductor chips (dies) formed on a semiconductor wafer.

  In the semiconductor manufacturing process, various processes are performed on a thin disk-shaped semiconductor wafer to form a plurality of chips (dies) each having a semiconductor device (device). Each chip is inspected for electrical characteristics, then separated by a dicer, and then fixed to a lead frame and assembled. The inspection of the electrical characteristics is performed using a prober and a tester. The prober fixes the wafer to the stage and brings the probe into contact with the electrode pad of each chip. The tester supplies power and various test signals from a terminal connected to the probe, analyzes signals output to the electrodes of the chip, and confirms whether or not it operates normally.

  FIG. 1 is a diagram showing a basic configuration of a system for inspecting chips on a wafer using a prober and a tester. As shown in the figure, the prober 10 includes a base 11, a moving base 12 provided thereon, a Y-axis moving table 13, an X-axis moving table 14, a wafer stage Z moving unit 15, and a wafer stage Z. A moving stage 16, a θ rotation unit 17, a wafer stage 18 for holding a wafer W, a processing stage Z moving unit 19, a processing stage Z moving table 20, a needle alignment camera 21 for detecting the position of the probe, A cleaning stage 22 for cleaning the probe, support columns 23 and 24, a head stage 25, a wafer alignment camera 26 provided on the support column 23, a card holder 27 provided on the head stage 22, and a card holder 27. And a probe card 28. The movement base 12, the Y-axis movement table 13, and the X-axis movement table 14 constitute a movement mechanism that moves in a two-axis (X-axis, Y-axis) direction in a horizontal plane, and includes a wafer stage Z movement unit 15, a wafer The stage Z moving table 16 and the θ rotating unit 17 constitute a moving / rotating mechanism that moves the wafer stage 18 in the vertical (Z axis) direction and rotates around the Z axis, and the processing stage Z moving unit 19 includes: A moving mechanism for moving the processing stage Z moving table 20 in the vertical (Z-axis) direction is configured. Since the moving / rotating mechanism is widely known, the description thereof is omitted here. The probe card 27 has a probe 28 arranged according to the electrode arrangement of the device to be inspected, and is exchanged according to the device to be inspected. The reason why the wafer stage Z moving table 16 and the processing stage Z moving table 20 moving in the Z-axis direction are moved by separate moving mechanisms will be described later.

  The tester 30 includes a tester body 31 and a contact ring 32 provided on the tester body 31. The probe card 25 is provided with a terminal connected to each probe, and the contact ring 32 has a spring probe 33 arranged so as to contact the terminal. The tester body 31 is held with respect to the prober 10 by a support mechanism (not shown).

  When performing inspection, the X-axis moving base 14 is moved so that the needle alignment camera 21 is positioned below the probe 29, and processing is performed so that the focal position of the needle alignment camera 19 is aligned with the tip of the probe 29. The stage Z moving table 20 is moved up and down to detect the tip position of the probe 29. The detection of the tip position of the probe 29 must be performed whenever the probe card is replaced, and is appropriately performed every time a predetermined number of chips are measured even when the probe card is not replaced.

  Next, with the wafer W to be inspected held on the wafer stage 18, the wafer stage Z moving table 16 is moved so that the wafer W is positioned below the wafer alignment camera 26, and the focal position of the wafer alignment camera 26 is adjusted. The wafer stage Z moving table 18 is moved up and down to match the electrode pads of the semiconductor chip, and the position of the electrode pads of the semiconductor chip on the wafer W is detected. It is not necessary to detect the positions of all the electrode pads of one chip, and the positions of several electrode pads may be detected. Further, it is not necessary to detect the electrode pads of all the chips on the wafer W, and the positions of the electrode pads of several chips are detected.

  Next, the θ rotation unit 17 is rotated so that the arrangement direction of the electrode pads coincides with the arrangement direction of the tips of the probes 29, and the electrode pads of the chip to be inspected are moved so as to be positioned directly below the probes 29, and then the wafer. The stage Z moving table 16 is moved upward and the electrode pad is brought into contact with the probe 29 to perform inspection.

  When the electrode pad is brought into contact with the probe 29, the electrode pad wrinkles may adhere to the probe. Therefore, the probe 29 needs to be appropriately cleaned. When the cleaning process of the probe 29 is performed, the cleaning stage 22 is moved so as to be positioned below the probe 29, and then the cleaning stage 22 is raised and brought into contact with the probe 29. The cleaning stage 22 is provided with a cleaning sheet for removing wrinkles on the electrode pad, a brush for removing wrinkles on the cleaning sheet, and the like, and a cleaning process is performed by bringing the cleaning sheet or brush into contact with the probe 29.

  FIG. 2 shows a state where the cleaning stage 22 is in contact with the probe 29. As shown in the drawing, when the cleaning stage 22 moves below the probe 29, the wafer stage 18 moves to the left side, but since the wafer alignment camera 26 exists at that portion, the collision between the wafer stage 18 and the wafer alignment camera 26 occurs. In order to avoid this, the wafer stage 18 is lowered.

  The prober is described in, for example, Patent Document 1 and is widely known, so detailed description thereof will be omitted.

  Next, the reason why the wafer stage Z moving table 16 and the processing stage Z moving table 20 moving in the Z-axis direction are independently moved by different moving mechanisms as shown in FIGS. 1 and 2 will be described. In terms of cost, it is desirable that there is one moving mechanism, and it is conceivable that the wafer stage Z moving table 16 and the processing stage Z moving table 20 are shared and moved by one moving unit. In that case, both the wafer stage 18 and the cleaning stage 22 need to move up and down to a position in contact with or close to the probe 29. As shown in the figure, the wafer alignment camera 26 needs to be arranged, the high-resolution wafer alignment camera 26 has a short working distance, and the wafer stage 18 needs to be raised to a position close to the wafer alignment camera 26. When the electrode pad on the wafer W is detected by the wafer alignment camera 26, the cleaning stage 22 is required not to contact the probe 29 unnecessarily, and when the electrode pad on the wafer W is brought into contact with the probe 29, the wafer It is required that the stage 18 does not contact the wafer alignment camera 26. In the case where the wafer stage Z moving table 16 and the processing stage Z moving table 20 are made common, in order to satisfy such a requirement, the wafer alignment camera 26 is arranged at a position that is a long distance away from the probe card 28 in the horizontal direction. Become. In this case, it is necessary to lengthen the moving distance of the Y-axis moving table 13 or the X-axis moving table 14, which increases the cost. In particular, in recent years, the diameter of wafers has increased and the diameter of wafer stage 18 has also increased. Further, since the number of electrode pads of the semiconductor chip is increased, the diameter of the probe card 28 is also increased. Therefore, if it arrange | positions so that said request | requirement may be satisfy | filled, the movement distance of the Y-axis moving stand 13 or the X-axis moving stand 14 will become very long, and the problem that cost will increase rapidly will arise. As described above, it is difficult to move the wafer stage Z moving table 16 and the processing stage Z moving table 20 in common by one moving mechanism because of many restrictions.

  On the other hand, as shown in FIGS. 1 and 2, if the wafer stage Z moving table 16 and the processing stage Z moving table 20 can be moved independently by different moving mechanisms, the respective height positions can be arbitrarily set according to the operation. The problem of collision can be easily avoided. This is the reason why the wafer stage Z moving table 16 and the processing stage Z moving table 20 can be moved independently by separate moving mechanisms.

  The needle alignment camera 19 also needs to move in the vertical direction in order to align the focal position with the probe 29, and may be provided in another Z movement mechanism due to various restrictions. However, in this case, three movement mechanisms in the Z-axis direction are required, and the cost increases. Therefore, in the example of FIGS. 1 and 2, the needle alignment camera 19 is provided on the processing stage Z moving table 20. .

JP 2004-039752 A (Overall)

  In the conventional prober, at least two Z movement mechanisms are provided for the reasons described above, but these Z movement mechanisms are highly functional in terms of movement accuracy, rigidity, movement speed, acceleration, and the like. Is a major part of the cost. Therefore, cost reduction is demanded.

  In addition, such a Z moving mechanism has a problem that it has a complicated structure and is heavy, and a reduction in weight is required.

  In addition, for the reasons described above, two Z movement mechanisms are provided to reduce the overall size. However, the Z movement mechanism has a problem of occupying a large space due to its complicated structure, and the entire size is reduced. Therefore, space saving is required.

  Further, since the two Z moving mechanisms operate independently, vibrations during operation may influence each other to cause large vibrations, and a design that does not cause such large vibrations is required.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems and to realize a low-cost, small, lightweight, low-vibration prober Z moving mechanism.

  In order to achieve the above object, the prober of the present invention includes a feeding mechanism, a wafer stage moving mechanism that moves the wafer stage in the Z-axis direction with respect to the feeding mechanism, and a processing stage that feeds the feeding mechanism. The wafer stage Z moving table and the processing stage Z moving table are moved by a moving mechanism including a processing stage moving mechanism that moves in the Z-axis direction opposite to the wafer stage.

  That is, the prober of the present invention is a prober for connecting each terminal of the tester to the electrode of the semiconductor device in order to inspect the semiconductor device formed on the wafer by the tester, and to the electrode of the semiconductor device. A probe card having a probe that contacts and connects the electrode to a terminal of the tester; a wafer stage that holds a wafer; a processing unit that performs a predetermined process on the probe; and the wafer stage and the processing unit. A first movement mechanism that moves in a first direction; and a common movement mechanism that holds the first movement mechanism and controls the first movement mechanism in a direction perpendicular to the first direction. A feed mechanism, a wafer stage moving mechanism that moves the wafer stage in the first direction with respect to the feed of the feed mechanism, and the processing means for feeding the feed mechanism. And a processing stage moving mechanism for moving in the first direction of the wafer stage and the reverse Te, characterized in that it comprises.

  The inventor of the present invention paid attention to the fact that the two stages need only be able to move in the Z-axis direction in order to avoid a collision with a portion provided around the probe. According to the present invention, the first (Z-axis) moving mechanism moves the wafer stage and the processing means (stage) in the opposite directions with respect to the feeding of the feeding mechanism, so that the object probe provided on one stage is moved to the probe. When the contact operation is performed, it can be easily designed to avoid the other stage from colliding with a portion provided around the probe. In addition, since the feeding mechanism is common, the cost can be reduced, space saving and weight reduction can be achieved, and vibration can be reduced.

  The processing means includes, for example, a cleaning mechanism for cleaning the probe and a needle position detection mechanism for detecting the arrangement of the probe.

  The first (Z-axis) moving mechanism can be realized by configuring the feed mechanism to include a ball screw and a motor that rotates the ball screw, and the wafer stage moving mechanism and the processing stage moving mechanism each include a taper cam mechanism.

  According to the present invention, a low-cost, small and light prober can be realized, and the vibration of the moving mechanism is reduced, so that the moving accuracy is improved.

  Examples of the present invention will be described below. The embodiment of the present invention has the same configuration as the conventional prober described with reference to FIGS. 1 and 2, and only the portion placed on the X-axis moving table 14 is different, so only this portion will be described. .

  FIG. 3 shows a Z-axis (first) moving mechanism placed on the X-axis moving table 14 in the prober of the embodiment, and the wafer stage 18, the needle alignment camera 21, and the cleaning stage 22 moved thereby. It is a figure which shows the structure of this part.

  As shown in FIG. 3, this portion includes a base 51, a motor 52, a ball screw 53 rotated by the motor 52, and first and second support members 54 and 55 that support a rotation shaft including the ball screw 53, The first and second moving parts 56 and 57 having nuts engaged with the taper cam mechanism and the ball screw 53, and the first supporting member 54 are supported so as to be movable in the Z-axis direction. Accordingly, the first Z moving portion 58 that moves in the Z axis direction by the taper cam mechanism and the second supporting member 55 are supported so as to be movable in the Z axis direction, and the taper cam mechanism moves Z by the movement of the second moving portion 57. It is comprised with the 2nd Z moving part 59 which moves to an axial direction. The wafer stage 18 is supported on the first Z moving unit 58, and the needle alignment camera 21 and the cleaning stage 22 are supported on the second Z moving unit 59.

  When the ball screw 53 rotates in the forward direction, the first and second moving parts 56 and 57 having nuts engaged with the ball screw 53 move in the right direction. When the first moving unit 56 moves rightward, the first Z moving unit 58 moves downward by the taper cam mechanism. When the second moving part 57 moves to the right, the second Z moving part 59 moves upward by the taper cam mechanism. Similarly, when the ball screw 53 rotates in the reverse direction, the first and second moving portions 56 and 57 move in the left direction. When the first moving unit 56 moves leftward, the first Z moving unit 58 moves upward by the taper cam mechanism. When the second moving part 57 moves leftward, the second Z moving part 59 moves downward by the taper cam mechanism. As described above, the first Z moving unit 58 and the second Z moving unit 59 move in the vertical direction according to the rotation of the ball screw 53, but the moving directions are opposite.

  The operation of the prober having the configuration shown in FIG. 3 placed on the X-axis moving table 14 in FIG. 1 will be described. When the wafer W held on the wafer stage 18 is brought into contact with the probe 29, the second Z moving unit 59 is set lower than the first Z moving unit 58, in other words, the cleaning stage 22 is set lower than the wafer stage 18. Then, after moving so that the electrode pad of the chip of the wafer W is positioned immediately below the probe 29, the wafer stage 18 is moved upward to bring the electrode pad into contact with the probe 29. At this time, the cleaning stage 22 moves further downward.

  When the cleaning stage 22 is brought into contact with the probe 29, the cleaning is performed after the wafer stage 18 is sufficiently lower than the cleaning stage 22 so that the first Z moving unit 58 is sufficiently lower than the second Z moving unit 59. The stage 22 moves so as to be positioned under the probe 29. At this time, since the wafer stage 18 is at a low position, it does not collide with the wafer alignment camera 26. Then, the cleaning stage 22 is moved upward and brought into contact with the probe 29. At this time, the wafer stage 18 moves further downward.

  When the position of the probe 29 is detected by the needle alignment camera 21, it is the same as when the cleaning stage 22 is brought into contact with the probe 29 except that the needle alignment camera 21 is positioned below the probe 29.

  When the position of the electrode pad of the chip on the wafer W is detected by the wafer alignment camera 26, it is similar when the cleaning stage 22 is brought into contact with the probe 29, and the electrode pad of the target chip is positioned below the wafer alignment camera 26. After that, the wafer stage 18 is moved upward to adjust the focal position of the wafer alignment camera 26 on the electrode pad. At this time, the cleaning stage 22 moves downward.

  The present invention can be applied to any prober as long as it is a prober having a needle alignment camera for detecting the probe position or a probe cleaning mechanism. Particularly, a large-diameter wafer is to be inspected and has a large diameter. It is effective when applied to a prober using a probe card.

It is a figure which shows the basic composition of the wafer test system which test | inspects the chip | tip on a wafer with a prober and a tester. It is a figure which shows the different movement state in the wafer test system of FIG. It is a figure which shows the structure of the Z moving mechanism of an Example.

Explanation of symbols

18 Wafer Stage 21 Needle Positioning Camera 22 Cleaning Stage 26 Wafer Alignment Camera 28 Probe Card 29 Probe 52 Motor 53 Ball Screw 56 First Moving Unit 57 Second Moving Unit 58 First Z Moving Unit 59 Second Z Moving Unit

Claims (4)

A prober for connecting each terminal of the tester to an electrode of the semiconductor device in order to inspect the semiconductor device formed on the wafer with a tester,
A probe card having a probe that contacts the electrode of the semiconductor device and connects the electrode to a terminal of the tester;
A wafer stage for holding the wafer;
Processing means for performing predetermined processing on the probe;
A first moving mechanism for moving the wafer stage and the processing means in the Z-axis direction;
A common movement mechanism that holds the first movement mechanism and controls the first movement mechanism in a direction perpendicular to the Z-axis direction;
The first moving mechanism includes:
A feed mechanism;
A wafer stage moving mechanism for moving the wafer stage in the Z-axis direction with respect to the feed of the feed mechanism;
A prober, comprising: a processing stage moving mechanism that moves the processing means in the Z-axis direction opposite to the wafer stage with respect to the feeding of the feeding mechanism.   The prober according to claim 1, wherein the processing unit includes a cleaning mechanism for cleaning the probe.   The prober according to claim 1, wherein the processing unit includes a needle position detection mechanism that detects an arrangement of the probe. The feed mechanism includes a ball screw and a motor that rotates the ball screw,
The prober according to claim 1, wherein each of the wafer stage moving mechanism and the processing stage moving mechanism includes a taper cam mechanism.

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