JPH09321099A - Wafer prober - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust the parallelism of a wafer stage during measurement of a wafer more simply and stably by providing a wafer adjuster with a levelness adjusting means which adjusts the horizontal angle of a head stage and besides a holding means which holds the horizontal position after adjustment. SOLUTION: This wafer prober is provided with a levelness adjusting means which adjusts the horizontal angle of a head stage 6 so that the probe needles 8 contact with the electrodes of a die, severally, in a state of the head stage 6 having a probe card 5 mounted, and a holding means which holds the horizontal position after adjustment. For example, the levelness adjusting means has such structure as to adjust the position so that the head stage 6 may be horizontal by rotating and moving vertically a plurality of adjusting screws 3 which are screwed in screw holes and pierce springs 9 and whose tips contact always with the inner surfaces of bearing recesses. Moreover, the holding means are made a plurality of lock screws 10 being so provided as to pierce a prober top board 7, each in proximity to a plurality of screws 3 for upper and lower adjustment, and contact with the head stage 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer prober, and more particularly to a wafer prober having a horizontal adjustment mechanism for a wafer stage on an upper surface of the prober.

[0002]

2. Description of the Related Art Referring to FIG. 2 showing a schematic structure of a main part of a conventional wafer prober of this kind, it is connected to a head stage 6 which is disposed in contact with an upper surface part 7 of a prober and serves as a setting part of a probe card. The ring 11 is attached. The probe card 5 is attached to the lower surface of the connection ring 11, and the test head 12 is connected to the upper surface of the connection ring 11, so that the probe card 5 is connected to the test head 12 via the connection ring 11. A probe probe 8 is provided on the lower surface of the probe card 5, and the wafer stage 1 located below the probe card 5 is provided.
When the wafer stage 1 rises, the electrode on the surface of the wafer 2 and the probe probe 8 on the lower surface of the probe card 5 come into contact with the upper wafer 2, and the wafer 2 connects the probe probe 8, the probe card 5 and the connection ring. Test head 12 through
Electrically connected to.

[0003] A large number of semiconductor integrated circuit dies are formed on the surface of a wafer 2, and one die usually has several tens to
Since hundreds of signal input / output electrodes are formed, probe probes 8 are also provided on the probe card 5 corresponding to these electrode arrangements. When the stage 1 is raised, these electrodes and the probe probe 8 come into contact at the same time, and the test signal supplied from the test head 12 causes the circuit formed on the semiconductor integrated circuit die to operate. It is taken out to the test head 12 by the probe 8 and an electrical characteristic test is performed.

In the above-described wafer measurement by the wafer prober, since the semiconductor integrated circuit dies are sequentially measured one by one, the horizontality of the head stage 6 can be absorbed by the stylus pressure of the probe 8. Was.

However, in recent years, parallelization of wafer measurement by a wafer prober has been progressing, and it has become difficult to absorb the horizontality of the head stage 6 only by the stylus pressure of the probe probe 8.

[0006] The parallel measurement here is to measure a plurality of semiconductor integrated circuit dies at the same time. As the arrangement area of the probe probes 8 increases as the parallel measurement progresses, the above-described head stage 6 can be measured. The height deviation due to the inclination of the horizontality is from several μm when measuring one conventional semiconductor integrated circuit die to several tens μm when measuring in parallel, and it is no longer in a state where it can be absorbed by the stylus pressure of the probe 8. Have been.

One example of a method of correcting a height deviation due to the inclination of the horizontality of the head stage 6 is disclosed in Japanese Patent Laid-Open No. 5-1448.
No. 92 publication.

Referring to FIG. 3 which shows a configuration diagram of a main part of the wafer prober described in the publication, FIG. 3 shows a case where the horizontal angle is adjusted by using three or more arms 13, and Arm 13 which is moved vertically by a cylinder or a motor under the stage 1 on which the
Are mounted on the support base 15 at equal intervals. When the probe card 5 is not horizontal, three or more arms 13
By moving the stage up and down, the angle can be freely adjusted so as to be parallel to the probe card 5. At this time, a stage support 14 is provided between the center of the stage 1 and the support 15. Therefore, the center position of the angle adjustment by the stage support 14 is constant.

[0009]

As described above, in the conventional wafer prober, if the arrangement area of the probe probes 8 is small, the entire probe probes 8 are obliquely mounted. Using the elasticity generated in relation to the pressure, the inclination of the horizontality could be absorbed.

However, since parallel measurement has been generally performed, as the array area of the probe probes 8 is enlarged, the height deviation due to the inclination of the horizontality of the head stage 6 is reduced by the conventional semiconductor. From several μm when measuring one integrated circuit die to several tens μm when measuring in parallel, it has become impossible to absorb the inclination of the horizontality by utilizing the elasticity of the probe 8.

Therefore, as a method of correcting the height deviation, the mounting of the probe card 5 is repeatedly performed, and the arm 13 supporting the stage 1 on which the wafer 2 is mounted as described with reference to FIG. I was doing.

However, in the case of the former method, it is necessary to reattach the probe card 5 in order to adjust the horizontality, and the test head 12 and the head stage 6 are opened and closed each time. Man-hours were required.

In the latter case, a driving system such as a motor mounted on the wafer stage 1 which moves at high speed and in a wide range needs to further include a driving system for adjusting the horizontality separately from its own driving system. It is inevitable that the cost will increase from the top and also in securing the stability of accuracy.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a mechanism for correcting the parallelism of a wafer stage more simply and stably in wafer measurement using a wafer prober. .

[0015]

The wafer prober of the present invention is characterized in that a probe probe provided on a probe card is used to test the electrical characteristics of a semiconductor integrated circuit die formed on a semiconductor wafer. In a wafer prober that automatically contacts the electrodes of the die and serves as a signal input / output unit with a tester, the probe probe is mounted in a state in which the head stage serving as a mounting portion of the probe card is mounted with the probe card. A horizontal adjusting means for adjusting the horizontal angle of the head stage so as to contact the electrodes of the die and a holding means for holding the adjusted horizontal position are provided together.

The horizontal adjusting means has a circular opening for replacing the probe card at the center of the upper plate of the prober on which the head stage is placed, and is a circular plate fitted in the circular opening at the center. The first disk having a donut shape having an opening for placing a probe card in the portion, and the upper surface of the opening peripheral portion of the second disk having an opening larger than the opening of the disk is the first disk. Is disposed so as to overlap and contact the lower surface of the peripheral portion of the opening of the disk, and at least three locations on the upper surface of the second disk are provided with spherical recesses for bearings, which correspond to the openings of these recesses. Screw holes are provided in the prober top plate at the respective positions, and the head stage composed of the first and second disks is provided between the center of these screw holes and the center of the opening of the recess. The spring suspended from it Each of them is provided with a vertical adjustment screw that is screwed into each of the plurality of screw holes, penetrates the spring, and has a tip always in contact with the inner surface of the bearing recess. By moving the head stage up and down, the angle can be adjusted so that the head stage becomes horizontal.

Further, the spring can serve both as the suspension and the screw engagement.

Further, the holding means is provided with a plurality of lock screws which are close to the plurality of vertical adjustment screws and which penetrate the prober upper surface plate and contact the head stage. When the adjustment is started, these lock screws are provided. Each of them is rotated backward and pulled up, and after adjusting the horizontal angle of the head stage with respect to the prober upper surface plate by the plurality of vertical adjustment screws, the plurality of lock screws are respectively rotated to adjust the head stage. By lowering the head stage until it comes into contact with the surface, the head stage can be fixed so as not to move vertically at the start of measurement.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The wafer prober of the present invention has an adjusting screw mechanism for adjusting the horizontal angle of the head stage having the probe card attached to the head plate having the probe card attached. By adjusting by adjusting, the levelness of the wafer and the probe card can be easily adjusted without using a special drive system.

First, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1A is a perspective view of a main part showing an embodiment of a wafer prober of the present invention, and FIG. 1B is a cross-sectional view when a wafer stage and a head stage are in a horizontal state with each other. FIG. 1C is a cross-sectional view when the wafer stage and the head stage are inclined with respect to each other. Referring to FIG. 1A, the head stage 6 serving as a setting unit of the probe card 5 includes a horizontal adjustment unit that adjusts the horizontality when the probe card 5 is mounted and a holding unit that holds the adjusted position. Also have.

The horizontal adjusting means is provided with a circular opening for exchanging a probe card in the center of the prober upper plate 7, a donut-shaped disk fitted in the circular opening, and placing the probe card 5 in the center. A disk 6a having an opening formed therein and a disk 6b having an opening larger than the opening of the disk 6a are provided in contact with the lower surface of the opening peripheral portion of the disk 6a. At least three locations on the upper surface of the disk 6a are provided with bearing recesses 4 having a spherical inside. Screw holes are provided on the prober upper surface plate 7 at positions corresponding to the openings of these recesses 4, and the center of the screw holes is provided. Springs 9 for suspending the head stage 6 composed of the disks 6a and 6b from the prober upper surface plate 7 are respectively disposed between the center of the opening of the concave portion 4 and the prober upper surface plate 7. And the tip is always in the bearing recess 4 It has an adjusting screw 3 which is in contact with,
The position of the head stage 6 is adjusted so that the head stage 6 is horizontal by rotating the adjusting screw 3 up and down.

The holding means is provided with a plurality of lock screws which respectively penetrate the prober upper plate 7 and come into contact with the head stage 6 in close proximity to the plurality of up / down adjustment screws 3, respectively. Then, the horizontal angle of the head stage 6 with respect to the prober upper surface plate 7 is adjusted by the plurality of vertical adjustment screws 3. After this adjustment, a plurality of lock screws 10 are rotated to lower the head stage 6 until it comes into contact with the adjusted surface of the head stage 6, thereby fixing the head stage so as not to move up and down at the start of measurement.

Referring also to FIG. 1B, the wafer 2 on the wafer stage 1 located below the probe card 5
Means that the wafer 2 is raised by raising the wafer stage 1.
The electrode on the surface of the semiconductor integrated circuit die formed on the substrate contacts the probe probe 8 on the lower surface of the probe card 5, and the wafer 2 is electrically connected to the probe card 5 via the probe probe 8.

The wafer prober having the above structure is
The angle can be adjusted freely so that the wafer 2 on the wafer stage 1 and the probe card 5 are horizontal to each other by appropriately adjusting the vertical adjustment screw 3.

At this time, the backlash of the vertical adjustment screw 7 is prevented by the repulsive force of the spring 9, and at the same time, the prober upper plate 7 suspends the head stage 6.
The distance between the prober upper surface plate 7 and the head stage 6 is finely adjusted by rotating the vertical adjustment screw 3.

Referring to FIG. 1 (c), since the vertical adjustment screw 3 moves vertically with respect to the prober upper plate 7, when the left screw 3 is rotated so as to be longer downward, Since the distance between the prober upper surface plate 7 and the head stage 6 on the left side is widened and the screw on the right side remains the same, the head stage 6 has a certain inclination angle with respect to the prober upper surface plate 7, and the vertical screw 3 and the head Stage 6
The upper concave portion 4 means that if the concave portion 4 is simply a concave portion perpendicular to the upper surface of the head stage 6, the screw 3 is changed according to the inclination angle.
As the friction between the groove and the recess 4 increases, the angle cannot be adjusted smoothly.

However, in the present embodiment, the recess 4
Since the inside is a spherical bearing, even if the inclination angle of the head stage 6 is increased by the vertical movement of the screw 3, the friction between the screw 3 and the concave portion 4 is absorbed by the spherical inner surface, The angle can be adjusted smoothly.

Further, in this embodiment, a lock screw 10 which penetrates the prober upper plate 7 and reaches the head stage 6 is provided in the vicinity of the vertical adjustment screw 3, which hinders the adjustment of the vertical adjustment screw 3 at the start of the adjustment. Rotate the lock screw 10 in the reverse direction so that there is no
After adjusting the horizontal angle of the head stage 6 with respect to the prober upper plate 7 by the vertical adjustment screw 3, the lock screw 1
By rotating 0 to lower the head stage 6 until it comes into contact with the adjusted surface of the head stage 6, the head stage 6 is fixed so as not to move up and down due to vibrations at the start of measurement and the like.

[0029]

As described above, in the wafer prober of the present invention, the head stage serving as the setting section of the probe card adjusts the horizontality when the probe card is mounted, and the position after the adjustment is adjusted. The horizontal adjustment means has a circular port for exchanging a probe card at the center of the prober top plate, and a circular plate fitted into the circular port and a probe card at the center. Donut-shaped first disk having an opening in which the first disk can be placed, and the upper surface of the second disk having an opening larger than the opening of the first disk is formed as an opening of the first disk. Spherical bearing recesses are provided in at least three places on the upper surface of the second disk, and screws are provided on the upper surface plate of the prober at positions corresponding to the openings of the recesses. Holes are provided, these Springs for suspending the head stage composed of the first and second disks from the upper surface plate of the prober are respectively disposed between the center of the hole and the center of the opening of the concave portion. And vertical adjustment screws that are always in contact with the inner surface of the bearing recess, and adjust the position of the head stage so that the head stage is horizontal by rotating these adjustment screws vertically. A lock screw that penetrates the prober top plate and reaches the head stage is provided close to the vertical adjustment screw, and at the start of adjustment, the lock screw is reversely rotated and pulled up so as not to hinder the adjustment of the vertical adjustment screw,
After adjusting the horizontal angle of the head stage with respect to the prober top plate with the vertical adjustment screw, rotate the lock screw and lower it until it comes in contact with the adjusted surface of the head stage. Since the structure is provided so as not to be fixed, the horizontal angle between the wafer and the probe card can be easily adjusted, and a special drive system is not required when the horizontal angle is adjusted on the wafer stage. Therefore, it is possible to contribute to a reduction in man-hours during wafer measurement.

[Brief description of drawings]

FIG. 1A is a perspective view showing a main part of an embodiment of the present invention. (B) It is sectional drawing when a wafer stage and a head stage are mutually in a horizontal state. FIG. 4C is a cross-sectional view when the wafer stage and the head stage are inclined with respect to each other.

FIG. 2 is a perspective view showing a main part of a conventional wafer prober.

FIG. 3 is a stage diagram of another conventional wafer prober.

[Explanation of reference symbols] 1 wafer stage 2 wafer 3 screw for vertical adjustment 4 concave part for spherical bearing 5 probe card 6 head stage 7 prober top plate 8 probe probe 9 spring 10 lock screw 11 connection ring 12 test head 13 arm 14 Stage support 15 Support

Claims (4)

[Claims] 1. In order to test the electrical characteristics of a semiconductor integrated circuit die formed on a semiconductor wafer, a probe probe provided on a probe card is automatically brought into contact with an electrode of the die to provide a tester. In the wafer prober serving as a signal input / output unit of the probe card, the head stage serving as a mounting unit of the probe card is mounted on the probe card so that the probe tips come into contact with the electrodes of the die, respectively. 2. A wafer prober having a horizontal adjusting means for adjusting the horizontal angle of the above and a holding means for holding the adjusted horizontal position. 2. The horizontal adjusting means has a circular opening for replacing a probe card at the center of a prober upper surface plate on which the head stage is placed, and is a disk fitted in the circular opening at the center. The first disk having a donut shape having an opening for placing a probe card in the portion, and the upper surface of the opening peripheral portion of the second disk having an opening larger than the opening of the disk is the first disk. Is disposed so as to overlap and contact the lower surface of the peripheral portion of the opening of the disk, and at least three locations on the upper surface of the second disk are provided with spherical recesses for bearings, which correspond to the openings of these recesses. Screw holes are provided in the prober top plate at the respective positions, and the head stage composed of the first and second disks is provided between the center of these screw holes and the center of the opening of the recess. The springs suspended from And a vertical adjustment screw that is screwed into each of the plurality of screw holes, penetrates the spring, and has a tip always in contact with the inner surface of the bearing recess. The wafer prober according to claim 1, wherein the angle is adjusted so that the head stage becomes horizontal by performing the operation. 3. The wafer prober according to claim 2, wherein the spring serves both as the suspension and the screw engagement. 4. The holding means is provided with a plurality of lock screws that penetrate the prober upper surface plate and come into contact with the head stage in proximity to the plurality of vertical adjustment screws, respectively. The surface of the head stage that is adjusted by rotating the lock screws after rotating the head stage by adjusting the horizontal angle of the head stage with respect to the prober top plate with the plurality of up-down adjusting screws The head stage is fixed so as not to move up and down at the start of measurement by lowering the head stage until the head stage touches.
Wafer prober described.