JPS60213040A - Wafer prober - Google Patents

Abstract

PURPOSE:To obtain a wafer prober, which can accurately conduct teaching work automatically, by providing a control section recognizing and arithmetically operating the dimensional dispersion and mean position of a probe group. CONSTITUTION:The images of a probe group 12 intruding from an image receiving port 15a are transmitted into an optical image pickup section 18 through a fiberscope 17. A television signal generating section 21 transmits an image sensor in the optical image pickup section 18 over a recognition processing section 22. Ranges A, B, C, D shown in circles represent visual fields for the object image receiving port 15a when an XYZTHETA table 2 is moved in a probe card 13 on a prober device base 7. An arithmetic control section 6 is interfaced to the pattern recognition processing section 22, integrates the positional data of these visual fields, and arithmetically operates the data to determine the XYZ mean position and revolution of the probe group 12, thus completing teaching work. An XYZTHETA table control unit 5 receives the command of the arithmetic control section 6, controls a motor amplifying section 3 in response to detecting outputs from a position detecting section 4 and controls the speed and positioning of the table 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a wafer glover device used in a glove inspection process in a semiconductor wafer processing process.

[Background of the invention]

Generally, in the probe testing process, an automatic wafer prober device is used which sequentially performs probing of chips formed on a wafer in conjunction with a semiconductor IC tester.

FIG. 1 shows an example of the configuration of a conventionally used wafer prober device of this type. In the figure, a wafer IU, X, Y, and Z to be inspected with a glove is vacuum-fixed to an XYzθ table 2 that moves in the rotational direction. Driven in linear and rotational directions by two XYzθ tables, motor, screw feed, etc. The motor amplifier section 3
Power is applied to θ, and the position detection unit 4 receives table position information from the XYZ and rotational position detection sensors attached to the XYzθ table 2. Five XYZθ table control units receive commands from the arithmetic control unit 60 and control the motor amplifier unit 3 according to the detection output of the position detection unit 4 (7 perform speed control and positioning control of the table 2).

A wafer position detector 8 for detecting the rough position of the wafer 1 is attached to the prober device base 7, and is electrically connected to a wafer/position detection interface section 9 for calculating and detecting the outer circumference and orientation flat position of the wafer 1. .

In addition, a wafer Sg identification device @io is installed on the base 7 to recognize the chip pattern on the wafer 1.
It is connected to the recognition control section 11. The wafer recognition control section 11 interfaces with the arithmetic control section 6 to perform arithmetic recognition of the chip pattern on the wafer 1, and performs highly accurate position detection.

Next, the blobbing operation in the above-mentioned glover device will be explained regarding the normal operation when the teach-in operation described later has been completed and the position of the probe needle group 12 has already been stored in the arithmetic control section 6.

The wafers IViXYZθ are automatically supplied to the table 2 with a variation of about ±2 mm and with an undefined rotational direction. Therefore, the position fIt of the wafer 1 from the prober reference point is unknown. Therefore, position detection is performed using the following procedure.

In other words, XYzθ table 2 for the prober reference point
Since the 0 position ore position is known from the lateral position detector 4 force information, the arithmetic controller 6 issues a command to the table control unit 5 to send the table 2 to a specific position below the wafer position detector 8. Next, the table 2t is rotated at that position, and the wafer 1 is rotated under the wafer position detector 8. In this case, the detector 8 has a sufficient detection range even if the outside of the wafer 1 shakes.

During rotation, the wafer position detection interface section 9 is passed through the arithmetic control section 6 to detect the center position of the wafer 1 and the position of the orientation flat. Next, the following operation is performed to perform positioning with even higher precision using the thus obtained positional reference.

In other words, since the center position and rotation direction of the wafer 1 are known with the accuracy of the wafer position detector 80,
Next, the XYzθ table 2 can be moved to place the partial sound of a specific chip pattern on the wafer into the detection area below the wafer U identification device. The arithmetic control unit 6 calculates and recognizes the position of the chip with high precision based on the chip pattern that is transmitted from the wafer recognition control unit 11. Two or more such chip patterns are selected in advance at separate positions on the wafer, and the wafer position is finally detected with a predetermined accuracy in the arithmetic control section 6 from the positional information of the two or more positions.

Through the above operations, the position of the wafer 1 is known with high accuracy with respect to the prober reference point. Since the position of the probe needle group 12 is known in the arithmetic control unit 6, a command is issued to the XYzθ table control unit 5 to accurately position and contact the probe needle group 121 with the bonding pad in the chip on the wafer 1. I can do it. Also, Wa'-1
Since the information on the pitch in the X direction and the pitch in the Y direction between the chips on the wafer 1 is stored in advance, a large number of chips on the wafer 1 can be sequentially probed.

However, when the probe card 13 is replaced or the wire is removed and adjusted, the position of the probe needle group generally moves, and the position information of the probe needle group 12 stored in the arithmetic control unit 6 becomes invalid. In this case, it is necessary to detect the position of the probe needle group 12 on the glove card 13 newly attached to the glover device pace 7. Therefore, next, detection of this position and teaching-in of the position information to the arithmetic and control section 6 are absolutely necessary. Next, this work will be explained.

First, a rolling wafer is automatically fed to the XYzθ table 2. Next, this wafer 71 is subjected to the wafer position detection work described above, so that the wafer position relative to the prober reference position is known. Here, by manual operation, XYZ
The θ stick 14 is operated to move the XYzθ table 2 so that the bonding pads of specific chips on all of the wafers 1 are aligned and brought into contact with the probe needle group 12. Fifteen microscopes are used for this alignment work, and the relative positions of the punch ink pad and probe needle are determined visually and sensitively to ensure alignment between the two. During this time, the calculation control unit 6Fi
XYZθ table 2 or follow-up to XYZθ table 14
A command is issued to the XYZθ table control unit 5 to
Teach-in is made to the arithmetic control section 6 through the θ table control unit 5.

In this way, by aligning the glove needle with the wave vine whose position is known and storing the position information of XYZ & table 2 at that time, the position of the newly attached probe needle group is known with respect to the prober reference position. is stored in the p calculation control section 6. Note that these operations are performed by the K* line of the control program 6a stored in advance in the arithmetic control section 6.

As explained above, in the conventional wave prober device 2, it is necessary to detect the position of the probe needle group and to teach the position information to the arithmetic control section every time the glove card is completely removed.

This work was done visually under a microscope. It takes a lot of time as well as a lot of time. Furthermore, the positional information taught in due to the sensitive work lacks accuracy, making it difficult to reduce blobbing errors.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to provide a wafer that can accurately and automatically perform position detection of a group of probe needles and teach-in of the position information to a calculation control unit. - Dedicated to providing a group of probe needles.

[Summary of the invention]

In order to achieve such an object, the present invention includes an XYz scan mechanism that makes relative scanning movements between the objective image receptor and the probe needle group in the XYZ directions, and an optical processing unit that optically processes the optical images from each image receptor and converts them into electrical signals. An optical imaging section for converting the electrical signal and a pattern recognition processing section for image processing the electrical signal to recognize a globe needle image, that is, the needle size and position, are provided, and from the recognition result information, the arithmetic control section calculates the size deviation of the probe needle group. This system recognizes and calculates the position and average position. Hereinafter, the present invention will be explained in detail using Examples.

[Embodiments of the invention]

FIG. 2 is a configuration diagram showing an embodiment of the present invention.

In this embodiment, the objective image receiving aperture 15a is
It is characterized in that it is supported by a support 16 attached to the XYZ movable part of the XYZ movable part to perform an XYZ scanning movement. XYZθ
The table 2 is set to 0XYZ by the motor amplifier section 3 as before.
It is driven in the ↓ and rotational directions. That is, it has the function of moving the XYZθ table 2Vi, the entire wafer 1 in the XYZ and rotational directions, and also moves the objective image receiving aperture 15a in the XYZ directions.

On the other hand, the image of the probe needle group 12 entering from the image receiving aperture 15a is sent by the fiber scope 17, the magnification of this image is adjusted in the optical imaging section 18, and optical-to-electrical conversion is performed by the built-in imaging element. The light source 19 transmits illumination light through a fiber guide 20, and illuminates the objective image receiving aperture 15a through the entire fiber scope 17 and the half mirror in the optical imaging section 18, thereby improving the contrast of the optical image. Adjust.

The television signal generating section 21f'i drives the image sensor in the optical imaging section 18, generates a video signal, and transmits it to the pattern recognition processing section 22. Pattern recognition processing section 2
2 digitizes the video signal and stores it in memory;
The position and dispersion of the probe needle group 12 are recognized by a method of processing the stored image information in real time, or by a method of software processing using a built-in arithmetic circuit.

The arithmetic control section 6 interfaces with the pattern recognition processing section 22, provides information necessary for recognition, receives recognition result information, and finally determines the position and dispersion of the brobbing 12 based on the nVC.

According to this embodiment, the normal blobbing work can be performed as before, and the position detection work of the probe needle group 12 when the glove card 13 is replaced, that is, the teach-in work can be automatically performed. Next, this work will be explained.

The probe card 13 newly attached to the glover device base ff does not have enough i1 precision to perform groping work, but it is within f1 mm in the XY directions. Therefore, when the XYZθ table is moved to a predetermined position, the objective image receiving aperture 15a can capture an image of the probe needle group 12. The range indicated by circle A in FIG. 3 is the field of view of the objective image receiving aperture 15a at this time.

If position detection ￥t1 degree'fc3μm, globe needle 1
Try to keep about three 2a lines in your field of vision.

Next, the pattern recognition processing unit 22 is controlled while scanning in the XYzθ table 2tZ direction, and the object receiver 181015
Automatically adjust the focus of a. If the arithmetic control unit 6 reads the position information of the position detection sensor in two directions from the position detection unit 4 at this time, the height of the probe needle group in the field of view A,
In other words, two positions are known. Furthermore, the pattern recognition processing unit 22 performs other hardware and software processing on the image of the field of view A to recognize and detect the tip position and tip pitch of the glove needle 12a. By storing this information in the arithmetic control unit 6, the probe needle 12 in the field of view A
The position of a and the dispersion of the tip are known.

Next, the XYZθ table 2 is driven and the objective image receiving aperture 15a is
Scan the entire B field of view. The same pattern recognition process as described above is performed in the B field of view, and the position and tip variation of the probe needle in the B field of view are known. moreover,
For example, the C and D visual fields, or even more visual fields, are recognized in the same way, and the position and tip dispersion of the glove needle therein are known.

The arithmetic control unit 1 integrates and calculates the position data of these fields of view to determine the XYZ average position and rotation of the probe needle group 12, and the teach-in operation is also completed at the same time as the position detection operation is completed.

In addition, taking into consideration the position detection accuracy of the glove needle, the resolution of the I-type element in the optical imaging section 18, and the size of the glove card 13, the image receiving roller 15aTh is scanned as appropriate to obtain the required position detection accuracy of the probe needle group 12. .

The above work is automatically performed as execution of the position detection work control program section 6b added to the control program 6a of the arithmetic control section 60. Next, FIG. 4 is a block diagram showing another embodiment of the present invention. Deroru. This embodiment includes two image receptors, a first objective image receptor 24 and a second objective image receptor 25, each of which has a first optical system XY.
The hollow probe needle group 1 is held by the support 28° 29 in the Z scan mechanism section 26 and the second optical system XYZ scan mechanism section 2T.
It is characterized by having a structure that scans 2.

The first control unit 30 and the second control unit 31 are
It is possible to control the positioning work of the first optical system XYZ scan mechanism section 26 and the second optical system xYZ scan mechanism section 2T, respectively, and to hold and detect the current position as information.

Each of these control units 30 and 31 is also controlled by the arithmetic control section 60 commands.

Optical images entering from the first objective image receiving aperture 24 and the second objective image receiving aperture 25 are optically transferred by the first fiber scope 32 and the second fiber scope 33, and are transferred to the first optical imaging section 34 and the second optical imaging section, respectively. 35, the magnification of the image is gte
The soil is converted into an electrical signal by a built-in image sensor. Further, the first light source 36 and the second light source 37 provide illumination to obtain an optical image, as in the example of FIG. 2, and further adjust the contrast of the image. The first television signal generation section 38 and the second television signal generation section 39 also fully drive the image pickup devices as in the example shown in FIG. 2, generate video signals, and transmit the pattern to the processing section 40. The pattern recognition processing section 40 processes the finger output 17 and the two-channel video signal transmitted to the first television signal generation section 3B and the second television signal generation section 3902 channels.

In this embodiment, the XYzθ table 2f'f and the motor
1 section 3, position detection section 4, and X
Arithmetic control section 6 via YZθ table control unit 51
connected to. The wafer position detector is also connected to the arithmetic control unit 6 via the wafer position detection interface unit 9, but is separated from the probe stopper 12 like the 2N wafer position detection interface unit 9 and the wafer recognition control unit 11. Instead of using a method that recognizes the chip pattern with high precision at a fixed position, we decided to use a method that captures the chip pattern image directly under probe button #12 and performs high precision recognition and positioning using pattern recognition processing 11i4LI. I? be a sign. Next, the blobbing operation in this embodiment will be explained.

Even in this embodiment, when the glove card 13 is completely replaced or removed and adjusted, it is better to detect the position of the probe needle group in advance before the normal blowing work, which will shorten the total time for the blowing work. This teach-in operation will be explained first, since it is advantageous for this purpose.

Probe card 1 set on blower device base 7
Since the mounting accuracy for the base 7 of 3 is within the range of a low fit, the first element system XYZ scan mechanism section 2
6, when the first objective image receiving aperture 24 is moved to a predetermined specific position, for example, an image of field of view A in FIG. 3 can be obtained at the first objective image receiving aperture 24. Further similar work↓
An image of the field of view C can be obtained on the second objective image receptor 25.

Next, in the same way as the example in FIG.
By performing a scanning operation from C to field of view B, and also by automatically focusing the tip of the probe needle at the second objective image receptor 25 and scanning from field of view C2) to field of view B, variations in the position and dimensions of the glove needle can be eliminated. is determined in the arithmetic control section 6. As a result, the position and dimensional variations of the probe needle group 12 are known, and the teach-in operation is completed.

Next, the groping work will be explained. The input wedge 1 is fixed on the XYZθ table 2, and the wedge position detector 8 displays the nijiwa... similar to the conventional device.
1 center position and orientation flat included.

is detected. As a result, rough positional information of wave 1 is known.

Next, when the XYZθ table 2 is driven and positioned to a specific degree of 1!1, the fields of view E and F shown in FIG. 5 can be captured by the first objective image receptor 24 and the second objective image receptor 25, respectively. . Similar to the probe needle position recognition described above, the pattern image of the chip 41 on the wafer 711 is processed, and the XYZ position dimensions and rotation angle of the chip can be calculated. This allows the position of the way to be known with high precision. Here, the amount of deviation between the two is calculated from the position information of the wafer and the position information of the glove needle set earlier, and in the direction of eliminating the deviation i, the pumping tip ( It is possible to accurately position and contact the pad 42 as shown in FIG.

In this embodiment, the following closed-loop positioning operation and even more reliable blobbing operation can be performed. In other words, since the objective image receptor is arranged so that images of the probe needle group and the chip pattern can be captured simultaneously when the probe needle group 12 and the bonding pad 42 are brought into positioning contact, it is possible to g-identify the amount of relative positional deviation with high precision. At the same time, this amount of deviation is fed back to the positioning of the XYzθ table 2 for the chip after the next pitch movement, and here too, simultaneous images of the glove needle and chip pattern are obtained and the amount of deviation is feedback corrected to the next chip in turn. This enables closed-loop positioning operations. These operations are performed by executing the control program 6c of the arithmetic control section 60.

〔Effect of the invention〕

As explained above, according to the present invention, the X
By providing a Yz scan/mechanism section, an optical imaging section that converts the optical image from each image receptor into an electrical signal, and a pattern recognition processing section that performs image processing on the electrical signal to recognize the probe needle size, There is no need to manually detect the position of the probe needle group and teach in the position information, and there is no need for visual inspection under a microscope. Therefore, it is possible to speed up the work and reduce blobbing errors. In particular, by arranging the objective image receptor so that an optical image in which the probe needle group and the chip pattern overlap and using a closed loop method, it is possible to further improve the reliability of the blobbing operation.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing an example of a conventional wafer prober device of the company; Fig. 2 is a configuration diagram showing an embodiment of the present invention; Fig. 3 is a plan view for explaining the field of view of the objective image receptor; The drawings are a configuration diagram showing another embodiment of the present invention, FIG. 5 is a plan view for explaining the field of view of the objective image receiving aperture, and FIG. 6 is a plan view showing a state in which blobbing is completed. 1...Ts x-ha, 2...XYZθ table, 6
... Arithmetic control unit, 6a ... Control program,
6b...Position detection work control program, 6c-
Conflict - Arithmetic control program, 15a. 24.25-...One objective image receptor, 18,34.35...
...Optical imaging section, 22.40...Pattern recognition processing section, 26.27.Optical system XYZ scanning mechanism section,
34.35...Optical imaging unit, 40...Pattern recognition processing unit. Agent Patent Attorney Akio Takahashi Figure 1 Figure 3

Claims (1)

[Claims] A wafer prober device that performs blowing by bringing a group of probe needles into contact with a wafer to be blown on a wafer to be blown on an an XYZ scanning mechanism unit that performs relative scanning motion in the directions; an optical imaging unit that optically processes the optical surface 11I from each of the image receptors and converts it into an electrical signal; and a pattern recognition unit that processes all images of the electrical signals and recognizes a probe needle image. A processing section, and a calculation control section that drives and controls the XYZ scan mechanism section and the pattern recognition processing section, and recognizes and calculates the dimensional variation and average position of the probe needle group from the recognition result information by the pattern recognition processing section. Characteristic way 2: prober device. 2. The objective image receptor is arranged so that an optical image in which the probe needle group and the chip pattern on the wafer to be blown are overlapped can be obtained. 2. The wave prober device according to claim 1, further comprising a closed loop that feeds back positional relationship information of the optical image of the glove needle group and the chip pattern to the drive output of the 1xyzθ table.