JPH05333100A - Probe device - Google Patents

Abstract

PURPOSE:To obtain a small, high-speed probe device capable of very accurately accomplishing the movement of probing without making a device for accuracy correction complicated. CONSTITUTION:A wafer 22 is aligned by a CCD 52 provided in an alignment bridge 50. Then, probing measurement is carried out by a probe 12 provided in a probe card 10, and marking is done to a bad chip by a scratch marker 62 provided in a marking bridge 60. In these processes, the wafer 22 is moved and scanned by X table 30 and Y table 40. The alignment bridge 50 and the marking bridge 60 can be allowed to take refuge to a noninterference area not interfering with other members in carrying out the probing measurement, and thereby the miniaturization of the device and the improvement of moving accuracy of the device can be done.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe device for inspecting the electrical characteristics of IC chips and the like.

[0002]

2. Description of the Related Art A probe device of this type, for example, a probe device for a semiconductor wafer, is provided before dicing a wafer.
It is used for the purpose of measuring electrical characteristics such as a circuit function of an IC chip on a wafer in a wafer state. in this case,
Since the IC chips are arranged in the shape of a substrate on the semiconductor wafer, it is necessary to perform probing measurement while scanning each IC chip stepwise on a two-dimensional plane, and for this scanning, very high accuracy is required. You must use an XY table. Further, when performing such probing measurement, it is required to simultaneously perform processing such as fine alignment, that is, accurate alignment of the wafer, marking on a defective chip, and inspection, that is, inspection of needle marks on pads. Conventionally, an apparatus as shown in FIG. 5 has been used to perform such processing. This device includes a base 300, an X table 310, and a Y table 32.
0, a fine alignment unit 330, a probing unit 340, and a marking unit 350. When performing probing measurement of the wafer 360 with this apparatus, first, the fine alignment unit 330 is used.
Position, and probing unit 340 for probing measurement and marking unit 350.
The defective chip is marked with, and finally, the fine alignment unit 330 performs inspection and finishes the process. Also in fine alignment, defective chip marking, and inspection processing, as in the probing processing, it is necessary to scan the IC chips arranged on the wafer in the shape of a substrate.
As shown in FIG. 5, a highly accurate XY table is shared under all units. Therefore, the base 300
Becomes longer in the Y direction, and this tendency is further strengthened by the recent increase in the diameter of the wafer.

By the way, with the recent high integration of LSI, the area of the core portion in the LSI chip is reduced,
The number of input / output signals is increasing due to the complexity of processed signals. As a result, there is a situation in which the area of the input / output section in the LSI chip, that is, the pad section cannot reduce the area of the entire chip. Therefore, in the sub-micron process, the pad size, which was 100 μm square in the past, is becoming 60 μm square.

[0004]

In the semiconductor wafer probe apparatus, it is the most important technical problem to keep the movement accuracy of the XY table within the standard range, for example, 8 μm or less. Further, this standard value is required to be more strict as the pad size is reduced. On the other hand, due to the increase in the diameter of the wafer, the tendency of increasing the size in the Y direction is further strengthened in the conventional apparatus.
The increase in length in the Y direction reduces the rigidity of the base in the Y direction, deteriorates the machining accuracy of the ball screw for driving the Y table, increases the cumulative error of the ball screw, and increases the attitude error of the Y table on the base. As a result, the movement accuracy of the XY table deteriorates. Then, in order to prevent the movement accuracy from deteriorating and satisfy the above-mentioned standard value, a device for correcting the error is required, but the lengthening in the Y direction complicates the correction device and the correction method. ,
It was complicated. Further, the conventional probe device has a drawback that it occupies a large area in a clean room where the cost per unit area is high.

Therefore, an object of the present invention is to complicate a device for correcting the movement accuracy of the probing within the above-mentioned standard range while dealing with the increase of the pad size and the diameter of the wafer in the submicron era. Another object of the present invention is to provide a small-sized and high-speed probe device that can be achieved without causing any trouble.

[0006]

A probe device according to the present invention includes a probe card having a large number of contact terminals for performing electrical probing measurement by contacting an element to be measured in a body to be measured, Imaging means for adjusting the position of the measured object before the electrical probing measurement, and when performing the electrical probing measurement and the position adjustment,
A two-dimensional scanning means for scanning the measured object in a two-dimensional plane, an area facing the probing area necessary for performing electrical probing measurement on all the measured elements in the measured object, and an electrical probing measurement. And a means for moving the imaging means between a non-interference area where the imaging means does not interfere with other members.

[0007]

According to the apparatus of the present invention, the object to be measured is moved in the probing area by the two-dimensional scanning means in order to measure all non-measurement inhibitions in the object to be measured with respect to the probe card. When using the image pickup means, the image pickup means is moved from the insensitive area to the area facing the probing area, and then the object to be measured is similarly moved by the two-dimensional scanning means. Therefore, the scanning area for position adjustment of the measured object and the scanning area for electrical probing measurement overlap or coincide with each other,
It is possible to reduce the size of the device and significantly improve the scanning movement accuracy.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the probe device according to the present invention will be specifically described below with reference to the drawings.

First, the structure of this embodiment will be described.

FIG. 1 is a sectional view of this embodiment, and FIG. 2 is a three-dimensional representation thereof. However, in FIG. 2, the head plate 16, the marking bridge 60, and the guide shaft 6 are shown.
4, the post 66 is not shown.

A probe needle 12 is provided on the probe card 10. When measuring an object to be measured, such as a wafer 22, with the probe card 10, the probe needle 12 is used.
By making contact with the bonding pad of the IC chip on the wafer 22, it becomes possible to electrically measure the IC chip in the wafer state. The probe card 10 is detachably fitted into the insert ring 14,
The insert ring 14 is fixed to the head plate 16.

Below the probe card 10, a base 70 is provided.
Is provided on the Y table 40 and the X table 30.
And the mounting tables 20 are sequentially stacked. This table 20
A wafer 22, which is the object to be measured of the probe card 10, is placed on the wafer. The mounting table 20 is the X table 3
It is fixed at 0. The mounting table 20 is the X table 30.
With the Y table 40 and the Z-direction drive mechanism (not shown) provided therebelow, it is possible to move independently in the X, Y, and Z directions. A drive mechanism for the X table 30 and the Y table 40 in this case is shown in FIG. First,
A case where the X table 30 is moved in the X direction in FIG. 3 will be described.

A motor 32 is provided on the Y table 40. A ball screw 34 is connected to the motor 32, and the ball screw 34 is rotationally driven by the motor 32. Since the ball screw 34 is connected to the X table 30 having a nut (not shown) to be screwed, the rotational drive of the motor 32 is converted into linear drive in the X direction. As a result, the mounting table 20 together with the X table 30
It is possible to move in the X direction along the linear guide 36 provided on the Y table 40.

The same method is used to move the Y table 40 in the Y direction. That is, the rotational drive of the motor 42 is converted into linear drive in the Y direction by the ball screw 44 and the nut that is screwed on the Y table 40. This allows the X table 3 as well as the Y table 40.
0 and the mounting table 20 can be moved in the Y direction along the linear guide 46 provided on the base 70.

A base 70 is provided below the Y table. The support 56 is fixed to the base 70, and the support 5
A guide shaft 54 is fixed to 6. The alignment bridge 50 moves the wafer 22 along the guide axis 54.
It is provided so that it can freely move in and out in the direction of arrow A in FIG. As a result, the alignment bridge 50 can be retracted to an area that does not interfere with other members (hereinafter referred to as a non-interference area) when the wafer 22 is measured by the probe card 10. Alignment bridge 5
At the tip of 0, an image pickup device for performing fine alignment and inspection of the wafer 22, for example, C
A CD 52 is provided. In this case, although not shown in the figure, the alignment bridge 50 is provided with two CCDs of high magnification and low magnification.

A support 66 is provided on the other side of the support 56 of the base 70.
Is fixed. The support shaft 66 is provided with a guide shaft 64, and the marking bridge 60 is provided along the guide shaft 64 so as to be able to move in and out in the direction of arrow B in FIG. As a result, the marking bridge 60 can be retracted to the non-interference area when the wafer 22 is measured by the probe card 10. A defective IC is attached to the tip of the marking bridge 60.
What marks the chip, for example, a scratch marker 62 is attached, and the scratch marker 62 is provided with a scratch needle 64. Marking can be performed by mechanically scratching the defective IC chip with the scratch needle 64. ． Next, the operation of this embodiment will be described.

When the wafer probing inspection is performed in this embodiment, the following steps are performed: wafer loading, pre-alignment, fine alignment, probing, defective chip marking, specification, and wafer unloading. ..

First, the wafer 22 is a transfer arm (not shown).
Then, the wafer is loaded from a wafer cassette (not shown) and carried out to a pre-alignment stage (not shown). The pre-alignment stage pre-aligns the wafer 22 by, for example, aligning the orientation flat. Next, the wafer 2 is transferred by the transfer arm.
2 is carried out from the pre-alignment stage to the mounting table 20, where the fine alignment of the wafer 22 is performed. In the fine alignment, the centering of the wafer, the orthogonal axis alignment of the wafer, and the thickness inspection of the wafer are performed, which will be described below.

When performing fine alignment, first,
The alignment bridge 50 moves along the linear guide 54, and the CCD 52 is preferably set immediately below the center of the probe card 10. With this setting, an operation area of the XY table necessary for probing and measuring all the IC chips on the wafer 22 (hereinafter referred to as a probing area) and an operation area of the XY table necessary for performing fine alignment. Can be approximately the same. Therefore, it is possible to minimize the movement stroke required for the XY table, and it is possible to reduce the size of the apparatus and increase the movement accuracy described later.

Next, the wafer 22 is centered. The centering of the wafer 22 is performed by the low magnification CCD 52. First, the wafer 2 on the mounting table 20 is moved by the X table 30.
2 moves in the X direction, and the coordinates of the intersections of the left and right edges of the scanning line of the low-magnification CCD 52 and the wafer 22 are measured at two points. Next, the wafer 22 on the mounting table 20 is moved in the Y direction by the Y table 40, and thereafter, the coordinates of the intersection of the scanning line and the wafer edge are measured at two points in the same manner as described above. The center coordinates C _{2 of the} wafer are measured from the coordinates of the four points thus measured, and from this and the known center coordinates C ₁ of the mounting table 20, the deviation of the wafer center from the mounting table center | C ₁ -C ₂ | Is measured and centered.

Next, the high-magnification CCD 52 is used to align the orthogonal axes of the wafer. The orthogonal axis alignment is performed, for example, by measuring the line connecting the pads in the IC chip with the high-magnification CCD 52 and aligning this line with the Y axis of the device. Finally, the thickness of the wafer is measured to correct the Z direction. The thickness is measured, for example, by measuring five points on the wafer 22 with an electrostatic sensor (not shown).

The fine alignment is completed as described above, and the alignment bridge 50 retracts to the non-interference area.
After that, the probe card 10 electrically measures the IC chip on the wafer 22. At this time, the mounting table 20 is
The X table 30, the Y table 40, and a Z-direction drive mechanism (not shown) move the X-, Y-, and Z-directions, so that IC chips on the wafer can be sequentially measured. Therefore, the alignment bridge 50 needs to be retracted to the non-interference area as described above so as not to interfere with the operation of these members.

When the measurement by the propping is completed, the marking bridge 60 is moved along the guide shaft 64, and the scratch marker 62 is preferably set right below the probe card 10 so as to face substantially the center thereof. By setting in this way, the probing area and the XY required for marking as described above.
The operating areas of the table can be made almost the same, and X
It is possible to minimize the moving stroke required for the Y table. Next, the chip which has been determined to be defective by the above-mentioned propping measurement is marked by the scratch marker 62.

When the marking is completed, the marking bridge 60 retreats to the aforementioned non-interference area. After that, the alignment bridge 50 moves again, and the high precision CCD
52 is set on the wafer 22 and inspection is performed. In this inspection, for example, IC
Inspect whether the needle on the chip pad is within the specified range. When this inspection is completed, the wafer 22 is returned to the original wafer cassette by the transfer arm, and the operation is completed.

As described above, according to the present embodiment, all the processes such as probing, fine alignment, defective chip marking, and inspection are collectively performed on one stage, that is, below the probe card 10. You can And, by thus unipolarizing the processing stage, a great advantage is brought about. This will be described below.

In the conventional probe device, a stage for fine alignment and inspection and a stage for marking defective chips are provided separately from the stage for probing. In this case, the X table 30 and the Y table 4 in each stage
Since 0 is shared, it is necessary to increase the movement stroke in the Y direction, which causes the base and Y table to move in the Y direction.
It became necessary to increase the size in the direction. In particular, with the recent increase in the diameter of wafers, the tendency toward longer size has become stronger.
By the way, in the probe device, it is a major technical problem to keep the movement accuracy of the XY table within a standard range, for example, within 8 μm. In particular, the number of input / output pads per chip has increased due to high integration of ICs, but the chip area needs to be reduced.
The pad size, which was square, is also becoming 60 μm square.
As a result, there is a demand for higher movement accuracy in the XY directions during probing. However, in the conventional probe device, since the length in the Y direction is physically large as described above, the movement accuracy is deteriorated, and the device for correcting this is complicated. This will be described below.

First, when the base 70 is lengthened in the Y direction, the rigidity of the base 70 in the Y direction becomes weak and the base 70 bends by its own weight, which deteriorates the movement accuracy in the Y direction. In particular, this device requires micrometer accuracy, so
This effect is large, and in order to prevent this, the base 70
Of the base 70
It led to a significant increase in weight, that is, an increase in cost.

Further, if the base 70 is enlarged, the processing accuracy of the base 70 and the ball screw 44 is deteriorated. In particular, in the ball screw 44, accuracy errors due to backlash accumulate as the ball screw becomes longer, which causes a larger cumulative error between both ends. Although the cumulative error generated in this way can be corrected, the larger the error, the more complicated the apparatus for performing the correction in order to achieve the standard value described above. Further base 7
If 0 becomes long, it becomes necessary to correct not only such an axial error but also a posture error such as yawing or pitching. In addition, the deformation due to thermal expansion becomes large, and heat countermeasures are required. As a result, the correction device becomes more complicated and complicated, and the cost and size of the device increase.

The enlargement of the base 70 affects not only the accuracy of the apparatus but also the throughput of the apparatus. That is, since the ball screw 44 becomes longer, the ball screw 44
And the moment of inertia of the ball screw 44 increases. Therefore, the Y table 4 during the propping operation
The stop speed of 0 becomes slow, and the high speed operation of the device is disturbed,
Processing throughput will fall.

The problems of the conventional device described above can be solved by this embodiment. In other words, like this example,
By performing processing such as propping, fine alignment, marking on a defective chip, and inspection under the probe card in a polarized manner, it is possible to prevent the base 70 from being lengthened, and thereby the movement accuracy of the XY table. Will be greatly improved. And, with respect to the allowable movement accuracy of the XY table, which is becoming more and more difficult due to the high integration of the LSI, without complicating or complicating the correction device,
It will be possible to respond. Further, since the moment of inertia can be reduced by reducing the weight of the ball screw 44, the processing speed of the device can be increased, and the downsizing of the base 70 can also reduce the size of the device. Become.

Next, a modification of this embodiment will be described.

FIG. 4 shows this modification from above. This modification is an alignment bridge 50 of FIG.
Is a modification of the alignment arm 100 of FIG. The alignment arm 100 includes a telescopic shaft 200 that expands and contracts in the Z direction, a lifting block 210, a swingable swing arm 220, an alignment head 230, and a CCD 2.
40. The lifting block 210 is a telescopic shaft 2.
00 and is vertically movable in the Z-axis direction along the expansion / contraction axis 200. A swing arm 220 is connected to the lifting block 210, and an alignment head 230 is fixed to the swing arm 220. The alignment head 230 is provided with two low-magnification and high-magnification CCDs 240. This alignment arm 100
When performing the probing measurement of the wafer 22, FIG.
As indicated by the solid line, the retreat is in the upper area in the Z direction and in the non-interference area outside the head plate 16. In the case of performing fine alignment and inspection processing on the wafer, the alignment head 230 is set so as to come directly below the probe card 10 as shown by the dotted line in FIG. Processing is performed. In this modified example, the telescopic shaft 20
Although the alignment head 230 can be moved up and down by providing 0, this function is not always necessary, and a fixed shaft that does not expand and contract can be used.

The present embodiment is not limited to the above embodiment, and various modifications can be made within the scope of the present invention.

For example, the object to be measured of the apparatus according to the present invention is
The object to be processed is not limited to the wafer 22, and another object to be processed, such as an LCD substrate, which requires probing may be used. Further, in FIG. 1, two alignment bridges 50 and two marking bridges 60 are provided, but it is also possible to provide only the alignment bridge 50 among them.

Further, the CCD 52 and the scratch marker 6
The setting position of 2 is not limited to just under the probe card, and may be set at any position in the probe area. This is because if the probe area and the operation area of the XY table required for finalization and marking have an overlapping portion, the moving stroke of the XY table can be reduced at the overlapping portion.

[0036]

As described above, according to the present invention, the image pickup means can be moved between the area facing the probing area and the area not interfering with other members during probing, so that the position can be adjusted during probing. The scanning areas of the object to be measured can be made to coincide with or overlap with each other at the time of alignment, the device can be downsized, and the movement stroke can be shortened.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of a probe device to which the present invention is applied.

FIG. 2 is a schematic perspective view with a part of the apparatus of FIG. 1 omitted.

FIG. 3 is a plan view showing a lower portion of the apparatus of FIG. 1 below a mounting table.

FIG. 4 is a plan view for explaining a modified example of the mechanism for moving the image pickup means.

FIG. 5 is a plan view showing a lower side of a mounting table of a conventional probe device.

[Explanation of symbols]

 10 probe card 20 mounting table 22 wafer 30 X table 40 Y table 50 alignment bridge 52 CCD 54 guide shaft 60 marking bridge 62 stretch marker 64 guide shaft

Claims (3)

[Claims] 1. A probe card having a large number of contact terminals for performing electrical probing measurement by contacting a device under test inside the device under test, and adjusting the position of the device under test before the electrical probing measurement. Image pickup means for performing the measurement, a two-dimensional scanning means for scanning the measured object in a two-dimensional plane when performing electrical probing measurement and position adjustment, and electrical measurement for all measured elements inside the measured object. A means for moving the imaging means between an area facing a probing area necessary for performing probing measurement and a non-interference area where the imaging means does not interfere with other members during electrical probing measurement. A probe device characterized by the above. 2. Marker means for marking a defective element in the measured object determined to be defective as a result of the electrical probing measurement by using the two-dimensional scanning means, the probing area, and the non-interference area. 2. The probe apparatus according to claim 1, further comprising: a unit that moves the marker unit between the probe unit and the unit. 3. The position at which one or both of the image pickup means and the marker means are arranged in the probing area is a position facing substantially the center of the probe card. Or the probing device according to 2.