JP2004327805A - Probe equipment and alignment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a probe device and an alignment method for quickly and surely detecting the position of the needle point of the probe of a probe card without erroneously recognizing it, and for shortening an alignment time. <P>SOLUTION: This probe device is provided with an object placing stand moving horizontally and vertically while placing an object to be inspected, a probe card arranged on the object placing plate, an image pickup means to be used for the positioning of the probe of the probe card and the electrode of the object to be inspected, a control means for controlling the image pickup means and the object placing plate so that the electric characteristic inspection of the object to be inspected can be executed under the control of the control means. This probe device is provided with a supporting stand integrally moving with the object placing plate and a sheet for marking the needle trace of the probe is arranged on the supporting stand so that the position of the probe can be detected based on the needle trace by the image pickup means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a probe apparatus and an alignment method, and more particularly, to a probe capable of detecting a probe tip quickly and reliably without erroneous probe tip alignment when performing alignment between an electrode of a device under test and a probe of a probe card. The present invention relates to an apparatus and an alignment method.
[0002]
[Prior art]
The semiconductor processing step includes a step of inspecting an object to be inspected, for example, a wafer on which a plurality of semiconductor devices are formed, in a wafer state. In this inspection process, for example, a probe device is used. The probe device has a loader chamber for transporting a wafer and a prober chamber for inspecting electrical characteristics of the wafer. The prober chamber includes a mounting table on which a wafer is mounted and is movable in the horizontal and vertical directions, and a probe card disposed above the mounting table. When the electrical characteristics inspection of the wafer is performed, the electrode pad for wafer inspection and the probe of the probe card are aligned (alignment) in cooperation with the alignment mechanism when the mounting table moves in the horizontal and vertical directions. ) To make contact, and apply various signals for inspection to the wafer via the probe card.
[0003]
Various methods for aligning the electrode pads of the wafer with the probes have been conventionally proposed. For example, Patent Document 1 proposes a prober that performs alignment using a dummy wafer on which aluminum is deposited. In this case, the dummy wafer is placed on the mounting table (chuck), the chuck moves from the alignment position to the test position, and the chuck rises at the test position to bring the dummy wafer into contact with the probe, thereby causing the probe of the probe to contact the dummy wafer. Make a mark. Thereafter, the chuck returns from the test position to the alignment position, where the fine alignment of the wafer is performed based on the needle trace using the probe needle position measuring device.
[0004]
However, recently, since the chips formed on the wafer have been highly integrated, the stylus pressure by the probe has been reduced, and it has become difficult to form stylus marks on the dummy wafer. Further, every time the probe card is aligned, the dummy wafer must be re-mounted on the chuck. Therefore, a probe device and a probe method that can detect the position of the probe without being affected by the stylus pressure of the probe have been proposed in, for example, Patent Document 2.
[0005]
In the case of the probe method proposed in Patent Literature 2, as shown in FIG. 5A, the focus of the imaging means 2 such as a CCD camera is focused on the tip of the probe 1A of the probe card 1, and at this time, The tip of the probe 1A is detected based on the X and Y coordinate positions of a mounting table (not shown). According to this method, since there is no need to make a needle mark as in the case of the prober of Patent Document 1, even if the needle pressure of the probe 1A is reduced, the needle tip position of the probe 1A can be reliably detected.
[0006]
[Patent Document 1]
JP-A-59-5641 (Claim 1, Claim 2 and page 4, lower left column, line 9 to page 5, upper left column, line 8)
[Patent Document 2]
JP-A-7-110364 (Claim 1, Claim 4 and paragraph [0019])
[0007]
[Problems to be solved by the invention]
However, in the case of the conventional alignment method, there is a problem that the time for adjusting the focus of the imaging unit 2 to the probe tip of the probe 1A becomes longer due to the influence of the reflected light from the probe card 1 and the shape of the probe tip. . When the probe 1A and the electrode pad are brought into electrical contact, the oxide film on the surface of the electrode pad is scraped off by the probe 1A to establish electrical continuity between the probe 1A and the electrode pad. As shown in ()), foreign matter such as shavings D adheres to the needle tip of the probe 1A, and there is a possibility that the needle tip and the foreign matter are erroneously recognized. Further, in the future, if the probe 1A is thinned according to the size of the electrode pad, there is a possibility that the detection of the needle tip by the imaging means becomes more and more difficult.
[0008]
The present invention has been made in order to solve the above-mentioned problems, and it is possible to quickly and reliably detect the position of the probe tip of a probe of a probe card without erroneously recognizing the position, thereby shortening the alignment time. It is an object of the present invention to provide a probe device and an alignment method that can be used.
[0009]
[Means for Solving the Problems]
A probe device according to a first aspect of the present invention includes a mounting table on which an object to be inspected is mounted and which moves in a horizontal direction and a vertical direction; a probe card disposed above the mounting table; An imaging unit used for alignment between a probe and an electrode of the inspection object; and a control unit for controlling the imaging unit and the mounting table, and an electrical characteristic of the inspection object under the control of the control unit. In a probe device for performing an inspection, a support table that moves integrally with the mounting table is provided, and a sheet for attaching a needle mark of the probe is provided on the support table, and the sheet is provided based on the needle mark by the imaging unit. It is characterized in that the position of the probe is detected.
[0010]
A probe device according to a second aspect of the present invention is the probe device according to the first aspect, wherein the support table is attached to the mounting table.
[0011]
According to a third aspect of the present invention, there is provided a probe device according to the first or second aspect, wherein the sheet is detachably provided on the support base. .
[0012]
Further, in the probe device according to the fourth aspect of the present invention, in the invention according to any one of the first to third aspects, a needle mark is formed on the sheet at a needle pressure of 0.1 to 5 g / line. It is characterized by having hardness to be attached.
[0013]
According to a fifth aspect of the present invention, in the probe apparatus according to any one of the first to fourth aspects, the sheet is large enough to be applied a plurality of times without overlapping the needle traces of the probe. The control means has means for storing the position coordinates of the needle trace on the sheet, and means for appropriately setting the difference between the distance between the position coordinates of the needle trace and the position coordinates of the next needle trace. It is characterized by having.
[0014]
Further, according to the alignment method of the present invention, there is provided a mounting table for mounting an object to be inspected and moving in a horizontal direction and a vertical direction, a probe card arranged above the mounting table, Inspection of electrical characteristics of an object to be inspected by using a probe device including an imaging unit used for aligning a probe of a card with an electrode of the object to be inspected, and a control unit for controlling the imaging unit and the mounting table. Moving the supporting table having the sheet integrally with the mounting table to move the sheet below the probe card; and elevating the mounting table to cause the probe trace of the probe to be displayed on the sheet. And a step of obtaining the position coordinates of the probe by imaging the needle trace by the imaging means.
[0015]
Further, in the alignment method according to claim 7 of the present invention, in the invention according to claim 6, a step of appropriately setting a difference in distance between the position coordinates of the needle trace and the position coordinates of the next needle trace, A step of moving the mounting table based on the difference to shift the needle trace from the next needle trace.
[0016]
In the alignment method according to an eighth aspect of the present invention, in the invention according to the sixth or seventh aspect, the step of imaging the needle trace and obtaining the position coordinates of the probe includes: It is characterized by having a process of removing the previous needle mark image data from the image data.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described based on the embodiment shown in FIGS.
As shown in FIG. 1, for example, the probe device 10 of the present embodiment performs a loader chamber 11 for transporting an object to be inspected (for example, a wafer) W and an electrical characteristic inspection of the wafer W adjacent to the loader chamber 11. And a prober chamber 12 for performing an electrical characteristic inspection of the wafer W under the control of the control device. The loader chamber 11 includes a cassette storage section 11B, a wafer transfer mechanism (not shown), and a pre-alignment mechanism (not shown). One wafer W is transferred from the cassette 11C of the cassette storage section 11B to the prober chamber 12 by the wafer transfer mechanism. While the wafers W are transported one by one, the pre-alignment mechanism pre-aligns the wafers W based on the orientation flats or notches of the wafers W.
[0018]
As shown in FIG. 1, the prober chamber 12 has a mounting table 13 on which the wafer W from the loader chamber 11 is mounted and which has an elevating mechanism, and an XY table which supports the mounting table 13 and moves the X and Y directions. 14, a probe card 16 disposed above these two 13, 14 and detachably attached to the head plate 15, and an alignment mechanism 17 for aligning the probe 16 A of the probe card 16 with the electrode pad of the wafer W. And Further, a tester (not shown) is connected to the probe card 16 via a test head T, and an inspection signal from the tester is applied to the wafer W via the test head T and the probe 16A of the probe card 16, and An electrical characteristic test of W is performed. Here, the probe 16A is formed, for example, to have a height of about 100 μm and a diameter of 10 μm or less, and the electrode pad is formed to be, for example, several tens of μm square, and the center-to-center distance is about 100 μm.
[0019]
As shown in FIG. 1, the alignment mechanism 17 has an imaging unit (for example, a CCD camera) 17A for imaging the wafer W and a dummy sheet described later. The CCD camera 17A is attached downward at the center of the alignment bridge 17B. The alignment bridge 17B is supported by a pair of left and right guide rails 17C, and reciprocates between the back of the prober chamber 12 and the probe center (immediately below the center of the probe card 16) according to the pair of guide rails 17C. ing. The CCD camera 17A is connected to a control device via an image processing unit (not shown). The image processing unit processes the captured image of the wafer W, outputs an image signal to the control device, and outputs the image signal to the display device 18. Display each image.
[0020]
As shown in FIG. 2, for example, a support 19 is horizontally extended outward in the radial direction on the upper surface of the mounting table 13, and a dummy sheet 20 is adhered to the upper surface of the support 19. It is detachably attached via an agent or the like. The probe mark 16A is attached to the upper surface of the dummy sheet 20 by piercing the probe 16A, and the position coordinates of the probe tip of the probe 16A in the XY directions are obtained based on the needle mark. Therefore, the dummy sheet 20 may be a sheet having a hardness such that the needle mark 20A of the probe 16A is attached to the upper surface thereof and a sheet having a needle mark remaining thereon. It can be formed of a synthetic resin having a hardness such that the needle mark 20A is attached with a needle pressure of /. As the synthetic resin, a general-purpose resin such as polyolefin and polyvinyl chloride can be used. Further, the dummy sheet 20 is large enough to attach the needle traces of the probe 16A a plurality of times, and is formed to have a thickness sufficient to make the needle traces, for example, 150 μm. The support table 19 is mounted on the mounting table 13 such that the upper surface of the dummy sheet 20 is at substantially the same height as the upper surface of the wafer W mounted on the mounting table 13.
[0021]
The control device according to the present embodiment includes a storage unit that stores various information including a captured image of the dummy sheet 20 and a position coordinate of a needle mark, and a calculation unit that calculates various information stored by the storage unit. For example, the position coordinates of the tip of the probe 16A are obtained based on the needle trace 20A attached to the dummy sheet 20. Further, since the dummy sheet 20 is formed to have a size to take the needle trace 20A plural times, the position of the dummy sheet 20 is shifted each time the needle trace 20A is taken to take the needle trace 20A plural times. Can be taken. When the same probe layout is used, a fixed distance (for example, ΔX = 50 μm and / or ΔY = 50 μm) can be set in advance in the storage unit, and the control device determines the distance based on the needle mark distance difference. By controlling the moving distance of the mounting table 13, the mounting table 13 can be sequentially shifted from the position of the first needle mark 20A to the second and subsequent needle marks 20A so that the plurality of needle marks 20A do not overlap. . Further, the needle mark 20A of the dummy sheet 20 can be confirmed on the screen by displaying the image captured by the CCD camera 17A on the screen of the display device 18.
[0022]
Next, an embodiment of the alignment method of the present invention using the dummy sheet 20 will be described with reference to FIGS. Here, it is assumed that the probe card 16 is attached to the head plate 15, and an unused dummy sheet 20 having no needle mark 20 </ b> A is attached to the support base 19. First, the imaging data on the dummy sheet 20 before the probe 16A is pierced is imaged in advance. FIG. 4A shows an expected needle mark 20A, and the area is shown to be slightly smaller than the dummy sheet 20. However, the dummy sheet 20 is actually sufficiently larger than the area where the needle mark 20A is attached. . At this time, since the field of view of the CCD camera 17A is, for example, about 200 μm × 250 μm, the whole area of the dummy sheet 20 is imaged while the mounting table 13 is moved in the XY directions. Next, the support base 19 is moved so that its center coincides with the probe center (just below the center of the probe card 16). Next, when the mounting table 13 and the support table 19 are raised, the dummy sheet 20 approaches the probe card 16 as shown in FIG. When the support base 19 is further raised, the tip of the probe 16A pierces the upper surface of the dummy sheet 20 as shown in FIG.
[0023]
Next, after lowering the mounting table 13, the CCD camera 17A is advanced to the probe center as shown in FIG. Here, as shown in FIG. 3C, the CCD camera 17A captures an image of the needle mark 20A on the dummy sheet 20 (see FIG. 4A).
[0024]
The captured image is processed by the image processing unit, and is processed by the calculation unit together with the current coordinates of the mounting table 13. By this arithmetic processing, XY position coordinate data of each probe 16A of the probe 16A, shape data of the needle mark 20A, and XY position coordinate data of the needle mark 20A are obtained. The XY position coordinate data of the probe 16A is used when aligning the wafer W with the probe card 16. It is determined from the shape data of the needle trace 20A whether a failure has occurred in the probe 16A. The XY position coordinate data of the needle trace 20A is stored in the storage unit in preparation for the next needle trace detection. At this time, even if foreign matter such as shavings D adheres to the probe 16A, the needle mark 20A can be detected reliably and quickly without being affected by the foreign matter, and the XY position coordinates of the probe tip of the probe 16A can be determined. It can be determined reliably.
[0025]
Thereafter, the wafer W is mounted on the mounting table 13 in the prober chamber 12 from the loader chamber 11 as is conventionally known, and then the diameter and the center of the wafer W are obtained. That is, while the mounting table 13 moves in the X and Y directions, for example, the CCD camera 17A detects three end points of the wafer W, and the center and diameter of the wafer W are set to the moving distance of the mounting table 13 based on the detection result. The calculated value is calculated in the calculation unit of the control device based on the calculated value, and the calculated value is stored in the storage unit. Subsequently, the scribe line of the wafer W is overviewed by the CCD camera 17A, and the wafer W is slightly rotated to align the wafer W in the index feed direction.
[0026]
Further, the mounting table 13 moves to search for a reference electrode pad used for alignment, and the XY position coordinates of the reference electrode pad are stored in the storage unit. After the probe 16A and the reference electrode pad are aligned based on the XY position coordinates of the probe tip of the probe 16A obtained based on the reference electrode pad and the needle mark 20A, the mounting table 13 moves to the inspection start position. First, the device to be inspected is positioned directly below the probe card 16, and when the mounting table 13 is raised by the lifting mechanism at this position, the electrode pads of the device and the corresponding probes 16A are electrically contacted and the wafer W is Conduct electrical characteristics inspection. Thereafter, after the mounting table 13 is lowered, the mounting table 13 performs an electrical characteristic inspection on all devices while sequentially feeding the wafer W by index. After the inspection of the wafer W is completed, the wafer W is returned from the prober chamber 12 to the original place in the loader chamber 11, and the remaining wafers W are inspected in the same procedure.
[0027]
After the inspection of a predetermined number of wafers is completed, or when the inspection of all the wafers W in the cassette 11C is completed and the inspection of the wafer W of the next cassette 11C is started, or when a wafer of a different type having a different probe layout is used. When starting the inspection, the alignment of the probe 16A is performed. This alignment is performed as follows.
[0028]
First, the image data before the probe 16A is pierced this time, that is, image data of the entire area of the dummy sheet 20 where the previous needle trace remains is taken in advance. Next, the tip of the probe 16A pierces the upper surface of the dummy sheet 20 as in the previous case, and the needle mark 20A is attached to the dummy sheet 20 as shown in FIG. In FIG. 4B, a circle with a diagonal line indicates a previous needle mark, and a circle without a diagonal line indicates a current needle mark. As shown in FIG. 4B, when the same probe layout is used several times, the support table 19 is used so that the previous needle mark position and the current needle mark position do not overlap. Can be moved from the probe center by a predetermined moving distance to perform the same operation. In the case of the present embodiment, the needle mark distance differences are ΔX and ΔY in the X and Y directions, respectively, but may be only ΔY.
[0029]
Next, the CCD camera 17A images the needle trace 20A on the dummy sheet 20 in the same manner as the previous time, and from this captured image, the XY position coordinate data of each probe of the probe 16A, the shape data of the needle trace, and the position coordinate of the needle trace 20A. Data is obtained. When obtaining these needle traces 20A, the previous needle trace 20A is not erroneously recognized by performing a process of removing the image data of the previous needle trace stored in the storage unit from the image data of the current needle trace 20A. I have to. Then, the image data of the current needle trace 20A is stored in the storage unit in preparation for the next needle trace detection.
[0030]
After that, the electrical characteristics inspection of the wafer W is performed as in the previous case. The third alignment of the probe 16A is performed in the same manner as in the previous and second previous times. The needle marks 20A on the dummy sheet 20 at this time are shown in FIG. Then, when there is no more space on the dummy sheet 20 for attaching the needle mark 20A, the dummy sheet 20 is replaced with a new dummy sheet 20.
[0031]
As described above, according to the present embodiment, the step of moving the support table 19 having the dummy sheet 20 integrally with the mounting table 13 to move the dummy sheet 20 below the probe card 16, Includes a step of raising the needle mark 20A of the probe 16A on the dummy sheet 20 and a step of imaging the needle mark 20A attached to the dummy sheet 20 by the CCD camera 17A to obtain the position coordinates of the needle tip of the probe 16A. Therefore, the focus of the CCD camera 17A can be easily and reliably focused on the needle mark 20A of the dummy sheet 20, and the position coordinates of the probe tip of the probe 16A of the probe card 16 can be quickly and reliably detected without erroneous recognition. The alignment time can be shortened.
[0032]
Further, since the dummy sheet 20 for taking the needle mark 20A of the probe 16A is provided on the support base 19, even if it is a thin film-like dummy sheet 20 that cannot be conveyed by the conveyance device, it is used as the needle mark. Can be used for detection. Further, there is no need to mount the dummy wafer on the mounting table 13 every time the alignment of the probe 16A is performed as in the case where a dummy wafer is used. Further, since the support table 19 and the mounting table 13 move integrally, the XY coordinates of the tip of the probe 16A can be easily calculated from the XY coordinates of the needle trace 20A.
[0033]
Further, according to the present embodiment, since the dummy sheet 20 having the size to which the needle mark 20A of the probe 16A sticks a plurality of times is used, the alignment operation can be performed a plurality of times with one dummy sheet 20, and the second time can be performed. In the subsequent alignment process, an appropriate distance from the position coordinates of the needle trace 20A of the dummy sheet 20 is set, and a needle trace distance difference from the position coordinates of the second and subsequent needle traces 20A is appropriately set. Moving the mounting table 13 on the basis of the above, the alignment can be performed a plurality of times using one dummy sheet 20, and it is not necessary to replace the dummy wafer for each alignment, thereby improving the inspection throughput. Can be done. Further, since the support table 19 for the dummy sheet 20 is attached to the mounting table 13, it is not necessary to newly provide a mechanism for moving the support table 19.
[0034]
In the above embodiment, the case where the support 19 of the dummy sheet 20 is attached to the upper part of the peripheral surface of the mounting table 13 has been described. It may be attached to. In addition, the material of the dummy sheet 20 is not limited to a synthetic resin and may be any appropriate material as long as the material has a hardness such that a needle mark is formed at a needle pressure of 0.1 to 5 g / line. .
[0035]
【The invention's effect】
According to the first to eighth aspects of the present invention, the position of the probe tip of the probe card can be detected quickly and reliably without erroneous recognition, thereby shortening the alignment time. And an alignment method can be provided.
[Brief description of the drawings]
FIG. 1 is a cutaway front view showing a main part of an embodiment of a probe device of the present invention.
FIG. 2 is a perspective view showing a main part of the probe device shown in FIG.
FIGS. 3A and 3B are explanatory views showing a part of the steps of an embodiment of the alignment method of the present invention using the probe device shown in FIG. 1, and FIG. FIG. 2B is a diagram showing a state where a probe traces a needle mark on a dummy sheet with a probe, and FIG.
4A and 4B are plan views showing a state where needle marks are formed on the dummy sheet shown in FIG. 3 by the alignment method of the present invention, wherein FIG. 4A is a diagram showing a dummy sheet having a first needle mark, and FIG. FIG. 7C is a diagram showing a dummy sheet with a second needle mark, and FIG. 7C is a diagram showing a dummy sheet with a third needle mark.
5A and 5B are explanatory diagrams for explaining an alignment method using a conventional probe device, wherein FIG. 5A is a diagram showing a state where a probe tip of a probe is imaged by a CCD camera, and FIG. FIG. 4 is a diagram illustrating a state where an image of a probe tip is taken.
[Explanation of symbols]
Reference Signs List 10 probe device 13 mounting table 16 probe card 16A probe 17 alignment mechanism 17A CCD camera (imaging means)
19 Support stand 20 Dummy sheet (sheet)
20A Needle mark W Wafer (inspection object)

Claims (8)

A mounting table on which the device under test is mounted and which moves in the horizontal and vertical directions, a probe card disposed above the mounting table, and positioning of the probe of the probe card and the electrodes of the device under test. A probe device comprising: an imaging unit to be used; and a control unit for controlling the imaging unit and the mounting table. The probe device performs an electrical characteristic test on the device under test under the control of the control unit. A probe for providing a trace for attaching the needle trace of the probe on the support, and detecting the position of the probe based on the needle trace by the imaging means. . The probe device according to claim 1, wherein the support table is attached to the mounting table. The probe device according to claim 1, wherein the sheet is detachably provided to the support base. The probe device according to any one of claims 1 to 3, wherein the sheet has a hardness such that a needle mark is formed with a needle pressure of 0.1 to 5 g / piece. The sheet has a size to be applied a plurality of times without overlapping the needle traces of the probe, and the control means includes means for storing position coordinates of the needle traces of the sheet; The probe device according to any one of claims 1 to 4, further comprising means for appropriately setting a difference in distance from the position coordinates of the needle mark. A mounting table on which the device under test is mounted and which moves in the horizontal and vertical directions, a probe card disposed above the mounting table, and positioning of the probe of the probe card and the electrodes of the device under test. When performing an electrical characteristic test of an object to be inspected using a probe device including an imaging unit to be used and a control unit that controls the imaging unit and the mounting table, the support table having a sheet is mounted on the mounting table. Moving the sheet downwardly under the probe card by moving the sheet integrally; and elevating the mounting table to attach the needle trace of the probe to the sheet; and capturing the needle trace by the imaging means. Obtaining the position coordinates of the probe by using the above method. Appropriately setting the difference in distance between the position coordinates of the needle trace and the position coordinates of the next needle trace, and moving the mounting table based on the difference to shift the needle trace and the next needle trace. 7. The alignment method according to claim 6, further comprising the steps of: 8. The method according to claim 6, wherein the step of imaging the needle trace to obtain the position coordinates of the probe includes a process of removing image data of a previous needle trace from image data of a current needle trace. The alignment method as described.

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