JPH09199553A - Probing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method which, when a plurality of electrodes are positioned with respect to associated contactors of a probe corresponding to the electrodes, can bring the contactors into reliable contact with the respective electrodes by positioning tip ends of all the contactors at centers of the associated electrodes without any need of experience or labor. SOLUTION: Gravity centers of electrode pads provided at 4 corners of an IC chip T are found as gravity coordinate points P1 to P4 . Then on the basis of these gravity coordinate points P1 to P4 , a gravity center of the 4 electrode pads is found as a gravity coordinate point gravity PC of the IC chip T. Thereafter, gravity centers of probes 20A associated with the electrode pads are found as gravity coordinate points N1 to N4 . Then on the basis of the gravity coordinate points N1 to N4 of the probes 20A, a gravity center of the 4 probes 20A is found as a gravity coordinate point NC of a probe card. Thereafter, the gravity coordinate point PC of the IC chip T is positioned at the gravity coordinate point NC of the probe card.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the inspection of the electrical characteristics of an object to be inspected by electrically contacting an electrode of the object to be inspected such as a semiconductor wafer with a contact using a probe device. The present invention relates to a probe method for aligning an electrode of a device under test and a contactor.

[0002]

2. Description of the Related Art In general, a probe apparatus is provided with, for example, a loader section for carrying a semiconductor wafer and a prober section for inspecting the electrical characteristics of the semiconductor wafer delivered from the loader section. The loader unit includes a cassette mounting unit for mounting semiconductor wafers in cassette units, a transfer mechanism for transferring the semiconductor wafers to the loader unit, and a orientation flat as a reference in the process of transferring the semiconductor wafers through the transfer mechanism. And a sub-chuck for aligning (pre-aligning) the semiconductor wafer. Further, the probe unit includes a main chuck that receives and places the pre-aligned semiconductor wafer from the transfer mechanism, an alignment mechanism that accurately aligns the semiconductor wafer on the main chuck, and an electrode of the semiconductor wafer after the alignment. A probe card having a probe needle that makes electrical contact with the pad is provided.

Further, a test head is rotatably arranged on the prober section, and this test head is electrically connected to a probe card, and a signal from a tester is transmitted through a test head and a probe needle to an electrode pad of a semiconductor wafer. Then, the IC chip formed on the semiconductor wafer is inspected.

By the way, in order to accurately inspect a large number of IC chips on a semiconductor wafer, it is necessary to perform a positioning operation for surely bringing the electrode pad of the semiconductor wafer into contact with the probe needle. Therefore, conventionally, for example, the electrode pad P and the probe needle are aligned by aligning the center of one probe needle corresponding to the center of one reference electrode pad.

[0005]

However, in the case of the above-mentioned conventional probe method, the reference electrode pad and the probe needle corresponding thereto are aligned at one location, so that, for example, FIG. In the electrode pad P ₃ farthest from the reference electrode pad P ₁ as shown in (a) of FIG. _{3, the} corresponding probe needle N ₃ is offset to the end of the electrode pad P ₃ as shown in FIG. There was a problem that the position was greatly displaced from the center. Such a positional deviation is a difficult technique to attach a plurality of probe needles N to a probe card as designed, and even if accuracy is required for the attachment, the tip of the probe needle N may be slightly displaced from its original position (usually It is difficult to avoid doing a few μ). When the semiconductor wafer is inspected in such a misaligned state, the needle weakens over time during the inspection and the probe tip of the most misaligned probe needle may come off the electrode pad.

Therefore, as shown in FIG. 10A, when the positional deviation of the probe needle N ₃ on the electrode pad P ₃ is large, the above-mentioned alignment is performed in order to reduce the above-mentioned positional deviation. After that, the electrode pad P ₂ below the electrode pad P ₁ is used as a reference electrode pad, and the probe needle N ₂ corresponding to the electrode pad P ₂ is used as described above. _I was trying to align with the center of ₂ . Also in this case, if the probe needle N ₄ is largely displaced in the electrode pad P ₄ or the like farthest from the electrode pad P ₂ , another electrode pad P ₃ ,
Using P ₄ as a reference pad, similar alignment was sequentially performed. When the positional deviation cannot be adjusted satisfactorily by such an operation, the operator's intuition and experience had to be adjusted so that any probe needle N would be near the center of the corresponding electrode pad P. Therefore, there has been a problem that a great deal of labor is imposed on the operator when the electrode pad P and the probe needle N are aligned.

The present invention has been made to solve the above problems, and requires no skill or labor when aligning a plurality of electrodes with a contactor such as a probe needle corresponding to each electrode. An object of the present invention is to provide a probe method in which the tips of all the contacts are aligned near the centers of the corresponding electrodes, and each contact can be reliably brought into contact with each electrode.

[0008]

According to a probe method of a first aspect of the present invention, the mounting table is moved in the X, Y, Z and θ directions to detect an object to be inspected mounted on the mounting table. A probe method for preliminarily aligning each electrode with each contactor when electrically inspecting the object to be inspected by electrically contacting the plurality of electrodes with a plurality of contactors corresponding to these electrodes In the step of obtaining the center of gravity of each electrode, the step of obtaining the center of gravity of the plurality of electrodes based on the center of gravity of each electrode, the step of obtaining the center of gravity of the tip of each contact, It has a step of determining the center of gravity of the plurality of contacts based on the center of gravity, and a step of aligning the center of gravity of the plurality of electrodes and the center of gravity of the plurality of contacts obtained in each step. It is a thing.

According to a second aspect of the probe method of the present invention, the mounting table is moved in the X, Y, Z, and θ directions, and a plurality of electrodes of the object to be inspected are mounted on the mounting table. When performing an electrical inspection of the object to be inspected by electrically contacting a plurality of contacts corresponding to these electrodes, in a probe method for pre-aligning each electrode and each contact,
The method has a step of imaging the tips of the contacts with the first imaging means, and a step of imaging the electrodes with the second imaging means, and based on the image obtained by the first imaging means. Determining the center of gravity of the tip of each contactor; determining the center of gravity of the plurality of contacts based on the center of gravity of each tip; and each electrode based on the image obtained by the second imaging means. Of the center of gravity of each of the electrodes, the step of determining the center of gravity of the plurality of electrodes based on the center of gravity of each of the electrodes, the center of gravity of the plurality of electrodes obtained in each of the steps and the center of gravity of the plurality of contacts And a process.

According to a third aspect of the probe method of the present invention, the mounting table is moved in the X, Y, Z, and θ directions, and a plurality of electrodes of the object to be inspected are mounted on the mounting table. When performing an electrical inspection of the object to be inspected by electrically contacting a plurality of contacts corresponding to these electrodes, in a probe method for pre-aligning each electrode and each contact,
A step of imaging the tips of the contacts by the first imaging means, and a step of imaging the electrodes by the second imaging means;
Aligning the optical axis of the first image pickup means with the optical axis of the second image pickup means, and determining the center of gravity of the tip of each contactor based on the image obtained by the first image pickup means. A step of obtaining, a step of obtaining the center of gravity of the plurality of contacts based on the center of gravity of each of the tips, and a step of obtaining the center of gravity of each of the electrodes based on an image obtained by the second imaging means,
Characterized by having a step of determining the center of gravity of the plurality of electrodes based on the center of gravity of each electrode, and a step of aligning the center of gravity of the plurality of contacts and the center of gravity of the plurality of electrodes obtained in each of the steps It is what

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on the embodiments shown in FIGS. First, a probe device to which the present invention is applied will be described. The probe apparatus 10 used in the present embodiment is, for example, as shown in FIGS. 1 and 2, a cassette mounting portion 11 on which a semiconductor wafer W stored in a cassette C is mounted, and the cassette mounting portion 11 of the cassette mounting portion 11. A loader unit 13 including tweezers 12 for carrying the semiconductor wafer W, and a prober unit 14 for inspecting the semiconductor wafer W carried through the tweezers 12 of the loader unit 13.
And a controller 15 for controlling the prober unit 14 and the loader unit 13, and a display device 16 which also serves as an operation panel for operating the controller 15.

Further, the loader section 13 is provided with a sub-chuck 17 for pre-aligning the semiconductor wafer W on the basis of the orientation flat. Therefore, tweezers 12
Conveys the semiconductor wafer W from the cassette C, pre-aligns the semiconductor wafer W on the sub chuck 17,
The semiconductor wafer W is transferred to the prober unit 14.

Further, the prober unit 14 has a main chuck 18 for moving the X-, Y-, Z-, and .theta.
An alignment mechanism 19 for aligning the semiconductor wafer W placed thereon and a probe card 20 having a plurality of probe needles 20A for electrically inspecting the semiconductor wafer W aligned by the alignment mechanism 19 are arranged. It is set up. The probe card 20 has a prober unit 14
It is installed and fixed in the approximate center of the ceiling. A test head 21 is rotatably arranged on the prober unit 14,
A probe card 20 and a tester (not shown) are electrically connected via a test head 21 that swivels on the prober unit 14, and a predetermined signal from the tester is transmitted through the test head 21 and a probe needle 20A to the main chuck. The signal is transmitted to the electrode pads of the IC chip of the semiconductor wafer W on 18 and the electrical inspection of the chip is sequentially performed.

Next, the main chuck 18 is driven by the drive mechanism 22.
Is configured to move in the X, Y, Z and θ directions on the base 23. As shown in FIG. 3, the drive mechanism 22 includes an X table 24 that moves in the X direction, a Y table 25 that moves in the Y direction, and a lifting unit 2 that moves up and down in the Z direction.
6 and a rotation mechanism (not shown) that rotates in the θ direction. The X table 24 moves via a ball screw 24B and a motor (not shown) according to a guide rail 24A extending in the X direction, and the amount of movement is detected by an encoder (not shown). The Y table 25 moves along a guide rail 25A extending in the Y direction via a ball screw 25B and a motor 25C, and the amount of movement thereof is detected by an encoder 25D.

Further, as shown in FIG. 3, a fixed plate 27 is horizontally attached to the elevating part 26, and the fixed plate 2
First image pickup means 28 composed of a CCD camera of high magnification on 7
Is provided, and the probe needle 20A is provided by the first imaging means 28.
The needle point of is captured in an enlarged manner, and the image is displayed on the display screen 16A of the display device 16. Also, the fixed plate 2
A low-magnification CCD adjacent to the first imaging means 28
A camera 29 is provided, and the CCD camera 29 photographs the array of probe needles 20A in a wide area and displays the image on the display screen 16A of the display device 16. Further, on the fixed plate 27, a target 30 which is orthogonal to the optical axis of the first image pickup means 28 and focuses the light is arranged, and the target 30 moves forward and backward with respect to the focus position of the first image pickup means 28. I am doing it. This target 3
0 is, for example, a glass plate and a diameter 140 deposited on the surface thereof.
The first imaging means 28 recognizes an image by using this metal thin film as a reference pattern, and the target 30 at the position is used as a focusing surface.

Further, an alignment bridge 19A constituting an alignment mechanism 19 is arranged in the prober portion 14, and the alignment bridge 19A follows the main chuck 18 according to a guide rail 19B extending in the X direction as shown in FIGS. 1 and 2, for example. It moves in the area between the probe card 20 and the probe card 20. The alignment bridge 19A is provided with a second image pickup means 31 capable of switching between high magnification and low magnification. The second image pickup means 31 enlarges the semiconductor wafer W on the wafer chuck 18 at a low magnification or a high magnification. Each image is taken and displayed on the display screen 16A of the display device 16. Further, the focusing surface of the second image pickup means 31 is obtained by image-recognizing the metal thin film of the target 30 similarly to the first image pickup means 28. The alignment mechanism 19 includes the alignment bridge 19A, the second image pickup means 31, the first image pickup means 28, the target 30, and the second image pickup means 31.
It is a positioning mechanism including the above.

Then, the controller 15 of the probe device 10 includes a central processing unit 32, as shown in FIG.
An image processing unit 33, a memory 34, and a motor control unit 35 are provided to drive and control the drive mechanism 22 and the like of the probe device 10. The central processing unit 32 transmits a control signal to the motor control unit 35 to control the motor of the drive mechanism 22 according to a program registered in the memory 34, or receives a pulse signal from the encoder to control X, Y, The amount of movement in the Z and θ directions is calculated, the position data of the main chuck 18 and the like are calculated, and the calculation result and other data are stored in the memory 34.
I am registered to. The image processing unit 33
The image pickup signals of the first and second image pickup means 28 and 31 are received and image-processed, and the processed image is displayed as a picked-up image on the display screen 16A, registered as image data in the image memory, or already stored in the image memory. The registered image data is compared with the captured image, or the first and second image capturing means 2 are used.
It is determined whether or not the picked-up images 8 and 31 are in focus.

Next, one embodiment of the probe method of the present invention for aligning the probe needle 20A and the electrode pad P of the semiconductor wafer W in the present probe device 10 will be described with reference to FIGS. As shown in FIG. 2, the alignment method of the present embodiment is performed on the semiconductor wafer W received from the tweezers 12 of the loader unit 13 by the main chuck 18 of the prober unit 14 as shown in FIG. This is a method of aligning the center of gravity P _c of the electrode pads P _{1 to} P _{4 at} the four corners with the center of gravity N _{c of} the four probe needles 20A corresponding to these electrode pads P _{1 to} P ₄ . Such alignment of the centers of gravity can be performed according to the flow shown in FIG.

First, the center of gravity of the probe card 20 is obtained. A low-magnification CCD camera 29 is used as the driving mechanism 22.
Is moved below the probe card 20, and the CCD camera 28 is moved up and down to a position where the probe tip of the probe needle 20A coincides with the focusing surface of the CCD camera 28, and the needle tip is recognized at a low magnification (S1). As shown in FIG. 7A, the high-magnification first imaging unit 28 is moved below the probe card 20 by the drive mechanism 22, and the probe needle at the upper left of FIG. 8A in the four corners of the probe card 20. The needle tip of 20A is recognized and imaged at a high magnification, and the image is aligned with the + mark at the center of the display screen 16A as shown in FIG. 9A (S).
2). The center of gravity of the needle tip of the probe needle 20 is calculated by the central processing unit 32 based on the pulse signal of the encoder corresponding to the movement amount of the main chuck 18 at that time,
The barycentric coordinates N ₁ (X _N1 , Y _{N 1} , Z _N1 ) are obtained as shown in (S3), and the barycentric coordinates N ₁ are registered in the memory 34 via the central processing unit 32. Then, the first imaging means 28
Moves in the counterclockwise direction directly below the other three probe needles 20A, and the center of gravity of each probe needle 20A is moved to the center of gravity coordinates N ₂ (X _N2 , Y _N2 , Z _N2 ), N ₃ (X _N3 , Y _N3 ,
Z _N3 ) and N ₄ (X _N4 , Y _N4 , Z _N4 ) are sequentially obtained in the same manner as described above, and these barycentric coordinates N ₂ , N ₃ , N ₄ are stored in the memory 34 via the central processing unit 32. register. Thereafter, based on these four barycentric coordinates, the barycentric coordinates of the four probe needles 20A, that is, the barycentric coordinates N _{C of the} probe card 20.
(X _NC , Y _NC , Z _NC ) is calculated by the following equations (1) to (3) (S4), and the barycentric coordinates are registered in the memory 34. These barycentric coordinate data are as shown in FIG. X _NC = (X _N1 + X _N2 + X _N3 + X _N4 ) / 4 (1) Y _NC = (Y _N1 + Y _N2 + Y _N3 + Y _N4 ) / 4 ... (2) Z _NC = (Z _N1 + Z _N2 + Z _N3 + Z _N4 ) / 4 ... (3)

Then, the optical axes of the first and second image pickup means 28 and 31 are aligned with each other as shown in FIG. 7B, and their positions are obtained. That is, after the semiconductor wafer W is placed on the main chuck 18 in the prober unit 14 by the tweezers 12 from the loader unit 13 (S5), the alignment bridge 19A
Moves in the area between the main chuck 18 and the probe card 20 and stops at a fixed position below the probe card 20 (S6). Then, the target 30 advances above the first image pickup means 28, the first image pickup means 28 is focused on the center of the target 30 to recognize the metal thin film, and the second image pickup means 31 is focused on the center of the target 30. When the metal thin film is recognized in accordance with, the first and second imaging means 2
The optical axes of 8 and 31 coincide with each other (S7). The reference coordinates (X ₀ , Y ₀ , Z ₀ ) of the intersection of the focusing surface and the optical axis at this time are calculated from the position of the main chuck 18, and the calculated value is registered in the memory 34. By detecting the amount of movement of the first image pickup means 28 at this time through an encoder, the positional relationship between the respective barycentric coordinates and the reference coordinates can be obtained on the coordinates.

After that, the center and diameter of the semiconductor wafer W are obtained by using the second image pickup means 31 (S8). That is, after the target 30 is retracted from the focusing surface of the first image pickup means 28, the wafer chuck 18 is moved by the drive mechanism 22,
During this movement, the second image pickup means 31 detects, for example, three end portions of the semiconductor wafer W, and based on the detection result, the center and the diameter of the semiconductor wafer W are determined based on the moving distance of the main chuck 18. The calculation is performed at 32, and the calculated value is registered in the memory 34. Subsequently, the scribe line of the semiconductor wafer W is overviewed at a low magnification by the second image pickup means 31, and the X and Y axes of the semiconductor wafer W are rotated in the θ direction to align with the X and Y axes of the X and Y tables 24 and 25 ( S9). As a result, the IC chip T of the semiconductor wafer W is aligned with the index feeding direction.

Further, when the main chuck 18 is moved by the drive mechanism 22, the semiconductor wafer W on the main chuck 18 is image-recognized by the second image pickup means 31 having a low magnification, and the picked-up image is registered in advance in the image processing section 33. A matching chip image is searched for by comparing with a characteristic chip image for position alignment (S10). When the matching tip image is found, the magnification is switched to a high magnification, and the enlarged tip image is compared with the previously registered characteristic tip image in the same manner as S8, the matching tip image is found, and the image is used for needle matching. The image is registered in the image processing unit 33 as an image.
When a matching chip image is found, the semiconductor wafer W is moved in the middle, up, down, left, and right directions by an integer multiple of the chip size known in advance from the image, and during this movement, the second
While the semiconductor wafer W is being imaged by the imaging means 31, the characteristic chip images registered in advance are compared with the image processing unit 33, and the matching chip images are sequentially captured and registered in the image processing unit 33, and the main chuck at that time is captured. The central processing unit 32 calculates the movement distances θ of the semiconductor wafer W of each IC chip T in the X and Y directions from the coordinate values of 18, and stores the calculated θ in the memory 34 (S11).

Next, the IC formed on the semiconductor wafer W
The center of gravity of the tip T is calculated (S12). That is, as shown in FIG. 7C, the electrode in the IC chip T corresponding to the probe needle 20A found in S2 from the imaged image of the high-magnification chip found in S11 (see FIG. 9B). Since the distance of the pad P is registered in advance and is known, as shown in FIG. 8B, in the central processing unit 32, based on this distance and the current position coordinates of the main chuck 18, the electrode pads P at the four corners are formed. The barycenters of _{1 to} P ₄ are respectively barycentric coordinates P
₁ (X _P1 , Y _P1 , Z _P1 ), P ₂ (X _P2 , Y _P2 , Z _P2 ), P
₃ (X _P3 , Y _P3 , Z _{P 3} ) and P ₄ (X _P4 , Y _P4 , Z _P4 ), which are calculated and registered in the memory 34, and then based on these four barycentric coordinates. The center of gravity of the four electrode pads P, that is, the center of gravity coordinates P _C (X _PC , Y _PC , Z _PC ) of the IC chip T are obtained by the following equations (3) to (6), and the center of gravity coordinates are registered in the memory 34. These barycentric coordinate data are shown in FIG.
(B) of FIG. X _PC = (X _P1 + X _P2 + X _P3 + X _P4 ) / 4 (4) Y _PC = (Y _P1 + Y _P2 + Y _P3 + Y _P4 ) / 4 (5) Z _PC = (Z _P1 + Z _P2 + Z _P3 + Z _P4 ) / 4 ... (6)

After obtaining the center of gravity of the probe needle 20A (center of gravity of the probe card 20) and the center of gravity of the four electrode pads P (center of gravity of the IC chip T) as described above, X of the center of gravity of the four probe needles 20A is obtained. , Y direction coordinate values (X _NC , Y _NC ) and the center of gravity of the four electrode pads P in X and Y direction coordinate values (X _NC
The semiconductor wafer W is moved in the horizontal direction so that ( _PC , Y _PC ) coincides with each other (S13). That is, based on the barycentric coordinates N _C (X _NC , Y _NC , Z _NC ) of the probe card 20 and the barycentric coordinates P _C (X _PC , Y _PC , Z _PC ) of the IC chip T, the central processing unit 32 horizontally sets the two. The distance is calculated, and a control signal based on the calculated value is sent from the central processing unit 32 to the motor control unit 35.
To drive the drive mechanism 22 via the motor controller 35 to move the main chuck 18 in the horizontal direction,
The drive mechanism 22 is stopped at a position where the center of gravity of the IC chip T is vertically aligned with the center of gravity of the probe card 20.

Further, the probe card 2 is provided in the central processing unit 32.
The height at which the four probe needles 20A come into contact with the four electrode pads P is calculated from the coordinate value Z _NC of the center of gravity of 0 in the Z direction and the coordinate value Z _PC of the center of gravity of the IC chip T (S14). , The control signal based on the calculated value is transmitted from the central processing unit 32 to the motor control unit 35, and the drive mechanism 22 is drive-controlled via the motor control unit 35 to move the main chuck 18 upward to move the IC chip T. Each electrode pad P of is brought into contact with the corresponding probe needle 20A (S15). At this time, the main chuck 18 is overdriven by a slight distance to ensure electrical contact between the electrode pad P and the probe needle 20A.

As described above, according to this embodiment,
Based on the process of obtaining the barycenters of the electrode pads P at the four corners of the IC chip T as barycentric coordinates P ₁ , P ₂ , P ₃ , P ₄ , and these barycentric coordinates P ₁ , P ₂ , P ₃ , P ₄ The step of obtaining the center of gravity of the four electrode pads P as the center of gravity coordinates P _C of the IC chip T, and the probe needles 2 corresponding to each electrode pad P
The center of gravity of the needle tip with the electrode pad P of 0A is the center of gravity coordinate N ₁ ,
N _2, N _3, a step of determining as N _4, barycentric coordinates _{N 1, N 2, N 3} , barycentric coordinates of the N probe card 20 the center of gravity of the four probe needles 20A based on ₄ of these probes 20A a step of determining the N _C, because it has a process of aligning the center of gravity coordinates N _C of the center of gravity coordinates P _C and the probe card 20 of the IC chip T obtained in these steps, respectively a plurality of probe needles 2 0A When aligning with the corresponding electrode pad P, even if the probe tips of the probe needles 20A are slightly displaced from their original positions, or the positions of the electrode pads P are slightly displaced from their original positions. Also, each probe needle 20A can be gathered in the vicinity of the center of gravity of the corresponding electrode pad P, and all probe needles 20A and these can be easily and reliably corresponded to without requiring skill. It is possible to make sure contact with the corresponding electrode pad P.

Further, according to this embodiment, in addition to the above steps, a step of imaging the needle tips of the four probe needles 20A by the first imaging means 28, and a step of imaging the probe tips 20A of the four probe needles 20A by the second imaging means 31. Since it has the step of imaging the corresponding four electrode pads P, the center of gravity of the probe card 20 and the center of gravity of the IC chip T can be obtained by aligning the imaging screen with the center of the display screen 16A.

Further, according to the present embodiment, in addition to the above steps, there is a step of aligning the optical axis of the first image pickup means 28 with the optical axis of the second image pickup means 31, so that the main chuck 18 is driven. It is possible to perform highly accurate alignment without being affected by the thermal influence of the ball screw or the like of the mechanism 22.

In the above embodiment, the probe card 20 is used.
After the center of gravity of the IC chip T is obtained, the coincidence points of the optical axes of the first and second image pickup means 28 and 31 are obtained, and then the center of gravity of the IC chip T is obtained, but this order may be mixed with each other. Further, although the probe method in the case of inspecting the semiconductor wafer W has been described in the above embodiment, the probe method of the present invention can be applied to the probe method in the case of inspecting the substrate for liquid crystal display.

[0030]

According to the invention described in claim 1 of the present invention, no skill or labor is required for aligning a plurality of electrodes with a contactor such as a probe needle corresponding to each electrode. It is possible to provide a probe method in which the tips of all the contacts are aligned near the centers of the corresponding electrodes, and each contact can be reliably brought into contact with each electrode.

According to the second aspect of the present invention, the center of gravity of the plurality of contacts and the center of gravity of the plurality of electrodes of the object to be inspected corresponding to the image pickup screen are displayed on the display screen of the display device. It is possible to provide a probe method capable of determining

According to the third aspect of the present invention, there is provided a probe method capable of performing highly accurate alignment without being affected by the thermal influence of the drive mechanism of the mounting table. be able to.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a probe device applied to a probe method of the present invention, and is a partial cross-sectional view showing a state in which a front surface of a prober unit is broken.

FIG. 2 is a plan view showing the inside of the probe device shown in FIG.

FIG. 3 is a perspective view showing a main chuck and an alignment mechanism of the probe device shown in FIG.

4 is a block diagram showing a control system of the probe device shown in FIG. 1. FIG.

FIG. 5 is a plan view schematically showing a state in which the probe tip of the probe needle is aligned with the electrode pad of the IC chip of the semiconductor wafer by the probe method of the present invention.

FIG. 6 is a flowchart showing an embodiment of the probe method of the present invention.

7 is an operation explanatory view showing an operation of the main chuck and the like when performing alignment according to the flowchart shown in FIG.

FIG. 8A is a coordinate showing the center of gravity of four probe needles,
(B) is a coordinate indicating the center of gravity of the electrode pad of the semiconductor wafer corresponding to the four probe needles shown in (a).

9A is a front view showing a display screen showing an imaged image of a probe needle, and FIG. 9B is a display screen showing an imaged image of an electrode pad of a semiconductor wafer corresponding to the probe needle shown in FIG. 9A. FIG.

10 (a) and 10 (b) are diagrams showing a state in which the probe tips of probe needles are aligned with the corresponding electrode pads by using the conventional probe method.

[Explanation of symbols]

18 main chuck (mounting table) 20 probe card 20A probe (contact) 28 first imaging unit 31 and the second imaging means W semiconductor wafer (object to be tested) P electrode pad N ₁ to N ₄ probe needles of the center of gravity N _C probe the center of gravity of the center of gravity N _C IC chip centroid P ₁ to P ₄ electrode pads of the card

Claims (3)

[Claims] 1. A plurality of electrodes of an object to be inspected mounted on the mounting table and a plurality of contacts corresponding to these electrodes are electrically operated by moving the mounting table in X, Y, Z and θ directions. Step of determining the center of gravity of each electrode in the probe method of preliminarily aligning each electrode with each contactor when electrically inspecting the object to be inspected by contacting each other, and the center of gravity of each electrode. Determining the center of gravity of the plurality of electrodes based on
The step of obtaining the center of gravity of the tip of each contactor, the step of obtaining the center of gravity of the plurality of contacts based on the center of gravity of each tip, the center of gravity of the plurality of electrodes obtained in each step, and the above Aligning the centers of gravity of a plurality of contacts, the probe method. 2. The mounting table is moved in the X, Y, Z and θ directions to electrically connect a plurality of electrodes of the object to be inspected mounted on the mounting table and a plurality of contacts corresponding to these electrodes. Step of imaging the tip of each contact by the first imaging means in a probe method in which the electrodes and the contacts are preliminarily aligned when electrically inspecting the object to be inspected by electrically contacting each other. And a step of imaging each of the electrodes by the second imaging means, and a step of obtaining the center of gravity of the tip end portion of each of the contacts based on the image obtained by the first imaging means; Based on the step of obtaining the center of gravity of the plurality of contacts based on the center of gravity of the tip, the step of obtaining the center of gravity of each of the electrodes based on the image obtained by the second imaging means, and the basis of the center of gravity of each of the electrodes. Steps for obtaining the center of gravity of the plurality of electrodes, and the above steps Probe method characterized by a step of aligning a plurality of the center of gravity and the center of gravity of the plurality of contacts of the electrodes obtained. 3. A plurality of electrodes of an object to be inspected mounted on the mounting table and a plurality of contacts corresponding to these electrodes are electrically operated by moving the mounting table in X, Y, Z and θ directions. Step of imaging the tip of each contact by the first imaging means in a probe method in which the electrodes and the contacts are preliminarily aligned when electrically inspecting the object to be inspected by electrically contacting each other. And a step of imaging each of the electrodes by the second imaging means, and a step of aligning the optical axis of the first imaging means with the optical axis of the second imaging means. The step of obtaining the center of gravity of the tip of each contactor based on the obtained image; the step of obtaining the center of gravity of the plurality of contacts based on the center of gravity of each tip; The step of obtaining the center of gravity of each of the electrodes based on the image, and A probe method comprising: a step of obtaining the center of gravity of the plurality of electrodes based on a center; and a step of aligning the center of gravity of the plurality of contacts and the center of gravity of the plurality of electrodes obtained in each step. .