JPH07297242A - Probe method and the device - Google Patents

Abstract

PURPOSE:To perform accurate marking on an IC chip decided detective in a probe device for bridging a probe into contact with an electrode pad of a chip to be examined on an object to be examined and electrically measuring the chip. CONSTITUTION:A probe card 51 with a probe needle 5 is provided opposing a transfer region of a wafer place pedestal 31 on a Z transfer part 3 movable in X, Y, Z directions. First imaging means 4 is provided in the Z transfer part 3, while second imaging means 42 is movably provided in an X direction between the wafer place pedestal 31 and the probe needle 5, and both imaging means 4, 42 are focused with respect to each other and a specific point on a wafer W is recognized by the second imaging means 42 and the probe needle 5 and marking means 7 are recognized by the first imaging means, respectively. Thus, as a relative position of each part can be grasped, the place pedestal 31 is transferred so that an IC chip decided defective comes to the marking position to perform marking for the defective IC chip.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe device and a probe method.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process, after a wafer manufacturing process is completed and an IC chip is completed in a wafer, a probe by a probe device is used to check a short circuit, an open pattern of an electrode pattern and an input / output characteristic of the IC chip. Electrical measurement called a test is performed, and the quality of the IC chip is determined based on the state of the wafer. Then the wafer is I
After the chip is divided into C chips and a good IC chip is packaged, a predetermined probe test is performed to judge the quality of the final product.

As shown in FIG. 6, the conventional probe apparatus is arranged above the wafer mounting table 1 which is movable in the X, Y, Z, and θ directions, corresponding to the electrode pad arrangement of the IC chips in the wafer W. A probe card 12 having arranged probe needles 11 is arranged. Then, the mounting table 1 is moved by stepping so that the electrode pads of the IC chip in the wafer W and the probe needle 11 are brought into contact with each other in sequence, and the test head 14 makes an electrical measurement through the contact ring 13.

When it is determined that the IC chip is defective, it is necessary to mark the defective chip on the surface of the defective chip in order to distinguish it from other normal chips later. An inker for dropping ink on the surface of the is provided as a marking means. If the array density of probe needles is low, an inker is provided between the probe needle groups, and if the chip is determined to be defective, the inker is placed at the measurement position of the chip, that is, with the electrode pad in contact with the probe needle. It is only necessary to activate the ink to drop the ink on the chip, but as the device pads become finer and finer, and the electrode pads become finer, the number of them increases and the arrangement interval becomes narrower, the density of probe needles becomes smaller. It becomes high, and it becomes difficult to provide the inker in the array region of the probe needles.

Therefore, if the inker cannot be provided in the array region of the probe needles 11, the inker 15 is placed in a region away from the probe needles 11 as shown in FIG. After the inspection of all the chips above, the operator manually moves the mounting table 1 while looking at the camera 16 to bring the defective chip to a position below the inker 15, and marks the defective chip. There are various methods for this manual operation. For example, a target is formed on a wafer, and the mounting table 1 is moved so that the target is positioned under a camera (not shown). Placement table 1 according to the amount of movement
There are known methods such as moving.

[0006]

However, the wafer W is
Since many IC chips of the same shape are arranged vertically and horizontally in the same repeating pattern on the top, the work of relatively positioning the defective chip under the inker is very troublesome, and a chip other than the defective chip is mistakenly erroneously placed. May be located under the inker. If a chip other than the defective chip is marked, the defective chip is not marked, so that the defective chip is passed to the next step. In this case, for example, the wafer is divided into individual IC chips and then packaged, and an originally unnecessary work such as inspection of the packaged chips and investigation of the cause of the inspection result is performed.

The present invention has been made under such circumstances, and an object thereof is to provide a probe device capable of reliably marking a chip to be inspected, which is determined to be defective. is there.

[0008]

According to a first aspect of the present invention, an object to be inspected in which a plurality of chips to be inspected are arrayed is mounted, X,
A mounting table movable in the Y and Z directions, a probe card provided with a probe for contacting and inspecting the electrode pad of each of the chips to be inspected, and marking means for marking a defective chip to be inspected. In the probe apparatus having the above-mentioned, the step of imaging the probe and the marking means by the imaging means that moves integrally with the mounting table and recognizing the positions of the probe and the marking means in the X and Y directions, and moving the mounting table. To electrically contact the electrode pad of the object to be inspected with the probe to electrically measure the chip to be inspected to determine pass / fail, and to position the probe and the marking means in the X and Y directions recognized by the imaging means. Controlling the mounting table based on this, and moving the chip to be inspected, which has been determined to be defective, to the marking position of the marking means. And wherein the door.

According to a second aspect of the present invention, a mounting table is provided on an XYZ table which can be moved in the X, Y and Z directions, and an object to be inspected on which a plurality of chips to be inspected are arranged is placed on the table. In a probe device for electrically measuring an inspected chip by contacting an electrode pad and a probe of the inspected chip, a marking means for marking the inspected chip determined to be defective, and provided on the XYZ table, An image pickup means for picking up the image of the probe and the marking means, a position in the X and Y directions of the XYZ table when the image of the probe is picked up by the image pickup means, and an X of the XYZ table when the marking means is picked up, When a chip to be inspected is determined to be defective, a storage unit that stores the position in the Y direction and X based on the data stored in the storage unit. It controls the Z table, and characterized in that it comprises a control unit for moving the defective chip to the marking position of the marking means.

[0010]

Operation: Image pickup means that moves integrally with a mounting table on which an object to be inspected is mounted, for example, XY that can move in the X, Y, and Z directions.
The probe and the marking means are respectively imaged by the image pickup means provided on the Z table, the respective positions of the probe and the marking means are obtained at the X and Y coordinates managed by the control system of the XYZ table, and the marking means for the probe is obtained. Find the relative position of. Then, the electrode pads of each chip to be inspected of the object to be inspected are brought into contact with the probe to perform an electrical measurement, and when it is determined to be defective, the inspection of all the chips of one object to be inspected is finished immediately thereafter. After that, the chip to be inspected, which is determined to be defective based on the relative position, is moved to the marking position of the marking means. Therefore, the defective chip can be surely marked.

[0011]

1 is a perspective view showing an outline of the whole embodiment of the present invention, and FIG. 2 is a block diagram showing a combination of the structure and the block circuit of the embodiment of the present invention. In FIG. 1, reference numeral 21 is a Y stage, which can be moved in the Y direction along the Y guide rail 23 on the base 22, and 24 is an X stage, which is moved in the X direction along the X guide rail 25 on the Y stage 21. It is configured to be mobile. Reference numerals 26 and 27 denote ball screws, respectively, which rotate the respective ball screws by a motor M2 in the X and Y directions (motors in the X direction are not visible in the figure), for example, step motors to move the X and Y stages 21 and 24, respectively. Drive with high precision. In FIG. 2, these parts in the X and Y directions are collectively shown as an X and Y assembly 20.

On the X stage 24, there is provided a Z moving section 3 which is placed or moved in the Z direction. That is, this Z
The moving unit 3 can move in the X, Y, and Z directions.
The Z moving unit 3 includes a high-magnification first image pickup unit 4 having an image pickup unit for picking up an image of the inspection unit and the operation unit, for example, a probe and a marking unit, which will be described later, which are enlarged and equipped with a CCD camera. A low-magnification camera 41 for picking up an image of the probe and the marking means in a wide area is provided. It should be noted that the desired image may be taken in by performing a switching operation with one image pickup means.

A wafer mounting table 31 is provided on the Z moving section 3 so as to be movable in the θ direction (rotatably in the circumferential direction). A probe card 51 attached to the insert ring 50 is arranged as an inspection means above the moving area of the mounting table 31.
Is detachably provided on a head plate 52 corresponding to a top plate of the apparatus body. In the probe card 51, probe needles 5 which are probes are arranged corresponding to the arrangement of the electrode pads on the wafer W which is the object to be inspected. A test head 6 is provided on the probe card 51 via a contact ring 53.
A data storage unit 61 that stores measurement data based on an electric signal transmitted from the probe card 5, a determination unit 62 that measures the quality of the IC chip that is the measurement target based on the measurement data, and the like are provided.

Between the probe card 51 and the mounting table 31, there is provided a moving body 43 with a second image pickup means 42 for picking up an image of an object to be inspected, for example, a wafer W, which is, for example, a CCD camera.
And is movably provided in the X direction. Further, on the side of the probe card 51, a marking means for marking a defective chip, for example, a marking means 7 for dropping ink through a nozzle 71 is provided as an operating means. The control system of the probe apparatus according to the embodiment will be described below. The control system includes a central processing unit 8, an image processing unit 81, a memory 82, an encoder 83, a motor control unit 84, and the like. Image processing unit 81
Has a function of processing the image signals from the first and second image pickup means 4 and 42 and comparing them with the images stored in advance. The memory 82 is for storing data such as each position of the probe needle 5, the electrode pad, and the marking means 7 on the coordinates managed by the control system. The encoder 83 is provided in each motor that drives the mounting table 31 in the X, Y, and Z directions according to a predetermined program, and actually, the number of pulses in each of the X, Y, and Z directions (rotation of the ball screw). Output).
The motor control unit 84 is for controlling each motor in the X, Y, and Z directions.

Next, the operation of the above embodiment will be described. First, after mounting the wafer W to be inspected on the mounting table 31,
As shown in FIG. 3A, the second image pickup means 42 is positioned near the probe needle 5, and the Z moving section 3 is controlled so that the first image pickup means 4 and the second image pickup means 42 have the same focal point. To do. This focusing is performed by, for example, providing a target T formed by depositing a metal film on a transparent thin glass plate on the Z moving unit 3 side, which is movable back and forth with respect to the focal position of the second image pickup means 42. be able to.

Next, as shown in FIG. 3 (b), the X and Y stages 21 and 24 are moved so that the second imaging means 42 images a predetermined specific portion on the wafer W, for example, a plurality of specific points. Then, as shown in FIGS. 3C and 3D, the probe needle 5 and the marking means 7 are imaged by the first imaging means 4. In these imaging steps, for example, as shown in FIG. 4A, a wide area is first imaged in the low magnification mode (the camera 41 is used in the case of the second imaging unit 4), and then as shown in FIG. This is performed by imaging a narrow area in the magnification mode and controlling the XY stages 21 and 24 so that the target point is located at the center of the screen.

In the above steps, the Z moving unit 3 when the image pickup means 4 and 42 are in focus and when each part is imaged
The positions on the coordinates in the X, Y, and Z directions (coordinates managed by the control system) are stored in the memory 82 by the central processing unit 83 based on the pulse signal from the encoder 83.

In this way, the first and second imaging means 4 and 42 are focused on each other, and the first imaging means 4 images the probe needle 5 and the marking position, and the second imaging means 42.
When the image of the wafer W is picked up by, it is equivalent to the image pickup of each part by a common image pickup means, and the relative position of each part can be obtained. Then, based on the relative position of each part, X, Y,
Although the alignment in the Z direction is performed, before that, the alignment of the mounting table 31 in the θ direction is performed so that the alignment of the probe needles 5 and the alignment of the electrode pads of the wafer W are aligned.

Taking the position of the probe needle 5 as an example,
When the first and second imaging means 4 and 42 are in focus with each other (FIG. 3A) and when a specific point on the wafer W is imaged (FIG. 3B), the probe needle 5 is imaged. When (Fig. 3
The positions of the respective Z moving portions 3 in (c)) in the X direction are set to X _a , X
Assuming _b and X _c , the amount of movement of the Z moving unit 3 from the coordinate origin in order to bring the specific point of the wafer W into contact with the probe needle 5 is X = X _b + X _c −X _a . However, similar calculations may be performed in the Y and Z directions.

If such alignment is performed, for example, a plurality of specific points on the wafer W are set, and the position of the electrode pad is determined from the position data of each specific point to absorb errors such as expansion and contraction and distortion of the ball screw to some extent. Since it is possible to accurately align the electrode pad and the probe needle, the amount of movement of the Z moving portion 3 in the Z direction at the time of contact between the electrode pad and the probe needle 5 and marking of a defective chip is also automatically performed in advance. However, the present invention is not limited to such a probe device.

After the position and the amount of movement of each part are obtained in this manner, the Z moving part 3 is controlled to move in the X, Y and Z directions as shown in FIG. The pad and the probe needle 5 are relatively brought into contact with each other, and this operation is sequentially performed on each chip, and the test head 6 electrically measures each IC chip, and the measurement result is stored in the data storage unit 61.
Store in. Then, the marking unit 7 marks the IC chip judged to be defective by the judgment unit 62. This marking is performed, for example, after the IC chip is determined to be defective and before the measurement of the next IC chip is performed, or after the measurement of all the IC chips of one wafer W is completed. In the central processing unit 8, the address information of the defective IC chip is sent from the test head 6, and in order to recognize which chip on the wafer W is defective, the current position of the Z moving unit 3 and the memory 82 already exist. The position of the Z moving unit 3 is controlled via the motor control unit 84 based on the marking position and the position of the probe needle 5 stored in FIG.
As shown in (b), the defective IC chip is positioned directly below the nozzle 71 of the marking means 7. Then, the ink, for example, is dropped on the IC chip from the nozzle 71 of the marking means 7, and a mark, for example, M is attached to the defective IC chip as shown in FIG. 5C.

According to the above-described embodiment, the tip of the wafer W, the probe needle 5 and the nozzle 71 of the marking means 7 are recognized by the common image pickup means, as described above, so that each chip on the wafer W is recognized. And probe needle 5 and nozzle 71
The relative position to the tip of the IC chip can be accurately grasped, and therefore, the IC chip determined to be defective can be automatically and surely marked. As a result, it is not necessary to perform a troublesome marking operation by the operator, which is conventionally performed, and there is no possibility that a normal IC chip is erroneously marked and a defective IC chip is sent to the next process as a normal one.

As described above, in the present invention, the second image pickup means for picking up the image of the wafer W is fixed, the relative position between the fixed position and the probe needle is grasped in advance, and the first and second image pickup means are The present invention may also be applied to a probe device in which, for example, one point on the wafer W is imaged by the second imaging means without performing focusing, and each electrode pad is aligned with the probe needle. The probe is not limited to the probe needle extending obliquely downward from the printed circuit board of the probe card as in the above-described embodiment, but a so-called vertical needle extending vertically from the guide plate may be used. It may be a gold bump or the like formed on a flexible film.
The chip to be inspected is not limited to the IC chip and may be a liquid crystal display.

[0024]

As described above, according to the present invention, it is possible to reliably mark a chip to be inspected, which is determined to be defective.

[Brief description of drawings]

FIG. 1 is a perspective view showing an outline of a probe device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a structure and a block circuit of a probe device according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram showing mutual focusing of a first imaging unit and a second imaging unit, imaging of a wafer W, and imaging of a probe needle.

FIG. 4 is an explanatory diagram showing a screen in an imaging process of a probe needle.

FIG. 5: Contact between probe needle and wafer and defective IC
It is explanatory drawing which shows the mode of marking of a chip.

FIG. 6 is a side view showing a conventional probe device.

[Explanation of symbols]

 21 Y stage 24 X stage 3 Z moving part 31 Mounting table W Semiconductor wafer 4 First imaging means 42 Second imaging means 5 Probe needle 51 Probe card 7 Marking means 71 Nozzle

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[Procedure amendment]

[Submission date] June 17, 1994

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 4]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 5]

[Figure 6]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location G01R 31/28 (72) Inventor Shinji Akaike 1238, Kitashitajo, Fujii-cho, Nirasaki-shi, Yamanashi 1 Tokyo Electron Yamanashi Co., Ltd.

Claims (2)

[Claims] 1. A mounting table on which an object to be inspected, in which a plurality of chips to be inspected are arranged, is movable, and which is movable in X, Y, and Z directions.
In a probe device having a probe card provided with a probe for contacting an electrode pad of each of the chips to be inspected and inspecting, and a marking means for marking a defective chip to be inspected, integrated with the mounting table. Image of the probe and the marking means by the moving image pickup means to recognize the position of the probe and the marking means in the X and Y directions, and the mounting table is moved to electrically connect the electrode pad and the probe of the DUT. To determine whether the chip to be inspected is good or bad, and the mounting table is controlled based on the positions of the probe and the marking means in the X and Y directions recognized by the image pickup means, and it is determined to be defective. And a step of moving the inspected chip to the marking position of the marking means. 2. An XYZ table capable of moving in X, Y, and Z directions is provided with a mounting table, and an object to be inspected in which a plurality of chips to be inspected are arranged is placed on the mounting table, and an electrode pad of the chip to be inspected. And a probe device for contacting the probe to electrically measure the chip to be inspected, a marking means for marking the chip to be inspected that is determined to be defective, the probe and the marking means provided on the XYZ table. And an XY image when the probe is imaged by the imaging means.
A storage section for storing the X and Y direction positions of the Z table and the X and Y direction positions of the XYZ table when the marking means is imaged; and the storage section when the chip to be inspected is determined to be defective. And a control unit that controls the XYZ table based on the data stored in the table to move the defective chip to the marking position of the marking unit.