JPH0567653A - Probing device - Google Patents

Abstract

PURPOSE:To inspect the characteristics of a material to be inspected by an electrical signal of a high frequency and moreover, to inspect efficiently a multitude of the materials to be inspected. CONSTITUTION:In a probe device 24, in which probes 36 of a probe card 34 are brought into contact with electrode pads on a material 26 to be inspected (a semiconductor wafer) and the electrical characteristics of the material to be inspected are inspected by a tester 38 connected to the card 34 via a test head 32, the test head 32 is formed in such a way that the probes 36 are made to slant in directions excluding the upward and down ward directions, and the head 32 is directly attached to the tester. A holding means 28, which brings the material 26 to be inspected into contact with the probes 36 while holding this material 26 to be inspected in such a way as to make the material 26 correspond to these probes 36, is provided to make automatically the inspection.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to improvements in probe devices.

[0002]

2. Description of the Related Art Generally, a probe device is known as a device for measuring the electrical characteristics of a wafer by bringing a stylus of a probe card into contact with an electrode pad or the like of a device under test such as a semiconductor wafer. As a probe device of this kind,
As shown in FIG. 6, a holding unit 4 on which the wafer 2 is placed and which is movable in X, Y, and Z directions, and the holding unit 4.
Of the probe device main body 10 having a probe card 8 provided above the substrate and provided with a stylus 6 for contacting the electrode pad of the wafer 2, and a hinge 12 located on the upper side of the probe device main body 10. It is known that the test head 14 is mounted above the card 8 so as to be capable of being tilted. The test head 14 is connected to a tester (not shown), which is a very heavy object, through a large number of wirings 17. Further, as another device, a structure in which a test head is supported so as to be able to move up and down by a manipulator arranged on the side of the probe device main body 10 instead of the hinge 12 is also known.

In order to inspect the electrical characteristics of the wafer 2 by the prober device constructed as described above, first, the test head 14 is moved to the upper surface side of the probe card 8 and the contact mounted on the test head 14 is moved. 16 is brought into contact with the input / output pin 18 of the probe card 8, and the stylus 6 of the probe card 8 is brought into contact with the electrode pad of the wafer 2 whose position is adjusted by an alignment device (not shown) to be connected to the test head 16. The electrical characteristics are measured by a heavy tester (not shown).

Further, as another probe device, as shown in FIG. 7, a tester 20 and a test head 14 having a weight of several hundred kg, for example, are directly attached to the tester 20. There is known a device in which the length of the cable wiring is shortened and the delay of the signal is reduced to increase the inspection frequency by integrating them.
For example, when inspecting the characteristics of a chip, it is ideally desirable to inspect at a frequency close to the speed at which the chip actually operates, but the frequency at the stylus of the broad card is different from the output frequency of the tester itself. Will drop about one digit due to the length of the cable and the capacity of the stylus. Normal,
A signal delay of, for example, about 1 nsec occurs for a cable length of 10 cm, but this signal delay is minimized to, for example, 5
When performing the characteristic inspection at a high frequency of about 00 MHz, the tester 20 and the tester head 14 having a weight of several hundred kg, for example, are directly attached to the tester 20 and the weight is increased due to the multi-pin structure as described above. The cable length has been shortened. In this case, as shown in the drawing, the tester head 14 is tilted and fixed, and an operator manually attaches one chip at a product level, that is, a packaged chip, to measure the electrical characteristics. Is becoming

[0005]

By the way, in the probe device as shown in FIG. 6, the number of the contacts 16 and the input / output pins 18 is increased along with the miniaturization and complexity of the electrode pad. , The weight of the test head 14 is several tens.
The weight is 0, for example, 800 kg, and the cable 17 connecting the tester and the tester head 14 is extremely thick. Therefore, the hinge mechanism for moving the test head 14 and the like need to have a strong structure, and the structure of the probe device body 10 also needs to have a strong structure.
Increasing the size of the probe device was inevitable. Further, since the cable is bent along the movement of the test head 14 or dragged on the floor for a long distance, an excessive load is applied to the cable, which may lead to an accident such as disconnection of the cable or poor contact.

Further, in the case of conducting the characteristic inspection of the semiconductor wafer as described above, it is ideally desirable to perform the inspection at a frequency close to the speed at which the chip actually operates, but the tester head 14 and the tester are Since the length of the cable 17 to be connected is relatively long, in this cable 17,
For example, a signal delay of about 1 nsec per 10 cm occurred, and the characteristic test could not be performed at a high frequency of about 500 MHz. In particular, it has not been sufficient to perform a characteristic test of a chip that requires particularly high speed, such as a chip used in a supercomputer or the like.

In the probe apparatus shown in FIG. 7, the tester 20 and the tester head 14 are directly attached to each other to shorten the cable length as described above, so that the characteristic test can be performed at a high frequency. The operator manually attaches and detaches the packaged chip 22 for inspection, and has an improvement in that it cannot be mass-produced.
The present invention has been made to pay attention to the above problems and to solve them effectively. An object of the present invention is to provide a probe device capable of performing characteristic inspection efficiently at a high frequency.

[0008]

In order to solve the above problems, the present invention brings a probe head of a probe card into contact with an electrode pad of an object to be inspected to attach a test head to the probe card. In a probe device for measuring the electrical characteristics of the device under test by a tester connected via
The stylus of the test head is formed in a direction other than upward or downward, and holding means for holding the inspected object and making contact with the stylus is formed.

[0009]

Since the present invention is configured as described above, the holding means holds the object to be inspected such as a semiconductor wafer,
The above-mentioned object to be inspected is automatically set on a test head having its stylus formed in a direction other than the downward or upward direction and brought into contact with the stylus of a probe card to perform characteristic inspection.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the probe device according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a side view showing a tester and a probe device according to the present invention, and FIG. 2 is a perspective view showing a state where a tester and a test head are directly attached.
As shown in the figure, the probe device 24 includes a holding means 28 for holding a semiconductor wafer 26, which is an object to be inspected, inclined with respect to the vertical direction, and a horizontal direction so as to face the semiconductor wafer 26. The test head 32 is mainly configured by a test head 32 having a measurement surface 30 formed to be inclined at about 45 °, and a disc-shaped probe card 34 provided at a substantially central portion of the measurement surface 30 of the test head 32. In the center of the probe card 34, a large number of, for example, several hundreds of stylus 36 are implanted so as to come into contact with the electrode pads of the semiconductor wafer 26, and between the semiconductor wafer 26 and the test head 32. It is configured to exchange electrical signals.

The test head 32 is the semiconductor wafer 2
6, an inspection power source, an electric device such as an electrode pad pattern output portion, an input portion for inputting the electrode pad output to the measurement portion, or a stylus 36 and a test head corresponding to the type of the object to be inspected. It has a performance board mechanism including a relay for switching electrical connection with the main body and a precision adjusting capacitor, and the like. For example, in a semiconductor wafer inspection for a supercomputer, about 80
It will weigh as much as 0 kg. And this tester head 3
A box-shaped tester 38 for inspecting the characteristics of the semiconductor wafer 26 is integrally and directly attached to the lower part of 2, and a connection cable (not shown) between this and the tester head 32 is as short as possible. Then, the delay time of the electric signal is minimized. Since this tester 38 accommodates various measuring devices, it can reach 2 to 3 m in length and width.

On the other hand, as shown in FIG. 3, the holding means 28 has a Y-direction guide rail 40 arranged along the Y-direction.
And a Y stage 42 slidably guided to the Y stage 42 and a direction orthogonal to the Y direction, that is, an X stage provided on the Y stage 42.
An X stage 46 slidably guided by an X direction guide rail 44 formed along the direction, and the X stage 46.
The chuck 4 is mainly configured by a chuck 48 that is mounted so as to be able to move up and down (Z direction) and rotate.
The semiconductor wafer 26 can be suction-held on the lower surface of the semiconductor wafer 8 by suction means (not shown). In this case, a small piece 50 for reference positioning is projected on one side of the chuck 48. The alignment piece 50 is formed of, for example, a glass piece on the surface of which a conductive transparent thin film such as a transparent electrode for liquid crystal is applied, and a cross-shaped reference mark 52 of chrome (Cr) is formed at the center thereof. It has been subjected. Further, on the side of the X stage 46, a high magnification and a low magnification can be switched for detecting the XY position of the stylus 36 of the probe card 34 and the Z position of the reference mark 52 of the reference alignment small piece 50. A position detection camera 54 is attached. A drive unit 56 that moves the camera 54 in the Z direction is provided on the side of the camera 54. Further, the entire holding means 28 can be moved in the horizontal direction by a moving mechanism (not shown).

On the measurement surface 30 of the test head 32, as shown in FIG. 2, the TV camera 60 for detecting the chip position on the wafer 26 and the Z position of the reference mark 52 of the reference alignment small piece 50 are provided. An alignment device 64 including a capacitance sensor 62 for detecting is attached.
The TV position of the stylus 36 contacting the chip of the wafer 26 is confirmed by the TV camera 60 of the alignment device 64 to confirm the chip position, and the confirmed chip position information and the stylus confirmed by the position detection camera 54 are confirmed. The stylus is brought into contact with each electrode pad of the wafer 26 by comparing and calculating the position information of 36 by a control means (not shown). In addition, the reference mark 52 of the reference alignment small piece 50 detected by the capacitance sensor 62.
Similarly, by comparing and calculating the Z position of the reference mark 52 and the Z position of the reference mark 52 having the same coordinates detected by the position detection camera 54, it is possible to correct the deviation due to expansion or the like.

On the other hand, as shown in FIG. 4, the probe card 34 has a conductor 68 disposed on a printed circuit board 66.
A plurality of stylus 36 are planted so as to be connected to, and fixed to a head plate 70 provided on the measurement surface 30 of the test head 32 with a fixing screw 76 on an attachment holding body 74 via an insert ring 72. Has been done. At this time, the ground potential supply pad 78 connected to the conductor 68 of the probe card 34 is slidably fitted in the through hole penetrating the holder 74 via the compression spring 80. It is connected to one of the upper sides of the pins 82. Therefore, the elastic force of the compression spring 80 allows the other lower input / output pin 82 to be reliably connected to the contactor 84 of the test head 32, whereby the stylus 3 of the probe card 34 can be connected.
Information exchange of electric signals can be performed between the test head 6 and the test head 32.

Next, the operation of the probe device configured as described above will be described. First, the chuck 48 of the holding means 28 sucks and holds the semiconductor wafer 26, which is the object to be inspected, and moves the chuck 48 to a position opposed to the alignment device 64 to set the chip position of the wafer 26 to the TV of the alignment device 64. It is detected by the camera 60. The detected image information is stored, and alignment is performed by comparison with the image of the detected pattern on the second and subsequent wafers 26. In this way, the wafer 26 whose position has been adjusted by the alignment device 64 faces the probe card 34 while being held by the chuck 48, and is positioned slightly separated therefrom. Then, the chuck 48 moves in the X, Y, and Z directions based on the position information of the stylus 36 previously confirmed by the position detection camera 54, so that the electrode pad of a predetermined chip on the wafer 26 is touched by the probe card 34. The wafer 36 is brought into contact with the needle 36.
The electrical properties of are measured.

In this case, the electric signal for measurement is the tester 3
8, the test head 32, the probe card stylus 36, and the chips in the wafer flow. Especially, in the present embodiment, the test head 32 and the tester 38 are directly attached to each other and the cable length between them is increased. Since it is short, it is possible to reduce the delay amount of the electric signal, and it is possible not only to perform the characteristic inspection at high frequency, but also to eliminate the damage because the cable is not exposed to the outside. be able to. In this way, when the characteristic inspection of one chip is completed, the X, Y stages 46 and 42 and the chuck 48 are appropriately operated to sequentially perform the characteristic inspection of adjacent chips to inspect the entire wafer. finish.

To perform the characteristic inspection of the next wafer, the holding means 28 is slid, for example, in the lateral direction to replace the inspected wafer with the uninspected wafer, and the characteristic inspection is performed in the same manner as described above. Further, by tilting the measurement surface 30 of the test head 32 and integrally forming it with the tester 38 as in the present embodiment, the hinge mechanism required in the conventional device is not required, and the entire device is downsized. be able to. Further, when the semiconductor wafer 26, which is the object to be inspected, is inclined downward as in the embodiment, the oxide film debris or the like on the surface of the electrode pad scraped off by the stylus may adhere to this surface. Therefore, it is possible to prevent deterioration of the quality of the inspection object. Further, in the above-described embodiment, the measurement surface holding the probe card 34 is an inclined surface at an angle of about 45 ° with respect to the horizontal direction. However, this measurement surface does not include a vertically upward direction or a vertically downward direction. Any inclination angle may be set.

Further, in the above embodiment, the so-called performance board function for interfacing the probe card 34 and the inside of the test head 32 is provided in the test head 32, but the present invention is not limited to this. As shown in FIG. 5, this performance board function may be incorporated in the probe card 34. That is, the probe card 34 includes a relay that switches the electrical connection between the stylus 36 and the test head 32 in accordance with the type of the object to be inspected, a capacitor for accuracy adjustment, and the like, and functions as a so-called performance board. And the measurement surface 3 of the test head 32 through the column 90.
It is fixed to 0 with screws or the like. Inside the probe card 34, there are provided so-called many pogo pins 92 that elastically project and retract by interposing elastic members such as springs (not shown) inside, and these pogo pins 92 are attached to the test head 32. The contactor 84 provided is brought into contact with the contactor 84.

With this configuration, the entire cable length can be shortened by the wiring length required to install the performance board, and the delay amount of the electric signal can be reduced accordingly. Therefore, measurement at a higher frequency becomes possible. In addition, not only the characteristic inspection can be performed with an electric signal of high frequency in the device in which the measurement surface is inclined by directly attaching the test head and the tester, but also the inspection is efficiently performed by the automated holding means. Can be done.

[0020]

As described above, according to the present invention, the following excellent operational effects can be exhibited. To provide a probe device compatible with a high-speed test of a tester and a large number of pins, since an object to be inspected can be brought into contact with a stylus of a probe card that is inclined with respect to the tester by a holding means to test the electrical characteristics. You can

[Brief description of drawings]

FIG. 1 is a side view showing a tester and a probe device according to the present invention.

FIG. 2 is a perspective view showing a state where a tester and a test head are directly attached.

FIG. 3 is a perspective view showing a holding means used in the present invention.

FIG. 4 is a cross-sectional view showing a probe card used in the present invention.

FIG. 5 is a side view showing another probe card used in the present invention.

FIG. 6 is a schematic configuration diagram showing a conventional probe device.

FIG. 7 is a schematic configuration diagram showing another conventional probe device.

[Explanation of symbols]

 24 probe device 26 semiconductor wafer (inspection object) 28 holding means 30 measurement surface 32 test head 34 probe card 36 stylus 38 tester 42 Y stage 46 X stage 48 chuck

Claims (1)

[Claims] 1. A probe device in which a probe of a probe card is brought into contact with an electrode pad of an object to be inspected, and an electrical characteristic of the object to be inspected is measured by a tester connected to the probe card via a test head. In, forming the stylus of the test head in a direction excluding upward or downward,
A probe device, characterized in that it is configured to form a holding means for holding the object to be inspected and contacting it with the stylus.