JPH08248100A - Method and apparatus for probing - Google Patents

Abstract

PURPOSE: To avoid the damage of a probe due to collision with other article by measuring the position of the article having a fear of collision of the probe by an operator and eliminating the collision of the probe with the other even if its data is not input to the operator in a method for probing which is used if the internal operation of an IC chip is diagnosed by detection an electric signal on an arbitrary wire on an IC chip by using the probe. CONSTITUTION: A non-contact displacement sensor 36 is used, an IC socket 11, and the positions of a package in X and Y directions are obtained, and an area where a probe 22 can be moved without colliding with the socket 11 or the package can be locate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used when a probe is used to detect an electric signal on an arbitrary wiring on an integrated circuit (hereinafter referred to as IC) chip to diagnose the internal operation of the IC chip. The present invention relates to a probing method and device.

[0002]

2. Description of the Related Art For example, in the process of developing an IC,
Although the internal operation of the IC chip in the package is diagnosed,
This is, for example, as shown in FIG.
The window 2 is formed on the substrate to expose the IC chip 3 and the external pin 4
The IC chip 3 is driven by the IC tester via the
This is performed by detecting an electric signal on a predetermined wiring on the chip 3 with a probing device and observing the waveform of this electric signal with an oscilloscope or the like.

In this case, as a probing device, a mechanical probe that can be moved three-dimensionally with respect to the IC chip 3 is conventionally operated under an optical microscope to position it on a predetermined wiring. A probing device was used that was configured to.

[0004]

[Problems to be Solved by the Invention] However, in this way,
In a probing device which is designed to position a mechanical probe using an optical microscope, the wiring on the IC chip 3 is miniaturized, and the wiring to detect an electric signal is determined to position the mechanical probe. Is becoming difficult.

Here, instead of the mechanical probe, a probe having a sensor for detecting the force applied to the probe is used, and the principle of an atomic force microscope (AFM) is used to detect any part of the IC chip 3. Surface shape image (AFM
In the case of obtaining an image), fine wiring that cannot be discriminated by the optical microscope can be discriminated, and the probe can be easily positioned.

However, such a probe has a size of 1 μm.
Very high resolution is required to distinguish the following steps,
In addition, since it is necessary to prevent the pattern from being damaged during scanning, the probe needs to be held by a spring having a small spring constant, and the strength of the probe becomes weak. Window 2
Since the position is not always accurate, the probe may collide with the edge of the window 2 of the package 1 or the like during the scanning of the probe and may be destroyed, and a countermeasure against it is required.

In this case, the operator operates the window 2 of the package 1.
By measuring the position of the object such as the edge of the probe where the probe may collide and inputting the position data, it is possible to avoid collision of the probe with other objects. However, there is a problem in that the burden on the operator increases and a quick test cannot be performed.

In view of the above point, the present invention prevents the probe from colliding with other objects even if the operator measures the position of the object with which the probe may collide and the operator does not input the data. An object of the present invention is to provide a probing method and device capable of avoiding the destruction of the probe due to the collision with other objects.

[0009]

The probing method of the present invention is movable three-dimensionally, detects the surface shape of the IC chip surface for discriminating arbitrary wiring on the IC chip, and detects the surface shape on the IC chip. In a probing device including a probe for detecting an electric signal on an arbitrary wiring, a non-contact displacement sensor is used in advance to measure a region where the probe can be moved, and the measurement result Probing with reference to.

The probing apparatus of the present invention is movable three-dimensionally, detects the surface shape of the IC chip surface for discriminating an arbitrary wiring on the IC chip, and electrically on an arbitrary wiring on the IC chip. The probe includes a probe for detecting a signal and a non-contact displacement sensor that is movable three-dimensionally and that measures a region where the probe can be moved.

[0011]

In the probing method of the present invention, the area in which the probe can be moved is measured in advance by using the non-contact displacement sensor, and the probing is performed with reference to the measurement result. It is possible to prevent the probe from colliding with other objects even if the operator measures the position of the object with which the probe may collide and the operator does not input the data.

In the probing apparatus of the present invention, the non-contact displacement sensor is used and the area where the probe can be moved is measured in advance so that the position of an object where the probe may collide is determined by the operator. Can be measured and the probe can be prevented from colliding with other objects without the operator having to input the data.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the probing method and apparatus of the present invention will be described below with reference to FIGS.

FIG. 1 is a schematic front view showing an embodiment of a probing apparatus of the present invention. In FIG. 1, 9 is a fixed table and 10 is an I for mounting an IC to be tested.
A board provided with a C socket 11, a so-called DUT
(Device under test) board.

Reference numeral 12 is an IC tester (LSI tester) for testing the IC mounted in the IC socket 11 via external pins of the IC.

FIG. 2 is a schematic front view showing an enlarged portion of the IC socket 11, and FIG. 3 is a schematic plan view of the portion of the IC socket 11 seen from above.

2 and 3, 14 is an IC to be tested. In this IC 14, 15 is a package, 16 is a window formed in the package 15, and 17 is an IC chip whose surface is exposed by the window 16. , 18 are external pins.

Further, in FIG. 1, 20 is the X direction and Y.
The XY stage 21 is movable in the direction, that is, the horizontal direction, and the Z stage 21 is fixed to the XY stage 20 and is movable in the Z direction, that is, the vertical direction.

Reference numeral 22 denotes a probe. The probe 22 detects a surface shape image (AFM image) for discriminating an arbitrary wiring on the IC chip 17 and the IC chip 17
It is used to detect an electrical signal on any wiring on the IC chip 17 for diagnosing the internal operation of the.

FIG. 4 is a schematic front view showing the tip portion of the probe 22. In FIG. 4, reference numeral 24 is a main body portion. In the main body portion 25, 25 is a hollow rod and 26 is a hollow body. Electro-optical crystal fixed to the tip of rod 25, 2
A magnet 7 is fixed to the electro-optic crystal 26.

Further, 28 is a needle, and in the needle 28, 29 is a head and 30 is a body part integrated with the head 29. As shown in FIG. 29 is attracted to the magnet 27 by the magnetic force of the magnet 27 so that it is integrated with the main body 24.

Further, the table 9 shown in FIG.
As shown in a schematic plan view and a schematic sectional view in FIG. 7, a needle storage portion 32 for storing a plurality of needles 28 is provided, and in these FIGS. 6 and 7, 33 is a hole portion. is there.

Here, the needle 28 is integrated with the main body portion 24 by moving the main body portion 24 above a predetermined needle 28 stored in the needle storage portion 32 and lowering the main body portion 24 to Two
This is performed by adsorbing the head portion 29 of No. 8 to the magnet 27 of the main body portion 24.

Further, in FIG. 1, 35 is an IC chip 1.
An optical microscope for observing the seven surfaces, and 36 is a probe 22.
It is a non-contact displacement sensor used to measure the area in which the can be moved.

As the non-contact displacement sensor 36, for example, a laser displacement meter for measuring displacement by triangulation or a laser displacement meter for measuring displacement by applying the principle of a confocal optical system is used. You can

FIG. 8 shows an example of a laser displacement meter for measuring displacement by triangulation. In FIG. 8, 38 is a case, 39 is a semiconductor laser which emits laser light, and 40 is a semiconductor laser 39. Laser light 41 is a projection lens for condensing the laser light 40 so that the laser light 39 becomes a spot of a predetermined size on the surface of the measurement object 42.

Further, 43 is an image forming lens for condensing the laser light 40 reflected by the measuring object 42 to form a spot image, and 44 is a position of the spot image formed by the image forming lens 43. It is a position sensor for detecting.

In this laser displacement meter, the spot image formed by the image forming lens 43 responds to the vertical movement of the surface of the measuring object 42, and the position sensor 4 accordingly.
4, the displacement of the surface of the measuring object 42 can be measured by extracting an electric signal corresponding to the spot image moving on the position sensor 44.

Further, FIG. 9 shows an example of a laser displacement meter for measuring the displacement by applying the principle of the confocal optical system. In FIG. 9, 46 is a semiconductor laser emitting laser light,
Reference numeral 47 denotes laser light emitted from the semiconductor laser 46, 4
Reference numerals 8 and 49 are half mirrors.

Numeral 50 is a collimator lens for collimating the laser light 47 into parallel light, and numeral 51 is the laser light 47 which is collimated.
Is an objective lens for forming a spot on the surface of the measuring object 52.

Further, 53 is a tuning fork for moving the objective lens 51 up and down, 54 is a tuning fork position detecting sensor for detecting the position of the tuning fork 53, and 55 is an objective lens position by amplifying the output of the tuning fork position detecting sensor 54. Is an amplifier that outputs an objective lens position signal indicating.

Reference numeral 56 is a CCD (charge coupled device) camera which reflects the laser beam 47 reflected by the surface of the object 52 to be measured, passes through the objective lens 51 and the collimator lens 50, and is reflected by the half mirror 49. is there.

Further, 57 is a pinhole which is reflected on the surface of the measuring object 52, passes through the objective lens 51, the collimating lens 50 and the half mirror 49, and controls the passage of the laser light 47 reflected by the half mirror 48, 58. Is a light receiving element that receives the laser beam 47 that has passed through the pinhole 57,
An amplifier 59 amplifies the output of the light receiving element 58 and outputs a light receiving signal.

In this laser displacement meter, the laser beam 47 emitted from the semiconductor laser 46 is the half mirror 4.
8, 49, the collimator lens 50, and the objective lens 51, and a small spot is formed on the surface of the measuring object 52.

The laser light 47 reflected on the surface of the object 52 to be measured is the objective lens 51 and the collimator lens 5.
0 and half mirror 49, and is reflected at a right angle by half mirror 48.

Here, when the laser light 47 reflected by the half mirror 48 is focused on one point at the position of the pinhole 57, it passes through the pinhole 57 and reaches the light receiving element 58, but of the pinhole 57. When the light is not focused at the position and is blurred, most of the laser light 47 cannot pass through the pinhole 57 and does not reach the light receiving element 58.

Therefore, in this laser displacement meter, the objective lens 51 is mechanically moved by the tuning fork 53, and when the objective lens 51 is in any position, the half mirror 48 is moved.
It is assumed that the distance to the measurement object 52 is measured by detecting whether the laser light 47 reflected by the light passes through the pinhole 57.

Here, when the internal operation diagnosis of the IC chip 17 is performed using the probing apparatus of this embodiment,
In advance, the positional relationship between the optical microscope 35 and the non-contact displacement sensor 36 is calibrated, and when focusing the optical microscope 35, first, the height of the observation position is measured by the non-contact displacement sensor 36, Then, the non-contact displacement sensor 36,
The optical microscope 35 is replaced and the height of the optical microscope 35 is adjusted.

In this case, I of various heights are used.
Even when the C chip is the test target, the focusing of the optical microscope 35 can be easily performed.

Next, the procedure shown in the flow chart of FIG. 10 is executed to measure the area where the probe 22 can be moved.

That is, first, as shown in FIG. 11 by showing the spot 61 of the laser beam outputted downward from the non-contact displacement sensor 36, the non-contact displacement sensor 36 is arranged at the end of the DUT board 10 in the X direction, and in the Y direction. The direction is located at the center of the DUT board 10 (step S1).

Next, the non-contact displacement sensor 36 is moved in the X direction while recording the height data which is its output (step S2). Note that FIG. 12 is a diagram showing how the non-contact displacement sensor 36 is moved in the X direction, and 63 is a laser beam output from the non-contact displacement sensor 36.

Then, it is judged whether or not the non-contact displacement sensor 36 has reached the opposite end of the DUT board 10 (step S3), and if it has not reached (NO in step S3).
In the case of), step S2 is continued.

After that, when the non-contact displacement sensor 36 reaches the end on the opposite side of the DUT board 10 (YES in step S3), the IC socket 11, the package 15 and the IC chip 17 are detected from the recorded height data. The position in the X direction is calculated (step S4). In FIG. 12, reference numeral 65 indicates height data to be recorded.

Next, referring to FIG. 13, the non-contact displacement sensor 36
The non-contact displacement sensor 36 is positioned at the center of the DUT board 10 in the X direction and at the end of the DUT board 10 in the Y direction so as to show the spot 61 of the laser beam output downward from (step S5).

Next, the non-contact displacement sensor 36 is moved in the Y direction while recording the height data which is its output (step S6).

Then, it is determined whether or not the non-contact displacement sensor 36 has reached the end on the opposite side of the DUT board 10 (step S7), and if it has not reached (NO in step S7).
In the case of), step S6 is continued.

After that, when the non-contact displacement sensor 36 reaches the end on the opposite side of the DUT board 10 (YES in step S7), the IC socket 11, the package 15 and the IC chip 17 are read from the recorded height data. The position in the Y direction is calculated (step S8). In FIG. 13, 67 indicates the height data to be recorded.

In the probing apparatus of this embodiment,
In this way, the IC socket 11, the package 15,
Since the positions of the IC chip 17 in the X direction and the Y direction can be obtained, it is possible to confirm the region where the probe 22 can be moved without colliding with the IC socket 11 or the package 15.

When diagnosing the internal operation of the IC chip 17, the optical microscope 35 is moved onto the IC chip 17 and the approximate position for positioning the probe 22 is confirmed, as shown in FIG.

Then, as shown in FIG.
2 is moved to the approximate positioning position confirmed by the optical microscope 35, the Z stage 21 is lowered, and scanning is performed while the probe 22 is in contact with the surface of the IC chip 17 at a constant interval.
A surface shape image (AFM image) of the chip 17 is obtained.

Then, the accurate positioning position is confirmed from the surface shape image, the probe 22 is accurately positioned and brought into contact with the wiring to be measured, the IC tester 12 drives the IC chip 17, and the probe 22 is used. An electric signal is detected and observed with an oscilloscope or the like. Thereby, the internal operation of the IC chip 17 can be diagnosed.

Here, in the probing apparatus of this embodiment, as described above, the non-contact displacement sensor 36 is used, and the IC socket 11, the package 15 and the IC are preliminarily used.
By obtaining the position of the chip 17 in the X direction and the Y direction, it is possible to automatically confirm the area where the probe 22 can be moved without colliding with the IC socket 11 or the package 15.

Therefore, according to the probing apparatus of the present embodiment, the probe 22 can measure the positions of the IC socket 11 and the package 15 by the operator and the operator does not input the data.
Do not collide with IC socket 1 of probe 22
It is possible to avoid damage due to collision with the package 1 or the package 15.

It should be noted that the non-contact displacement sensor 36 measures the positions of the heads 29 of the plurality of needles 28 stored in the needle storage section 32, and based on the position measurement results, the main body 2
4 is moved to the needle storage portion 32, and when the needle 28 of the probe 22 is replaced, the head portion 2 of the needle 28 is replaced.
9 can be attracted to the magnet 27 at an accurate position.

Further, when the vibration state of the IC chip 17 is detected by the non-contact displacement sensor 36 and an excessive vibration is detected, a warning is given and the probing can be stopped. It is possible to prevent the probe 22 from being damaged by the vibration of the IC chip 17 caused by the vibration of the IC tester 12 caused by the cooling fan.

Further, when not only the position of the IC chip 17 but also the in-plane rotation and inclination are measured by the non-contact displacement sensor 36, the positioning can be performed more easily.

[0058]

According to the probing method of the present invention, a region in which the probe can be moved is measured in advance using a non-contact displacement sensor, and the probing is performed by referring to the measurement result. Therefore, even if the operator measures the position of the object where the probe may collide and the operator does not input the data, the probe does not collide with other objects and the probe collides with other objects. You can avoid destruction by.

Further, according to the probing apparatus of the present invention, since the non-contact displacement sensor for measuring the region in which the probe can be moved is provided, the probe is preliminarily used by using this non-contact displacement sensor. By measuring the area that can be moved, the operator measures the position of the object where the probe may collide,
Even if the operator does not input the data, it is possible to prevent the probe from colliding with other objects and avoid the destruction of the probe due to the collision with other objects.

[Brief description of drawings]

FIG. 1 is a schematic front view showing an embodiment of a probing device of the present invention.

FIG. 2 is a schematic front view showing an enlarged portion of an IC socket included in an embodiment of the probing device of the present invention.

FIG. 3 is a schematic plan view of an IC socket included in an embodiment of the probing device of the present invention, as viewed from above.

FIG. 4 is a schematic front view showing a tip portion of a probe included in an embodiment of the probing device of the present invention.

FIG. 5 is a view for explaining the integration of the probe main body and the needle with which the probing device according to the embodiment of the present invention is provided.

FIG. 6 is a schematic plan view showing a needle storage portion provided on a table included in an embodiment of the probing device of the present invention.

FIG. 7 is a schematic cross-sectional view showing a needle storage unit provided on a table included in an embodiment of the probing device of the present invention.

FIG. 8 is a diagram showing an example of a laser displacement meter that measures displacement by triangulation.

FIG. 9 is a diagram showing an example of a laser displacement meter that measures displacement by applying the principle of a confocal optical system.

FIG. 10 is a flow chart showing a procedure for measuring a region where a probe can be moved in an example of the probing device of the present invention.

FIG. 11 is a diagram for explaining a procedure for measuring a region where a probe can be moved in an example of the probing device of the present invention.

FIG. 12 is a diagram showing the movement of a non-contact displacement sensor included in an example of the probing device of the present invention.

FIG. 13 is a diagram for explaining a procedure for measuring a region where a probe can be moved in an example of the probing device of the present invention.

FIG. 14 is a schematic front view showing a usage state of an optical microscope in an example of the probing device of the present invention.

FIG. 15 is a schematic front view showing a use state of a probe in one embodiment of the probing device of the present invention.

FIG. 16 is a perspective view showing an example of an integrated circuit in which a window for internal operation diagnosis is formed.

[Explanation of symbols]

 22 probe 35 optical microscope 36 non-contact displacement sensor

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hideki Sekiguchi 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa, within Fujitsu Limited (72) Inventor Akira Fujii 1015 Kamedota, Nakahara-ku, Kawasaki, Kanagawa within Fujitsu Limited ( 72) Inventor Yasutoshi Umehara 48-2 Matsubara Kami-Aiko, Aoba-ku, Sendai-shi, Miyagi Advantest Research Institute Co., Ltd.

Claims (7)

[Claims] 1. A surface shape of the surface of the integrated circuit chip for discriminating an arbitrary wiring on the integrated circuit chip, which is movable three-dimensionally, and electricity on an arbitrary wiring on the integrated circuit chip. In a probing device provided with a probe for performing signal detection, using a non-contact displacement sensor, in advance, measuring the region in which the probe can be moved, with reference to this measurement result, A probing method characterized by probing. 2. A surface shape of the integrated circuit chip surface for discriminating an arbitrary wiring on the integrated circuit chip, which is movable three-dimensionally, and electricity on an arbitrary wiring on the integrated circuit chip. A probe for detecting a signal and a non-contact displacement sensor for measuring a region in which the probe can be moved three-dimensionally are provided. Probing device. 3. The integrated circuit chip is an integrated circuit chip exposed through a window formed in a package, and the package is an integrated circuit tester for testing the integrated circuit chip via external pins. The probing device according to claim 2, wherein the probing device is attached to a socket for connection with the probing device. 4. An optical microscope for observing an arbitrary region on the integrated circuit chip, wherein the non-contact displacement sensor can be used to perform focusing of the optical microscope. Claim 2 or 3 characterized in that
The described probing device. 5. The non-contact displacement sensor measures the position, in-plane rotation and inclination of the integrated circuit chip to position the probe.
Or the probing device according to 4. 6. The probe comprises a needle storage portion for storing a plurality of needles at a position where the main body portion can be moved, the needle storage portion being formed by attracting the needles to the main body portion by magnetic force. The displacement sensor measures the positions of the plurality of needles stored in the needle storage unit, and based on the position measurement result, by moving the main body unit,
The probing device according to claim 2, 3, 4, or 5, wherein a needle can be attracted to the main body. 7. The probing device according to claim 2, wherein the non-contact displacement sensor detects the vibration state of the integrated circuit chip.