JP2817782B2 - Probe card inspection system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for inspecting a wafer of a semiconductor integrated circuit, and more particularly to a system for inspecting a probe card.

[0002]

2. Description of the Related Art Hitherto, there have been many proposals regarding probe cards used for inspecting wafers with an LSI tester, in terms of continuity and alignment between the probe cards and the wafer. No valid proposal has been made on the method.

In addition, due to the recent increase in the number of pins and the miniaturization of LSI chips, probe cards have also been miniaturized, making inspection very difficult.

[0004] Further, in order to shorten the development period, the importance of the preliminary check of the probe card is increasing.

In such a situation, there is no effective method for inspecting a probe card at present, and a continuity test using a hand tester, an LSI
There is a continuity test that is performed by attaching to a tester.

In a device in which a probe group of a probe card is brought into contact with an electrode of a semiconductor pellet, a signal is transmitted and received through the probe group, and an electrical characteristic of the semiconductor pellet is measured, the probe is arranged on a diagonal line of the semiconductor pellet. A needle displacement detection system in which a probe displacement detection needle made of a pair of wires that comes into contact with a provided conductor pad and conducts through the conductor pad is provided on a probe card is described in JP-A-63-246839. I have.

[0007]

According to such a conventional inspection method, for example, in a hand tester, a continuity test between a probe and an external connection terminal (a terminal for connecting to an LSI tester) is possible. However, due to the increase in the number of pins, the structure becomes finer, so that the number of inspection steps increases and the reliability of the inspection decreases. In addition, there is a disadvantage that it is not possible to check whether the position of the needle point is at a required coordinate position.

On the other hand, although the continuity test can be performed in a short time in the LSI tester, there is a disadvantage that the correspondence between the external connection terminal and the coordinate position of the probe tip and the incorrect connection between the probes cannot be inspected. Another problem is that a very expensive LSI tester is exclusively used for probe card inspection.

Accordingly, the present invention is directed to a probe card inspection system which improves the disadvantages of the prior art and can easily and easily reduce manufacturing defects such as incorrect connection and disconnection of a probe card and displacement of a probe in a short time. It is something to offer.

[0010]

SUMMARY OF THE INVENTION A probe card inspection system according to the present invention displays a voltage applied to an external terminal of a probe card via a probe of a probe card brought into contact with a first electrode surface of a display device. A device that supplies the device, an image conversion device that converts a change in the image of the display device caused by the voltage application into an electric signal, an image processing device that converts the electric signal obtained from the image conversion device into coordinate data, The display device has a determination device for comparing the image-processed data with the probe coordinates of the probe card, and a liquid crystal display is used as the display device, and the liquid crystal display has a first contact with the probe. Only a transparent electrode for reference coordinates is provided on the electrode surface, and a transparent electrode is provided on the entire surface of the opposing second electrode surface.

[0011]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram of one embodiment of the present invention, FIG. 2 is a partially enlarged perspective view of FIG. 1, and FIG. 3 is a diagram in which a voltage is applied to one external connection terminal. FIG. 4 shows a display state of the liquid crystal display when voltage is applied, and FIG. 4 shows a display state of the liquid crystal display when voltage is applied to all external connection terminals.

In FIGS. 1 to 4, 1 is a probe card, 2 is a liquid crystal display (hereinafter, referred to as LCD), 3 is a power supply for driving the LCD, and 4 is L.
C for storing the display state of the CD and converting it to an electric signal
An image conversion device (hereinafter referred to as a CCD) using a CD, an image processing circuit 5 for processing a signal from the CCD 4, and a determination circuit 6 for collating and determining with coordinate data of a probe.

As shown in FIG. 1, the external connection terminals 11 of the plurality of probe cards 1 are electrically connected to corresponding probes 12, respectively, and the probes 12 are connected to the LCD 2.

At this time, as shown in FIG.
It is in contact with the first electrode surface 21 of CD2.

On the other hand, the transparent electrode 24 provided on the entire surface of the second electrode surface 22 facing the first electrode surface 21 of the LCD 2
Is connected to one terminal of the power supply 3. In this state, when the other terminal of the power supply 3 is connected to one of the external terminals, a voltage is applied to the LCD 2 by the probe 12 and the transparent electrode 24. Will be done.

Since the power supply terminal is also connected to the reference coordinate transparent electrode 23 provided on the first electrode surface, the power supply terminal is provided immediately below the probe 12 and the reference coordinate transparent electrode 23. In the case, an electric field is generated in the vertical direction, and under the influence of the electric field, the liquid crystal in a portion immediately below is deflected. The deflection unit 25 in FIG.
This shows a state where the liquid crystal is deflected by the electric field.

In this state, for example, a case where a twisted nematic material is used as a liquid crystal material will be described.
The first and second electrode surfaces are provided with first and second deflection filters in orthogonal directions, respectively.

When light enters the LCD 2 from the top of the figure,
Since the liquid crystal in the portion where the electric field is not applied is arranged so as to be twisted at 90 ° above and below the LCD 2, the light passing through the first deflection filter is twisted 90 ° along the liquid crystal and the second orthogonal light is applied. The light is directed in the same direction as the deflection direction of the deflection filter and passes through the LCD 2.

On the other hand, the portion where the electric field is applied is affected by the electric field and the long axis of the liquid crystal is twisted in the vertical direction.
The light that has entered the CD 2 passes through without being deflected. Therefore, unlike the deflection direction of the second deflection filter, the light is
Cannot pass through LCD2.

FIG. 3 is a view showing the state of passage of light incident from the upper side of FIGS. 1 and 2 viewed from the lower side of the LCD 2. At this time, 26 indicates a probe position mark corresponding to the position of the probe to be inspected, and 27 indicates a reference mark indicating a reference coordinate position.

Next, the probe position mark 26 and the reference position mark 27 are captured by the CCD 4 and the image data is converted into position data. Probe position data is obtained from the relative position between the reference mark and the probe position.

Next, if this operation is repeated by the number of the external connection terminals 11, coordinate data or drawings of the probe positions corresponding to the external connection terminals 11 can be created by the image processing circuit 5. If the coordinate data or the drawing is compared with the probe coordinate data used when creating the probe card or the drawing showing the pads of the semiconductor chip by the determination circuit 6, the positional deviation and conduction between the external connection terminal and the pad position can be obtained. Testing becomes possible.

FIG. 4 shows a state displayed on the LCD 2 when a voltage is applied to all the probes. The probe position mark 26 at this time indicates the pad position of the semiconductor chip.

In the above-described present invention, DC power is applied. However, in order to extend the life of the LCD, a method of inverting the voltage applied to the LCD is generally used.

Although the switching of the external connection terminals is not particularly described, it goes without saying that the inspection can be executed in a shorter time by using a jig or the like that switches mechanically or electrically.

[0027]

As described above, according to the present invention, by applying a voltage to the display device through the probe of the probe card, a probe card such as an erroneous connection, a non-connection, and a probe position shift can be obtained. It is possible to easily and easily test items required for the test in a short time.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an outline of an embodiment of the present invention.

FIG. 2 is an enlarged perspective sectional view of a part of FIG.

FIG. 3 is a perspective view showing a display state of the LCD when a voltage is applied to some of the probes in one embodiment of the present invention.

FIG. 4 is a perspective view showing a display state of the LCD when a voltage is applied to all the probes in the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Probe card 2 Liquid crystal display (LCD) 3 Power supply 4 Image conversion device (CCD) 5 Image processing circuit 6 Judgment circuit 11 External connection terminal 12 Probe 21 First electrode surface 22 Second electrode surface 23 Transparent electrode for reference coordinates 24 Transparent electrode 25 Deflector 26 Probe position mark 27 Reference mark

Claims (3)

(57) [Claims] 1. A device for supplying a voltage applied to an external terminal of a probe card to a display device via a probe of a probe card in contact with a first electrode surface of the display device, and a display generated by applying the voltage. An image conversion device that converts an image of the device into an electric signal, an image processing device that converts an electric signal obtained from the image conversion device into coordinate data, and a determination that the image-processed data is compared with the probe coordinates of a probe card Probe card inspection system consisting of devices. 2. The probe card inspection system according to claim 1, wherein the display device comprises a liquid crystal display. 3. A liquid crystal display in which only a transparent electrode for reference coordinates is provided on a first electrode surface in contact with a probe, and a transparent electrode is provided on an entire surface of a second electrode surface facing the probe. The probe card inspection system according to claim 2.