JPH053230A - Wafer prober - Google Patents

Abstract

PURPOSE:To control a change by time in needle pressure of a prober and displacement of the needle by providing a pickup device for a prober contact trace, a memory device for a picture image signal from a pickup device, a picture image reproduction control part for a signal from the memory device, and a display device for a reproduced picture image, and inspecting a history of the change by time in the prober contact trace. CONSTITUTION:A pickup part 2 picks up a semiconductor chip image on a wafer and outputs an image signal V which signal is then inputted to an image processing control part 3. The image processing control part 3 converts the image signal V to a display image signal VD with the aid of a prober control part 4 and feeds it to a display 8 for display off the same. The image processing control part 3 stores the image signal V in a memory part 5 as image data DD with the aid of the control signal CV. Upon the stored image data being reproduced for example reproduced image data DR is read out from the memory part 5 through the control of a prober control part 4 and is converted to a reproduction display image signal VD, and is displayed on a display 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer prober, and more particularly to a wafer prober having a function of recording a probe contact mark on an electrode pad.

[0002]

2. Description of the Related Art A conventional wafer prober has a function of recording a probe contact mark generated when a probe comes into contact with an electrode pad when testing the electrical characteristics of a semiconductor chip formed on a semiconductor wafer. I didn't.

Conventionally, the detection and recognition of the probe contact mark on the electrode pad of the semiconductor chip is performed by taking out the wafer to be tested and observing the probe contact mark with a microscope after the test by the wafer prober is completed. This was done by photographing the contact marks and inspecting this photograph.

As a method of directly observing the probe contact trace on the electrode of the semiconductor chip on the wafer prober, a wafer mounted on the stage of the wafer prober is imaged by a television camera and the image is monitored. There was a method of displaying on the display.

[0005]

Since the above-mentioned conventional wafer prober does not have a recording function, there is a change in the probe contact trace over time due to the probe pressure or needle displacement in the same probe card. There was a drawback that it was impossible to check the history. Further, the method of recording the contact trace of the probe by photographing has a drawback that the wafer under test needs to be taken out each time photographing is complicated.

[0006]

A wafer prober of the present invention has a probe that contacts an electrode pad of a semiconductor chip formed on a semiconductor wafer, and the electrical characteristics of the semiconductor chip are measured through the probe. In the wafer prober to be tested, an imaging device that images a probe contact mark generated by contact of the probe on the electrode pad, a storage device that stores an image signal output from the imaging device, and the storage device. An image reproduction control unit that reproduces the read image signal and a display device that displays the reproduced image are configured.

[0007]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of the wafer prober of the present invention.

As shown in FIG. 1, the wafer prober of this embodiment includes a prober unit 1, an image pickup unit 2, an image processing control unit 3, a prober control unit 4, a storage unit 5, and an image reproduction control unit. 6, a display control unit 7, and a display 8.

The prober unit 1 is a main body of a wafer prober, and includes a stage on which a wafer under test is placed and a probe card in which probes are arranged so as to match the electrode arrangement of the semiconductor chip under test.

The image pickup section 2 picks up an image of the wafer placed on the stage of the prober section 1, and as an example, C
It is composed of an image sensor using a CD imaging device.
The image sensor may be either a video camera using a two-dimensional CCD area sensor or a line scanner using a one-dimensional CCD line sensor that also uses an appropriate scanning method.

The image processing control section 3 digitizes the image signal V output from the image pickup section 2 and transfers it to the storage section 5 as image data DD, and at the same time, displays an image for display from the image signal V on the display 8. Generate the signal VD.

The prober control unit 4 controls the prober unit 1 and also controls the image processing control unit 2 and the image reproduction control unit 6.

The storage unit 5 stores the image data DD from the image processing unit 3.

The image reproduction control unit 6 generates a display image signal VD for displaying on the display 8 from the reproduction image data DR read from the storage unit under the control of the prober control unit 4.

The display controller 7 controls the display on the display 8.

The display 8 is a normal CRT display.

Next, the operation of this embodiment will be described.

First, the image pickup section 2 picks up an image of the semiconductor chip to be imaged on the wafer mounted on the stage of the prober section 1. The image signal V output from the image pickup unit 2 is input to the image processing control unit 3. The image processing control unit 3 converts the image signal V into a display image signal VD suitable for the display 8 by the control signal CV of the prober control unit 4 and sends it to the display 8. The display 8 displays the display image signal VD as an image under the control of the display controller 7. Further, the image processing control unit 3 digitizes the image signal V output from the image pickup unit 2 by the control signal CV, and sends it to the storage unit 5 as image data DD. The storage unit 5 stores the transferred image data DD.

Next, when reproducing the stored image data, the prober control unit 4 sends an image reproduction command CR to the image processing control unit 3 and the image reproduction control unit 6. The image processing control unit 3 reads the image data from the storage unit 5 as reproduced image data DR and outputs it. Image reproduction control unit 6
Processes the reproduced image data DR and returns it to the image processing control unit 3 as a reproduced display image signal VDR, where it is converted into a display image signal VD and sent to the display 8 for image display.

Next, a second embodiment of the present invention will be described.

FIG. 2 is a block diagram showing a second embodiment of the wafer prober of the present invention.

The difference between this embodiment and the first embodiment shown in FIG. 2 is that an external storage device 9 is added.

The external storage device 9 transfers the image data DD from the storage unit 5 according to the image data storage command CS from the prober control unit 4 and stores it in a storage medium such as a floppy desk. In this case, the storage unit 5 stores the image data DD and the reproduced image data DR in the external storage device 9.
Will play the role of a buffer for temporarily storing.

In the present embodiment, by providing the external storage device 9, there is an advantage that a large amount of image data can be recorded as a history of changes in probe contact traces over time.

Further, since the recording medium FD can be reproduced and displayed by another independent image reproducing and displaying apparatus 10,
It is effective for the management and maintenance of the wafer prober.

[0027]

As described above, the wafer prober of the present invention is provided with an image pickup device of a probe contact mark, a storage device of an image signal from the image pickup device, an image reproduction control section from the storage device, and a reproduced image. With this display device, it is possible to record and reproduce the probe contact mark of the semiconductor chip of the wafer under test at any time, so check the history of change over time of the probe contact mark on a specific probe card. By doing so, there is an effect that it is possible to manage changes over time such as needle pressure of the probe and needle displacement. Further, since it is not necessary to take out the wafer to be tested each time the probe contact trace is observed and recorded, there is an effect that the management and maintenance of the wafer prober can be efficiently performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a wafer prober of the present invention.

FIG. 2 is a block diagram showing a second embodiment of the wafer prober of the present invention.

[Explanation of symbols]

1 prober section 2 Imaging unit 3 Image processing controller 4 Prober control section 5 memory 6 Image playback controller 7 Display control section 8 display 9 External storage device 10 Image reproduction display device

Claims (3)

[Claims] 1. A wafer prober having a probe contacting with an electrode pad of a semiconductor chip formed on a semiconductor wafer, and testing electrical characteristics of the semiconductor chip through the probe, the prober is provided on the electrode pad. An image pickup device for picking up an image of a probe contact mark generated by the contact of the probe, and a storage device for storing an image signal output from the image pickup device,
A wafer prober comprising: an image reproduction control unit for reproducing the image signal read from the storage device; and a display device for displaying the reproduced image. 2. The wafer prober according to claim 1, wherein the image pickup device is an image sensor including a CCD image pickup device. 3. The storage device includes an image processing circuit for converting the image signal output from the imaging device into digital image data, an internal storage circuit for temporarily storing the digital image data, and a storage in the internal storage circuit. The wafer prober according to claim 1, further comprising: an external storage device that stores the digital image data in an external storage medium according to a predetermined command.