JPH05283489A - Wafer probing device - Google Patents

Abstract

PURPOSE:To prevent deviation of a pellet from probes from being generated by a method wherein when an alignment of the large-sized pellet to the probes is performed in a wafer testing process, the magnification of a stereomicroscope is increased to conduct operations. CONSTITUTION:A wafer probing device is provided with mirrors 3, 4, 5 end 6, which converge the images of bonding pads 1a and 2b provided respectively at two points separated from each other on a pellet 7 and lead the images to an objective lens of a stereomicroscope, and enlarges the images to conduct an alignment of the pads 1a and 1b provided respectively at the two points to probes 2a and 2b within the same visual field.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer probing apparatus, and more particularly to a wafer probing apparatus for testing electrical characteristics of pellets in a wafer test process.

[0002]

2. Description of the Related Art Conventionally, when aligning a probe of a probe card with a bonding pad on a pellet, one pellet is magnified and observed with a stereoscopic microscope, and all the probes come to the approximate center of the bonding pad. The position was adjusted by adjusting as follows.

At this time, in the case of a small pellet having a side length of about 2 to 5 mm, the bonding pad 21 and the probe 22 are sufficiently enlarged as shown in the microscope view of FIG. Positioning is possible.

However, in the case of a large-sized pellet having a side length of more than 10 mm, especially one-dimensional CCD
For pellets with one side exceeding 30 mm,
In order to put the entire pellet into the visual field, the magnification must be considerably reduced as shown in the microscope visual field view of FIG. 3, and the bonding pad 31 and the probe 32 are difficult to see.

[0005]

In this conventional wafer probing apparatus, since a stereoscopic microscope is used for alignment between the probe and the bonding pad of the pellet, it is necessary to work at a low magnification in the case of a large pellet. In addition, the probe and the pad were difficult to see, and there was a problem that accurate alignment could not be performed. If the alignment is not performed accurately, the probe will be misaligned, which will be a problem in terms of measurement yield and reliability.

[0006]

SUMMARY OF THE INVENTION A wafer probing apparatus of the present invention collects two bonding pad images separated from each other on a pellet and guides them to an objective lens, and a magnifying image for a stereoscopic microscope. The configuration is such that the two bonding pads and the probe are aligned within the same visual field.

[0007]

The present invention will be described below with reference to the drawings.

FIG. 1 (a) is a sectional view of an optical system according to an embodiment of the present invention, and FIG. 1 (b) is a microscope field view thereof. Figure 1
In the large-sized pellet 7 as shown in (a),
The image of the bonding pad 1a on one side is guided to the objective lens of the stereoscopic microscope by the mirror 3 and the mirror 4. The image of the bonding pad 1b on the opposite side is the mirror 5,
It is guided to the objective lens by the mirror 6. Bonding pads 1a, 1b, which are enlarged and observed in the visual field in FIG.
And the images of the probes 2a and 2b aligned with this are shown. If the positions of the mirror 3 and the mirror 5 are adjusted according to the bonding pads 1a and 1b, it is possible to accurately align a long and thin pellet having a pellet size of 1 mm × 30 mm like a one-dimensional CCD.

[0009]

As described above, according to the present invention, there are two
By providing a stereoscopic microscope having a function of guiding an image between points to an objective lens by a mirror, it is possible to accurately perform probe positioning of a large-sized pellet. In addition, since the probe position can be accurately adjusted, it is possible to eliminate the problems such as the decrease of the measurement yield and the problem of the total reliability due to the displacement of the probe, which has been a problem in the past.

[Brief description of drawings]

1A and 1B are views showing an embodiment of the present invention, in which FIG. 1A is a longitudinal sectional view and FIG. 1B is a microscope field view.

FIG. 2 is a microscope view of a conventional pellet having a small size.

FIG. 3 is a microscope view of a conventional pellet having a large size.

[Explanation of symbols]

 1a, 1b, 21, 31 Bonding pad 2a, 2b, 22, 32 Probe 3, 4, 5, 6 Mirror 7 Pellet

Claims (1)

[Claims] 1. A wafer probing apparatus for measuring the electrical characteristics of a pellet by aligning a probe with a bonding pad under a stereoscopic microscope to collect images of two bonding pads apart from each other on a pellet and guide them to an objective lens. Wafer probing device, characterized in that the image is magnified and the two bonding pads and the probe are aligned within the same field of view.