JP2003130620A - Apparatus for testing shape of object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems wherein in methods for testing the shape of an object, e.g. the shape of a bump, using conventional techniques, the light cutting method, the laser scanning method and the three-dimensional testing method using conformal points can not test the shape of bump because of placing emphasis on testing the height of bump, or the test method carrying out image processing using a video camera can not test the presence or absence of an abnormal projection on the bump other than the position and size of the bump because of lighting and photographing means. SOLUTION: The apparatus for testing the shape of object, which has an illuminating means that obliquely illuminates the object under test for testing the shape, and which has a photographing means that obliquely photographs the object under test illuminated by the illuminating means in the reverse direction relative to the illumination and outputs picture signals, determines whether the shape of the object under test is good or not using data obtained by digitizing the picture signal inputted from the photographing means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optimum object for inspecting the shape of an object, for example, the shape of a bump formed on a silicon wafer, which is a base material when manufacturing an LSI which is a semiconductor device. The present invention relates to a shape inspection device.

[0002]

2. Description of the Related Art Generally, as conventional techniques for inspecting the shape of bumps, there are three-dimensional inspection using confocal, inspection using optical cutting method, and inspection using laser scanning method. Further, as a simple method for inspecting the shape of the bump, there is a method of performing an image processing of an image signal from above the bump by using an illumination device directly above and a video camera directly above to perform the inspection.

[0003]

As described above, various methods have been developed for the method of inspecting the shape of an object, for example, the bump shape according to the prior art, and each method has the following features. There is a problem. The three-dimensional inspection using the confocal point, the optical cutting method, and the laser scanning method focus on the bump height inspection, and therefore cannot perform the bump shape inspection.

Further, the inspection method by image processing using a video camera has a problem in that it is impossible to inspect the presence or absence of an abnormal protrusion on the bump other than the position and size of the bump depending on the illumination and imaging methods. It is an object of the present invention to solve these problems and inspect the shape of an object and the presence or absence of an abnormal protrusion on a bump, for example.

[0005]

In order to solve the above problems, an object shape inspection apparatus of the present invention has a moving stage, moves an object to be inspected, and obtains an image signal of the object to be inspected obliquely. In an apparatus for inspecting the shape of the object to be inspected by performing image processing on the object to be inspected, the illumination means obliquely illuminating the object to be inspected whose shape is to be inspected, and the object to be inspected illuminated by the illuminating means. An image pickup means for picking up an image in an oblique direction opposite to the above and outputting a video signal, and data for digitizing the video signal inputted from the image pickup means are used to judge the quality of the shape of the inspected object. Is.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The form of an object shape inspection apparatus according to the present invention will be described by way of examples. 1 is an embodiment of an object shape inspection apparatus according to the present invention, FIG. 2 is a conceptual diagram of an inspection of a protrusion generated on a bump, and FIG. 3 is a diagram showing the protrusion generated on the bump obtained by the inspection. An example of an image in the case is shown. In FIG. 1, 1 is an oblique illumination head, 2 is an illumination light source and power source, 3 is an oblique video camera, 4 is an imaging lens, 5 is an image processing device, 7 is a video monitor device, 8 is a computer,
9 is a Z-direction moving stage, 10 is a θ rotation stage, 11
Is an XY movement stage, 12 is a stage driver, 1
3 is an object to be inspected. In FIG. 2, 20 is an oblique video camera, 21 is an imaging lens, 22 is an oblique illumination head,
Reference numeral 23 is a protrusion on the bump, and 24 is a bump. In FIG. 3, 30 is a bump image, 31 is a protrusion on the bump, and 32 is the shadow of the protrusion. A supplement of each component in FIG. 1 will be described below. Reference numeral 13 denotes an inspected object whose shape is to be inspected, 10 denotes a θ rotary stage capable of performing alignment correction of the mounted inspected object 13 in the rotational direction, and 11 denotes the mounted inspected object 13 in the X-axis direction and the Y-axis. XY movement stage that can be moved in any direction, 3 is an oblique video camera, 4 is an image pickup lens that takes in the optical image of the object 13 to be inspected into the oblique video camera 3, and 9 is the oblique video camera 3 and oblique illumination. The Z-direction moving stage 5 capable of moving the head 1 in the Z-axis direction performs image processing of the video signal input from the oblique video camera 3, stores the image signal, and stores the stored image data in the computer 8 and the video monitor device 7. Image processing device for outputting to a device, 2 is a light source and a lighting power supply device, 8 is an inspection process based on image data input from the image processing device 5, and the inspection result is a CRT, a printer, or the like. And outputs, computer controlling the inspection apparatus in general, 12 XY direction moving stage 1 is controlled from the computer 8
1, a stage driver that controls and drives the movements of the θ rotation stage 10 and the Z-direction moving stage 9, and 7 is an image processing apparatus 5.
It is a video monitor device that displays an image input from the device. The operation when inspecting the object shape will be described. First, the inspected object 13 whose shape is to be inspected is placed on the θ rotary stage 10 attached to the XY direction moving stage 11. Next, the XY-direction moving stage 11 and the Z-direction moving stage 9 are moved, and the bumps of the object 13 to be inspected are covered by the imaging system including the oblique illumination head 1, the imaging lens 4, and the oblique video camera 3. The X-axis, Y-axis, and Z-axis are positioned so that they can be individually imaged.
At this time, the light source of the imaging lens 4 and the optical axis of the oblique illumination head 1 are set to coincide with each other on the inspected object 13, for example, on the bump mounting surface. Next, the XY-direction moving stage 11 is moved in accordance with the inspection coordinate information registered in the computer 8 in advance, the bumps of the mounted inspection object 13 are imaged, and sequentially captured in the image processing device 5. In the conceptual diagram of the inspection of the protrusions generated on the bumps shown in FIG.
The projection 23 generated on the bump 24 is replaced by the oblique lighting head 2
2 is irradiated with light, and the bumps 24 and the protrusions 2 are formed by the oblique video camera 20 and the imaging lens 21 which are arranged in the opposite oblique direction.
A video signal obtained by capturing image 3 is captured by the image processing device 5 in FIG. An example of this captured image is shown in FIG. In the bump captured image 30 of FIG. 3, the image of the projection 31 on the bump becomes bright, whereas the shadow 32 of the projection becomes dark.
A portion of the shadow 32 of the darkening projection is detected, and a determination process is performed to determine that a bump in which the darkening portion of the image exceeds a preset range is defective.

[0007]

According to the present invention, defects such as protrusions generated on bumps can be detected by using an oblique illumination and an oblique video camera which is the reverse of the illumination.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an example of an object shape inspection apparatus according to the present invention.

FIG. 2 is a conceptual diagram of inspection of a protrusion generated on a bump according to the present invention.

FIG. 3 is an example of a captured image of a protrusion generated on a bump according to the present invention.

[Explanation of symbols]

1: Oblique illumination head, 2: Illumination light source and power supply, 3: Oblique video camera, 4: Imaging lens, 5: Image processing device,
7: Video monitor device, 8: Computer, 9: Z direction moving stage, 10: θ rotation stage, 11: XY direction moving stage, 12: Stage driver, 13: Inspected object, 20: Oblique video camera, 21: Imaging Lens, 2
2: Oblique illumination head, 23: Protrusion on bump, 2
4. Bump, 30: Bump image, 31: Protrusion on bump, 32: Shadow of protrusion

Claims (2)

[Claims] 1. An apparatus for inspecting a shape of an object to be inspected by moving an object to be inspected and image-processing a video signal of the object to be inspected, which comprises a moving stage, As a means for illuminating a certain object to be inspected, an illumination means in which the irradiation angle with respect to the inspection object is obliquely arranged, and the object to be inspected illuminated by the illuminating means is imaged obliquely in the opposite direction to the illumination, An object shape inspection apparatus comprising an image pickup means for outputting a video signal and data for digitizing the video signal inputted from the image pickup means, and having a shape quality judgment means for the shape of an object to be inspected. 2. A video signal obtained by obliquely picking up a bump on the wafer is image-processed while moving (without stopping) a wafer having a moving stage and having bumps (projection electrodes). In an object shape inspection device for inspecting the shape of a bump, as a means for illuminating the bump whose shape is to be inspected, an illuminating device having a light source whose illumination angle with respect to the bump is arranged obliquely, and illumination by the illuminating device A video camera (for example, a high-speed shutter TV camera, a line TV camera, etc.) that outputs an image signal of the bumped image picked up from the opposite direction of the illumination and digitizes the image signal input from the video camera. An object shape inspection apparatus characterized by having a quality determination unit for the shape of a bump using the obtained data.