JP2723662B2 - Automatic character recognition device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic character recognition apparatus, and more particularly, to an automatic character recognition apparatus for automatically recognizing a character imprinted on a semiconductor wafer.

[Prior Art] FIG. 3 is a schematic diagram of an automatic character recognition apparatus showing an example of the related art. Conventionally, this type of automatic character recognition device has
As shown in the figure, a light source unit 4 that generates parallel light guided by an objective lens, an image pickup device 3 that images a character 5 enlarged by the objective lens unit 4, and a signal from the image pickup device 3 It comprises a monitor TV2 for displaying characters and an automatic recognition unit 1 for recognizing the characters based on signals from the image pickup device 3. Conventionally, using such an automatic character recognition device, a character that has been engraved or printed on a wafer is recognized, and whether or not the character is engraved or printed and whether or not the character is a reference character are inspected. Was.

[Problems to be solved by the invention]

In the above-described conventional automatic character recognition device, when a character is imprinted with a certain contrast on a smooth semiconductor wafer, the character can be automatically recognized accurately, but is imprinted on an LSI pattern. In some cases, in particular, if the character is not deeply carved, the light reflected from the surface is strong, halation occurs, and if the contrast cannot be obtained, there is a disadvantage that automatic recognition may not be performed.

An object of the present invention is to provide an automatic character recognizing device that overcomes such disadvantages.

[Means for solving the problem]

The automatic recognition of characters according to the present invention includes an image pickup device that images characters imprinted on a semiconductor wafer from directly above via an objective lens, a light source unit that irradiates a character region, and a light source unit that holds the light source unit and A first rail for adjusting an angle between the first rail and an optical axis of the lens; a first rail surrounding the semiconductor wafer;
And a second rail for rotating and sliding the rail.

〔Example〕

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

FIG. 1 is a schematic view of an automatic character recognition apparatus showing one embodiment of the present invention. As shown in FIG. 1, the automatic character recognition device includes a light source unit 6 for illuminating the character 5 with light obliquely, a rail 7 for adjusting the irradiation monitor angle of the light source unit 6, and And a rail 8 that moves in a circle around the center. This makes it possible to soften the intensity of the reflected light from the character 5,
Moreover, the contrast can be easily obtained even with a lightly carved character.

For example, in the case where a character with a small carving is engraved on the LSI pattern on the wafer 10, that is, when the contrast of the character is hard to be obtained, first, the light source unit 6 is moved along the guide rails 7, 8, and the LSI pattern The position and the angle are adjusted while watching the monitor TV2 so that the signal from the character 5 is the smallest and the contrast of the character is maximized. Subsequently, the characters are taken into the image pickup device 3 and are automatically recognized.

FIG. 2 is a schematic view of an automatic character recognition apparatus showing another embodiment of the present invention. As shown in the drawing, this automatic character recognition device is provided with a dimmer 9 for adjusting the brightness of the light source of the light source unit 6 in addition to the above-described embodiment.
Other than that, it is the same as the above-mentioned embodiment. By adjusting the intensity of the light source illuminated by the dimmer 9, the automatic character recognition device makes it easier to obtain a difference in the intensity of the reflected light from the character 5, and can easily obtain contrast even in a character with a small engraving. Can be done.

〔The invention's effect〕

As described above, the present invention provides a means for adjusting the irradiation angle and intensity of a light source for illuminating a character formed by a shallow, glossy base material on a semiconductor wafer, thereby reflecting more than necessary. . Reduce the reflected light intensity,
The automatic character recognition device can easily maintain the contrast of the characters and can reliably recognize even the lightly carved characters.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an automatic recognition device showing one embodiment of the present invention, FIG. 2 is a schematic diagram of an automatic character recognition device showing another embodiment of the present invention, and FIG. It is a schematic diagram of the recognition device of the character shown. DESCRIPTION OF SYMBOLS 1 ... Automatic recognition part, 2 ... Monitor TV, 3 ... Image pickup device, 4 ... Objective lens unit, 5 ... Character, 6 ... Light source unit, 7.8
... guide rails, 9 ... dimmers.

Claims (1)

(57) [Claims] 1. An image pickup device for picking up an image of a character imprinted on a semiconductor wafer from directly above via an objective lens, a light source unit for irradiating the character area, and a light source unit for holding the light source unit and the objective lens. A first rail for adjusting an angle formed with the optical axis; and a second rail provided surrounding the semiconductor wafer and connecting one end of the first rail and rotating and sliding the first rail. An automatic character recognition device, comprising: