JP2003088966A - Laser marking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser marking device that reduces marking time and that enables throughput to be improved. SOLUTION: A laser beam 7 outputted from a laser oscillator 1, with the beam diameter expanded by a beam expander 2, passes through a slit 100 and, with the optical path bent by a folding mirror 3, is deflected by a galvano- mirror 4. Then, the laser beam is converged by an fθ lens 5, while an area to be irradiated by the laser beam 7 is formed on the surface to be worked of a marking object 6, marking is performed. The slit 100 is rectangular in the light passing part, the size is made variable. The surface to be worked of the marking object 6 is arranged at the position where the rectangular pattern of the slit 100 is image-formed. This structure enables one rectangular cell of a two-dimensional data code to be constituted of one dot 102.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser marking apparatus suitable for marking a semiconductor substrate or a liquid crystal substrate with categorizing symbols, codes or the like.

[0002]

2. Description of the Related Art A laser marking device irradiates a laser beam to perform marking. Conventionally, a laser marking device has been used to print characters and symbols for classification on a semiconductor substrate, a liquid crystal substrate, or the like. In recent years, two-dimensional codes are often used in place of characters in fields such as quality control and physical distribution. The two-dimensional code is a two-dimensional pattern having information, and information such as lot number and product number is embedded in this pattern to manage individual products. The two-dimensional code includes, for example, a data code,
There are Veri code, QR code, etc.

[0003]

FIG. 4 shows a configuration diagram of a conventional scanning type laser marking device. In the device shown in FIG. 4, the laser beam 7 output from the laser oscillator 1 has its beam diameter expanded by the beam expander 2, then the optical path thereof is bent by the bending mirror 3, and the two galvano mirrors 4 two-dimensionally. Biased to. Then, the light is focused by the fθ lens 5 and is applied to the marking object 6 which is a workpiece. Laser light 7 is applied to the surface of the marking object 6 to be processed.
An irradiation area is formed by this, and marking is performed by this.

FIG. 5 shows one example of marking by scanning the laser beam two-dimensionally in this way. FIG. 5A is a part of the two-dimensional data code created by marking. FIG. 5 (b) is a partially enlarged view of FIG. 5 (a). The cross section of the irradiated laser beam is usually circular. Therefore, the dot 8 which is the irradiation area on the surface to be processed is also circular. Conventionally, as shown in FIG. 5B, a basic unit cell 9 forming a two-dimensional code is formed of a plurality of dots 8. In the case of FIG. 5B, a total of 12 dots 8 which are 4 vertically and 3 horizontally constitute one cell 9.

The size of the cell 9 differs depending on the type of two-dimensional code and the object to be processed. The size of the dot 8 is determined by the diameter of the beam with which the marking target 6 is irradiated. This beam diameter cannot be changed unless the magnification of the beam expander 2 or the fθ lens 5 is changed. Changing these parts requires setting and alignment and is not easy. Therefore, conventionally, when it is desired to change the size of the cell 9, the number of dots 8 constituting the cell 9 is changed and marking is performed.

In the method described above, a large number of dots 8 must be irradiated to mark one cell 9. Therefore, there is a problem that it takes time to mark one cell and the throughput is lowered.

The present invention has been made in view of the above problems, and an object thereof is to provide a laser marking apparatus capable of shortening the marking time and improving the throughput. .

[0008]

In order to solve the above-mentioned problems, a first invention of the present invention is a laser marking device for irradiating and marking a laser beam while scanning a surface to be processed, which comprises: A slit for converting the cross-sectional shape of the laser beam into a desired shape and / or a desired size is provided in the optical path between the scanning optical system and
Provided is a laser marking device, wherein the slit and the surface to be processed are arranged at optically conjugate positions.

According to this structure, since the image of the slit is formed on the surface to be processed, the irradiation area corresponding to the shape and size of the opening of the slit is formed on the surface to be processed. A desired irradiation area can be obtained only by providing a slit corresponding to the size of the cell of the two-dimensional code to be marked in consideration of the magnification of the optical system.

At this time, the size of the opening of the slit is variable, and it is preferable to further include control means for controlling the size of the opening. According to this configuration,
Even if the size of the cell changes, the size of the opening can be changed flexibly by changing the size of the opening.

Further, the opening portion of the slit can have any shape. For example, it may be configured to have a star shape or a rectangular shape. In the past, since the cross-sectional shape of the laser beam was usually circular, the irradiation area was also circular. However, if the shape of the cell is rectangular, a sharper marking can be formed if the irradiation area is also rectangular.

In the above apparatus, an optical fiber for guiding the laser light from the laser light source into an optical path between the laser light source and the slit, and an incident optical system for guiding the laser light to the optical fiber. And a collimating optical system that collimates the light emitted from the optical fiber.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. In addition, in the following description and the accompanying drawings, components having substantially the same function and configuration are denoted by the same reference numerals, and redundant description will be omitted. FIG. 1 is a schematic configuration diagram of a laser marking device according to a first embodiment of the present invention, which is greatly different from the device of FIG. 4 in that a slit 100 is provided. The schematic configuration of the present apparatus will be described with reference to FIG.

A laser beam 7 output from a laser oscillator 1 which is a laser light source has a beam diameter expanded by a beam expander 2 and then a slit 10 having a rectangular opening.
Pass 0. For example, a continuous pumped Q-switched Nd: YAG laser is used as the laser oscillator, and the output beam (beam diameter 2φ) is doubled with a beam expander 2 of 4φ.
Expand to. It is cut out with a 1 mm square slit 100. After that, the laser light 7 is bent in its optical path by the bending mirror 3 and is two-dimensionally deflected by the two galvano mirrors 4. Then, the fθ lens 5 having a focal length of 100 mm placed at a position 1000 mm from the slit 100 collects the light and irradiates the marking target 6 which is a workpiece. An irradiation area of 0.1 mm square is formed by the laser beam 7 on the surface to be processed of the marking object 6, and marking is performed by this.

Here, the slit 100 and the surface to be processed of the marking object 6 are arranged at optically conjugate positions. That is, the surface to be processed of the marking object 6 is arranged at the position where the rectangular pattern of the slit 100 is imaged.

The slit 100 has a rectangular opening through which light can pass, and the opening 100 has a function of converting the cross-sectional shape and size of the laser beam into a desired shape. The expansion magnification of the beam expander 2 can be set so that the beam diameter of the laser light 7 that has passed through the beam expander 2 sufficiently fills the opening. The size of the opening is configured in consideration of the magnification of the optical system such as the fθ lens 5 so that the irradiation area has the same size as the cell size of the code or the like to be marked.

The size of the opening of the slit 100 is variable. For example, as the slit 100, a plurality of slits having different sizes which can be freely inserted into and removed from the optical path are prepared, and can be replaced by the control means. Alternatively, the width of the rectangle in two directions can be continuously changed by the electric control means.

With the above structure, the cross-sectional shape of the laser beam after passing through the slit 100 becomes a rectangle corresponding to the opening of the slit 100. Further, the size of the irradiation area on the surface to be processed of the marking object 6 is the same as the cell size of the code. FIG. 2 shows an example in which laser light is two-dimensionally scanned and marked by the above device. FIG. 2 is a partially enlarged view of what is marked with a two-dimensional data code similar to that shown in FIG. As can be seen from FIG. 2, here, the dot 102 has a rectangular shape, and one dot constitutes one cell. The dot 102 has the same size as the cell 9 shown in FIG.

Conventionally, one cell is composed of a plurality of dots, but according to the present embodiment, one dot constitutes one cell. Therefore, compared to conventional
The time required for marking is significantly reduced. Therefore, the processing time for one product is shortened and the throughput is improved. The time for printing the code shown in FIG. 5A was 6.2 seconds in the conventional method, but according to the application example of the present invention, 1.
It's been 6 seconds. In addition, since the dots are also rectangular according to the rectangular cells, clearer markings can be formed. Further, since the slit size can be changed by the control means, it is possible to deal with a change in cell size depending on the type of the two-dimensional code or the processing target.

As a modification, the device configuration shown in FIG. 3 is also possible. In the apparatus of FIG. 3, the beam expander 2
Instead of the optical fiber 104, an optical fiber 104, an incident lens 105, and a collimator lens 106 are arranged. Laser oscillator 1
The laser light 7 output from the laser beam is condensed by the incident lens 105 and is incident on the optical fiber 104 for guiding light. The laser light 7 emitted from the optical fiber 104 is reflected by the collimator lens 1
The collimated beam is collimated by 06, and the slit 10
Pass 0. After that, the laser light 7 is emitted from the folding mirror 3
The optical path is bent by and is two-dimensionally deflected by the two galvanometer mirrors 4. Then, the light is focused by the fθ lens 5 and is applied to the marking object 6 which is a workpiece. An irradiation area is formed by the laser beam 7 on the surface to be processed of the marking object 6, and marking is performed by this.

In this modification, the configuration and arrangement of the slit 100 are the same as in the above example. Also in this modification,
The same irradiation area as in the above example is obtained, and the same effect as in the above example is obtained. Furthermore, by using an optical fiber, the degree of freedom in arranging optical components increases.

The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such examples. It is obvious to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims, and of course, the technical scope of the present invention is also applicable to them. Be understood to belong to.

[0023]

As described above in detail, according to the present invention, it is possible to provide a laser marking device capable of shortening the marking time and improving the throughput.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a laser marking device according to an embodiment of the present invention.

FIG. 2 is an example of marking by a laser marking device according to an embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a laser marking device of a modified example of the invention.

FIG. 4 is a schematic configuration diagram of a conventional laser marking device.

FIG. 5 is an example of marking by a conventional laser marking device.

[Explanation of symbols]

1 Laser oscillator 2 beam expander 3 folding mirror 4 galvo mirror 5 fθ lens 6 Marking object 7 laser beam 8 dots 9 cells 100 slits 102 dots 104 optical fiber 105 Incident lens 106 Collimating lens

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Claims (4)

[Claims] 1. A laser marking device for irradiating and marking a surface to be processed with a laser beam while scanning the surface, wherein the laser beam has a desired cross-sectional shape in the optical path between the laser light source and the scanning optical system. And / or a slit for converting to a desired size is provided, and the slit and the surface to be processed are arranged at positions optically conjugate with each other. 2. The laser marking device according to claim 1, wherein the size of the opening of the slit is variable, and further comprising control means for controlling the size of the opening. 3. The laser marking device according to claim 1, wherein the opening of the slit has a rectangular shape. 4. An optical fiber for guiding the laser light from the laser light source and an optical fiber for guiding the laser light emitted from the laser light source to the optical fiber in an optical path between the laser light source and the slit. 4. An incident optical system, and a collimating optical system for collimating the light emitted from the optical fiber, according to any one of claims 1 to 3.
The laser marking device according to the item.