JP2000301367A - Laser marking method and work marked by the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent a substrate from peeling off by preventing the substrate from being made in direct contact with a laser beam. SOLUTION: When marking characters, graphics, etc., by scraping the range wider than a beam spot of a laser beam on the surface of a work 1 in which two surface treated layers of a substrate 3 and a surface layer 4, by scanning the laser beam and then scanning it plural times while shifting the position of laser beam scanning line, thus a remaining part 6 of the surface layer 4 of the surface treated layer is formed between respective scanning lines of the laser beam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser marking method and a workpiece to which marking is applied by the method, and more particularly, to irradiating a workpiece having a plurality of surface-treated layers with a laser beam. By cutting off the surface layer of the workpiece and exposing the underlying layer, a laser marking method for performing desired marking such as a figure on the surface of the workpiece and a workpiece which is marked by this method About things.

[0002]

2. Description of the Related Art Conventionally, a laser marking device for drawing predetermined characters or figures on the surface of a workpiece using a laser beam has been widely used. Many YAG lasers using an Nd: YAG crystal as an active medium from which an output is easily obtained are used.

In such a conventional laser marking device, the Q switch is operated in a state where sufficient excitation energy for oscillating predetermined solid-state laser light is accumulated in the YAG rod by irradiation with light from an excitation lamp. When the switch is turned off, the loss of the Q switch is set to 0, and the light traveling in the axial direction is allowed to pass through the output mirror without being diffracted and oscillate as a solid laser light at a stretch. And
By irradiating the surface of the workpiece with the solid-state laser light passing through the output mirror, the workpiece is marked.

Next, a case where marking is performed using such a laser marking device will be described.

FIG. 6 and FIG. 7 show such a conventional marking method.
A base layer 12 made of, for example, white paint is applied to the surface of a casing 11 made of a metal material such as stainless steel in which a predetermined semiconductor or an electric device or the like is housed like a C card or the like. The surface is subjected to a two-layer surface treatment, for example, by applying and forming a surface layer 13 made of gray paint.

[0006] In the case where such a conventional work piece 10 is to be marked, the surface of the work piece 10 is cut off only by irradiating the surface of the work piece 10 with laser light from the laser marking device. The underlying layer 12 is exposed. By exposing the underlayer 12 different in color from the surface layer 13 in this manner, a marked figure or the like can be recognized.

When marking a figure or the like in a range larger than a beam spot of a laser beam, such as a thick line portion of a bar code, on the surface of the workpiece 10, FIG. 6 and FIG. As shown in the figure, the laser beam emitted from the laser marking device is scanned, and scanning is performed a plurality of times while shifting the position so that scanning lines of the laser beam partially overlap. As a result, the entire surface layer 13 is scraped off in a desired range.

[0008]

However, in the above-described marking means, if the marking is performed so that the surface layer 13 is removed over a wide area of the workpiece 10 to expose the underlayer 12, the workpiece is processed. When the object 10 is touched, the finger may directly touch the exposed underlying layer 12 of the workpiece 10, and the strength of the underlying layer 12 is relatively low, so that the underlying layer 12 is peeled off. have. When the underlayer 12 is exposed, when an adhesive tape or the like comes into contact with the exposed underlayer 12,
There is a problem that the underlying layer 12 is easily peeled off by the adhesive force of the adhesive tape.

As described above, if the underlayer 12 of the workpiece 10 peels off, it becomes difficult to distinguish a marked figure or the like, and the appearance becomes dirty. And the like occurs. Furthermore, when the marking applied to the workpiece 10 is a bar code, the bar code cannot be read by a bar code reader when the underlayer 12 is peeled off.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has a laser marking method capable of preventing direct contact with an underlayer and reliably preventing peeling of the underlayer. It is an object of the present invention to provide a workpiece to which marking is applied.

[0011]

According to a first aspect of the present invention, there is provided a laser marking method, comprising: applying a laser beam to a workpiece on which a plurality of surface treatment layers are formed; By irradiating, the surface of the workpiece is scraped to expose the lower layer portion of the surface treatment layer, so that a laser marking method for performing a desired marking such as a figure on the surface of the workpiece is performed. On the surface of the, to scrape a range larger than the beam spot of the laser light, when marking a character or figure,
Scanning the laser light and scanning the laser light a plurality of times while shifting the position of the scanning line, so that a residual portion of the surface treatment layer is formed between the scanning lines of the laser light. It is a feature.

According to the first aspect of the present invention, by performing scanning a plurality of times while shifting the position of the scanning line of the laser beam, a residual portion of the surface treatment layer is formed between the scanning lines of the laser beam. With this configuration, when the workpiece is touched, the remaining portion can reliably prevent the finger or the like from directly touching the lower layer portion. As a result, it is possible to reliably prevent the lower layer having a relatively low strength from peeling off, to reliably determine the marked figure, etc., to have a clean appearance, and to further reduce the lower layer. Can reliably prevent the occurrence of rust and the like. Furthermore, since peeling of the lower layer portion can be reliably prevented, even if the marking on the workpiece is a barcode, the barcode can be reliably read by a barcode reader.

Further, the workpiece on which the marking according to the second aspect of the present invention has been applied is irradiated with a laser beam to scrape off the surface of the surface treatment layer comprising a plurality of layers, thereby forming a lower layer of the surface treatment layer. By exposing a part, on a workpiece on which a desired marking such as a figure is provided on the surface, when shaving a range larger than the beam spot of the laser beam on the surface, and marking a character or a figure, etc. In addition, while scanning the laser light, by scanning a plurality of times while shifting the position of the scanning line of the laser light, the residual portion of the surface treatment layer was formed between each scanning line of the laser light. It is a feature.

According to the second aspect of the present invention, since the residual portion of the surface treatment layer is formed between each scanning line of the laser beam on the surface of the workpiece, When touched, the remaining portion can reliably prevent the finger or the like from directly touching the lower layer portion. As a result, it is possible to reliably prevent the lower layer having a relatively low strength from peeling off, to reliably determine the marked figure, etc., to have a clean appearance, and to further reduce the lower layer. Can reliably prevent the occurrence of rust and the like. Furthermore, since peeling of the lower layer portion can be reliably prevented, even if the marking on the workpiece is a barcode, the barcode can be reliably read by a barcode reader.

[0015]

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

FIGS. 1 and 2 show an embodiment of a workpiece which has been marked by the laser marking method according to the present invention. The workpiece 1 according to the present invention comprises:
As shown in FIG. 1, for example, a base layer 3 made of, for example, a white paint is applied to the surface of a casing 2 made of a metal material such as stainless steel in which a predetermined semiconductor or an electric device such as a PC card is stored. At the same time, the surface of the underlayer 3 is coated with a surface layer 4 made of, for example, gray paint, and two surface treatment layers are formed. Then, the surface layer 4 of the workpiece 1 is removed by laser marking to expose the base layer 3, thereby performing marking so as to draw a desired figure or the like.

Further, a laser marking device (not shown) used in the laser marking method according to the present invention includes a YAG rod, which is one of the laser crystals having excellent optical characteristics, irradiated with light from an excitation lamp. In a state where sufficient excitation energy to oscillate a predetermined solid-state laser light is stored, the Q switch is turned off to reduce the loss of the Q switch to zero, and the light traveling in the axial direction is not diffracted. The laser beam is oscillated as a solid laser beam at a stretch by passing through an output mirror, and the solid laser beam passing through the output mirror can be irradiated.

Next, a laser marking method according to the present invention will be described.

In this embodiment, the thickness of the casing 2 of the workpiece 1 is, for example, 100 μm,
Is 10 μm, and the thickness of the surface layer 4 is about 10 μm.

First, when a range larger than the beam spot 5 of the laser beam, such as a thick line portion of a bar code, is cut out on the surface of the workpiece 1 to mark characters, figures, and the like. The laser beam emitted from the laser marking device is scanned, and scanning is performed a plurality of times while shifting the position of the scanning line of the laser beam.

In this case, in this embodiment, when scanning with laser light, scanning is performed such that scanning lines of the laser light do not overlap.

That is, as shown in FIGS. 1 and 2,
When marking the workpiece 1, for example, a beam spot 5 of a laser beam emitted from a laser marking device is used.
Is 70 μm, the scanning line pitch is about 0.1 μm.
By setting the diameter to about 1 mm and operating the laser marking device to irradiate the workpiece 1 with the laser beam, the laser beam is scanned so that only the surface layer 4 on the surface of the workpiece 1 is scraped off. Thus, the underlayer 3 is exposed, and marking of a desired shape is performed on the surface of the workpiece 1. In the present embodiment, by performing the marking by scanning the laser beam in this manner, the width dimension between each scanning line of the laser beam is 10 μm.
The remaining portions 6 of the surface layer 4 are formed in stripes.

In the present embodiment, since the remaining portion 6 is formed in a stripe shape in the marked figure, when the workpiece 1 is touched, the remaining portion 6
It is possible to reliably prevent a finger or the like from directly touching the base layer 3.

In the above-described embodiment, when the surface layer 4 is left, the marking is performed so that the remaining portion 6 is formed in a stripe shape.
As shown in FIG. 5, the residual portion 6 may be formed in a lattice shape, as shown in FIG. 4, the residual portion 6 may be formed in a dot shape, and further, in FIG. As shown,
The remaining portion 6 may be formed concentrically. The shape of the remaining portion 6 can be appropriately set according to the shape of the figure to be marked, etc., and not only each of the above-mentioned shapes, but also a combination of each shape, or any other shape Is also good.

According to the laser marking method of the present invention, the casing 2 made of stainless steel is used as the workpiece 1.
A 10 μm-thick underlayer 3 and a 10 μm-thick
Using a PC card which has been subjected to a two-layer surface treatment of the surface layer 4 of FIG.
Under the conditions that the frequency of the A and Q switches is 30 to 50 kHz, the scanning speed of the laser beam is 500 mm / s, and the beam spot diameter of the laser beam is 70 μm, the scanning line pitch of about 0.1 mm is applied to the workpiece 1. As a result of irradiating the laser beam in three times to mark the bar code so as to form the remaining portion 6 of the surface layer 4 in a stripe shape, the characters can be read well, and However, even when touched, extremely good marking without peeling of the underlayer 3 could be performed. In this case, the width dimension of the remaining portion 6 is about 10 μm, and even if such a remaining portion 6 is present, it is not very conspicuous in appearance, and even when reading a bar code marked with a bar code reader. There is no problem. Further, by irradiating the laser beam in three times, even when the thickness of the surface layer 4 or the underlayer 3 is extremely thin as in this embodiment, even the underlayer 3 is scraped off to expose the casing 2. Can be prevented,
In addition, it is possible to prevent discoloration of the underlayer 3 that occurs when marking is performed by irradiating a laser beam having a large output once.

Therefore, in the present embodiment, the remaining portion 6 is formed in the marked figure, and the remaining portion 6 reliably prevents a finger or the like from directly touching the base layer 3. As a result, the underlayer 3 having relatively low strength can be reliably prevented from peeling off, and a marked figure or the like can be reliably determined, and the appearance is beautiful. In addition, the generation of rust and the like in the underlayer 3 can be reliably prevented. Furthermore, since peeling of the underlayer 3 can be reliably prevented, even when the marking on the workpiece 1 is a barcode, the barcode can be reliably read by a barcode reader.

In the above embodiment, the case where the YAG laser is used as the laser has been described. However, the present invention is not limited to this, and any other laser may be used. Also, the laser excitation method is not limited to the lamp excitation method, but may be changed to any other laser excitation method such as a semiconductor laser excitation method.

The workpiece 1 is not limited to the underlayer 3 or the surface layer 4, but may be, for example, one having a plurality of surface treatment layers formed by painting three or more colors, or a metal. The present invention can be applied to any workpiece 1 as long as a plurality of surface-treated layers are formed, such as one obtained by performing a surface treatment such as rust prevention between a casing and a surface coating. .

Further, the present invention is not limited to the above-described embodiment, but can be changed as needed.

[0030]

As described above, in the laser marking method according to the first aspect of the present invention, by performing scanning a plurality of times while shifting the position of the scanning line of the laser beam, the laser marking method is performed between the scanning lines of the laser beam. Since the remaining part of the surface treatment layer is formed, when touching the workpiece,
The remaining portion can reliably prevent a finger or the like from directly touching the lower layer portion. As a result, it is possible to reliably prevent the lower layer having a relatively low strength from peeling off, to reliably determine the marked figure, etc., to have a clean appearance, and to further reduce the lower layer. Can reliably prevent the occurrence of rust and the like. Furthermore, since peeling of the lower layer portion can be reliably prevented, even if the marking on the workpiece is a barcode, the barcode can be reliably read by a barcode reader.

Further, in the workpiece to which the marking according to the second aspect of the present invention is applied, a residual portion of the surface treatment layer is formed between each scanning line of the laser beam on the surface of the workpiece. If you touch the workpiece,
The remaining portion can reliably prevent a finger or the like from directly touching the lower layer portion. As a result, it is possible to reliably prevent the lower layer having a relatively low strength from peeling off, to reliably determine the marked figure, etc., to have a clean appearance, and to further reduce the lower layer. Can reliably prevent the occurrence of rust and the like. Furthermore, since peeling of the lower layer portion can be reliably prevented, even when the marking applied to the workpiece is a bar code, the bar code reader can read the bar code reliably. .

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing an embodiment of a workpiece to be marked by a laser marking method according to the present invention.

FIG. 2 is an explanatory diagram showing one embodiment of a marking state of a workpiece by the laser marking method of the present invention.

FIG. 3 is an explanatory view showing another embodiment of a marking state of a workpiece by the laser marking method of the present invention.

FIG. 4 is an explanatory view showing another embodiment of a marking state of a workpiece by the laser marking method of the present invention.

FIG. 5 is an explanatory view showing another embodiment of a marking state of a workpiece by the laser marking method of the present invention.

FIG. 6 is a schematic configuration diagram showing a workpiece that has been marked by a conventional laser marking method.

FIG. 7 is an explanatory view showing a marking state of a workpiece by a conventional laser marking method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Workpiece 2 Casing 3 Underlayer 4 Surface layer 6 Remaining part

Claims (2)

[Claims] 1. A workpiece on which a plurality of surface treatment layers are formed is irradiated with laser light to scrape the surface of the workpiece and expose a lower layer of the surface treatment layer. In a laser marking method for performing a desired marking such as a figure on a surface of a workpiece, in a case where a larger area than the beam spot of the laser light is scraped on the surface of the workpiece to mark a character, a figure, or the like. In addition, while scanning the laser light, scanning is performed a plurality of times while shifting the position of the scanning line of the laser light so that a residual portion of the surface treatment layer is formed between the scanning lines of the laser light. A laser marking method, comprising: 2. A desired marking such as a figure is formed on the surface by irradiating a laser beam to scrape off the surface of the surface treatment layer comprising a plurality of layers to expose a lower layer portion of the surface treatment layer. In the workpiece, the surface of the workpiece is shaved off a region larger than the beam spot of the laser light, and when marking a character or a figure, the laser light is scanned and the position of the scanning line of the laser light is changed. A workpiece to which marking is applied, wherein a plurality of scans are performed while being shifted to form a residual portion of the surface treatment layer between each scan line of the laser beam.