JPS62203691A - Laser marking method - Google Patents

Abstract

PURPOSE:To improve the marking quality by coating the paint reflecting laser light on the surface of a base metal, by coating the paint absorbing the laser light on the upper layer thereof, then by projecting the laser light on the necessary part. CONSTITUTION:A white paint 2 becoming as the lower layer is coated on the surface of a base metal 1 and thereupon a paint 3 becoming the upper layer is coated. When a laser light 4 is projected on the necessary pattern part, then, the paint 3 absorbing the laser light 4 evaporates the projecting place only with its thermal energy. In this case, no thermal effect is caused on the base metal 1 with the laser light 4 being reflected almost by the white paint 2 even if excess laser energy is inputted. In this way, therefore, the laser mark of good contrast is formed and the quality in marking is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a laser marking method, and particularly to a method for forming a clear mark without producing a thermal shadow on a base material.

[Conventional technology]

In the conventional laser marking method, a mark is formed by irradiating a desired part of a base material with a laser beam to create a contrast between the mark part that thermally changes the base material and other parts. Further, related to the conventional laser marking method, there is a method for marking semiconductor devices described in Japanese Patent Application Laid-Open No. 60-204392.

[Problem that the invention seeks to solve]

In the conventional laser marking method as described above, thermal energy is applied to the base material, so that the thermal influence may extend to the vicinity of the mark portion.

Further, there was a problem in that the contrast between the mark portion where the base material was thermally altered and other portions was small, making it difficult to recognize the mark portion.

This invention was made in view of the above-mentioned problems, and aims to provide a laser marking method that can prevent heat energy from being applied to the base material and form a high-quality mark that is easy to recognize. There is.

[Means for solving problems]

It consists of a step of applying a paint that reflects laser light, a step of applying a paint that absorbs laser light as an upper layer, and a step of removing the applied paint layer of the base material in a desired pattern by irradiation with laser light. It is something.

[Effect]

In this invention, since a paint that reflects laser light is applied to the base material, even if not only an appropriate amount of laser energy but also an excessive amount of laser energy is applied, most of the laser light will be reflected by the paint that reflects the laser beam. The pattern becomes clearer without damaging the material.

〔Example〕

FIG. 1 is a sectional view showing a state in which a υ base material is marked by a laser marking method according to an embodiment of the present invention;
FIG. 2 is a sectional view showing a base material used in the same laser marking method. In the figure, (1) is the base material, (2)
(3) is a paint that absorbs laser beams other than white, (4) is a laser beam, and (5) is an exposed part of the white paint.

Next, the laser marking method of this embodiment will be explained.

First, as shown in FIG. 1, a white paint (2) as a lower layer is applied to the surface of a base material (1). If the substrate (1) is white, there is no need to apply white paint (2). and,
The coating material (3) f, which becomes the upper layer, is applied to the coated base material (1).

Next, as shown in FIG. 2, a desired pattern portion is irradiated with a laser beam (4). The laser beam (4) is absorbed by the paint (3) and becomes thermal energy, which evaporates the room material (3) in the area irradiated with the laser beam (4). Even if excessive laser energy is applied at that time, most of the laser light (4) is reflected by the white paint (2), so the base material (1)
By exposing the white paint (2), a laser mark with good contrast is formed without any thermal effect on the surface.

Note that the paint that reflects the laser beam that forms the lower layer is white paint (
2) is not necessary, and it goes without saying that the same effect as in the above embodiment can be obtained if the color is a white color such as cream color.

〔Effect of the invention〕

As explained above, this invention first coats the surface of the base material with a paint that reflects laser light, and then uses the paint to reflect most of the laser light, so that a desired pattern can be created. This has the effect of forming markings with good contrast without thermally affecting the base material.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a state in which a base material is marked by a laser marking method according to an embodiment of the present invention;
FIG. 2 is a sectional view showing a base material used in the same laser marking method. In the figure, (1) is the base material, (2) is white paint (paint that reflects laser light), (3) is paint (paint that absorbs laser light), and (4) is laser light. Note that in each figure, the same reference numerals indicate the same or equivalent parts.O Agent Patent Attorney Masaru Sato Figure 1 Figure 1 = Base material 2 Two units Diagonal 3: Pupil Department 4: Laser beam f82 diagram

Claims (2)

[Claims] (1) Apply a paint that absorbs laser light as an upper layer and a paint that reflects laser light as a lower layer to the surface of the base material, and apply the laser beam to only the desired areas. A laser marking method characterized by removing only the upper layer of paint. (2) The laser marking method according to claim 1, wherein the paint that is applied to the surface of the base material and serves as a lower layer that reflects laser light is a white paint.