JPH0616440A - Method for correcting defect on surface of transparent plate - Google Patents

Abstract

PURPOSE:To correct the defect on the surface of a transparent plate without impairing its light transmissivity by irradiating the hollow defect part formed on the surface of the transparent plate with an ArF excimer laser beam, thereby smoothing the defect part. CONSTITUTION:The hollow defect part 4 formed on the surface 2 of the transparent plate, such as glass plate, is irradiated with the ArF excimer laser beam 6. The defect part 4 is gradually chipped from the upper part 3 thereof and is made into the smooth surface on which the bottom 1 of the flaw 4 and the surface 2 of the transparent plate continue gently. The time is several tens seconds and is extremely short; in addition, the defect on the surface 2 of the transparent plate is corrected without impairing the light transmissivity of the worked surface. Extreme ruggedness is formed on the base of the worked part if a KrF excimer laser is used in place of the ArF excimer laser and, therefore, such laser is undesirable, as the light transmissivity is impaired.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for correcting defects on a plate surface made of a transparent material such as glass without impairing the light transmitting property.

[0002]

2. Description of the Related Art Defects such as scratches on the surface of a transparent plate such as a glass plate used in a liquid crystal display device are, for example, the surface of the transparent plate while rotating a grinder or the like containing a polishing liquid containing polishing powder. It is corrected by contacting with and mechanically polishing.

[0003]

However, such a method of correcting defects by mechanical polishing not only takes a very long time, but also glass powder or polishing powder generated by shaving the glass scatters to cause a display device. There is a problem in that these scattered substances enter the inside to cause a defect, and the working environment deteriorates. Further, when the LSI is mounted on the transparent plate, the mounted LSI may be destroyed by vibration or static electricity generated when the surface of the transparent plate and the grinder rub.

The present invention is intended to solve the above-mentioned drawbacks, and provides a method for correcting defects on the surface of a transparent plate in a short time without polishing by using polishing powder and without impairing translucency. The purpose is to

[0005]

In the polishing method of the present invention, a concave defect portion formed on the surface of a transparent plate is irradiated with an ArF excimer laser beam to smooth the defective portion, thereby achieving the above object. To be done.

[0006]

The ArF excimer laser can generate light in the ultraviolet region, and by irradiation with this ultraviolet light, the interatomic bond of the material forming the transparent plate is cut off, and the irradiated portion is scraped. The surface becomes almost flat, and the defects on the transparent plate surface are corrected without impairing the translucency.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

In the method of the present invention, as shown in FIG. 1, when a scratch 4 is formed on the glass plate surface 2, the scratch 4 is formed.
The ArF excimer laser beam 6 is irradiated from above.

When the scratches 4 are irradiated with the ArF excimer laser beam 6, the scratches 4 are gradually scraped from the upper part 3 of the scratches 4 instead of being deepened by being scraped as a whole, and finally, as shown in FIG. The bottom 1 of the scratch 4 and the surface 2 of the glass plate are smooth and smooth surfaces. The time is about several tens of seconds, which is a very short time, and the glass plate surface 2 can be polished without impairing the translucency of the processed surface.

The excimer laser is capable of generating a laser beam in the ultraviolet region, and the laser beam breaks the bonds between atoms of the workpiece, so that the surface of the workpiece can be irradiated without heat generation. It can be processed. When processing a transparent material such as glass, it is necessary to select a wavelength at which the laser beam is absorbed on the surface of the material, because the laser beam cannot pass through the glass and break the interatomic bond depending on the wavelength of the laser beam. The wavelength of the excimer laser varies depending on the type of gas used, but as shown in FIG. 3, when a flat glass plate surface 22 is cut using an ArF excimer laser, the bottom surface 21 of the cut portion is It becomes almost flat and the translucency is not impaired.

There is a KrF excimer laser as an excimer laser that generates a laser beam having a wavelength absorbed by a transparent material. When a flat glass plate surface 32 is cut using the KrF excimer laser, as shown in FIG. Since the roughened bottom surface 31 of the machined portion is formed, translucency is impaired.

When the defects on the surface of the glass plate are repaired by irradiating the ArF excimer laser beam, the edge 23 as shown in FIG. It is prevented from forming and defects in the glass sheet are well corrected.

At the time of defect correction, a small amount of scattered substances are generated when the glass is shaved, but it is greatly reduced as compared with the case of polishing with polishing powder. In order to prevent the scattered matter from adhering to the processed portion, it suffices to mask other than the laser beam irradiation portion.

[0014]

According to the present invention, since the processed surface can be made smooth by using the ArF excimer laser, the defect can be repaired without impairing the transparency of the transparent plate.

Since it is ground by laser beam irradiation, no friction occurs on the processed surface. So the quake,
Since no static electricity or the like is generated, even if the LSI is mounted on the transparent plate, there is no fear of destroying the LSI.

Further, although some scattered substances are generated during polishing, the amount is greatly reduced as compared with the conventional method using abrasive powder, so that the work can be performed in a clean state.

Further, since the defect can be repaired in a short time of about several tens of seconds, the work can be simplified and the time can be shortened.

[Brief description of drawings]

FIG. 1 is a schematic view showing how a surface of a glass plate is irradiated with ArF excimer laser.

FIG. 2 is a cross-sectional view of a glass plate after defect correction.

FIG. 3 is a cross-sectional view of a glass plate scraped using an ArF excimer laser.

FIG. 4 is a cross-sectional view of a glass plate scraped using a KrF excimer laser.

[Explanation of symbols] 2 glass plate surface 4 scratches 6 ArF excimer laser beam

Claims (1)

[Claims] 1. A is formed in a concave defect portion formed on the surface of a transparent plate.
A defect repair method for irradiating an rF excimer laser beam to smooth the defective portion.