CN112192055B

CN112192055B - Laser processing method and laser processing apparatus

Info

Publication number: CN112192055B
Application number: CN202010649379.4A
Authority: CN
Inventors: 伊藤靖; 市川健一; 佐伯勇辉; 西部达矢
Original assignee: Via Mechanics Ltd
Current assignee: Via Mechanics Ltd
Priority date: 2019-07-08
Filing date: 2020-07-08
Publication date: 2024-06-18
Anticipated expiration: 2040-07-08
Also published as: JP7251904B2; TWI821580B; KR20210006294A; JP2021011410A; CN112192055A; TW202103831A

Abstract

The purpose of the present invention is to detect that a hole has been penetrated, particularly when a glass substrate is perforated with a laser beam. The solution is as follows: a laser processing device includes: a table on which a substrate to be processed is placed; a laser irradiation system for irradiating the substrate with laser light; and a control unit for controlling the respective parts of the apparatus for performing the machining operation; wherein the control part detects that the hole is penetrated by detecting that the light detection level at the end face of the substrate is reduced to a predetermined level during the processing operation.

Description

Laser processing method and laser processing apparatus

Technical Field

The present invention relates to a laser processing method and a laser processing apparatus, and more particularly, to a laser processing method and a laser processing apparatus capable of detecting penetration of a hole when a glass substrate is perforated with a laser.

Background

When a hole is drilled by a laser, it is desirable to reliably detect that the hole has been penetrated. As means for verifying whether or not the machining operation is performed normally, there are, for example, a method of accumulating machining power for each hole and comparing it with a predetermined value as disclosed in patent document 1, and a method of measuring the reflection intensity when irradiating laser light for each hole and comparing it with a predetermined value as disclosed in patent document 2.

Patent literature

Patent document 1: japanese patent laid-open No. 9-308977

Patent document 2: japanese patent application laid-open No. 2004-9074

Disclosure of Invention

Problems to be solved by the invention

In the method, only whether the laser is normally irradiated is determined, and is not used for detecting that holes are drilled or even penetrated.

Accordingly, an object of the present invention is to detect that a hole is penetrated, particularly when a glass substrate is perforated by a laser beam.

Means for solving the problems

In a representative laser processing method disclosed by the application, a through hole is drilled in a substrate by irradiating laser, wherein the through hole is detected by detecting a light detection level at an end surface of the substrate during a processing operation and detecting that the light detection level has been lowered to a predetermined level.

Efficacy of the invention

According to the present invention, when a hole is formed in a glass substrate by laser, it is possible to detect that the hole is penetrated.

Drawings

Fig. 1 is a diagram for explaining a penetration determination operation in an embodiment of the present invention.

Fig. 2 is a schematic block diagram of a laser processing apparatus according to an embodiment of the present invention.

Fig. 3 is a diagram for explaining an example of drilling.

Figure 4 shows a cross-sectional view of the shape of a hole being processed in an embodiment of the invention.

Description of the reference numerals

1. Glass substrate

2. Working table

4. Control unit

5. Laser irradiation system

6 UV laser

8. Optical sensor

9. End face

10. Hole(s)

Detailed Description

An embodiment of the present invention will now be described.

Fig. 2 is a schematic block diagram of a laser processing apparatus according to an embodiment of the present invention. The respective constituent elements and connecting lines are mainly represented as being considered necessary for the description of the present embodiment, and are not represented as all essential elements of the laser processing apparatus.

In fig. 2, a glass substrate 1 is placed on a table 2 of a laser processing apparatus through an adsorption jig 3, and a plurality of holes are drilled by irradiation of UV laser light 6 from a laser irradiation system 5 under the control of a control unit 4 that controls the operations of the respective parts of the apparatus.

The suction jig 3 plays the following roles: the glass substrate 1 is sucked from below by the suction holes 7 provided in the glass substrate itself, and is prevented from floating. The control unit 4 makes the following: the present invention is configured to be mainly composed of a programmed processing device, and to have a control function other than the functions described herein, and to be connected to a block not shown.

The construction described thus far is well known in the art. The reference numeral 8 denotes an optical sensor, which is disposed in contact with the end face 9 of the glass substrate 1 and detects the magnitude of light refracted by the end face 9. In this case, the optical sensor 8 may have a plurality of light detection elements arranged side by side along the end face 9 of the glass substrate 1 to improve sensitivity.

The control unit 4 can determine the state of penetration of the hole by a detection signal from the optical sensor 8, as will be described later.

The control unit 4 is configured to perform continuous laser irradiation on a plurality of positions around a position to be drilled by the operation of each part of the control device, and to drill through holes (hereinafter, processing performed by continuously irradiating a plurality of positions of one hole is referred to as drilling processing).

As a method of drilling, there are a method of gradually changing a position so as to draw a spiral (helical) trajectory, and a method described below: as shown in fig. 3, after repeating the laser irradiation S so as to draw a circle with the center P of the position to be perforated as the center, the radius of the circle is gradually changed and the same is repeated.

When the UV laser light 6 is irradiated to the glass substrate 1, the UV laser light 6 is refracted inside the glass substrate 1 and is incident on the end face 9 of the glass substrate 1. Fig. 4 (a) shows that when irradiation of the glass substrate 1 is started, the refractive light toward the end face 9 of the glass substrate 1 is strong at this time. However, since the glass portion at the hole position gradually decreases as the processing proceeds thereafter, the refractive light toward the end face 9 also gradually decreases. Fig. 4 (b) shows a state when the hole 10 penetrates.

The refractive light toward the end face 9 of the glass substrate 1 is not changed only at the time of starting irradiation and at the time of penetration, but also at the time of different hole positions or different numbers of penetrated holes.

Then, in the present embodiment, for the glass substrate to be drilled, the output level of each optical sensor 8 in the through state (hereinafter referred to as the through level) is detected for all holes by experiments in advance or the like, and the lowest output level (hereinafter referred to as the lowest through level) among them is grasped, whereby when the output level gradually decreases as the drilling process proceeds and reaches the lowest through level, it is determined that the hole has been penetrated.

Since the penetration level varies depending on the hole position or the number of holes penetrated, if it is determined that the hole is penetrated when the lowest penetration level is reached as described above, the penetration can be reliably detected at any hole position.

Fig. 1 is a diagram for explaining the penetration determination operation in the control unit 4.

Fig. 1 (a) shows a state of one hole position in the glass substrate 1. The control unit 4 monitors the output level V of the optical sensor 8 at the start of irradiation of the UV laser light 6, and determines that the hole is penetrated when the output level V gradually decreases as the drilling process proceeds to reach the minimum penetration level L.

When the control unit 4 determines that the hole is penetrated, the laser irradiation system 5 stops irradiating the laser beam to the hole, and starts irradiating the laser beam to the next hole.

Fig. 1 (b) shows a state of other hole positions in the glass substrate 1. Here, the control unit 4 monitors the output level V of the optical sensor 8 at the start of irradiation of the UV laser light 6, and determines that the hole is penetrated when the output level V gradually decreases with the progress of the drilling process and reaches the minimum penetration level L.

When the control unit 4 determines that the hole is penetrated, the laser irradiation system 5 stops irradiating the laser beam to the hole and starts irradiating the laser beam to the next hole similarly to the above.

In the above embodiment, by grasping the lowest through level L in advance, when the output level V gradually decreases as the drilling proceeds and reaches the lowest through level L, it is determined that the hole is through, but it may be determined that the hole is through by other methods.

For example, by an experiment or the like in advance, it is possible to detect how much the output level V of the optical sensor 8 at the time of penetration is reduced from the output level V of the optical sensor 8 at the time of starting irradiation of the laser beam (hereinafter referred to as a penetration ratio), grasp the lowest ratio (hereinafter referred to as the lowest penetration ratio), and determine that the hole is penetrated when the output level V gradually decreases as the drilling process proceeds and reaches the lowest penetration ratio. In this method, the penetration can be detected reliably at any hole position, and thus it is determined that the hole is penetrated when the minimum penetration ratio is reached.

Incidentally, in the case of this method, the output level V of the optical sensor 8 immediately after the start of the irradiation of the laser light may be selected instead of the output level V of the optical sensor 8 at the start of the irradiation of the laser light. Further, if the output level V at the time of penetration is excessively smaller than that before penetration, the output level of the optical sensor 8 at a time immediately after the start of irradiation of the laser light may be selected.

Incidentally, in the above embodiment, as long as the size, hole position, hole size, hole opening order, and specification of the glass material of the glass substrate 1 are not changed, the lowest penetration level L or the lowest penetration ratio is of course the same. Accordingly, it is not necessary to grasp the minimum penetration level L or the minimum penetration ratio of each perforated glass substrate 1 in advance, and it is only necessary to grasp the standard of one glass substrate 1 in the range where the specification is not changed.

However, if it is desired to avoid a slight change in each glass substrate 1, for example, the minimum penetration level L or the minimum penetration ratio of each batch may be grasped in advance.

Further, in the above embodiment, the case of performing the drilling processing of the UV laser 6 is described, but in the present invention, the CO ₂ laser may be used instead of the UV laser 6, or so-called punching processing may be performed; wherein, the punching processing is to perform one-time irradiation on one hole position or perform multiple-time irradiation on the same place.

Claims

1. A laser processing method for drilling a through hole in a substrate by irradiating the substrate with laser light, characterized in that a light detection level at an end surface of the substrate during a processing operation is detected, and the through hole is detected by detecting that the light detection level has been lowered to a predetermined level.

2. A laser processing method for drilling a through hole in a substrate by irradiating the substrate with laser light, characterized in that a light detection level at an end surface of the substrate during a processing operation is detected, and the through hole is detected by detecting that the light detection level has been reduced to a predetermined ratio with respect to a level before the through hole.

3. The laser processing method according to claim 2, wherein the pre-penetration is defined as when irradiation of laser light is started.

4. A laser processing apparatus, comprising: a table on which a substrate to be processed is placed; a laser irradiation system for irradiating the substrate with laser light; and a control unit for controlling the respective parts of the apparatus for performing the machining operation;

The control unit detects that the hole is penetrated by detecting that the light detection level at the end face of the substrate has been lowered to a predetermined level during the processing operation.

5. A laser processing apparatus, comprising: a table on which a substrate to be processed is placed; a laser irradiation system for irradiating the substrate with laser light; and a control unit for controlling the respective parts of the apparatus for performing the machining operation;

The control unit detects that the hole is penetrated by detecting that the light detection level at the end surface of the substrate has decreased to a predetermined ratio with respect to the level of the hole before penetration during the processing operation.

6. The laser processing apparatus according to claim 5, wherein the pre-penetration is defined as when irradiation of the laser light is started.