JPH1158050A - Division of ceramic substrate using laser and its laser scriber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide such a laser scriber for dividing a ceramic substrate that contamination of a condensing lens and a ceramic substrate is suitably prevented, at the time of forming on the ceramic substrate a ruled line for breaking constituted of a chain of plural recessed through the converged laser beam. SOLUTION: By injecting a gas from a gas injection nozzle 50a to the direction against a laser beam L within a plane vertical to the laser beam L between the through-hole 34 of a lens hood 36 and a ceramic substrate 12, and bending sideways the direction of the entrainers H that goes upward from the condensing point P of the laser beam L on the ceramic substrate 12, thereby contamination of the condensing lens 32 is adequately prevented. In addition, since the flying distance of the entrainer H from the ceramic substrate 12 is lengthened on account of the gas injection, the cooling of the entrainers is promoted advantageously to limit the sticking of the entrainers H only near the condensing point P of the laser beam L.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic substrate dividing method for dividing a ceramic substrate using a laser beam and a laser scriber for dividing a ceramic substrate.

[0002]

2. Description of the Related Art In order to divide a ceramic substrate, a condenser lens facing the ceramic substrate, and a lens hood having a through hole in a portion corresponding to the optical axis of the condenser lens to cover the condenser lens are provided. A gas supply device for supplying gas into the lens hood for injecting gas toward the ceramic substrate through the through hole, by condensing laser light on the ceramic substrate with a predetermined spot diameter,
There is known a laser scriber which forms a break ruled line composed of a series of a large number of concave holes before dividing the ceramic substrate. According to such a laser scriber, since the laser scriber is easily broken along the breaking ruled line, a large substrate is divided into a plurality of substrates of a predetermined size.

[0003]

However, in the conventional laser scriber, when the ceramic substrate is locally melted and evaporated by condensing the laser beam to form a concave hole, the ceramic substrate is splashed. Is scattered in the vertical direction, and although gas is ejected from the lens hood to the outside through the through hole, it adheres to the condenser lens through the through hole, contaminating the condenser lens and causing laser light There was a problem that the output decreased. In addition, when a concave hole is formed by local melting and evaporation of the ceramic substrate due to the condensing of the laser light, when the ceramic substrate is scattered and splashed, after passing the laser light irradiation point, There is a problem that the surface of the ceramic substrate is contaminated by the splash. Such droplets have a relatively large adhesive force to the ceramic substrate, and thus are not easily removed by washing or the like. And due to such contamination,
For example, when a thick-film conductor is formed on a ceramic substrate, uniform solder plating on the thick-film conductor becomes impossible, or when a bonding pad is formed on the ceramic substrate, bonding becomes impossible. Inconvenience may occur.

The present invention has been made in view of the above circumstances, and an object of the present invention is to form a break ruled line composed of a series of a large number of concave holes on a ceramic substrate by condensing a laser beam. In this regard, it is an object of the present invention to provide a ceramic substrate dividing method and a laser scriber for dividing a ceramic substrate using a laser beam in which contamination of a condenser lens and a ceramic substrate is suitably prevented.

[0005]

A first aspect of the present invention for achieving the above object is to provide a condenser lens facing a ceramic substrate and a portion corresponding to an optical axis of the condenser lens. A lens hood having a through-hole and covering the condenser lens, and a gas supply device for supplying gas into the lens hood to inject gas toward the ceramic substrate through the through-hole, Using a laser beam irradiator that focuses the laser beam on the ceramic substrate at the spot diameter, irradiating the laser beam prior to the division of the ceramic substrate, a break ruled line composed of a series of many concave holes is formed. A method of dividing a ceramic substrate using a laser formed on a ceramic substrate, comprising:
A step of forming the breaking ruled line in one direction by relatively moving the ceramic substrate and an irradiation point of a laser beam on the ceramic substrate; and (b) the lens hood during the ruled step. A gas injecting step of injecting a gas in a direction toward the laser beam between the through-hole and the ceramic substrate.

[0006]

According to the first aspect of the present invention, in the gas jetting step, the gas is jetted in the direction toward the laser beam between the through hole of the lens hood and the ceramic substrate during the crease step. From the above, even if the droplets from the ceramic substrate are scattered to the condenser lens side when the concave hole is formed by the local melting and evaporation of the ceramic substrate caused by the focusing of the laser light, Since the direction of the droplets on the ceramic substrate is bent by the gas injection, the contamination of the condenser lens due to the droplets is suitably prevented. In addition, the above-mentioned gas injection increases the flight distance of the droplets from the ceramic substrate, which promotes cooling of the droplets.When the droplets fall on the ceramic substrate, they reach a temperature at which they do not adhere to the ceramic substrate, and are easily removed by washing or the like. It will be in the state to be performed.

[0007]

A converging lens fixed to an injection cylinder through which a laser beam penetrates so as to face a ceramic substrate, and a through hole is formed in a portion corresponding to the optical axis of the converging lens. A lens hood provided in the injection cylinder so as to cover the condenser lens, and a gas supply device for supplying gas into the lens hood to inject gas toward the ceramic substrate through the through hole. A laser beam is focused on the ceramic substrate at a predetermined spot diameter prior to the division of the ceramic substrate, thereby forming a break ruled line formed of a series of a large number of concave holes on the ceramic substrate. A ceramic substrate dividing laser scriber, (a) a cover member provided in the injection cylinder to cover a space between the lens hood and the substrate, (b) A gas injection device provided on the cover member for injecting gas in a direction toward the laser beam between the through hole of the lens hood and the ceramic substrate.

[0008]

According to this structure, the cover member provided in the injection cylinder for covering the space between the lens hood and the substrate is provided between the through hole of the lens hood and the ceramic substrate. Since the gas injection device that injects gas in the direction toward the laser light is provided, when the ceramic substrate is locally melted and evaporated by the condensing of the laser light, a concave hole is formed. Even if the droplets from the ceramic substrate are scattered to the condenser lens side, since the direction of the droplets on the ceramic substrate is bent by the gas injection by the above-described gas injection device, the contamination of the condenser lens due to the droplets is suitably prevented. Is done. In addition, the above-mentioned gas injection increases the flight distance of the droplets from the ceramic substrate, promotes cooling of the droplets, and suitably reduces the droplet adhesion range on the ceramic substrate.

[0009]

Another aspect of the present invention, in the first and second inventions, preferably, the gas ejecting step is performed between the through hole of the lens hood and the ceramic substrate during the crease step. Direction toward the laser light,
The gas is jetted in a direction that is at an acute angle with respect to the moving direction of the laser beam converging point. Further, the gas ejecting device is provided on the cover member, in a direction toward the laser light between the through hole of the lens hood and the ceramic substrate, and in a moving direction of a focal point of the laser light. The gas is injected in a direction at an acute angle to the gas. Sprays generated from the ceramic substrate at the focal point of the laser beam tend to be generated more in the direction of movement of the focal point. As a result, the range of adhesion of the droplets on the ceramic substrate can be reduced.

In the first invention and the second invention, preferably, the gas injection step is perpendicular to a laser beam between the through hole of the lens hood and the ceramic substrate during the crease step. The gas is ejected in a direction toward the laser light within a plane and at an acute angle with respect to the moving direction of the focal point of the laser light. Further, the gas ejecting device is provided on the cover member, in a direction toward the laser light in a plane perpendicular to the laser light between the through hole of the lens hood and the ceramic substrate, wherein the laser This is to inject gas in a direction that is at an acute angle to the moving direction of the light converging point. According to this configuration, when the laser light is applied to the ceramic substrate in the vertical direction, the gas injection is performed in parallel to the ceramic substrate, that is, in the horizontal direction. There are advantages to be made.

In the second invention, preferably,
The injection cylinder of the laser scriber and the cover member provided on the laser scriber are fixed in position, and the gas injection device has four positions at equal angular intervals around the laser light emitted from the injection cylinder. Injection direction is X
XY provided on the cover member so as to form an angle of approximately 45 ° with respect to the axis and the Y axis, and further moving the ceramic substrate in a two-dimensional coordinate plane including an X axis and a Y axis orthogonal to each other. The table includes a table and an injection control device that injects gas from at least one of a pair of gas injection devices that oppose the moving direction of the ceramic substrate among the gas injection devices provided at the four positions. With this configuration, there is an advantage that the gas is injected from the gas injection device under the same conditions in the moving direction of the ceramic substrate regardless of the moving direction of the ceramic substrate.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a laser scriber 10 for dividing a ceramic substrate to which the present invention is applied and a method for dividing a ceramic substrate using the laser scriber 10 will be described in detail.

FIG. 1 shows a laser scriber 10 used for dividing a ceramic substrate 12 such as an alumina substrate having a large number of thick film circuits and thin film circuits formed on one surface, and an alumina substrate having one surface polished. FIG. 3 is a diagram illustrating a main part of the configuration. In FIG. 1, a laser scriber 10
Includes an XY table 16 provided on a base 14 for moving the ceramic substrate 12 placed on the upper surface in the X-axis direction and the Y-axis direction. The XY table 16 is guided on the base 14 in the Y-axis direction and is positioned by the Y-axis motor 18. The XY table 16 is guided on the Y-axis table 20 in the X-axis direction. And an X-axis table 24 positioned by the axis motor 22. On the upper surface of the X-axis table 24, a positioning corner (not shown) for abutting and positioning the ceramic substrate 12 and a suction hole for adsorbing and fixing the ceramic substrate 12 are provided as necessary.

The laser scriber 10 has a thickness of 10.6 μm.
a CO ₂ laser oscillating device 26 that outputs a laser beam L having a wavelength of about m, and an injection cylinder 30 that houses a reflecting device 28 that guides the laser beam L and reflects the laser beam L in a direction perpendicular to the traveling direction. A condenser lens 32 provided at an end of the injection cylinder 30 for condensing the laser light L on the ceramic substrate 12; A lens hood 36 provided with a through hole 34 at a portion corresponding to the optical axis to cover the condenser lens 32; and a lens hood 36 provided at the end of the injection cylinder 30 to cover the space between the lens hood 36 and the ceramic substrate 12. And the cover member 38 are fixedly provided. The above C
O ₂ laser oscillation device 26, injection cylinder 30, condenser lens 32
And the like constitute a laser beam irradiation device provided at a fixed position.

As shown in detail in FIG. 3, the lens hood 36 has a tapered cylindrical shape whose diameter decreases from the base fixed to the injection cylinder 30 toward the tip on the ceramic substrate 12 side. It is formed concentrically. The lens hood 36 outputs a first pressure gas (eg, dry air, nitrogen, carbon dioxide gas, etc.) of about 4 kg / cm ² , for example.
Connected to a gas supply device 39 via a pipe 40,
The above-mentioned pressurized gas is constantly jetted toward the ceramic substrate 12 as an auxiliary gas for scribing through the through hole 34 of the lens hood 36, and
The condensing lens 32 is prevented from being contaminated by water droplets.

As shown in detail in FIGS. 2 and 3, the cover member 38 is formed in a cylindrical shape having a bottom with a cylindrical outer peripheral wall 42 and a bottom wall 44 closing the upper end of the outer peripheral wall 42. The injection cylinder 30 is inserted into the through-hole 46 formed in the bottom wall 44 of the injection cylinder 30.
It is fixed to 0. Furthermore, the cover member 38 is provided with four electromagnetic on-off valves 48 from the second gas supply device 46.
Four gas injection devices 50a, 50b to which a pressure gas lower than the pressure gas, for example, a pressure gas of about 1 kg / cm ² (eg, dry air, nitrogen, carbon dioxide gas, etc.) is supplied via a, 48b, 48c, 48d. , 50c, 50d are directed toward the laser light L in a plane perpendicular to the laser light L emitted from the injection cylinder 30 toward the ceramic substrate 12 and with respect to the X axis and the Y axis. They are provided at equal angular intervals so as to form an acute angle, for example, approximately 45 °. The cover member 38 is formed of a transparent member such as an acrylic resin in order to enhance workability.

Further, the outer peripheral wall 42 of the cover member 38
Is provided with a duct connection pipe 52, and the cover member 3
Inside 8 is connected via a duct 54 connected to the duct connection pipe 52 to a dust collecting device 56 for collecting splashes and dust generated from the ceramic substrate 12.

The laser scriber 10 includes:
A control device 60 is provided for starting scribing of the ceramic substrate 12 placed on the XY table 16 in response to operation of a start operation button (not shown). The control device 60 stores, for example, preset division lines, ie, break ruled lines, scribing conditions, and the like. The control device 60 is provided on the ceramic substrate 12 placed on the XY table 16. The ceramic substrate 12 is moved by, for example, 4 m / min in the X-axis direction and the Y-axis direction with respect to the irradiation point of the laser beam L in order to draw a ruled line for breaking on the ceramic substrate 12 based on the positioning mark thus set.
By causing the laser beam L to be output at a predetermined frequency from the CO ₂ laser oscillation device 26 while relatively moving at a speed of the order of, for example, as shown in FIG. 4 and FIG. 160μm
Breaking rule lines 64 formed of a series of a large number of concave holes 62 at approximately regular intervals are formed on the ceramic substrate 12. The breaking rule 64 is formed, for example, between a plurality of thick film circuits formed on one surface of the ceramic substrate 12 and is divided from the ceramic substrate 12 into individual thick film circuit boards after the formation of the thick film circuit. Used for The diameter and interval of the concave hole 62 are determined by the diameter of the converging point P of the laser beam L and the laser beam L.
Is larger or smaller than the above value according to the intensity of the laser beam L and the relative moving speed of the converging point P of the laser beam L.

Here, when the breaking ruled line 64 is formed as described above, a minute area irradiated with the laser beam L on one surface of the ceramic substrate 12 is heated to about 3500 ° C. The above-mentioned concave hole 62 is formed by melting and evaporating. The splash from the ceramic substrate 12 passes through the through hole 34 regardless of the outflow of the pressurized gas from the through hole 34 of the lens hood 36. To the condenser lens 32, and the condenser lens 32 is contaminated. Further, there is a problem that the splash from the ceramic substrate 12 also adheres to a place distant from the irradiation point of the laser beam L, thereby impairing uniform solder wetting of the thick film circuit. For this reason, in the laser scriber 10 of the present embodiment,
Four gas injection devices 50a, 50b, 50c, 50d are provided on the cover member 38, and the gas injection devices 50
a, 50b, 50c, and 50d can be switched in accordance with the moving direction of the ceramic substrate 12.

That is, the control device 60 irradiates the ceramic substrate 12 placed on the XY table 16 with the laser beam L while moving the ceramic substrate 12 in the X-axis direction or the Y-axis direction. During the execution of the crease step of forming the breaking ruled line 64 on the ceramic substrate 12, the electromagnetic opening / closing valves 48 a, 48 b, 48 c, 48 d are switched according to the moving direction of the ceramic substrate 12, whereby the through hole 34 of the lens hood 36 is formed. And ceramic substrate 1
2 is a direction toward the laser light L in a plane perpendicular to the laser light L, and the focal point P of the laser light L
Gas injection devices 50a, 50b, 50c, 50 so as to be at an acute angle to the moving direction of
A gas injection step of injecting a pressurized gas from any one of d.

In FIG. 2, for example, during a period in which the converging point (scribe point) P of the laser beam L is moved in the + X direction, that is, a period in which the ceramic substrate 12 is moved in the -X direction, With solenoid on-off valve 4
8a is opened and gas is injected from the gas injection device 50a. Further, the focal point (scribe point) P of the laser beam L is +
During the period in which the ceramic substrate 12 is moved in the −Y direction, that is, in the period in which the ceramic substrate 12 is moved in the −Y direction, the control device 60 opens the electromagnetic on-off valve 48b and the gas is injected from the gas injection device 50b. Further, during a period in which the converging point (scribed point) P of the laser beam L is moved in the −X direction, that is, a period in which the ceramic substrate 12 is moved in the + X direction, the control device 60 controls the electromagnetic on-off valve 48 c to operate. When opened, gas is injected from the gas injection device 50c. Further, during a period in which the converging point (scribe point) P of the laser beam L is moved in the −Y direction, that is, a period in which the ceramic substrate 12 is moved in the + Y direction, the control device 60 sets the electromagnetic on-off valve 48d to be in the −Y direction. It is opened and gas is injected from the gas injection device 50d.

As described above, the gas injection devices 50a, 50b are arranged so as to be directed toward the laser light L in a plane perpendicular to the laser light L between the through hole 34 of the lens hood 36 and the ceramic substrate 12. , 50c, and 50d, the direction of the upward droplet H from the focal point P of the laser beam L on the ceramic substrate 12 is bent laterally as shown in FIG. In addition, contamination of the condenser lens 32 is suitably prevented. Further, since the flight distance of the droplet H from the ceramic substrate 12 is increased by the above-described gas injection, cooling of the droplet is promoted, and when the droplet H falls on the ceramic substrate, the temperature becomes a temperature at which the droplet does not adhere to the ceramic substrate. Since the droplet H is easily removed, there is an advantage that the adhesion of the droplet H remains only near the converging point P of the laser beam L.

The gas injection step of this embodiment is directed to the laser beam L between the through hole 34 of the lens hood 36 and the ceramic substrate 12 during the crease step. The gas is ejected in a direction that is at an acute angle with respect to the moving direction of the light converging point P. The gas injection devices 50a, 50b, 50c, and 50d are directed toward the laser light L between the through hole 34 of the lens hood 36 and the ceramic substrate 12 and move in the direction of the focal point P of the laser light L. The gas is injected in a direction at an acute angle to the gas. The droplets H generated from the ceramic substrate 12 at the focal point P of the laser beam L tend to be generated in the moving direction side of the focal point P. The contamination of the ceramic substrate 12 is further reduced, and the range of the splash adhesion on the ceramic substrate 12 is suitably reduced.

Further, in the gas injection step of this embodiment, the through hole 3 of the lens hood 36 is used during the crease step.
The gas is directed in a direction toward the laser light L in a plane perpendicular to the laser light L between the substrate 4 and the ceramic substrate 12 and at an acute angle with respect to the moving direction of the focal point P of the laser light L. Is to be injected. Further, the gas injection devices 50a, 50b, 50c, and 50d are provided with the lens hood 3
6 in a direction perpendicular to the laser light L between the through hole 34 and the ceramic substrate 12 and toward the laser light L, and at an acute angle to the moving direction of the focal point P of the laser light L. Injects gas in a certain direction. For this reason, when the laser beam L is applied to the ceramic substrate 12 from the vertical direction, the gas injection is performed on the ceramic substrate 1.
2 is performed in parallel, that is, in the horizontal direction, so that there is an advantage that the collection of the droplet H by the dust collecting device 56 is suitably performed.

Further, according to the present embodiment, the four gas injection devices 50a, 50b, 50c, 50d
The cover member 38 has four positions at equal angular intervals around the laser beam L emitted from 0, and the emission direction is at an angle of approximately 45 ° with respect to the X axis and the Y axis.
, And four gas injection devices 50a, 50b, 50c, provided at the four positions, respectively.
Since the injection control device 60 that injects gas from at least one of a pair of gas injection devices facing the moving direction of the alumina substrate 12 among 50d is provided, regardless of the moving direction of the alumina substrate 12, There is an advantage that the gas is injected from the gas injection device under the same conditions with respect to the moving direction of the substrate 12.

While the embodiment of the present invention has been described with reference to the drawings, the present invention can be applied to other embodiments.

For example, the laser scriber 10 of the above-described embodiment uses the X-Y table 16 for the ceramic substrate 12 with respect to the laser light L emitted from the injection cylinder 30 whose position is fixed.
However, the laser beam L may be relatively moved with respect to the fixed ceramic substrate 12 by a deflecting device or the like.

Further, the gas injection device 50 of the above-described embodiment is used.
Although a, 50b, 50c, and 50d are respectively provided on the cover member 38, they may be provided on other members such as a support bracket, or may be provided on the gas injection devices 50a and 50d.
Ob, 50c, and 50d do not necessarily need to be provided at four positions. If the scribing direction is limited, it is only necessary to provide a number corresponding thereto.

The gas injection devices 50a, 50
b, 50c, and 50d do not necessarily need to be injected in a plane perpendicular to the laser beam L, and may be inclined to some extent.
The angles of the irradiation points P of the laser beams L of the laser beams L of the laser beams 50b, 50c, and 50d do not necessarily have to be acute angles. . However, according to the experiments performed by the present inventors, if the acute angle is 90 ° or less, the effect of reducing the attachment range (attachment distance) of the droplet H centered on the condensing point P on the ceramic substrate 12 is observed. In the range of from 75 ° to 75 °, the range of attachment of the droplet H centered on the condensing point P on the ceramic substrate 12 is reduced to about 5 mm, and in the range of 30 ° to 60 °, the droplet H The attachment range was certainly 5 mm or less. At approximately 45 °, the droplet H was attached only at the converging point P of the laser beam L.

In the above-described embodiment, since the cover member 38 of the laser scriber 10 mainly enhances the dust collecting effect, the cover member 38 may have another shape or may not necessarily be provided.

In the control device 60 of the above-described embodiment, for example, the period in which the converging point (scribe point) P of the laser beam L is moved in the + X direction during the rule-making process, that is, the ceramic substrate 12 is kept at -X During the period in which the gas is being moved in the direction, the electromagnetic on-off valve 48a is opened and the gas is controlled to be injected from the gas injection device 50a.
The electromagnetic on-off valve 48b may be opened alone or in addition to the opening of the electromagnetic on-off valve 48a to be opened so that the gas is injected from the gas injection device 50b or the gas injection devices 50a and 50b.

In the above-described embodiment, four gas injection devices 50a, 50b, 50c, and 50d are provided. However, one or two gas injection devices may be provided. For example, in the case of two, the converging point P of the laser beam L is in the + X direction and-
During the period of moving in the Y direction, the solenoid on-off valve 48
a is opened so that the gas is injected from the gas injection device 50a, and during the period when the focal point P of the laser beam L is moved in the −X direction and the + Y direction, the electromagnetic on-off valve 4
8c may be opened to control the gas to be injected from the gas injection device 50c. In short, during the period in which the focal point P of the laser beam L is moved in the + X direction, for example, the laser beam L needs to be injected from at least one of the gas injection devices 50a and 50b.

The above is merely an embodiment of the present invention, and the present invention can be variously modified without departing from the spirit thereof.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a main part of a laser scriber according to an embodiment of the present invention.

FIG. 2 is a plan view showing a cover member fixed to an injection cylinder for explaining a gas injection device provided in the laser scriber of the embodiment of FIG. 1;

FIG. 3 is a view for explaining the behavior of droplets during scribing in the laser scriber of the embodiment of FIG. 1;
It is sectional drawing which expands and shows an injection cylinder, a lens hood, a cover member, etc.

FIG. 4 is a view for explaining a concave hole formed in the ceramic substrate by irradiating a laser beam with the laser scriber of the embodiment of FIG. 1;

5 is a plan view showing a break ruled line formed by a series of a plurality of concave holes formed by laser light irradiation by the laser scriber of the embodiment of FIG. 1;

[Explanation of symbols]

10: Laser Scriber 12: Ceramic Substrate 26: CO ₂ Laser Oscillator, 30: Injection Tube, 32: Condensing Lens (Laser Irradiation Device) 36: Lens Hood 38: Cover Member 39: First Gas Supply Device 50a, 50b , 50c, 50d: Gas injection device

Claims (2)

[Claims] 1. A condenser lens facing a ceramic substrate, a lens hood having a through hole in a portion corresponding to an optical axis of the condenser lens to cover the condenser lens, and a ceramic hood through the through hole. A gas supply device for supplying gas into the lens hood to inject gas toward the lens hood,
By using a laser light irradiation device that focuses laser light on a ceramic substrate at a predetermined spot diameter and irradiating the laser light prior to the division of the ceramic substrate, a breaking ruled line composed of a series of a large number of concave holes A ceramic substrate dividing method using a laser of a type of forming on the ceramic substrate, by relatively moving the ceramic substrate and the irradiation point of the laser beam on the ceramic substrate, the breaking ruled line in one direction And a gas injection step of injecting a gas in a direction toward a laser beam between the through hole of the lens hood and the ceramic substrate during the crease step. Ceramic substrate splitting method using a laser. 2. A condensing lens fixed to an injection cylinder through which laser light passes so as to face the ceramic substrate, and a condensing lens having a through hole in a portion corresponding to the optical axis of the condensing lens. A lens hood provided on the injection cylinder so as to cover the ceramic substrate, and a gas supply device for supplying gas into the lens hood to inject gas toward the ceramic substrate through the through hole, Prior to the division, a laser beam is focused on the ceramic substrate with a predetermined spot diameter, so that a ceramic substrate dividing laser scriber of a type in which a break ruled line formed of a series of a large number of concave holes is formed on the ceramic substrate. A cover member provided on the injection cylinder to cover a space between the lens hood and the substrate; and a cover member provided on the cover member, The direction toward the laser beam and a gas injection device for injecting gas, a ceramic substrate dividing laser scriber, characterized in that it comprises between the through-hole of the de and the ceramic substrate.