JPH11267866A - Laser processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser processing method, by which the effect due to the shock and vibration of a laser light is eliminated so as to carry out precise processing, and adhesion of debris to the reverse face of a processing member is prevented so as to laser process a through hole simply. SOLUTION: A fiber type member 21 with good permeability is put on a processing stage 22, and a processing member 20 is arranged thereon. The processing member 20 is adsorbed and fixed via the fiber type member 21 by being sucked from a permeable hole 31 arranged to the processing stage 22 by means of a vacuum pump 23. When processing is performed by the irradiation of a pulse laser light, the fiber type member 21 functions as a buffer material to restrain the shock and vibration. The debris generated at that time, is oxidized and blown off by an assist gas 32. After the penetration of the processing member 20, the debris is adsorbed to the fiber type member 21 by sucking, and is not adhered to the reverse face of the processing member 20. Further, since the processing stage is not broken, the next step can be started by only changing the fiber type member 21 after processing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of applying a pulse laser to at least a processing member which requires formation of a through hole, such as a component of a liquid jet recording head for performing recording on a recording medium by flying droplets. The present invention relates to a laser processing method for performing a drilling process by using the laser processing.

[0002]

2. Description of the Related Art In recent years, with the progress of laser processing technology,
Laser processing has been applied to various processing members. As one of them, a fine flow path shape for a plastic flow path member of a liquid jet recording head, a through-hole serving as a liquid discharge section, and the like are formed.

FIG. 5 is an explanatory diagram of ablation processing using a laser beam. In the drawing, 41 is a projection mask, 42 is a processing member, and 43 is a processing stage. As shown in FIG. 5A, when the processing member 42 is placed on the processing stage and the processing member 42 is irradiated with the ultraviolet laser light via the projection mask 41, the energy of the irradiated ultraviolet laser light is reduced. Absorbed at a slight depth of 1 μm or less from the surface. The high-molecular substance breaks a chemical bond by the absorbed energy (FIG. 5B), and is converted into a monomer and a gas. The gasified monomer generated by the breaking of the chemical bond is scattered, and the processing member 42 can be processed according to the shape irradiated with the ultraviolet laser as shown in FIG. 5C.

[0004] In such laser processing, there is a problem that a debris in which the polymer substance of the processing member 42 is carbonized during the processing and adheres to the processing member 42. In order to prevent such adhesion of debris, for example, an assist gas such as O ₂ gas is blown to oxidize the debris,
A method of blowing away has been proposed. For example, JP-A-8-1
In Japanese Patent No. 87586, the debris is removed by blowing and sucking O ₂ gas onto the processing member. According to this method, debris can be removed satisfactorily in processing at a depth that does not allow the processed member to penetrate. However, when the through holes are formed, the debris goes around and adheres to the back surface of the processed member. Therefore, it was not possible to prevent debris from adhering to the back surface of the processed member only by blowing the assist gas.

[0005] In the above-described laser processing, the processing member 42 receives a large impact force when irradiating a laser beam, and the processing member 42 vibrates during the processing, which may cause a variation in the processing shape. there were. Further, when a through-hole is formed in the processing member 42, after the processing member 42 penetrates, the processing stage 43 on which the processing member 42 is mounted is irradiated with laser light, and the surface of the metal processing stage 43 is simultaneously irradiated. I will process it. For this reason, there is a problem that the processing stage 43 is damaged, the adhesion to the processing member is gradually reduced, and play is generated, and the processing accuracy is reduced. In addition, there is a problem that the rebound when the processing stage 43 is processed adheres to the processing member 42, and the processing shape is deteriorated, thereby affecting the quality.

[0006] The above-mentioned Japanese Patent Application Laid-Open No. 8-187586 describes a method of processing a workpiece by fixing the workpiece by vacuum attraction of a processing stage. In this method, since the processing member can be satisfactorily fixed to the processing stage, displacement or the like is less likely to occur with respect to impact or vibration due to laser light irradiation, and good processing accuracy can be obtained. However, the effect of processing the processing stage cannot be excluded. Further, the attachment of debris to the back surface of the processed member could not be avoided.

[0007] As another method, there is a method in which a contact liquid such as water or alcohol is applied to the surface of the processing stage to bring the processing member into close contact. In this method, the contact liquid absorbs shocks and vibrations caused by laser light irradiation. However, when a through hole is formed, the contact liquid is scattered by irradiating the contact liquid with laser light after the hole is penetrated, thereby preventing the vibration of the processing member and the adhesion of the debris to the back surface of the processing member. I can't.

As another method, for example, Japanese Patent Laid-Open No.
As described in Japanese Patent Application Laid-Open No. 183010, a method of applying a wax to the surface of a processing stage to suppress vibration during processing and bringing a processing member into close contact with the processing stage has been considered. In this method, even if a laser beam is applied to the wax after the formation of the through hole, the wax around the through hole is not affected, and the work member can be fixed to the work stage satisfactorily and the back surface of the work member can be fixed. Can be prevented from adhering. However, the wax after forming the through-hole has been modified by laser at least in the portion of the through-hole, and after processing the processed member, the wax attached to the back surface of the processed member and the surface of the processing stage is heated, for example. It is necessary to wash and remove using a solvent or the like. For this reason, there is a problem in that a large amount of setup time is required until the processing of the next processing member is started. There is also a problem that a step of cleaning wax attached to the processed member is required.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and it is possible to eliminate the influence of the impact or vibration of a laser beam and to perform a precise machining, and at the same time, to form a machining member. It is an object of the present invention to provide a laser processing method that can prevent debris from adhering to the back surface and can easily laser-process a through hole.

[0010]

According to the present invention, a processing member is mounted on a processing stage via a fibrous body, and a through hole is formed by laser processing. The impact and vibration when the laser beam is applied to the processing member is reduced by the fibrous body, and the processing accuracy can be improved. In addition, even after the through hole is formed, the back surface of the processed member is still covered with the fibrous body, and since the fibrous body sucks and holds the debris, the debris is prevented from adhering to the back surface of the processed member. be able to. Further, an inexpensive fibrous body such as paper can be used as the fibrous body, and replacement after processing is easy. Therefore, it is not necessary to clean and wash the surface of the processing stage after processing as in the related art, and the processing can be simplified, and the processing can be performed simply and at low cost. Furthermore, by using a fibrous body having good air permeability, the processing member can be suction-fixed to the processing stage, and favorable processing can be performed.

[0011]

FIG. 1 is a schematic diagram showing an example of a laser processing apparatus for realizing an embodiment of a laser processing method according to the present invention. FIG. 2 is an enlarged plan view showing an example of a processing stage. FIG. 3 is an enlarged sectional view showing an example of the processing stage. In the figure, 11 is a laser generator, 12
14 to 14 are mirrors, 15 is aperture, 16 is shutter,
17 is a mask, 18 is a lens, 19 is a focus driving device,
20 is a processing member, 21 is a fibrous body, 22 is a processing stage, 23 is a vacuum pump, 24 is a processing stage drive,
25 is a monitor, 26 is a measurement camera, 27 is a focus driving device, 28 is a feedback control panel, 29 is a laser generation control panel, 31 is a vent, and 32 is an assist gas.

The laser generator 11 emits an ultraviolet pulse laser beam such as an excimer laser. Excimer laser light emitted from the laser generator 11 is reflected by mirrors 12 and 13, passes through a stop 15, and reflects only laser light in an irradiation area set by a mask 17 with a shutter 16 by a mirror 14. Lens 18
The light is focused. At this time, the lens 18 is driven by the focus driving device 19 and focused so that the laser light is focused on the processing surface of the processing member 20 on the processing stage 22. In this example, the optical path of the laser beam is guided onto the processing member 20 by the three mirrors 12 to 14, but the number of mirrors is not limited to three depending on the device configuration, and may be appropriately used, and may be configured without using a mirror. . Also, the shutter 16
May be omitted if unnecessary.

A processing member 20 is mounted on the processing stage 22 via a fibrous body 21 so that the surface of the flow path forming member 4 faces the lens 18 side. The fibrous body 21
It is a fibrous member with good air permeability. As a specific example, a paper having a uniform thickness of about 100 μm and good air permeability can be used. 2 and 3 are shown in FIG.
As shown in (1), one or a plurality of ventilation holes 31 are provided on the surface thereof, and communicate with the vacuum pump 23 via an internal space. When the vacuum pump 23 is operated and sucked, the space inside the processing stage 22 becomes a negative pressure, and the fibrous body 21 is sucked through the vent hole 31.
Further, since the fibrous body 21 is a member having good air permeability, the processed member 20 is sucked through the fibrous body 21, and the processed member 20 can be suction-fixed to the processing stage 22 via the fibrous body 21. it can.

As shown in FIG. 3, O ₂ gas is jetted from above the processing stage 22 as an assist gas 32 during processing. This oxidizes and scatters the debris generated when the processing is performed by irradiating the laser beam, thereby preventing the debris from adhering to the surface of the processing member 20.

The processing stage 22 has a processing stage driving device 24 at a position of the measuring camera 26 on the monitor 25 such that the processing surface of the processing member 20 is perpendicular to the laser beam.
Are driven in the rotation directions θ1, θ2, and θ3 to adjust. The focus of the measuring camera 26 is adjusted by the focus driving device 27. Thereafter, the height between the processing stage 22 and the processing surface of the processing member 20 is measured. The processing stage drive device 24 is driven in the Y direction to move the processing member 20 to the processing position, and performs processing by laser. By shaking the beam of the excimer laser light, the surface of the processing member 20 is processed into a shape corresponding to the opening shape of the mask 17.
The processing depth of the processing member 20 can be controlled by the intensity and irradiation time of the laser beam.
Controls the generation of laser light according to the set value.

A case where a through hole is formed in the processing member 20 using such a laser processing apparatus will be described. FIG.
FIG. 2 is an explanatory diagram of an example of a processing mode in one embodiment of the laser processing method of the present invention. As described above, the fibrous body 21 made of paper or the like is laid on the processing stage 22, and the processing member 20 is placed thereon. By operating the vacuum pump 23 and sucking air, air is sucked from the air holes 31 provided in the processing stage 22. Since the fibrous body 21 laid thereon has good air permeability, the fibrous body Air is also sucked in through 21. Therefore, when the processing member 20 is placed on the fibrous body 21, the processing member 20 is sucked through the fibrous body 21 and is fixed to the processing stage 22.

In a state where the processing member 20 is fixed by suction to the processing stage 22 via the fibrous body 21, the laser beam whose energy and irradiation time are controlled by the laser generation control panel 29 is applied to the mask 17. Irradiate the processed member 20 through. The portion irradiated with the laser beam is subjected to ablation processing as shown in FIG. 5 to form a concave portion. At this time, the assist gas 32 is applied to the laser irradiation portion of the processing member 20.
While spraying. As a result, debris generated by the ablation process is oxidized by the assist gas 32 and scatters. As a result, the debris does not adhere to the surface of the processing member 20.

Further, the fibrous body 21 also has a function of a cushioning material, so that the fibrous body 21 can absorb the impact force when the processing member 20 is irradiated with the laser beam. Therefore, vibration of the processing member 20 can be suppressed, and accurate processing can be performed.

As the processing is further continued, the depth of the concave portion gradually increases and finally penetrates the back surface of the processed member 20. In this way, a through hole can be formed.
Usually, since the processing depth is determined in consideration of the error in the thickness of the processing member 20, even after the through-hole is formed in the processing member 20, some laser light irradiation is performed. for that reason,
As shown in FIG. 4, the fibrous body 21 is also processed by the laser beam. However, since the fibrous body 21 is not processed except for the portion irradiated with the laser beam, the fibrous body 2 is not processed.
The state in which 1 covers the back surface of the processing member 20 is maintained, and the attachment of debris to the back surface of the processing member 20 can be prevented. Further, since the suction is performed by the suction pump 23 for fixing, the generated debris is absorbed by the fibrous body 21. Therefore, it is possible to further prevent the debris from adhering to the back surface of the processing member 20. At this time, the ventilation holes 31
Even if it is not in the vicinity, the suction force in the processed portion acts due to the flow of air in the fibrous body 21, so that debris can be absorbed in an area larger than the vent hole 31 and can be adsorbed to the fibrous body.

Although the laser beam is irradiated for a while after the through-hole is formed in the processing member 20 as described above,
During this time, only the fibrous body 21 is processed, and the processing stage 22 is hardly damaged. Therefore, there is no occurrence of rattling or positional deviation of the processing member 20 due to damage to the processing stage.

After the processing, the suction by the vacuum pump 23 is stopped, and the processed member 20 is transported to the next step. Since a material such as a wax that easily adheres to the processing member 20 as in the related art is not used at the time of processing, there is no need to clean or wash the processing member 20 after processing. Further, the fibrous body 21 left after the processing can be easily replaced, and the state before the processing can be returned by replacing the fibrous body 21. Of course, depending on the state of the fibrous body 21 after the processing, the fibrous body 21 may be used as it is for the next processing of the processing member 20. It is not necessary to clean and wash the processing stage 22 before the next processing. Therefore, the time required for preparation for processing can be reduced, and the time required for laser processing can be reduced as a whole. Further, the fibrous body 21 can be made of, for example, paper as described above, and is very inexpensive, so that the processing cost can be reduced.

The laser processing method of the present invention can be applied to any processing member that requires drilling of all through holes. For example, in a liquid jet recording head, it is necessary to form a discharge unit that opens to the outside in order to jet the liquid held inside. At this time, depending on the configuration of the liquid jet recording head, the ejection section is formed as a through hole. In order to cope with the recent increase in recording density, the formation of the ejection portion requires high accuracy. There is also an urgent need to lower prices. By using the laser processing method of the present invention, accurate processing can be realized at low cost, and a high quality liquid value ejection recording head can be obtained.

[0023]

As is apparent from the above description, according to the present invention, a fibrous body is mounted on a processing stage, and a processing member is set thereon to perform laser processing of a through hole. The fiber state reduces the impact and vibration caused by the laser beam during processing, so that stable and accurate processing can be performed. Further, it is possible to prevent the debris generated after penetrating the processing member from adhering to the back surface of the processing member. Furthermore, the fibrous body is easily replaceable, and does not require cleaning or cleaning of the processing stage surface and the processing member. further,
The processing stage can be prevented from being damaged, and the processing member can be prevented from rattling or being displaced due to the damage on the processing stage, so that accurate processing can be performed.

Further, by using a fibrous body made of a material having good air permeability and sucking it from the inner side of the processing stage, the processing member can be surely fixed by suction through the fibrous body and can be processed. The debris generated after penetrating the member can be absorbed by the fibrous body by suction, and the debris can be prevented from adhering to the back surface of the processed member.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an example of a laser processing apparatus that realizes an embodiment of a laser processing method according to the present invention.

FIG. 2 is an enlarged plan view illustrating an example of a processing stage in an example of a laser processing apparatus that realizes an embodiment of the laser processing method of the present invention.

FIG. 3 is an enlarged cross-sectional view illustrating an example of a processing stage in an example of a laser processing apparatus that realizes an embodiment of the laser processing method of the present invention.

FIG. 4 is an explanatory diagram of an example of a processing mode according to an embodiment of the laser processing method of the present invention.

FIG. 5 is an explanatory diagram of ablation processing using a laser beam.

[Description of Signs] 11 ... Laser generator, 12-14 ... Mirror, 15 ... Aperture, 16 ... Shutter, 17 ... Mask, 18 ... Lens,
19: Focus driving device, 20: Work member, 21: Fibrous body, 22: Processing stage, 23: Vacuum pump, 24: Processing stage drive device, 25: Monitor, 26: Measurement camera, 27: Focus drive device , 28: feedback control panel, 29: laser generation control panel, 31: vent hole, 32: assist gas.

Claims (5)

[Claims] 1. A laser processing method for performing drilling using a pulse laser on at least a processing member that requires formation of a through hole, wherein the processing member is installed on a processing stage via a fibrous body, and A laser processing method, wherein a hole is formed by a laser to form the through hole. 2. The processing stage is provided with a ventilation hole which is opened on a surface on which the processing member is installed, and the fibrous body is a member having good air permeability, and suction from the ventilation hole is provided. The laser processing method according to claim 1, wherein the processing member is fixed via the fibrous body by force. 3. The laser processing method according to claim 1, wherein the pulse laser is an excimer laser. 4. The laser processing method according to claim 1, wherein the fibrous body is paper. 5. The liquid ejecting recording head according to claim 1, wherein the processing member is a constituent member of a liquid jet recording head, and the through-hole is a liquid discharge unit. Laser processing method.