JPH10277768A - Laser beam machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the laser beam machine having high machining precision and not necessitating to change all bend mirrors. SOLUTION: The excimer laser beam 12 emitted from an excimer laser beam source 11 is made incident on a homogenizer 14 via an expander 13 and divide into plural excimer laser beams, and these divided excimer laser beam are respectively condensed. The excimer laser beam emitted from the homogenizer 14 is formed into the shape corresponding to a nozzle machining pattern with a mask 15 and reflected with the bend mirror 17 via a field lens 106, and the image is formed on a nozzle plate 19 with an image forming optical system 18. Since no bend mirror is provided between the homogenizer 14 and the mask 15, the machining precision due to the deterioration of the bend mirror is not reduced and moreover the change of the bend mirror also is not necessitated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus, and more particularly, to a laser processing apparatus for processing a nozzle plate of a nozzle plate used in an ink jet recording head which performs recording by discharging ink droplets onto a recording medium. It relates to a processing device.

[0002]

2. Description of the Related Art Heretofore, as the above-mentioned laser processing apparatus, for example, an apparatus which forms a nozzle on a nozzle plate using an ablation phenomenon of an excimer laser beam is known. FIG. 3 is an explanatory diagram illustrating the overall configuration of the laser processing apparatus. FIG. 4A is a diagram illustrating a state in which an excimer laser beam is irradiated on a nozzle plate, and FIG. 4B is a diagram illustrating a nozzle plate on which nozzles are formed.

In FIG. 3, an excimer laser beam 31 emitted from an excimer laser light source 30 is reflected by a first bend mirror 40 and is expanded by a beam expander 32.
Is incident on. The beam expander 32 expands and outputs the incident excimer laser beam 31. The emitted excimer laser beam 31 is applied to the homogenizer 5.
0, and the homogenizer 50 converts the incident excimer laser beam 31 into a plurality of excimer laser beams 31.
And the condensed excimer laser beams 31 are respectively emitted.

[0004] The emitted excimer laser beam 31 is supplied to a second bend mirror 41 and a third bend mirror 42.
The light is reflected by the fourth bend mirror 43 and is incident on the mask 60. The mask 60 forms the incident excimer laser beam 31 into a pattern corresponding to the shape to be processed, that is, the nozzle shape, and emits the same. The emitted excimer laser beam 31 is incident on the field lens 61, and the field lens 61 expands and emits the incident excimer laser beam 31.

The emitted excimer laser beam 31
Is reflected by the fifth bend mirror 44, the sixth bend mirror 45, and the seventh bend mirror 46, and is incident on the imaging optical system 62. The imaging optical system 62 condenses the incident excimer laser beam 31 and forms an image on the nozzle plate 70 as shown in FIG. Then, the portion of the nozzle plate 70 irradiated with the excimer laser beam 31 is processed by the ablation phenomenon of the excimer laser beam 31 to form the nozzle 71 as shown in FIG. Here, the ablation phenomenon is
When a material is irradiated with an excimer laser beam having a high energy density, it means a phenomenon in which a material in a portion irradiated with the beam is photolyzed and scattered.

[0006]

SUMMARY OF THE INVENTION The present inventor has noticed that the laser processing apparatus having the above-described structure reduces the processing accuracy of the nozzle while the processing of the nozzle is repeated. Then, as a result of investigating the cause, the second bend mirror 4
It was found that the cause was deterioration of the first to fourth bend mirrors 43. That is, in the early stage when the use time of the bend mirror is short, the beam reflectance from one end 60a to the other end 60b of the mask 60 is 100% as shown in FIG. The energy density of the excimer laser beam 31 is uniform, but as the excimer laser beam 31 is repeatedly reflected, as shown in FIG. Is smaller, so that the energy density is lower in the portion excluding both ends than in both ends of the mask 60. Therefore, in the above-mentioned conventional one, there is a problem that the processing accuracy is reduced due to the deterioration of the bend mirror, and that all the bend mirrors must be periodically replaced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a laser processing apparatus which does not reduce the processing accuracy due to the deterioration of the reflection means and does not need to periodically replace the reflection means.

[0008]

According to the present invention, in order to achieve the above object, according to the first aspect of the present invention, a laser emission source and an emission light emitted from the laser emission source are divided, and A homogenizer for condensing each of the divided light, and a mask for irradiating the light emitted from the homogenizer into a pattern of a predetermined shape and irradiating the light on the workpiece; and forming the predetermined shape on the workpiece. In a laser processing apparatus for processing a pattern, at least between the homogenizer and the mask, a technical means is employed in which there is no reflection means for reflecting light emitted from the homogenizer and guiding the light to the mask. I do.

According to a second aspect of the present invention, in the laser processing apparatus according to the first aspect, light emitted from the laser emission source is reflected between the laser emission source and the homogenizer to reflect the light emitted from the laser emission source. A technical means is employed in which no reflection means for guiding to the homogenizer is provided.

According to a third aspect of the present invention, in the laser processing apparatus according to the first or second aspect, the workpiece is a nozzle plate on which a nozzle for ejecting ink is formed, and the workpiece is formed from the mask. The applied light employs a technical means of processing a nozzle pattern of a predetermined shape on the nozzle plate.

[0011]

According to the first to third aspects of the present invention, at least between the homogenizer and the mask, there is no reflecting means for reflecting the light emitted from the homogenizer and guiding the light to the mask. There is no possibility that the distribution of the energy density of the laser on the mask due to the deterioration of the mirror becomes non-uniform. Therefore, unlike the related art, there is no possibility that the processing accuracy is reduced, and it is not necessary to periodically replace all of the reflection means. That is, as described in the embodiments of the invention described later, among all the bend mirrors, the deterioration of the bend mirror installed between the homogenizer and the mask causes the energy density of the excimer laser beam on the mask to be reduced. Since it was found that this was a major cause of uniformity, by adopting a structure without a bend mirror that caused the deterioration, it was possible to eliminate the reduction in processing accuracy due to the deterioration of the bend mirror, and to reduce all bend mirrors. No need to replace.

In particular, in the second aspect of the present invention, no reflection means is provided between the laser light source and the homogenizer to reflect the light emitted from the laser light source and guide the light to the homogenizer. Since the energy density of the excimer laser beam on the mask can be made more uniform, the processing accuracy can be further improved.

The technical means according to claim 1 or 2 is a nozzle plate in which the workpiece is formed with a nozzle for ejecting ink, as in the invention according to claim 3. The light emitted from the mask is suitably used in a laser processing apparatus for processing a nozzle pattern of a predetermined shape on the nozzle plate. That is, for example, in an ink jet recording apparatus that performs recording by discharging ink droplets from a nozzle onto recording paper, a nozzle that processes a nozzle plate used for a recording head requires a processing accuracy of a micron order or a submicron order. That is because

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. First, the results of research conducted by the present inventors on the cause of deterioration of the bend mirror will be described. As a result of examining the deterioration state of each of the first to seventh bend mirrors 40 to 46 shown in FIG.
The second bend mirror 41, the third bend mirror 42 and the fourth bend mirror 42 existing between the homogenizer 50 and the mask 60.
It was found that the three bend mirrors of the bend mirror 43 deteriorated more than the other bend mirrors.

Therefore, the present inventor measured the energy density of the excimer laser beam 31 on the three bend mirrors in order to investigate the cause of the deterioration of the three bend mirrors. Here, among the three bend mirrors, the energy density on the third bend mirror 42 will be described as a representative. FIG. 2 is an explanatory diagram showing an energy distribution until the excimer laser beam 31 emitted from the homogenizer 50 reaches the mask 60. In practice, the excimer laser beam 31 emitted from the homogenizer 50 is reflected by the three bend mirrors and reaches the mask 60. However, in order to make the description easy to understand, FIG. Mask 6
0 is set on a straight line.

As shown in FIG. 2, the excimer laser beams emitted from the lenses 51a to 51d of the split lens 51 constituting the homogenizer 50 are respectively condensed by lenses 52 and reflected by the three bend mirrors. To reach the mask 60. In order to make the energy density of the excimer laser beam 31 applied to the nozzle processing position of the nozzle plate 70 uniform and to improve the processing accuracy of the nozzle 71, the energy density of the excimer laser beam 31 applied to the mask 60 is uniform. Need to be. Therefore, the homogenizer 50 and the mask 60
The excimer laser beam 31 emitted from the homogenizer 50 is set at a distance where the energy density of the excimer laser beam 31 becomes uniform from one end to the other end on the mask 60.

However, since the third bend mirror 42 is provided between the homogenizer 50 and the mask 60,
On the third bend mirror 42, a portion B where the excimer laser beam emitted from the lens 51d and collected by the lens 52 intersects with the excimer laser beam emitted from the lens 52c and collected by the lens 52 intersects. A portion A not to be formed is formed. On the third bend mirror 42, the excimer laser beam emitted from the lens 51a and collected by the lens 52 is connected to the lens 52b.
Are formed, and a portion D where the excimer laser beam converged by the lens 52 intersects and a portion E which does not intersect are formed. Further, on the third bend mirror 42, a portion C where the excimer laser beams emitted from the lenses 51b and 51c and condensed by the lens 52 intersect is formed.

That is, one end 4 on the third bend mirror 42
From 2a to the other end 42b, the energy density of the portion excluding both ends is higher than the energy density of both ends. Due to the non-uniformity of the energy density, the excimer laser of the third bend mirror 42 It was found that a portion of the reflective film having a high energy density was decomposed by the ablation phenomenon of the excimer laser beam, and as shown in FIG.

The present inventor has invented a laser processing apparatus according to the embodiment of the present invention shown in FIG. Laser processing equipment 1
Reference numeral 0 denotes an excimer laser light source 11 serving as a laser light emitting source of the present invention for emitting an excimer laser beam, and an excimer laser beam 12 emitted from the excimer laser light source 11.
Expander 13 and expander 13
A homogenizer 14 for dividing the excimer laser beam 12 emitted from the laser beam and condensing the divided excimer laser beams, and a homogenizer 14
15. A mask 15 for forming an excimer laser beam emitted from the mask into a workpiece, that is, a pattern having a shape corresponding to the shape of a nozzle formed on a nozzle plate 19, and a field for expanding the excimer laser beam emitted from the mask 15. The lens 16 and the field lens 16
And a plurality of lenses for imaging the excimer laser beam reflected by the bend mirror 17 on the nozzle plate 19. And an optical system 18.

When the excimer laser light source 11 is activated in the laser processing apparatus 10 having the above configuration, an excimer laser beam 12 is emitted from the excimer laser light source 11, and the emitted excimer laser beam 12 is transmitted to a beam expander 13. Incident. Subsequently, the beam expander 13 outputs the incident excimer laser beam 1
2, and the emitted excimer laser beam is incident on the homogenizer 14. Subsequently, the homogenizer 14 divides the incident excimer laser beam into a plurality of excimer laser beams, and collects and emits the divided excimer laser beams.

Subsequently, the excimer laser beam emitted from the homogenizer 14 is incident on a mask 15. The mask 15 forms the incident excimer laser beam into a pattern corresponding to the nozzle shape and emits the same. Subsequently, the excimer laser beam emitted from the mask 15 is incident on a field lens 16, and the field lens 16 converts the incident excimer laser beam into a parallel beam and emits the same. Subsequently, the excimer laser beam emitted from the field lens 16 is incident on the imaging optical system 18, and the imaging optical system 18 processes the incident excimer laser beam as shown in FIG. Table 2
An image is formed on the nozzle plate 70 set to 0. Then, the portion of the nozzle plate 70 irradiated with the excimer laser beam is processed by the ablation phenomenon of the excimer laser beam, and the nozzle 71 is formed as shown in FIG.

As described above, according to the laser processing apparatus 10 of the first embodiment, between the excimer laser light source 11 and the mask 15, particularly, the homogenizer 14 and the mask 1
Since no bend mirror is provided between the excimer laser beam and the mask 5, there is no possibility that the energy density of the excimer laser beam on the mask 15 becomes non-uniform due to deterioration of the bend mirror. Therefore, the processing accuracy of the nozzles of the nozzle plate 19 can be improved, and it is not necessary to replace all the deteriorated bend mirrors.

It is to be noted that a conventional arrangement in which a bend mirror is provided between the homogenizer 14 and the mask 15 is not desirable because deterioration of the bend mirror greatly affects the processing accuracy. However, the excimer laser light source 11 and the expander Even if a bend mirror is provided between the excimer laser light source 1 and the
A bend mirror may be provided between 1 and the expander 13 to shorten the distance from the excimer laser light source 11 to the mask 15.

In FIG. 1, the bend mirror 17 is not provided, and the excimer laser
May be arranged in a straight line. Further, in the above-described embodiment, the laser processing apparatus of the present invention for processing a nozzle plate has been described as a representative example. The present invention can also be applied to an exposing machine for forming a high-precision resist pattern.

[0025]

As described above, according to the laser processing apparatus of the present invention, there is realized a laser processing apparatus which does not reduce the processing accuracy due to the deterioration of the reflection means and which does not require periodic replacement of the reflection means. can do.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a laser processing apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an energy distribution until an excimer laser beam 31 emitted from a homogenizer 50 reaches a mask 60.

FIG. 3 is an explanatory view of a conventional laser processing apparatus.

FIG. 4A is a diagram illustrating a state in which a nozzle plate is irradiated with an excimer laser beam, and FIG.
It is explanatory drawing of the nozzle plate in which the nozzle was formed.

FIG. 5A is an explanatory diagram showing a reflectance and an energy density of an excimer laser beam on a mask 60 in an initial case in which the use time of a bend mirror is short,
(B) is an explanatory diagram showing the reflectivity and energy density of the excimer laser beam on the mask 60 of the degraded bend mirror.

[Explanation of symbols]

 Reference Signs List 10 excimer laser light source 12 excimer laser beam 13 expander 14 homogenizer 15 mask 16 field lens 19 nozzle plate 20 processing table

Claims (3)

[Claims] 1. A laser light source, a homogenizer for dividing light emitted from the laser light source, and condensing each of the divided light, and a light beam emitted from the homogenizer having a predetermined shape. And a mask that irradiates the workpiece with the mask and irradiates the workpiece with the mask. The laser processing apparatus processes the pattern having the predetermined shape on the workpiece. At least between the homogenizer and the mask, the homogenizer is provided. A laser processing apparatus provided with no reflecting means for reflecting the light emitted from the mask and guiding the light to the mask. 2. A reflection means for reflecting light emitted from the laser light source and guiding the light to the homogenizer is not provided between the laser light source and the homogenizer. The laser processing apparatus according to item 1. 3. The object to be processed is a nozzle plate on which nozzles for ejecting ink are formed, and the light emitted from the mask is for processing a nozzle pattern of a predetermined shape on the nozzle plate. The laser processing apparatus according to claim 1 or 2, wherein: