JPH0910976A - Laser beam machine - Google Patents

Abstract

PURPOSE: To provide a laser beam machine which executes laser processing with a low cost and a high grade by efficiently executing processing of the inside of grooves and executing processing without affecting the other parts. CONSTITUTION: The laser beam processing of the electrodes 9 formed within the grooves of a piezoelectric ceramic substrate 1 is continued by scanning these electrodes at a high speed with a YAG laser beam 10 by oscillation of two sets of scanning mirrors 12, 13 when the incident angle in the incident route of the YAG laser beam 10 is within a prescribed angle range. The position of the piezoelectric ceramic substrate 1 is moved by a precision table 18 to adjust the incident angle to the regulated angle range if the incident angle of the YAG laser beam 10 deviates from the prescribed angle range. The laser beam processing is thereafter continued by the oscillation of the scanning mirror 12.

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 irradiating a high-energy beam to the inside of a groove of a workpiece having a plurality of grooves formed therein. Is.

[0002]

2. Description of the Related Art In recent years, among the non-impact type recording apparatuses, which have replaced the existing impact type recording apparatuses and are greatly expanding the market, the principle is the simplest, and multi-gradation and colorization are realized. As easy as
An inkjet type recording apparatus can be used. Inkjet printers are attracting attention because they have advantages such as high-speed printing, low noise, high printing quality, and a relatively simple structure and low manufacturing cost.

A plurality of methods have been proposed for ink jet heads used in ink jet printers. Among them, a drop type ejecting only ink droplets used for recording.
The on-demand type is rapidly spreading due to its good injection efficiency and low running cost.

As one example, a piezoelectric ink jet head has been proposed. This is because the plurality of ink chamber grooves are formed in the piezoelectric body, and the volume of the ink chamber can be changed by the dimensional displacement of the piezoelectric body when a voltage pulse is applied to the piezoelectric body. Thereby, when the volume is reduced, the ink in the ink chamber is ejected from the nozzle portion connected to the ink chamber, and when the volume is increased, the ink is introduced into the ink chamber. Then, by ejecting ink from the ink chamber at a predetermined position, it is possible to form a desired character or image.

An example of such a piezoelectric ink jet head will be described with reference to FIGS. The head described here is of a shear mode type.

In the ink jet head, grooves are formed in parallel with each other by dicing or the like on a piezoelectric ceramic substrate 51 which is a piezoelectric body, and a large number of ink chambers 52 are formed. A nozzle plate 53 is connected to one end of the ink chamber 52. Incidentally, as shown in FIG. 6A, the piezoelectric side wall 57 forming the ink chamber 52 is formed by two piezoelectric side walls having different polarization directions 58,
An electrode 59 is formed on the surface of the piezoelectric side wall 57. Further, the nozzle plate 53 is provided at one end of the ink chamber 52.
And nozzles 54 are formed in the nozzle plate 53. Further, the upper portion of the piezoelectric ceramic substrate 51 in which the ink chamber 52 is formed is covered with an upper lid 56 having an ink supply port 55. Ink chamber 52
Is connected to an ink storage tank (not shown) via the ink supply port 55. With such a configuration, the sectional shape of the ink chamber 52 becomes a rectangle surrounded by the piezoelectric side wall 57 and the upper lid 56.

In the conventional ink jet head having such a structure, when a voltage pulse is applied to the electrode 59, the piezoelectric side wall 57 is sheared and deformed inward as shown in FIG. Is set as a positive pressure, and ink droplets are ejected from the nozzle 54 on the nozzle plate 53 connected to one end of the ink chamber 52.

When the application of the voltage pulse to the electrode 59 is cut off, the piezoelectric side wall 57 returns to the state shown in FIG. 6 (a),
The ink is supplied from the ink supply port 55 to the ink chamber 52 by the negative pressure at that time.

In the ink jet head having such a structure, there are a large number of ink chambers 52, and it is necessary to selectively eject ink droplets from the nozzle 54 at the tip of each ink chamber. Therefore, the electrodes 59 formed on the surface of the piezoelectric side wall 57 of each ink chamber 52 need to be electrically independent from each other.

As a method for forming the electrode 59,
It is common to use a metal thin film forming means such as vacuum deposition, sputtering, or plating. However, it is difficult to efficiently and stably form the electrically independent electrodes by the means as described above. Therefore, once an electrode is formed on the entire surface of the piezoelectric body by the above-described means, and then a part of the electrode is selectively removed to arbitrarily form an electrically discontinuous portion. A method is being considered.

As a method for removing a part of the electrodes, mechanical processing such as dicing processing has been considered in the past, and recently, a laser processing method that enables non-contact processing at higher speed has been considered. .

An example of a conventional method for manufacturing an ink jet head including such a laser processing step is shown in FIGS.
Explanation will be made using 0.

The laser light 61 emitted from the laser oscillator 60 is redirected by a reflecting mirror 62 arranged on its optical path, and then enters a condenser lens 63 arranged below the reflecting mirror 62. The laser light 61 passes through the condenser lens 63.
Is condensed by the condenser lens 63 to form a focal point 64 at a position of a predetermined focal length F.

A piezoelectric ceramic substrate 51, which is a workpiece.
Is mounted on the precision table 65 and is arranged below the condenser lens 63. Here, the positional relationship is such that the focal point 64 of the laser beam 61 is formed in the vicinity of the electrode 59 formed on the bottom surface of the groove, which is the ink chamber 52 that is the processed portion. Since the power density is high at the focus of the laser light 61, the electrode 59 irradiated with the laser light 61
Are heated in a very short time and lead to evaporation.

In the laser processing method of FIG. 7, the precision table 65 is driven and controlled, and the piezoelectric ceramic substrate 51 is controlled.
The electrode 59 can be removed with high accuracy by moving the electrode relative to the focal point 64 in the front-back and left-right directions. By the above processing, the electrode 59 is removed from the surface of the piezoelectric ceramic substrate 51, and an electrically discontinuous portion can be formed on the surface of the piezoelectric ceramic substrate 51.

As another example, the workpiece is moved in one direction (left and right direction in the figure) by driving the precision table, and the other direction (front and rear direction in the figure) is set by a set of scanning mirrors. FIG. 8 shows a laser processing method in which light scanning is performed in another direction (front-back direction in the figure).

The laser light 61 emitted from the laser oscillator 60 is scanned by the scanning mirror 6 arranged on the optical path.
After being incident on 6, the light is changed in direction and is incident on the f · θ lens 67 arranged below the scanning mirror 66.
A galvanometer 68 is provided at one end of the scanning mirror 66.
Are connected, and the scanning mirror 66 is swung at a high speed by these configurations. Then, by swinging the scanning mirror 66, the machining in the direction in which the groove is formed is processed without moving the precision table, and when processing the next groove, a predetermined pitch amount is moved by driving the precision table. Then, the processing is continued.

As yet another example, as shown in FIG. 9, there is a method of scanning the laser beam forward, backward, leftward and rightward by using two or more sets of scanning mirrors without using a precision table.

[0019]

However, the conventional laser processing method described above has the following problems.

Generally, in an ink jet head,
It has dozens of grooves. Therefore, for example, in the above-mentioned conventional method, in the method of moving the workpiece only by driving the precision table, there is a limit to the speeding up of the processing because of the control of the precision table. Further, the same applies to the processing using a combination of a precision table and one set of scanning mirrors.

On the other hand, in the method of scanning the laser beam using two or more sets of scanning mirrors without using the precision table, high-speed processing can be realized. However, this method has a problem as shown in FIG. 10 due to the configuration of the device.

That is, as shown in FIG.
When 1 is scanned at the center of the f.theta. Lens 67, the laser light is incident on the workpiece almost vertically. However, as shown in FIG. 10B, the laser beam 61 is f.
When scanning is performed on the outer edge portion of the θ lens 67, the incident angle of the laser beam with respect to the workpiece becomes shallow.

Normally, the incident angle of this laser processing does not have a great influence when removing a flat electrode, but in the processing inside the groove, the laser light interferes with the entrance of the groove depending on the incident angle, and the inside of the groove is affected. Not only is not processed normally,
This causes problems such as damage to the electrode at the entrance of the groove.

The present invention has been made to solve the above-mentioned problems, and it is possible to precisely irradiate a high-energy beam into the inside of the groove of a workpiece having a plurality of grooves formed therein. An object of the present invention is to provide a laser processing apparatus capable of high-speed processing and performing high-precision processing that does not interfere with a portion other than a processing portion, and in particular, an electrode formed on the surface of a piezoelectric body having a plurality of grooves. (EN) A laser processing apparatus capable of manufacturing a high-quality piezoelectric ink jet head at low cost by efficiently removing a part of each of the grooves and separately forming an independent electrode for each side surface of the groove.

[0025]

In order to achieve this object, a laser processing apparatus of the present invention irradiates a high-energy beam to the inside of the groove of a workpiece having a plurality of grooves formed therein. And a laser oscillator that oscillates the high-energy beam, a scanning mechanism that scans the workpiece by changing the optical path of the high-energy beam emitted from the laser oscillator, and holds the workpiece. A table that can be arbitrarily moved in the extension direction of the processing plane, a calculation unit that calculates in advance each of the incident angles of the high-energy beams incident on the plurality of grooves, and the incident angle of the groove to be processed is predetermined. When it is within the range, only the scanning means is driven so that the high energy beam is incident into the groove, and when the incident angle is out of the predetermined range, the table is moved. After adjusting the position of the workpiece such that the incident angle by moving the Le high energy beam within a predetermined range is incident on the groove, and a control means for causing the laser processing by the scanning means.

The laser beam has a groove width W and a groove depth D.
Tan ⁻¹ (2
D / W) <θ ≦ 90 ° may be controlled by the control means so that the light always enters at an incident angle θ.

The object to be processed has a side wall at least a part of which is made of a piezoelectric element and a plurality of grooves separating the side wall, and a conductive layer is formed on the surface where the groove is formed. An actuator member, irradiating a high-energy beam to the conductive layer formed on the inner surface of the groove,
Each side surface of the groove may be separated into an independent electrode.

The high energy beam is 1.06.
It may be YAG laser light having a wavelength of μm.

The high energy beam is 532n.
It may be YAG laser light having a wavelength of m.

The minimum diameter of the high energy beam may be smaller than the width of the groove.

Further, the high energy beam may be incident so as not to interfere with the outer edge of the opening of the groove.

The high energy beam may move relative to the actuator member at a speed of 100 mm or more per second.

[0033]

In the laser processing apparatus according to claim 1 of the present invention having the above structure, the workpiece having the plurality of grooves is irradiated with the high energy beam emitted from the laser oscillator,
The inside of the groove is processed. When processing the inside of the groove, the beam irradiation is performed within a predetermined incident angle range such that the laser light reaches the inner surface of the groove that needs to be processed and the high energy beam does not interfere with other portions such as the entrance of the groove. When practicable, processing is performed only by scanning the high energy beam without moving the table. On the other hand, when the incident angle of the high-energy beam becomes shallow and the above requirements are not satisfied, the table is moved and the piezoelectric body is moved to a position where the incident angle satisfies the above requirements. After that, the scanning mechanism is driven to scan the beam. Therefore, laser processing can be performed at high speed, and productivity is improved.

Further, in the laser processing apparatus according to the second aspect of the present invention, the incident angle θ of the laser beam with respect to the bottom surface of the groove of the piezoelectric body, which has the groove width W and the groove depth D, is determined by the means described above. By action, tan ^-1 (2D / W)
<Θ ≦ 90 degrees is maintained. As a result, it is possible to perform laser processing only on the bottom surface of the groove.

In the laser processing apparatus according to the third aspect, by irradiating a high-energy beam to remove the conductive layer formed on the inner surface of the groove, a piezoelectric actuator member having independent electrodes on each side surface is provided. Formed with high precision and productivity.

In the laser processing apparatus according to the fourth aspect, a YAG having a high power density and a wavelength of 1.06 μm is used.
The inner surface of the groove is rapidly processed by the laser light.

In the laser processing apparatus according to the fifth aspect, the YAG laser beam having a wavelength of 532 nm is used.
The inner surface of the groove is processed. Therefore, since a laser beam having a high power density and a small spot diameter is used, the processing speed is high and the processing can be performed with high accuracy. Therefore,
Laser processing can be performed in response to high integration of grooves.

In the laser processing apparatus according to the sixth aspect, the electrode on the inner surface of the groove is removed at the minimum diameter portion of the high energy beam which is smaller than the width of the groove. Therefore,
Finer processing becomes possible.

Further, in the laser processing apparatus according to the seventh aspect, the high-energy beam is incident so as not to interfere with the outer edge of the opening of the groove to prevent interference by the beam at the entrance of the groove.

In the laser processing apparatus according to the eighth aspect, the high-energy beam relatively moves with respect to the actuator member at a speed of 100 mm or more per second to efficiently perform laser processing on the inner surface of the groove. Since the scanning is performed at a high speed of 100 mm or more per second, heat input to the work piece is minimal and local, and does not affect characteristic changes of the work piece.

[0041]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

First, an example of the structure and manufacturing method of the ink jet head of the present invention will be described with reference to FIGS.

As shown in FIG. 2, a piezoelectric ceramic substrate 1, which is a piezoelectric body, is provided with a number of grooves which are parallel to each other and serve as ink chambers 2, and are side walls of the grooves, and piezoelectric side walls 7 separating the grooves. Are formed. Piezoelectric ceramics substrate 1
A lid 6 having an ink supply port 5 is adhered to a surface (upper surface in FIG. 3) of the groove processing side, so that the groove becomes the ink chamber 2.
A nozzle plate 3 is bonded to one end surface of the piezoelectric ceramic substrate 1 and the lid 6 so that the nozzle 4 corresponds to one end of the ink chamber 2. The ink chamber 2 is connected to an ink storage tank (not shown) via the ink supply port 5.

With this structure, the cross section of the ink chamber 2 has a rectangular shape surrounded by the piezoelectric side wall 7 and the upper lid 6. The piezoelectric side wall 7 is composed of two piezoelectric portions whose polarization directions 8 are opposite to each other.
An electrode 9 is formed on the surface of the piezoelectric side wall 7. Each electrode 9 is connected to a pattern (not shown) formed on the upper surface of the piezoelectric ceramic substrate 1, and the pattern is connected to the control unit via a flexible substrate (not shown).

The ink jet head having the above structure is formed by the following manufacturing method.

First, a large number of parallel grooves serving as ink chambers 2 are formed in a piezoelectric ceramic substrate 1 to which piezoelectric layers having polarization directions opposite to each other are adhered. As a means for forming the groove, a diamond blade having a thickness capable of forming a desired ink chamber groove width is used, and the groove is formed by dicing.

Next, the electrode 9 is formed on the surface of the piezoelectric ceramic substrate 1 by a metal thin film forming means such as vacuum deposition, sputtering, or plating. At this time, the electrode 9 is also formed on the entire surface in the groove and the upper end surface of the piezoelectric side wall 7. If the electrode is not formed in a large area, the resist film is separately applied, and then the electrode is formed by the above-described means. Then, the lift-off method is used to chemically remove the unnecessary portion of the electrode. The method may be applied.

Next, a high energy beam of YAG is applied to the electrode 9 formed on the bottom surface of the groove which is the ink chamber 2.
The electrode 9 is removed by irradiating the laser beam 10.

An example of electrode removal by the laser processing apparatus of the present invention will be described in detail below with reference to FIGS. 1 and 3.

The wavelength 1.Emitted from the YAG (yttrium aluminum garnet) laser oscillator 11 was detected.
06 μm (micrometer) YAG laser light 10
Is incident on the first scanning mirror 12 disposed on the optical path thereof, is then redirected, and then is incident on the second scanning mirror 13 to be redirected. An f · θ lens 14 is arranged below the second scanning mirror 13. The YAG laser light 10 is incident on the f.theta. Lens 14 to be condensed and forms a focal point 15 at a position of a predetermined focal length F from the f.theta. Lens 14.

The above two sets of scanning mirrors 12 and 13
Galvanometers 16 and 17 and a control device therefor are connected to one end of each of them. With these configurations, two sets of scanning mirrors 12 and 13 can be swung at high speed.

Piezoelectric ceramics substrate 1 which is a workpiece
Is mounted on a precision table 18 that can slide in one direction,
It is arranged below the f · θ lens 14. Here, the piezoelectric ceramic substrate 1 is arranged so that the focal point 15 of the YAG laser beam 10 is formed near the electrode 9 formed on the bottom surface of the groove, which is the ink chamber 2 that is the portion to be processed. It At the focal point 15 of the YAG laser light 10 of this embodiment, the spot diameter of the laser light is 0.1 mm or less, and a high power density can be obtained. The electrode 9 irradiated with this high power density YAG laser beam 10 is
It is heated in an extremely short time and leads to evaporation. As a result, the electrode 9 is locally removed from the surface of the piezoelectric ceramic substrate 1 to form an insulating portion.

The above processing is performed by oscillating the first scanning mirror 12 at high speed in the longitudinal direction of the bottom surface of the groove of the ink chamber 2 and irradiating the YAG laser beam 10 to irradiate the bottom surface of one groove. The electrode removal process is completed.
After that, the relative position between the YAG laser beam 10 and the piezoelectric ceramic substrate is changed to shift to the processing of the adjacent ink chamber 2,
Continue laser processing.

The laser processing apparatus of this embodiment recognizes the incident angle of the YAG laser light 10 with respect to the workpiece and changes the relative position of the YAG laser light 10 and the piezoelectric ceramic substrate according to the incident angle. To be controlled. The incident angle of the YAG laser light 10 is calculated in advance for each machining route of each groove before machining. The method of changing the relative position between the YAG laser beam 10 and the piezoelectric ceramic substrate differs depending on whether the calculated incident angle is within the predetermined range or outside the predetermined range. The specific control method will be described below.

Here, the cross-sectional shape of the groove which is the ink chamber 2 is shown in FIG. Consider a case where the central portion of the bottom surface of the groove is irradiated with the YAG laser light 10 in the groove shape in which the groove width is W and the groove depth from the surface is D. YA
When the optical path 19 of the G laser light 10 is represented by a straight line, YA
The incident angle θ of the G laser light 10 with respect to the groove bottom surface is tan
^-1 (2D / W) <θ ≦ 90 °, YAG
The optical path 19 of the laser light 10 does not interfere with anything other than the groove bottom surface. In reality, the YAG laser light 10 has a certain diameter, and does not necessarily match the linear approximation as in the above calculation formula. However, since the laser light used for the present processing generally has a Gaussian mode energy distribution with extremely high central intensity, processing by the outer edge of the laser light can be ignored. Furthermore, since there is room to move the irradiation position from the center of the groove bottom as long as the groove width allows,
The effects of the present invention can be sufficiently exhibited even by the above-described linear approximation.

At the above incident angle θ where the YAG laser beam 10 is not applied to the area other than the bottom surface of the groove, the precision table 18 is used.
Driving is unnecessary. Therefore, the second scanning mirror 13 is slightly displaced to move the focus 15 of the laser light to the groove of the adjacent ink chamber 2, and the first scanning mirror 12
The above laser processing is repeated by rocking. The YAG laser light 10 is scanned at a high speed of 100 mm or more per second, but it can be processed with the minimum heat input required to remove the electrodes. Further, since the speed is 100 mm / sec or more, the heat input to the piezoelectric ceramic substrate 1 is minimal and local, and the influence on the characteristic change of the piezoelectric ceramic substrate 1 can be neglected. When a scanning mirror is used, it is generally 1000 mm / s.
It is possible to scan with the laser light at the above speed, and even in the case of having several tens of grooves, processing can be performed in an extremely short time.

When the incident angle θ of the YAG laser beam 10 becomes shallow and the laser beam may not reach the bottom surface of the groove and may be irradiated to a portion other than the bottom surface of the groove (incident angle θ falls outside the above range). If so, the precision table 18 is driven. As a result, the ceramic substrate 1 is moved to a position where the incident angle θ of the YAG laser light 10 is such that it does not irradiate other than the bottom surface of the groove. After that, the YAG laser light 10 caused by the swing of the first scanning mirror 12 described above.
The removal of the electrode 9 is repeated by scanning.

In the above processing control, the operation cycle may be determined in advance in consideration of the groove shape and the like, and this work is not particularly complicated.

Next, the ink jetting operation of the ink jet head will be described with reference to the sectional view of the piezoelectric ink jet head shown in FIG.

In the ink jet head, when the ink chamber 2b is selected according to the given print data, a positive drive voltage is applied to the metal electrodes 9a and 9d,
The metal electrodes 9b and 9c and other metal electrodes corresponding to the ink chambers are grounded. As a result, a driving electric field is generated on the piezoelectric side wall 7a toward the right in the figure, and a driving electric field is generated on the side wall 7b toward the left in the figure. At this time, since the respective driving electric field directions and the polarization direction 8 of the piezoelectric ceramics plate are orthogonal to each other, the side walls 7a and 7b are bent inside the ink chamber 2b so as to bend at the joint portion of the piezoelectric ceramics plate due to the piezoelectric thickness sliding effect. Rapidly deforms in the direction (Fig. 4
(B)).

Due to these deformations, the volume of the ink chamber 2b is reduced, the ink pressure in the ink chamber 2b is rapidly increased, a pressure wave is generated, and ink droplets are ejected from a nozzle (not shown) communicating with the ink chamber 2b. Is jetted.

When the application of the drive voltage is stopped, the side walls 7a and 7b return to the positions before the deformation (see FIG. 4A), so that the ink pressure in the ink chamber 2b is lowered and the ink supply port 5 is discharged. Ink is supplied into the ink chamber 2b through the manifold.

However, the above operation is only a basic operation, and in the case of being embodied as a product, first, a drive voltage is applied in the direction of increasing the volume, and then the ink is supplied to the ink chamber 2b first. The application of the drive voltage is stopped and the side walls 7a, 7
Ink droplets may be ejected by returning b to the position before deformation (see FIG. 4A). Further, a drive voltage pattern called a cancel pulse may be added after an appropriate time in order to attenuate the pressure wave in the ink chamber after the ink droplets are ejected.

In the ink jet head having such a structure, it is not possible to eject ink droplets from two nozzles communicating with two adjacent ink chambers 2 at the same time.
For example, after ejecting ink droplets from nozzles communicating with odd-numbered ink chambers 2a and 2c from the left end, ink droplets are ejected from nozzles communicating with even-numbered ink chambers 2b,
Next, ink droplets are ejected by dividing the ink chamber 2 and the nozzles into two groups so that ink droplets are ejected from odd numbers again. Further, the ink chamber 2 and nozzles may be divided into three or more groups to eject ink droplets.

As described above, in the method of manufacturing the piezoelectric ink jet printer of this embodiment, the driving of the precision table is limited to the necessary minimum, and the scanning mechanism composed of two sets of scanning mirrors 12 and 13 is used as much as possible. Then, since the laser processing is continued, it becomes possible to perform the laser processing at a high speed. In particular, in the manufacture of the inkjet head of the present embodiment, a part of the electrode can be efficiently removed from the electrode formed on the surface of the piezoelectric body, particularly the electrode formed inside the groove. Further, it is possible to remove only the electrode on the bottom surface of the groove without affecting other parts.

As a result of the above, it is possible to produce a high-quality ink jet head at a low cost, which is a significant industrial effect.

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the spirit of the invention. For example, the type of high-energy beam such as laser light, the beam focusing condition of the optical system, and the like may be appropriately selected according to the size of the portion to be removed. For example, when a laser beam having a wavelength of 1.06 μm (micrometer) which is a standard wave of a YAG laser is used and an f · θ lens having a focal length of 150 mm is used in a single mode (Gaussian mode), the minimum spot diameter is , About 60 to 80 μm. The minimum spot diameter can be further reduced by using an f.theta. Lens having a shorter focal length. Y of the wavelength of 532 nm (nanometers), which is the second harmonic of the YAG laser
The minimum spot diameter can be reduced to 40 μm or less by using AG laser light. Therefore, it goes without saying that it is possible to cope with high integration of parts in the future.

When the YAG laser beam 10 is irradiated, one end of the ink chamber 2 is connected to the opening end 1 to which the nozzle plate 3 is connected.
7, an air such as an inert gas may be introduced, and the air may prevent the molten scattered matter generated when the electrode 9 is irradiated with the YAG laser light 10 from adhering to the inside of the ink chamber 2. .

In the ink jet head of this embodiment, the ink chambers 2 are adjacent to each other with the piezoelectric side wall 7 interposed therebetween.
Non-ejection regions where ink is not supplied may be provided on both sides of each ink chamber. For example, the electrodes formed on the inner surface of the ink chamber are not separated but electrically connected, and the electrodes formed on the inner surface of the non-ejection region may be separated.

Further, in this embodiment, the piezoelectric side wall 7 is composed of two piezoelectric layers whose polarization directions are opposite to each other. However, the piezoelectric side wall 7 is composed of a non-piezoelectric layer and a piezoelectric layer. Good.

[0071]

As is apparent from the above description, according to the laser processing apparatus of the present invention, the driving of the table for holding the workpiece is limited to the necessary minimum, and the scanning mechanism is used as much as possible. Since the laser processing is continued, the processing inside the groove can be performed at high speed and with high accuracy.

Particularly, by irradiating the conductive layer formed on the inner surface of the groove of the piezoelectric ceramics with a high energy beam such as YAG laser light, the electrode is efficiently removed, and an independent electrode is formed on each side surface. It is possible to easily manufacture the actuator including the side wall having. Further, it is possible to remove only the electrode on the bottom surface of the groove without affecting other parts. As a result of the above, there is an industrially significant effect that an inexpensive and high-quality inkjet head can be manufactured.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a laser processing apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an inkjet head according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating an incident angle of laser light by the laser processing apparatus according to the embodiment.

FIG. 4 is a cross-sectional view showing the operation of the inkjet head of the above-described embodiment.

FIG. 5 is a perspective view showing a conventional inkjet head.

FIG. 6 is a cross-sectional view showing the operation of a conventional inkjet head.

FIG. 7 is an explanatory diagram showing an example of a conventional laser processing apparatus.

FIG. 8 is an explanatory diagram showing an example of a conventional laser processing apparatus.

FIG. 9 is an explanatory diagram showing an example of a conventional laser processing apparatus.

FIG. 10 is a cross-sectional view illustrating an incident angle of laser light of a conventional laser processing device.

[Explanation of symbols]

 1 Piezoelectric Ceramics Substrate 2 Ink Chamber 7 Piezoelectric Sidewall 9 Electrode 10 YAG Laser Light 12 First Scanning Mirror 13 Second Scanning Mirror 14 f · θ Lens 18 Precision Table

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G02B 26/10 104 B41J 3/04 103H

Claims (8)

[Claims] 1. A laser processing apparatus for irradiating a high-energy beam to the inside of a groove of a workpiece having a plurality of grooves formed therein, comprising: a laser oscillator that oscillates the high-energy beam; and an emission from the laser oscillator. A scanning mechanism for scanning the workpiece by changing the optical path of the high-energy beam generated, a table that holds the workpiece and is movable arbitrarily in the extension direction of the machining plane, and the plurality of grooves. Calculating means for preliminarily calculating each incident angle of the high-energy beam to be incident, and when the incident angle of the groove to be processed falls within a predetermined range, only the scanning means is driven to cause the high-energy beam to move into the groove. When the incident angle is out of the predetermined range, the table is moved so that the high energy beam is emitted within the predetermined range. After adjusting the position of the workpiece to be incident within the laser machining apparatus being characterized in that a control means for causing the laser processing by the scanning means. 2. The incident angle θ of the laser light with respect to the bottom surface of the groove of the workpiece having the groove width W and the groove depth D is tan ⁻¹ (2D / W) <θ ≦ 90 °. The laser processing apparatus according to claim 1, wherein the laser beam is controlled by the control means so that the laser beam is always incident on the laser. 3. The work piece has a side wall at least a part of which is made of a piezoelectric element, and a plurality of grooves separating the side wall, and a conductive layer is formed on the surface on the side where the groove is formed. The actuator member, wherein a high-energy beam is applied to a conductive layer formed on the inner surface of the groove, and separate side electrodes are formed on each side surface of the groove. Laser processing equipment. 4. The high energy beam is 1.06 μm.
The laser processing device according to claim 1, wherein the laser processing device is YAG laser light having a wavelength of m. 5. The high energy beam is 532 nm
The laser processing apparatus according to claim 1, wherein the laser processing device is a YAG laser beam having a wavelength of. 6. The minimum diameter of the high energy beam is smaller than the width of the groove.
The laser processing apparatus according to any one of 1. 7. The laser processing apparatus according to claim 6, wherein the high energy beam is incident so as not to interfere with the outer edge of the opening of the groove. 8. The laser processing apparatus according to claim 1, wherein the high-energy beam moves relative to the actuator member at a speed of 100 mm or more per second.