JP2007203650A - Method for manufacturing droplet discharge head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a droplet discharge head enabling a nozzle working which copes with both a desired taper shape and a discharging port accuracy. <P>SOLUTION: A perforation working with the taper shape of a large angle is performed for a work 18 at the first working position. The work 18 is moved to the second working position (=imaged position) and worked with a laser beam 12 imaged with the same pattern as the one of the mask 14. Thereby, the elements such as burr which may affect the discharging performance can be removed by enlarging the opening diameter of the discharging port 24 of a nozzle 22 to an original 20 μm and preparing the pitch between the opening diameter and the nozzle together with the shape near the discharging port 24. Since the second working is performed with the taper angle of an approximate 8° and a near straight tube structure, the nozzle 22 can be formed with an ideal structure such that the nozzle section has a small taper angle (nearly straight tube) at the neighborhood of the discharging port 24 and a large taper angle at the side far from the discharging port 24 (upper than the middle in Fig.2(b)) as shown in Fig.2(b) when the second working is finished. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a droplet discharge head.

  2. Description of the Related Art Conventionally, in order to achieve high image quality in an ink jet recording apparatus, it is required that nozzles for ejecting ink droplets have high processing accuracy and little variation. For example, the size of the nozzle diameter affects the ejection speed of the ink droplets. Therefore, when the nozzle diameter varies, the droplet speed changes accordingly, so the time for the ejected ink droplets to reach the print surface As a result, the landing position on the paper fluctuates, resulting in a decrease in print image quality.

  Particularly in recent years, high-frequency ejection of high-viscosity ink has been demanded for the high-speed and high-quality requirements of inkjet. As a necessary condition, a tapered nozzle having a high-precision discharge port and having a smaller diameter toward the discharge port is required.

  As one means for realizing a high-precision discharge port, excimer laser processing at an imaging position where a lens is condensed using a mask for resin such as imide is employed. In this case, an uncontrollable taper (the angle is 6 ° to 10 ° on one side), which is also said to be due to the cross-sectional reflection sequentially generated by processing, is inevitably formed. This tapered shape is desirable but not controllable and the shape cannot be changed.

  For example, as a method for obtaining a high-precision nozzle at low cost, a technique for forming a nozzle with stable ejection characteristics using short-wavelength excimer laser light has been disclosed (for example, see Patent Document 1). In the above processing method, the taper of the nozzle is defined by excimer laser processing. In other words, the shape is defined using a taper that can be naturally formed at the focus position of the laser. However, the taper angle is fixed and it is a conical nozzle section and cannot be changed.

  As a means for increasing the taper angle, it has been experimentally confirmed that when the workpiece is processed at a position shifted from the laser imaging position, the taper increases. On the other hand, since the energy density is lowered, there is a problem that the sharpness of processing of the discharge port is impaired and a high-precision discharge port cannot be obtained.

  On the other hand, when processing and forming grooves that become liquid flow paths and holes that become liquid discharge ports using laser light with a high energy density per unit time, high energy per unit time exceeding a certain threshold value When resin is irradiated with high-density laser light, energy is instantly concentrated, causing deformation of the resin, and the processed dimensions of the processed grooves and holes or their pitches are incorrect, and burrs are generated around the penetrating discharge ports. There are harmful effects such as.

  In order to prevent the above processing efficiency, processing accuracy improvement, burr generation, etc., by adjusting the oscillation voltage of the laser beam or the oscillation frequency of the laser beam, or by dimming the laser beam, the object to be processed can be adjusted to the optical axis. There has been proposed a processing method in which the energy density per unit time of laser light is changed continuously or stepwise by moving the laser beam upward (see, for example, Patent Document 2). However, even in this processing method, a technique that can set / control the taper angle to an arbitrary value is not disclosed.

  Further, there has been proposed a machining method in which the workpiece is positioned at the laser defocus position, the number of pulse shots is controlled, and the distance between the machining head and the workpiece (workpiece) is changed (for example, see Patent Document 3). ).

  However, in the above method, the taper angle cannot be changed / controlled, and since it is not a method of forming the through hole at the just focus position, the processing accuracy in the vicinity of the discharge port cannot be maintained.

In consideration of the above-described facts, an object of the present invention is to obtain a method of manufacturing a droplet discharge head that can ensure the accuracy of the discharge port while the taper angle is gradually reduced toward the discharge port.
JP-A-6-206312 JP 2000-158659 A JP-A-4-143090

  It is an object of the present invention to provide a method for manufacturing a droplet discharge head that can perform nozzle processing that achieves both a desired taper shape and discharge port accuracy.

  The method for manufacturing a droplet discharge head according to claim 1 is to perform laser drilling a plurality of times with different taper angles of holes on a workpiece to obtain a nozzle hole having a shape combining a plurality of types of taper angles. Features.

  In the invention having the above-described configuration, it is possible to provide a method for manufacturing a droplet discharge head that can ensure the discharge port accuracy while changing the taper angle toward the discharge port.

  The method for manufacturing a droplet discharge head according to claim 2, wherein the workpiece placed outside the imaging position is laser processed to open a through hole having a tapered shape with a diameter decreasing toward the discharge port. A machining step and a second nozzle machining step in which a through-hole is machined in a workpiece placed at an imaging position to expand the discharge port to a predetermined diameter.

  In the invention having the above-described configuration, it is possible to provide a method for manufacturing a droplet discharge head that can ensure the discharge port accuracy while changing the taper angle toward the discharge port.

  According to a third aspect of the present invention, there is provided a method for manufacturing a droplet discharge head, wherein the laser processing is performed a plurality of times while a workpiece placed outside the imaging position is moved to the imaging position.

  In the invention having the above-described configuration, it is possible to provide a method for manufacturing a droplet discharge head that can ensure the discharge port accuracy while changing the taper angle toward the discharge port.

  According to a fourth aspect of the present invention, there is provided a method for manufacturing a droplet discharge head, comprising: finishing the discharge port of the through hole at an imaging position.

  In the invention having the above-described configuration, it is possible to provide a method for manufacturing a droplet discharge head without burrs or the like that deteriorates discharge characteristics around the discharge port.

  The method for manufacturing a droplet discharge head according to claim 5 is characterized in that nozzle processing is performed using an excimer laser.

  In the invention with the above configuration, if the excimer laser is processed through a beam expander and a microlens array, a large area / multiple nozzle can be processed at the same time. Is further improved.

  According to a sixth aspect of the present invention, there is provided a method for manufacturing a droplet discharge head, wherein the nozzle processing is performed using a femtosecond laser.

  The invention with the above configuration can provide a method for manufacturing a droplet discharge head with high processing efficiency and high processing accuracy.

  Since the present invention has the above-described configuration, a droplet discharge head manufacturing method capable of performing nozzle processing that achieves both a desired taper shape and discharge port accuracy can be achieved.

<Basic configuration>
FIG. 1 shows a manufacturing method of a droplet discharge head which is an example of an image forming apparatus according to the present invention.

  A workpiece 18, which is a material that can be laser-processed, is placed on a processing table 20 that can move in the XY direction and the Z-axis direction, that is, the optical axis direction, and processing is performed with a laser beam 12 emitted from a laser light source.

  At this time, the laser beam 12 is projected onto the shape of the machining pattern by passing through the machining mask 14 on which the desired machining pattern is recorded, and is scaled to a desired magnification by the machining lens 16 and irradiated onto the workpiece 18.

  The workpiece 18 is processed in accordance with the pattern of the irradiated laser beam 12 and is subjected to drilling or the like according to the pattern recorded on the processing mask 14. The above is an example of laser processing by a typical mask imaging method.

When laser processing is completed for one workpiece 18, the processing table 20 moves with the workpiece 18 placed thereon, and the next workpiece 18 is processed by the laser beam 12. At this time, as described below, the machining table 20 moves in the Z-axis direction between the start and end of laser processing for one workpiece 18, and a plurality of times of lasers are performed at a plurality of positions on the optical axis. Processing with light 12 is performed.
<First Embodiment>
2 to 3 show a nozzle processing method according to the first embodiment of the present invention.

  As shown in FIG. 2A, the workpiece 18 can be moved in the optical axis direction by an elevating means (not shown), and can be moved from the first machining position to the second machining position during the nozzle machining process. .

  The point that the laser beam 12 is projected onto the shape of the processing pattern by passing through the processing mask 14 on which the desired processing pattern is recorded, is changed to a desired magnification by the processing lens 16, and is irradiated onto the workpiece 18. There is no difference from the mask pattern method.

  In this embodiment, the workpiece 18 is first drilled into a tapered shape having a large angle (in this case, 20 °) at the first machining position. At this time, since the position of the workpiece 18, that is, the first processing position is out of the imaging position of the processing lens 16, the laser beam 12 does not form an image according to the pattern of the mask 14, and FIG. As shown in FIG. 3A, the nozzle 22 has a tapered cross section having a large angle. Here, irradiation of 150 pulses is performed at an output of 1.28 J / cm ^ 2.

  At this time, the opening diameter on the discharge side is smaller than the original discharge port diameter (here, 20 μm) (here, 10 to 15 μm) because the taper angle is large. For this reason, a desired taper angle can be obtained, but the opening diameter of the nozzle 22 is insufficient. Therefore, the processing is performed again at the second processing position in order to obtain the original opening diameter.

  That is, the workpiece 18 is moved to the second processing position (= image formation position) as shown in FIG. 2A, and the laser beam 12 imaged according to the pattern of the mask 14 as shown in FIG. 3B. To process. Here, since penetration processing has already been performed, irradiation of 20 pulses is performed at an output of 1.28 J / cm ^ 2.

As a result, the opening diameter of the discharge port 24 of the nozzle 22 is enlarged to the original 20 μm, the opening diameter and the pitch between the nozzles are adjusted, and the shape near the discharge port 24 is adjusted, which may affect the discharge performance such as burrs. Can be removed. Further, in the second processing, the taper angle is about 8 °, and processing close to a straight pipe structure is performed. Therefore, when the second processing is completed, the taper angle near the discharge port 24 is as shown in FIG. An ideal nozzle 22 structure having a small cross section (close to a straight pipe) and a cross section with a large taper angle on the side far from the discharge port 24 (upper side in the figure) can be obtained.
Second Embodiment
FIG. 4 shows a method of manufacturing a droplet discharge head according to the second embodiment of the present invention.

  As shown in FIG. 4A, it is assumed that the workpiece 18 can be moved in the optical axis direction by an elevating means (not shown) and can be moved from the machining start position to the machining end position during the nozzle machining process.

  The laser beam 12 is projected onto the shape of the processing pattern by passing through the processing mask 14 on which the desired processing pattern is recorded, and is scaled to a desired magnification by the processing lens 16 and irradiated onto the work 18. There is no difference from one embodiment.

  In the present embodiment, during machining with the laser beam 12 on the workpiece 18, machining is performed while changing the position of the workpiece 18 continuously or stepwise as shown in FIG. 4B. That is, pulse irradiation of the laser beam 12 is performed while moving the position of the work 18 in the optical axis direction from the processing start position (position deviated from the imaging position) to the processing end position (imaging position).

  First, at the start of machining, a taper shape having a large angle is drilled at the machining start position, and as shown in FIG. 4B, pulse irradiation of the laser beam 12 is performed while moving the workpiece 18 toward the imaging position. However, at this time, the workpiece 18 may be moved continuously without stopping, or may be moved every time a certain number of pulses are irradiated.

  The pulse irradiation of the laser beam 12 is continued while the workpiece 18 is moved, and the molding of the discharge port 24 is completed when the workpiece 18 has finished moving to the processing end position (image forming position). That is, as shown in FIG. 4C, the nozzle 22 has a funnel shape in which the taper angle changes smoothly, or a taper-shaped cross section in which the taper angle changes stepwise.

As a result, the opening diameter of the discharge port 24 of the nozzle 22 is enlarged to the original 20 μm, the opening diameter and the pitch between the nozzles are adjusted, and the shape near the discharge port 24 is adjusted, which may affect the discharge performance such as burrs. Can be removed. Further, since the inner shape of the nozzle 22 is a smooth curved surface or an approximate shape, there is no possibility of adversely affecting ink droplet ejection.
<Manufacturing method 3>
FIG. 5 shows a method of manufacturing a droplet discharge head according to the third embodiment of the present invention.

  As shown in FIG. 5 (a), the workpiece 18 can be moved in the optical axis direction by an elevating means (not shown), and the first and second embodiments can move from the machining start position to the machining end position during the nozzle machining process. There is no difference in form.

  In this embodiment, an excimer laser beam 13 is used in place of the laser beam 12, and the workpiece 18 is irradiated through the microlens array 17 to be processed into a desired shape. At this time, unlike the mask pattern method used in the first and second embodiments, a large area / multiple nozzle can be processed simultaneously without using the mask 14.

  Thereby, the ratio of the loss time required to move the workpiece 18 with respect to the actual machining time is low, and the influence of the time loss to move the workpiece 18 is smaller than that of the mask pattern method of small area / small number nozzle processing. small. For this reason, there is little decline in processing capacity and efficient processing can be performed.

  As an actual machining procedure, first, at the start of machining, the laser is started while drilling into a tapered shape having a large angle at the machining start position, and moving the workpiece 18 toward the imaging position as shown in FIG. 5B. Although the pulse irradiation of the light 12 is performed, for the convenience of focusing using the microlens array 17, the processing start position (outside the imaging position) is more than the processing end position (imaging position) as shown in FIG. It may be close.

  At this time, there is no difference from the second embodiment in that the workpiece 18 may be moved continuously without stopping, or may be moved every fixed number of pulse irradiations.

  The pulse irradiation of the laser beam 12 is continued while the workpiece 18 is moved, and the molding of the discharge port 24 is completed when the workpiece 18 has finished moving to the processing end position (image forming position). That is, as shown in FIG. 5C, the nozzle 22 has a funnel shape in which the taper angle changes smoothly, or a taper-shaped cross section in which the taper angle changes stepwise.

As a result, the opening diameter of the discharge port 24 of the nozzle 22 is enlarged to the original 20 μm, the opening diameter and the pitch between the nozzles are adjusted, and the shape near the discharge port 24 is adjusted, which may affect the discharge performance such as burrs. Can be removed. Further, since the inner shape of the nozzle 22 is a smooth curved surface or an approximate shape, there is no possibility of adversely affecting ink droplet ejection. Furthermore, since a large area / multiple nozzle can be processed simultaneously as compared with the first and second embodiments, the influence on the processing capacity is small.
<Others>
In addition, this invention is not limited to said embodiment.

  For example, in the above embodiment, the method of manufacturing the droplet discharge head is not limited to this, but the present invention is not limited to this method, and may be applied to other types of products as long as it is necessary to process a fine hole with a taper angle. Good.

It is a figure which shows the manufacturing method of the droplet discharge head which concerns on this invention. It is a figure which shows the manufacturing method of the droplet discharge head which concerns on 1st Embodiment of this invention. It is a figure which shows the manufacturing method of the droplet discharge head which concerns on 1st Embodiment of this invention. It is a figure which shows the manufacturing method of the droplet discharge head which concerns on 2nd Embodiment of this invention. It is a figure which shows the manufacturing method of the droplet discharge head which concerns on 3rd Embodiment of this invention.

Explanation of symbols

12 Laser beam 13 Excimer laser beam 14 Processing mask 16 Processing lens 17 Micro lens array 18 Work 20 Processing table 22 Nozzle 24 Discharge port

Claims (6)

A method of manufacturing a droplet discharge head, comprising performing laser processing of a plurality of nozzle holes having different taper angles of a hole to obtain a nozzle hole having a shape in which a plurality of types of taper angles are combined.
A first nozzle processing step of performing laser processing on a workpiece placed outside the imaging position and opening a through hole having a tapered shape whose diameter decreases toward the discharge port;
A second nozzle machining step for machining a through hole in a workpiece placed at an imaging position and expanding the discharge port to a predetermined diameter;
A method for manufacturing a droplet discharge head, comprising:
3. The method of manufacturing a droplet discharge head according to claim 2, wherein the laser processing is performed a plurality of times while the workpiece placed outside the image forming position is moved to the image forming position.
The method for manufacturing a droplet discharge head according to claim 2, wherein finishing processing of the discharge port of the through hole is performed at an imaging position.
The method of manufacturing a droplet discharge head according to claim 1, wherein nozzle processing is performed using an excimer laser.
6. The method for manufacturing a droplet discharge head according to claim 1, wherein nozzle processing is performed using a femtosecond laser.