JPH02187346A - Inkjet recording head and method for manufacturing the head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to an inkjet recording head and a method for manufacturing the recording head, and more specifically, the present invention relates to an inkjet recording head and a method for manufacturing the recording head. The present invention relates to a recording head having a plate) and a method for manufacturing the same.

[Prior Art] Recently, excimer laser light has come to be used to process the orifice of this type of recording head. This orifice processing using excimer laser light is performed after bonding a resin film that will become an orifice plate to the opening surface where the opening communicating with the ink liquid path is arranged.
This was done by irradiating it with light.

This situation is shown in FIG. In the figure, 1 is an excimer laser device, 2 is a laser beam oscillated from the excimer laser device, 3 is a lens for converging the laser beam, and 4 is a lens for softening all or part of the orifice pattern. A mask, 5 an inkjet recording head main body having a resin film bonded to the opening surface of an ink liquid path, and 6 a movable stage.

FIG. 9 shows details of the inkjet recording head main body 5 in which orifices have been processed according to such a device configuration 4''. FIG. 9 is a sectional view of the head main body. In this figure, 7 constitutes an ink liquid path. 8 is a substrate patterned with an ejection energy generating element; 9 is an opening communicating with an ink liquid path; 10 is an orifice plate made of a resin film; 11 is an orifice plate formed on orifice.

Further, 14 is an ink liquid path, and 15 is an electrothermal converter as an ejection energy generating element.

As shown in FIG. 9, in the conventional orifice machining using an excimer laser as shown in FIG. 8, the shape of the orifice is tapered, widening toward the discharge port.

[Problems to be Solved by the Invention] However, such an inkjet recording head having a tapered orifice that expands toward the ejection port has the following problems.

That is, if the orifice has the shape described above,
In some cases, the amount of ink droplets and ink ejection speed necessary to record an image or the like cannot be obtained, resulting in unstable ejection characteristics, which may lead to a decrease in the quality of the recorded image.

The present invention has been made to solve the above-mentioned conventional problems, and by forming the tapered shape of the orifice so that the ejection port side becomes narrower, the amount and ejection speed of ink droplets necessary for recording can be reduced. It is an object of the present invention to provide an inkjet recording head that can be obtained stably and sufficiently, and a method for manufacturing the same.

a substrate formed with an ejection energy generating element that generates the ejection energy to be used; a top plate having a recessed portion for forming an ink liquid path corresponding to a location where the ejection energy element is disposed by being joined to the substrate; In a method for manufacturing an inkjet recording head comprising an ejection port forming member formed with an ejection port for ejecting ink in communication with an ink liquid path, after integrating the top plate and the ejection port forming member,
It is characterized in that the discharge port is formed by irradiating excimer laser light from the concave side.

[Function] According to the above configuration, it is possible to obtain an inkjet recording head having a tapered orifice whose cross-sectional area decreases in the ejection direction, thereby reducing the amount of ink droplets necessary for recording. A stable discharge speed can be obtained.

[Means for Solving the Problems] To this end, in the present invention, in order to eject ink, [Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an inkjet recording head according to an embodiment of the present invention, which is disposable and has an integrated ink tank.

The inkjet recording head shown in the figure has a top plate integrally formed with recesses (hereinafter referred to as grooves) for forming an ink liquid path and a common liquid chamber, an orifice plate IO, and an electrothermal converter for generating ejection energy. A substrate (hereinafter referred to as a discharge heater) and an A1 wiring for supplying an electric signal thereto are formed on an St substrate by film-forming technology.
A recording head main body (not shown) configured by joining a heater board (hereinafter referred to as a heater board) is provided.

Further, 600 in the figure is a sub-ink tank disposed adjacent to the recording head main body, and this sub-ink tank 60
0 and the above bodies are supported by lids 300 and 800. Furthermore, 1000 is the cartridge body, 110
0 is a lid member of the cartridge body. An ink tank is built inside the cartridge main body, and ink is appropriately supplied to the sub-ink tank 600.

Figure 2 shows how an orifice plate, which is formed integrally with the top plate, is irradiated with excimer laser light from the ink liquid path side to form orifices, and the elements are similar to those shown in Figure 7. Elements are given the same reference numerals. In the figure, 1 is a laser oscillation device that oscillates KrF excimer laser light, and 2 is a wavelength of 248 mm oscillated from the laser oscillation device 1.

A pulsed laser beam with a pulse width of about 15 nsec, 3 is a synthetic quartz lens for focusing the laser beam 2, 4
is a projection mask made of vapor-deposited aluminum that can shield the laser beam 2, and has 21 holes with a diameter of 133 μm.
A plurality of them are arranged at a pitch of 2 μm to form an orifice pattern.

FIGS. 3(^) and 3(B) are a plan view and a partially enlarged view of the substrate (heater board) 8 according to this embodiment.

In the figure (A), 101 is a heater board base according to this example, and 103 is a discharge heater section. 104 is a terminal, which is connected to the outside by wire bonding. 102
is a temperature sensor, which is formed in the discharge heater section 3 by the same film forming process as the discharge heater section 103 and the like. Same figure (
B) is an enlarged view of part B including the sensor 102 in FIG. Further, 108 is a heat-retaining heater for heating the head.

Like the other parts, the sensor 102 has extremely high precision because it is formed using a film formation process similar to semiconductors, and the sensor 102 is made of aluminum, titanium, tantalum, tantalum pentoxide, niobium, etc., which are the constituent materials of the other parts. It can be made from a material whose conductivity changes depending on temperature. For example, among these, titanium is a material that can be placed between the heat generating resistor layer and the electrode that make up the electrothermal conversion element in order to improve their adhesion, and tantalum is a material that can be placed between the heat generating resistor layer and the electrode to improve the cavitation resistance of the protective layer on the heat generating resistor layer. There is a material that can be placed on top of it to enhance it. In addition, to reduce process variations, the line width is made thicker,
In order to reduce the influence of wiring resistance etc., the meandering shape is used to increase the resistance.

Similarly, the heat-retaining heater 108 can be formed using the same material (for example, HfB2) as the heat-generating resistance layer of the discharge heater 15, but it can also be formed using other materials constituting the heater board, such as aluminum, tantalum, titanium, etc. You may do so.

FIG. 4(A) shows an example of the structure of the top plate 7 according to this example.

The top plate 7 according to this example has an ink liquid path groove 14 and an ink discharge port (
It has a desired number of orifices 11 (two in the figure for simplicity), and an orifice plate 10 is integrally provided.

In the configuration example shown in FIG. 4(A), the top plate 7
This is made of a resin having excellent ink resistance such as polysulfone, polyethersulfone, polyphenylene oxide, or polypropylene, and is molded together with the orifice plate 10 in a mold.

Next, a method of forming the ink channel groove 14 and orifice 11 will be explained.

As for the ink channel grooves, the resin is molded using a mold in which fine grooves with a reverse pattern are formed by a method such as cutting, thereby forming the ink channel grooves 14 on the top plate 7.

Regarding the formation of the orifice, the mold is molded without the orifice 11, and as explained in FIG. The orifice 11 is formed by irradiating laser light to remove and evaporate the resin.

Details of orifice formation are shown in FIG. 4(B). As is clear from the figure, the excimer laser light 2 is irradiated onto the orifice plate 10 from the ink liquid path 14 side through the aforementioned mask 4. Furthermore, the excimer laser light 2 is converged at θ1 = 2 degrees on one side with respect to the optical axis 13, and the optical axis 13 is 02 = I from the vertical direction of the orifice spray)-10.
The beam is irradiated at an angle of 0 degrees.

In this way, by irradiating the laser beam from the ink liquid path side, the cross-sectional area of the tapered orifice becomes smaller in the ejection direction.

Here, the excimer laser light used in this example will be explained.

This excimer laser is a laser that can emit ultraviolet light.It has high intensity, good monochromaticity, directivity, can emit short pulses, and can greatly increase energy density by focusing it with a lens. has advantages.

An excimer laser oscillator is a device that can oscillate short pulses (15 to 35 ns) of ultraviolet light by discharging and exciting a mixture of rare gas and halogen.

Xe-CjZ and Ar-F lasers are often used. The oscillation energy of these is several 100 mJ/pulse, and the pulse repetition frequency is 30 to 1000 Hz.

When a polymer resin surface is irradiated with high-intensity short-pulse ultraviolet light such as excimer laser light, the irradiated area instantly decomposes and scatters with plasma emission and impact sound.
tive Photodecomposition (A
PD) process occurs, which allows processing of polymer resins.

In this way, when comparing the processing accuracy of excimer laser and that of other lasers, for example, polyimide (PI)
) Laser as excimer laser and other Y
When irradiated with AG laser and CO2 laser, the rF laser creates a clean hole because the wavelength that absorbs PI light is in the UV region, but YAG laser, which is not in the UV region, creates a hole but the edge surface becomes rough and infrared rays create a hole. Some 00
2 Laser creates a crater around the hole.

Also, metals such as SUS, and opaque ceramics.

Since SI and the like are not affected by excimer laser light irradiation in the atmosphere, they can be used as a mask material in excimer laser processing.

FIG. 5 is a perspective view of a recording head main body constructed by joining the above-mentioned heater board 8 and top plate 7. As shown in FIG.

As shown in the figure, a heater board 8 having a discharge heater 15 and the like is butted against and joined to an orifice plate 1o,
Obtain the recording head body.

With the above configuration, there is no need to align or bond the top plate and the orifice plate as in the past, so there is no alignment error or misalignment during bonding, which reduces the number of defective products and shortens the process. , it was possible to contribute to mass production and cost reduction of recording heads. Furthermore, since there is no bonding process between the top plate and the orifice plate as in the conventional art, there is no risk of clogging the orifice or ink flow path due to adhesive flowing in. Furthermore, when joining the heater board 8 and the top plate 7 that integrates the orifice plate 10, positioning in the flow path direction can be performed by abutting the heater board 8 against the end surface of the orifice plate 10 on the opposite side to the discharge side end surface. , the overall positioning and assembly process is facilitated. In addition, there is no fear of the orifice plate peeling off as in the prior art.

FIGS. 6(A) and 6(B) show another embodiment of the present invention, and are a perspective view and a sectional view, respectively, of a top plate integrally formed with an orifice plate.

In this example, the irradiation angle, that is, the above-mentioned θ2, is set to 45 degrees depending on the shapes of the top plate and the orifice plate. That is, when irradiating laser light from the ink liquid path side, the irradiation angle is changed depending on the shape of the top plate or the like.

The recording head configured according to the above two embodiments and the ninth embodiment.
The table below shows a comparison of the results of recording using the conventional recording head shown in the figure.

As is clear from the above table, when the recording head according to this example is used, the ejection speed is more than doubled, and as a result, the accuracy of the droplet landing position is improved, and good recording results can be obtained. . It is also known that when the orifice shape is used as in this example, the volume of the ejected droplet becomes large, which gives good results to the recording density.

Note that in the above two embodiments, the orifice plate was integrated with the top plate, but the application of the present invention is not limited to this, and the orifice plate is separately joined to the top plate, and then the orifice processing as described above is performed. Of course, you can still get the desired effect by doing so.

The recording head main body described above can be obtained in the form of a cartridge as shown in FIG. 1, and can be used to configure an inkjet printer as shown in FIG. 7, that is, an inkjet printer using a disposable cartridge. Can be done.

In addition, in FIG. 7, 80 is the cartridge shown in FIG. 1, and this cartridge 80 is fixed on the carriage 51 by a pressing member 81, which can reciprocate in the longitudinal direction along the shaft 21. It becomes.

Further, the positioning with respect to the carriage 51 is performed by, for example, 13
This can be done using a hole provided in 00 and a dowel provided on the carriage 15 side.

Furthermore, electrical connections are made to the connection pads provided on the wiring board.
It is only necessary to connect the connectors on the carriage 51.

The ink ejected by the recording head reaches the recording medium 18 whose recording surface is regulated by the platen 19 at a slight interval from the recording head, and forms an image on the recording medium 18.

An ejection signal corresponding to image data is supplied to the recording head from an appropriate data supply source via a cable 16 and a terminal connected thereto. One or more cartridges 80 (two in the figure) can be provided depending on the ink color used.

Further, in FIG. 7, 17 is a carriage motor for scanning the carriage 51 along the shaft 21;
2 is a wire that transmits the driving force of the motor 17 to the carriage 51. Further, zo is a feed motor coupled to the platen roller 19 for conveying the recording medium 18.

[Effects of the Invention] As is clear from the above description, according to the present invention, it is possible to obtain an inkjet recording head having a tapered orifice that decreases in the ejection direction. A stable amount of ink droplets and a stable ejection speed can be obtained.

As a result, the ejection performance such as the landing position accuracy of the ejected droplets and the recording density is improved, and a high quality recorded image can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an inkjet recording head cartridge according to an embodiment of the present invention, FIG. 2 is a schematic diagram of an orifice processing device using excimer laser light, and FIGS. 3 (A) and CB) are according to the present invention. FIGS. 4(A) and 4(B) are a plan view and a partially enlarged view of a heater board according to an embodiment of the present invention, respectively, and FIGS. A perspective view and a cross-sectional view, FIG. 5 is a perspective view of an inkjet recording head main body constructed by joining the heater board shown in FIG. 3 and the top plate shown in FIG. 4, FIG. 6 (A), and (B) is a perspective view and a sectional view of a top plate integrated with an orifice plate showing another embodiment of the present invention, and FIG. 7 shows an example of an inkjet printer equipped with a recording head according to an embodiment of the present invention. 8 is a schematic diagram of an orifice processing device showing a conventional example of processing an orifice using excimer laser light. FIG. 9 shows an orifice processed by the device shown in FIG. 8. FIG. DESCRIPTION OF SYMBOLS 1... Laser oscillation device, 2... Laser beam, Fig. 1 3... Condensing lens, 4... Mask, 7... Top plate, 8... Substrate (heater board), 10 ... Orifice plate, 11 ... Orifice, 13 ... Optical axis, 14 ... Ink liquid path, 15 ... Discharge heater. Figure 2 Figure 4 (B) Figure 6 (B) I Figure 7 Figure S Figure 9

Claims (1)

[Scope of Claims] 1) A substrate on which an ejection energy generating element that generates ejection energy used to eject ink is formed;
a top plate having a concave portion for forming an ink liquid path corresponding to a location where the ejection energy element is disposed by being joined to the substrate; and an ejection port communicating with the ink liquid path for ejecting ink. In the method of manufacturing an inkjet recording head, the top plate and the ejection port forming member are integrated, and then an excimer laser beam is irradiated from the recess side to form the ejection port. A method of manufacturing an inkjet recording head, the method comprising forming an outlet. 2) The method of manufacturing an inkjet recording head according to claim 1, wherein the top plate and the ejection port forming member are integrally molded. 3) An inkjet recording head manufactured by the manufacturing method according to claim 1 or 2. 4) The inkjet recording head according to claim 3, wherein the ejection energy generating element is configured to apply thermal energy to the ink. 5) The inkjet recording head according to claim 3, wherein the ejection energy generating element is an electrothermal converter.