JP2010115803A - Inkjet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that the interior of an ink channel is damaged by laser beams, resulting in generating a rough surface, hindering a flow of ink, and causing defective printing in the case when the ink channel is formed by irradiating the laser beams in a batch to perform laser welding including the ink channel. <P>SOLUTION: When resin to be set by the laser beams is put in the ink channel (non welding part) and batch irradiation welding by a laser is carried out, the resin is set and also joined. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid discharge head for recording on a recording medium by discharging a liquid such as ink and the like, and more particularly to a liquid discharge head for performing ink jet recording.

  As a liquid discharge head, an ink jet recording head is generally known. With reference to FIG. 7, the configuration of the ink jet recording head will be briefly described. As shown in FIG. 7A, the ink jet recording head H1001 includes a tank holder unit H1003 and a recording element unit H1002 for ejecting ink. The ink is guided to the recording element unit H1002 from an ink tank (not shown) via an ink flow path formed in the tank holder unit H1003.

  In the tank holder unit H1003, an ink flow path is formed by joining a tank holder H1500 shown in FIG. 7B and a flow path forming member H1600 shown in FIG. 7C. As a method for joining the tank holder H1500 and the flow path forming member H1600, a method using ultrasonic welding (Patent Document 1), a method using laser welding (Patent Document 2), and the like are known.

  Of these methods, a method by laser welding will be described. In general, laser welding means that a member that is transparent to laser light and a member that is absorbent to laser light are brought into contact with each other, and the laser light is irradiated in a state where the portions to be welded are in contact with each other. It is the method of joining by. Laser welding has an advantage that dust is less likely to be generated from the welded portion than ultrasonic welding, and is used as an effective means for forming an ink flow path.

  A method of joining the tank holder H1500 and the flow path forming member H1600 using laser welding described in Patent Document 2 will be described with reference to FIG. 8 and FIG. 9 which is a schematic sectional view of FIG.

  A tank holder H1500 that has an absorptivity with respect to the laser beam and a flow path forming member H1600 that has an optical property with respect to the laser beam are brought into contact with each other using a pressing jig 510 (FIG. 8). (A), FIG. 9 (a)). Thereafter, the contact surface 600 is irradiated with laser light in a state where the tank holder H1500 and the flow path forming member H1600 are in contact. (FIG. 8B, FIG. 9B) As a result, the tank holder H1500 and the flow path forming member H1600 are joined (610 is a joined portion) to form an ink flow path. (FIG. 9 (c)).

By the way, there are a scanning method and a batch irradiation method described in Patent Document 2 as laser irradiation methods. As shown in FIGS. 8B and 9B, the scanning method narrows down the spot diameter of the laser beam from the laser irradiator 500, scans it along the locus of the desired joint surface, and then scans the laser beam. This is a method of irradiating. On the other hand, the batch irradiation method is a method of irradiating a desired joint surface with laser light in a batch.
JP 2007-283668 A JP 2005-096422 A

  The ink flow path described above has a fine structure and the structure of the joint surface is also fine. In such a case, there are the following problems in both the scanning method and the batch irradiation method.

  In the case of the scanning method, there is a problem that it takes a very long time to scan and weld a laser beam along the locus of a fine bonding surface. For example, as shown in FIGS. 7B and 7C, the width of the joint surface H1602 and the ink flow path H1601 of the ink jet recording head is very narrow and has a fine structure. Therefore, as shown in FIG. 9B, the method of irradiating laser light while avoiding the ink flow path H1601 is not suitable because it takes too much time to assemble a large number of ink jet recording heads.

  On the other hand, when the batch irradiation method is used, the time required for welding can be shortened. However, when the structure of the bonding surface is fine, it is difficult to irradiate only the bonding surface with a mask by providing a mask in a portion corresponding to a fine ink flow path.

  For example, as shown in FIG. 10B, both the contact surface 600 and the region to be the ink flow path H1601 are irradiated with laser light all together, so that the surface of the ink flow path H1601 as shown in FIG. It is conceivable that the damaged portion 620 is formed by light. The damaged portion 620 in the ink flow path H1601 has a rough surface, obstructing the flow of ink, and as a result, the reliability of the inkjet recording head H1001 may be reduced.

  In view of the problems as described above, when the members that form the ink flow path are joined by irradiating and welding the laser light including the ink flow path, the laser light in the ink flow path may be damaged. An object of the present invention is to provide a method for producing a small number of ink jet recording heads. Another object of the present invention is to easily manufacture a highly reliable head at a low cost by using the above-described ink jet recording head manufacturing method.

A liquid discharge head according to the present invention is a liquid discharge head including a liquid discharge portion having a discharge port for discharging liquid and a flow path forming member having a flow path for supplying liquid to the liquid discharge portion. ,
The flow path forming member includes a transparent member that is transparent to laser light and an absorbent member that is absorbent to laser light, and a resin that is cured by the laser light is applied to the flow path forming surface. From the state, the laser beam is collectively irradiated through the transparent member toward at least the contact portion of the transparent member and the absorbent member around the flow channel and the flow channel, It is characterized in that the liquid flow path is formed by curing the previous resin and welding the permeable member and the absorbent member.

  In the above configuration, the energy of the laser beam is used to harden the resin that is cured by the laser beam. Therefore, the laser intensity to the surface on the side of the absorbent member in the ink flow path to which the resin that is cured by the laser light is applied is also attenuated, and thus damage can be reduced. Roughness of the surface due to damage to the absorbent member side in the ink flow path by laser irradiation is also hardened by the resin, so that it does not become dust in the ink flow path. Further, since the surface of the hardened resin is smooth, the ink flow is not hindered. In addition, some outgases generated from the side of the absorbent member in the ink flow path by laser irradiation deteriorate the manufacturing environment, but the generation can be suppressed by the lid effect by the hardened resin. The ability to suppress the outgas generation can simplify the gas recovery mechanism and reduce the initial cost of the apparatus.

  Next, details of the present invention will be described in accordance with the description of the embodiments.

  The liquid discharge head used in the present embodiment will be described using a general ink jet recording head as an example. The ink jet recording head has at least an ejection port for ejecting ink and an ink flow path for supplying ink in communication with the ejection port. As an example, an ink jet recording head, which is one constituent element of a recording head cartridge, will be described with reference to FIG.

  As shown in FIG. 5A, the recording head cartridge 10 includes an inkjet recording head 20 and an ink tank 40 that is detachably attached to the inkjet recording head 20.

  The recording head cartridge 10 is fixedly supported by positioning means and electrical contacts of a carriage (not shown) installed in an ink jet recording apparatus (not shown, hereinafter referred to as a recording apparatus), and is attached to and detached from the carriage. It is possible.

  The ink jet recording head 20 drives the recording element in accordance with an electrical signal sent from the recording apparatus, and thereby discharges ink supplied from the ink tank 40 containing ink from an ejection port provided in the recording element substrate H1101. . Examples of the recording element include a heating resistor element and a piezo element. Here, a recording element using a heating resistor element will be described.

  FIG. 5B is an exploded perspective view of the ink jet recording head 20 shown in FIG. The ink jet recording head 20 includes a recording element unit 300 and a tank holder unit 200 each including an electric wiring substrate 340 and a recording element substrate H1101.

  The electrical wiring board 340 includes a connection terminal 341 for electrical connection with the recording apparatus, an electrode terminal (not shown) for electrical connection with the recording element substrate H1101, and a wiring for connecting the connection terminal 341 and the electrode terminal. And an opening for incorporating the printing element substrate H1101.

  The electrical wiring board 340 and the recording element board H1101 are connected as follows, for example. After applying a thermosetting adhesive resin having conductivity to the electrode portion of the recording element substrate H1101 and the electrode terminal of the electric wiring substrate 340, the electrode portion and the electrode terminal are heated and pressurized together with a heat tool to electrically Connect all at once. In addition, the electrical connection part of an electrode part and an electrode terminal is protected from the corrosion by ink, and external impact by sealing with a sealing agent.

  FIG. 6 is a perspective view, partly cut away, for explaining the configuration of the recording element substrate H1101 as an ink ejection part (liquid ejection part) for ejecting ink.

  The recording element substrate H1101 has an ejection port H1107 for ejecting ink and an ink supply port H1102 for communicating with the ejection port and supplying ink to the ejection port, and the ejection port is formed in the ejection port forming member H1106. The ink supply port is formed in the silicon substrate H1110.

  The silicon substrate H1110 has a thickness of 0.5 mm to 1.0 mm, and an ink supply port H1102 is formed by anisotropic etching. Further, a heating resistor element H1103 is formed on the silicon substrate H1110, and the discharge port H1107 is formed on the silicon substrate 1110 by using a photolithography technique so that the heating resistor element H1103 and the discharge port H1107 correspond to each other. Is done. Further, bumps H1105 such as Au are provided on the silicon substrate H1110 as electrode portions for supplying electric signals and electric power for driving the heating resistor elements H1103.

  Next, the tank holder unit 200 having the features of the present invention will be described in detail with reference to FIG.

  As shown in FIG. 5B, the tank holder unit 200 includes a tank holder 210 having a first flow path forming member 211 and a second flow path joined to the tank holder 210 to form an ink flow path. And a forming member 220.

  In the embodiment of the present invention, the first flow path forming member 211 is formed integrally with the tank holder 210, but the first flow path forming member 211 is formed separately from the tank holder 210. The forming member 211 may be attached.

  As shown in FIG. 5B, a groove forming the ink flow path 224 may be formed in the first flow path forming member, or a groove may not be formed. Since the first flow path forming member and the second flow path forming member are joined to form the ink flow path 224, one or both of the first and second flow path forming members are appropriately provided. What is necessary is just to provide the groove | channel for forming an ink flow path.

  In order to weld and join the first flow path forming member 211 and the second flow path forming member 220 with laser light, either one of the flow path forming members has transparency to the laser light. The other flow path forming member needs to have absorptivity with respect to the laser beam.

  In the embodiment of the present invention, from the viewpoint of being able to easily irradiate laser light, the second flow path forming member 220 is a transmissive member having transparency to the laser light, and absorbs the laser light. The absorbent member having the first flow path forming member 211 was used. It is possible to appropriately change which channel forming member has permeability and absorptivity.

  In the present invention, the transmissive member having transparency to the laser light means a member having a transmittance of 30% or more when the member having a thickness of 2.0 mm is irradiated with the laser light. Moreover, the absorptive member which has absorptivity with respect to a laser beam in this invention means a member with an absorption factor of 90% or more when a 2.0-mm-thick member is irradiated with a laser beam. By using a member having the above-described transmittance and absorptivity, laser welding between the transmissive member and the absorptive member becomes possible.

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

  A first embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 2 is a perspective view showing a process of attaching the second flow path forming member 220 to the tank holder 210 in which the first flow path forming member 211 is formed. FIG. 2A shows a process of preparing the second flow path forming member 220 and the first flow path forming member 211 integrally formed with the tank holder 210 and bringing them into contact with each other. 2B, after the step of FIG. 2A, the second flow path forming member 220 is pressed by the pressing jig 53 that can irradiate the laser beam to the area around the ink flow path. 1 shows a step of bringing the first flow path forming member 211 and the second flow path forming member 220 into close contact with each other and irradiating the laser beam from the laser irradiation machine 51.

  FIG. 2C shows a state where the second flow path forming member 220 and the first flow path forming member 211 are joined (tank holder unit 200).

  1 is a cross-sectional view of FIG. 2, and each of (a) to (c) of FIG. 1 corresponds to (a) to (c) of FIG. 2. As shown in FIG. 1A, in the first embodiment, in order to absorb the laser beam irradiated toward the ink flow path 224, a resin 225 that can be cured by the laser beam is inserted. A thermosetting epoxy resin was used as the resin 225.

  A recess was formed in the tank holder 210, and the resin was held there by supplying the resin with a dispenser. From that state, a tank holder 210 and a second flow path forming member 220 were prepared and irradiated with laser light as shown in FIG. As the laser light, a semiconductor laser having a wavelength of 880 nm was used. Although the tank holder 210 is a member that absorbs laser light, the laser light that travels toward the ink flow path 224 is attenuated by the resin 225, so that damage to the surface that forms the ink flow path is reduced. . Depending on the amount of the resin 225, some of the nodal surface 223 around the ink flow path overflows, but the nodal surface 223 spreads very thinly, and due to surface tension, the first flow path forming member 211 and the The second flow path forming member 220 is temporarily joined.

  The joint surface 223 around the ink flow path may contain a very thin resin, but it is a resin that hardens with laser light, so it exhibits a binding effect and contributes to an increase in bonding reliability. To do. Therefore, as shown in FIG. 1C, the first forming member 211 and the second forming member 220 are joined (230 is a joining portion) while the cured resin is held in the ink flow path.

  Since the surface of the resin 225 hardened in the ink flow path is smooth, the ink flow was not hindered. Further, the laser irradiation in the ink flow path showed slight damage, but it was hardened in the resin and did not affect printing. When an ink jet recording head was actually made and printed, good printing could be obtained.

  In the configuration in which the resin 225 is not placed in the ink flow path, when laser welding was performed, a damaged portion such as a resin burned was observed on the surface of the ink flow path. In the case of an ink jet recording head, there is a problem in that it becomes dust depending on the printing environment and the like, resulting in defective printing. In addition, the flowability of the ink was made uneven, and the print quality was slightly affected.

  In order to accelerate the curing of the resin 225, for example, carbon black particles that generate heat by laser light may be mixed into the resin 225. Since the particles are hardened in the resin by being cured, they do not affect the ejection.

  As a method for holding the resin, it is not essential to form a recess in the first flow path forming member 211 having absorptivity with respect to the laser beam. For example, as shown in FIG. 3, the second flow path forming member 220 that transmits laser light may have an ink flow path shape, and the first flow path forming member 211 may hold the resin 225. In FIG. 3, reference numeral 213 denotes a resin holding unit that serves as a surface that forms an ink flow path.

  The resin holding part 213 was subjected to corona treatment so that the surface energy was larger than that other than the resin holding part. Thereby, since the flow path forming part of the first flow path forming member 211 has a large surface energy, it becomes a hydrophilic surface with respect to the surrounding part that is not so. Therefore, as in the first flow path member of FIG. 3, even if the resin is applied to the flat portion with a dispenser, the flow path forming portion (resin holding portion 213) of the first flow path forming member 211 is also used. ) Can hold the resin. From such a state, a tank holder 210 and a second flow path forming member 220 were prepared as shown in FIG. Even in this case, the same ink jet recording head as in the first embodiment could be obtained.

  In order to make it easier to hold the resin 225 on the resin holding part 213, the contact face 223 is subjected to a water repellent treatment so as to increase the difference in surface energy between the contact face 223 around the ink flow path and the resin holding part 213. You may do. Further, in order to make the movement of the resin easier, the contact surface may be mirror-finished.

  Applying the mirror finish is because the resin 225 is thinner and spreads on the contact surface 223, and therefore, the first flow path forming member 211 and the second flow path forming member 220 due to the solid surface tension in the first embodiment are combined. The temporary joining force also becomes stronger. In addition, since the mirror surface processing increases the actual bonding area with the second flow path forming member 220, the effect of increasing the bonding force after laser welding was also confirmed.

  In order to hold the resin 225, a resin holding shape 226 as shown in FIG. In this case, as shown in FIG. 4 (a), the resin 225 holds water droplets between the holding shapes, and the second flow path forming member 220 is provided with a flow path portion, as shown in FIG. 4 (b). 210 and the second flow path forming member 220 are prepared, and laser bonding is performed by irradiating laser light. Even with this method, an ink jet recording head with little damage in the ink flow path could be produced.

  In the second embodiment, the resin is applied by a dispenser. However, the resin may be transferred to a planar portion and supplied as in the first flow path member of FIG. Even in this case, an ink jet recording head with little damage in the ink flow path could be produced.

It is explanatory drawing of 1st Embodiment which is an example of this invention. It is a schematic diagram which shows the process at the time of laser welding the inkjet recording head of one Embodiment of this invention. It is explanatory drawing of 2nd Embodiment which is an example of this invention It is a figure which shows the other form in 2nd Embodiment which is an example of this invention. It is a figure which shows the general inkjet recording head which can apply this invention. It is a figure which shows the recording element board | substrate which comprises a general inkjet recording head. It is explanatory drawing of the conventional common inkjet recording head. It is explanatory drawing of the conventional laser welding method. It is explanatory drawing of the laser welding method of a scanning system. It is explanatory drawing of the laser welding method of a batch irradiation system.

Explanation of symbols

20 Inkjet recording head 51 Laser irradiator 211 First flow path forming member 213 Resin holding portion 220 Second flow path forming member 223 Current surface around ink flow path 224 Ink flow path 225 Resin 226 Resin holding shape

Claims (7)

A liquid discharge section having a discharge port for discharging liquid;
A flow path forming member having a flow path for supplying a liquid to the liquid discharge section;
A liquid ejection head comprising:
The flow path forming member is:
A transmissive member that is transmissive to laser light and an absorbent member that is absorbent to laser light,
From the state where a resin that is cured by laser light is applied to the flow path forming surface
By irradiating laser light through the transmissive member at least toward the contact portion between the permeable member and the absorbent member around the flow path and the flow path, Curing the permeable member and the absorbent member,
An ink jet recording head characterized by forming a liquid flow path.   The ink jet recording head according to claim 1, wherein the resin cured by the laser beam is a thermosetting resin.   3. The ink jet recording head according to claim 2, wherein the resin cured by the laser beam is mixed with carbon particles or particles that absorb the laser beam and generate heat.   4. The ink jet recording head according to claim 1, wherein the flow path forming surface of the absorbent member has a surface energy larger than a contact surface around the flow path. 5.   The ink jet recording head according to claim 1, wherein a flow path forming surface of the absorbent member has a concave shape.   6. The ink jet recording head according to claim 1, wherein a concave portion is formed around a flow path forming surface of the absorbent member.   The ink jet recording head according to claim 1, wherein the peripheral contact surface is mirror-finished.

Images