JP2007296775A - Inkjet recording head and inkjet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive inkjet recording head which can prevent a poor printing due to contaminants while ensuring a non-degradation of printing grace and high reliability. <P>SOLUTION: The inkjet recording head includes a liquid discharge substrate which is equipped with an ink passage communicating to a discharge port for discharging an ink and an energy generation means for generating an energy to discharge the ink from the discharge port, an ink supply member which forms an ink supply passage for feeding the ink to the passage and supports the liquid discharge substrate, and an electrical wiring board 3 for applying an electric control signal and a driving electric power to the liquid discharge substrate. The liquid discharge substrate is joined to the ink supply member across the electrical wiring board. A filter provided with a plurality of openings enabling the ink to pass and whose maximum opening area is smaller than the cross-sectional area of the ink passage is formed between the ink supply passage and the ink passage in the electrical wiring board. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an inkjet recording head, a method for manufacturing the inkjet recording head, and an inkjet recording apparatus.

  The ink jet recording apparatus is a so-called non-impact recording type recording apparatus, and is capable of recording on various recording media at high speed and hardly causes noise during recording. For this reason, the ink jet recording apparatus is widely used as an apparatus that bears a recording mechanism such as a printer, a word processor, a facsimile machine, and a copying machine.

  As a typical ink discharge method in this ink jet recording apparatus, there is a method using an electrothermal conversion element. In this method, a minute droplet is ejected from a minute ejection port to perform recording on a recording medium. In general, an inkjet recording nozzle for forming a droplet and this head are used. And a supply system for supplying ink.

  An ink jet recording head using an electrothermal conversion element is provided with an electrothermal conversion element in a recording liquid chamber, and gives thermal energy to the recording liquid by applying an electric pulse serving as a recording signal to the recording liquid phase. The bubble pressure at the time of foaming (boiling) of the recording liquid caused by the change is used for ejecting recording droplets. Furthermore, in the case of an ink jet recording head using an electrothermal conversion method, a recording liquid is ejected in parallel to a substrate on which electrothermal conversion elements are arranged (edge shooter) and on a substrate on which electrothermal conversion elements are arranged. There is also a method (side shooter) in which the recording liquid is ejected vertically.

  FIG. 6 shows a side sectional view of a conventional ink jet recording head cartridge 250. Here, the ink jet recording head cartridge 250 includes an ink jet recording head 201 and an ink tank 214 detachably held by a holder member 206 attached to the ink jet recording head 201.

  The ink supply member 204 is provided with a filter 209 for removing dust, bubbles, and the like in the ink on the side to be joined to the ink tank 214 that holds the ink. A path 208 is formed.

  A recording element substrate 101 having an energy generating element (not shown) that gives energy to ink in order to eject ink is bonded to an ink supply member 204 while being supported by a support member 102. In addition, an orifice plate (not shown) having an ejection port for ejecting ink and a groove portion communicating with the ejection port is formed on the surface of the recording element substrate 101 opposite to the surface supported by the support member 102. It is joined. By joining the recording element substrate 101 and the orifice plate, an ink channel (not shown) that communicates from the ink supply path 208 of the ink supply member 204 to the ejection port formed in the orifice plate is formed. The inkjet recording head 201 has a plurality of nozzles arranged in parallel, each including an ejection port, an ink flow path, and an energy generating element.

  In recent years, along with the improvement in the image quality of ink jet recording, the size of the discharge port, the ink flow path, etc. has been increasing to 20 μm or less, and the glass used for dust in the work environment and the ink supply member. In order to prevent the filler from dropping off and clogging the nozzle, as disclosed in Japanese Patent Laid-Open No. 2001-010080, ink passes between the ink supply path and the ink flow path as shown in FIG. A filter having a plurality of openings in which the opening area that is possible and has the maximum opening area is smaller than the cross-sectional area of the ink flow path has been proposed.

  Japanese Patent Publication No. 8-25272 and Japanese Patent Laid-Open No. 10-044418 disclose connection of a wiring board to a recording element substrate applied to an ink jet recording head. That is, the electrode 107 of the liquid discharge substrate 101 provided with the electrothermal conversion element and the electrode 107 on the surface side of the orifice plate 104, and the electrode of the electric wiring substrate 103 that supplies an electric control signal and driving power to the liquid discharge substrate 101 108 are electrically connected to each other by intermetallic bonding using ILB (Inner Lead Bonding) or thermocompression bonding using anisotropic conductive bonding. Furthermore, in products represented by printers and the like, the connection portion is covered with a sealing material 110 in order to protect it from ink and to protect it from a wiping operation by a rubber blade that removes dust such as ink droplets and paper dust. ing. Further, the supporting member 102 that holds the liquid discharge substrate 101 with the adhesive 210 and supplies the ink has a thermal conductivity equivalent to that of the liquid discharge substrate 101 such as alumina so that the ink discharge performance does not deteriorate due to the temperature rise of the liquid discharge substrate. It is made of a material having a rate.

  The portion where the connection electrode portion of the liquid discharge substrate and the electric wiring substrate is sealed with the sealant will protrude from the surface, and it is necessary to take a gap between the head and the recording medium by the amount of the protrusion, Reduces the accuracy of ink landing on the recording medium. Further, the protruding portion may cause an adverse effect on wiping with a rubber blade for removing dust such as ink droplets and paper dust adhering to the surface, which in turn adversely affects printing. In recent years, in order to support high-speed printing, the number of nozzles (ink discharge ports) and heat conversion elements of the liquid discharge substrate has increased, and the number of electrodes tends to increase. In addition, the area of the protruding portion of the sealing material is limited by the direction of wiping with the rubber blade, and many products are connected to the short side of the liquid discharge substrate at high density, from the electrode to the heat conversion element. The length of the power supply wiring differs greatly between the heat conversion element close to the electrode and the heat conversion element far from the electrode. In order to make the wiring resistance uniform, it is necessary to widen the power supply wiring far away. For this reason, the area occupied by the power supply wiring increases, leading to an increase in the size of the liquid discharge substrate, which hinders low cost.

In addition, a liquid discharge substrate including energy generating means for generating energy used to discharge liquid from the liquid discharge port in accordance with an electrical signal on the front surface side, a liquid discharge substrate having a liquid supply port and an electrode on the back surface side, A recording head comprising: an electric wiring substrate that supplies an electric control signal and driving power to a liquid discharge substrate; and a holding member that holds the liquid discharge substrate and supplies liquid. An electrode in which an electrode and an electrode of the electric wiring board are electrically connected and the outer periphery of the liquid supply port is sealed has been proposed.
Japanese Patent Laid-Open No. 2001-10080 Japanese Patent Publication No. 8-25272 Japanese Patent Laid-Open No. 10-44418

  However, the provision of a filter between the ink supply path and the ink flow path has a problem in that cleaning and assembly costs increase as the number of parts increases.

  An object of the present invention is to solve the above-described problems and to provide a highly reliable and inexpensive ink jet recording head that does not deteriorate print quality. Furthermore, it is providing the inkjet recording device using the recording head.

  In order to achieve the above object, the recording head according to claim 1 is provided with an energy generating means for generating energy for discharging ink from the discharge port, wherein an ink flow path communicating with the discharge port for discharging ink is formed. A liquid discharge substrate, an ink supply path for supplying ink to the ink flow path, and an ink supply member for supporting the liquid discharge substrate; and supplying an electric control signal and driving power to the liquid discharge substrate. An electric wiring board, and the liquid discharge board is bonded to the ink supply member with the electric wiring board interposed between the ink supply path and the ink flow path. A filter is formed in which a plurality of openings that allow ink to pass and have a maximum opening area smaller than the cross-sectional area of the ink flow path are formed.

  The recording head according to claim 2, wherein the electric wiring board on which the filter is formed is a flexible printed wiring board, and the plurality of openings are formed in a base film or a cover film of the electric wiring board. And

  The recording head according to claim 3 has an electrode on the same side as the ink ejection surface of the liquid ejection substrate, and the electrode of the liquid ejection substrate and the electrode of the electrical wiring substrate are electrically connected by wire bonding. It is characterized by.

  The recording head according to claim 4, wherein an electrode is provided on a surface side of the liquid discharge substrate facing the ink discharge surface, and the electrode of the liquid discharge substrate and the electrode of the electric wiring substrate are electrically connected, and the electrode and the electrode The outer periphery of the ink flow path is sealed.

  According to a fifth aspect of the present invention, the plurality of openings are formed by laser processing.

  According to a sixth aspect of the present invention, the plurality of openings are formed by pressing.

  According to a seventh aspect of the present invention, there is provided a liquid ejection apparatus comprising: an ink jet recording head; and a recording medium transport unit that transports a recording medium that receives the liquid ejected from the ink jet recording head.

(Action)
In the present invention configured as described above, by providing a filter in which an electric wiring board is processed between the ink supply path and the ink flow path, it is possible to improve print quality due to dust without adding new parts. Since the decrease can be prevented, an increase in cost can be suppressed. Moreover, since the filter processing of the electric wiring board can be performed simultaneously with the drilling of the electrodes of the electric wiring board, no additional process is required.

  Further, by using a liquid discharge substrate having an electrode on the back side, the electrode sealing portion does not protrude from the surface, and the landing accuracy of the ink on the recording medium is improved.

  As described above, according to the present invention, a filter that does not allow dust or the like to block the ink flow path to pass through the ink supply path from the ink supply path to the ink flow path is provided in the electrical wiring board. Therefore, dust and glass filler in the ink supply path can be prevented from entering the ink flow path without additional parts. Therefore, clogging of the ink flow path can be prevented.

  Further, according to the present invention, in the ink jet recording head, the electrode of the liquid discharge substrate and the electrode of the electric wiring substrate are electrically connected, and the outer periphery of the liquid supply port is sealed, so that the seal protruding from the surface is provided. Since there is no stop material, the distance between the head and the recording medium can be determined by the distance from the surface to the recording medium, the printing quality is improved, and there is also a negative effect when cleaning the orifice surface with a rubber blade. As a result, durability is improved.

  In addition, since there is no sealing material protruding on the surface, there is no restriction on the connection portion depending on the wiping direction of the rubber blade, and a low price due to low density connection is possible.

  Furthermore, since the electrode of the liquid discharge substrate and the electrode of the electric wiring substrate are electrically connected by solder and the outer periphery of the liquid supply port is sealed with a sealing material, general flip chip mounting can be used. Excellent productivity and cost reduction.

  Furthermore, the electrode of the liquid discharge substrate and the electrode of the electric wiring substrate are electrically connected by a thermosetting adhesive, and the outer periphery of the liquid supply port is sealed with a sealing material, so that it takes several seconds to several tens of seconds. Since connection is possible in a short time, throughput during production is improved and production cost is reduced.

  Furthermore, by adjusting the application amount of the thermosetting adhesive, only the thermosetting adhesive is used, and the electrical connection between the recording element substrate and the electric wiring substrate and the ink supply port of the recording element substrate and the ink holding member are adhered and sealed. Is possible.

  Furthermore, the reliability of electrical connection improves by making the electrical connection through the conductive particles using a thermosetting adhesive or an anisotropic conductive adhesive containing the conductive particles.

(Example 1)
Hereinafter, an embodiment of the present invention will be described with reference to FIG.

  The ink jet recording head of the present invention includes a recording element substrate 1, a support member 2, and an electric wiring substrate 3.

  FIG. 1 shows a cross section of this example. In FIG. 1, discharge ports 5 for discharging ink are opened in a plurality of rows on the surface side of the orifice plate 4 of the recording element substrate 1, and an ink supply port 6 for supplying ink is provided below the discharge ports 5. However, the opening is opened with a length substantially equal to the length of the ejection port array, and the back surface of the recording element substrate 1 is tapered. The electrical wiring board 3 has an 18 μm thick copper foil 32 and a 25 μm thick polyimide cover film 33 formed on a 25 μm thick polyimide base film 31 with an ink supply port 39 opened. The terminals 8 laminated and provided on the copper foil 32 are gold-plated. Further, a large number of holes 40 smaller than the ejection ports 5 are provided in the mounting portion of the ink supply port 6 of the recording element substrate 1 of the cover film 33. The support member 2 has an ink supply port 9 for supplying ink to the ink supply port 6 on the back surface of the recording element substrate 1 having substantially the same dimensions as the ink supply port 6. The more holes 40 there are, the smaller the resistance during ink supply, so it is better to be closer to the cross-sectional area of the ink supply port 9 or the ink supply port 6.

  In the ink jet recording head of the present invention, the support member 2 provided with the ink supply port 9 and the recording element substrate 1 provided with the ink supply port 6 sandwich the electric wiring substrate 3 provided with a large number of holes 40 serving as filters. The ink supply port 9, hole 40, and ink supply port 6 form an ink flow path. The support member 2 and the adhesive 23 between the electric wiring board 3, the adhesive 10 between the electric wiring board 3 and the recording element board 1, and the laminate adhesive 34 of the electric wiring board 3 are both made of thermosetting epoxy resin. ing. Epoxy resins are generally less susceptible to ink and are optimal for use in ink jet recording heads. Incidentally, the laminate adhesive 34 of the electric wiring board 3 prevents the copper foil 32 from being corroded by the ink in the ink supply port 9.

  Further, the electrode 1a of the recording element substrate 1 is wire-bonded and electrically connected to the terminal 8 of the electric wiring substrate 3 by a gold wire 11, and hermetically sealed with a sealant 12, so that the electrode portion is not affected by ink. It is like.

  According to the present embodiment, by providing the hole 40 having a filter function in the cover film 33 of the electrical wiring board 3, it is possible to prevent the printing quality from being deteriorated due to dust without adding parts.

  In addition, the hole 40 can be punched in the same manner as in the step of drilling the cover film 33. In the case of press drilling, the drilling cost is about the cost of the mold, but the mass productivity of 50 μm or less is low. On the other hand, if a YAG laser, an excimer laser, or the like is used, a large number of small holes of 20 μm or less can be formed at the same time.

(Example 2)
In the above embodiment, the small hole 40 used as a filter is provided in the cover film 33, but in FIG. 2, it is provided in the base film 31. According to this method, the adhesive 10 between the electric wiring substrate 3 and the recording element substrate 1 is stopped at the edge of the opening 35 of the cover film 33 that becomes the mounting portion of the ink supply port 6 of the recording element substrate 1. However, the hole 40 is not blocked.

Example 3
FIG. 3 shows an enlarged cross-sectional view of the connecting portion by soldering of the back electrode of this embodiment. In FIG. 3, discharge ports 5 for discharging ink are opened in a plurality of rows on the surface side of the orifice plate 4 of the recording element substrate 1, and an ink supply port 6 for supplying ink is provided below the discharge ports 5. However, the opening is opened with a length substantially equal to the length of the ejection port array, and the back surface of the recording element substrate 1 is tapered. The back electrode 7 of the recording element substrate 1 is connected to a heater (not shown) inside the recording element substrate 1 by the through electrode 20 and is electrically connected to the terminal 8 of the electrical wiring substrate 3. In this embodiment, this connection is performed by so-called flip chip mounting such as solder reflow or thermocompression bonding by the solder bumps 18 on the terminals 8. The support member 2 has an ink supply port 9 for supplying ink to the ink supply port 6 on the back surface of the recording element substrate 1. The outer periphery of the back electrode 7 and the ink supply port 6 on the back surface of the recording element substrate 1 is bonded and sealed to the outer periphery of the ink supply port 9 of the support member 2 by a sealing material 12.

  Unlike the conventional ink jet recording head that is connected by the upper surface electrode of the recording element substrate and seals the connecting portion, the structure of the present invention described above has no sealing material protruding on the surface. The interval can be determined by the distance from the orifice surface to the recording medium. Furthermore, no harmful effects are caused when the orifice surface is cleaned by the rubber blade.

  In addition, since there is no sealing material protruding on the surface, there is no restriction on the connecting portion depending on the wiping direction of the rubber blade. For this reason, the back electrodes are arranged at a low density, and connection by inexpensive equipment is possible, so that the cost can be reduced.

  Furthermore, since general flip chip mounting can be used, the productivity is excellent and the cost can be reduced.

Example 4
FIG. 4 is an enlarged view of a connection portion by the anisotropic conductive adhesive 15 including conductive particles of the back electrode. In FIG. 4, the bumps 18 are formed on the terminals 8 of the electric wiring board 3, the back surface electrode 7 of the recording element board 1, or both. The back electrode 7 of the recording element substrate 1 and the terminal 8 of the electric wiring substrate 3 are electrically connected through the bumps 18 and the conductive particles of the anisotropic conductive adhesive 15 and are compressed and fixed by the anisotropic conductive adhesive 15. Has been. The outer periphery of the back electrode 7 and the ink supply port 6 on the back surface of the recording element substrate 1 is bonded and sealed to the outer periphery of the ink supply port 9 of the ink holding member 2 by a sealing material 12.

  In the configuration of the present embodiment, the same effects as those of the third embodiment can be obtained. Furthermore, since connection is possible in a short time of several seconds to several tens of seconds, throughput during production is improved and production cost is reduced.

  Note that productivity is improved by directly electrically connecting the back electrode 7 of the recording element substrate 1 and the bumps 18 on the terminals 8 of the electric wiring substrate 3 using a thermosetting adhesive that does not contain conductive particles. . For example, when TMP0015A manufactured by Toshiba Chemical was used as the thermosetting adhesive, connection and fixation were possible in several seconds to several tens of seconds.

  Furthermore, by adjusting the application amount of the thermosetting adhesive, only the thermosetting adhesive is used, and the electrical connection between the recording element substrate and the electric wiring substrate and the ink supply port of the recording element substrate and the ink holding member are adhered and sealed. It is also possible to do.

  On the other hand, this embodiment also has the same effect as that of the third embodiment.

(Example 5)
The ink jet recording head of the present invention has been described by taking the above embodiment as an example. Hereinafter, an ink jet recording apparatus to which the ink jet recording head of the present invention is applied will be described. Note that symbols used in the following description are representatively used in the first embodiment.

  An external view of an example of an ink jet recording apparatus to which the ink jet recording head 16 is applied is shown in FIG.

  A lead screw 552 having a spiral groove 553 is rotatably supported on the main body frame 551. The lead screw 552 is rotationally driven via the driving force transmission gears 560 and 561 in conjunction with the forward / reverse rotation of the drive motor 559. In addition, a guide rail 554 that slidably guides the carriage 555 is fixed to the main body frame 551. The carriage 555 is provided with a pin (not shown) that engages with the spiral groove 553. By rotating the lead screw 552 by the rotation of the drive motor 559, the carriage 555 reciprocates in the directions of the arrows a and b shown in the figure. It can be done. The paper pressing plate 572 presses the recording medium 590 against the platen roller 573 over the moving direction of the carriage 555.

  An ink jet recording head cartridge 580 is mounted on the carriage 555. The ink jet recording head cartridge 580 is obtained by integrating the ink jet recording head 16 described above with an ink tank IT. The ink jet recording head cartridge 580 is fixedly supported on the carriage 555 by positioning means and electrical contacts provided on the carriage 555 and is detachable from the carriage 555.

  The photocouplers 557 and 558 constitute home position detecting means for confirming the presence of the lever 556 of the carriage 555 in this region and performing reverse rotation of the rotation direction of the drive motor 559 and the like. A cap member 567 that caps the front surface of the ink jet recording head 16 (the surface on which the ink discharge ports 24 a are formed) is supported by a support member 562, further includes suction means 566, and is provided with an ink jet recording head via an opening 568 in the cap. 16 suction recovery is performed. A support plate 565 is attached to the main body support plate 564, and the cleaning blade 563 slidably supported on the support plate 565 is moved in the front-rear direction by a driving means (not shown). It goes without saying that the form of the cleaning blade 563 is not limited to that shown in the figure, and a known one can be applied. The lever 570 is for starting the suction recovery operation of the ink jet recording head 16, and moves with the movement of the cam 571 in contact with the carriage 555, and the driving force from the driving motor 559 is known such as gear switching or latch switching. The movement is controlled by the transmission means.

  These capping, cleaning, and suction recovery processes are performed at corresponding positions by the action of the lead screw 552 when the carriage 555 moves to the home position side region. Any desired application can be applied to this example as long as a desired operation is performed at a known timing.

  The ink jet recording apparatus described above includes a recording signal supply unit that supplies a recording signal for driving the heater of the mounted ink jet recording head 16 to the ink jet recording head 16, and includes a control unit that controls the operation of the ink jet recording apparatus. ing.

  Since the ink jet recording apparatus of the present invention is equipped with the ink jet recording head 16 described above, the ink discharge is stable, and as a result, a recording apparatus with little deterioration in image quality can be achieved. In the ink jet recording apparatus of the present invention, the example in which the ink jet recording head cartridge 580 is detachably mounted on the carriage 555 is shown. However, the present invention is not limited to this, and the ink jet recording head 16 is integrated with the carriage 555 and only the ink tank is provided. It is good also as a structure mounted so that attachment or detachment is possible.

The cross section of Example 1 is shown. 6 is a cross-sectional view of Example 2. FIG. It is a cross-sectional enlarged view of the connection part by the solder | pewter of the back surface electrode of a present Example. It is an enlarged view of the connection part by the anisotropic conductive adhesive 15 containing the electroconductive particle of a back surface electrode. 1 is an external view of an ink jet recording apparatus to which an ink jet recording head of the present invention is applied. This is a conventional example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recording element board | substrate 2 Support member 3 Electrical wiring board 4 Orifice plate 5 Ejection port 6 Ink supply port of recording element board 7 Back surface electrode 8 Terminal of electrical wiring board 9 Ink supply port of ink holding member 10 Adhesive 11 Gold wire 12 Sealing Stop material 15 Anisotropic conductive adhesive 18 Solder bump 18a Bump 23 Adhesive 31 Base film 32 Copper foil 33 Cover film 34 Laminate adhesive 40 Hole

Claims (7)

An ink channel that communicates with an ejection port that ejects ink is formed, and a liquid ejection substrate that includes energy generation means for generating energy for ejecting ink from the ejection port, and supplying ink to the ink channel An ink supply member formed with an ink supply path and supporting the liquid ejection substrate;
An electric wiring board for supplying an electric control signal and driving power to the liquid discharge board;
In an inkjet recording head having
The liquid discharge substrate is bonded to the ink supply member with the electric wiring board interposed therebetween, and the ink can pass through the electric wiring board between the ink supply path and the ink flow path and is maximized. An ink jet recording head, comprising: a filter having a plurality of openings in which an opening area is smaller than a cross-sectional area of the ink flow path.   The electrical wiring board on which the filter is formed is a flexible printed wiring board, and the plurality of openings are formed in a base film or a cover film of the electrical wiring board. Inkjet recording head.   2. The electrode according to claim 1, wherein an electrode is provided on the same side as an ink discharge surface of the liquid discharge substrate, and the electrode of the liquid discharge substrate and the electrode of the electric wiring substrate are electrically connected by wire bonding. The ink jet recording head according to claim 2.   There is an electrode on the side of the liquid discharge substrate facing the ink discharge surface, the electrode of the liquid discharge substrate and the electrode of the electrical wiring substrate are electrically connected, and the outer periphery of the electrode and the ink flow path is sealed. The ink jet recording head according to claim 1, wherein the ink jet recording head is provided.   The ink jet recording head according to claim 1, wherein the plurality of openings are laser processed.   The inkjet recording head according to claim 1, wherein the plurality of openings are pressed.   5. A liquid ejection apparatus comprising: the ink jet recording head according to claim 1; and a recording medium transport unit that transports a recording medium that receives liquid ejected from the ink jet recording head.

Images