JP6409277B2 - Liquid ejection device - Google Patents

Description

  The present invention relates to a liquid ejection device that ejects liquid.

  A heat source driving type ink discharge head used in an inkjet printer or the like generates bubbles in ink using a heat source and discharges ink droplets by the expansion force of the bubbles. An example of such a heat source driving type ink discharge head is disclosed in Japanese Patent Application Laid-Open No. H10-228707.

  In the ink discharge head described in Patent Document 1, nozzles that discharge ink are arranged in a staggered pattern and at a high density. Therefore, there are two types, a short distance and a long distance of the flow path for supplying ink to the nozzle. In a flow path with a short distance, the flow path resistance through which ink flows becomes small. Therefore, a resistance member is provided at a position facing the entrance of the flow path, and the resistance of the flow path is increased. Therefore, in the ink ejection head described in Patent Document 1, the difference in the landing position of the ink ejected from each nozzle is prevented by eliminating the difference in ink filling into each ink chamber due to the difference in flow path resistance. ing.

JP 2006-315395 A

  However, in the conventional ink ejection head, since the resistance member is provided at a position facing the entrance of the flow path, the ink flow to the adjacent flow path cannot be reduced by the resistance member. Accordingly, when ink is continuously ejected from a certain nozzle, the ink filling into the ink chamber of the nozzle adjacent to the nozzle is affected. As a result, there is a problem that crosstalk occurs or ink filling properties deteriorate.

  An object of the present invention is to solve the above-described problems, and an object of the present invention is to provide a liquid ejection apparatus that can reduce the occurrence of crosstalk and can improve the liquid filling property.

A liquid ejection apparatus according to a first aspect of the present invention includes a planar substrate, a plurality of energy generating elements that are provided on one surface of the substrate and impart energy to the liquid for ejecting the liquid, and the substrate A nozzle layer having a plurality of discharge holes for discharging the liquid, facing the one surface, and a plurality of flows each defining a liquid chamber containing the energy generating element between the one surface and the nozzle layer. A liquid supply port that communicates a road wall with a first opening formed at a position spaced apart from the energy generating element on the one surface and a second opening formed on the other surface of the substrate; and the liquid A liquid flow path for supplying the liquid supplied to the chamber from the first opening, and an end of the first opening corresponding to one end of the flow path wall, extending to the center side of the first opening. liquid discharge apparatus der provided with a protrusion Te, between the nozzle layer and the protrusions, the pillar is formed only on the liquid ejecting apparatus for ejecting relatively small liquid discharge frequency and providing a said column.

In the liquid ejection device, the inflow of the liquid into the adjacent liquid flow path can be reduced by the protruding portion, so that crosstalk can be reduced and the liquid filling property can be improved. In a liquid discharge apparatus other than a liquid with a relatively low discharge frequency, since there is no column, filling of the liquid is not delayed. Therefore, a liquid ejecting apparatus other than a liquid with a relatively low ejection frequency can eject liquid earlier than a color liquid ejecting apparatus.

  The width of the liquid channel may be wider than a distance between a pair of adjacent channel walls in which the liquid channel is formed and the corresponding protrusions. In this case, the gap between the protrusions adjacent to each other serves as a dust filter.

  The interval between the columns adjacent to each other may be narrower than the width of the liquid channel. In this case, the gap between the columns adjacent to each other serves as a dust filter.

2 is a plan view of the ink discharge head 100. FIG. 2 is a partially enlarged view of a plane of the ink discharge head 100. FIG. FIG. 3 is a cross-sectional view of the ink discharge head 100 in the direction of the arrow in the X-X line of FIGS. 1 and 2. 5 is an explanatory diagram of a method for manufacturing the ink discharge head 100. FIG. FIG. 5 is an explanatory diagram (continuation of FIG. 4) of the method for manufacturing the ink discharge head 100. FIG. 6 is an explanatory diagram (continuation of FIG. 5) of the method for manufacturing the ink discharge head 100. 3 is a partially enlarged view of a plane of the ink discharge head 101. FIG. 3 is a partially enlarged view of a plane of the ink discharge head 102. FIG. FIG. 9 is a cross-sectional view of the ink discharge head 102 in the direction of the arrow in the X1-X1 line of FIG. 3 is a partially enlarged view of a plane of the ink discharge head 103. FIG. 2 is a partially enlarged view of a plane of the ink discharge head 104. FIG. 3 is a partially enlarged view of a plane of the ink discharge head 105. FIG.

  Hereinafter, a first embodiment embodying the present invention will be described with reference to the drawings. First, the configuration of the ink ejection head 100 according to the first embodiment of the present invention will be described with reference to FIGS. In the following embodiments, an example of the liquid is ink, and an example of the liquid ejection device is the ink ejection head 100. The drawings are schematic diagrams for easy understanding of the structure, and the ratio of dimensions is different from that of the actual ink discharge head 100. For example, the thickness of the substrate 11 is actually larger than the ratio shown in the figure, and the width of the ink supply port 2 shown in FIGS. 2 and 3 is wider than the ratio shown in the figure.

[Configuration of Ink Ejection Head 100]
As shown in FIG. 1, the ink discharge head 100 has a plurality of ink discharge holes 1 aligned in one direction. Each of the ink ejection holes 1 communicates with an individually provided ink chamber 5 (see FIGS. 2 and 3). As shown in FIG. 2, the ink chamber 5 is partitioned by a side wall 19A and a partition wall 19B. In the ink chamber 5, heaters 13 (see FIG. 3) functioning as energy generating elements for discharging ink are provided. Ink is supplied to the ink chamber 5 through the ink supply port 2 connected to the ink chamber 5 from the lower surface of the ink discharge head 100. A part of the ink supplied to the ink chamber 5 becomes bubbles due to the heating of the heater 13. The ink in the ink chamber 5 pushed out by the bubbles is ejected from the ink ejection hole 1.

  FIG. 3 is a cross-sectional view of the ink discharge head 100 taken along a direction orthogonal to the alignment direction of the plurality of ink discharge holes 1 (that is, the XX cross section in FIGS. 1 and 2). The layer structure of the ink ejection head 100 is mainly composed of a substrate layer 10, a barrier layer 30, and a nozzle layer 20 from the lower side shown in FIG. An ink supply port 2 is opened in the substrate layer 10. The ink supply port 2 communicates the first opening 2 </ b> B formed on the upper surface side of the substrate layer 10 and a position away from the heat generating portion of the heater 13 and the second opening 2 </ b> C formed on the lower surface side of the substrate layer 10. Ink is supplied from the lower surface of the substrate layer 10 to the ink chamber 5 defined by the nozzle layer 20 and the barrier layer 30 through the ink supply port 2. The nozzle layer 20 has ink discharge holes 1 for discharging ink. Hereinafter, each layer structure will be described.

  The substrate layer 10 is formed mainly of a substrate 11 made of silicon. An insulating layer 17 is formed on one surface (for example, the lower surface) of the substrate 11. An example of the material of the insulating layer 17 is an insulating material such as silicon dioxide. An insulating layer 12 is provided on the other surface (for example, the upper surface) of the substrate 11. An example of the material of the insulating layer 12 is an insulating material such as silicon dioxide. On the upper surface side of the insulating layer 12, a layer of the heater 13 is formed. The heater 13 is composed of a resistance layer. An example of the material of the heater 13 is a resistance heating element such as TaN or TaAl. The heater 13 is an energy generating element that gives the ink energy for discharging the ink. As shown in FIG. 3, a wiring 14 is provided on the upper surface side of the heater 13 in the portion of the substrate layer 10 facing the ink ejection hole 1. An example of the material of the wiring 14 is Al, Cu or the like. A protective layer 15 is provided on the upper surface side of the wiring 14. An example of the material of the protective layer 15 is an insulating material such as silicon nitride. A protective film 16 that prevents damage to the protective layer 15 is formed on the upper surface side of the protective layer 15 and the portion facing the ink ejection holes 1. An example of the material of the protective film 16 is a substance such as tantalum, which protects the protective layer 15 from an impact at the time of defoaming. Further, on the right end side of the upper surface of the protective layer 15, there is provided an adhesion enhancing layer 18 that closely contacts a side wall 19 </ b> A described later and the protective layer 15. A side wall 19 </ b> A is provided on the adhesion enhancing layer 18.

  As shown in FIG. 3, an insulating layer 12 is provided on the upper surface side of the substrate 11 on the left side of the ink supply port 2 in the substrate layer 10. On the upper surface side of the insulating layer 12, a layer of the heater 13 is formed. The wiring 14 is not provided on the upper surface side of the heater 13, and a protective layer 15 is provided. On the upper side of the protective layer 15, an adhesion enhancing layer 18 is provided to adhere a partition wall 19 </ b> B (described later) and the protective layer 15. As shown in FIGS. 2 and 3, the protruding portion 6 extends horizontally from the end portion of the substrate layer 10 on the ink supply port 2 side toward the center of the ink supply port 2. The protruding portion 6 is formed by protruding a portion of the substrate layer 10 where the partition wall 19B is provided in a rectangular shape in plan view. Specifically, in the substrate layer 10, the protruding portion 6 extends from the position corresponding to the end portion 19 </ b> C on the ink supply port 2 side of the partition wall 19 </ b> B (the position adjacent to the end portion 19 </ b> C) toward the ink supply port 2 side. Projecting horizontally with the plane. In the present embodiment, the protruding portion 6 is a portion where the insulating layer 12 and the protective layer 15 protrude. A columnar column 4 is formed on the protrusion 6 via an adhesion enhancing layer 18. The material of the pillar 4 is an epoxy resin as an example. The position of the column 4 is separated from the end of the partition wall 19B on the ink supply port side. A gap 3 is formed between the end of the partition wall 19B on the ink supply port side and the column 4.

  On the upper surface side of the adhesion enhancing layer 18, a side wall 19 </ b> A and a partition wall 19 </ b> B that partition the ink chamber 5 are provided. As shown in FIG. 2, the side wall 19 </ b> A extends in the longitudinal direction of the ink discharge head 100 (the front-rear direction in FIG. 2). The partition wall 19B extends in a direction orthogonal to the side wall 19A. As shown in FIG. 2, the end 19C of the partition wall 19B on the ink supply port 2 side is wide in the direction parallel to the side wall 19A. The ink chamber 5 is partitioned as a substantially rectangular parallelepiped space by the side wall 19A and the pair of partition walls 19B. Between the end portion 19C of the partition wall 19B and the end portion 19C of the adjacent partition wall 19B, an ink flow path 5A to the ink chamber 5 is formed. The material of the side wall 19A and the partition wall 19B is, for example, an epoxy resin. A barrier layer 30 is formed by the side wall 19 </ b> A, the partition wall 19 </ b> B, and the pillar 4. The term “formed on the upper surface (one surface) of the substrate 11 is formed in direct contact with the upper surface of the substrate 11, and is formed on the upper surface side of the substrate 11 with some configuration in between. It also means that. Of course, the term “formed on the lower surface (the other surface)” should be interpreted in the same manner.

  As shown in FIG. 2, the width L <b> 1 of the flow path 5 </ b> A is wider than the interval L <b> 2 between the adjacent protrusions 6 and 6. The width L1 of the flow path 5A is wider than the interval L3 between the adjacent columns 4 and 4.

  As shown in FIGS. 2 and 3, the substrate 11 has an ink supply port 2 that is an opening. The ink supply port 2 is formed in an elongated shape extending in the planar direction of the substrate 11, specifically in a rectangular shape in plan view. A plurality of ink ejection holes 1 and a plurality of heaters 13 are provided along the longitudinal direction of the ink supply port 2.

  Next, the nozzle layer 20 will be described with reference to FIG. The nozzle layer 20 extends from the upper end of the side wall 19A, the partition wall 19B, and the pillar 4 in a substantially flat plate shape in the substrate plane direction. An ink discharge hole 1 is formed at a position facing the heat generating portion 13A of the heater 13 of the nozzle layer 20. The nozzle layer 20, the side wall 19 </ b> A, the partition wall 19 </ b> B, and the pillar 4 define an ink flow path through which ink flows on the upper surface of the substrate layer 10. In the present embodiment, the side wall 19A, the partition wall 19B, and the column 4 are configured separately, but may be configured integrally. A water repellent film 21 is formed on the upper surface side of the nozzle layer 20.

[Method for Manufacturing Ink Discharge Head 100]
Hereinafter, the manufacturing process of the ink ejection head 100 will be described with reference to FIGS.

  First, as shown in FIG. 4A, a silicon substrate 11 having insulating layers 12 and 17 is prepared. The insulating layers 12 and 17 are made of, for example, silicon oxide. The insulating layers 12 and 17 are formed, for example, by thermally oxidizing the silicon substrate 11. Alternatively, an off-the-shelf substrate in which silicon oxide films are previously provided on both sides may be used. The thickness of the substrate 11 is about 625 μm, for example. Moreover, the thickness of the insulating layers 12 and 17 is about 1-5 micrometers, for example.

(Energy generating element / thin film layer forming process)
Next, as shown in FIG. 4A, the heater 13 is formed on the insulating layer 12 of the substrate 11. The heater 13 is formed, for example, by depositing a resistance heating element such as TaN or TaAl on the formation position of the heater 13 by a sputtering method so as to have a thickness of about 200 to 1000 mm. Similarly, the wiring 14 is formed by sputtering with a metal such as Al or Cu, or an alloy such as AlCu. Thereby, a wiring process is also performed together.

  Next, as shown in FIG. 4A, a protective layer 15 which is a thin film layer having ink resistance is formed so as to cover at least the heater 13 and the wiring 14 on the upper surface of the substrate 11. The protective layer 15 is obtained by depositing silicon nitride on the heater 13, the wiring 14, and the insulating layer 12 by, for example, chemical vapor deposition (plasma CVD) using plasma or sputtering. The thickness of the protective layer 15 is, for example, about 0.4 μm. Next, a protective film 16 that prevents damage to the protective layer 15 is formed on the upper surface side of the protective layer 15 and on the portion facing the ink ejection holes 1. An example of the material of the protective film 16 is a hard substance such as tantalum. The protective film 16 is formed by a sputtering method. Next, an adhesion enhancing layer 18 is formed on the protective layer 15. An example of the material of the adhesion enhancing layer 18 is the same material as that constituting the barrier layer 30.

(Barrier layer wall formation process)
Next, as shown in FIG. 4B, on the adhesion enhancing layer 18 on the substrate 11, the side wall 19A, the partition wall 19B, and the pillar 4 constituting the barrier layer 30 serving as the ink flow path wall are formed. The In the present embodiment, the side wall 19A, the partition wall 19B, and the pillar 4 are formed of a cured epoxy resin. The film thickness of the side wall 19A, the partition wall 19B, and the pillar 4 may be adjusted to be, for example, about 10-30 μm.

(Sacrificial layer formation process)
Next, as shown in FIG. 4C, a sacrificial layer 27 is formed. The sacrificial layer 27 is also formed in regions covering the side walls 19 </ b> A, the partition walls 19 </ b> B, and the top surfaces of the pillars 4. For example, the sacrificial layer 27 is formed by injecting a semi-cured resin into the space formed by the side wall 19A, the partition wall 19B, and the pillar 4 and drying it. In this embodiment, a polyimide material and photo nice of Toray Industries, Inc. are used in a semi-cured state as the semi-cured resin. Photo Nice is soluble in an alkaline solution, but insoluble in an organic solvent. The epoxy resin constituting the side wall 19A, the partition wall 19B, and the pillar 4 is cured before the sacrificial layer 27 is injected by heat or light. The epoxy resin constituting the side wall 19A, the partition wall 19B, and the pillar 4 is soluble in an organic solvent when not cured, but is insoluble in an organic solvent when cured. Therefore, no cross-mixing occurs between the side wall 19A, the partition wall 19B, the pillar 4 and the sacrificial layer 27. A novolac resin may be used as the sacrificial layer 27. As an example of the novolak resin, EP4080G and EP4050G manufactured by Asahi Organic Materials Co., Ltd. dissolved in an organic solvent such as propylene glycol monomethyl ether acetate (PGMEA) can be used. The novolak resin has extremely low solubility in xylene and toluene, but dissolves in an alkaline aqueous solution and acetone. Since the epoxy resin which comprises the side wall 19A, the partition wall 19B, and the pillar 4 is hardened | cured, it is insoluble with respect to the organic solvent. Therefore, even when novolac resin is used, cross mixing does not occur between the side wall 19A, the partition wall 19B, the pillar 4 and the sacrificial layer 27.

  Next, as shown in FIG. 4D, the sacrificial layer 27 is removed from the upper surface so that the upper surface of the sacrificial layer 27 becomes flat. Here, if the sacrificial layer 27 remains on the side wall 19 </ b> A, the partition wall 19 </ b> B, and the pillar 4, there is a possibility that the adjacent ink chambers 5 communicate with each other. Therefore, the sacrificial layer 27 is flattened until the sacrificial layer 27 and the side walls 19A, the partition walls 19B, and the pillars 4 are positioned on the same plane, in other words, until the upper surfaces of the side walls 19A, the partition walls 19B, and the pillars 4 are exposed. Is desirable. At this time, the side walls 19 </ b> A, the partition walls 19 </ b> B, and the top surfaces of the pillars 4 may be slightly removed. Note that the sacrificial layer 27 is planarized by, for example, machining such as polishing, grinding, or cutting. Alternatively, after the rough planarization by machining, fine planarization such as dissolving the sacrificial layer 27 from the upper surface by immersing the ink discharge head 100 in an alkaline solution may be performed.

(Nozzle layer formation process)
Next, as illustrated in FIG. 5A, the nozzle layer 20 is formed so as to cover the side wall 19 </ b> A, the partition wall 19 </ b> B, the pillar 4, and the sacrificial layer 27. The nozzle layer 20 is provided with an ink discharge hole 1 for discharging ink at a position facing the heat generating portion of the heater 13. The nozzle layer 20 is formed so as not to dissolve the sacrificial layer 27. For this purpose, for example, spin coating or spray coating using a solvent that does not dissolve the resin of the sacrificial layer 27 is performed. For the formation of the nozzle layer 20, for example, a mixture of an epoxy resin dissolved in a solvent such as xylene or toluene, a silane coupling agent, and a photopolymerization initiator is used. Xylene and toluene do not dissolve the above-mentioned semi-cured polyimide or novolak resin, and are therefore convenient as a solvent for the resin forming the nozzle layer 20. After application of the resin constituting the nozzle layer 20, the resin constituting the nozzle layer 20 is heated in order to improve the adhesion between the side wall 19 </ b> A, the partition wall 19 </ b> B, and the column 4 and to drive off the solvent remaining in the nozzle layer 20. The Here, in the case of coating using a solvent, if the temperature is raised too much after application, the solvent remaining in the nozzle layer 20 may dissolve the sacrificial layer 27 in some cases. Therefore, this heating temperature is set so as not to damage the sacrificial layer 27. The film thickness of the nozzle layer 20 is adjusted to 20-50 μm or the like.

  Photolithography is performed on the nozzle layer 20 thus formed, and the ink ejection holes 1 are formed. When developing the ink discharge hole 1, a solvent that does not dissolve the sacrificial layer 27, such as xylene or toluene, is used. However, the sacrificial layer 27 in the vicinity of the ink ejection holes 1 may be partially removed using PGMEA, acetone, an alkaline aqueous solution, or the like.

(Ink supply port forming process)
Next, as shown in FIG. 5B, the shape of the ink supply port 2 is patterned on the lower surface side (insulating layer 17 side) of the substrate layer 10, and chemical and physical such as wet etching and dry etching are performed. Machining such as etching or sandblasting is performed. By this processing, the ink supply port 2 is opened in the insulating layer 17 and the substrate 11 from the lower surface side to the upper surface side of the substrate layer 10. In this case, since the ink supply port 2 is opened from the lower surface side of the substrate 11 as shown in FIG. 5B, the lower opening area of the ink supply port 2 is larger than the upper opening area. Note that the opening width of the ink supply port 2 (the width in the left-right direction in FIG. 5) is, for example, about 100 μm in the case of wet etching.

  Next, as shown in FIG. 5C, a resist 22 is applied to the back side of the substrate layer 10, and the ink supply port 2, the protruding portion 6, and the flow path 5 </ b> B are patterned on the insulating layer 12 and the protective layer 15. . Next, as shown in FIG. 6A, chemical etching such as dry etching is performed from the back side of the substrate layer 10. As a result, openings are formed in the insulating layer 12 and the protective layer 15, and the ink supply port 2, the protruding portion 6, and the flow path 5B are formed as shown in FIG. Next, as shown in FIG. 6B, the resist 22 on the back surface side of the substrate layer 10 is peeled off and removed.

(Sacrificial layer removal / water repellent film process)
Thereafter, the sacrificial layer 27 is removed by dissolution with a solvent such as an alkaline solution. When the sacrificial layer 27 is composed of a novolac resin, the ink ejection head 100 is immersed in an organic solvent such as acetone or PGMEA. The sacrificial layer 27 dissolved in the solvent flows out of the ink ejection holes 1 and the ink supply ports 2, whereby the sacrificial layer 27 is removed. Thereafter, as shown in FIG. 3, a water repellent film 21 is formed on the upper surface side of the nozzle layer 20.

  As described above, in the ink ejection head 100 of the first embodiment, as shown in FIG. 2, the ink flows from the ink supply port 2 to the flow path 5 </ b> B between the protrusions 6 and 6 adjacent to each other and the columns adjacent to each other. 4 and 4, flows into the ink chamber 5 through the flow path 5 </ b> A. The ink heated by the heater 13 is discharged from the ink discharge hole 1. Thereafter, the ink passes through the flow path 5B between the protrusions 6 and 6 adjacent to each other and the columns 4 and 4 adjacent to each other from the ink supply port 2, and is further replenished to the ink chamber 5 through the flow path 5A. .

  In the ink ejection head 100 according to the first embodiment, as shown in FIG. 2, the protrusion 6 on the substrate layer 10 from the position corresponding to the end 19C on the ink supply port 2 side of the partition wall 19B, from the ink supply port 2 side. Therefore, when the plurality of ink ejection holes 1 are driven and the plurality of ink chambers 5 are filled with ink, the ink mainly passes from the supply port 2 to the flow path 5B in front of the ink chamber 5. Then, as shown by the arrow A, the ink chamber 5 is filled. Further, as indicated by an arrow B, the amount of ink charged into the ink chamber 5 from the supply port 2 in front of the ink chamber 5 adjacent to the ink chamber 5 is blocked by the protrusion 6 and decreases. Therefore, when the ink chamber 5 is filled with ink, it is difficult to affect the ink filled in the adjacent ink chamber 5. Therefore, crosstalk is reduced.

  Further, in the ink ejection head 100 of the first embodiment, as shown in FIG. 2, the columns 4 are provided so as to face the partition walls 19B. Therefore, when the ink flows from the flow path 5B of the ink chamber 5 adjacent to the ink chamber 5 as indicated by the arrow B, the flow resistance increases, so that the adjacent ink chamber 5 is hardly affected. A gap 3 is formed between the end of the partition wall 19B on the ink supply port side and the column 4. Ink flows into the flow path 5A as indicated by an arrow B through the gap 3. Accordingly, when one ink discharge hole 1 is driven, ink flowing into the ink chamber 5 flows into the flow channel 5A from the flow channel 5B and the gaps 3 and 3, so that the ink filling performance into the ink chamber 5 is improved. it can.

  As shown in FIG. 2, the width L1 of the flow path 5A is wider than the interval L2 between the adjacent protrusions 6 and 6. The width L1 of the flow path 5A is wider than the interval L3 between the adjacent columns 4 and 4. That is, the distance L2 between the protrusions 6 and 6 and the distance L3 between the columns 4 and 4 are narrower than the width L1 of the flow path 5A. Therefore, it acts as a filter for foreign matters mixed in ink between the adjacent protrusions 6 and 6 and between the adjacent columns 4 and 4.

  Next, the structure of the ink discharge head 101 according to the second embodiment of the present invention will be described with reference to FIG. Below, the point from which the ink discharge head 101 differs from the ink discharge head 100 of 1st embodiment is demonstrated. As shown in FIG. 7, in the ink ejection head 101 of the second embodiment, the cross-sectional shape of the pillar 4A is different from the ink ejection head 100 of the first embodiment. In the ink ejection head 101 of the second embodiment, the column 4A has a flat surface on the partition wall 19B side, and the ink supply port 2 side has a semi-cylindrical shape. Other structures are the same as those in the first embodiment. In the ink ejection head 101 of the second embodiment, the flow of the ink from the flow path 5B to the flow path 5A (arrow A) is the same as when the cylindrical column 4 is provided. Further, the gap 3 is a gap between the plane of the pillar 4A and the plane of the end of the partition wall 19B, and the ink flow (arrow B) is worse than the gap 3 of the ink ejection head 100 of the first embodiment. Therefore, even if the gap 3 of the ink discharge head 101 of the second embodiment is wider than the gap 3 of the ink discharge head 100 of the first embodiment, the same effect can be obtained. Therefore, it can be created even if the resolution of lithography is poor. Therefore, the difficulty of creation is reduced and the yield can be improved. Therefore, the production cost can be reduced.

  Next, the structure of the ink ejection head 102 according to the third embodiment of the present invention will be described with reference to FIGS. Hereinafter, differences between the ink discharge head 102 and the ink discharge head 100 of the first embodiment will be described. As shown in FIG. 8, in the ink discharge head 102 of the third embodiment, the protruding portion 6 is not provided, and the cross-sectional shape of the pillar 4B is different from that of the ink discharge head 100 of the first embodiment. In the ink ejection head 102 of the third embodiment, the column 4B has a flat surface on the partition wall 19B side, and the ink supply port 2 side has a spindle-shaped cross section and protrudes long on the ink supply port 2 side. Further, a column 4 </ b> C is formed between the columns 4 </ b> B and 4 </ b> B adjacent to each other downward from the nozzle layer 20 toward the ink supply port 2. The column 4C has a flat surface on the ink chamber 5 side and a semi-cylindrical shape on the opposite side. Other structures are the same as those in the first embodiment. In the ink discharge head 102 of the third embodiment, the flow of the ink from the flow path 5B to the flow path 5A can be made the same as the case where the cylindrical column 4 is provided without providing the protruding portion 6. Further, the gap 3 is a gap between the plane of the pillar 4A and the plane of the end of the partition wall 19B, and it is difficult for ink to pass through the gap 3 of the ink ejection head 100 of the first embodiment. Accordingly, the gap 3 of the ink discharge head 102 of the third embodiment can achieve the same effect even if the gap is wider than the gap 3 of the ink discharge head 100 of the first embodiment. Further, as shown in FIG. 9, the back wave, which is a wave returning from the ink chamber 5 to the flow path 5A during driving, is deflected downward as indicated by the arrow C by the column 4C, and the back wave is the flow of ink. Can be reduced.

  In the above-described embodiment, the ink discharge heads 100, 101, and 102 are examples of the “liquid discharge device”. The heater 13 is an example of an “energy generating element”. The ink chamber 5 is an example of a “liquid chamber”. The partition wall 19B is an example of the “channel wall”. The ink supply port 2 is an example of a “liquid supply port”. The channel 5A is an example of a “liquid channel”. The end portion 19C is an example of “one end portion of the flow path wall”.

  The present invention is not limited to the embodiments described so far, and various modifications and changes can be made without departing from the spirit of the present invention. An example is described below.

  The ink discharge head includes a color ink discharge head that discharges cyan (C), magenta (M), and yellow (Y) ink, and an ink discharge head that discharges black (K) ink. The column 4 may be provided only on the ink discharge head that discharges ink as described above. The ink discharge head that discharges black (K) ink may have only the protruding portion 6 as in the ink discharge head 103 shown in FIG. In this case, in the ink ejection heads other than the color (for example, black (K)), since the column 4 is not provided, the ink filling into the ink chamber 5 is not delayed. Therefore, an ink discharge head other than color (for example, black (K)) can discharge ink faster than a color ink discharge head. The color ink is an example of “a liquid with a relatively low discharge frequency”.

  Further, the opening diameter of the ink discharge hole 1 of the ink discharge head that discharges black (K) may be larger than the opening diameter of the ink discharge hole 1 of the color ink discharge head. Therefore, a large droplet can be discharged. Further, since high-speed driving is required, the ink ejection head that ejects black (K) is removed, and the column 4 is removed as in the ink ejection head 103 shown in FIG. May be.

  Further, as in the ink discharge head 104 shown in FIG. 11, the interval L4 between the columns 4D and 4D adjacent to each other may be narrower than the interval L2 between the protrusions 6 and 6 adjacent to each other. In this case, the columns 4D and 4D adjacent to each other serve as a filter for foreign matters contained in the ink. Further, the diameter of the pillar 4 </ b> D may be larger than the width of the protrusion 6. In this case, the column 4D can be brought into close contact with the protrusion 6.

  Further, like the ink discharge head 103 shown in FIG. 10, the protrusion 6 may not be provided with a column, and the interval L2 between the protrusions 6 and 6 adjacent to each other may be narrower than the width L1 of the flow path 5A. In this case, the protrusions 6 and 6 adjacent to each other serve as a filter for foreign matters contained in the ink.

  Further, the end 2 </ b> A of the ink supply port 2 may be the same as the entrance of the flow path 5 </ b> A of the ink chamber 5 as in the ink discharge head 105 shown in FIG. 12. In this case, the narrowing portion of the flow path 5A and the ink filling property to the ink chamber 5 can be separated and function.

  The ink supply port 2 may be formed by cutting the substrate 11 with a dicing blade (circular saw) and opening it along the longitudinal direction of the substrate 11. In the above-described embodiment, the nozzle layer 20 is formed by applying and drying a resin dissolved in a solvent. However, the nozzle layer 20 may be formed by placing a film-like photocurable resin or a film-like resin having discharge holes formed thereon.

  In the above-described embodiment, the nozzle layer 20, the side wall 19A, the partition wall 19B, and the pillar 4 are configured separately. However, the nozzle layer 20, the side wall 19A, the partition wall 19B, and the pillar 4 may be integrally configured.

  Although the present invention has been described above in connection with the most practical and preferred embodiments at the present time, the present invention is not limited to the embodiments disclosed herein. The invention can be changed as appropriate without departing from the spirit or concept of the invention that can be read from the claims and the entire specification, and an ink discharge head with such a change should also be understood as being included in the technical scope. I must. The present invention can be applied not only to an ink discharge head that discharges ink but also to an apparatus that discharges various liquids. For example, the present invention can be applied to an apparatus that discharges a reagent for DNA analysis.

DESCRIPTION OF SYMBOLS 1 Ink ejection hole 2 Ink supply port 2A End part 2B 1st opening 2C 2nd opening 4 Column 5 Ink chamber 5A Flow path 5B Flow path 6 Protrusion part 10 Substrate layer 11 Substrate 12 Insulating layer 13 Heater 14 Wiring 15 Protective layer 16 Protection Film 17 Insulating layer 18 Adhesion enhancing layer 19A Side wall 19B Partition wall 19C Edge 20 Nozzle layer 21 Water repellent film 22 Resist 27 Sacrificial layer 30 Barrier layer 100, 101, 102, 103, 104, 105 Ink discharge head

Claims (3)

A planar substrate;
A plurality of energy generating elements provided on one surface of the substrate and imparting energy to the liquid for discharging the liquid;
A nozzle layer having a plurality of discharge holes for discharging the liquid, facing one surface of the substrate;
A plurality of flow path walls each defining a liquid chamber including the energy generating element between the one surface and the nozzle layer;
A liquid supply port that communicates a first opening formed at a position away from the energy generating element and a second opening formed on the other surface of the substrate on the one surface;
A liquid flow path for supplying the liquid supplied from the first opening to the liquid chamber;
A liquid ejection device comprising: a projecting portion extending from an end portion of the first opening corresponding to one end portion of the flow path wall to a center side of the first opening;
A column is formed between the protrusion and the nozzle layer,
The liquid ejection apparatus according to claim 1, wherein the column is provided only in the liquid ejection apparatus that ejects a liquid with a relatively low ejection frequency. 2. The liquid ejection according to claim 1 , wherein a width of the liquid flow path is wider than a distance between a pair of adjacent flow path walls in which the liquid flow path is formed and the corresponding protrusions. apparatus. The liquid ejection apparatus according to claim 1 , wherein an interval between the columns adjacent to each other is narrower than a width of the liquid channel .

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