JP5966630B2 - Inkjet head substrate and manufacturing method thereof - Google Patents

Description

  The present invention relates to an ink jet head substrate that ejects ink and a method of manufacturing the same.

  2. Description of the Related Art Conventionally, an inkjet head substrate that discharges ink and a manufacturing method thereof are known. For example, in the method for manufacturing a liquid discharge head described in Patent Document 1, a plurality of ink discharge energy generating elements made of a heating resistor or the like are arranged on a substrate. A resin layer serving as an adhesion layer is formed on the surface of the substrate. Next, a flow path wall is formed on the resin layer. An embedding material is deposited between the channel walls and on the upper surface of the channel wall. The top surface of the deposited embedding material is polished, planarized and cleaned by chemical mechanical polishing (CMP) until the top surface of the channel wall is exposed. A photosensitive resin, a water repellent, a protective material, and the like are laminated on the polished embedding material and the exposed upper surface of the flow path wall to form an ink discharge port. Thereafter, the embedding material is removed.

JP 2007-55240 A

  However, in the conventional method for manufacturing a liquid discharge head, the upper surface of the flow path wall is polished by chemical mechanical polishing (CMP). For this reason, the upper surface of a flow-path wall is planarized like a mirror surface. Therefore, the area where the upper layer of the flow channel wall (the nozzle layer where the ink ejection port is formed) and the flow channel wall come into contact is minimized. Since the contact area is small, the adhesion strength between the upper layer of the flow path wall and the flow path wall is reduced. Every time ink is ejected, a force is applied to the upper layer of the channel wall in the direction of peeling from the channel wall due to the pressure of the ink. However, the adhesion strength between the upper layer of the channel wall and the channel wall is low. If it is small, there is a problem that the upper layer of the flow path wall may be easily peeled off from the flow path wall.

  An object of the present invention is to provide an ink jet head substrate and a method for manufacturing the same, which can make it difficult to peel off an upper layer of a layer forming an ink flow path.

  An inkjet head substrate according to a first aspect of the present invention includes a plurality of nozzles that eject ink, an ink supply port that supplies the ink, and an ink flow path that supplies the ink from the ink supply port to the nozzle. An ink-jet head substrate comprising: a channel-forming layer that is a layer having a wall portion that forms at least a part of the ink channel; and a layer formed on the channel-forming layer. A nozzle layer that forms the nozzle, a first concavo-convex portion that is a concavo-convex portion provided in a portion that contacts the nozzle layer in the flow path forming layer, and a portion that contacts the flow path forming layer in the nozzle layer The first nozzle layer uneven portion is an uneven portion provided on the first nozzle layer, and the first uneven portion and the first nozzle layer uneven portion are along each other. In this case, the flow path forming layer and the nozzle layer are in contact with each other while the first uneven portion and the first nozzle layer uneven portion are along each other. For this reason, a contact area becomes large compared with the case where a flow path formation layer and a nozzle layer contact in a plane. Therefore, the adhesion strength between the flow path forming layer and the nozzle layer is increased. Therefore, it is possible to make it difficult for the nozzle layer to peel from the flow path forming layer.

  The inkjet head substrate may include a second nozzle layer concavo-convex portion that is a concavo-convex portion provided in a portion of the nozzle layer that is in contact with the ink flow path. In this case, the flow resistance to the ink in the ink flow path and the direction in which the ink flows can be controlled by the second nozzle layer uneven portion.

  In the inkjet head substrate, the surface roughness of the portion where the first nozzle layer uneven portion is provided may be larger than the surface roughness of the portion where the second nozzle layer uneven portion is provided. In this case, it is possible to improve the adhesion strength between the flow path forming layer and the nozzle layer due to the first nozzle layer uneven portion while reducing the influence of the second nozzle layer uneven portion on the volume of the ink flow path.

  In the inkjet head substrate, the plurality of nozzles are respectively arranged outside the ink supply port to form a nozzle row, and the second nozzle layer uneven portion extends from the nozzle row toward the ink supply port. It may be formed by a plurality of grooves. In this case, it is possible to reduce the remaining ink flow when ink is ejected from adversely affecting the filling of ink into other nozzles.

  In the inkjet head substrate, the plurality of nozzles are respectively arranged outside the ink supply port to form a nozzle row, and the second nozzle layer concavo-convex portion is in a direction from the nozzle row to the ink supply port. You may be formed of the several groove part extended along the orthogonal direction. In this case, it is difficult for the ink to flow in the direction from the nozzle toward the ink supply port, and the force for pushing out the ink efficiently propagates to the nozzle side. For this reason, for example, even when the viscosity of the ink is high at a low temperature, the ink having a predetermined momentum can be reliably discharged from the nozzle, and the landing error can be reduced and the printing quality can be maintained.

  According to a second aspect of the present invention, there is provided a method for manufacturing an inkjet head substrate, comprising: a plurality of nozzles that eject ink; an ink supply port that supplies the ink; and the ink that is supplied from the ink supply port to the nozzle. And a flow path layer forming step of forming a flow path forming layer, which is a layer having a wall portion that forms at least a part of the ink flow path. And forming a nozzle layer, which is a layer on which the nozzle is formed, on the flow path forming layer formed by the flow path layer forming step, and providing the nozzle layer in the flow path forming layer in contact with the nozzle layer. Forming a first uneven portion, which is an uneven portion, and a first nozzle layer uneven portion, which is an uneven portion provided in a portion of the nozzle layer that is in contact with the flow path forming layer. Eteiru. In the ink jet head substrate manufactured by this manufacturing method, the flow path forming layer and the nozzle layer are in contact with each other with the first uneven portion and the first nozzle layer uneven portion being in line with each other. For this reason, a contact area becomes large compared with the case where a flow path formation layer and a nozzle layer contact in a plane. Therefore, the adhesion strength between the flow path forming layer and the nozzle layer is increased. Therefore, it is possible to make it difficult for the nozzle layer to peel from the flow path forming layer.

  In the manufacturing method, the layer forming step includes a material that fills the ink flow path in a region including the ink flow path formed by the wall portion of the flow path forming layer formed by the flow path layer forming process. An embedding step of disposing an embedding material, a cutting step of cutting the flow path forming layer and the embedding material to form the first uneven portion by cutting in the flow path forming layer, and the flow path forming The nozzle layer is formed on the portion cut by the cutting step of the layer and the embedding material, and the portion in contact with the flow path forming layer in the nozzle layer is formed along the first uneven portion. A nozzle layer forming step for forming the first nozzle layer uneven portion, and further including a removing step for forming the ink flow path by removing the embedding material.

  In the ink jet head substrate manufactured by this manufacturing method, the flow path forming layer and the nozzle layer are in contact with each other with the first uneven portion and the first nozzle layer uneven portion being in line with each other. For this reason, a contact area becomes large compared with the case where a flow path formation layer and a nozzle layer contact in a plane. Therefore, the adhesion strength between the flow path forming layer and the nozzle layer is increased. Therefore, it is possible to make it difficult for the nozzle layer to peel from the flow path forming layer.

  In the manufacturing method, the cutting step includes cutting the flow path forming layer and the embedded material to form the first uneven portion in the flow path forming layer, and forming the second uneven portion by cutting the embedded material. In the nozzle layer forming step, the nozzle layer is formed, the first nozzle layer uneven portion is formed in a portion of the nozzle layer that contacts the flow path forming layer, and the embedding in the nozzle layer is performed. A second nozzle layer concavo-convex portion that is a concavo-convex portion is formed along the second concavo-convex portion at a portion that contacts the material, and the removing step removes the embedding material to form the ink flow path, You may make the said 2nd nozzle layer uneven | corrugated | grooved part the state which contact | connects the said ink flow path. In the ink jet head substrate manufactured by this manufacturing method, the flow resistance to the ink in the ink flow path and the direction in which the ink flows can be controlled by the second nozzle layer uneven portion.

  In the manufacturing method, in the cutting step, the flow path forming layer and the surface roughness of the part where the first uneven part is provided are larger than the surface roughness of the part where the second uneven part is provided. The embedding material may be cut. In this case, the surface roughness of the portion where the first nozzle layer uneven portion corresponding to the first uneven portion formed in the nozzle layer forming step is provided is the second nozzle layer uneven portion corresponding to the second uneven portion. It becomes larger than the surface roughness of the site. For this reason, the ink jet head substrate improves the adhesion strength between the flow path forming layer and the nozzle layer by the first nozzle layer uneven portion while reducing the influence of the second nozzle layer uneven portion on the volume of the ink flow path. be able to.

  The manufacturing method includes a nozzle forming step of forming a nozzle row in which the plurality of nozzles are arranged in the nozzle layer so that the plurality of nozzles are arranged outside the ink supply port, and the cutting step includes: The second concavo-convex portion may be formed by forming a plurality of groove portions extending from the position where the nozzle row is disposed toward the position where the ink supply port is disposed in the embedding material. In this case, the second nozzle layer uneven portion corresponding to the second uneven portion, which is formed in the nozzle layer forming step, is formed by the groove portion extending from the position where the nozzle row is disposed toward the ink supply port. For this reason, the ink jet head substrate can reduce the remaining ink flow when ink is ejected from adversely affecting the filling of ink into other nozzles.

  The manufacturing method includes a nozzle forming step of forming a nozzle row in which the plurality of nozzles are arranged in the nozzle layer so that the plurality of nozzles are arranged outside the ink supply port, and the cutting step includes: Even if the second concavo-convex portion is formed by forming a plurality of groove portions extending in a direction orthogonal to a direction from the position where the nozzle row is disposed toward the position where the ink supply port is disposed, in the embedding material. Good. In this case, the second nozzle layer concavo-convex portion corresponding to the second concavo-convex portion formed in the nozzle layer forming step is perpendicular to the direction from the position where the nozzle row is disposed toward the position where the ink supply port is disposed. Are formed by a plurality of grooves extending in the direction. Ink is less likely to flow in the direction from the nozzle toward the ink supply port, and the force for pushing out the ink efficiently propagates to the nozzle side. For this reason, for example, even when the viscosity of the ink is high at a low temperature, the ink having a predetermined momentum can be reliably discharged from the nozzle, and the landing error can be reduced and the printing quality can be maintained.

According to a third aspect of the present invention, there is provided a method for manufacturing an ink jet head substrate, comprising: a plurality of nozzles that eject ink; an ink supply port that supplies the ink; and the ink that is supplied from the ink supply port to the nozzle. And a flow path layer forming step of forming a flow path forming layer, which is a layer having a wall portion that forms at least a part of the ink flow path. And forming a nozzle layer, which is a layer on which the nozzle is formed, on the flow path forming layer formed by the flow path layer forming step, and providing the nozzle layer in the flow path forming layer in contact with the nozzle layer. Forming a first uneven portion, which is an uneven portion, and a first nozzle layer uneven portion, which is an uneven portion provided in a portion of the nozzle layer that is in contact with the flow path forming layer. For example, the layer forming step includes a concavo-convex part forming step of forming the first nozzle layer uneven portion on the nozzle layer which is formed of a material layer, the first nozzle layer uneven portion by the convex part forming step forms is the nozzle layer disposed on the flow path forming layer was, Ru and a disposing step of forming the flow path forming layer wherein the first concave-convex portion along a first nozzle layer uneven portion. In the ink jet head substrate manufactured by this manufacturing method, the flow path forming layer and the nozzle layer are in contact with each other with the first uneven portion and the first nozzle layer uneven portion being in line with each other. For this reason, a contact area becomes large compared with the case where a flow path formation layer and a nozzle layer contact in a plane. Therefore, the adhesion strength between the flow path forming layer and the nozzle layer is increased. Therefore, it is possible to make it difficult for the nozzle layer to peel from the flow path forming layer.

  In the manufacturing method, the concavo-convex portion forming step forms the first nozzle layer concavo-convex portion and a second nozzle layer concavo-convex portion which is a concavo-convex portion on the nozzle layer, and the arranging step includes the nozzle layer It arrange | positions on a flow-path formation layer, While forming the said 1st uneven part in the said flow-path formation layer, you may arrange | position the said 2nd nozzle layer uneven part of the said nozzle layer in the site | part which contact | connects the said ink flow path. . In the ink jet head substrate manufactured by this manufacturing method, the flow resistance to the ink in the ink flow path and the direction in which the ink flows can be controlled by the second nozzle layer uneven portion.

  In the manufacturing method, in the uneven portion forming step, the surface roughness of the portion where the first nozzle layer uneven portion is provided is larger than the surface roughness of the portion where the second nozzle layer uneven portion is provided. As described above, the first nozzle layer uneven portion and the second nozzle layer uneven portion may be formed. The substrate for an inkjet head manufactured by this manufacturing method reduces the influence of the second nozzle layer uneven portion on the volume of the ink flow path, while the first nozzle layer uneven portion adheres to the flow path forming layer and the nozzle layer. Strength can be improved.

  The manufacturing method includes a nozzle forming step of forming a nozzle row in which the plurality of nozzles are arranged in the nozzle layer so that the plurality of nozzles are arranged outside the ink supply port, and the uneven portion forming step. Even if the second nozzle layer uneven portion is formed by forming, in the nozzle layer, a plurality of groove portions extending from the position where the nozzle row is disposed toward the position where the ink supply port is disposed. Good. The inkjet head substrate manufactured by this manufacturing method can reduce the remaining ink flow when ink is ejected from adversely affecting the filling of ink into other nozzles.

  The manufacturing method includes a nozzle forming step of forming a nozzle row in which the plurality of nozzles are arranged in the nozzle layer so that the plurality of nozzles are arranged outside the ink supply port, and the uneven portion forming step. Forming a plurality of groove portions in the nozzle layer extending in a direction orthogonal to a direction from the position where the nozzle row is disposed toward the position where the ink supply port is disposed, thereby forming the second nozzle layer uneven portion. It may be formed. In this case, it is difficult for the ink to flow in the direction from the nozzle toward the ink supply port, and the force for pushing out the ink efficiently propagates to the nozzle side. For this reason, for example, even when the viscosity of the ink is high at a low temperature, the ink having a predetermined momentum can be reliably discharged from the nozzle, and the landing error can be reduced and the printing quality can be maintained.

  In the manufacturing method, the molecular weight of the material of the flow path forming layer formed by the flow path layer forming process is smaller than the molecular weight of the embedding material arranged by the embedding process, and the cutting process has a different molecular weight. By cutting the flow path forming layer and the embedding material, the surface roughness of the part where the first uneven part is provided is larger than the surface roughness of the part where the second uneven part is provided. The path forming layer and the embedding material may be cut. When the molecular weight is small, when the material is cut, it tends to be cut more roughly. For this reason, even when the flow path forming layer and the embedding material are cut under the same conditions (such as force applied) with the cutting blade, the flow path forming layer is rougher than the embedding material. Therefore, the surface roughness of the first uneven portion of the flow path forming layer is larger than the surface roughness of the second uneven portion. Therefore, even if the flow path forming layer and the embedding material are not cut under different conditions, the surface roughness of the first nozzle layer uneven portion along the first uneven portion is changed to the second nozzle layer uneven portion along the second uneven portion. The surface roughness can be made larger. Since it is not necessary to cut the flow path forming layer and the embedding material under different conditions, the cutting process can be performed efficiently.

  In the manufacturing method, the Young's modulus of the material of the flow path forming layer formed by the flow path layer forming step is smaller than the Young's modulus of the embedding material disposed by the embedding step, and the cutting step includes a Young's modulus. By cutting the flow path forming layer and the embedding material different from each other, the surface roughness of the portion where the first uneven portion is provided is larger than the surface roughness of the portion where the second uneven portion is provided. The flow path forming layer and the embedding material may be cut. In this case, since the Young's modulus of the material of the flow path forming layer is smaller than the Young's modulus of the embedding material, the flow path forming layer is more likely to be distorted than the embedding material and has a lower rigidity. For this reason, even if the flow path forming layer and the embedding material are cut under the same conditions (such as force applied) with the blade, the flow path forming layer is more easily scraped than the embedding material. Therefore, the surface roughness of the first uneven portion of the flow path forming layer is larger than the surface roughness of the second uneven portion. Therefore, even if the flow path forming layer and the embedding material are not cut under different conditions, the surface roughness of the first nozzle layer uneven portion along the first uneven portion is changed to the second nozzle layer uneven portion along the second uneven portion. The surface roughness can be made larger. Since it is not necessary to cut the flow path forming layer and the embedding material under different conditions, the cutting process can be performed efficiently.

It is a top view of the board | substrate 1 for inkjet heads. It is an AA arrow direction partial fragmentary sectional view in FIG. 3 is a flowchart showing manufacturing steps of the inkjet head substrate 1. It is sectional drawing of the state in which the heater part 15 and the protective layer 28 were formed. It is sectional drawing of the state in which the flow-path formation layer 29 was formed. It is sectional drawing of the state by which the embedding material 39 is arrange | positioned. It is sectional drawing in the state in which the 1st uneven part 291 and the 2nd uneven part 392 were formed. It is a top view which shows the state by which the some ink discharge unit 5 arrange | positioned on the silicon wafer 60 is cut in the front-back direction at a cutting process (S5). It is sectional drawing of the state in which the nozzle layer 30 was formed. It is sectional drawing of the ink discharge unit 5 of the state which discharged the ink. It is a top view which shows the state by which the some ink discharge unit 5 arrange | positioned on the silicon wafer 60 is cut in the left-right direction by a cutting process (S5). It is a flowchart which shows the manufacturing process of the board | substrate 1 for inkjet heads which concerns on 2nd embodiment. FIG. 4 is a cross-sectional view showing how a layered material 31 is formed using a mold 33. 2 is a front view of a bar coater 40. FIG. 4 is a side view showing a state in which a layered material 31 is formed using a bar coater 40. FIG.

  Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings. In the following description, the upper side, the lower side, the right side, the left side, the front side of the page, and the back side of the page in FIG. 1 will be described as the rear side, front side, right side, left side, upper side, and lower side of the inkjet head substrate 1. .

  With reference to FIG.1 and FIG.2, the board | substrate 1 for inkjet heads which concerns on 1st embodiment is demonstrated. As shown in FIG. 1, the inkjet head substrate 1 includes an ink discharge unit 5 and a flexible printed circuit board 20. A rectangular ink supply port 10 that is long in the front-rear direction is provided at a slightly right side of the central portion in plan view of the ink discharge unit 5. On the left side of the ink supply port 10, a nozzle row 3 that is a row of a plurality of nozzles 2 arranged in the front-rear direction is provided. The ink supply port 10 is an opening for supplying ink to each nozzle 2 of the nozzle row 3. The ink supplied from the ink supply port 10 is ejected from the nozzle 2 to the outside.

  A wall portion 295 is provided around the ink supply port 10 and the nozzle 2. The wall portion 295 is formed by a flow path forming layer 29 (see FIG. 2) described later. The wall portion 295 forms a part (side wall) of the ink flow path 11. The ink flow path 11 is a flow path for supplying ink from the ink supply port 10 to the nozzle 2. The ink flow path 11 is provided above the ink supply port 10 and around the ink supply port 10 in plan view. The ink flow path 11 includes an ink chamber 4 and a passage 6. The ink chamber 4 is a space formed by a wall portion 295 surrounding the front side, the rear side, and the left side of each nozzle 2. The passage 6 is a portion that extends slightly to the right from the ink chamber 4 toward the ink supply port 10. Each nozzle 2 is separated by a wall portion 295 that forms the ink chamber 4 and the passage 6.

  The flexible printed circuit board 20 is connected to the left part of the ink discharge unit 5. On the flexible printed circuit board 20, two power electrode pads 21 and the same number of channel electrode pads 23 as the number of nozzles 2 are arranged in the front-rear direction. The two power supply electrode pads 21 are located outside the plurality of channel electrode pads 23. The power supply electrode pad 21 is connected to a power supply Vcc (not shown). Further, a common wiring 22 is connected between the two power supply electrode pads 21. The common wiring 22 extends rightward from the power supply electrode pad 21 on the rear end side (upper side in FIG. 1) and bends forward. The common wiring 22 extends straight forward along the plurality of nozzles 2, bends to the left, and is connected to the power supply electrode pad 21 on the front end side. Each of the plurality of channel electrode pads 23 is connected to each of N channels (Ch1 to ChN, where N is the number of nozzles 2) (not shown). Each of Ch1 to ChN is connected to GND (not shown), and ON (connected) and OFF (not connected) are switched by a switch.

  As shown in FIG. 2, the ink ejection unit 5 has a laminated structure in which a plurality of layers are laminated. A heater portion 15 is provided immediately below each of the plurality of nozzles 2. The left end of each heater section 15 is connected to the first conduction path 16 and the right end is connected to the second conduction path 17.

  As shown in FIG. 1, the plurality of first conduction paths 16 are connected to a plurality of channel electrode pads 23, respectively. The plurality of second conduction paths 17 are all connected to the common wiring 22. Each of the first conduction paths 16 may be provided with an adjustment resistor portion (not shown) for adjusting the amount of heat generated in the heater portion 15.

The principle of ejecting ink from the nozzle 2 will be described. For example, when the Nth channel is turned on by the switch, the current supplied by the power source flows to the Nth conduction paths 16 and 17 through the common wiring 22 (see FIG. 1). As shown in FIG. 2, the heater portion 15 is a portion where the first conduction path 16 and the second conduction path 17 are separated from each other. A resistor 26 is in contact with the bottoms of the first conduction path 16 and the second conduction path 17. In the portion where the conduction paths 16 and 17 are formed, the current flows through the conduction paths 16 and 17, so that no current flows through the resistor 26 and no heat is generated. On the other hand, since the conduction paths 16, 17 in the heater 15 is interrupted, the current generates heat the resistor 26 flows. That is, a portion of the resistor 26 between the first conduction path 16 and the second conduction path 17 serves as a heating resistor portion 18 that generates heat when a current flows. When heat is generated in the heat generating resistor 18, the ink in the ink chamber 4 is vaporized and the volume increases rapidly. As a result, the ink in the Nth ink chamber 4 is ejected from the nozzle 2.

  With reference to FIG. 2, each layer with which the ink discharge unit 5 is provided is demonstrated. The ink discharge unit 5 includes a substrate 25, a resistor 26, a wiring conductor 27, a protective layer 28, a flow path forming layer 29, and a nozzle layer 30 in order from the bottom. The substrate 25 is a silicon (Si) substrate, and supports the entire inkjet head substrate 1. An ink supply port 10 is formed in the substrate 25. The ink ejected from the plurality of nozzles 2 is supplied through the ink supply port 10. The resistor 26 is a layer formed of a substance that generates heat when a current flows. In the present embodiment, tantalum aluminum (TaAl) is used as a material for forming the resistor 26. The wiring conductor 27 may be formed of a conductive material. By removing a part of the wiring conductor 27, the first conduction path 16 and the second conduction path 17 are formed. In the present embodiment, the wiring conductor 27 is formed of an Al—Cu alloy.

  The protective layer 28 covers the wiring conductor 27 and the resistor 26 and protects them from ink. In the present embodiment, the protective layer 28 is formed of silicon nitride (SiNx). The flow path forming layer 29 is a layer having a wall portion 295 that forms at least a part of the ink flow path 11. The ink flow path 11 is an ink flow path for supplying ink from the ink supply port 10 to the nozzle 2. The flow path forming layer 29 forms the ink flow path 11 by separating the protective layer 28 and the nozzle layer 30. The nozzle layer 30 is a layer formed on the flow path forming layer 29. The nozzle layer 30 is formed with a nozzle 2 that passes through the ink flow path 11. The nozzle 2 is located above the heater unit 15. In the present embodiment, the flow path forming layer 29 and the nozzle layer 30 are formed of an epoxy resin.

  A first concavo-convex portion 291 that is an concavo-convex portion is provided in a portion of the flow passage forming layer 29 that contacts the nozzle layer 30 (an upper surface of the flow passage forming layer 29). A first nozzle layer uneven portion 301 that is an uneven portion is provided in a portion (the lower surface of the nozzle layer 30) in contact with the flow path forming layer 29 in the nozzle layer 30. The first uneven portion 291 and the first nozzle layer uneven portion 301 are along each other. For this reason, the flow path forming layer 29 and the nozzle layer 30 are in close contact with each other by the first uneven portion 291 and the first nozzle layer uneven portion 301. Further, the first uneven portion 291 and the first nozzle layer uneven portion 301 are in a direction orthogonal to the direction from the nozzle row 3 toward the ink supply port 10 (in this embodiment, the front-rear direction, hereinafter may be referred to as “orthogonal direction”). Are formed by a plurality of grooves extending in the direction.

  A second nozzle layer concavo-convex portion 302 is provided in a portion of the nozzle layer 30 that contacts the ink flow path 11 (the lower surface of the nozzle layer 30). The 2nd nozzle layer uneven | corrugated | grooved part 302 is formed of the groove part extended in an orthogonal direction (front-back direction).

  A manufacturing process of the ink discharge unit 5 (see FIG. 1) of the inkjet head substrate 1 will be described with reference to FIGS. A plurality of ink discharge units 5 of the inkjet head substrate 1 are manufactured from one silicon wafer 60 (see FIG. 8). Further, the illustration of the thickness of each layer, the size of the concavo-convex portion, and the like is different from the actual thickness for easy understanding of the explanation. As shown in FIG. 3, when the manufacturing process is started, a heater portion forming process (S1) is performed. As shown in FIG. 4, in the heater portion forming step (S 1), first, a tantalum aluminum film is formed on the entire upper surface of the substrate 25. A photosensitive resist is applied to the tantalum aluminum film, and the same pattern as the pattern of the wiring conductor 27 (see FIG. 2) (in a plan view) is subjected to mask exposure. Next, the unexposed portion is removed by etching, and a plurality of resistors 26 having a plan view shape are formed. A plurality of wiring conductors 27 in a plan view are formed on the upper surface of the resistor 26 so as to match the shape of the resistor 26. As a method for forming the wiring conductor 27, for example, film formation / mask exposure / etching may be used as in the method of forming the resistor 26.

  Next, a portion of the wiring conductor 27 located in the heater portion 15 is removed by a physical or chemical method such as laser trimming, sand blasting, or etching. As a result, a portion of the resistor 26 located in the heater portion 15 becomes a heating resistor portion 18 (energy generating element) that generates heat when a current flows. The wiring conductor 27 remaining without being removed becomes the first conduction path 16 and the second conduction path 17. Although not shown, a part of the wiring conductor 27 that is separated from the heater 15 is also removed. As a result, an adjustment resistor portion is formed. By adjusting the resistance value of the adjustment resistor portion (that is, the length of the portion from which the wiring conductor 27 is removed), the amount of heat generated in the heater portion 15 can be adjusted. Next, a protective layer 28 is formed by sputtering or CVD (Chemical Vapor Deposition) so as to cover all of the resistor 26, the first conduction path 16, and the second conduction path 17, and the heater portion formation step (S1) is completed. To do.

Although not shown, a heat storage layer for preventing heat conduction from the resistor 26 to the substrate 25 may be provided between the substrate 25 and the resistor 26. For example, a layer of silicon dioxide (SiO ₂ ) formed by thermally oxidizing the surface of the substrate 25 may be used as the heat storage layer. Further, a cavitation film (not shown) made of tantalum (Ta) may be formed on the upper surface of the protective layer 28. The anti-cavitation film prevents the protective layer 28 from being eroded by an impact force applied many times near the center of the heater portion 15 due to cavitation, and improves the durability of the heater portion 15. Cavitation is a phenomenon in which bubbles 80 are generated and disappeared in a short time due to a pressure difference between liquids, and a large impact force is generated at the time of disappearance.

  Next, a step portion forming step (S2) is performed. As shown in FIG. 5, in the step portion forming step (S2), the protective layer 28 and a part of the upper portion of the substrate 25 are removed by etching or the like, thereby forming a step portion 35 having a rectangular shape in plan view. The range where the step portion 35 is formed is a range wider than the portion where the ink supply port 10 (see FIG. 2) is formed, and the heater portion 15, the first conduction path 16, and the second conduction path 17. The range does not overlap.

  Next, a flow path forming layer forming step (S3) is performed. As shown in FIG. 5, in the flow path forming layer forming step (S3), an epoxy resin layer is formed on the upper surface of the protective layer 28 by spin coating or film lamination. Thus, an epoxy resin layer having a predetermined thickness (for example, 40 μm) is formed. Then, a wall portion 295 for forming the ink flow path 11 is formed by pattern exposure, development, and baking, and the epoxy resin layer becomes the flow path forming layer 29.

Next, an embedding step (S4) is performed. As shown in FIG. 6, in the embedding step (S <b> 4), the material for filling the ink flow path in the region including the ink flow path 11 (see FIG. 5) formed by the wall portion 295 of the flow path forming layer 29 is used. An embedding material 39 is disposed. The embedding material 39 is formed so as to cover all of the protective layer 28 and the flow path forming layer 29. In the present embodiment, the embedding material 39 and the flow path forming layer 29 have different Young's modulus materials. Specifically, for example, the flow path forming layer 29 uses an epoxy resin having a Young's modulus of about 4000 N / mm ² . As the embedding material 39, a novolac resin having a Young's modulus of about 7000 N / mm ² is used. The Young's modulus is an index representing elasticity, and the greater the Young's modulus, the less the distortion is generated and the higher the rigidity.

  Next, a cutting process (S5) is performed. In the cutting step (S5), the flow path forming layer 29 and the embedding material 39 are cut. At this time, cutting is performed until at least the upper surface of the flow path forming layer 29 is cut. As a result, a first uneven portion 291 is formed on the upper surface of the flow path forming layer 29 by cutting. In addition, a second uneven portion 392 is formed on the upper surface of the embedding material 39 by cutting.

  In the cutting step (S5), for example, cutting is performed using a cutting machine having a blade 70 that rotates with a diameter larger than that of the silicon wafer 60 (see FIG. 8). At this time, the blade 70 of the cutting machine cuts the surfaces of the flow path forming layer 29 and the embedding material 39 in the orthogonal direction (front-rear direction, see arrow 90 in FIG. 8). For this reason, a plurality of groove portions are formed in the front-rear direction, and the first uneven portion 291 and the second uneven portion 392 are formed. The depth of the groove that forms the first uneven portion 291 is, for example, 0.8 μm, and the depth of the groove that forms the second uneven portion 392 is, for example, 0.4 μm.

  Here, since the channel forming layer 29 has a Young's modulus smaller than that of the embedding material 39, when cutting with the blade 70 under the same conditions as the applied force, the channel forming layer 29 is more preferable than the embedding material 39. It becomes easy to cut. Therefore, the surface roughness Ra of the first uneven portion 291 of the flow path forming layer 29 is larger than the surface roughness Ra of the second uneven portion 392 of the embedding material 39. That is, by cutting the flow path forming layer 29 and the embedding material 39 having different Young's moduli, the surface roughness Ra of the portion where the first uneven portion 291 in the flow path forming layer 29 is formed is the first in the embedding material 39. It becomes larger than the surface roughness Ra of the part where the two uneven portions 392 are formed. The surface roughness Ra is an index representing the surface roughness defined by Japanese Industrial Standards (JIS, Japanese Industrial Standards), and can be measured by, for example, a surface roughness measuring instrument.

  Next, a nozzle layer forming step (S6) is performed. As shown in FIG. 9, in the nozzle layer forming step (S6), the nozzle layer 30 is formed on the portion (upper surface) cut by the cutting step (S5) of the flow path forming layer 29 and the embedding material 39. . In the nozzle layer forming step (S6), the laminate tape formed of epoxy resin is bonded to the upper side of the flow path forming layer 29 and the embedding material 39 by thermocompression bonding, so that the nozzle layer 30 formed of epoxy resin. Is formed. A first uneven portion 291 is formed on the upper surface of the flow path forming layer 29, and a second uneven portion 392 is formed on the upper surface of the embedding material 39. For this reason, the first nozzle layer uneven portion 301 along the first uneven portion 291 is formed at a portion in contact with the flow path forming layer 29 on the lower surface of the nozzle layer 30. Further, a second nozzle layer uneven portion 302 along the second uneven portion 392 is formed at a portion that contacts the embedding material 39 on the lower surface of the nozzle layer 30.

  Next, a nozzle forming step (S7) is performed. In the nozzle forming step (S7), a plurality of nozzles 2 that pass through the nozzle layer 30 are formed from the upper surface of the nozzle layer 30 to the portion where the ink flow path 11 is formed (the portion where the embedding material 39 is located). At this time, a nozzle row 3 in which a plurality of nozzles 2 are arranged outside the ink supply port 10 is formed. As shown in FIG. 2, each of the plurality of nozzles 2 is located above the heater unit 15. In the present embodiment, the plurality of nozzles 2 are formed by photolithography, but the method of forming the nozzles 2 is not limited to this. For example, a film in which the nozzle 2 is formed in advance may be used as the nozzle layer 30.

  Next, an ink supply port forming step (S8) is performed. As shown in FIG. 2, in the ink supply port forming step (S8), after the surface of the nozzle layer 30 is protected, holes are formed in the substrate 25 by etching or the like, and the ink supply port 10 is formed. Then, the protection process of the surface of the nozzle layer 30 is cancelled | released.

  Next, a removal step (S9) is performed. As shown in FIG. 2, in the removing step (S9), the embedding material 39 is removed and the ink flow path 11 is formed. In the removing step (S9), the embedding material 39 is removed by ultrasonic cleaning. As a result, the second nozzle layer uneven portion 302 comes into contact with the ink flow path 11. The ink discharge unit 5 (see FIG. 1) is manufactured through the above steps. By using the manufactured ink discharge unit 5, a completed body (see FIG. 1) of the inkjet head substrate 1 can be created.

  In the inkjet head substrate 1 of the present embodiment, the first uneven portion 291 is formed in the flow path forming layer 29, and the first nozzle layer uneven portion 301 along the first uneven portion 291 is formed in the nozzle layer 30. Since the first uneven portion 291 and the first nozzle layer uneven portion 301 are provided, the flow path forming layer 29 and the nozzle layer 30 are compared to the case where the flow path forming layer 29 and the nozzle layer 30 are in contact with each other in a plane. Increases the contact area. For this reason, the adhesion strength between the flow path forming layer 29 and the nozzle layer 30 is increased. Therefore, the nozzle layer 30 can be made difficult to peel off from the flow path forming layer 29.

  As shown in FIG. 10, when ink is ejected from the nozzle 2, the heat generating resistor 18 generates heat, the ink is vaporized, and the ink bullet 81 is pushed out of the nozzle 2 by the bubbles 80. At this time, the force for pushing out the ink from the nozzle 2 may be transmitted to the ink remaining in the ink flow path 11. In this case, since the passage 6 as the ink flow path 11 extends from the nozzle 2 to the ink supply port 10, the ink tends to flow in the right direction indicated by the arrow 95 from the nozzle 2 toward the ink supply port 10. However, since the grooves that form the second nozzle layer uneven portion 302 are provided in the orthogonal direction (front-rear direction), the flow resistance between the ink that flows to the right side and the second nozzle layer uneven portion 302 is low. growing.

  In general, the velocity of the fluid is zero at the interface of the flowing wall (viscous liquid) with a stationary wall in contact. The greater the viscosity of the liquid, the worse the liquid flow near the wall, and the more so-called velocity boundary layer develops. In FIG. 10, a velocity boundary layer 97 is a velocity boundary layer generated by friction between the second nozzle layer uneven portion 302, ink, and ink. The velocity boundary layer 98 is a velocity boundary layer generated by the friction between the upper surface of the protective layer 28, ink, and ink. Further, due to the influence of the second nozzle layer uneven portion 302, a stagnant ink vortex indicated by an arrow 96 is generated in the ink near the second nozzle layer uneven portion 302. Since the ink in the region where the vortex is generated hardly flows in the right direction, the speed of the ink in the right direction becomes close to zero. For this reason, the velocity boundary layer 97 further develops. In particular, when the second nozzle layer uneven portion 302 is formed by a groove extending in the orthogonal direction as in the present embodiment, vortices are likely to occur, and the velocity boundary layer 97 is likely to develop greatly.

  When the velocity boundary layers 97 and 98 are generated, a region where ink flows substantially becomes narrow. In particular, since the velocity boundary layer 97 is larger than when the second nozzle layer uneven portion 302 is formed flat, a region where ink flows substantially becomes further narrow, and the flow resistance increases. Since the flow resistance increases, it becomes difficult for ink to flow in the right direction. Therefore, the force for pushing out the ink is not easily transmitted in the right direction, but efficiently propagates to the nozzle 2 side. For this reason, for example, even when the viscosity of the ink is large in a state where the ink is at a low temperature, the ink having a predetermined momentum can be reliably discharged from the nozzle 2. Therefore, the landing position error (landing error) when the ejected ink bullets 81 land on the print medium can be reduced, and the print quality can be kept good.

  Further, when ink is ejected from the nozzle 2, the heat generating resistor portion 18 is heated to generate bubbles 80. Since the second nozzle layer uneven portion 302 is provided, the ink pushing force is efficiently propagated to the nozzle 2 side. Therefore, the bubbles 80 are smaller than when the second nozzle layer uneven portion 302 is not provided. However, the ink having a predetermined momentum can be ejected from the nozzle 2. Since the bubble 80 may be small, it is possible to reduce the electric power for generating the bubble 80 by generating heat in the heating resistor portion 18. Therefore, power can be saved as compared with the case where the second nozzle layer uneven portion 302 is not provided.

  For example, when the temperature of the ink is high and the viscosity of the ink is low, the speed of the ink bullet 81 ejected from the nozzle increases, and the landing error may increase. In addition, due to the low viscosity of the ink, droplets may be generated when the ink is ejected, and the droplets may adhere to the print medium and deteriorate print quality. However, when the viscosity of the ink is small, the velocity boundary layers 97 and 98 are small (thin). For this reason, the region where ink flows substantially effectively expands, and the flow resistance decreases. Since the flow resistance is reduced, the ink can easily flow in the right direction. Therefore, compared with the case where the flow resistance is large, the force for pushing out ink is easily transmitted in the right direction, and the force transmitted to the nozzle 2 side is reduced. For this reason, even when the temperature of the ink is high and the viscosity of the ink is small, it is possible to prevent the speed of the ink bullet 81 from becoming too large, and it is possible to suppress the generation of splashes and maintain good print quality.

  Further, the larger the surface roughness Ra of the first nozzle layer uneven portion 301 and the first uneven portion 291 is, the larger the contact area between the flow path forming layer 29 and the nozzle layer 30 is. Can be made difficult to peel off. On the other hand, the surface roughness Ra of the second nozzle layer uneven portion 302 affects the volume of the ink flow path 11 (ink chamber 4). Specifically, for example, the volume of the ink flow path 11 (ink chamber 4) is too large for the surface roughness Ra of the second nozzle layer uneven portion 302 with respect to the volume at the time of design not considering the surface roughness Ra. In this case, the deviation from the volume at the time of design becomes large. Therefore, when the surface roughness Ra is large, the amount of ink ejected from the nozzle 2 assumed at the time of design and the ink speed may be affected. That is, the surface roughness Ra of the first nozzle layer uneven portion 301 is preferably increased in order to increase the adhesion strength between the flow path forming layer 29 and the nozzle layer 30, but the surface roughness of the second nozzle layer uneven portion 302. It is desirable that Ra is not too large. In the present embodiment, the surface roughness Ra of the first nozzle layer uneven portion 301 is formed to be greater than the surface roughness Ra of the second nozzle layer uneven portion 302. For this reason, while the influence which the 2nd nozzle layer uneven | corrugated | grooved part 302 has on the volume of the ink flow path 11 (ink chamber 4) is reduced, the flow path forming layer 29 and the nozzle layer 30 are closely contacted by the 1st nozzle layer uneven | corrugated | grooved part 301. Strength can be improved. The range that does not affect the volume of the ink chamber 4 is, for example, a range in which the depth of the groove (the height of the unevenness) is 0.03 times or less the thickness of the flow path forming layer 29 after cutting.

  In addition, by simultaneously cutting the flow path forming layer 29 and the embedding material 39 having different Young's moduli, the surface roughness Ra of the portion where the first uneven portion 291 is formed in the flow path forming layer 29 is reduced in the embedding material 39. It becomes larger than the surface roughness Ra of the part where the second uneven portion 392 is formed. Therefore, the surface roughness Ra of the first nozzle layer uneven portion 301 along the first uneven portion 291 is adjusted along the second uneven portion 392 without cutting the flow path forming layer 29 and the embedding material 39 under different conditions. The surface roughness Ra of the second nozzle layer uneven portion 302 can be made larger. Since it is not necessary to cut the flow path forming layer 29 and the embedding material 39 under different conditions, the cutting process can be performed efficiently.

  In the above embodiment, the flow path forming layer forming step (S3) corresponds to the “flow path layer forming step” of the present invention. The flow path forming layer forming step (S3), the embedding step (S4), the cutting step (S5), and the nozzle layer forming step (S6) correspond to the “layer forming step” of the present invention.

  In addition, this invention is not limited to said embodiment, A various change is possible. For example, the surface roughness Ra of the first nozzle layer concavo-convex portion 301 is formed to be larger than the surface roughness Ra of the second nozzle layer concavo-convex portion 302, but is not limited thereto. For example, the surface roughness Ra of the first nozzle layer uneven portion 301 and the surface roughness Ra of the second nozzle layer uneven portion 302 may be the same. Further, the surface roughness Ra of the first nozzle layer uneven portion 301 may be smaller than the surface roughness Ra of the second nozzle layer uneven portion 302.

  In addition, by cutting the flow path forming layer 29 and the embedding material 39 having different Young's moduli, the surface roughness Ra of the portion where the first uneven portion 291 in the flow path forming layer 29 is formed becomes the first in the embedding material 39. Although the cutting is performed so as to be larger than the surface roughness Ra of the portion where the two uneven portions 392 are formed, the present invention is not limited to this. For example, the first uneven portion 291 in the flow path forming layer 29 is formed by increasing the force pressing the blade 70 against the flow path forming layer 29 and increasing the force pressing the blade 70 against the embedding material 39 during cutting. Cutting may be performed so that the surface roughness Ra of the part is larger than the surface roughness Ra of the part of the embedding material 39 where the second uneven portion 392 is formed.

  Further, for example, by cutting the flow path forming layer 29 and the embedding material 39 having different molecular weights, the surface roughness Ra of the site where the first uneven portion 291 is formed in the flow path forming layer 29 is You may cut so that it may become larger than the surface roughness Ra of the site | part in which the 2nd uneven | corrugated | grooved part 392 is formed. In this case, the molecular weight of the material of the flow path forming layer 29 is made smaller than the molecular weight of the embedding material 39. Generally, when the molecular weight is small, there is a tendency that the material is cut more roughly when the material is cut. For this reason, even if the flow path forming layer 29 and the embedding material 39 are cut under the same conditions (such as force applied) by the cutting blade 70, the flow path forming layer 29 is rougher than the embedding material 39. Therefore, the surface roughness of the first uneven portion 291 of the flow path forming layer 29 is larger than the surface roughness of the second uneven portion 392 of the embedding material 39. Therefore, even if the flow path forming layer 29 and the embedding material 39 are not cut under different conditions, the surface roughness of the first nozzle layer uneven portion 301 along the first uneven portion 291 is reduced to the second uneven portion 392. The surface roughness of the two-nozzle layer uneven portion 302 can be made larger. In this case, the flow path forming layer 29 and the embedding material 39 do not have to be cut under different conditions, so that the cutting process can be performed efficiently.

  Further, the plurality of groove portions forming the first nozzle layer uneven portion 301 and the plurality of groove portions forming the second nozzle layer uneven portion 302 extend in the orthogonal direction (front-rear direction), but are not limited thereto. . For example, a plurality of groove portions forming the first nozzle layer uneven portion 301 and a plurality of groove portions forming the second nozzle layer uneven portion 302 may extend in the direction from the nozzle row 3 toward the ink supply port 10. That is, a plurality of grooves forming the first nozzle layer uneven portion 301 and a plurality of grooves forming the second nozzle layer uneven portion 302 may extend in the left-right direction. As described above, when ink is ejected from the nozzle 2, the force for pushing the ink from the nozzle 2 may be transmitted to the ink remaining in the ink flow path 11. Even in this case, since the plurality of groove portions forming the second nozzle layer uneven portion 302 extend in the left-right direction, the ink is guided to the groove portions, and the ink is directed rightward from the nozzle 2 toward the ink supply port 10 (arrow 93 in FIG. 1). Direction). For this reason, the possibility that the ink remaining in the ink flow path will flow toward the other nozzle 2 (the possibility of flowing in the direction of the arrow 94 in FIG. 1) is reduced. Therefore, it can be reduced that the remaining ink flow when ink is ejected adversely affects the filling of the ink into the other nozzles 2 (filling of the ink into the ink chamber 4 after the ink is ejected) or the like.

  Further, after ink is ejected from the nozzle 2, the ink is refilled in the ink chamber 4. At this time, since the plurality of grooves forming the second nozzle layer uneven portion 302 extend in the left-right direction, the ink is guided to the grooves, and the ink is directed leftward from the ink supply port 10 toward the nozzle 2 (opposite of the arrow 93 in FIG. 1). Direction). For this reason, the possibility of attracting ink to be filled in other nozzles 2 (the possibility of ink flowing in the direction opposite to the arrow 94 in FIG. 1) is reduced. Therefore, it is possible to prevent the flow of ink refilled into the ink chamber 4 after ejecting ink from adversely affecting the filling of the ink into the other nozzles 2. As described above, by providing the second nozzle layer uneven portion 302, it is possible to control the flow resistance with respect to the ink in the ink flow path 11 and the direction in which the ink flows.

  In addition, when the some groove part which forms the 1st nozzle layer uneven | corrugated | grooved part 301 and the some groove part which forms the 2nd nozzle layer uneven | corrugated | grooved part 302 are formed so that it may extend in the left-right direction, as shown to the arrow 91 of FIG. Further, the surfaces of the flow path forming layer 29 and the embedding material 39 are cut in the left-right direction in the cutting step (S5). As a result, a first uneven portion 291 and a second uneven portion 392 formed by a plurality of grooves extending in the left-right direction are formed in the flow path forming layer 29, and the first nozzle layer uneven portion is formed by the nozzle layer forming step (S6). A plurality of grooves that form 301 and the second nozzle layer uneven portion 302 are formed to extend in the left-right direction.

  Moreover, although the 1st nozzle layer uneven | corrugated | grooved part 301 and the 2nd nozzle layer uneven | corrugated | grooved part 302 were each formed by the groove part, a shape is not limited. The shape of the first nozzle layer uneven portion 301 and the second nozzle layer uneven portion 302 is not particularly limited as long as the uneven portion is formed. For example, the first nozzle layer uneven portion 301 and the second nozzle layer uneven portion 302 may be formed by providing a plurality of cylindrical portions protruding downward in a columnar shape on the lower surface of the nozzle layer 30. Even in this case, the flow resistance to the ink by the second nozzle layer uneven portion 302 is increased. Moreover, the adhesion strength between the flow path forming layer 29 and the nozzle layer 30 is increased by arranging the first nozzle layer uneven portion 301 and the first uneven portion.

  Moreover, although the 2nd nozzle layer uneven | corrugated | grooved part 302 was provided, it is not limited to this. For example, the 2nd nozzle layer uneven | corrugated | grooved part 302 is not provided, and you may form in a plane. In FIG. 7, the blade 70 extends toward the lower left, but the shape of the blade 70 is not limited. For example, the blade 70 may extend to the lower right or may extend downward.

  In FIG. 2, the first concavo-convex portion 291 and the first nozzle layer concavo-convex portion 301 are in close contact with each other without a gap, but a gap may partially exist. Even in this case, since the contact area with each other is larger than the adhesion interface formed by polishing, the same effect can be obtained. Further, when a gap is formed in a portion where the force to be peeled off from the nozzle layer 30 and the flow path forming layer 29 is not so much (for example, a portion away from the nozzle row 3), stress that causes peeling of both layers is originally generated. It may not be a problem because it does not work that much. In this way, the distribution of the gaps may be changed according to the ease of peeling.

  Moreover, the manufacturing method of the ink discharge unit 5 of the board | substrate 1 for inkjet heads is not limited to 1st embodiment. In the following description, a second embodiment that is a modification of the manufacturing method will be described. In the second embodiment, the nozzle layer 30 is formed using the layered material 31 (see FIG. 13) in which the first nozzle layer uneven portion 301 and the second nozzle layer uneven portion 302 are formed in advance. In the following description, the same configurations and steps as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof is omitted.

  As shown in FIG. 12, in the manufacturing process according to the second embodiment, first, an uneven portion forming step (S11) is performed. In the uneven portion forming step (S <b> 11), the first nozzle layer uneven portion 301 and the second nozzle layer uneven portion 302 are formed in the layered material 31. As shown in FIG. 13, in the concavo-convex portion forming step (S <b> 11), a layer material 31 is formed using a mold 33 for forming the first nozzle layer concavo-convex portion 301 and the second nozzle layer concavo-convex portion 302. . On the upper surface of the mold 33, a first mold uneven portion 331 and a second mold uneven portion 332, which are uneven portions, are provided. The first type uneven portion 331 is an uneven portion for forming the first nozzle layer uneven portion 301 that contacts the flow path forming layer 29. The second mold uneven portion 332 is an uneven portion for forming the second nozzle layer uneven portion 302 that contacts the ink flow path 11. The 1st type uneven | corrugated | grooved part 331 and the 2nd type | mold uneven | corrugated | grooved part 332 are formed of the groove part extended in the front-back direction. In the mold 33, the surface roughness Ra of the portion where the first mold uneven portion 331 is provided is larger than the surface roughness Ra of the portion where the second mold uneven portion 332 is provided. Further, a wall portion (not shown) is erected around the upper surface of the mold 33, so that a solution for forming the nozzle layer 30 can be stored on the upper surface of the mold 33.

  As shown in FIG. 13, in the concavo-convex portion forming step (S <b> 11), a solution (for example, a solution containing an epoxy resin) for forming the layered material 31 is accumulated on the upper surface of the mold 33. Then, it is cured by drying or heating to produce a film-like layered material 31 (for example, an epoxy layer). This layered material 31 is the nozzle layer 30. In the layered material 31, a first nozzle layer uneven portion 301 is formed along the first type uneven portion 331, and a second nozzle layer uneven portion 302 is formed along the second type uneven portion 332.

  Next, similarly to the first embodiment, a heater portion forming step (S1), a step portion forming step (S2), and a flow path forming layer forming step (S3) are performed. As a result, as shown in FIG. 5, the flow path forming layer 29 is formed.

  Next, an arrangement step (S12) is performed. As shown in FIG. 2, in the disposing step (S12), the layered material 31 (nozzle layer 30) prepared in advance in the concavo-convex portion forming step (S11) is disposed on the flow path forming layer 29, for example, by thermocompression bonding. Close contact. At this time, the first nozzle layer uneven portion 301 is disposed on the flow path forming layer 29, and the second nozzle layer uneven portion 302 is disposed on the ink flow path 11. Further, the layered material 31 is pressed against the flow path forming layer 29 in the arranging step (S <b> 12), so that the first uneven portion 291 is formed along the first nozzle layer uneven portion 301 on the upper surface of the flow path forming layer 29. .

  Next, as in the first embodiment, the nozzle formation step (S9) is performed to form the nozzle 2. The nozzle 2 may be formed in advance on the layered material 31. Next, an ink supply port forming step (S8) is performed, and the ink supply port 10 is formed.

  As described above, the ink discharge unit 5 of the inkjet head substrate is formed by the manufacturing method according to the second embodiment. As in the first embodiment, the ink ejection unit 5 manufactured according to the present embodiment has the flow path forming layer 29 and the nozzle layer 30 in a state where the first uneven portion 291 and the first nozzle layer uneven portion 301 are aligned. And are in contact. For this reason, a contact area becomes large compared with the case where the flow path formation layer 29 and the nozzle layer 30 contact in a plane. Therefore, the adhesion strength between the flow path forming layer 29 and the nozzle layer 30 is increased. Therefore, the nozzle layer 30 can be made difficult to peel off from the flow path forming layer 29. In addition, the ink discharge unit 5 manufactured according to the present embodiment can obtain the same effects as those of the first embodiment. Moreover, the same deformation | transformation as 1st embodiment can be performed.

  In the second embodiment, when the shapes of the first nozzle layer uneven portion 301 and the second nozzle layer uneven portion 302 are changed, the shapes of the first mold uneven portion 331 and the second mold uneven portion 332 of the mold 33 are changed. That's fine. Moreover, you may form the site | part of the 2nd nozzle layer uneven | corrugated | grooved part 302 of the nozzle layer 30 in a plane by making the 2nd type uneven | corrugated | grooved part 332 into a plane.

  In addition, although the solution containing the material for forming the layered material 31 was dried and the layered material 31 was formed, it is not limited to this. For example, a layered material 31 in a semi-cured state (a state in which it is not completely cured and maintains a certain degree of softness) is formed on the upper surface of the mold 33 on which the first mold uneven portion 331 and the second mold uneven portion 332 are formed. And the first nozzle layer uneven portion 301 and the second nozzle layer uneven portion 302 may be formed by deforming the layered material 31. In this case, the layered material 31 on which the first nozzle layer uneven portion 301 and the second nozzle layer uneven portion 302 are formed is dried and cured to obtain a completed layered material 31. Further, for example, the first nozzle layer uneven portion 301 and the second nozzle layer uneven portion 302 may be formed by cutting the surface of the layered material 31 having a flat surface by machining such as cutting. At that time, for example, the surface roughness after cutting may be controlled in a position-selective manner by changing the curing progress of the layered material in a position-selective manner. Alternatively, the first nozzle layer uneven portion 301 and the second nozzle layer uneven portion 302 may be formed by processing the surface of the layered material 31 having a flat surface by etching, laser processing, or sand blasting.

  Further, when forming the first nozzle layer uneven portion 301 and the second nozzle layer uneven portion 302 in the layered material 31 in the uneven portion forming step (S11), the mold 33 may not be used. For example, you may form an uneven | corrugated | grooved part using the bar coater 40 (refer FIG. 14). As shown in FIG. 14, the bar coater 40 is formed by winding a metal wire around a cylindrical shaft portion (not shown) that is long in the left-right direction on the paper surface. When the metal wire is wound, the uneven portion 401 around the metal wire is formed.

  The case where the uneven | corrugated | grooved part formation process (S11) is performed using the bar coater 40 is demonstrated. As shown in FIG. 15, a viscous material 311 containing a material for forming the layered material 31 is disposed on a base 41 having a flat upper surface. Then, the bar coater 40 is moved in the left direction on the paper surface while the outer peripheral surface of the bar coater 40 is applied to the upper side of the arranged material 311 to extend the solution, thereby forming the material 311 to a predetermined thickness. At this time, a concavo-convex portion is formed on the upper surface of the material 311 along the concavo-convex portion 401 (see FIG. 14) due to the metal wire of the bar coater 40. The created uneven portions become the first nozzle layer uneven portion 301 and the second nozzle layer uneven portion 302. And the layered material 31 is formed by drying and hardening the material 311 in which the 1st nozzle layer uneven | corrugated | grooved part 301 and the 2nd nozzle layer uneven | corrugated | grooved part 302 were formed with the bar coater.

  In addition, the viscous material 311 containing the material for forming the layered material 31 is not extended by the bar coater 40, but the bar coater is formed on the surface of the semi-cured layered material containing the material for forming the layered material 31. The first nozzle layer uneven portion 301 and the second nozzle layer uneven portion 302 may be formed by moving the bar coater 40 while pressing 40. Then, the layered material 31 may be formed by drying and curing the semi-cured material.

  In the second embodiment, the flow path forming layer forming step (S3) corresponds to the “flow path layer forming step” of the present invention. The flow path forming layer forming step (S3) and the arranging step (S12) correspond to the “layer forming step” of the present invention.

DESCRIPTION OF SYMBOLS 1 Inkjet head substrate 2 Nozzle 3 Nozzle row 5 Ink discharge unit 10 Ink supply port 11 Ink flow path 29 Flow path forming layer 30 Nozzle layer 31 Layered material 39 Embedding material 291 First uneven portion 295 Wall portion 301 First nozzle layer uneven Part 302 Second nozzle layer uneven part 392 Second uneven part

Claims (16)

An inkjet head substrate comprising: a plurality of nozzles that eject ink; an ink supply port that supplies the ink; and an ink flow path that supplies the ink from the ink supply port to the nozzle,
A flow path forming layer that is a layer having a wall portion that forms at least a part of the ink flow path;
A layer formed on the flow path forming layer, the nozzle layer forming the nozzle; and
A first concavo-convex portion that is a concavo-convex portion provided at a portion in contact with the nozzle layer in the flow path forming layer;
A first nozzle layer concavo-convex portion that is a concavo-convex portion provided in a portion of the nozzle layer that contacts the flow path forming layer ;
A second nozzle layer concavo-convex portion, which is a concavo-convex portion provided at a portion in contact with the ink flow path in the nozzle layer ,
The substrate for an ink jet head, wherein the first uneven portion and the first nozzle layer uneven portion are aligned with each other. The surface roughness of the portion where the first nozzle layer uneven portion is provided, the ink-jet according to claim 1, wherein greater than the surface roughness of the portion where the second nozzle layer uneven portion is provided Head substrate. The plurality of nozzles are respectively arranged outside the ink supply port to form a nozzle row,
Said second nozzle layer uneven portion is a substrate for ink jet head according to claim 1 or 2, characterized in that it is formed by a plurality of grooves extending toward the ink supply port from the nozzle array. The plurality of nozzles are respectively arranged outside the ink supply port to form a nozzle row,
Said second nozzle layer uneven portion is an ink jet according to claim 1 or 2, characterized in that it is formed by a plurality of grooves extending along a direction perpendicular to the direction toward the ink supply port from the nozzle array Head substrate. An inkjet head substrate manufacturing method comprising: a plurality of nozzles that eject ink; an ink supply port that supplies the ink; and an ink flow path for supplying the ink from the ink supply port to the nozzle. And
A flow path layer forming step of forming a flow path forming layer that is a layer having a wall portion that forms at least a part of the ink flow path;
The nozzle layer, which is the layer in which the nozzle is formed, is formed on the flow path forming layer formed by the flow path layer forming step, and the unevenness provided at the portion in contact with the nozzle layer in the flow path forming layer A layer forming step of mutually aligning the first concavo-convex portion that is a portion and the first nozzle layer concavo-convex portion that is a concavo-convex portion provided in a portion that contacts the flow path forming layer in the nozzle layer ,
The layer forming step includes
An embedding step of disposing an embedding material, which is a material for embedding the ink channel, in a region including the ink channel formed by the wall portion of the channel forming layer formed by the channel layer forming step;
Cutting the flow path forming layer and the embedding material to form the first uneven portion by cutting in the flow path forming layer;
The nozzle layer is formed on a portion of the flow path forming layer and the embedding material cut by the cutting step, and the first uneven portion is formed on a portion of the nozzle layer that contacts the flow path forming layer. A nozzle layer forming step of forming the first nozzle layer irregularities along
With
A method of manufacturing an ink jet head substrate, further comprising a removing step of forming the ink flow path by removing the embedding material . In the cutting step, the flow path forming layer and the embedded material are cut to form the first uneven portion in the flow path forming layer, and the second uneven portion by cutting is formed in the embedded material,
In the nozzle layer forming step, the nozzle layer is formed, the first nozzle layer uneven portion is formed in a portion of the nozzle layer that contacts the flow path forming layer, and the nozzle layer contacts the embedding material. Forming a second nozzle layer concavo-convex portion, which is a concavo-convex portion along the second concavo-convex portion, at the site;
The inkjet according to claim 5 , wherein the removing step forms the ink flow path by removing the embedding material, and brings the second nozzle layer uneven portion into contact with the ink flow path. Manufacturing method of head substrate. In the cutting step, the flow path forming layer and the embedding material are cut so that the surface roughness of the portion where the first uneven portion is provided is larger than the surface roughness of the portion where the second uneven portion is provided. The method of manufacturing a substrate for an ink jet head according to claim 6 . A nozzle forming step of forming, in the nozzle layer, a nozzle row in which the plurality of nozzles are arranged so that the plurality of nozzles are arranged outside the ink supply port;
In the cutting step, the second uneven portion is formed by forming, in the embedding material, a plurality of grooves extending from a position where the nozzle row is disposed toward a position where the ink supply port is disposed. The method for manufacturing a substrate for an ink jet head according to claim 6 or 7 . A nozzle forming step of forming, in the nozzle layer, a nozzle row in which the plurality of nozzles are arranged so that the plurality of nozzles are arranged outside the ink supply port;
In the cutting step, a plurality of groove portions extending in a direction orthogonal to a direction from the position where the nozzle row is disposed to the position where the ink supply port is disposed are formed in the embedding material. method of manufacturing a substrate for ink jet head according to claim 6 or 7, characterized in that to form the. An inkjet head substrate manufacturing method comprising: a plurality of nozzles that eject ink; an ink supply port that supplies the ink; and an ink flow path for supplying the ink from the ink supply port to the nozzle. And
A flow path layer forming step of forming a flow path forming layer that is a layer having a wall portion that forms at least a part of the ink flow path;
The nozzle layer, which is the layer in which the nozzle is formed, is formed on the flow path forming layer formed by the flow path layer forming step, and the unevenness provided at the portion in contact with the nozzle layer in the flow path forming layer Forming a first uneven portion that is a portion and a first nozzle layer uneven portion that is an uneven portion provided in a portion of the nozzle layer that contacts the flow path forming layer;
With
The layer forming step includes
An uneven portion forming step of forming the first nozzle layer uneven portion on the nozzle layer formed of a layered material;
The nozzle layer in which the first nozzle layer uneven portion is formed by the uneven portion forming step is disposed on the flow path forming layer, and the first uneven portion is disposed along the first nozzle layer uneven portion. features and to Louis link method of manufacturing a substrate for jet head further comprising a disposing step of forming the layer. The concavo-convex portion forming step forms the first nozzle layer concavo-convex portion and the second nozzle layer concavo-convex portion which is an concavo-convex portion on the nozzle layer,
In the arranging step, the nozzle layer is arranged on the flow path forming layer, the first uneven portion is formed on the flow path forming layer, and the second nozzle layer uneven portion of the nozzle layer is formed on the ink flow. method of manufacturing a substrate for ink jet head according to claim 1 0, characterized in that arranged at a site in contact with the road. In the uneven portion forming step, the surface roughness of the portion where the first nozzle layer uneven portion is provided is larger than the surface roughness of the portion where the second nozzle layer uneven portion is provided. method of manufacturing a substrate for ink jet head according to claim 1 1, characterized by forming said as one nozzle layer uneven portion second nozzle layer uneven portion. A nozzle forming step of forming, in the nozzle layer, a nozzle row in which the plurality of nozzles are arranged so that the plurality of nozzles are arranged outside the ink supply port;
In the uneven portion forming step, the second nozzle layer uneven portion is formed by forming, in the nozzle layer, a plurality of groove portions extending from a position where the nozzle row is disposed toward a position where the ink supply port is disposed. method of manufacturing a substrate for ink jet head according to claim 1 1 or 1 2, characterized in that to form the. A nozzle forming step of forming, in the nozzle layer, a nozzle row in which the plurality of nozzles are arranged so that the plurality of nozzles are arranged outside the ink supply port;
In the uneven portion forming step, a plurality of groove portions extending in a direction orthogonal to a direction from the position where the nozzle row is disposed toward the position where the ink supply port is disposed are formed in the nozzle layer. method of manufacturing a substrate for ink jet head according to claim 1 1 or 1 2 and forming a nozzle layer uneven portion. The molecular weight of the material of the flow path forming layer formed by the flow path layer forming process is smaller than the molecular weight of the embedded material disposed by the embedding process,
In the cutting step, the flow path forming layer and the embedding material having different molecular weights are cut so that the surface roughness of the portion where the first uneven portion is provided is the surface of the portion where the second uneven portion is provided. 8. The method of manufacturing an ink jet head substrate according to claim 7 , wherein the flow path forming layer and the embedding material are cut so as to be larger than roughness. The Young's modulus of the material of the flow path forming layer formed by the flow path layer forming step is smaller than the Young's modulus of the embedded material disposed by the embedding step,
In the cutting step, by cutting the flow path forming layer and the embedding material having different Young's moduli, the surface roughness of the portion where the first uneven portion is provided is the portion where the second uneven portion is provided. to be larger than the surface roughness, method of manufacturing a substrate for ink jet head according to claim 7 or 1 5, characterized in that cutting said burying material and the channel forming layer.

Images