JP2008087475A - Liquid discharge head and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording head increasing the refilling speed, stabilizing the discharged amount of droplets, and improving the discharge efficiency of the droplets and to provide its manufacturing method. <P>SOLUTION: In a side-shooter-type inkjet recording head, with respect to one bubble chamber 12, a first ink channel 13 and a second ink channel 14 connected from an ink supply opening are independently provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid discharge head that discharges liquid and a method for manufacturing the same, and more particularly to an ink jet recording head that performs recording by discharging ink onto a recording medium and a method for manufacturing the same.

  As an example of using a liquid discharge head that discharges liquid, there is an ink jet recording system that performs recording by discharging ink onto a recording medium.

  An ink jet recording head applied to an ink jet recording method generally includes a plurality of energy generating elements that generate energy used for discharging a fine discharge port, a liquid flow path, and a liquid provided in a part of the liquid flow path. I have. Conventionally, as a method of manufacturing such an ink jet recording head, there is a method example described in Patent Document 1.

  A method of manufacturing the ink jet recording head described in the above publication will be described with reference to FIGS. 1 (A) to 1 (F).

  First, as shown in FIGS. 1A and 1B, ink is dissolved in a resin that can be dissolved on a substrate 1 including an electrothermal conversion element 2 as an energy generation element that generates energy for discharging a liquid. A pattern 4 serving as a mold for forming a flow path is formed.

  A desired number of electrothermal conversion elements 2 are arranged on the substrate 1. When the electrothermal conversion element 2 generates heat, bubbles grow in the ink in contact with the electrothermal conversion element 2, and ink droplets are ejected with the foaming energy.

  The electrothermal conversion element 2 is connected to a control signal input electrode (not shown) for operation. In general, various functional layers such as a protective layer covering the electrothermal conversion element 2 are provided on the substrate for the purpose of improving the durability of the electrothermal conversion element 2.

  The ink flow path pattern 4 is patterned by a photolithography technique after a soluble positive photosensitive resist film is formed by spin coating.

  As the above-mentioned photosensitive resist material, a vinyl ketone photodegradable polymer compound such as polymethyl isopropyltone or polyvinyl ketone can be suitably used.

  Next, as shown in FIG. 1C, a coating resin layer 5 and a water repellent material 6 are further formed on the dissolvable resin material layer on which the ink flow path pattern 4 is formed by a spin coating method.

  Here, as the coating resin layer 5, a photosensitive layer is used because the ink discharge ports 7 must be easily and accurately formed by photolithography. In addition, since high mechanical strength as a structural material of the recording head, adhesion to the substrate 1, ink resistance, and resolution for patterning a fine pattern of the ink discharge port 7 are required at the same time, epoxy is required. A cationic polymerization cured product of the resin is used.

  Next, as shown in FIG. 1D, pattern exposure is performed on the photosensitive coating resin layer 5 and the water repellent material 6 as described above through the mask 10 to form the ink discharge ports 7. .

  The photosensitive coating resin layer 5 is a negative type, and a portion where the ink discharge port 7 is formed is shielded with a mask (of course, a portion where electrical connection is made is also shielded, not shown).

  All the processes up to now can be aligned using conventional photolithography technology, which is much more accurate than the method in which an orifice plate (plate on which discharge ports are formed) is separately prepared and bonded to the substrate 1. Can be improved. The photosensitive coating resin layer 5 that has been subjected to pattern exposure in this manner may be subjected to heat treatment in order to accelerate the reaction as necessary. Here, as described above, since the photosensitive coating resin layer 5 is made of an epoxy resin that is solid at room temperature, diffusion of the cationic polymerization initiating species generated by pattern exposure is restricted, and excellent patterning accuracy and shape are achieved. Can be realized. Next, the pattern-exposed photosensitive coating resin layer 5 is developed using an appropriate solvent to form an ink discharge port 7.

  Thus, the flow path forming member (the coating resin layer 5 in which the ink flow path wall and the ink discharge port 7 are formed) is produced.

  Next, as shown in FIG. 1 (E), a protective material 8 such as cyclized rubber is used so that the flow path forming member produced above is not damaged, and is opposite to the substrate 1 in the flow path forming member. The side where the ink discharge port 7 is opened is protected. Then, a resist pattern or the like is formed on the back side of the substrate 1 (the side opposite to the side on which the electrothermal conversion element 2 is disposed) and chemically etched to form the ink supply port 9.

  Finally, as shown in FIG. 1 (F), the soluble resin 4 that forms the ink flow path is eluted with a solvent.

Electrical connection (not shown) for driving the ink supply member and the electrothermal conversion element 2 is performed on the substrate 1 formed with the ink flow path and the ink discharge port thus formed. An ink jet recording head is produced.
US Pat. No. 5,478,606

  In recent printers, higher image quality and higher definition have been demanded. For this reason, the ink discharge port has been miniaturized for the purpose of reducing the size of the ink droplets. The space that contains the energy generating elements in a part of the ink flow path and communicates with the discharge port (hereinafter, this space is referred to as the discharge unit). Must be reduced in volume).

  However, in the above prior art, the height of the ejection part and the ink flow path are the same height, and if the height of the ejection part is lowered, the ink flow path becomes narrower. The speed (ink filling speed into the energy generating element chamber) becomes slow. For this reason, the ink may be ejected before the ejection portion is filled with the ink, which causes a problem that the ejection amount of the ink droplet varies.

  Further, if the width of the ink flow path is increased in order to improve the refill speed, the discharge ports cannot be arranged with high density. For this reason, no matter how much the smallest ink droplets are ejected, the printing speed is extremely lowered, and the ejection efficiency is lowered.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid discharge head capable of increasing the refill speed and stabilizing the droplet discharge amount and improving the droplet discharge efficiency, and a method for manufacturing the same.

  The manufacturing method of the liquid discharge head as an example of the present invention is as follows.

  A method of manufacturing a liquid discharge head having a discharge port for discharging a liquid and a flow path forming member that forms a flow path for the liquid communicating with the discharge port includes the following steps. A step of forming a first pattern for forming the flow path on the substrate; a step of forming a first covering layer so as to cover the first pattern; A step of partially removing the covering layer to expose the first pattern; Further, a step of forming a second pattern for forming the flow path on the coating layer so as to contact the exposed first pattern, and removing the first and second patterns Forming the flow path.

  Further, the liquid discharge head according to the present invention has a configuration in which a plurality of ink flow paths are independently provided for one discharge portion, or the flow paths are arranged on the substrate via a flow path forming member. It is an overlapped form.

  According to the present invention as described above, it is possible to increase the refill speed and to stabilize the ejection amount of the ejected droplets. Accordingly, it is possible to provide a liquid discharge head that improves the discharge efficiency of droplets.

  Embodiments of the present invention will be described below with reference to the drawings.

  The liquid discharge head can be mounted on an apparatus such as a printer, a copying machine, a facsimile having a communication system, a word processor having a printer unit, or an industrial recording apparatus combined with various processing apparatuses. For example, it can be used for applications such as biochip creation, electronic circuit printing, and drug ejection.

  By using this liquid discharge head, recording can be performed on various recording media such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, and ceramics. Note that “recording” used in the present specification not only applies an image having a meaning such as a character or a figure to a recording medium but also an image having no meaning such as a pattern. I mean.

  Further, the term “liquid” is to be interpreted widely, and is applied to a recording medium to form an image, a pattern, a pattern, or the like, process the recording medium, or process ink or recording medium. It shall refer to the liquid provided. Here, as the treatment of the ink or the recording medium, for example, the fixing property is improved by coagulation or insolubilization of the coloring material in the ink applied to the recording medium, the recording quality or coloring property is improved, and the image durability is improved. Say that.

  Moreover, in the following description, the same number is attached | subjected to the structure which has the same function in drawing, and the description may be abbreviate | omitted.

  FIG. 3 is a schematic perspective view of the liquid discharge head according to the embodiment of the present invention. As shown in FIG. 3, the liquid discharge head of the present invention is formed with an energy generating element (not shown) for generating energy used for discharging the liquid and a discharge port 7 for discharging the liquid corresponding thereto. Has been. In this embodiment, a member that forms the discharge port 7 is integrated with a flow channel forming member 5 that forms a flow channel (not shown) communicating with the discharge port. As the substrate 1, for example, a Si wafer having a crystal axis (100) can be used.

  FIGS. 2-1 and 2-2 are cross-sectional views taken along the line A-A 'of FIG.

  2A and 2B show a method for manufacturing the liquid discharge head according to the embodiment of the present invention. Hereinafter, the manufacturing method of the present embodiment will be described in detail along FIGS. 2-1 and (A) to (H) of FIG.

  First, as shown in FIG. 2A, a first pattern 4 serving as a mold for forming a flow path is formed on a silicon substrate 1 including an energy generating element 2.

  In this embodiment, an electrothermal conversion element is used as the energy generating element, but there is no problem even if a piezoelectric element is used. When an electrothermal conversion element is used as the operating principle of these elements, the element heats a nearby liquid, thereby causing a state change in the liquid and generating discharge energy. For example, when a piezoelectric element is used, ejection energy is generated by mechanical vibration of the element. These elements are connected to control signal input electrodes (not shown) for operating these elements. In general, for the purpose of improving the durability of these energy generating elements, various functional layers such as a protective layer covering the energy generating elements are provided on the substrate. Of course, such a functional layer is provided. There is no problem in one direction.

  As the resist material to be the first flow path pattern 4, a photosensitive material is desired in order to accurately pattern the positional relationship with the electrothermal conversion element 2. In this embodiment, polymethyl isopropenyl ketone (PMIPK) is used as a positive resist (positive photosensitive resin). As a method for forming the resist layer, there is a method in which it is dissolved in an appropriate solvent and a film is formed by a spin coating method, a roll coating method or the like. At this time, PMIPK was exposed with ultraviolet light of 260 nm to 300 nm in the photosensitive wavelength region.

  Next, as shown in FIG. 2B, on the dissolvable resin material layer (first positive photosensitive resin) constituting the first flow path pattern 4, a flow path forming member is further formed. The first covering resin layer 5A to be a part is formed by a spin coat method, a roll coat method or the like. Then, pattern exposure is performed on the coating resin layer 5 </ b> A through the mask 10, thereby forming a communication portion (channel portion) 17 between the discharge port 7 and the second flow path 14. The first pattern 4 is partially exposed from the communicating portion.

  Here, in the step of forming the covering resin layer 5A, characteristics such as not deforming the first flow path pattern 4 with a soluble resin are required. That is, when the coating resin layer 5A is dissolved in a solvent and formed on the first flow path pattern 4 by spin coating, roll coating, or the like, the solvent is selected so as not to dissolve the first flow path pattern 4. There is a need.

  The coating resin layer 5A is required to have high mechanical strength as a structural material for the flow path wall, adhesion to the substrate 1, and solvent resistance. In addition, a photosensitive material that can be formed by photolithography in order to accurately pattern the positional relationship between the communication portion with the discharge port and the energy generating element 2 is desirable. Furthermore, since the first flow path pattern 4 made of a soluble resin has to be completely covered, it must be coated with a corresponding thickness.

  Here, as a result of intensive studies, as shown in the following resin composition 1, the cationic polymerization cured product of epoxy resin has excellent strength, adhesion, and solvent resistance as a structural material, and the epoxy resin is at room temperature. It has been found that if it is solid, it has excellent patterning characteristics. Further, in order to form by spin coating, the following resin composition 1 was dissolved in a methyl isobutyl ketone / xylene mixed solvent at a concentration of 60 wt%.

Resin composition 1
Name Manufacturer Weight part (wt%)
EHPE-3150 Daicel Chemical Industries, Ltd. 100
A-187 Nihon Unicar Co., Ltd. 5
SP-170 Asahi Denka Kogyo Co., Ltd. 2

Furthermore, additives and the like can be appropriately added to the resin composition 1 as necessary. For example, a flexibility-imparting agent may be added for the purpose of lowering the elastic modulus of the epoxy resin, or a silane coupling agent may be added to obtain further adhesion to the substrate 1.

  At this time, the first flow path pattern 4 must be patterned in a wavelength region or exposure amount that is not sensitized.

  Next, as shown in FIGS. 2-1 (C) and (D), the second pattern 3 for forming the second flow path is formed on the coating resin layer 5A (on the first coating layer). Form.

  As the soluble resin (second positive photosensitive resin) constituting the second flow path pattern 3, a positive resist 11 called PMMA was used. PMMA is a radical polymerization of methyl methacrylate (MMA) and methacrylic acid (MAA) to polymerize a binary copolymer (P (MMA-MAA) = 90 to 70:10 to 30) with a cyclohexanone solvent. It is dissolved.

  FIG. 9 shows a chemical reaction formula for forming a thermally crosslinked film by dehydration condensation reaction of this PMMA binary copolymer (P (MMA-MAA)). In this dehydration condensation reaction, a stronger crosslinked film can be formed by heating at 180 to 200 ° C. for 30 to 120 minutes. This crosslinked film is a solvent-insoluble type, but is a positive type resist that is solvent-soluble only in a portion irradiated with an electron beam such as DUV light. In particular, this PMMA is sensitive to ultraviolet light having a photosensitive wavelength region of less than 260 nm, whereas PMIPK is sensitive to ultraviolet light having a photosensitive wavelength region of 260 nm to 300 nm, so that selective exposure is possible depending on the exposure wavelength. Here, as the second positive photosensitive resin, a covalent polymer obtained by polymerizing methacrylic acid to the main component methyl methacrylate is shown, but a methacrylic acid anhydride may be used instead of the methacrylic acid. Good.

  As shown in FIG. 2C, the positive resist 11 is partly separated from the first pattern by the covering resin layer 5A, and comes into contact with the first pattern through the communication portion described above. In this example, the first pattern 4 is in contact at two points on the path from the supply port 9 to the energy generating element 2.

  Next, as shown in FIG. 2D, using an exposure apparatus that irradiates DUV light, a filter that blocks ultraviolet light having a wavelength of 260 nm or more is attached to the exposure apparatus as a wavelength selection unit, and the wavelength is less than 260 nm. The resist 11 is irradiated with only ultraviolet light. Thus, the second flow path pattern 3 can be formed without exposing the first flow path pattern 4 to light.

  Next, as shown in FIGS. 2-2 (E) and (F), the second photosensitive coating resin layer 5B used in the second step is applied, and pattern exposure is performed through the mask 10. Thus, the discharge port 7 is formed. In this example, the discharge port 7 is formed in the second coating layer 5A, but the position where the discharge port is formed may be the first coating layer 5B. The photosensitive coating resin layer 5B used in this step is the same as the resin composition 1 applied in the second step from the viewpoint of adhesion, mechanical strength, etc. (that is, a cationically polymerizable compound and a photocationic polymerization initiator). Negative-type photosensitive resin). However, if the adhesiveness with the lower coating resin layer, the mechanical strength, and the patternability can be satisfied, they need not be the same.

  In the present embodiment, a water repellent material (not shown) that can be patterned simultaneously with the coating resin layer 5 is used on the coating resin layer 5 in order to improve ejection stability. The water repellent material can be formed by a method of forming a liquid by curtain coating (direct coating) or a method of forming a dry film by lamination. This water repellent material is the same as the water repellent material 6 shown in FIG. Further, the patterning of the discharge port 7 must be performed accurately with respect to the position of the communication portion with the discharge port formed in the second step.

  Next, as shown in FIG. 2G, a supply port 9 that is an opening for supplying a liquid was formed in the substrate 1 by anisotropic etching of silicon by TMAH. At this time, the protective material 8 such as cyclized rubber is used so that the water repellent material produced in the fifth step and the coating resin layer 5 as the flow path forming member are not damaged, and the substrate 1 in the flow path forming member. The surface opposite to the side where the discharge port 7 opens is protected. After forming the supply port 9, the protective material 8 is removed.

  Finally, as shown in FIG. 2H, the first and second flow path patterns 4 and 3 that can be dissolved by the solvent are eluted. The elution is easily performed by immersing the substrate 1 on which the flow path forming member is configured in a solvent or wiping the solvent with a spray. Moreover, elution time can be further shortened by using ultrasonic waves or the like together.

  Attachment of a member for supplying liquid and electrical connection of an electric wiring member for driving the electrothermal conversion element 2 to the substrate 1 having the flow path and the discharge port thus formed (not shown). To complete the liquid discharge head.

  According to the manufacturing method described above, various shapes of flow paths can be obtained by devising the shape and positional relationship of the first pattern 4 and the second pattern 3, and the contact portion between the first pattern and the second pattern. Can be formed. Next, an example of a liquid discharge head that can be manufactured by the method of manufacturing a liquid discharge head according to the present invention will be described.

(Embodiment 1)
4A to 4C show a liquid discharge head according to Embodiment 1 of the present invention. 4A is a schematic plan perspective view of the head of this embodiment, FIG. 4B is a cross-sectional view taken along the line IVB-IVB in FIG. 4A, and FIG. 4C is an IVC in FIG. FIG.

  The liquid discharge head according to the present embodiment includes one discharge portion (a space including each energy generating element 2) 12 communicating with the discharge port 7, a first flow path 13 and a second flow passage communicating with the discharge portion. And a flow path 14. The first flow path 13 extends from the supply port 9 (see (H) in FIG. 2-2) to the discharge unit 12 so as to be in contact with the formation surface of each energy generating element 2 of the substrate 1. The second flow path 14 is arranged substantially in parallel with the first flow path 13 so as to overlap with the flow generation member 5 above the formation surface of the energy generating element 2, and the first flow path 13 extends from the supply port 9 to the discharge section. Moreover, although the discharge outlet 7 is provided in the position facing the energy generating element 2, this invention is not limited to this.

  Moreover, in this embodiment, the discharge part 12 has taken the shape from which a cross-sectional area parallel to a board | substrate changes in steps. As shown in FIG. 4B, the discharge unit 12 includes a first discharge unit 15 close to the energy generating element 2 and a smaller cross-sectional area parallel to the substrate 1 than the first discharge unit 15. And a second discharge portion 16 close to the 7 side. The discharge port 7 has a smaller cross-sectional area parallel to the substrate 1 than the second discharge port portion 16. The first discharge section 15 is accessed by the first flow path 13, and the second discharge section 16 is accessed by the second flow path 14. In this example, the first discharge unit 15 and the second discharge unit 16 are set at a position where the cross-sectional area parallel to the substrate of the discharge unit 12 becomes small (position D in the drawing). The height of the first discharge unit 15 (the direction from the substrate 1 toward the discharge port 7) is equal to the height of the first flow path 13. In addition, the relationship between each structure and component such as the discharge unit, the discharge port, and the flow path described above can be commonly used in the second and subsequent embodiments. Of course, the present invention is not limited to this.

  In such a head, when a droplet is ejected, the liquid is pushed out to the ejection port 7 side and the supply port 9 side by the pressure of the bubble growing by the heat generated by the energy generating element 2. At this time, since the distance L from the formation surface of the energy generating element 2 on the substrate 1 to the opening surface of the discharge port 7 in the flow path forming member is very short in order to reduce the dots of the discharge liquid, the generated bubbles are discharged. The liquid meniscus at the outlet 7 is broken to communicate with the outside. Then, for example, 1 microliter droplet is discharged from the discharge port 7. When the bubbles communicate with the atmosphere as described above, stable discharge is possible because the flow resistance on the discharge port 7 side is lower than the flow resistance pushed on the supply port 9 side. Further, when the liquid is refilled (refilled) from the first and second flow paths 13 and 14 to the discharge unit 12, in addition to the refill from the first flow path 13, the refill from the second flow path 14 is performed. Will be refilled quickly.

  Thus, even if the cross section of the first flow path 13 becomes narrower along with the volume of the discharge section 12 in order to shorten the distance L, it has the second flow path 14 separately connected to the discharge section 12, There is no worry that the refill speed will decrease. For this reason, the problem that the liquid is discharged before the discharge portion 12 is filled and the discharge amount varies is solved.

  Further, the flow path width of the first flow path 13 is widened within a range in which the predetermined arrangement density of the discharge ports 7 can be maintained, and if the desired refill speed is still not satisfied, the flow width of the second flow path 14 can be used. There is also an advantage of being good.

(Embodiment 2)
5A to 5C show a liquid discharge head according to the second embodiment of the present invention. 5A is a schematic plan perspective view of the head of the present embodiment, FIG. 5B is a VB-VB cross-sectional view of FIG. 5A, and FIG. 5C is a VC of FIG. 5A. -VC is a sectional view.

  The difference from the first embodiment described above is that, in addition to the flow channel configuration of the first embodiment, a plurality of second flow channels 14 are formed in a row and communicated with both of the adjacent discharge sections 12. Is a point. The other points are the same as those in the first embodiment. Even in such a head, the same operations and effects as the head of the first embodiment can be obtained. In particular, when liquid is simultaneously discharged from several discharge ports 7, refill can be performed also from the discharge unit 12 communicating with the discharge ports 7 that are not discharged between them, so that the refill speed is higher than that of the head of the first embodiment. Is thought to improve.

(Embodiment 3)
6A to 6C show a liquid discharge head according to Embodiment 3 of the present invention. 6A is a schematic plan perspective view of the head of this embodiment, FIG. 6B is a cross-sectional view taken along VIB-VIB in FIG. 6A, and FIG. 6C is a VIC in FIG. 6A. -VIC sectional drawing.

  The difference from the first embodiment is that the second flow path 14 passes through the flow path walls formed between the adjacent discharge sections 12 and between the first flow paths 13. It is a point connected to. The other points are the same as in the first embodiment. The second flow path 14 accesses the discharge unit 12 from the downstream side in the liquid supply direction (the direction from the supply port toward the energy generating element) in the first flow path 13. When viewed from the discharge port 7 toward the substrate 1, the second flow path 14 is disposed above the first flow path 13 via the flow path forming member 5 as in the first embodiment. Not. Even in such a head, the same operations and effects as the head of the first embodiment can be obtained. In particular, this form is effective for shortening the distance L from the surface of the substrate 1 where the energy generating element 2 is formed to the opening surface of the discharge port 7 of the flow path forming member to reduce the size of the discharge liquid. .

(Embodiment 4)
7A to 7C show a liquid discharge head according to Embodiment 4 of the present invention. FIG. 7A is a schematic plan perspective view of the head of this embodiment, FIG. 7B is a sectional view taken along the line VIIB-VIIB in FIG. 7A, and FIG. 7C is a VIIC in FIG. It is -VIIC sectional drawing.

  The difference from the first embodiment is that the adjacent ejection units 12 are connected as in the second embodiment. In addition, as in the third embodiment, the second flow path 14 passes through the flow path wall formed between the adjacent first flow paths 13 and connects the adjacent discharge units 12. It is a point connected to the part. The other points are the same as in the first embodiment. Even in such a head, the same operations and effects as the head of the first embodiment can be obtained. In particular, this embodiment has the effects of the second embodiment and the third embodiment.

(Embodiment 5)
8A to 8C show a liquid discharge head according to Embodiment 5 of the present invention. 8A is a schematic plan perspective view of the head of this embodiment, FIG. 8B is a cross-sectional view taken along the line VIIIB-VIIIB in FIG. 8A, and FIG. 8C is the VIIIC in FIG. -VIIIC sectional drawing, FIG.8 (D) is VIIID-VIIID sectional drawing of FIG. 8 (A).

  In this type of liquid ejection head, on one side of the supply port, the discharge units 12 communicating with the discharge port 7 are arranged in a zigzag manner, with the distance to the supply port 9 being short and the distance being long. The density of the discharge port array is increased. Corresponding energy generating elements are similarly arranged in a staggered manner. Discharge ports and discharge portions closer to the supply port 9 are designated as 7A and 12A, respectively, and those far from the supply port 9 are designated as 7B and 12B, respectively. The relationship between the first and second ejection units in the ejection unit 12 is the same as that in the first embodiment.

  As this form, the 2nd flow path 14 is the flow path wall formed between the adjacent discharge parts 12 and the 1st flow path 13 in one discharge port row | line | column (BB 'line direction). It passes through and is connected to each discharge section 12 in the other discharge port array (AA ′ line direction). In the case of this embodiment, when viewed from the discharge port 7 toward the substrate 1, the second flow path 14 overlaps a part of the discharge portion 12 </ b> A corresponding to the discharge port 7 </ b> A via the flow path forming member 5. Are arranged as follows.

  The second flow path 14 is formed relatively upward (on the discharge port side) with respect to the first flow path 13. Further, the mutual positional relationship between the first flow path 13 and the first flow path 14 can be reversed from the above example. That is, the first flow path 13 corresponding to the discharge port 7A closer to the supply port 9 is on the discharge port side, and the second flow path corresponding to the discharge port 7B farther from the supply port 9 is provided. It is also possible to adopt a configuration in which 14 is arranged on the substrate side. Also, relatively large droplets are ejected from the discharge port 7A closer to the supply port 9 than the discharge port, and relatively small droplets are ejected from the discharge port 7B far from the supply port 9. When discharging, it is preferable to make the cross-sectional area of the first flow path 13 larger than the cross-sectional area of the second flow path 14. Further, the second flow path 14 may access either the first discharge portion 15B or the second discharge portion 16B in the discharge port portion 12B.

  When the flow path of this embodiment is created, in the manufacturing method described above, the first pattern 4 and the second pattern 3 are in contact with the upstream side (supply port side) in the supply direction from the discharge port 7A. However, no contact is made downstream (on the discharge port 7B side).

  In this embodiment, the first flow path 13 and the second flow path 14 are overlapped via the flow path forming member 5, so that the adhesion force between the substrate 1 and the flow path forming member 5 is not impaired. The cross-sectional area of both flow paths can be increased. Furthermore, when the second flow path 14 is arranged so as to overlap the first flow path 13 in addition to the discharge portion 12A in the direction from the discharge port 7 toward the substrate 1, the above-described effect is obtained. Becomes even bigger.

It is typical sectional drawing regarding the manufacturing method of the conventional inkjet recording head. It is typical sectional drawing which shows an example of the manufacturing method of the liquid discharge head of this invention. It is typical sectional drawing which shows the process after the process of (D) of FIGS. It is a typical perspective view showing an example of the liquid discharge head of the present invention. FIG. 2 is a schematic plan view and a cross-sectional view of a liquid discharge head according to Embodiment 1 of the present invention. FIG. 6 is a schematic plan view and a cross-sectional view of a liquid ejection head in Embodiment 2 of the present invention. It is the schematic plan view and sectional drawing of a liquid discharge head in Embodiment 3 of this invention. FIG. 6 is a schematic plan view and a cross-sectional view of a liquid ejection head in Embodiment 4 of the present invention. FIG. 9 is a schematic plan view and a cross-sectional view of a liquid discharge head according to a fifth embodiment of the present invention. It is a chemical reaction formula showing a chemical change of a positive resist by light irradiation.

Explanation of symbols

1 Substrate 2 Energy generating element (electrothermal conversion element)
3 Second flow path pattern (PMMA positive resist)
4 First flow path pattern (PMIPK positive resist)
5 Flow path forming member Covering resin layer (negative resist made of epoxy resin cation polymerization)
6 Water repellent material 7 Discharge port 8 Protective film 9 Supply port 10 Mask 11 Positive resist layer 12 Discharge portion 13 Ink channel (first ink channel)
14 Sub-ink channel (second ink channel)

Claims (13)

A liquid discharge head manufacturing method comprising: a discharge port for discharging a liquid; and a flow path forming member that forms a flow path for the liquid communicating with the discharge port,
Forming a first pattern of a part of the flow path on the substrate;
Forming a first covering layer to be the flow path forming member so as to cover the first pattern;
Removing a portion of the first covering layer to partially expose the first pattern;
Forming a second pattern on a part of the flow path on the first covering layer so as to come into contact with the exposed first pattern;
Forming a second coating layer to be the flow path forming member so as to cover the second pattern;
And a step of forming the flow path by removing the first and second patterns.   The method of manufacturing a liquid ejection head according to claim 1, wherein the first pattern and the second pattern are in contact at a plurality of locations.   The first coating layer and the second coating layer are layers of a negative photosensitive resin, and the first pattern and the second pattern are formed of a positive photosensitive resin, A method of manufacturing a liquid discharge head according to claim 1 or 2.   The wavelength range of the first positive photosensitive resin that forms the first pattern is different from the wavelength range of the second positive photosensitive resin that forms the second pattern. The method of manufacturing a liquid discharge head according to claim 3.   5. The liquid ejection according to claim 4, wherein the first positive photosensitive resin is mainly sensitive to a wavelength of 260 nm or more, and the second positive photosensitive resin is mainly sensitive to a wavelength of less than 260 nm. Manufacturing method of the head.   The first positive photosensitive resin has polymethyl isopropenyl ketone as a main component, and the second positive photosensitive resin has methyl methacrylate as a main component and methacrylic acid or methacrylic anhydride having a covalent weight. The method of manufacturing a liquid ejection head according to claim 4, wherein the liquid ejection head is a combined body. A substrate on which an element for generating energy used for discharging the liquid is formed; a discharge port provided corresponding to the element for discharging the liquid; and a supply port for supplying the liquid used for discharge; In a liquid discharge head having a discharge portion communicating with the discharge port, and a flow path communicating the discharge portion and the supply port,
The flow path corresponding to the discharge port disposed at a position relatively far from the supply port, and the discharge unit corresponding to the discharge port disposed at a position relatively close to the supply port, A liquid discharge head, wherein the liquid discharge head is disposed so as to overlap in a direction from the discharge port toward the substrate.   Two flow paths corresponding to two discharge ports corresponding to two adjacent discharge ports arranged at positions relatively close to the supply port correspond to the discharge ports arranged at positions relatively far from the supply port. The liquid discharge head according to claim 7, wherein the liquid discharge head is interposed.   The flow path corresponding to the discharge port arranged at a position relatively close to the supply port is compared with the flow path corresponding to the discharge port arranged at a position relatively far from the supply port, The liquid discharge head according to claim 7, wherein the liquid discharge head is disposed at a position close to the substrate.   The flow path corresponding to the discharge port disposed at a position relatively far from the supply port, and the flow path corresponding to the discharge port disposed at a position relatively close to the supply port, The liquid discharge head according to claim 7, wherein the liquid discharge head is disposed so as to overlap in a direction from the discharge port toward the substrate. A substrate on which an element for generating energy used for discharging the liquid is formed; a liquid discharge port provided at a position facing the element; a supply port for supplying a liquid used for discharge; In a liquid discharge head having a discharge portion that communicates with a discharge port, and a flow path forming member that forms a flow path that connects the discharge portion and the supply port.
The flow path includes first and second flow paths,
The first flow path and the second flow path overlap at least from the supply port to the discharge portion via the flow path forming member in the direction from the discharge port toward the substrate. The liquid discharge head is characterized in that the first flow path is closer to the substrate than the second flow path.   The discharge section has a cross-sectional area parallel to the substrate and is formed by a first discharge section that is relatively close to the substrate and a second discharge section that is relatively far from the substrate. The liquid discharge head according to claim 11, wherein a flow path communicates with the first discharge section, and the second flow path communicates with the second discharge section.   The plurality of sets of the energy generating elements and the discharge units corresponding to the energy generating elements are formed in a row, and the second flow path communicates with both adjacent discharge units. 11. A liquid discharge head according to item 11.

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