Liquid discharge head and method for manufacturing the same

Abstract

To provide a liquid discharge head which prevents flowing from a coating position of a sealing material, and has high electric reliability.SOLUTION: A liquid discharge head has an electric board including an element for discharging a liquid, a flow channel formation member having a pressure chamber and a discharge port which communicates with the pressure chamber and discharges the liquid, and a pad array where a plurality of pads electrically connected to the element are arrayed along one side of the substrate, on a first surface of a substrate, an electric wiring board connected to the pad through an electric connection part, and a sealing material arranged on the first surface of the substrate so as to cover the electric connection part, wherein the flow channel formation member has an opening, and the pad is positioned in the opening, when the element substrate is viewed in plan view.SELECTED DRAWING: Figure 17

Description

[Technical field]

[0001] The present invention relates to a liquid ejection head and a manufacturing method thereof. [Background technology]

[0002] A liquid ejection head provided in a liquid ejection device such as an inkjet printer has an element substrate equipped with elements that pressurize the liquid, and a nozzle plate equipped with ejection ports. The liquid pressurized by driving the elements is ejected from the ejection ports as droplets to the outside of the head. The element substrate on which the elements are formed is formed with electrodes (electrode pads, etc.) that are electrically connected to an electric wiring board to supply power from the outside to drive the elements. Electrical connection parts such as wires and inner leads that connect the electrodes and the electric wiring board are sealed with a sealant such as a resin material to prevent ink from adhering to them. The electrical connection parts are covered by applying a sealant to the electrical connection parts and curing the applied sealant by heating or the like.

[0003] However, if the sealant flows from the application position on the element substrate, it may not be possible to sufficiently cover the electrical connection portion. Therefore, there is a liquid ejection head in which a member that acts as a wall to prevent the sealant from flowing is provided on the element substrate. For example, Patent Document 1 discloses a liquid ejection head in which an insulating member is disposed between an electrode pad row on the element substrate and an edge of the substrate corresponding to the electrode pad row. The insulating member in Patent Document 1 is made of the same material as an adhesive layer formed between the element substrate and the nozzle plate to improve the adhesiveness between the element substrate and the nozzle plate, and is formed by photolithography at the same time. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-733 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the liquid ejection head described in Patent Document 1, a wall is formed by using an adhesive layer to prevent the sealant from flowing out of the element substrate. However, since the adhesive layer is generally low in height, if the amount of sealant applied increases, it may overflow the wall and overflow outside the element substrate. If the sealant flows, bubbles may be trapped in the sealant, and the bubbles may expand when the sealant is thermally cured, leading to the exposure of the electrical connection.

[0006] In view of the above problems, the present invention aims to provide a liquid ejection head with high electrical reliability by forming a wall for suppressing the flow of sealant using a flow path forming member for forming a flow path on an element substrate, thereby making it easier to prevent the sealant from flowing away from the application position. [Means for solving the problem]

[0007] The present invention, which achieves the above-mentioned object, is a liquid ejection head comprising an element substrate provided on a first surface of a substrate, the element substrate having an element for ejecting liquid, a flow path forming member having a pressure chamber and an ejection port communicating with the pressure chamber for ejecting liquid, and a pad row in which a plurality of pads electrically connected to the element are arranged along one side of the substrate, an electrical wiring board connected to the pads via electrical connection parts, and a sealant arranged on the first surface of the substrate so as to cover the electrical connection parts, wherein, when the element substrate is viewed in a plane, the flow path forming member has an opening, and the pad is located within the opening. Effect of the Invention

[0008] According to the present invention, it is possible to provide a liquid ejection head that is highly electrically reliable and prevents the sealant from flowing away from the application position. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram showing a liquid ejection apparatus according to an embodiment of the present invention; [Diagram 2] FIG. 1 is a conceptual diagram showing a control system according to an embodiment of the present invention. [Diagram 3]FIG. 2 is a schematic diagram showing a liquid circulation path according to an embodiment of the present invention. [Figure 4] 1 is a perspective view showing a liquid ejection head according to an embodiment of the present invention. [Diagram 5] FIG. 2 is an exploded perspective view of the liquid ejection head according to the embodiment of the present invention. [Figure 6] FIG. 2 is a plan view of the flow path member according to the embodiment of the present invention. [Figure 7] 2A and 2B are perspective and cross-sectional views of a flow path member and a discharge module according to an embodiment of the present invention. [Figure 8] 1A and 1B are a perspective view and an exploded perspective view of a dispensing module according to an embodiment of the present invention; [Figure 9] FIG. 2 is a plan view of an element substrate according to the embodiment of the present invention. [Figure 10] 2 is a cross-sectional view of an element substrate according to an embodiment of the present invention. [Figure 11] 2A and 2B are a plan view and a cross-sectional view showing the inside of a liquid ejection head according to an embodiment of the present invention. [Figure 12] FIG. 2 is an enlarged plan view of the vicinity of an ejection port of a liquid ejection head according to an embodiment of the present invention. [Figure 13] 4 is a partial enlarged plan view of an adjacent portion of an element substrate according to the embodiment of the present invention. FIG. [Figure 14] 1A and 1B are a plan view of an element substrate and a cross-sectional view of a discharge module in a conventional example. [Figure 15] 2A and 2B are a plan view of an element substrate and a cross-sectional view of a discharge module in the first embodiment. [Figure 16] 13A and 13B are a plan view of an element substrate and a cross-sectional view of a discharge module according to a second embodiment. [Figure 17] 13A and 13B are a plan view of an element substrate and a cross-sectional view of a discharge module according to a third embodiment. [Figure 18] 13A and 13B are a plan view of an element substrate and a cross-sectional view of a discharge module according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the following description does not limit the scope of the present invention. As an example, in this embodiment, a thermal method is adopted in which a heat generating element generates bubbles to eject liquid. However, the present invention can also be applied to a liquid ejection head that employs a piezo method using a piezoelectric element as an energy generating element for ejecting liquid, or other various liquid ejection methods. The liquid ejection head of the present invention and a liquid ejection device equipped with the liquid ejection head can be applied to devices such as inkjet printers, copiers, facsimiles with communication systems, and word processors with printer units. Furthermore, they can be applied to industrial recording devices that are combined in a composite manner with various processing devices. For example, they can also be used for applications such as biochip production, electronic circuit printing, and semiconductor substrate production.

[0011] Although the present embodiment is a liquid ejection device in a form in which liquid such as ink is circulated between a tank and a liquid ejection head, other forms may be used. For example, the liquid may not be circulated, but may be provided on the upstream side and downstream side of the liquid ejection head, and the liquid may be caused to flow in the pressure chamber by flowing from one tank to the other tank. In addition, the present embodiment is a so-called line type (page wide type) head having a length corresponding to the width of the recording medium, but the present invention can also be applied to a so-called serial type liquid ejection head that performs printing while scanning the recording medium. An example of a serial type liquid ejection head is a configuration in which one element substrate for black ink and one element substrate for color ink are mounted, but the present invention is not limited to this. A short line head shorter than the width of the recording medium may be created by arranging several element substrates so that the ejection ports overlap in the ejection port row direction, and the recording medium may be scanned with the line head.

[0012] (First embodiment) <Overall configuration of the device> 1 is a diagram showing an example of a liquid ejection device in this embodiment. The liquid ejection device in this embodiment is a liquid ejection device 1000 (hereinafter, simply referred to as device 1000) that serves as an inkjet printer that records a color image on a recording medium 2 by ejecting yellow (Y), magenta (M), cyan (C), and black (Bk) inks. In the figure, the X direction is the transport direction of the recording medium 2, the Y direction is the width direction of the recording medium, and the Z direction is the direction intersecting the X and Y directions and is the direction in which liquid is ejected.

[0013] Fig. 1 shows an apparatus 1000 in which a liquid ejection head 3 applies ink directly to a recording medium 2 transported in the X direction. The recording medium 2 is mounted on a transport section 1, and is transported in the X direction at a predetermined speed below four liquid ejection heads 3 (3Y, 3M, 3C, 3Bk) that eject different inks. In Fig. 1, the four liquid ejection heads 3 are arranged in the X direction in the order of 3Bk, 3C, 3M, 3Y, and inks are applied to the recording medium 2 in the order of black, cyan, magenta, and yellow. Each liquid ejection head 3 has a plurality of ejection openings arranged in the Y direction for ejecting ink.

[0014] 1 shows cut paper as the recording medium 2, the recording medium 2 may be continuous paper supplied from a roll of paper. Also, the recording medium is not limited to paper, and may be, for example, film.

[0015] In the present embodiment, the liquid ejection device has been described as having a configuration in which one liquid ejection head ejects ink of a single color, but one liquid ejection head may be configured to eject ink of multiple colors, or may be configured to eject liquid other than ink, such as a reaction liquid or an overcoat agent.

[0016] 2 is a block diagram for explaining the control configuration of the liquid ejection device 1000. The control unit 500 is composed of a CPU and the like, and controls the entire liquid ejection device 1000 while using a RAM 502 as a work area in accordance with programs and various parameters stored in a ROM 501. The control unit 500 performs predetermined image processing on image data received from an externally connected host device 600 in accordance with the programs and parameters stored in the ROM 501, and generates ejection data that can be ejected by the liquid ejection head 3. Then, the liquid ejection head 3 is driven in accordance with this ejection data, causing it to eject ink at a predetermined frequency.

[0017] During the ejection operation by the liquid ejection head 3, the control unit 500 drives the transport motor 503 to transport the recording medium 2 in the X direction at a speed corresponding to the drive frequency. As a result, an image is recorded on the recording medium 2 according to the image data received from the host device 600. Information on the use areas of the ejection ports used for ejection in the liquid ejection head 3 is stored in the ROM 501 in a rewritable manner for each liquid ejection head 3.

[0018] <Liquid circulation path> 3 is a schematic diagram showing the circulation paths of liquid in the liquid ejection device of this embodiment, and shows the liquid ejection head 3 fluidly connected to a first circulation pump 1002, a buffer tank 1003, etc. Note that, although Fig. 3 only shows the path through which ink flows in the liquid ejection head corresponding to one color of ink, the device main body 1000 is provided with circulation paths corresponding to the type of liquid, such as ink, to be ejected.

[0019] The buffer tank 1003, which serves as a sub-tank and is connected to the main tank 1006, has an air communication port (not shown) that communicates between the inside of the tank and the outside, and is capable of discharging air bubbles in the ink to the outside. The buffer tank 1003 is also connected to a refill pump 1005. When liquid is consumed in the liquid discharge head 3 by discharging (discharging) ink from the discharge ports of the liquid discharge head for recording by discharging ink or for suction recovery, the refill pump 1005 transfers the amount of consumed ink from the main tank 1006 to the buffer tank 1003.

[0020] The first circulation pump 1002 has a role of drawing liquid from the liquid connection portion 111 of the liquid ejection head 3 and flowing it to the buffer tank 1003. When the liquid ejection head 3 is driven, a constant amount of ink flows inside the common recovery channel 212 by the first circulation pump 1002.

[0021] The negative pressure control unit 230 is provided between the second circulation pump 1004 and the liquid ejection unit 300. Even if the flow rate of the circulation system varies due to a difference in the duty of recording, the negative pressure control unit 230 has a function of operating to maintain the pressure downstream (the liquid ejection unit 300 side) at a preset constant pressure.

[0022] As shown in Fig. 3, the negative pressure control unit 230 includes two pressure adjustment mechanisms, and different control pressures are set for each pressure adjustment mechanism. Of the two pressure adjustment mechanisms, the relatively high pressure setting side (negative pressure control section 230H, indicated as H in Fig. 3) and the relatively low pressure side (negative pressure control section 230L, indicated as L in Fig. 3) are connected to the common supply flow path 211 and the common recovery flow path 212 in the liquid ejection unit 300 via the liquid supply unit 220. The liquid ejection unit 300 is provided with the common supply flow path 211, the common recovery flow path 212, and individual supply flow paths 213a and individual recovery flow paths 213b that communicate with each element substrate having an ejection port. Details of the element substrate 10 will be described later. Since the individual flow paths 213 communicate with the common supply flow path 211 and the common recovery flow path 212, a part of the liquid flowed by the second circulation pump 1004 flows from the common supply flow path 211 through the internal flow paths of the element substrate 10 to the common recovery flow path 212 (arrow in FIG. 3). This is because a pressure difference is provided between the pressure adjustment mechanism H connected to the common supply flow path 211 and the pressure adjustment mechanism L connected to the common recovery flow path 212, and the first circulation pump 1002 is connected only to the common recovery flow path 212.

[0023] In this way, in the liquid ejection unit 300, a liquid flow that passes through the common recovery flow path 212 and a flow that passes through each element substrate 10 from the common supply flow path 211 to the common recovery flow path 212 are generated. Therefore, heat generated in each element substrate 10 can be discharged to the outside of the element substrate 10 by the flow from the common supply flow path 211 to the common recovery flow path 212. Furthermore, with this configuration, when recording is being performed by the liquid ejection head 3, an ink flow can be generated even in ejection ports and pressure chambers that are not performing recording, so that thickening of the ink in those areas can be suppressed. Also, thickened ink and foreign matter in the ink can be discharged to the common recovery flow path 212. Therefore, the liquid ejection head 3 of this embodiment is capable of high-speed, high-quality recording.

[0024] <Configuration of Liquid Ejection Head> 4(a) and 4(b) are perspective views of the liquid ejection head 3 according to the present embodiment. The liquid ejection head 3 is a line-type liquid ejection head in which 17 element substrates 10 capable of ejecting ink are arranged in a straight line (arranged in-line). As shown in FIG. 4(a) and FIG. 4(b), the liquid ejection head 3 includes each element substrate 10, a signal input terminal 91 and a power supply terminal 92 electrically connected via an electric wiring board (flexible wiring board) 40 and an electric wiring board 90. The signal input terminal 91 and the power supply terminal 92 are electrically connected to a control unit of the device 1000, and supply the ejection drive signal and the power required for ejection to the element substrate 10, respectively. By consolidating the wiring by the electric circuit in the electric wiring board 90, the number of signal output terminals 91 and the power supply terminals 92 can be made smaller than the number of element substrates 10. This reduces the number of electrical connections that need to be removed when assembling the liquid ejection head 3 to the device 1000 or when replacing the liquid ejection head 3. 4(a), liquid connection part 111 provided on one side of liquid ejection head 3 is connected to a liquid supply system of device 1000. This allows ink to be supplied from the supply system of device 1000 to liquid ejection head 3, and ink that has passed through liquid ejection head 3 is collected into the supply system of device 1000. In this way, ink can be circulated via the path of device 1000 and the path of liquid ejection head 3.

[0025] FIG. 5 shows an exploded perspective view of each part or unit constituting the liquid ejection head 3. The liquid ejection unit 300, the liquid supply unit 220, and the electric wiring board 90 are attached to the housing 80. The liquid supply unit 220 is provided with a liquid connection part 111, and the liquid supply unit 220 is provided with a filter 221 (FIG. 3) communicating with each opening of the liquid connection part 111 in order to remove foreign matter from the ink being supplied. The liquid that has passed through the filter 221 is supplied to the negative pressure control unit 230 arranged on the liquid supply unit 220. The negative pressure control unit 230 is a unit consisting of a pressure adjustment valve, and the valves and spring members provided therein greatly attenuate the pressure loss change in the supply system of the device 1000 (the supply system upstream of the liquid ejection head 3) that occurs with the fluctuation of the liquid flow rate. This makes it possible to stabilize the negative pressure change downstream of the negative pressure control unit 230 (the liquid ejection unit 300 side) within a certain range. The negative pressure control unit 230 has two pressure regulating valves built in, each set to a different control pressure, with the high pressure side connected to the common supply flow path 211 in the liquid ejection unit 300 and the low pressure side connected to the common recovery flow path 212 via the liquid supply unit 220.

[0026] The housing 80 has a liquid discharge unit support part 81 and an electric wiring board support part 82, and supports the liquid discharge unit 300 and the electric wiring board 90 while ensuring the rigidity of the liquid discharge head 3. The electric wiring board support part 82 is for supporting the electric wiring board 90, and is fixed to the liquid discharge unit support part 81 by screwing. The liquid discharge unit support part 81 is provided with openings 83 and 84 into which a joint rubber 100 is inserted. The liquid supplied from the liquid supply unit 220 is guided via the joint rubber 100 to the second flow path member 60 constituting the liquid discharge unit 300.

[0027] Next, the configuration of the flow path member 210 included in the liquid discharge unit 300 will be described. As shown in FIG. 5, in the flow path member 210, a first flow path member 50 and a second flow path member 60 are laminated. A plurality of discharge modules 200 are bonded to the bonding surface of the first flow path member 50 with an adhesive (not shown). The flow path member 210 is a flow path member for distributing liquid supplied from the liquid supply unit 220 to each discharge module 200 and returning liquid flowing out from the discharge module 200 to the liquid supply unit 220. In addition, the flow path member 210 is fixed to the liquid discharge unit support part 81 by screws, which suppresses warping and deformation of the flow path member 210.

[0028] FIG. 6 is a diagram for explaining a detailed configuration of the flow path member 210. FIG. 6(a) shows the support member 30 provided on the surface of the first flow path member 50 on which the discharge module 200 is mounted, and FIG. 6(b) shows the contact surface of the first flow path member 50 with the support member 30. FIG. 6(c) shows a cross-sectional view of the first flow path member 50 on a surface perpendicular to the Z direction and near the center in the Z direction, and FIG. 6(d) shows the surface of the second flow path member 60 on the side that contacts the liquid discharge unit support part 81. Note that FIGS. 6(a) to 6(c) are views seen from the discharge module 200 side, and FIG. 6(d) is a view seen from the liquid discharge unit support part 81 side.

[0029] A plurality of support members 30 arranged in the Y direction are disposed on the surface of the first flow path member 50 opposite to the second flow path member 60, and one element substrate 10 is disposed on each support member 30. By adjusting the number of arranged discharge modules 200, it is possible to configure liquid discharge heads 3 of various sizes.

[0030] 6(a), the support member 30 has a communication port 31 on the surface that abuts against the element substrate 10, the communication port 31 being fluidly connected to the element substrate 10 and serving as the individual supply flow passages 213a and the individual recovery flow passages 213b described above in FIG. 3. As shown in FIG. 6(b), the communication port 31 is fluidly connected to the common supply flow passage 211 or the common recovery flow passage 212 via a communication port 51 provided in the flow passage member 50.

[0031] 6(c), in a middle layer near the center in the Z direction of the first flow path member 50, common flow path grooves 61 and 62 which become the common supply flow path 211 and the common recovery flow path 212 described in FIGS. 3(a) and 3(b) extend in the Y direction. As shown in FIG. 6(d), at both ends or one end of the common flow path grooves 61 and 62, a common communication port 63 which is fluidly connected to the liquid supply unit 220 is formed.

[0032] Figures 7(a) and (b) are a perspective view and a cross-sectional view for explaining a flow path structure formed inside the liquid discharge unit 300. Figure 7(a) is an enlarged perspective view of the flow path member 210 as viewed from the Z direction, and Figure 7(b) is a cross-sectional view taken along line VIIb-VIIb in Figure 7(a).

[0033] The element substrate 10 of the ejection module 200 is placed on the communication port 51 of the first flow path member 50 via the support member 30. In FIG. 7(b), only the communication port 51 corresponding to the common supply flow path 211 is illustrated, but in another cross section, the common recovery flow path 212 and the communication port 51 are communicated with each other as shown in FIG. 6. In the support member 30 and the element substrate 10 included in each ejection module 200, a flow path is formed for supplying ink from the first flow path member 50 to the heating resistor element 15 (see FIG. 9) provided on the element substrate 10. In addition, in the support member 30 and the element substrate 10, a flow path is formed for recovering (circulating) a part or all of the liquid supplied to the heating resistor element 15 to the first flow path member 50.

[0034] As described above, the common supply flow path 211 is connected to the negative pressure control unit 230H of a relatively high pressure, and the common recovery flow path 212 is connected to the negative pressure control unit 230L of a relatively low pressure. An ink supply path is formed that supplies ink to a flow path formed in the element substrate 10 through the common communication port 63 (see FIG. 6), the common supply flow path 211, and the communication port 31. Similarly, an ink recovery path is formed from the flow path in the element substrate 10, having the communication port 31, the communication port 51, the common recovery flow path 212, and the common communication port 63 (see FIG. 6(d)). While the ink is circulated in this manner, an ejection operation according to the ejection data is performed in the element substrate 10, and the ink that is not consumed by the ejection operation among the ink supplied through the ink supply path is recovered by the ink recovery path.

[0035] <Configuration of the discharge module> FIG. 8(a) is a perspective view showing one discharge module 200, and FIG. 8(b) is an exploded view thereof. In the manufacturing method of the discharge module 200, first, the element substrate 10 and the flexible wiring substrate 40 are bonded onto the support member 30 in which the communication opening 31 is provided in advance. Then, the electrode pad 16 on the element substrate 10 and the terminal 41 on the flexible wiring substrate 40 are electrically connected by wire bonding, and then the wire bonding portion (electrical connection portion) is covered and sealed with the sealing material 110. As the flexible wiring substrate 40, for example, a substrate in which copper foil is bonded onto a polyimide tape by an adhesive and patterned to make the copper foil into wiring, and electrically connected to the electrode pad 16 of the element substrate 10, can be mentioned. The terminal 42 on the opposite side of the flexible wiring substrate 40 from the element substrate 10 is electrically connected to the connection terminal 93 (see FIG. 5) of the electrical wiring substrate 90. The support member 30 is a support body for supporting the element substrate 10 and a flow path member for fluidly connecting the element substrate 10 and the flow path member 210, and therefore preferably has a high degree of flatness and can be bonded to the element substrate with sufficiently high reliability. As a material for the support member 30, for example, alumina or a resin material is preferable. Sealing of the electrical connection portion will be described in detail later.

[0036] <Configuration of element substrate> The configuration of the element substrate 10 in this embodiment will be described. Fig. 9(a) shows a plan view of the surface of the element substrate 10 on which the ejection ports 13 are formed, Fig. 9(b) shows an enlarged view of a portion indicated by A in Fig. 9(a), and Fig. 9(c) shows a plan view of the back surface of Fig. 9(a). Fig. 10 is a cross-sectional perspective view of the element substrate 10 taken along line XX in Fig. 9(a). Hereinafter, the direction in which an ejection port array in which a plurality of ejection ports 13 are arranged extends is referred to as the "ejection port array direction".

[0037] As shown in FIG. 9(b), a heating resistor element 15, which is a heating element (pressure generating element) for foaming the liquid by utilizing the thermal energy generated by the liquid, is disposed at a position corresponding to each ejection port 13. A pressure chamber 23 having the heating resistor element 15 therein is partitioned by a partition wall 22 formed of a first layer 121 (described later) of the flow path forming member 12. The heating resistor element 15 is electrically connected to the electrode pad 16 by an electric wiring (not shown) provided on the element substrate 10. The heating resistor element 15 generates heat based on a pulse signal input from a control circuit of the liquid ejection device 1000 via an electric wiring substrate 90 (see FIG. 5) and a flexible wiring substrate 40 (see FIG. 8) to boil the liquid. The liquid is ejected from the ejection port 13 by the force of foaming caused by the boiling. As shown in FIG. 9(b), a liquid supply path 18 extends on one side along each ejection port row, and a liquid recovery path 19 extends on the other side along each ejection port row. The liquid supply path 18 and the liquid recovery path 19 are flow paths extending in the ejection port array direction provided in the element substrate 10, and communicate with the ejection ports 13 via the supply ports 17a and the recovery ports 17b, respectively. Figures 9(a) to 9(c) show an element substrate 10 having 16 ejection port arrays as an example.

[0038] As shown in FIG. 9(c) and FIG. 10, a sheet-like cover plate 20 is laminated on the back surface of the element substrate 10, opposite to the surface on which the ejection ports 13 are formed. As shown in FIG. 9(c), the cover plate 20 is provided with a plurality of openings 21 communicating with the liquid supply passage 18 and the liquid recovery passage 19, which will be described later. In this embodiment, the cover plate 20 is provided with four supply openings 21a for one liquid supply passage 18 and three recovery openings 21b for one liquid recovery passage 19, but the number of openings is not limited to this. As shown in FIG. 9(b), each opening 21 in the cover plate 20 communicates with the communication port 51 shown in FIG. 7(a). The cover plate 20 is preferably made of a material having sufficient corrosion resistance against liquid, and high accuracy is required for the opening shape and opening position of the opening 21 so that ink is supplied to the pressure chamber. For this reason, it is preferable to use a photosensitive resin material or a silicon plate as the material of the cover plate 20, and provide the openings 21 by photolithography technology. In this manner, the cover plate 20 changes the pitch of the flow paths by the openings 21, and from the viewpoints of pressure loss, strength and workability, the cover plate is desirably made of a film-like material having a thickness of about 30 to 600 μm.

[0039] Next, the flow of liquid in the element substrate 10 will be described. The element substrate 10 is formed by stacking a substrate 11 made of silicon and a flow path forming member (discharge port forming member) 12 made of a photosensitive resin. In this embodiment, the flow path forming member 12 has a first layer 121 (middle layer) for forming a pressure chamber 23 and a second layer 122 (upper layer) having a discharge port 13. The first layer 121 and the second layer 122 are stacked (laminated) in this order on the surface (first surface 11a) of the substrate 11, and are patterned by being exposed to the optimum photosensitive wavelengths of each layer, and then developed to form the flow path forming member 12. In addition to the above-mentioned method of stacking the first layer and the second layer, any method such as a method of forming a pressure chamber and a discharge port using a mold material can be used as a manufacturing method for the flow path forming member 12. A cover plate 20 is bonded to the back surface of the substrate 11. The cover plate 20 functions as a lid that forms part of the walls of the liquid supply path 18 and the liquid recovery path 19 formed in the substrate 11 of the element substrate 10. In the element substrate 10, the heating resistor element 15 is formed on one surface side of the substrate 11 (see FIG. 9), and grooves that form the liquid supply path 18 and the liquid recovery path 19 extending along the ejection port row are formed on the back surface side. The liquid supply path 18 and the liquid recovery path 19 formed by the substrate 11 and the cover plate 20 are respectively connected to a common supply flow path 211 and a common recovery flow path 212 in the flow path member 210 (see FIG. 7), and a pressure difference is generated between the liquid supply path 18 and the liquid recovery path 19. This pressure difference generates a circulation flow C in which the liquid in the liquid supply path 18 provided in the substrate 11 flows to the liquid recovery path 19 via the supply port 17a, the pressure chamber 23, and the recovery port 17b (flow indicated by the arrow C in FIG. 10). This flow allows the thickened ink, bubbles, foreign matter, and the like that are generated by evaporation from the ejection ports 13 in the ejection ports 13 and pressure chambers 23 that are not performing an ejection operation to be collected into the liquid recovery path 19. It also makes it possible to prevent the ink in the ejection ports 13 and pressure chambers 23 from becoming thicker or the concentration of the coloring material from increasing.As shown in Figure 7, the liquid recovered to the liquid recovery path 19 is recovered in the order of the opening 21 in the cover plate 20 and the communication port 31 in the support member 30, the communication port 31 in the support member 30, the communication port 51 in the first flow path member 50, and the common recovery flow path 212, and is then recovered to the supply path of the liquid ejection device 1000.

[0040] That is, the liquid supplied from the liquid discharge device main body to the liquid discharge head 3 flows, is supplied, and is recovered in the following order. The liquid first flows into the inside of the liquid discharge head 3 from the liquid connection portion 111 of the liquid supply unit 220. Then, the liquid is supplied in this order to the joint rubber 100, the common communication port 63 provided in the second flow path member, the common flow path groove 61 and the communication port 51 provided in the first flow path member. After that, the liquid is supplied to the pressure chamber 23 via the communication port 31 provided in the support member 30, the opening 21 provided in the cover plate 20, the liquid supply path 18 and the supply port 17a provided in the substrate 11. Of the liquid supplied to the pressure chamber 23, the liquid that is not discharged from the discharge port 13 flows in this order through the recovery port 17b and the liquid recovery path 19 provided in the substrate 11, the opening 21 provided in the cover plate 20, and the communication port 31 provided in the support member 30. Thereafter, the liquid flows in sequence through the communication port 51 and the common flow path 62 provided in the first flow path member, the common communication port 63 provided in the second flow path member, and the joint rubber 100. Then, the liquid flows from the liquid connection part 111 provided in the liquid supply unit to the outside of the liquid ejection head 3. In the form of the circulation path shown in FIG. 3, the liquid that flows in from the liquid connection part 111 is supplied to the joint rubber 100 after passing through the negative pressure control unit 230.

[0041] The liquid ejection head of this embodiment further includes a temperature adjustment mechanism (not shown) on the element substrate 10. The element substrate 10 is divided into a plurality of areas for temperature adjustment, and a temperature sensor and a sub-heater that can be controlled individually are provided for each area. The control unit 500 (see FIG. 2) adjusts the temperature based on the temperature (target temperature) set for each area using these temperature sensors and sub-heaters. That is, the control unit 500 drives the sub-heater only in the area where the temperature detected by the temperature sensor is equal to or lower than the target temperature. By setting the target temperature of the element substrate 10 to a relatively high temperature, the viscosity of the ink can be reduced, and ejection and circulation can be performed favorably. By performing such temperature control, the temperature variation within the element substrate 10 and the temperature variation among the plurality of element substrates 10 are suppressed within a predetermined range. This reduces the variation in the ejection amount caused by the temperature variation, and suppresses uneven density in the recorded image. It is preferable that the target temperature of the element substrate 10 is set to a temperature equal to or higher than the equilibrium temperature of the element substrate 10 when all the heating resistor elements 15 are driven at the highest driving frequency assumed. As the temperature sensor, a diode sensor, an aluminum sensor, etc. can be used. Also, as the heating means for the element substrate 10, the heating resistor element 15, which is a heating element, can be used. Specifically, the element substrate 10 can be heated by applying a voltage to the heating resistor element 15 that is not enough to cause bubbles. For example, the heating resistor element 15 can be used as the heating means instead of a sub-heater, or the sub-heater and the heating resistor element 15 can be used together.

[0042] <Liquid flow near the pressure chamber> 11(a) and 11(b) show the inside of the liquid ejection head, where FIG. 11(a) is a plan view (perspective view) showing the heating resistor element and the flow path, and FIG. 11(b) is a cross-sectional view taken along line XIb-XIb in FIG. 11(a). Between the substrate 11 and the flow path forming member 12 of the element substrate 10, a plurality of pressure chambers 23 each having an ejection port 13, and an inlet flow path 24a and an outlet flow path 24b communicating with each pressure chamber 23 are provided. The pressure chambers 23 are partitioned by a wall portion 120 of the flow path forming member 12. The substrate 11 is configured to form a circulation flow C (see FIG. 10) in which the liquid in the liquid supply path 18 flows to the liquid recovery path 19 via the supply port 17a, the inlet flow path 24a, the pressure chamber 23, the outlet flow path 24b, and the recovery port 17b. The speed of the circulating flow C in the pressure chamber is preferably, for example, 1.0 mm / s or more and 250 mm / s or less, which is a speed that has little effect on landing accuracy, etc., even if the discharge operation is performed in a state where the liquid is flowing. As shown in Fig. 11(b), the discharge port 13 is an opening located at the end of a cylindrical discharge port portion 25 formed in the flow path forming member 12, and the discharge port portion 25 connects the discharge port 13 to the pressure chamber 23. The direction in which the liquid is discharged from the discharge port 13 (the up-down direction in Fig. 11(b)) is referred to as the "discharge direction", and the flow direction of the liquid in the pressure chamber 23 (the left-right direction in Fig. 11(b)) is simply referred to as the "flow direction".

[0043] The plurality of supply ports 17a form a supply port row, and the plurality of recovery ports 17b form a recovery port row. An ejection port row in which a plurality of ejection ports 13 are arranged is formed between the supply port row and the recovery port row. In this embodiment, as described above, a pressure difference is provided between the liquid supply path 18 and the liquid recovery path 19. Due to this pressure difference, ink is introduced from the supply port 17a through the inlet flow path 24a into the pressure chamber 23, and a circulating flow C is generated in which ink flows from the outlet flow path 24b to the recovery port 17b.

[0044] A heating resistor element 15 is provided on the bottom surface of the pressure chamber 23 facing the ejection port 13. The ejection port portion (nozzle) 25 penetrates the flow path forming member 12 at a position facing the pressure chamber 23. The outer end of the ejection port portion 25, i.e., the end opposite the heating resistor element 15, forms the ejection port 13 from which ink is ejected. The ejection port portion 25 or the ejection port 13 is provided at a position facing the heating resistor element 15. In this specification, the ejection port 13 is an opening located on the outer surface of the flow path forming member 12 facing the recording medium 2, and the ejection port portion 25 is a portion that communicates between the ejection port 13 and the pressure chamber 23 and means a through hole that penetrates the flow path forming member 12.

[0045] 11, this embodiment does not have a filter such as a columnar structure that is often provided in the flow path of a liquid ejection head to prevent foreign matter such as dust from entering the pressure chamber 23. This is preferable because it is possible to reduce the flow resistance in the flow path and improve the refill performance of the ink, thereby obtaining effects such as increasing the ejection frequency. In the present invention, as described later, foreign matter can be trapped by the flow path (inlet flow path 24a) in the flow path forming member, which has a relatively low height, so that a filter can be eliminated.

[0046] <Outlet shape> FIG. 12(a) is a plan view showing the shape of the discharge port 13 in this embodiment, and FIG. 12(b) is a plan view showing another example of the shape of the discharge port. As shown in FIG. 12(a), in this embodiment, two protrusions 27 are provided on both sides of the straight line L passing through the center F of the discharge port 13, with the same shape, so as to protrude toward the center F. This provides the effect of shortening the tail of the discharged droplet. To be more specific, the meniscus of the ink formed between the protrusions 27 is more easily maintained than the meniscus in other parts. For this reason, the tail of the droplet extending from the discharge port 13 can be cut off at an earlier timing, and the generation of mist, which is a minute droplet generated accompanying the main droplet, can be suppressed. Note that in FIGS. 1 to 11, the discharge port 13 may be depicted without the protrusions 27. If the interval 28 between the protrusions 27 is wide, the tail of the discharged droplets becomes longer and small satellites are more likely to occur, so the interval 28 is desirably 7.0 μm or less, and more desirably 5.0 μm or less. On the other hand, if the interval is too narrow, it may be difficult to form the protrusions or the discharged droplets may be separated into two, so the interval 28 is desirably 2.0 μm or more. In other words, the interval 28 is desirably 2.0 μm or more and 7.0 μm or less, and more desirably 2.0 μm or more and 5.0 μm or less. In this embodiment, the interval 28 is set to 3.0 μm as an example.

[0047] Also, if the tip (center F side) of the protrusion 27 is thick, the discharged droplet may be divided by the protrusion 27 and split into two droplets. Therefore, the width 271 of the tip of the protrusion 27 is preferably 4.0 μm or less, and in this embodiment, it is set to 2.0 μm as an example. When the tip of the protrusion is rounded as in this embodiment shown in FIG. 12(a), the length of the line segment divided by the intersection point between the line L at the tip of the protrusion and two lines extending from the two long sides of the protrusion, as shown by the dotted line in the figure, can be considered as the width 271 of the tip. In addition, in order to increase the strength of the protrusion 27, it is preferable that the width 272 of the base of the protrusion 27 is formed thicker than the tip 271, and in this embodiment, it is set to 4.0 μm as an example. In addition, when the shape of the outlet 13 at the base is curved as in this embodiment shown in Fig. 12(a), the length of the line segment connecting the two intersections of the outer periphery when the outlet 13 is a circle and two lines extending from the two long sides of the protrusion, as shown by the dotted line in the figure, can be considered as the width 272 of the base. Thus, from the viewpoint of droplet formation, the protrusion 27 is preferably shaped so that its width narrows from the base to the tip, and the protrusion may have an arc shape as shown in Fig. 12(b).

[0048] Moreover, it is desirable that the two protrusions 27 extend in a direction substantially parallel to the transport direction (X direction) of the recording medium 2. Since the protrusions 27 have a great influence on the ejection of droplets, when slight variations in the shape of the two protrusions occur in manufacturing, the droplets fly in a direction shifted toward one of the protrusions, resulting in a landing position shift. In general, the landing position shift in the ejection port arrangement direction (Y direction) is easier to see on an image than the landing position shift in the transport direction (X direction) of the recording medium. Therefore, by making the direction of the protrusions substantially parallel to the transport direction of the recording medium 2, the deviation in the ejection port arrangement direction can be suppressed, and an effect of maintaining good printing can be obtained. It is also desirable that the protrusions 27 extend along the flow direction of the liquid in the vicinity of the pressure chamber. In other words, it is desirable that the straight line L on which the protrusions are located forms an angle of 45 degrees or less with respect to the flow path axis connecting the liquid supply path 18 and the liquid recovery path 19, or connecting the inlet flow path 24a and the outlet flow path 24b.

[0049] In this embodiment, two protrusions 27 extend toward the center F of the ejection port, but droplet formation is maintained well even if there is only one protrusion 27. In this case, however, the landing position may be significantly shifted in a direction where there is no protrusion 27, reducing the stability of the landing position, so it is more preferable that two protrusions 27 extend toward the ejection port center F. Also, the present invention can be suitably used even in liquid ejection heads whose ejection ports do not have protrusions 27.

[0050] Furthermore, in order to aim to achieve good image quality with stable ejection quality, it is desirable that the landing dot size of the droplets on the recording medium 2 is relatively small and highly precise. Therefore, in the liquid ejection head of this embodiment, the ejection volume is set to be relatively small at 2.0 ng.

[0051] <Positional relationship between element substrates> FIG. 13 is a partially enlarged plan view showing adjacent portions of element substrates in two adjacent ejection modules. As shown in FIG. 9, in this embodiment, an element substrate 10 having an outer shape of a substantially parallelogram is used. As shown in FIG. 13, each ejection port row (14a to 14d) in which the ejection ports 13 in each element substrate 10 are arranged so as to be inclined at a certain angle with respect to the transport direction of the recording medium 2. As a result, the ejection ports in the adjacent portions of the element substrates 10 overlap at least one ejection port 13 in the transport direction of the recording medium 2. In FIG. 13, two ejection ports on line D overlap each other. With this arrangement, even if the position of the element substrate 10 is slightly deviated from the predetermined position, black stripes and white spots in the recorded image can be made less noticeable by driving control of the overlapping ejection ports. That is, even when a plurality of element substrates 10 are arranged in a straight line (in-line) rather than in a staggered arrangement in order to suppress an increase in the length of the liquid ejection head 3 in the transport direction of the recording medium 2, it is possible to take measures against black streaks and white spots at the joints between the element substrates 10 by using the configuration in Fig. 13. Note that, although the main plane of the element substrate 10 in this embodiment is a parallelogram, the present invention is not limited to this, and the configuration of the present invention can be preferably applied even when an element substrate having a rectangular, trapezoidal, or other shape is used.

[0052] <Configuration to prevent sealing material from flowing> The problem of the present invention will be described below while explaining the sealing of the electrical connection part 70 in the discharge module 200 in more detail. As described above, the electrical connection part (wire bonding part) between the element substrate and the electrical wiring substrate is covered with the sealant 110. If the sealant flows when the sealant is applied, the wires are incompletely covered. In view of this, there is a liquid discharge head having a structure 701 that acts as a wall for preventing the sealant 110 from flowing out of the substrate 11, using an adhesion layer for enhancing adhesion between the substrate 11 and the flow path forming member 12 (or the first layer 121). FIG. 14 shows a plan view of the element substrate 10 of the conventional example. In FIG. 14, the structure 701 formed of the same material as the adhesion layer 700 is provided between the electrode pad row 161 in which the electrode pads 16 are arranged along one side of the substrate 11 and the side of the substrate 11 when the element substrate is viewed in plan. However, since the adhesion layer 700 is generally thin, at 1 to 2 μm, there is a possibility that the sealant 110 may overcome the structure 701 and flow out of the substrate. Therefore, in the present invention, a wall for preventing the above-mentioned sealant 110 from flowing out of the substrate 11 is formed of the flow path forming member 12.

[0053] 15 is a diagram showing the element substrate 10 in the first embodiment. In this embodiment, a structure 123 is formed between the electrode pad row 161 and one side of the element substrate 10, using the same material as the flow path forming member 12, and serves as a wall for preventing the sealant 110 from flowing from the application position. By forming the structure 123 serving as the flow prevention wall in the same layer as the flow path forming member 12, it is possible to prevent the sealant 110 from flowing by using a wall that is taller than the adhesion layer 700 without increasing the number of manufacturing steps.

[0054] As described above, the adhesive layer 700 is a resin layer provided to improve the adhesion between the flow path forming member 12 and the substrate 10. The adhesive layer preferably contains a resin, and more preferably contains at least one of a polyimide resin or a polyetheramide resin. When the adhesive layer 700 made of resin is provided, the adhesive layer 700 is applied to the substrate 10 in a liquid state, so that the adhesive layer must be applied before the flow path forming member 12 is patterned to form the flow path and the pressure chamber, and this places restrictions on the manufacturing process. When the adhesive layer 700 is good between the flow path forming member 12 and the substrate 10, it is not necessary to provide the adhesive layer 700, and it is preferable that the first layer 121 is disposed in contact with the first surface 11a of the substrate 11. In this case, there is an advantage that there are fewer restrictions on the manufacturing process than when an adhesive layer is provided, and the number of steps can be reduced. In order to improve the adhesiveness of the first layer 121 to the substrate, for example, the first layer 121 can be a resin containing polyethylene glycol. FIG. 15(b) shows a plan view of the element substrate 10 of this embodiment having a configuration without the adhesive layer 700. Figure 15(c) shows a cross-sectional view of the dispensing module 200 corresponding to the position XVc-XVc in Figure 15(b), although the support member 30 is omitted in Figure 15(c).

[0055] The height of the structure 123 in the direction perpendicular to the substrate 10 is preferably 3 μm or more and 25 μm or less. If the height of the structure 123 is too low, the sealant 110 will easily flow, as in the configuration of FIG. 14 in which the structure is provided only with the adhesive layer 700. If the height of the structure 123 is too high, it will be difficult to fill the sealant 110 around the electrical connection portion 70, and it will be difficult to form the electrical connection portion 70. In FIG. 15(c), the structure 123 is composed of only the first layer 121 of the flow path forming member. In this case, the structure 123 is preferably at a height that can easily achieve both prevention of flow of the sealant 110 and ease of forming the electrical connection portion 70.

[0056] Furthermore, the distance L1 between the end of the side of the substrate 11 having the electrode pad row 161 and the structure 123 is preferably 2 μm or more and 200 μm or less. In particular, if the distance between the end of the substrate 11 and the structure 123 is large, the distance between the end of the substrate 11 and the electrode pad row 161 is likely to become large, which may make it difficult to form the electrical connection part 70.

[0057] 15(c), in a direction parallel to the first surface 11a and perpendicular to the direction in which the electrode pad row 161 extends, the distance between the first layer 121 and the electrode pad row 161 is smaller than the distance between the second layer 122 and the electrode pad row 161. That is, in a cross section perpendicular to the electrode pad row 161, the first layer 121 and the second layer 122 are stepped. In this case, the area in which the sealant 110 contacts the first layer 121 increases, and the adhesion of the sealant 110 to the element substrate 10 can be improved. In particular, when the second layer 122 has a water-repellent layer on the surface on the discharge port 13 side, the adhesion between the second layer 122 and the sealant 110 is poor, so that a stepped shape between the first layer 121 and the second layer 122, which increases the contact area between the sealant 110 and the first layer 121, is more preferable. The distance L2 between the end of the first layer 121 on the electrode pad row 161 side and the end of the second layer 122 in a direction parallel to the first surface 11a and perpendicular to the direction in which the electrode pad row 161 extends can be, for example, 1 to 2000 μm.

[0058] In the following embodiment, the differences from the above-mentioned first embodiment will be mainly described, and the description of the same parts as those in the above-mentioned configuration will be omitted.

[0059] Second embodiment 16 is a diagram showing the element substrate 10 in this embodiment, where FIG. 16(a) shows a configuration having an adhesive layer and FIG. 16(b) shows a configuration having no adhesive layer. In the first embodiment shown in FIG. 15, the sealing material may flow to the outside of the element substrate 10 in the arrangement direction of the electrode pads 16. Therefore, in this embodiment, as shown in FIG. 16, structures 123 made of the same material as the first layer 121 are arranged on both sides in the arrangement direction of the electrode pads 16 and between the sides of the element substrate 10 and the electrode pads 16. That is, when the substrate 10 is viewed in a plane, the structures 123 are arranged to surround the electrode pad rows.

[0060] (Third embodiment) 17(a) and (b) are diagrams showing the element substrate 10 in this embodiment, where FIG. 17(a) shows a configuration having an adhesive layer, and FIG. 17(b) shows a configuration having no adhesive layer. Also, FIG. 17(c) shows a cross-sectional view of the discharge module 200 corresponding to the position of XVIIc-XVIIc in FIG. 17(b). In this embodiment, the first layer 121 is formed over substantially the entire first surface 11a of the element substrate 10, and the first layer 121 is removed only around the electrode pad row 161. In other words, when the substrate 11 is viewed in plan, the electrode pad row 161 is located within the opening 124 of the first layer 121. As a result, the area of ​​the substrate 11 covered by the first layer 121 is increased compared to the first and second embodiments, and therefore the protection of the substrate 11 can be improved. In other words, the area of ​​the substrate 11 that is covered only by the sealing material 110 is reduced compared to the first and second embodiments, improving the protection of the substrate 11. Here, the distance L3 between the first layer 121 and the electrode pad row 161 on the side of the region in which the ejection ports are formed in the direction parallel to the first surface 11a is preferably in the range of 2 μm to 200 μm.

[0061] 17, the second layer 122 in which the discharge ports 13 are formed is disposed only in the formation area of ​​the discharge ports 13, and the openings 124 are formed only in the first layer 121. However, a configuration in which the flow path forming member 12 is disposed over substantially the entire first surface 11a of the substrate 11, and the openings 124 are formed in the first layer 121 and the second layer 122 may also be used.

[0062] (Fourth embodiment) 18A and 18B are diagrams showing the element substrate 10 in this embodiment, in which FIG. 18A shows a configuration having an adhesive layer and FIG. 18B shows a configuration having no adhesive layer. In this embodiment, a plurality of openings 124 are formed by removing the first layer 121 corresponding to each electrode pad 16. This increases the area of ​​the substrate 11 covered by the first layer 121 compared to the third embodiment shown in FIG. 17, so that the protection of the substrate 11 can be further improved. In this case, for example, the distance between the first layer 121 and the electrode pad row 161 in the direction parallel to the first surface 11a can be in the range of 2 μm to 20 μm.

[0063] Furthermore, if one element substrate 10 has a plurality of openings 124, a configuration in which a plurality of electrode pads 16 are arranged in one opening 124 may be used. Even in this case, the effect of improving the protection of the substrate can be obtained compared to the configuration in which all the electrode pads 16 are arranged in one opening of the second layer 122, as in the third embodiment.

[0064] 18, the second layer 122 in which the discharge ports 13 are formed is disposed only in the formation area of ​​the discharge ports 13, and the multiple openings 124 are formed only in the first layer 121. However, a configuration in which the flow path forming member 12 is disposed over substantially the entire first surface 11a of the substrate 11, and the openings 124 are formed in the first layer 121 and the second layer 122 may also be used. [Explanation of symbols]

[0065] 3 Liquid ejection head 10 Element substrate 11 Substrate 12 Flow path forming member 16 Electrode Pads 110 Encapsulating material 200 Dispensing Module 40 Electrical wiring board 70 Electrical Connections

Claims

1. On a first surface of the substrate, an element substrate including: an element for ejecting liquid; a flow path forming member having a pressure chamber and an ejection port communicating with the pressure chamber and ejecting the liquid; and a pad row in which a plurality of pads electrically connected to the element are arranged along one side of the substrate; an electric wiring board connected to the pad via an electric connection part; a sealing material disposed on the first surface of the substrate so as to cover the electrical connection portion; The liquid ejection head, in which, when the element substrate is viewed from above, the flow path forming member has an opening, and the pad is positioned within the opening.

2. The flow path forming member is a first layer in contact with the first surface and forming the pressure chamber; a second layer provided on the opposite side of the first layer to the substrate, the second layer having the ejection port; having The liquid ejection head according to claim 1 , wherein the opening is provided in the first layer.

3. 3. The liquid ejection head according to claim 2, wherein the height of the first layer in a direction perpendicular to the substrate is 3 [mu]m or more and 25 [mu]m or less.

4. The liquid ejection head according to claim 1 , wherein the pad row is positioned within the opening.

5. On a first surface of the substrate, an element substrate including: an element for ejecting liquid; a flow path forming member having a pressure chamber and an ejection port communicating with the pressure chamber and ejecting the liquid; and a pad row in which a plurality of pads electrically connected to the element are arranged along one side of the substrate; an electric wiring board connected to the pad via an electric connection part; a sealing material disposed on the first surface of the substrate so as to cover the electrical connection portion; The liquid ejection head has a structure, which is made of the same material as the flow path forming member, between the side and the pad row when viewed from a direction perpendicular to the substrate.

6. 6. The liquid ejection head according to claim 5, wherein the height of the structures in a direction perpendicular to the substrate is 3 [mu]m or more and 25 [mu]m or less.

7. The flow path forming member is a first layer in contact with the first surface and forming the pressure chamber; a second layer provided on the opposite side of the first layer to the substrate, the second layer having the ejection port; having The liquid ejection head according to claim 5 , wherein the structure is made of the same material as the first layer.

8. The liquid ejection head according to claim 5 , wherein the structure is disposed so as to surround the pad when the element substrate is viewed from above.

9. The liquid ejection head according to claim 4 , wherein the structure is disposed so as to surround the pad row when the element substrate is viewed from above.

10. In a direction parallel to the first surface and perpendicular to a direction in which the pad row extends, On the side where the discharge port is formed, 8. The liquid ejection head according to claim 2, wherein a distance between the first layer and the pad row is smaller than a distance between the second layer and the pad row.

11. 8. The liquid ejection head according to claim 2, wherein the distance between the first layer and the pad row in a direction parallel to the first surface and perpendicular to a direction in which the pad row extends is 2 [mu]m or more and 200 [mu]m or less.

12. The liquid ejection head according to claim 1 , wherein the electrical connection portion is a wire.

13. The liquid ejection head according to claim 1 , wherein the flow passage forming member is made of a resin.

14. The liquid ejection head according to claim 2 or 7, wherein the first layer is disposed in contact with the first surface of the substrate.

15. The liquid ejection head according to claim 2 or 7, wherein the first layer is disposed on the first surface of the substrate via an adhesive layer.

16. The liquid ejection head according to claim 2 or 7, wherein the first layer contains polyethylene glycol.

17. On a first surface of the substrate, an element substrate including: an element for ejecting liquid; a flow path forming member having a pressure chamber and an ejection port communicating with the pressure chamber and ejecting the liquid; and a pad row in which a plurality of pads electrically connected to the element are arranged along one side of the substrate; an electric wiring board connected to the pad via an electric connection part; a sealing material disposed on the first surface of the substrate so as to cover the electrical connection portion; A method for manufacturing a liquid ejection head, the flow path forming member having an opening, the pad being positioned within the opening, when the element substrate is viewed from above, comprising: forming a layer that will become the flow path forming member on the first surface of the substrate; and forming the flow path forming member by patterning the layer to simultaneously form the pressure chambers and the openings.

18. The flow path forming member is a first layer in contact with the first surface and forming the pressure chamber; a second layer provided on the opposite side of the first layer to the substrate, the second layer having the ejection port; having A method for manufacturing a liquid ejection head, the method comprising the steps of:

18. A method for manufacturing a liquid ejection head according to claim 17, comprising: a step of forming a layer to become the first layer on the first surface of the substrate; and a step of patterning the layer to become the first layer to simultaneously form the pressure chamber and the opening.

Images