Liquid ejecting head and manufacturing method for liquid ejecting head

Abstract

A liquid ejecting head includes an element substrate, an electrical wiring board, and a sealant. The element substrate includes a substrate having a first surface, and an element, a channel forming member, and a pad array arranged at the first surface of the substrate. The element is configured to eject a liquid. The channel forming member includes a pressure chamber and an ejection port that communicates with the pressure chamber and through which the liquid is ejected. The pad array includes a plurality of pads electrically connected to the elements and arranged along one side of the substrate. The electrical wiring board is connected to each of the pads via an electrical connection portion. The sealant is disposed on the first surface of the substrate and surrounds the electrical connection portion. In the element substrate, the channel forming member has an opening, and the pad array is located within the opening. The present disclosure also relates to a manufacturing method for a liquid ejecting head.

Description

Technical Field

[0001] The present disclosure relates to a liquid ejection head and a manufacturing method for the liquid ejection head. Background Art

[0002] A liquid ejection head assembled to a liquid ejection device such as an inkjet printer includes an element substrate and a nozzle plate. The element substrate includes an element for pressurizing a liquid. The nozzle plate includes an ejection port. When the element is driven, the liquid is pressurized. The pressurized liquid is ejected from the ejection head as droplets through the ejection port. The element substrate including the element is provided with an electrode (e.g., an electrode pad) that is electrically connected to an electrical wiring board to receive power from an external source for driving the element. An electrical connection (e.g., a wire or an internal lead) connecting the electrode and the electrical wiring board is sealed with a sealant (e.g., a resin material) to reduce adhesion of ink. The sealant is applied to the electrical connection, and the applied sealant is cured by heating or other methods to cover the electrical connection.

[0003] However, if the sealant flows from a position on the element substrate to which the sealant has been applied, this may result in a failure to provide sufficient coverage of the electrical connection in some cases. Therefore, some liquid ejection heads include a member on the element substrate that serves as a wall to prevent such flow of the sealant. For example, Japanese Patent Laid-Open No. 2014-000733 discloses a liquid ejection head in which an insulating member is arranged between an electrode pad array on the element substrate and an edge of a substrate corresponding to the electrode pad array. The insulating member disclosed in Japanese Patent Laid-Open No. 2014-000733 is formed simultaneously with the adhesive layer by photolithography from the same material as that of the adhesive layer. The adhesive layer is provided between the element substrate and the nozzle plate to improve adhesion between the element substrate and the nozzle plate.

[0004] In the case of the liquid ejection head disclosed in Japanese Patent Laid-Open No. 2014-000733, a wall for preventing the sealant from flowing to the outside of the element substrate is formed by using an adhesive layer. However, the adhesive layer generally has a small height, which means that an increase in the amount of sealant applied may potentially cause the sealant to overflow over the wall to the outside of the element substrate. Such flow of the sealant may cause bubbles to be trapped in the sealant. During the heat curing of the sealant, the bubbles may expand, which may potentially lead to exposure of the electrical connection portion. Summary of the invention

[0005] The present disclosure provides a liquid ejection head in which a wall for reducing the flow of a sealant is formed on an element substrate by using a channel forming member for defining a channel. Therefore, the liquid ejection head makes it easier to prevent the sealant from flowing from its application position and provides improved electrical reliability.

[0006] The present disclosure provides a liquid ejection head, which includes an element substrate, an electrical wiring board and a sealant. The element substrate includes a substrate, an element, a channel forming member and a pad array. The substrate has a first surface. The element is configured to eject liquid. The channel forming member includes a pressure chamber and an ejection port. The ejection port is a port connected to the pressure chamber, and the liquid is ejected through the ejection port. The pad array includes a plurality of pads, which are electrically connected to the element and arranged along one side of the substrate. The element, the channel forming member and the pad array are arranged at the first surface of the substrate. The electrical wiring board is connected to each of the plurality of pads via an electrical connection portion. The sealant is arranged on the first surface of the substrate and surrounds the electrical connection portion. In a plan view of the element substrate, the channel forming member has an opening, and the pad array is located within the opening.

[0007] Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 A liquid ejection device according to some embodiments of the present disclosure is shown.

[0009] Figure 2 A control system according to some embodiments is conceptually illustrated.

[0010] Figure 3 Schematically illustrated is a liquid circulation path according to some embodiments.

[0011] Figure 4A and Figure 4B is a perspective view of a liquid ejection head according to some embodiments.

[0012] Figure 5 is an exploded perspective view of a liquid ejection head according to some embodiments.

[0013] FIG. 6A to FIG. 6D is a plan view of a channel member according to some embodiments.

[0014] Fig. 7A and Figure 7B 2 are perspective and cross-sectional views, respectively, of a channel member and an injection module according to some embodiments.

[0015] Fig. 8A and Figure 8B 2 are a perspective view and an exploded perspective view, respectively, of a jetting module according to some embodiments.

[0016] 9A to 9C is a plan view of a device substrate according to some embodiments.

[0017] Fig.10 is a perspective cross-sectional view of a device substrate according to some embodiments.

[0018] Fig.11A and Fig. 11B 1 and 2 are respectively a plan view and a cross-sectional view of the interior of a liquid ejection head according to some embodiments.

[0019] Fig. 12A and Fig. 12B is an enlarged plan view of the vicinity of an ejection port of a liquid ejection head according to some embodiments.

[0020] Fig.13 is a partially enlarged plan view of portions of element substrates adjacent to each other according to some embodiments.

[0021] Fig.14A is a plan view of a component substrate according to the prior art.

[0022] Fig. 14B is a cross-sectional view of an injection module according to the prior art.

[0023] Fig.15A and Fig. 15B is a plan view of an element substrate according to the first embodiment.

[0024] Fig. 15C is a cross-sectional view of the injection module according to the first embodiment.

[0025] Fig.16A and Fig. 16B is a plan view of an element substrate according to the second embodiment.

[0026] Fig.17A and Fig. 17B is a plan view of an element substrate according to the third embodiment.

[0027] Fig. 17C is a cross-sectional view of a spray module according to a third embodiment.

[0028] Fig.18A and Fig.18B is a plan view of an element substrate according to a fourth embodiment. DETAILED DESCRIPTION

[0029] Various exemplary embodiments, features and aspects of the present disclosure are described below with reference to the accompanying drawings. However, it should be noted that the following description is not intended to limit the scope of the present disclosure. In one example, the embodiment adopts a thermal method that uses a heating element to generate bubbles to eject liquid. However, the embodiment may also be applied to liquid ejection heads that adopt a piezoelectric method (which uses a piezoelectric element as an energy generating element for ejecting liquid) and various other liquid ejection methods. The liquid ejection head according to the present disclosure and the liquid ejection device according to the present disclosure including the liquid ejection head may be applied to devices such as inkjet printers, copiers, fax machines including communication systems, and word processors including printer units. In addition, the present disclosure may be applied to industrial recording devices that are combined with various processors in a complex manner. Other exemplary applications of the present disclosure may include biochip manufacturing, printing of electronic circuits, and semiconductor substrate manufacturing.

[0030] Although the embodiments relate to a type of liquid ejection device that circulates a liquid such as ink between a tank and a liquid ejection head, the embodiments may relate to other types of liquid ejection devices. For example, the liquid ejection device may be of a type in which the liquid does not circulate, but two tanks are set, one upstream of the liquid ejection head and one downstream of the liquid ejection head, and the liquid is caused to flow from one of the two tanks to the other tank to flow the liquid in the pressure chamber. Although the embodiments relate to a so-called line (page width) head having a length corresponding to the width of the recording medium, the embodiments may also be applied to a so-called serial liquid ejection head, with which recording is performed while the liquid ejection head is scanned on the recording medium. Exemplary configurations of serial liquid ejection heads include, but are not limited to, configurations including one element substrate for black ink and one element substrate for color ink. In an alternative configuration, a short line head shorter than the width of the recording medium may be prepared, and the short line head may be caused to scan on the recording medium. The short line head includes a plurality of element substrates arranged along the direction of the ejection port array in a manner that the ejection port overlaps the element substrate.

[0031] First embodiment

[0032] Overall layout of equipment

[0033] Figure 1 An example of a liquid ejection device according to a first embodiment is shown. The liquid ejection device according to the first embodiment is a liquid ejection device 1000 (hereinafter also simply referred to as "device 1000"), which is used as an inkjet printer that records a color image on a recording medium 2 by ejecting inks of the following colors: yellow (Y), magenta (M), cyan (C), and black (Bk). Figure 1In FIG. 1 , the X direction indicates the conveying direction of the recording medium 2 , the Y direction indicates the width direction of the recording medium, and the Z direction indicates a direction crossing the X direction and the Y direction, and the liquid is ejected along the Z direction.

[0034] Figure 1 A type of apparatus 1000 is shown in which a liquid ejecting head 3 directly applies ink to a recording medium 2 being conveyed in the X direction. The recording medium 2 is mounted on a conveying portion 1 and conveyed at a predetermined speed under four liquid ejecting heads 3 (3C, 3M, 3Y, and 3Bk) each ejecting ink of a different color. Figure 1 In the embodiment, four liquid ejection heads 3 are arranged in the following order along the X direction: 3Bk, 3Y, 3M and 3C, and ink is applied to the recording medium 2 in the following color order: black, yellow, magenta and cyan. In each individual liquid ejection head 3, a plurality of ejection ports for ejecting ink are arranged along the Y direction.

[0035] Despite Figure 1 The recording medium 2 is depicted as cut paper in FIG. 1 , but the recording medium 2 may be continuous paper fed from a paper roll. The recording medium is not limited to paper, but may be, for example, a film.

[0036] Although the first embodiment relates to a liquid ejection apparatus in which each liquid ejection head is configured to eject ink of a single color, each liquid ejection head may be configured to eject ink of a plurality of colors. Alternatively, the liquid ejection head may be configured to eject liquid other than ink, such as a reaction liquid or an overcoat agent.

[0037] Figure 2 5 is a block diagram for explaining the configuration of control performed by the liquid ejection device 1000. The controller 500 is, for example, a CPU. The controller 500 controls the overall operation of the liquid ejection device 1000 according to the program or various parameters stored in the ROM 501 while using the RAM 502 as a work area. The controller 500 performs predetermined image processing on image data received from the externally connected host device 600 according to the program and parameters stored in the ROM 501, and generates ejection data that allows the liquid ejection head 3 to perform ejection. The controller 500 drives the liquid ejection head 3 according to the ejection data, and causes ink to be ejected at a predetermined frequency.

[0038] During the ejection operation performed using the liquid ejection head 3, the controller 500 drives the transport motor 503 to transport the recording medium 2 in the X direction at a speed corresponding to the driving frequency. Thus, an image according to image data received from the host device 600 is recorded on the recording medium 2. The ROM 501 stores information about the use area for each individual liquid ejection head 3 in a rewritable manner, the information being related to which ejection ports in the liquid ejection head 3 are to be used for ejection.

[0039] Liquid circulation path

[0040] Figure 3 The liquid circulation path in the liquid ejection apparatus according to the first embodiment is schematically shown, in which the liquid ejection head 3 is fluidly connected with components such as the first circulation pump 1002 and the buffer tank 1003. Figure 3 Only the path of ink flow for the liquid ejection head corresponding to a single color of ink is depicted, but the apparatus 1000 is provided with a circulation path corresponding to each type of liquid to be ejected (eg, ink).

[0041] The buffer tank 1003 serves as a sub-tank connected to the main tank 1006. The buffer tank 1003 has an atmosphere communication port (not shown) that provides communication between the interior of the tank and the external environment. The buffer tank 1003 thus allows bubbles in the ink to be discharged to the external environment. The buffer tank 1003 is also connected to a replenishment pump 1005. For example, during recording or suction recovery performed by ejecting ink, when ink is ejected (expelled) from an ejection port in the liquid ejection head, liquid is consumed in the liquid ejection head 3. At this time, the replenishment pump 1005 transfers ink from the main tank 1006 to the buffer tank 1003 in an amount corresponding to the amount of consumed ink.

[0042] The first circulation pump 1002 is used to suck liquid from the liquid connection portion 111 of the liquid ejection head 3 and guide the liquid to the buffer tank 1003. When the liquid ejection head 3 is driven, a fixed amount of ink flows in the common collection channel 212 due to the first circulation pump 1002.

[0043] The negative pressure control unit 230 is arranged in the path between the second circulation pump 1004 and the liquid injection unit 300. The negative pressure control unit 230 is used to allow the pressure downstream of the negative pressure control unit 230 (i.e., closer to the liquid injection unit 300) to be maintained at a preset fixed pressure even when the flow rate in the circulation system fluctuates due to the difference in the duty cycle of performing recording.

[0044] like Figure 3 As shown, the negative pressure control unit 230 includes two pressure control mechanisms. Different control pressures are set for the two pressure control mechanisms. Among the two pressure control mechanisms, one pressure control mechanism (negative pressure controller 230H) with a relatively high pressure setting is Figure 3 and a pressure control mechanism with a relatively low pressure setting (negative pressure controller 230L, in Figure 3The liquid ejecting unit 300 is provided with a common supply channel 211, a common collecting channel 212, individual supply channels 213a and individual collecting channels 213b. The individual supply channels 213a and the individual collecting channels 213b are each connected to a corresponding element substrate having an ejection port. Details of the element substrate 10 will be given later. The individual channel 213 is connected to the common supply channel 211 and the common collecting channel 212. Therefore, a portion of the liquid transported by the second circulation pump 1004 reaches the common collecting channel 212 from the common supply channel 211 through the channel inside each element substrate 10 (such as Figure 3 This is because a pressure difference is provided between the pressure control mechanism H connected to the common supply channel 211 and the pressure control mechanism L connected to the common collection channel 212, and the first circulation pump 1002 is connected only to the common collection channel 212.

[0045] In this way, the following flows of liquid occur in the liquid ejection unit 300: a flow guided through the interior of the common collecting channel 212; and a flow guided from the common supply channel 211 through the interior of each element substrate 10 to the common collecting channel 212. Therefore, the flow guided from the common supply channel 211 to the common collecting channel 212 allows the heat generated in each element substrate 10 to be discharged to the outside of the element substrate 10. The above-mentioned configuration allows the flow of ink to be generated even at locations such as ejection ports or pressure chambers where recording is not performed during recording performed using the liquid ejection head 3. This helps to reduce the thickening of the ink at such locations. The above-mentioned configuration also allows the thickened ink or foreign matter in the ink to be discharged to the common collecting channel 212. Therefore, the liquid ejection head 3 according to the first embodiment is capable of high-speed and high-quality recording.

[0046] Structure of liquid ejecting head

[0047] Figure 4A and Figure 4B 1 is a perspective view of a liquid ejection head 3 according to the first 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 a line configuration). Figure 4A and Figure 4BAs shown, the liquid ejection head 3 includes a signal input terminal 91 and a power terminal 92 electrically connected to each element substrate 10 via an electrical wiring board (flexible wiring board) 40 and an electrical wiring board 90. The signal input terminal 91 and the power terminal 92 are electrically connected to a controller of the device 1000. The signal input terminal 91 and the power terminal 92 provide an ejection drive signal and power for ejection, respectively, to each element substrate 10. Integrating the wiring by using circuits within the electrical wiring board 90 allows the number of signal input terminals 91 and the number of power terminals 92 to be reduced relative to the number of element substrates 10. This helps to reduce the number of electrical connections required when installing the liquid ejection head 3 to the liquid ejection device 1000 or the number of electrical connections that need to be removed when replacing the liquid ejection head 3 from the liquid ejection device 1000. As Figure 4A As shown, the liquid connection portion 111 arranged at one side of the liquid ejection head 3 is connected to the liquid supply system of the device 1000. Due to this configuration, ink is supplied from the supply system of the device 1000 to the liquid ejection head 3, and ink that has passed through the inside of the liquid ejection head 3 is collected to the supply system of the device 1000. In this way, the ink is allowed to circulate through the path in the device 1000 and the path in the liquid ejection head 3.

[0048] Figure 5 3 is an exploded perspective view of the liquid ejection head 3, showing the components or units constituting the liquid ejection head 3. The liquid ejection unit 300, the liquid supply unit 220, and the electrical wiring board 90 are mounted to the housing 80. The liquid supply unit 220 is provided with a liquid connection portion 111. The filter 221 ( Figure 3 ) is arranged inside the liquid supply unit 220 to remove foreign matter present in the ink being supplied. The filter 221 is communicated with each opening of the liquid connection portion 111. 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 includes a unit having a pressure control valve, and uses the action of the valve, spring member, etc. in each unit to greatly reduce the pressure loss change in the supply system of the device 1000 (the upstream supply system of the liquid ejection head 1) that may occur with the change in the flow rate of the liquid.

[0049] Therefore, the change of negative pressure downstream of the negative pressure control unit 230 (near the liquid injection unit 300) can be stabilized within a given fixed range. Two pressure control valves are built into the negative pressure control unit 230. Each of the pressure control valves is set to a different control pressure. Among the pressure control valves, one pressure control valve with a higher pressure setting and one pressure control valve with a lower pressure setting are respectively connected to the common supply channel 211 and the common collection channel 212 located in the liquid injection unit 300 via the liquid supply unit 220.

[0050] The housing 80 includes a liquid ejection unit support portion 81 and an electric wiring board support portion 82 to respectively support the liquid ejection unit 300 and the electric wiring board 90, and also to ensure the rigidity of the liquid ejection head 3. The electric wiring board support portion 82 for supporting the electric wiring board 90 is fixed by being screwed to the liquid ejection unit support portion 81. The liquid ejection unit support portion 81 has openings 83 and 84 into which the joint rubber 100 is to be inserted. The liquid supplied from the liquid supply unit 220 is introduced into the second channel member 60 constituting the liquid ejection unit 300 via the joint rubber 100.

[0051] The configuration of the channel member 210 included in the liquid ejecting unit 300 will now be described. Figure 5 As shown, in the channel member 210, the first channel member 50 and the second channel member 60 are stacked on each other. A plurality of jet modules 200 are bonded to the bonding surface of the first channel member 50 using an adhesive (not shown). The channel member 210 is a channel member for distributing the liquid supplied from the liquid supply unit 220 to the jet modules 200 and returning the liquid from the jet modules 200 to the liquid supply unit 220. The channel member 210 is fixed by being screwed onto the liquid jet unit support portion 81. This reduces warping or deformation of the channel member 210.

[0052] FIG. 6A to FIG. 6D The construction of the channel member 210 is shown in detail. Fig. 6A There is shown a support member 30 which is arranged on a surface of the first channel member 50 on which the injection module 200 is to be mounted. Figure 6B The surface of the first channel member 50 that is in contact with the support member 30 is shown. Figure 6C φ is a cross section of the first channel member 50 taken along a plane perpendicular to the Z direction and close to the center in the Z direction. Fig.6D The surface of the second channel member 60 that is in contact with the liquid ejecting unit supporting portion 81 is shown. FIG. 6A to FIG. 6C is a view from the injection module 200, and Fig.6D This is a view viewed from the liquid ejecting unit supporting portion 81 .

[0053] A plurality of support members 30 are arranged on the surface of the first channel member 50 opposite to the second channel member 60. The support members 30 are arranged in the Y direction. A single element substrate 10 is arranged on each support member 30. Adjusting the number of ejection modules 200 to be arranged makes it possible to form liquid ejection heads 3 of various sizes.

[0054] like Fig. 6A As shown, each support member 30 has a communication port 31 on its surface in contact with the element substrate 10. The communication port 31 is fluidly connected to the element substrate 10 and will be used as a reference above. Figure 3 The separate supply channel 213a and the separate collection channel 213b are described. Figure 6B As shown, the communication port 31 is in fluid communication with the common supply channel 211 or the common collection channel 212 via the communication port 51 of the first channel member 50 .

[0055] like Figure 6C As shown, in the middle layer near the center in the Z direction of the first channel member 50, the Figure 3 The common channels 61 and 62 of the common supply channel 211 and the common collection channel 212 are described to extend in the Y direction. Fig.6D As shown, the common communication port 63 is arranged at both ends or one end of the common passages 61 and 62 .

[0056] Fig. 7A and Figure 7B 3 and 4 are a perspective view and a cross-sectional view, respectively, of a channel structure defined inside the liquid ejecting unit 300 . Fig. 7A is an enlarged perspective view of the channel member 210 viewed along the Z direction, and Figure 7B is along Fig. 7A A cross-sectional view taken along line VIIB-VIIB.

[0057] The element substrate 10 of the injection module 200 is placed above the communication port 51 of the first channel member 50 with the support member 30 interposed therebetween. Figure 7B Only the communication port 51 corresponding to the common supply channel 211 is depicted, but when viewed in another cross section, the common collection channel 212 and the communication port 51 are as shown in FIG. Figure 6B and Figure 6C The support member 30 and the element substrate 10 included in each injection module 200 each define therein a channel for transmitting heat from the first channel member 50 to the heat generating resistor element 15 (reference Fig. 9B ) A channel for supplying ink. In addition, the support member 30 and the element substrate 10 each define therein a channel for collecting (recirculating) a part or all of the liquid supplied to the heat generating resistor element 15 to the first channel member 50 .

[0058] As described above, the common supply channel 211 is connected to the negative pressure controller 230H at a relatively high pressure, and the common collection channel 212 is connected to the negative pressure controller 230L at a relatively low pressure. Fig.6D), the common supply channel 211 and the communication port 31 to supply ink to the channels defined in the element substrate 10. Similarly, an ink collection path is formed from the channels in the element substrate 10 through the communication port 31, the communication port 51, the common collection channel 212 and the common communication port 63 (see Fig.6D ). While the ink is circulated in this manner, an ejection operation is performed in the element substrate 10 according to the ejection data. At this time, a portion of the ink supplied through the ink supply path is not consumed by the ejection operation. The unconsumed portion of the ink is collected through the ink collection path.

[0059] The structure of the injection module

[0060] Fig. 8A is a perspective view of a spray module 200, and Figure 8B : is an exploded view of the injection module 200. The injection module 200 is manufactured by the method described below. First, the element substrate 10 and the flexible wiring board 40 are bonded to the support member 30 pre-provided with the communication port 31. Subsequently, the electrode pads 16 on the element substrate 10 and the terminals 41 on the flexible wiring board 40 are electrically connected by wire bonding, and then the wire bonding portion (electrical connection portion) is covered and sealed with a sealant 110. As the flexible wiring board 40, for example, copper foil is bonded to a polyimide tape with an adhesive, and then patterned to form wiring for electrical connection to the electrode pads 16 on the element substrate 10. The terminals 42 located at the side of the flexible wiring board 40 opposite to the element substrate 10 are electrically connected to the connection terminals 93 of the electrical wiring board 90 (see Figure 5 ). The support member 30 serves as a support for supporting the element substrate 10, and also serves as a channel member for providing fluid communication between the element substrate 10 and the channel member 210. Therefore, the support member 30 that can be appropriately used may be a support member that has high flatness and can be bonded to the element substrate with sufficient reliability. The support member 30 may be made of, for example, alumina or a resin material. Details on the sealing of the electrical connection portion will be given later.

[0061] Component substrate structure

[0062] Next, the configuration of the element substrate 10 according to the first embodiment will be described. Fig.9A It is a plan view of the surface of the element substrate 10 on which the ejection ports 13 are provided. Fig. 9B yes Fig.9A Magnified view of section IXB in FIG. Fig. 9C is with Fig.9A A plan view of the back side opposite to the surface shown in . Fig.10 is along Fig.9A1 is a cross-sectional perspective view of the element substrate 10 taken along line XX of FIG. 1. Hereinafter, the direction in which the ejection port array including the arrangement of the plurality of ejection ports 13 extends will be referred to as an "ejection port array direction".

[0063] like Fig. 9B As shown, the heat generating resistor elements 15 are arranged at positions corresponding to the associated ejection ports 13. Each heat generating resistor element 15 serves as a heating element (pressure generating element) for generating bubbles in the liquid by using the heat energy generated by the heat generating resistor element 15. The pressure chambers 23 are separated from each other by partition walls 22 defined by a first layer 121 (described later) of the channel forming member 12. Each pressure chamber 23 includes a heat generating resistor element 15 arranged therein. The heat generating resistor element 15 is electrically connected to the electrode pad 16 via an electrical wiring (not shown) provided to the element substrate 10. The heat generating resistor element 15 is electrically connected to the electrode pad 16 via an electrical wiring board 90 (see FIG. 1 ) based on the control circuit of the liquid ejection device 1000. Figure 5 ) and the flexible wiring board 40 (see Fig. 8A and Figure 8B ) The pulse signal input generates heat to boil the liquid. The force of the bubbles generated by boiling causes the liquid to be ejected from the ejection port 13. Fig. 9B As shown, along each ejection port array, the liquid supply passage 18 extends on one side, and the liquid collection passage 19 extends on the other side. The liquid supply passage 18 and the liquid collection passage 19 are channels extending in the direction of each ejection port array arranged on the element substrate 10. The liquid supply passage 18 and the liquid collection passage 19 are communicated with the corresponding ejection port 13 via the supply port 17a and the collection port 17b, respectively. 9A to 9C An example is shown in which the element substrate 10 has 16 ejection port arrays.

[0064] like Fig. 9C and Fig.10 As shown in FIG. 1 , a cover plate 20 in the form of a sheet is stacked on the back surface of the element substrate 10 opposite to the surface on which the ejection port 13 is provided. Fig. 9C As shown, the cover plate 20 is provided with a plurality of openings 21 (described later) communicating with the liquid supply passage 18 and the liquid collection passage 19. According to the first embodiment, four supply openings 21a are provided for each single liquid supply passage 18, and three collection openings 21b are provided for each single liquid collection passage 19. However, the above number of these openings is not intended to be restrictive. Fig. 9B As shown, each opening 21 in the cover plate 20 is Fig. 7AThe cover plate 20 is connected to the corresponding communication port 51 shown. The cover plate 20 can be made of a material having sufficient corrosion resistance with respect to the liquid. In addition, high precision is required for the shape and position of the opening 21 to allow ink to be supplied to the pressure chamber. To this end, the cover plate 20 can be made of a material such as a photosensitive resin material or silicon, and the opening 21 can be formed by photolithography. As described above, the cover plate 20 is used to change the channel spacing by using the opening 21. From the perspective of pressure loss, strength and processability, the cover plate 20 to be used can be a film-like member with a thickness of about 30 to 600 μm (micrometers).

[0065] The flow of liquid within the element substrate 10 will now be described. The element substrate 10 is a laminate of a substrate 11 made of silicon and a channel forming member (ejection port forming member) 12 made of a photosensitive resin. According to the first embodiment, the channel forming member 12 has a first layer 121 (intermediate layer) for defining a pressure chamber 23 and a second layer 122 (lower layer) including the ejection port 13. The first layer 121 and the second layer 122 are laminated in this order on the surface (first surface 11a) of the substrate 11, and are patterned by exposing to light at the respective optimal light-sensitive wavelengths of these layers, followed by development, thereby forming the channel forming member 12. As a manufacturing method for the channel forming member 12 other than the above-described method of laminating the first layer and the second layer, any appropriate manufacturing method may be used, for example, by forming the pressure chamber and the ejection port using, for example, a mold material.

[0066] The cover plate 20 is bonded to the back surface of the substrate 11. The cover plate 20 serves as a cover for a portion of the respective walls defining the liquid supply path 18 and the liquid collection path 19 provided in the substrate 11 of the element substrate 10. In the element substrate 10, one surface of the substrate 11 is provided with a heat generating resistor element 15 (see Fig. 9B ), and the back side of the substrate 11 opposite to the one surface is provided with grooves extending along each ejection port array defining a liquid supply passage 18 and a liquid collection passage 19. The liquid supply passage 18 and the liquid collection passage 19 defined by the substrate 11 and the cover plate 20 are respectively connected to a common supply passage 211 and a common collection passage 212 provided in a channel member 210 (see Fig. 7A and Figure 7B There is a pressure difference between the liquid supply passage 18 and the liquid collection passage 19. Due to the pressure difference, a circulation flow C is formed in which the liquid in the liquid supply passage 18 provided in the substrate 11 flows to the liquid collection passage 19 (at Fig.10The above flow makes it possible to collect thickened ink, bubbles, foreign matter, and other substances due to evaporation through the ejection port 13 to the liquid collection path 19 for the ejection port 13 and the pressure chamber 23 that do not perform the ejection operation. The above flow also makes it possible to reduce, for example, the thickening of the ink at a location such as the ejection port 13 or the pressure chamber 23, or the increase in the concentration of the colorant of the ink. Fig. 7A and Figure 7B As shown, the liquid collected in the liquid collection passage 19 is collected in the supply path of the liquid injection device 1000 via the opening 21 in the cover plate 20 and the connecting port 31 of the supporting member 30 by flowing through the following components in the following order: the connecting port 31 of the supporting member 30; the connecting port 51 of the first channel member 50; and the common collection channel 212.

[0067] That is, the liquid supplied from the main body of the liquid ejection device to the liquid ejection head 3 is supplied and collected by flowing in the order described below. First, the liquid flows from the liquid connection portion 111 of the liquid supply unit 220 into the liquid ejection head 3. Then, the liquid is supplied by passing through the following components in the following order: the joint rubber 100; the common communication port 63 provided in the second channel member; and the common channel 61 and the communication port 51 provided in the first channel member. Subsequently, the liquid is supplied to the pressure chamber 23 by passing through the following components in the following order: the communication port 31 provided in the support member 30; the opening 21 provided in the cover plate 20; and the liquid supply passage 18 and the supply port 17a provided in the substrate 11. A portion of the liquid supplied to the pressure chamber 23 is not ejected from the ejection port 13. This un-ejected liquid flows through the following components in the following order: the collection port 17b and the liquid collection passage 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. Subsequently, the liquid flows through the following components in the following order: the communication port 51 and the common channel 62 provided in the first channel member; the common communication port 63 provided in the second channel member; and the joint rubber 100. Then, the liquid flows from the liquid connection portion 111 provided to the liquid supply unit to the outside of the liquid ejection head 3. Figure 3 In the configuration of the circulation path shown, the liquid entering from the liquid connection portion 111 passes through the negative pressure control unit 230 before being supplied to the joint rubber 100 .

[0068] The liquid ejection head according to the first embodiment further includes a temperature control mechanism (not shown) provided to the element substrate 10. The element substrate 10 is divided into a plurality of regions for temperature control. A temperature sensor and an individually controllable sub-heater are provided for each individual region. The controller 500 (see Figure 2) Temperature control is performed by using a temperature sensor and a sub-heater based on a temperature (target temperature) set for each individual area. That is, the controller 500 drives the sub-heater only for an area where the temperature detected by the temperature sensor is less than or equal to the target temperature. Setting a reasonably high target temperature for the element substrate 10 makes it possible to reduce the viscosity of the ink, and thus the ejection operation or cycle can be performed in an appropriate manner. Through this temperature control, the deviation (for example, the temperature deviation within the element substrate 10, or the temperature deviation between multiple element substrates 10) is maintained within a predetermined range. This makes it possible to reduce the deviation of the ejection amount caused by the temperature deviation and reduce the density unevenness in the recorded image. The target temperature of the element substrate 10 can be set to a temperature approximately equal to or higher than the equilibrium temperature of the element substrate 10 reached when all the heating resistor elements 15 are driven at the highest assumed driving frequency. As a temperature sensor, a diode sensor, an aluminum sensor or other sensors can be used. As a heating unit for heating the element substrate 10, a heating resistor element 15 (which is a heating element) can be used. More specifically, the element substrate 10 can be heated by applying a voltage that is not high enough to cause bubbles to be generated to the heating resistor element 15. For example, as the heating unit, the heat generating resistor element 15 may be used instead of the sub-heater, or the sub-heater and the heat generating resistor element 15 may be used in combination.

[0069] Flow of liquid near the pressure chamber

[0070] Fig.11A and Fig. 11B The interior of the liquid ejection head is shown. Fig.11A The heating resistor elements and channels are shown in plan view (perspective view). Fig. 11B is along Fig.11A The following components are arranged between the substrate 11 of the element substrate 10 and the channel forming member 12: a plurality of pressure chambers 23, each of which includes an ejection port 13; and an inlet passage 24a and an outlet passage 24b communicating with each pressure chamber 23. Each pressure chamber 23 is separated by a partition wall 22 of the channel forming member 12. In the substrate 11, when the liquid in the liquid supply passage 18 flows to the liquid collection passage 19 via the supply port 17a, the inlet passage 24a, the pressure chamber 23, the outlet passage 24b and the collection port 17b, a circulation flow C is formed (see Fig.10 ). The speed of the circulating flow C in the pressure chamber may be, for example, greater than or equal to 1.0 mm / s and less than or equal to 250 mm / s (millimeter per second). Even when the spraying operation is performed while the liquid is flowing, the speed within this range does not significantly affect, for example, the landing accuracy of the droplets. Fig. 11BAs shown, the injection port 13 is an opening defined in the channel forming member 12 and located at the end of the nozzle 25 having a tubular shape. The nozzle 25 provides communication between the injection port 13 and the pressure chamber 23. The direction in which the liquid is ejected from the injection port 13 ( Fig. 11B The vertical direction in the pressure chamber 23 is referred to as the “injection direction”, and the direction in which the liquid flows in the pressure chamber 23 ( Fig. 11B The horizontal direction in the image is referred to as the “flow direction”.

[0071] The plurality of supply ports 17a form a supply port array, and the plurality of collection ports 17b form a collection port array. An ejection port array including an arrangement of the plurality of ejection ports 13 is provided between the supply port array and the collection port array.

[0072] As described above, according to the first embodiment, a pressure difference is provided between the liquid supply passage 18 and the liquid collection passage 19. This pressure difference generates a circulation flow C in which ink is introduced from the supply port 17a to the pressure chamber 23 through the inlet passage 24a, and ink flows from the outlet passage 24b to the collection port 17b.

[0073] The heat generating resistor element 15 is arranged at the bottom surface of the pressure chamber 23 facing the ejection port 13. The nozzle (ejection port) 25 extends through the passage forming member 12 at a position where the nozzle (ejection port) 25 faces the pressure chamber 23.

[0074] The outer end of the nozzle 25 (i.e., the end opposite to the heat generating resistor element 15) defines the ejection port 13 through which the ink is ejected. The nozzle 25 or the ejection port 13 is positioned to face the heat generating resistor element 15. As used herein, the term "ejection port 13" refers to an opening located in the outer surface of the channel forming member 12 facing the recording medium 2, and the term "nozzle 25" refers to a portion that provides communication between the ejection port 13 and the pressure chamber 23, and is a through hole extending through the channel forming member 12.

[0075] like Fig.11A and Fig. 11B As shown, according to the first embodiment, the liquid ejection head does not include a filter, for example in the form of a columnar structure, which is usually arranged in the channel in the liquid ejection head to prevent foreign matter such as dust from entering the pressure chamber 23. This configuration makes it possible to reduce the flow resistance in the channel and improve the ink refilling performance. This in turn can allow, for example, an increased ejection frequency. According to the present disclosure, foreign matter can be captured by a channel (inlet passage 24a) having a relatively small height in the channel forming member. This makes it possible to omit the filter.

[0076] Shape of injection port

[0077] Fig. 12AThe shape of the injection port 13 according to the first embodiment is shown in a plan view. Fig. 12B Another example of the shape of the injection port 13 is shown in plan view. Fig. 12A As shown, according to the first embodiment, two protrusions 27 are arranged on a straight line L passing through the center F of the injection port 13. The protrusions 27 have the same shape and are located on opposite sides relative to the center F. The protrusions 27 protrude toward the center F. This can advantageously lead to a reduction in the tail length of the ejected droplets. This will be explained in more detail below. The meniscus of the ink formed between the protrusions 27 is easy to maintain compared to the meniscus at other positions. Therefore, the tail of the droplet extending from the injection port 13 can be cut off at an earlier moment. This makes it possible to reduce the generation of mist consisting of tiny droplets following the main droplet. Figures 1 to 11B In some cases, the injection port 13 may be depicted with the protrusion 27 omitted. Larger intervals 28 between the protrusions 27 tend to result in longer tails of the ejected droplets and result in the formation of small satellite droplets. Therefore, the interval 28 is ideally less than or equal to 7.0 μm, and more ideally less than or equal to 5.0 μm. However, in some cases, too small an interval may make the formation or shaping of the protrusion difficult, or cause the ejected droplets to split in half. Therefore, the interval 28 may be greater than or equal to 2.0 μm. That is, the interval 28 is ideally greater than or equal to 2.0 μm and less than or equal to 7.0 μm, and more ideally greater than or equal to 2.0 μm and less than or equal to 5.0 μm. In one example of the first embodiment, the interval 28 is set to 3.0 μm.

[0078] If each protrusion 27 has a thicker tip (closer to the center F), this may cause the ejected droplet to be split into two droplets by the protrusion 27 in some cases. Therefore, the width 271 at the tip portion of the protrusion 27 may be less than or equal to 4.0 μm. In one example of the first embodiment, the width 271 is 2.0 μm. If Fig. 12A In the case of the first embodiment shown in FIG. 1 , the protrusions have rounded ends, so Fig. 12A As shown by the dotted line in , the width 271 of the end portion thereof can be regarded as the length of a line segment obtained by cutting a line located at the end of the protrusion and orthogonal to the straight line L at the intersection of a line located at the end of the protrusion and orthogonal to the straight line L and two lines that are extensions of the two long sides of the protrusion. In addition, from the perspective of increasing the strength of the protrusion 27, the width 272 at the root portion of the protrusion 27 can be greater than the width 271 at the end portion. In one example of the first embodiment, the width 272 is 4.0 µm. If as Fig. 12A In the case of the first embodiment shown in FIG. 1 , the injection port 13 has a curved shape at the root portion. Fig. 12AAs shown by the dotted line in FIG. 2 , the width 272 at the root portion can be regarded as the length of a line segment connecting two intersection points between: the circumference line of the ejection port 13 when the ejection port 13 has a circular shape; and two lines that are extensions of the two long sides of the protrusion. As described above, from the perspective of droplet formation, the protrusion 27 can have a shape that narrows from the root portion toward the end portion. The protrusion 27 can have a shape such as Fig. 12B The arc shape shown.

[0079] The above-mentioned two protrusions 27 can extend in a direction substantially parallel to the conveying direction (X direction) of the recording medium 2. Since the protrusion 27 has a very significant effect on the droplet ejection, a slight manufacturing deviation between the shapes of the two protrusions can cause the droplet to deviate toward one of the protrusions during its flight. This causes a landing position offset. Generally, the landing position offset in the direction of arrangement of the ejection ports (Y direction) is more visually obvious on the image than the landing position offset in the conveying direction (X direction) of the recording medium. Therefore, orienting the protrusion to be substantially parallel to the conveying direction of the recording medium 2 advantageously makes it possible to reduce the offset in the direction of arrangement of the ejection ports, and thus maintain satisfactory print quality. The protrusion 27 can extend in the direction of liquid flow near the pressure chamber. In other words, the straight line L where the protrusion is located can have an angle of less than or equal to 45 degrees relative to the channel axis connecting the liquid supply passage 18 and the liquid collection passage 19 or connecting the inlet passage 24a and the outlet passage 24b.

[0080] According to the first embodiment, as described below, two protrusions 27 extend toward the center F of the injection port. In this regard, the presence of only one such protrusion 27 can still provide satisfactory droplet formation. However, in this case, the landing position may become significantly offset toward the position where the protrusion 27 is not present, which potentially leads to a decrease in the stability of the landing position. Therefore, the two protrusions 27 can be set to extend toward the center F of the injection port. The present disclosure can also be appropriately applied to a liquid injection head whose injection port does not have a protrusion 27.

[0081] Furthermore, in order to achieve satisfactory image quality with stable ejection quality, the landing size of the droplet landing on the recording medium 2 can be made relatively small to allow high definition. Therefore, for the liquid ejection head according to the first embodiment, the ejection amount is set to a relatively small value of 2.0 ng.

[0082] Positional relationship between component substrates

[0083] Fig.13 FIG. 1 is a partially enlarged plan view of the adjacent portions of the respective element substrates of two adjacent injection modules. Fig.9A and Fig. 9CAs shown in FIG. 1 , the outer shape of the element substrate 10 according to the first embodiment is substantially a parallelogram. Fig.13 As shown, each element substrate 10 is provided with an ejection port array (14a to 14d), each ejection port array including an arrangement of ejection ports 13. Each ejection port array is inclined at a fixed angle relative to the direction of the recording medium 2. Due to this configuration, at a position where the element substrates 10 are adjacent to each other, at least one ejection port 13 of one ejection port array and at least one ejection port 13 of another ejection port array overlap each other in the conveying direction of the recording medium 2. Fig.13 In the embodiment, two ejection ports located on line D are in an overlapping relationship with each other. Due to this arrangement, even if the element substrate 10 is slightly deviated from the predetermined position, controlling the driving of the ejection ports that overlap each other allows the black streaks or white lines in the recorded image to be less noticeable. That is, even when a plurality of element substrates 10 are arranged in a line arrangement rather than a staggered arrangement in order to reduce the increase in the length of the liquid ejection head 3 in the conveying direction of the recording medium 2, the use of Fig.13 The illustrated configuration also makes it possible to resolve black streaks or white lines in the overlapping portion of the element substrate 10. According to the first embodiment, the main surface of the element substrate 10 has a parallelogram shape. However, this is not intended to limit the present disclosure. The configuration according to the present disclosure can also be applied to an element substrate whose main surface has other shapes (e.g., a rectangle or a trapezoid).

[0084] Structure to prevent sealant from flowing

[0085] The problem to be solved by the present disclosure will be described below in detail with reference to how the electrical connection portion 70 is sealed in the injection module 200. As described above, the electrical connection portion (wire bonding portion) between the element substrate and the electrical wiring board is covered by the sealant 110. The flow of the sealant during its application causes incomplete coverage of the wire. In order to solve this problem, some liquid injection heads according to the prior art include a structure 701 provided by using an adhesive layer for improving the adhesion between the substrate 11 and the channel forming member 12 (or the first layer 121). The structure 701 serves as a wall for preventing the sealant 110 from flowing to the outside of the substrate 11. Fig.14A 1 is a plan view of a component substrate 10 according to the prior art. Fig.14AIn the plan view of the element substrate, a structure 701 made of the same material as that of the adhesive layer 700 is arranged between an electrode pad array 161 (which is an array of electrode pads 16 arranged along one side of the substrate 11) and the one side of the substrate 11. However, a potential problem with this configuration is that since the adhesive layer 700 generally has a small thickness of 1 to 2 μm, the sealant 110 may flow over the structure 701 to the outside of the substrate. In order to solve this problem, according to the present disclosure, the above-mentioned wall for preventing the sealant 110 from flowing to the outside of the substrate 11 is formed by using a channel forming member 12.

[0086] FIG. 15A to FIG. 15C The element substrate 10 according to the first embodiment is shown. According to the first embodiment, a structure 123 is provided between the electrode pad array 161 and one side of the element substrate 10. The structure 123 is made of the same material as the material of the channel forming member 12, and serves as a wall for preventing the sealant from flowing from a position where the sealant has been applied. As described above, the structure 123 serving as a wall for preventing the sealant from flowing is formed by using the same layer as the channel forming member 12. This makes it possible to further prevent the flow of the sealant 110 without increasing the number of manufacturing steps and by using a wall having a height higher than the adhesive layer 700.

[0087] As mentioned above, the adhesive layer 700 is a layer made of resin provided to improve the adhesion between the channel forming member 12 and the substrate 11. The adhesive layer may contain a resin, for example, may contain at least one of a polyimide resin and a polyetheramide resin. When the adhesive layer 700 made of a resin is provided, the adhesive layer 700 is applied to the substrate 11 in its liquid form. This places restrictions on the manufacturing process, for example, it is necessary to apply an adhesive layer before forming features such as a channel or a pressure chamber by patterning the channel forming member 12. If the adhesion between the channel forming member 12 and the substrate 11 is good, it is not necessary to provide the adhesive layer 700, in which case the first layer 121 may be arranged to contact the first surface 11a of the substrate 11. Compared with the case where the adhesive layer is provided, this configuration has the advantages of fewer restrictions imposed on the manufacturing process and reducing the number of manufacturing steps. In order to improve the adhesion of the first layer 121 to the substrate, for example, the first layer 121 may be made of a resin containing polyethylene glycol. Fig. 15B is a plan view of the element substrate 10 according to the first embodiment without the adhesive layer 700 being provided. Fig. 15C is with Fig. 15B The position indicated by the line XVC-XVC in FIG. 2 corresponds to the cross section of the injection module 200. However, it should be noted that Fig. 15C The support member 30 is not shown.

[0088] The structure 123 may have a height greater than or equal to 3 μm and less than or equal to 25 μm in a direction perpendicular to the substrate 11. One reason for this is that the height of the structure 123 is too small so that the sealant 110 is more likely to be formed. Fig.14A and Fig. 14B Another reason is that the height of structure 123 is too large, making it more difficult to apply sealant 110 to fill the area near electrical connection 70, or to form electrical connection 70. Fig. 15C In the embodiment, the structure 123 is formed only by the first layer 121 of the channel forming member. This configuration can make it easier for the structure 123 to have a height that makes it easier to prevent the flow of the sealant 110 and to easily form the electrical connection portion 70.

[0089] Distance L1, which is the distance between structure 123 and the end of the side of substrate 11 along which electrode pad array 161 is arranged, may be greater than or equal to 2 μm and less than or equal to 200 μm. In particular, in some cases, a greater distance between the end of substrate 11 and structure 123 tends to result in a greater distance between the end of substrate 11 and electrode pad array 161, which in turn tends to make it difficult to form electrical connection 70.

[0090] like Fig. 15C As shown, in a direction parallel to the first surface 11a and orthogonal to the direction in which the electrode pad array 161 extends, the distance between the first layer 121 and the electrode pad array 161 is smaller than the distance between the second layer 122 and the electrode pad array 161. That is, when viewed in a cross section orthogonal to the electrode pad array 161, the first layer 121 and the second layer 122 are in a stepped configuration. This configuration increases the contact area of ​​the sealant 110 with the first layer 121, and thus allows the adhesion of the sealant 110 to the element substrate 10 to be increased. In particular, if the second layer 122 has a waterproof layer on the surface where the injection port 13 is present, the adhesion between the second layer 122 and the sealant 110 is poor. The above-mentioned stepped configuration of the first layer 121 and the second layer 122, which allows the contact area between the sealant 110 and the first layer 121 to be increased, is particularly advantageous for this case. In a direction parallel to the first surface 11a and orthogonal to the direction in which the electrode pad array 161 extends, the distance L2 (which is the distance between the end of the first layer 121 close to the electrode pad array 161 and the end of the second layer 122 close to the electrode pad array 161) can be, for example, 1 to 2000µm.

[0091] The following description of the embodiment focuses on the differences from the first embodiment described above, and features similar to those described above will not be described in further detail.

[0092] Second embodiment

[0093] Fig.16A and Fig. 16B An element substrate 10 according to a second embodiment is shown. Fig.16A The element substrate 10 without the adhesive layer is shown. Fig. 16B The element substrate 10 having an adhesive layer is shown. FIG. 15A to FIG. 15C In the case of the configuration of the first embodiment shown in , the sealant may flow to the outside of the element substrate 10 along the arrangement direction of the electrode pads 16 in some cases. In order to solve this problem, according to the second embodiment, as shown in Fig.16A and Fig. 16B As shown in FIG, the structure 123 made of the same material as the first layer 121 is arranged on opposite sides in the arrangement direction of the electrode pads 16, and is arranged between the side of the element substrate 10 and the electrode pads 16. That is, in the plan view of the element substrate 10, the structure 123 is positioned to surround the electrode pad array.

[0094] Third embodiment

[0095] Fig.17A and Fig. 17B An element substrate 10 according to a third embodiment is shown. Fig.17A The element substrate 10 without the adhesive layer is shown. Fig. 17B An element substrate 10 having an adhesive layer is shown. Fig. 17C is with Fig. 17B . According to the third embodiment, the first layer 121 is provided on substantially the entire first surface 11a of the element substrate 10, and the first layer 121 is removed only around the electrode pad array 161. In other words, in the plan view of the substrate 11, the electrode pad array 161 is located within the opening 124 provided in the first layer 121. Therefore, the area of ​​the substrate 11 covered by the first layer 121 increases relative to the first and second embodiments. This can lead to improved protection of the substrate 11. In other words, the area of ​​the substrate 11 covered only by the sealant 110 is reduced relative to the first and second embodiments. This can lead to improved protection of the substrate 11. In this regard, in a direction parallel to the first surface 11a, on one side of the electrode pad array 161 close to the area where the ejection port is present, the first layer 121 and the electrode pad array 161 can have a distance L3 greater than or equal to 2μm and less than or equal to 200μm relative to each other.

[0096] exist Fig.17A and Fig. 17B, the second layer 122 provided with the ejection port 13 is arranged only in the region where the ejection port 13 exists, and the opening 124 is provided only in the first layer 121. However, alternatively, the channel forming member 12 may be arranged on substantially the entire first surface 11a of the substrate 11, and both the first layer 121 and the second layer 122 may be provided with the opening 124.

[0097] Fourth embodiment

[0098] Fig.18A and Fig.18B An element substrate 10 according to a fourth embodiment is shown. Fig.18A The element substrate 10 without the adhesive layer is shown. Fig.18B The element substrate 10 with the adhesive layer is shown. According to the fourth embodiment, the element substrate 10 is provided with a plurality of openings 124 at which the first layer 121 is removed. The openings 124 correspond to the respective associated electrode pads 16. FIG. 17A to FIG. 17C In the third embodiment shown in FIG, the area of ​​the substrate 11 covered by the first layer 121 increases. This can lead to improved protection of the substrate 11. In this case, for example, in a direction parallel to the first surface 11a, the first layer 121 and the electrode pad array 161 can have a distance greater than or equal to 2 μm and less than or equal to 20 μm relative to each other.

[0099] As long as a single element substrate 10 has a plurality of openings 124, a plurality of electrode pads 16 may be arranged in each single opening 124. This configuration may also provide improved protection of the substrate compared to the configuration in which all electrode pads 16 are arranged in a single opening provided in the first layer 121 according to the third embodiment described above.

[0100] exist Fig.18A and Fig.18B , the second layer 122 provided with the ejection port 13 is arranged only in the region where the ejection port 13 exists, and the plurality of openings 124 are provided only in the first layer 121. However, alternatively, the channel forming member 12 may be arranged on substantially the entire first surface 11a of the substrate 11, and both the first layer 121 and the second layer 122 may be provided with the openings 124.

[0101] The present disclosure provides a liquid ejection head that prevents a sealant from flowing from a position to which the sealant has been applied and provides improved electrical reliability.

[0102] While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the present disclosure is not limited to the disclosed exemplary embodiments.The scope of the following claims is to be accorded the broadest interpretation so as to encompass all modifications and equivalent structures and functions.

Claims

1. A liquid ejection head, comprising: A component substrate, the component substrate comprising: a substrate having a first surface, an element configured to spray a liquid, a channel forming member including a pressure chamber and an ejection port which is a port communicating with the pressure chamber and through which the liquid is ejected, and a pad array, the pad array comprising a plurality of pads electrically connected to the element, the plurality of pads being arranged along one side of the substrate, The element, the channel forming member and the pad array are arranged at the first surface of the substrate; an electrical wiring board connected to each of the plurality of pads via an electrical connection; and a sealant disposed on the first surface of the substrate and surrounding the electrical connection, Wherein, in a plan view of the element substrate, the channel forming member has an opening, and the pad array is located within the opening.

2. The liquid ejecting head according to claim 1, in, The channel forming member comprises: a first layer disposed on one side of the first surface and defining the pressure chamber; and a second layer disposed on a side of the first layer opposite to the substrate, the second layer having the ejection port, and Wherein, the opening is arranged in the first layer.

3. The liquid ejecting head according to claim 2, in, In a direction perpendicular to the substrate, the first layer has a height greater than or equal to 3 μm and less than or equal to 25 μm (micrometers).

4. A liquid ejection head, comprising: A component substrate, the component substrate comprising: a substrate having a first surface, an element configured to spray a liquid, a channel forming member including a pressure chamber and an ejection port which is a port communicating with the pressure chamber and through which the liquid is ejected, and a pad array, the pad array comprising a plurality of pads electrically connected to the element, the plurality of pads being arranged along one side of the substrate, The element, the channel forming member and the pad array are arranged at the first surface of the substrate; an electrical wiring board connected to each of the plurality of pads via an electrical connection; and a sealant disposed on the first surface of the substrate and surrounding the electrical connection, Wherein, when viewed in a direction perpendicular to the substrate, the liquid ejection head includes a structure arranged between the one side and the pad array, and the structure and the channel forming member are made of the same material.

5. The liquid ejecting head according to claim 4, in, In a direction perpendicular to the substrate, the structure has a height greater than or equal to 3 μm and less than or equal to 25 μm (micrometers).

6. The liquid ejecting head according to claim 5, in, The channel forming member comprises: a first layer disposed on one side of the first surface and defining the pressure chamber; and a second layer disposed on a side of the first layer opposite to the substrate, the second layer having the ejection port, and Wherein, the structure and the first layer are made of the same material.

7. The liquid ejecting head according to claim 4, in, In a plan view of the element substrate, the structure is positioned to surround each of the plurality of pads.

8. The liquid ejecting head according to claim 2 or 6, in, In a direction parallel to the first surface and orthogonal to the direction in which the pad array extends, on a side of the pad array close to the injection port, a distance between the first layer and the pad array is smaller than a distance between the second layer and the pad array.

9. The liquid ejecting head according to claim 2 or 6, in, In a direction parallel to the first surface and orthogonal to a direction in which the pad array extends, the first layer and the pad array have a distance relative to each other greater than or equal to 2 μm and less than or equal to 200 μm (micrometers).

10. The liquid ejecting head according to claim 1 or 4, in, The electrical connection is a wire.

11. The liquid ejecting head according to claim 1 or 4, in, The passage forming member is made of resin.

12. The liquid ejecting head according to claim 2 or 6, in, The first layer is arranged in contact with the first surface of the substrate.

13. The liquid ejecting head according to claim 2 or 6, in, The first layer is arranged at the first surface, wherein an adhesive layer is interposed between the first layer and the first surface.

14. The liquid ejecting head according to claim 2 or 6, in, The first layer includes polyethylene glycol.

15. A method for manufacturing a liquid ejecting head, The liquid ejecting head comprises: A component substrate, the component substrate comprising: a substrate having a first surface, an element configured to spray a liquid, a channel forming member including a pressure chamber and an ejection port which is a port communicating with the pressure chamber and through which the liquid is ejected, and a pad array, the pad array comprising a plurality of pads electrically connected to the element, the plurality of pads being arranged along one side of the substrate, The element, the channel forming member and the pad array are arranged at the first surface of the substrate; an electrical wiring board connected to each of the plurality of pads via an electrical connection; and a sealant disposed on the first surface of the substrate and surrounding the electrical connection, wherein, in a plan view of the element substrate, the channel forming member has an opening, and the pad array is located within the opening, The manufacturing method comprises: forming a layer to be used as the channel forming member on the first surface of the substrate; and The channel forming member is formed by patterning the layer and simultaneously forming the pressure chamber and the opening.

16. The manufacturing method according to claim 15, in, In the liquid ejecting head, The channel forming member comprises: a first layer disposed on one side of the first surface and defining the pressure chamber; and a second layer disposed on a side of the first layer opposite to the substrate, the second layer having the ejection port, and The opening is arranged in the first layer, The manufacturing method comprises: forming a layer to be used as the first layer on the first surface of the substrate; and The pressure chamber and the opening are simultaneously formed by patterning a layer to be used as the first layer.

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