Manufacturing method of liquid discharge head, and liquid discharge head

Abstract

To provide a manufacturing method of a liquid discharge head and a liquid discharge head with which occurrences of failure can be restricted at a connection part of an element substrate and a flexible wiring board.SOLUTION: Temperature control is conducted using a first temperature higher than atmospheric temperature as the target temperature, with respect to an element substrate and a flexible wiring board. Then, non-conductive resin is hardened using a second temperature higher than the first temperature.SELECTED DRAWING: Figure 8

Description

[Technical Field]

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

[0002] As a technique for connecting terminals on a substrate with the wiring portion of a wiring board, Patent Document 1 describes bringing a liquid ejection chip and a wiring board close together and applying a hardenable resin around the connection portion to connect the pads together. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-66064 Summary of the Invention [Problem to be solved by the invention]

[0004] The resin around the connection portion is hardened by applying heat, but when joining the liquid ejection chip and the flexible wiring substrate, misalignment between the liquid ejection chip and the electrical connection pads on the flexible wiring substrate can occur due to factors such as the influence of the temperature when the resin hardens. In particular, in liquid ejection chips with narrower pitches for electrical connection portions due to the recent trend toward higher density of ejection ports in liquid ejection heads, misalignment raises concerns about migration. Furthermore, misalignment can also prevent proper electrical connection between the multiple terminals of the liquid ejection chip and the multiple electrical connection portions on the flexible wiring substrate.

[0005] Therefore, the present disclosure provides a method for manufacturing a liquid ejection head that can achieve appropriate electrical connection between an element substrate and a flexible wiring board, and the liquid ejection head. [Means for solving the problem]

[0006] Therefore, the method for manufacturing a liquid ejection head of the present invention is a method for manufacturing a liquid ejection head in which an element substrate having a plurality of electrode terminals and a flexible wiring substrate having a plurality of wirings with exposed conductor portions in contact with the electrode terminals are electrically connected by abutting the electrode terminals and the exposed conductor portions, and is characterized by comprising, in this order: an application process of applying a non-conductive resin to maintain the connection between the electrode terminals and the exposed conductor portions; a temperature control process of controlling the temperature of the element substrate and the flexible wiring substrate to a first temperature; an alignment process of aligning the element substrate and the flexible wiring substrate; and a connection process of contacting and pressurizing the plurality of electrode terminals and the plurality of exposed conductor portions, respectively, and connecting the plurality of electrode terminals and the plurality of exposed conductor portions by heating the non-conductive resin at a second temperature higher than the first temperature. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a liquid ejection head and a method for manufacturing the same that can suppress the occurrence of defects in the connection between the element substrate and the electrical wiring board. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a perspective view showing a liquid ejection unit. [Figure 2] FIG. 2 is an exploded perspective view of the liquid ejection unit. [Figure 3] 3A and 3B are diagrams illustrating a connection portion between an element substrate and a flexible wiring substrate. [Figure 4] 4A and 4B are diagrams showing connection portions between conductors of a flexible wiring board and electrode terminals of an element substrate. [Figure 5] FIG. 2 is a diagram showing an element substrate and a flexible wiring substrate connected together. [Figure 6] 10A and 10B are diagrams showing ideal positions when connecting an element substrate and a flexible wiring substrate. [Figure 7] 10A and 10B are diagrams illustrating positions when variations are affected when connecting an element substrate and a flexible wiring substrate. [Figure 8]10 is a flowchart showing a manufacturing process of the liquid ejection unit. [Figure 9] FIG. 10 is a top view showing a bonded state after alignment using alignment marks. [Figure 10] FIG. 2 is a top view showing an element substrate and a flexible wiring substrate. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a first embodiment of the present disclosure will be described with reference to the drawings.

[0010] 1 is a perspective view showing a liquid ejection unit 202 according to an embodiment of the present disclosure. The liquid ejection unit 202 includes an element substrate 301 including ejection ports 204 for ejecting liquid, liquid flow paths (not shown) that communicate with the ejection ports, energy generating elements provided corresponding to the ejection ports 204, and a flexible wiring board 302 electrically connected to the element substrate 301. The liquid ejection unit 202 further includes a support member 303 that supports and reinforces the element substrate 301. The element substrate 301 includes a plurality of ejection ports 204 for ejecting liquid.

[0011] The flexible wiring board 302 may be a tape for TAB (Tape Automated Bonding). In the following, the flexible wiring board 302 will be described. The support member 303 is bonded to the ejection surface side of the element substrate 301. The flexible wiring board 302 is provided with a drive circuit board 304 for driving energy generating elements (not shown) that generate energy for ejecting liquid. In this embodiment, a piezoelectric element is used as the energy generating element (drive element), but the energy generating element is not limited to a piezoelectric element and may be, for example, an electrothermal conversion element.

[0012] FIG. 2 is an exploded perspective view of the liquid ejection unit 202. Electrode terminal portions 401 are provided along the longitudinal direction (first direction) at both ends in the short side direction of the element substrate 301. Electrical connection portions 402 are provided along the short side direction at ends in the long side direction (second direction intersecting with the first direction) of the flexible wiring substrate 302. Wiring extends in the long side direction of the flexible wiring substrate 302. In the electrical connection portions 402, conductor portions (exposed conductor portions) 605 of the multiple wiring (e.g., exposed portions of the tips of wiring containing copper and nickel) (see FIG. 4 described later) are exposed in the form of pads, and function as connection portions with electrode terminals 404 of the electrode terminal portion 401 (see FIG. 4 described later). The multiple conductor portions 605 of the electrical connection portion 402 come into contact with the multiple electrode terminals 404, respectively, thereby electrically connecting the element substrate 301 and the flexible wiring substrate 302.

[0013] In this embodiment, the electrode terminals 404 in the electrode terminal sections (electrode terminal rows) 401 on both ends of the element substrate 301 are arranged at a density of 600 per inch. With two such electrode terminal rows, and each electrode terminal 404 connected to an energy generating element, the element substrate 301 is capable of recording at 1200 dpi in the longitudinal direction. The surface layer of the electrode terminals 404 is gold-plated, but other materials may be used as long as they can be stably contacted. In this embodiment, the thickness of the gold plating on the electrode terminals 404 is set to 5 μm or less. While a greater thickness is acceptable, there are concerns about increased costs and increased man-hours for the gold plating process due to the increased amount of gold used. Furthermore, since the amount of non-conductive resin 607 (see FIG. 4, described below) will increase, it is desirable to select an appropriate thickness for the gold plating as needed.

[0014] 3 is a diagram showing a connection portion between an element substrate 301 and a flexible wiring substrate 302 in this embodiment. First alignment marks 501 are provided at both ends of the element substrate 301 in the short side direction, and serve as references for alignment when connecting the flexible wiring substrate 302. In addition, second alignment marks 502 are provided at the ends of the flexible wiring substrate 302, and serve as references for alignment with the element substrate 301. By performing alignment using the first alignment marks 501 and the second alignment marks 502, it is possible to accurately align the multiple electrical connection portions 402 of the flexible wiring substrate 302 with the multiple electrode terminals 404 of the element substrate 301.

[0015] As described above, the element substrate 301 of this embodiment includes a piezoelectric element as an energy generating element for ejecting liquid. Element substrates 301 that eject liquid using a piezoelectric method tend to be provided with a relatively large number of electrode terminals 404. For this reason, in this embodiment, the distance between two adjacent electrode terminals 404 is relatively narrow. Under such circumstances, in order to accurately connect the conductor portion 605 of the electrical connection portion 402 to the electrode terminals 404, it is desirable to align the first alignment mark 501 and the second alignment mark 502 with high precision.

[0016] 4 is a diagram showing a connection portion between a conductor portion 605 of the flexible wiring board 302 and an electrode terminal 404 of the element substrate 301. The element substrate 301 includes a flow path forming substrate 601 having a flow path (not shown), an actuator substrate 602 having a surface on which piezoelectric elements (actuators) and electrode terminals 404 are provided, and a discharge port forming substrate 603 on which discharge ports 204 (see FIG. 1) are formed. When the liquid is discharged in the downward direction, the actuator substrate 602 is stacked on the discharge port forming substrate 603, and the flow path forming substrate 601 is stacked on the actuator substrate 602.

[0017] The flexible wiring board 302 includes a base portion 604 containing a resin such as polyimide, a conductor portion 605 containing copper and nickel, and a cover portion 606 containing solder resist. The element substrate 301 and the flexible wiring board 302 are connected by a non-conductive resin (Non-Conductive Paste) 607. A sealant 608 is applied (sealant application) between the element substrate 301 and the flexible wiring board 302 and on the non-conductive resin 607. The sealant 608 preferably has sufficient rigidity to protect the connection between the element substrate 301 and the flexible wiring board 302 from external forces and is also capable of suppressing corrosion caused by the ejection liquid and humidity in the environment. A preferred example of the sealant 608 is epoxy resin. However, examples of the sealant 608 are not limited to epoxy resin. The sealant 608 can contain various materials depending on the required performance.

[0018] By connecting the conductor parts 605 of the flexible wiring substrate 302 to the electrode terminals 404 of the element substrate 301, it becomes possible to supply energy and electrical signals for ejecting liquid from the flexible wiring substrate 302 to the element substrate 301. Then, the element substrate 301 becomes capable of ejecting liquid by passing electricity and communicating with the outside via the flexible wiring substrate 302.

[0019] In this embodiment, the actuator substrate 602 of the element substrate 301 includes an energy generating element (piezo element, not shown) configured with an upper electrode film (not shown), a piezoelectric layer (not shown), and a lower electrode film (not shown). When the actuator substrate 602 receives a signal supplied from the conductor portion 605 via the electrode terminal 404, it changes the volume of the piezo element and ejects droplets from the ejection ports 204. In the piezo type element substrate 301, flow paths are separated into individual channels, the number of which corresponds to the number of ejection ports 204 that eject droplets, and a piezo element that generates pressure for ejection is attached to each of the individual flow paths.

[0020] To form the ejection ports 204 at high density without changing the dimensions of the element substrate 301, it is necessary to increase the number of piezoelectric elements arranged per unit area. As the number of piezoelectric elements increases, the number of electrode terminals 404 required also increases. As the number of electrode terminals 404 increases, the number of conductors 605 on the flexible wiring substrate 302 also increases accordingly.

[0021] Fig. 5(a) is a perspective view showing the connected element substrate 301 and flexible wiring substrate 302, and Fig. 5(b) is an enlarged view showing the connected portion in Fig. 5(a). When manufacturing the liquid ejection unit 202 (see Fig. 1), there is inevitably some variation in the manufacturing of the parts themselves and in the precision of the device during connection. It is necessary to make a stable electrical connection while taking these variations into account.

[0022] In this embodiment, when connecting the conductor portion 605 (see FIG. 4) of the flexible wiring substrate 302 to the electrode terminal 404 (see FIG. 4) of the element substrate 301 as shown in FIGS. 5(a) and 5(b), it is conceivable that the position of the conductor portion 605 will vary relative to the position of the electrode terminal 404.

[0023] Fig. 6 is a cross-sectional view showing an ideal position when electrode terminal 404 of element substrate 301 is connected to conductor portion 605 of flexible wiring substrate 302. Fig. 7 is a cross-sectional view showing a positional state when electrode terminal 404 of element substrate 301 is connected to conductor portion 605 of flexible wiring substrate 302 and is affected by variations. As shown in Fig. 6, it is desirable that there is no misalignment between center Pc of electrode terminal 404 and center Fc of conductor portion 605 at all connection points. However, as mentioned above, there may be variations in the positions of center Pc of electrode terminal 404 and center Fc of conductor portion 605 due to variations in manufacturing parts, variations in device accuracy during contact, changes in environmental temperature, etc.

[0024] In the example shown in FIG. 7, a misalignment Pz occurs between the center Pc of the electrode terminal 404 and the center Fc of the conductor portion 605 at the contact position between the electrode terminal 404 located at the end and the conductor portion 605. There are several possible causes for misalignment, such as manufacturing variations in the components, alignment variations during bonding, and cure shrinkage of the non-conductive resin 607 (see FIG. 4). However, even if misalignment occurs, there is a certain contact area between the two components, and as long as the misalignment is within the range that allows for that certain area to be obtained, the electrical connection is valid and there is no problem in use. Considering the use of a thermosetting non-conductive resin, it is desirable to configure the connection width on the conductor side, which has greater variation, to be smaller than the electrode terminal side, which has smaller variation. Even if misalignment occurs, it is desirable that the variation be such that the position of the conductor portion 605 is within the width of the electrode terminal 404.

[0025] However, as the number of electrodes increases and the inter-electrode pitch narrows, it becomes increasingly difficult to suppress variations in component manufacturing, and the impact of variations becomes greater. As a result, the conductor position may not fit within the width of the electrode terminal. As mentioned above, even if the conductor width does not fit within the electrode terminal, electrical connection is possible by having a certain contact area. Therefore, taking into account variations in components and equipment, it is desirable for the contact range PFz to be in the range of 20% to 100% of the electrode terminal width PL.

[0026] On the other hand, when determining the allowable amount of misalignment, in addition to the above-mentioned viewpoint of electrical connection, it is necessary to consider migration between adjacent electrodes (distance Pm between adjacent electrodes). Although the electrodes are also protected by non-conductive resin 607 and sealing material 608 (see FIG. 4), if the distance between adjacent electrodes becomes narrower than the pressure resistance performance of each resin material, there is a concern that migration may occur depending on the usage environment. In this embodiment, the distance Pm between any conductor portion 605 and the electrode terminal 404 corresponding to the adjacent conductor portion 605 is preferably 3 μm or more.

[0027] As described above, factors that can cause misalignment between the center Pc of the electrode terminal 404 and the center Fc of the conductor portion 605 include manufacturing variations in components, alignment variations during bonding, changes in environmental temperature, etc. Therefore, in this embodiment, attention is focused on temperature changes, which are one of the factors that can cause misalignment.

[0028] If the thermal expansion coefficients of each component differ, the expansion rate of each component will also differ when the temperature changes, causing misalignment between the components before and after the temperature change. The magnitude of this misalignment is proportional to the amount of temperature change. In the manufacturing process, when looking at changes from room temperature, the temperature change when the non-conductive resin 607 (see Figure 4) hardens is large. Also, when the device is in use, the temperature change is large due to the influence of heat generated during continuous operation.

[0029] Therefore, in this embodiment, before curing the non-conductive resin 607, the element substrate 301 and the flexible wiring substrate 302 are previously adjusted to a predetermined first temperature (hereinafter referred to as temperature adjustment) within a range that does not affect the composition or shape of the non-conductive resin 607. This brings the element substrate 301 and the flexible wiring substrate 302 close to the temperature at which the non-conductive resin 607 will be cured. By adjusting the temperature to the predetermined first temperature, the element substrate 301 and the flexible wiring substrate 302 are expanded based on the predetermined first temperature. In the expanded state, the element substrate 301 and the flexible wiring substrate 302 are aligned, and then the non-conductive resin 607 is cured by heating at a second temperature that is higher than the predetermined first temperature. In the expanded state, the element substrate 301 and the flexible wiring substrate 302 are aligned, and then the non-conductive resin 607 is cured at the second temperature, thereby preventing misalignment during curing. In this embodiment, the first temperature is set to a temperature higher than room temperature.

[0030] In this way, the misalignment between the components due to the temperature change when the non-conductive resin 607 is cured is smaller than the misalignment between the components due to the temperature change from room temperature when the temperature control to the predetermined first temperature is not performed, and the misalignment between the components can be suppressed. Furthermore, by controlling the temperature, the element substrate 301 and the flexible wiring substrate 302 are aligned and connected at a temperature close to the temperature during use of the device (for example, 40°C), and therefore, the misalignment between the components due to the heat generated during continuous operation can be suppressed even when the device is in use.

[0031] 8 is a flowchart showing the manufacturing process of the liquid ejection unit 202 in this embodiment. Note that the symbol "S" in the explanation of each process means the step (process) in the flowchart.

[0032] When the manufacturing process of the liquid ejection unit 202 starts, in S801, the element substrate 301 is set on a manufacturing jig, and in S802, the flexible wiring substrate 302 is set on the manufacturing jig on which the element substrate 301 is set. In S803, non-conductive resin 607 is applied to the electrode terminals 404 of the element substrate 301 and around the electrode terminals 404.

[0033] In S804, temperature control is performed on the element substrate 301 and the flexible wiring substrate 302, with a first temperature higher than room temperature as the target temperature. By controlling the temperature, the element substrate 301 and the flexible wiring substrate 302 are made to be in a state where they are expanded more than at room temperature. Furthermore, before the flexible wiring substrate 302 is connected to the element substrate 301, a hydrophilic treatment may be performed on the surface of the flexible wiring substrate 302 that faces the element substrate 301. The hydrophilic treatment improves the wettability of the surface, making it easier for the non-conductive resin 607 to wet and spread, and preventing the non-conductive resin 607 from dripping and flowing into the discharge port 204. Note that the treatment to be performed is not limited to the hydrophilic treatment, as long as it can prevent the non-conductive resin 607 from dripping.

[0034] In S805, the element substrate 301 and the flexible wiring substrate 302 are aligned. The alignment is performed using the first alignment mark 501 and the second alignment mark 502. In S806, the flexible wiring substrate 302 is pressed against the element substrate 301. Specifically, the flexible wiring substrate 302 is pressed against the surface of the element substrate 301 on which the electrode terminals 404 are provided, while keeping the flexible wiring substrate 302 substantially parallel to the surface, using a tool.

[0035] In S807, the non-conductive resin 607 is cured at a second temperature higher than the first temperature. Specifically, a predetermined temperature is applied to the non-conductive resin 607 for a predetermined time in accordance with the curing characteristics of the non-conductive resin 607 being used. This causes a curing contraction force to appear in the non-conductive resin 607, causing the non-conductive resin 607 to cure. As the non-conductive resin 607 cures, the connection between the element substrate 301 and the flexible wiring substrate 302 is maintained.

[0036] In S808, after the predetermined time set in step S807 has elapsed, the pressure is released and the application of heat is stopped. Active cooling may be performed, but it is preferable to set this in consideration of the impact on the components. In S809, a sealant 608 is applied to the connected flexible wiring board 302 and hardened. After this process, the liquid ejection unit 202 is completed.

[0037] 9(a) is a top view showing a state before bonding in which the element substrate 301 and the flexible wiring substrate 302 are aligned using the first alignment mark 501 and the second alignment mark 502 while being temperature-controlled at a first temperature. FIG. 9(b) is a top view showing the element substrate 301 and the flexible wiring substrate 302 at room temperature after connection in this embodiment.

[0038] In this embodiment, in the state before bonding as shown in Fig. 9(a), the electrode terminals 404 and the conductor portions 605 are aligned by aligning the element substrate 301 and the flexible wiring substrate 302 using the first alignment mark 501 and the second alignment mark 502. From the state shown in Fig. 9(a), the connection between the element substrate 301 and the flexible wiring substrate 302 is completed by curing the non-conductive resin 607 at a second temperature. Fig. 9(b) shows the state after the element substrate 301 and the flexible wiring substrate 302 have been connected and have returned to room temperature.

[0039] 9(b), region 900 is a constrained region in which the electrode terminals 404 and the conductor portion 605 are constrained by the hardened non-conductive resin 607. Region 901 corresponds to the portion indicated by reference numeral 400 in FIG. 4, and is an unconstrained region in which the non-conductive resin 607 is hardened but the wiring of the flexible wiring substrate 302 is not constrained. Because region 901 is an unconstrained region, when the temperature returns to room temperature after connection is complete, region 901 also shrinks along with the contraction of the flexible wiring substrate 302, as shown in FIG. 9(b). Because region 900 is a constrained region, it does not shrink even when returned to room temperature. Therefore, the length TPcon in the arrangement direction of the row in which the electrode terminals 404 of the element substrate 301 are lined up is longer than the length TPdiscon in the arrangement direction of the wiring (exposed conductor portion row) in the electrical connection portion 402 of the flexible wiring substrate 302.

[0040] In this way, the temperatures of the element substrate 301 and the flexible wiring substrate 302 are adjusted to a first temperature as a target temperature, and then the non-conductive resin 607 is cured at a second temperature higher than the first temperature. This makes it possible to provide a liquid ejection head manufacturing method and a liquid ejection head that are capable of achieving appropriate electrical connection between the element substrate and the electrical wiring substrate.

[0041] (Second embodiment) The second embodiment of the present invention will be described below with reference to the drawings. Note that the basic configuration of this embodiment is the same as that of the first embodiment, so only the characteristic configuration will be described below.

[0042] Fig. 10(a) is a top view showing the connected element substrate 301 and flexible wiring substrate 302 in this embodiment, Fig. 10(b) is an enlarged view showing the connected portion in Fig. 10(a), Fig. 10(c) is a top view showing the ideal positional relationship between the element substrate 301 and flexible wiring substrate 302, and Fig. 10(d) is a top view showing the positional relationship between the element substrate 301 and flexible wiring substrate 302 at room temperature in this embodiment.

[0043] 10(d), in this embodiment, the total pitch TPc, which is the distance between the first alignment marks 501 on the element substrate 301 at room temperature, is set longer than the total electrode pitch TPf, which is the distance between the second alignment marks 502 on the flexible wiring substrate 302. Note that there are two types of alignment marks: + shaped and O shaped, but here the total pitch is defined using + shaped alignment marks.

[0044] In this embodiment, when connecting the conductor portion 605 of the flexible wiring substrate 302 to the electrode terminal 404 of the element substrate 301 as shown in Figures 10(a) and 10(b), temperature control is performed with the first temperature as the target temperature, as described in the first embodiment.

[0045] Regarding the element substrate 301 and the flexible wiring substrate 302, the element substrate 301 is mainly made of Si and has a small thermal expansion coefficient. On the other hand, the flexible wiring substrate 302 is made of a material such as polyimide, which has a large volume and is therefore affected by the physical properties of polyimide. In general, the thermal expansion coefficient of polyimide is larger than that of Si.

[0046] 10(c), even if the total pitch TPc and the electrode portion total pitch TPf are the same at room temperature, performing temperature control with the first temperature as the target temperature will cause the flexible wiring substrate 302 to expand more than the element substrate 301. As a result, it is conceivable that the electrode portion total pitch TPf will become larger than the total pitch TPc. If the electrode portion total pitch TPf becomes larger than the total pitch TPc, there is a risk that the positions of the electrical connection portions 402 of the flexible wiring substrate 302 will be misaligned with respect to the electrode terminals 404 of the element substrate 301, preventing proper electrical connection.

[0047] 10(d), in this embodiment, the total pitch TPc, which is the distance between the first alignment marks on the element substrate 301 at room temperature, is made longer than the total pitch TPf of the electrode portions, which is the distance between the second alignment marks on the flexible wiring substrate 302. In this way, by performing temperature control with the first temperature as the target temperature, the total pitch TPc and the total pitch TPf of the electrode portions become aligned, enabling stable electrical connection.

[0048] This makes it possible to provide a liquid ejection head and a manufacturing method thereof that enable appropriate electrical connection to be made at the connection portion between the element substrate and the electrical wiring board.

[0049] (Third embodiment) The third embodiment of the present invention will be described below. Note that the basic configuration of this embodiment is the same as that of the first embodiment, so the following will describe the characteristic configuration.

[0050] In each of the above embodiments, the temperature of the element substrate 301 and the flexible wiring substrate 302 is controlled with a first temperature as the target temperature. In this embodiment, the target temperatures are different for the temperature control of the element substrate 301 and the temperature control of the flexible wiring substrate 302. Specifically, the target temperature of the element substrate 301, which has a small thermal expansion coefficient, is set higher than the target temperature of the flexible wiring substrate 302, which has a large thermal expansion coefficient. It is desirable to set both target temperatures within a range that does not affect the composition or shape of the non-conductive resin 607.

[0051] In this way, different target temperatures are set for temperature control of the element substrate 301 and temperature control of the flexible wiring substrate 302. This makes it possible to provide a liquid ejection head and a manufacturing method thereof that enable appropriate electrical connection at the connection portion between the element substrate and the electrical wiring substrate.

[0052] (Other embodiments) Although examples to which the technology of the present disclosure can be applied have been described above, the technical scope of the present disclosure is not limited to the above examples. The first, second, third, and fourth embodiments may be combined as appropriate as possible.

[0053] In the above embodiments, the manufacturing process of the liquid ejection unit 202 has been described, but the order in which the steps are performed is not limited as long as it is possible to manufacture the liquid ejection unit 202. The steps in the manufacturing process of the liquid ejection unit 202 may be appropriately rearranged in order or may be performed simultaneously.

[0054] The liquid described in the above embodiment may be any of various recording liquids, including ink and treatment liquids used for the purposes of improving the fixation of ink on a recording medium, reducing uneven gloss, and improving abrasion resistance.

[0055] In the above embodiments, the electrode terminals 404 are provided along both sides of the element substrate, but the electrode terminals 404 may be provided along all sides of the element substrate 301. In this case, the flexible wiring substrate 302 is drawn out from all ends of the element substrate 301. Therefore, compared to the above embodiments, the number of electrodes can be increased, and the density of the multiple ejection ports formed can be increased. By increasing the density of the ejection ports, it becomes possible to maintain high printing quality even during high-speed printing.

[0056] In the above embodiments, the energy generating means is described as a piezoelectric element, but examples of the energy generating means are not limited to piezoelectric elements as long as they can impart the energy necessary for ejection to the liquid. Another example of the energy generating means is an electrothermal converter. For example, a heater as an electrothermal converter may be used to apply heat to the liquid to generate bubbles, thereby ejecting the liquid from the ejection opening. The technology disclosed herein can also be applied to such so-called thermal liquid ejection units.

[0057] In the above-described embodiments, the non-conductive resin 607 is applied to the element substrate 301, but the flexible wiring substrate 302 to which the non-conductive resin 607 is applied may be connected to an element substrate 301 to which the non-conductive resin 607 is not applied. In other words, whether the non-conductive resin 607 is applied to the element substrate 301 or the flexible wiring substrate 302 can be appropriately selected depending on the configuration of the liquid ejection device.

[0058] In each of the above embodiments, the element substrate 301 and the flexible wiring substrate 302 are connected by the non-conductive resin 607. However, the element substrate 301 and the flexible wiring substrate 302 may be connected by an anisotropic conductive resin film (ACF). It is also possible to connect the element substrate 301 and the flexible wiring substrate 302 by a method such as a metal bonding method using ultrasonic waves, heat, or the like, using gold bumps formed on the electrodes.

[0059] In the above embodiments, the description is based on the assumption that an electrode terminal is connected to a wiring. However, the technology disclosed herein is not limited to the connection between an electrode terminal and a wiring, and can be applied to a technology for connecting terminals to each other.

[0060] The liquid ejection unit 202 described in each of the above embodiments can be mounted on a liquid ejection apparatus and used as a liquid ejection section in the liquid ejection apparatus.

[0061] The disclosure of this embodiment includes the following methods and configurations.

[0062] (Method 1) A method for manufacturing a liquid ejection head, in which an element substrate having a plurality of electrode terminals and a flexible wiring substrate having a plurality of wirings each having an exposed conductor portion in contact with the electrode terminals are electrically connected by abutting the electrode terminals with the exposed conductor portion, a coating step of coating a non-conductive resin to maintain connection between the electrode terminal and the exposed conductor portion; a temperature control step of controlling the temperatures of the element substrate and the flexible wiring substrate to a first temperature; an alignment step of aligning the element substrate and the flexible wiring substrate; a connecting step of connecting the electrode terminals and the exposed conductor portions, respectively, by bringing the electrode terminals and the exposed conductor portions into contact with each other and applying pressure to the electrode terminals and the exposed conductor portions, and heating the non-conductive resin at a second temperature higher than the first temperature; A method for manufacturing a liquid ejection head, comprising the steps of:

[0063] (Method 2) The method for manufacturing a liquid ejection head according to Method 1, wherein the temperature is adjusted to the first temperature, which is higher than room temperature, in the temperature adjustment step.

[0064] (Method 3) The method for manufacturing a liquid ejection head described in Method 1 or 2 further includes a sealing material application process of applying a sealing material that covers the non-conductive resin between the element substrate and the flexible wiring substrate after connecting the electrode terminal and the exposed conductor portion.

[0065] (Method 4) 4. The method for manufacturing a liquid ejection head according to any one of Methods 1 to 3, wherein a wiring board containing a resin is used as the flexible wiring board.

[0066] (Method 5) The method for producing a liquid ejection head according to method 4, wherein a wiring substrate containing polyimide is used as the wiring substrate.

[0067] (Method 6) the element substrate has a plurality of ejection ports for ejecting liquid and a plurality of drive elements for ejecting liquid from the ejection ports; 5. The method for manufacturing a liquid ejection head according to any one of Methods 1 to 4, wherein the plurality of electrode terminals are electrically connected to the plurality of drive elements, respectively.

[0068] (Method 7) the element substrate has an electrode terminal row in which the plurality of electrode terminals are arranged, the flexible wiring board has an exposed conductor portion row in which the plurality of exposed conductor portions are arranged, 7. The method for manufacturing a liquid ejection head according to any one of Methods 1 to 6, wherein the alignment step aligns the electrode terminal array with the exposed conductor portion array.

[0069] (Method 8) A method for manufacturing a liquid ejection head according to method 7, in which the alignment process aligns the electrode terminal array with the exposed conductor portion array using alignment marks provided on the element substrate and the electrode terminal array, respectively.

[0070] (Method 9) The method for manufacturing a liquid ejection head according to Method 7 or 8, wherein the length of the portion where the exposed conductor portion and the electrode terminal abut in the arrangement direction of the electrode terminals in the electrode terminal row is in the range of 20% to 100% of the length in the arrangement direction of the electrode terminals.

[0071] (Method 10) 10. The method for manufacturing a liquid ejection head according to any one of Methods 7 to 9, wherein the electrode terminal array is provided on a side of the element substrate.

[0072] (Method 11) A method for manufacturing a liquid ejection head described in any one of methods 7 to 10, wherein the element substrate has the electrode terminal array on each of two opposing sides, and in the alignment process, the flexible wiring substrate is connected to each of the electrode terminal arrays.

[0073] (Method 12) 7. The method for manufacturing a liquid ejection head according to Method 6, wherein the driving element is a piezoelectric element.

[0074] (Configuration 1) a substrate on which a plurality of electrode terminals are arranged in a first direction; a flexible wiring substrate on which a plurality of wirings extending in a second direction intersecting the first direction are arranged in the first direction; an electrical connection portion in which the plurality of electrode terminals and the tips of the plurality of wirings are electrically connected and covered with a non-conductive resin; A liquid ejection head comprising: A liquid ejection head characterized in that the length by which the multiple wirings are arranged in the first direction in the electrical connection portion is longer than the length by which the multiple wirings are arranged in the first direction in an area adjacent to the electrical connection portion in the second direction.

[0075] (Configuration 2) The liquid ejection head according to configuration 1, wherein the distance in the first direction between the tip of any one of the plurality of wirings and the electrode terminal to which the tip of the wiring adjacent to that wiring is connected is 3 μm or more. [Explanation of symbols]

[0076] 202 Liquid Discharge Unit 301 Element substrate 302 Flexible wiring board 401 Electrode terminal section 402 Electrical Connections 501 First alignment mark 502 Second Alignment Mark 607 Non-conductive resin

Claims

1. A method for manufacturing a liquid ejection head, in which an element substrate having a plurality of electrode terminals and a flexible wiring substrate having a plurality of wirings each having an exposed conductor portion in contact with the electrode terminals are electrically connected by abutting the electrode terminals with the exposed conductor portion, a coating step of coating a non-conductive resin to maintain connection between the electrode terminal and the exposed conductor portion; a temperature control step of controlling the temperatures of the element substrate and the flexible wiring substrate to a first temperature; an alignment step of aligning the element substrate and the flexible wiring substrate; a connecting step of connecting the electrode terminals and the exposed conductor portions, respectively, by bringing the electrode terminals and the exposed conductor portions into contact with each other and applying pressure to the exposed conductor portions, and heating the non-conductive resin at a second temperature higher than the first temperature; A method for manufacturing a liquid ejection head, comprising the steps of:

2. The method for manufacturing a liquid ejection head according to claim 1 , wherein the temperature is adjusted to the first temperature, which is higher than room temperature, in the temperature adjustment step.

3. 2. The method for manufacturing a liquid ejection head according to claim 1, further comprising a sealing material application process for applying a sealing material to cover the non-conductive resin between the element substrate and the flexible wiring substrate after connecting the electrode terminal and the exposed conductor portion.

4. The method for manufacturing a liquid ejection head according to claim 1 , wherein the flexible wiring board is a wiring board containing a resin.

5. The method for manufacturing a liquid ejection head according to claim 4, wherein a wiring substrate containing polyimide is used as the wiring substrate.

6. the element substrate has a plurality of ejection ports for ejecting liquid and a plurality of drive elements for ejecting liquid from the ejection ports; The method for manufacturing a liquid ejection head according to claim 1 , wherein the plurality of electrode terminals are electrically connected to the plurality of drive elements, respectively.

7. the element substrate has an electrode terminal row in which the plurality of electrode terminals are arranged, the flexible wiring board has an exposed conductor portion row in which the plurality of exposed conductor portions are arranged, The method for manufacturing a liquid ejection head according to claim 1 , wherein the alignment step aligns the electrode terminal array with the exposed conductor array.

8. The method for manufacturing a liquid ejection head according to claim 7 , wherein the alignment step aligns the electrode terminal array with the exposed conductor portion array using alignment marks provided on the element substrate and the electrode terminal array, respectively.

9. 8. A method for manufacturing a liquid ejection head according to claim 7, wherein the length of the portion where the exposed conductor portion and the electrode terminal abut in the arrangement direction of the electrode terminals in the electrode terminal row is in the range of 20% to 100% of the length in the arrangement direction of the electrode terminals.

10. The method for manufacturing a liquid ejection head according to claim 7 , wherein the electrode terminal array is provided on a side of the element substrate.

11. The method for manufacturing a liquid ejection head according to claim 7 , wherein the element substrate has the electrode terminal arrays on each of two opposing sides, and the flexible wiring substrate is connected to each of the electrode terminal arrays in the alignment process.

12. The method for manufacturing a liquid ejection head according to claim 6, wherein the driving element is a piezoelectric element.

13. a substrate on which a plurality of electrode terminals are arranged in a first direction; a flexible wiring substrate on which a plurality of wirings extending in a second direction intersecting the first direction are arranged in the first direction; an electrical connection portion in which the plurality of electrode terminals and the tips of the plurality of wirings are electrically connected and covered with a non-conductive resin; A liquid ejection head comprising: A liquid ejection head characterized in that the length by which the multiple wirings are arranged in the first direction in the electrical connection portion is longer than the length by which the multiple wirings are arranged in the first direction in the region adjacent to the electrical connection portion in the second direction.

14. 14. The liquid ejection head according to claim 13, wherein the distance in the first direction between the tip of any one of the plurality of wirings and the electrode terminal to which the tip of the wiring adjacent to that wiring is connected is 3 [mu]m or more.

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