Liquid ejection unit and manufacturing method thereof

Abstract

To provide a liquid discharge unit which secures reliability in an electric connection part between a recording element substrate and an electric wiring board.SOLUTION: A liquid discharge unit includes: a recording element substrate having a discharge port for discharging a liquid, an energy generating element for generating energy for discharging the liquid from the discharge port and an electrode terminal electrically connected to the energy generating element; an electric wiring board having a relay terminal electrically connected to the electrode terminal; an electric connection member having a first connection end part connected to the electrode terminal of the recording element substrate, a second connection end part connected to the relay terminal of the electric wiring board and a connecting part configured to connect between the first connection end part and the second connection end part; and a sealing agent structured so as to cover an electric connection part including at least the electric connection member, the electrode terminal and the relay terminal, wherein the electric connection member has at least one bending point in the connection part.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] An example of an application of the liquid ejection unit is an inkjet recording device. The liquid ejection unit used in the inkjet recording device is called an inkjet head. The inkjet head is used to eject ink as a liquid onto a recording medium. To this end, the inkjet head has a recording element substrate equipped with energy generating elements configured to generate energy for ejecting ink. At this time, in order to drive the energy generating elements, the recording element substrate needs to receive a supply of power from the outside via an electric wiring substrate or the like. Therefore, the recording element substrate on which the energy generating elements are provided is provided with electrode terminals. In addition, the recording element substrate is electrically connected to an electric wiring substrate such as a flexible printed circuit (FPC) or a tape automated bonding (TAB).

[0003] Patent Document 1 discloses that in a liquid ejection unit, the lead portion of the electric wiring board and the electrode terminal of the recording element board are electrically connected by wire bonding. Patent Document 1 further discloses that the electrical connection portion including the relay terminal provided at the end of the lead portion of the electric wiring board, the electrode terminal of the recording element board, and the wire connecting them is protected by a sealant. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 9,950,511 Summary of the Invention [Problem to be solved by the invention]

[0005] If the wire has a normal loop shape that is bent with a continuous curvature over its entire length, the following problem occurs. That is, after wire bonding, the wire is elastically deformed with the first bonding portion on the electrode terminal as a fulcrum. As a result, the electric wiring board is lifted by the reaction force of the wire trying to return to a straight shape, and a gap may occur between the recording element board and the electric wiring board. If a sealant is then applied, the sealant will flow out of the gap, which may cause unstable protection for the electrode connection and reduce the reliability of the electrical connection.

[0006] The present disclosure has been made in consideration of the above problems, and aims to provide a liquid ejection unit in which reliability is ensured in the electrical connection between a recording element substrate and an electrical wiring substrate, and a manufacturing method thereof. [Means for solving the problem]

[0007] One embodiment of the present disclosure includes a recording element substrate having an ejection port for ejecting a liquid, an energy generating element for generating energy for ejecting the liquid from the ejection port, and an electrode terminal electrically connected to the energy generating element; an electric wiring substrate having a relay terminal for electrically connecting to the electrode terminal and joined to the recording element substrate; and a relay terminal for connecting the electrode terminal of the recording element substrate to the relay terminal of the electric wiring substrate. Wire the recording element substrate has a plurality of the energy generating elements and a plurality of the electrode terminals, each of the energy generating elements and each of the electrode terminals being electrically connected to each other; the electric wiring substrate has a plurality of the relay terminals corresponding to the plurality of the electrode terminals, and the electrode terminals and each of the relay terminals are electrically connected to each other; Wire and a plurality of said relay terminals are provided. The child , for the adjacent relay terminals, Wire In the extension direction of Alternately The plurality of said Wire The plurality of Wire In the arrangement direction of Wire and the first Wire a second electrode having a length in the extending direction greater than that of the first electrode; Wire and a liquid ejection unit having the liquid ejection unit and the liquid ejection unit arranged so that the liquid ejection unit is in contact with the recording element substrate. By wire bonding, A connecting step of connecting at least the Wire and a covering step of covering the electrical connection portion including the electrode terminal and the relay terminal, wherein in the connecting step, Wire to have at least one plastically deformed bending point and adjacent to said second Wire In contrast, the method for manufacturing a liquid ejection unit is shaped so that the maximum height from the surface of the open portion on which the electrode terminals of the recording element substrate are arranged is increased. Effect of the Invention

[0008] According to the present disclosure, it is possible to obtain a liquid ejection unit in which the reliability of the electrical connection between the recording element substrate and the electrical wiring substrate is ensured. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view illustrating an entire liquid ejection unit according to a first embodiment of the present disclosure. [Diagram 2] 1 is an exploded perspective view showing an entire liquid ejection unit according to a first embodiment of the present disclosure. [Diagram 3] 2 is a partial cross-sectional view showing a main portion of a recording element substrate included in the liquid ejection unit according to the first embodiment of the present disclosure. FIG. [Figure 4] 3 is a partial cross-sectional view showing a part of a recording element substrate included in the liquid ejection unit according to the first embodiment of the present disclosure, a part of an electric wiring substrate connected thereto, and a sealant. FIG. [Diagram 5]FIG. 2 is a partial plan view showing an electrical connection portion and its periphery of the liquid ejection unit according to the first to fifth embodiments of the present disclosure. [Figure 6] 11 is a partial cross-sectional view showing an electrical connection portion of a liquid ejection unit according to a comparative example before being sealed with a sealant. [Figure 7] FIG. 11 is a partial cross-sectional view for explaining a reaction force generated in a wire that is an electrical connection member in a comparative example. [Figure 8] 10 is a partial cross-sectional view for explaining how an electric wiring board is displaced by a reaction force generated in a wire that is an electrical connection member in a comparative example. FIG. [Figure 9] FIG. 11 is a partial cross-sectional view for explaining that protection of electrical connections by a sealant becomes insufficient due to displacement of an electrical wiring board in a comparative example. [Figure 10] 4 is a partial cross-sectional view showing an electrical connection portion and its periphery before being sealed with a sealant of the liquid ejection unit according to the first embodiment of the present disclosure. FIG. [Figure 11] 4 is a partial cross-sectional view showing an electrical connection portion sealed with a sealant and its surroundings of the liquid ejection unit according to the first embodiment of the present disclosure. FIG. [Figure 12] 6A to 6C are diagrams illustrating a method for manufacturing the liquid ejection unit according to the embodiment of the present disclosure. [Figure 13] FIG. 11 is a perspective view showing an entire liquid ejection unit according to a second embodiment of the present disclosure. [Figure 14] 13 is a partial perspective view showing an electrical connection section and its periphery of a liquid discharge unit according to a second embodiment of the present disclosure. FIG. [Figure 15] FIG. 11 is a partial perspective view showing an electrical connection section and its periphery of a liquid discharge unit according to a third embodiment of the present disclosure. [Figure 16] 13 is a partial perspective view showing an electrical connection section and its periphery of a liquid discharge unit according to a fourth embodiment of the present disclosure. FIG. [Figure 17] 13 is a partial perspective view showing an electrical connection section and its periphery of a liquid ejection unit according to a fifth embodiment of the present disclosure. FIG. [Figure 18]13 is a partial plan view showing an electrical connection portion and its periphery of a liquid ejection unit according to a sixth embodiment and a seventh embodiment of the present disclosure. [Figure 19] 13 is a partial perspective view showing an electrical connection section and its periphery of a liquid ejection unit according to a sixth embodiment of the present disclosure. FIG. [Figure 20] 13 is a partial perspective view showing an electrical connection section and its periphery of a liquid discharge unit according to a seventh embodiment of the present disclosure. FIG. [Figure 21] 13 is a table showing various combinations of shapes of electrical connection members of a liquid discharge unit according to an eighth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Next, an embodiment of the present disclosure will be described with reference to the drawings. A liquid ejection unit based on the present disclosure has at least a recording element substrate and an electric wiring substrate. The recording element substrate includes an ejection port for ejecting liquid, an energy generating element for generating energy for ejecting liquid from the ejection port, and an electrode terminal electrically connected to the energy generating element. The electric wiring substrate is electrically connected to the electrode terminal of the recording element substrate. Several embodiments of such a liquid ejection unit based on the present disclosure will be described below, but these embodiments do not limit the scope of the present invention.

[0011] In addition, the energy generating element in each embodiment may be, for example, one that employs a thermal system or one that utilizes a piezoelectric system, but the present invention is not limited to this. The thermal system uses a liquid ejection unit that uses an electrothermal converter to apply heat to the liquid to generate bubbles and eject the liquid from the ejection port. The piezoelectric system uses a liquid ejection unit that uses a piezoelectric element (piezo element) that changes volume when a voltage is applied, and ejects the liquid by utilizing the pressure caused by the volume change.

[0012] In particular, the present disclosure can be suitably used in a piezoelectric liquid ejection unit that uses a piezoelectric element as an energy generating element. In a piezoelectric liquid ejection unit, the number of flow paths is divided individually by the number of ejection ports that eject droplets, and a piezoelectric element that generates pressure for ejection is attached to each of the individual flow paths. If it is attempted to arrange the ejection ports at high density without changing the dimensions of the recording element substrate, it is necessary to increase the number of piezoelectric elements, and the number of electrode terminals will also increase accordingly. If the number of electrode terminals increases, the number of wires will also increase accordingly, and the reaction force due to the elastic deformation of the wires will also increase. According to the present disclosure, even when the number of electrode terminals is large, high reliability can be obtained in the electrical connection between the recording element substrate and the electrical wiring substrate.

[0013] (First embodiment) 1 to 5 are diagrams showing a liquid ejection unit according to a first embodiment of the present disclosure. FIG. 1 is a perspective view showing the entire liquid ejection unit 101. FIG. 2 is an exploded perspective view showing the liquid ejection unit 101 in a state in which the recording element substrate 102 and the electric wiring substrate 103 are separated. FIG. 3 is a partial cross-sectional view taken along line III-III in FIG. 2, showing a main part of the recording element substrate 102. FIG. 4 is a partial cross-sectional view taken along line IV-IV in FIG. 1, showing a main part of the liquid ejection unit 101 in a state in which the electric wiring substrate 103 is connected to the recording element substrate 102. FIG. 5 is a partial plan view showing an electrical connection portion between the recording element substrate 102 and the electric wiring substrate 103 and the periphery thereof. For ease of understanding, the sealant 104 is not shown in FIG. 5.

[0014] As shown in FIG. 1, the liquid ejection unit 101 includes a recording element substrate 102 and an electric wiring substrate 103 connected to the recording element substrate 102. A plurality of ejection ports 109 for ejecting liquid are arranged on one surface (the upper surface in the figure) of the recording element substrate 102. As shown in FIG. 2, the electric wiring substrate 103 is a thin, flexible, elongated member made of, for example, an FPC or a TAB, and is used to supply power and signals to the recording element substrate 102 from the main body of the liquid ejection device on which the liquid ejection unit is mounted. Relay terminals 110 are formed on the end of the electric wiring substrate 103 on the recording element substrate 102 side in the longitudinal direction. In each of the relay terminals 110, a conductor is exposed in the form of a pad. As will be described later, the relay terminals 110 are connected to the electrode terminals 7 of the recording element substrate 102 via wires which are the electrical connection members 106. A plurality of connection terminals 135 are formed on the other end of the electric wiring substrate 103 in the longitudinal direction, and these are electrically connected to the circuit of the liquid ejection device. At each connection terminal 135, a conductor is exposed in the form of a pad.

[0015] Here, the electric wiring board 103 can be bonded to the open surface 125 (see FIG. 3) having the electrode terminals 107 of the recording element substrate 102 by using, for example, an adhesive. However, if an adhesive is used, the material cost increases, and it becomes necessary to introduce equipment for applying and curing the adhesive, which results in associated costs. Furthermore, the number of steps increases accordingly, and variable costs and processing costs also increase. Therefore, in this embodiment, the electric wiring board 103 is not bonded to the open surface 125 having the electrode terminals 107 of the recording element substrate 102 by using an adhesive. In this embodiment, the electric wiring board 103 is fixed to the open surface 125 having the electrode terminals 107 of the recording element substrate 102 by using a sealant 104 that also has a function of protecting the electrical connection portion. At that time, a certain amount of the sealant 104 also flows into the portion of the recording element substrate 102 on which the electric wiring board 103 is placed and hardens. Therefore, in this embodiment, the sealant 104 has both the function of protecting the electrical connections and the function of fixing the electrical wiring board 103 to the open surface 125 having the electrode terminals 107 of the recording element board 102 .

[0016] As shown in FIG. 5, the multiple relay terminals 110 and the multiple connection terminals 135 are electrically connected one-to-one by multiple lead portions 136 formed on a conductor layer inside the electric wiring board 103 .

[0017] 3, the recording element substrate 102 includes an ejection port forming substrate 121 in which the ejection ports 109 are mainly formed, an actuator substrate 122 having the energy generating elements 108 and electrodes 133, and a flow path forming substrate 123. These substrates 121, 122, and 123 are laminated.

[0018] A flow channel 113 is formed in the flow channel forming substrate 123, which communicates with an individual flow channel 134 formed in the actuator substrate 122. The side of the flow channel forming substrate 123 above the actuator substrate 122 is open, and an electrode terminal 107 is provided on a surface 125 of the open portion. The actuator substrate 122 is further provided with an energy generating element 108 including an upper electrode film 130, a piezoelectric layer 131, and a lower electrode film 132. The volume of the energy generating element 108 changes in response to a signal input from the outside via the electrode 133 and the electrode terminal 107, causing liquid to be ejected from the ejection port 109.

[0019] Next, the connection between the recording element substrate 102 and the electric wiring substrate 103 will be described with reference to FIG. 4. The recording element substrate 102 and the electric wiring substrate 103 are electrically connected by connecting the electrode terminal 107 of the recording element substrate 102 and the relay terminal 110 of the electric wiring substrate 103 using the electric connection member 106. As already described, the part including the electrode terminal 107, the relay terminal 110, and the electric connection member 106 is called the electric connection part. The electric connection member 106 is usually a conductor wire for connection (i.e., a bonding wire), and is joined to each of the electrode terminal 107 and the relay terminal 110 by a wire bonding technique. The electric connection member 106 is not limited to a gold wire, and may be, for example, a metal mainly composed of any one of gold, copper, aluminum, and silver, or an alloy containing two or more of these metals. In this embodiment, the electric connection member 106 is, for example, a gold wire. The entire electric connection part is sealed and protected by a sealant 104. As shown in Fig. 4 and Fig. 5, the sealant 104 is distributed in the longitudinal direction of the electric wiring board 103 in a range from a position close to the relay terminal 110 of the lead portion 136 to a side surface of the flow path forming substrate 123. The sealant 104 is distributed in a range that completely covers the electric connection member 106 in the height direction of the recording element board 102 or the height direction (i.e., thickness direction) of the electric wiring board 103. It is preferable that the sealant 104 has rigidity for protecting the electric connection part from external forces and has a function of suppressing corrosion of the electric connection part due to the liquid for ejection or moisture in the environment. For this reason, a material such as an epoxy resin is preferably used for the sealant 104, but an appropriate material can be used for the sealant 104 depending on the performance required for the sealant 104.

[0020] To reiterate, in this embodiment, the electrode terminal 107 and the relay terminal 110 are connected by wire bonding using the electrical connection member 106. When performing wire bonding, a bonding tool (not shown) is used, and heat, pressure, ultrasonic waves, etc. are applied while the electrical connection member 106 is brought into contact with the electrode terminal 107 and the relay terminal 110. As a result, one end of the electrical connection member 106 is bonded to the electrode terminal 107, thereby providing a first bonding point, and the other end is bonded to the relay terminal 110, thereby providing a second bonding point. Then, the electrical connection between the electrode terminal 107 and the relay terminal 110 is completed. Generally, a wire bonder is used for wire bonding, and the wire shape is formed by variously adjusting the trajectory of a bonding tool called a capillary.

[0021] As a comparative example, FIG. 6 shows a general wire shape that does not depend on this embodiment. At this time, in the wire shape shown in Patent Document 1, as shown in FIG. 6, the wire has a shape that does not have a clear bend. In the case of such a shape, after electrical connection, the wire is bent in the elastic deformation region over the entire length with the first bonding point as a fulcrum, and a reaction force as shown in FIG. 7 is generated in the wire. As a result, a force that lifts the electric wiring board 303 as shown in FIG. 8 acts, and a gap may be generated between the recording element board 302 and the electric wiring board 303. If the sealant 304 is applied in such a state that a gap is generated, the sealant 304 flows out from the gap between the recording element board 302 and the electric wiring board 303 to below the electric wiring board 303 as shown in FIG. 9. In this case, there is a risk that the wire cannot be properly covered with the sealant 304, and there is a concern about ensuring electrical reliability. If the height of the wire loop shape is low, if the wire length is short, or if the wire has a taut shape, there is a greater possibility that the electrical wiring board 303 will be lifted up, and there is a greater risk that the wire will not be properly coated with the sealant 304.

[0022] On the other hand, in this embodiment, as shown in FIG. 10, the first bent portion 106c and the second bent portion 106d are provided in the loop shape of the electrical connection member 106 spanning from the first bonding portion 106a to the second bonding portion 106b. In addition, a vertical portion 106g is provided between the first bonding portion 106a and the first bent portion 106c. A horizontal portion 106e is provided between the first bent portion 106c and the second bent portion 106d. A hypotenuse portion 106f is provided from the second bent portion 106d to the second bonding portion 106b. The vertical portion is perpendicular to the open portion surface 125. The horizontal portion is approximately parallel to the open portion surface 125 and is also approximately parallel to the surface on which the relay terminal 110 of the electrical wiring board 103 is disposed. The first bent portion 106c and the second bent portion 106d are plastically deformed near the yield point. In other words, the first bent portion 106c and the second bent portion 106d are bent with a curvature such that the magnitude of strain falls within the range from the upper yield point to the yield plateau in the relationship between the strain and internal stress of the electrical connection member 106. In such a case, the electrical connection member 106 undergoes plastic deformation and maintains the shape shown in FIG. 10 even without being restricted by an external force.

[0023] There is a possibility that the second bent portion 106d will not be plastically deformed. However, even in such a case, the elastic deformation area becomes the oblique side portion 106f from the second bent portion 106d toward the second bonding portion 106b, and the reaction force acting on the electric wiring board 103 is reduced, and the force acting to lift the electric wiring board 103 becomes small. Therefore, as shown in FIG. 11, the gap between the recording element board 102 and the electric wiring board 103 can be reduced. When the second bent portion 106d is plastically deformed, as shown in FIG. 4, almost no gap is generated between the recording element board 102 and the electric wiring board 103, and the sealant 104 only leaks out very slightly to the back surface of the electric wiring board 103. Even if the second bent portion 106d is not plastically deformed, the force acting to lift the electric wiring board 103 is small, so that only a small gap is generated between the recording element board 102 and the electric wiring board 103, as shown in FIG. 11. Therefore, the sealant 104 only leaks slightly onto the rear surface of the electric wiring board 103. This makes it possible to prevent a part of the electrical connection member 106 from being exposed from the sealant 104.

[0024] At this time, the length of the horizontal portion is preferably 50 μm or more and 500 μm or less. Also, the angle (wire oblique side angle) θ of the oblique side portion 106f with respect to the surface on which the relay terminal 110 of the electric wiring board 103 is arranged in the second bonding portion 106b is preferably 10 degrees or more and 90 degrees or less. If bonding is performed in the second bonding portion 106b at an angle greater than this, the capillary trajectory when the loop is formed becomes complicated, so that the shape becomes unstable and the bondability of the second bonding portion 106b also becomes unstable. Note that the vertical portion of the electrical connection member 106 does not necessarily need to be perpendicular to the open portion surface 125, and for example, a trapezoid may be formed by the first bonding portion 106a, the first bent portion 106c, the second bent portion 106d, and the second bonding portion 106b. However, it is preferable that the distance between the first bent portion 106c and the first bonding portion 106a of the electrical connection member 106 be shorter than the distance between the second bent portion 106d and the second bonding portion 106b when projected onto a plane perpendicular to the liquid ejection direction.

[0025] Next, a procedure for connecting the electric wiring board 103 to the recording element board 102 will be described with reference to FIG.

[0026] In step S1201, the recording element substrate 102 is placed on a flat surface such as a jig (not shown), for example. Note that hereinafter, "step S~" will be abbreviated to "S~".

[0027] Next, in S1202, the end of the electric wiring board 103 that is closer to the relay terminal 110 in the longitudinal direction is placed on the open surface 125 of the recording element board 102. At this time, the electrode terminals 107 on the open surface 125 are not covered by the electric wiring board 103. Also, the relay terminals 110 are spaced a predetermined distance from the electrode terminals 107.

[0028] Here, as described above, the electric wiring board 103 is avoided from being adhesively fixed to the recording element substrate 102. Instead, the electric wiring board 103 is positioned using a jig (not shown) so that the same positional relationship as when the electric wiring board 103 is adhesively fixed to the recording element substrate 102 is obtained.

[0029] Next, in S1203, the electrode terminals 107 of the recording element substrate 102 and the relay terminals 110 of the electric wiring substrate 103 are electrically connected by the electric connection member 106. At this time, as described above, the electric connection member 106 is formed into the shape shown in FIG. molding do.

[0030] Next, in S1204, the sealant 104 is applied to the electrical connection portion including the electrode terminals 107, the electrical connection members 106, and the relay terminals 110, thereby covering the electrical connection portion with the sealant 104.

[0031] Next, in S1205, the sealant 104 is cured. As a result, the electric wiring board 103 is fixed to the recording element board 102, and the electric connection portion is sealed with the sealant 104.

[0032] Finally, in S1206, the completed liquid ejection unit 101 is removed from the jig.

[0033] Second embodiment Figures 13 and 14 show a liquid ejection unit 101 of the second embodiment in a state in which the sealant 104 has been omitted. In particular, Figure 13 is a schematic perspective view of the liquid ejection unit 101 in a state in which an electric wiring board 103 is connected to a recording element board 102, and Figure 14 is an enlarged perspective view of the electrical connection portion. In these figures, the same components as those in the first embodiment are given the same reference symbols, and below, overlapping descriptions of those components will not be repeated.

[0034] As in the first embodiment, in this embodiment, the electrical connection is sealed with a sealant 104 to protect the wire-bonded electrical connection from external forces and to prevent the electrical connection from corroding due to the liquid for discharge or moisture in the environment. Generally, materials such as epoxy resin are preferably used as the sealant 104, and for example, spherical fillers are added to the sealant 104 to suppress the linear expansion coefficient of the sealant 104. In this embodiment, a material in which 95% by mass of the filler has an outer diameter of 65 μm or less is used as the filler. When sealing is performed using the sealant 104 when the pitch of the electrode terminals is narrow, the pitch of the electrical connection members 106 is also narrow, so that some of the filler in the sealant 104 may not be able to pass through the gaps between the electrical connection members 106 until it reaches under the electrical connection members 106. For example, when the pitch of the electrode terminals is 70 μm and the wire diameter is 5 μm, about 5% of the filler may not be able to pass through in this way. If the wire diameter is 15 μm, the proportion of fillers that cannot pass between the wires increases further. In that case, the density of the filler under the electrical connection member 106 is insufficient, so that the sealant 104 may not be able to exhibit its inherent performance. In addition, the linear expansion coefficient of the filler may be distributed, so that side effects may occur. Therefore, in this embodiment, as shown in FIG. 14, for example, the electrical connection members 106-2 having a first height and the electrical connection members 106-3 having a second height are arranged alternately. By providing a height difference between the electrical connection members 106-2 and 106-3 adjacent to each other in this way, the width of the gap between the electrical connection members 106-2 and 106-3 can be widened. Therefore, it is possible to increase the amount of filler that reaches under the electrical connection members 106-2 and 106-3. Or, it is possible to increase the density of the filler under the electrical connection members 106-2 and 106-3 to the density of the filler over them. Therefore, it is possible to exhibit the inherent performance of the sealant 104, and to stably protect the electrical connection portion.

[0035] In this embodiment as well, the electrical connection members 106-2 and 106-3 are provided with a first bent portion 106c and a second bent portion 106d as shown in FIG.

[0036] Furthermore, the height of each loop formed by the electrical connection members 106-2 and 106-3 can be set arbitrarily in relation to the sealant 104 and other components used.

[0037] Third embodiment This embodiment is basically the same as the second embodiment.

[0038] As shown in Fig. 15, in this embodiment, an electrical connection member 106-4 and an electrical connection member 106-5 are used. The electrical connection members 106-4 and 106-5 are alternately arranged, and a height difference is provided between the electrical connection member 106-4 and the electrical connection member 106-5 so that the electrical connection member 106-4 is higher than the electrical connection member 106-5. The electrical connection member 106-4 is provided with a first bent portion 106c and a second bent portion 106d as shown in Fig. 10, but the electrical connection member 106-5 is not provided with any bent portions.

[0039] According to this embodiment, since the first bent portion 106c and the second bent portion 106d are provided in the electrical connection member 106-4, the force of lifting the electrical wiring board 103 by all the electrical connection members can be halved. Therefore, no gap is generated between the recording element substrate 102 and the electrical wiring board 103, or even if a gap is generated, it is narrow. Therefore, similar to the first embodiment, the electrical wiring board 103 can be fixed to the recording element substrate 102 by the sealant 104, and the electrical connection portion can be protected.

[0040] Furthermore, according to this embodiment, as in the second embodiment, a difference in height is provided between the adjacent electrical connection members 106-4 and 106-5, and therefore the same effects as in the second embodiment can be achieved with respect to the filler.

[0041] (Fourth embodiment) This embodiment is basically the same as the second embodiment.

[0042] As shown in Fig. 16, in this embodiment, an electrical connection member 106-6 and an electrical connection member 106-7 are used. The electrical connection members 106-6 and 106-7 are alternately arranged, and a height difference is provided between the electrical connection member 106-6 and the electrical connection member 106-7 so that the electrical connection member 106-6 is higher than the electrical connection member 106-7. The electrical connection member 106-7 is provided with a first bent portion 106c and a second bent portion 106d as shown in Fig. 10, but the electrical connection member 106-6 is not provided with any bent portions.

[0043] According to this embodiment, since the first bent portion 106c and the second bent portion 106d are provided in the electrical connection member 106-7, the force of lifting the electrical wiring board 103 by all the electrical connection members can be halved. In particular, since the reaction force by the electrical connection member 106-6 of this embodiment is weaker than the reaction force by the electrical connection member 106-5 of the third embodiment, the force of lifting the electrical wiring board 103 by all the electrical connection members can be weakened compared to the third embodiment. Therefore, no gap is generated between the recording element substrate 102 and the electrical wiring substrate 103, or even if a gap is generated, it is narrow. Therefore, similar to the first embodiment, the electrical wiring substrate 103 can be fixed to the recording element substrate 102 by the sealant 104, and the electrical connection portion can be protected.

[0044] Furthermore, according to this embodiment, as in the second embodiment, a difference in height is provided between the adjacent electrical connection members 106-6 and 106-7, and therefore the same effects as in the second embodiment can be achieved with respect to the filler.

[0045] Fifth embodiment This embodiment is basically the same as the second embodiment.

[0046] 17, in this embodiment, electrical connection members 106-8 and 106-9 are used. The electrical connection members 106-8 and 106-9 are alternately arranged, and a height difference is provided between the electrical connection members 106-8 and 106-9 so that the electrical connection members 106-8 are higher than the electrical connection members 106-9. The electrical connection members 106-8 and 106-9 do not have bent portions.

[0047] According to this embodiment, the electric connection member 106-8 and the electric connection member 106-9 are not provided with a bent portion, but the reaction force by the electric connection member 106-8 is weaker than the reaction force by the electric connection member 106-9. Therefore, compared with the case where the height of the electric connection member 106-8 is matched to the height of the electric connection member 106-9, the force of lifting the electric wiring board 103 by all the electric connection members can be reduced. Therefore, no gap is generated between the recording element board 102 and the electric wiring board 103, or even if a gap is generated, it is narrow. Therefore, as in the first embodiment, the electric wiring board 103 can be fixed to the recording element board 102 by the sealant 104, and the electrical connection portion can be protected.

[0048] Furthermore, according to this embodiment, as in the second embodiment, a difference in height is provided between the adjacent electrical connection members 106-8 and 106-9, and therefore the same effects as in the second embodiment can be achieved with respect to the filler.

[0049] Sixth embodiment 18 and 19 show a liquid ejection unit of the sixth embodiment. FIG. 18 is a schematic plan view of the state in which the electric wiring board 103 is connected to the recording element board 102, and FIG. 19 is an enlarged perspective view of the electrical connection portion. As the density of the ejection ports increases, the pitch of each portion, such as the electrode terminals 107 and the relay terminals 110, becomes narrower and narrower. In particular, the electric wiring board 103 has technical restrictions in terms of manufacturing and function compared to the electrode terminals 107 with the current technology. In addition, the relay terminals 110 are disposed at the position where the second bonding is performed, and as the area where the bonding is performed becomes narrower, concerns about the bonding connection arise. Therefore, in this embodiment, in order to avoid the manufacturing and functional restrictions of the electric wiring board 103 as much as possible and to realize a narrow pitch without reducing the connection of the bonding portion, the following is performed. That is, as shown in FIG. 18, the relay terminals 110 at the position where the second bonding is performed on the electric wiring board 103 are disposed alternately shifted in the longitudinal direction of the lead portion 136. 18, the width of the relay terminal 110 can be increased, and the space around the relay terminal 110 can be expanded. Therefore, the pitch of the electric wiring board 103 can be narrowed without deteriorating the bondability of the second bonding portion.

[0050] 19, in this embodiment, the electrical connection member 106-10 corresponding to the relay terminal 110 closer to the electrode terminal 107 has two bent portions, a horizontal portion, and an oblique portion. Also, the electrical connection member 106-11 corresponding to the relay terminal 110 farther from the electrode terminal 107 also has two bent portions, a horizontal portion, and an oblique portion. This is similar to the first embodiment. Also, a height difference is provided between the electrical connection member 106-10 and the electrical connection member 106-11 so that the electrical connection member 106-10 is lower than the electrical connection member 106-11.

[0051] Seventh embodiment Figures 18 and 20 show a liquid ejection unit of the seventh embodiment. Figure 18 is a schematic plan view of a state in which an electric wiring board 103 is connected to a recording element board 102, and Figure 20 is an enlarged perspective view of the electrical connection portion. This embodiment is configured to use two types of electrical connection members: an electrical connection member 106-12 having a loop shape with a bent portion, and an electrical connection member 106-13 having a loop shape without a bent portion.

[0052] 20, in this embodiment, the electrical connection member 106-12 corresponding to the relay terminal 110 closer to the electrode terminal 107 has two bent portions, a horizontal portion, and an oblique portion, similar to the first embodiment. On the other hand, the electrical connection member 106-13 corresponding to the relay terminal 110 farther from the electrode terminal 107 does not have a bent portion. Also, a height difference is provided between the electrical connection member 106-12 and the electrical connection member 106-13 so that the electrical connection member 106-12 is higher than the electrical connection member 106-13. Also, in this embodiment, the width of the lead portion is increased, similar to the third embodiment.

[0053] So far, the importance of providing a bent portion has been explained and applied to the above embodiment. Generally, in order to form a bent portion in the electrical connection member 106, it is necessary to additionally include a so-called forming operation in the trajectory operation of the capillary. Therefore, when a bent portion is formed in the electrical connection member 106, the productivity decreases, although slightly. The configuration for minimizing the decrease in productivity is the present embodiment shown in Figures 18 and 20.

[0054] The shorter the distance from the electrode terminal 107 to the relay terminal 110, the shorter the distance from the first bonding point to the second bonding point. The electrical connection member 106 becomes shorter, and the curvature of the loop shape of the electrical connection member 106 becomes larger. This increases the elastic deformation force of the electrical connection member 106. When the elastic deformation force increases, the reaction force of the electrical connection member 106 that tries to lift the electrical wiring board 103 increases. Therefore, even if only the electrical connection member 106-12 is provided with a bent portion, it is possible to achieve an effect of reducing the reaction force almost equal to the effect of reducing the reaction force, compared to the case where both the electrical connection member 106-12 and the electrical connection member 106-13 are provided with bent portions. Furthermore, if only the electrical connection member 106-12 is provided with a bent portion, it is possible to reduce manufacturing costs, compared to the case where both the electrical connection member 106-12 and the electrical connection member 106-13 are provided with bent portions.

[0055] Eighth embodiment In this embodiment, similarly to the sixth and fifth embodiments, adjacent electrical connection members 106 have different distances from the electrode terminal 107 to the relay terminal 110. If the electrical connection member with the shorter distance is designated as the first electrical connection member and the electrical connection member with the longer distance is designated as the second electrical connection member, the shapes can be classified according to the heights of the first and second electrical connection members and the presence or absence of a bent portion, as shown in the table of FIG.

[0056] Regarding the height, there are three cases: the first electrical connection member and the second electrical connection member have the same height, the first electrical connection member is higher than the second electrical connection member, and the first electrical connection member is lower than the second electrical connection member. Regarding the presence or absence of a bent portion of the first electrical connection member, there are two cases: the first electrical connection member has a bent portion and the first electrical connection member does not have a bent portion. Regarding the presence or absence of a bent portion of the second electrical connection member, there are two cases: the second electrical connection member has a bent portion and the second electrical connection member does not have a bent portion. Therefore, there are a total of 12 shapes 2101 to 2112. The sixth embodiment corresponds to the shape 2112. The seventh embodiment corresponds to the shape 2107.

[0057] The curvature of the second electrical connection member can be made smaller than when the distance from the electrode terminal 107 of the second electrical connection member to the relay terminal 110 is set to the same as the distance from the electrode terminal 107 of the first electrical connection member to the relay terminal 110. Therefore, regardless of the shape, the total value of the reaction forces due to all the electrical connection members can be made smaller than in such a case.

[0058] Furthermore, by simply providing a bent portion only on the first electrical connection member, the total reaction force of all electrical connection members can be further reduced.Similarly, by simply providing a bent portion only on the second electrical connection member, the total reaction force of all electrical connection members can be further reduced.

[0059] Furthermore, simply increasing the height of the first electrical connection member can reduce its curvature, which in turn can further reduce the total reaction force of all electrical connection members. Simply increasing the height of the second electrical connection member can also reduce its curvature, which in turn can further reduce the total reaction force of all electrical connection members.

[0060] (Other embodiments) In the above embodiment, the electrical connection member 106 has a first bent portion 106c and a second bent portion 106d. In contrast, in the present embodiment, the electrical connection member 106 has one bent portion or three or more bent portions. When the electrical connection member 106 has one bent portion, the interior angle at the bent portion of the electrical connection member 106 is an acute angle, and the first bonding portion, the second bonding portion, and the bent portion form a triangle. When the electrical connection member 106 has three bent portions, the first bonding portion, the second bonding portion, and the three bent portions form a pentagon.

[0061] In the sixth to ninth embodiments, there are two different distances from the electrode terminal 107 to the relay terminal 110, but in this embodiment, there are three or more different distances. For example, when there are three different distances, the electrical connection members may be arranged so that a short distance, a medium distance, and a long distance are repeated, or the electrical connection members may be arranged so that a short distance, a medium distance, a long distance, and a medium distance are repeated.

[0062] In the above embodiment, the liquid ejection direction coincides with the normal direction of the surface (open portion surface 125) where the electrode terminals 107 of the recording element substrate 102 are exposed, and with the normal direction of the surface where the relay terminals 110 of the electric wiring substrate 103 are exposed. However, for example, if the electric wiring substrate 103 is an FPC, the normal direction of the surface where the relay terminals 110 of the electric wiring substrate 103 are exposed may not coincide with the other two. Also, if the open portion surface 125 is formed at an angle, the normal direction of the open portion surface does not coincide with the other two. If the two are combined, the above three are mutually different.

[0063] In these cases, the direction of the portion of the electrical connection member 106 from the first bonding portion 106a to the first bent portion 106c may be aligned with the liquid ejection direction. Also, the direction of the portion of the electrical connection member 106 from the first bonding portion 106a to the first bent portion 106c may be aligned with the normal direction to the open portion surface 125. Furthermore, the direction of the portion of the electrical connection member 106 from the first bonding portion 106a to the first bent portion 106c may be aligned with the normal direction to the surface of the electrical wiring board 103 on which the relay terminal 110 is exposed. Furthermore, the direction of the portion of the electrical connection member 106 from the first bonding portion 106a to the first bent portion 106c may be aligned with any of these three directions.

[0064] The direction of the portion of the electrical connection member 106 from the first bent portion 106c to the second bent portion 106d may be perpendicular to the liquid ejection direction. Also, the direction of the portion of the electrical connection member 106 from the first bent portion 106c to the second bent portion 106d may be parallel to the open portion surface 125. Furthermore, the direction of the portion of the electrical connection member 106 from the first bent portion 106c to the second bent portion 106d may be parallel to the surface on which the relay terminal 110 of the electrical wiring board 103 is exposed. Furthermore, the direction of the portion of the electrical connection member 106 from the first bent portion 106c to the second bent portion 106d may be similar to any of these three directions.

[0065] The direction of the portion of the electrical connection member 106 from the second bonding portion 106b to the second bent portion 106d may be set to have an angle of 10 degrees or more and 90 degrees or less with respect to a plane perpendicular to the liquid ejection direction. Also, the direction of the portion of the electrical connection member 106 from the second bonding portion 106b to the second bent portion 106d may be set to have an angle of 10 degrees or more and 90 degrees or less with respect to the open portion surface 125. Furthermore, the direction of the portion of the electrical connection member 106 from the second bonding portion 106b to the second bent portion 106d may be set to have an angle of 10 degrees or more and 90 degrees or less with respect to the surface on which the relay terminal 110 of the electrical wiring board 103 is exposed. Furthermore, the direction of the portion of the electrical connection member 106 from the second bonding portion 106b to the second bent portion 106d may be set to a direction that is close to any of these three directions.

[0066] In any of the above embodiments, the reaction force of the wire can be reduced and the effect of preventing the electric wiring board from being lifted can be improved by thinning the diameter of the wire used as the electrical connection member 106. The specific wire diameter may be selected according to the performance required for the liquid ejection unit 101, the electrode size, the inter-electrode pitch, and the like.

[0067] The above describes the embodiments of the present disclosure. In recent years, liquid ejection technology or inkjet recording technology has come to be applied to media other than paper media, such as printed wiring boards. Liquid ejection units used for such purposes and liquid ejection devices equipped with liquid ejection units are required to have high reliability as industrial equipment, and the liquid ejection unit based on the present disclosure is capable of satisfying this reliability requirement. Furthermore, the liquid ejection unit of the present disclosure can be used to configure a liquid ejection recording device that can maintain high recording quality even during high-speed recording.

[0068] The liquid ejection unit according to the present disclosure is capable of ejecting various liquids in addition to ink used in inkjet recording to perform recording. Furthermore, the liquid ejection unit according to the present disclosure can be used to perform various processes (recording, processing, coating, irradiation) on various media. The media covered here include so-called recording media, as well as various media to which liquid can be applied, whether in sheet form or not, such as paper, plastic, film, textile, metal, flexible substrate, etc.

[0069] <Technical Features of the Present Disclosure> The present disclosure includes the following configurations and methods.

[0070] (Configuration 1) a recording element substrate having ejection ports for ejecting liquid, energy generating elements for generating energy for ejecting liquid from the ejection ports, and electrode terminals electrically connected to the energy generating elements; an electric wiring board having relay terminals for electrically connecting to the electrode terminals; an electrical connection member having a first connection end connected to the electrode terminal of the recording element substrate, a second connection end connected to the relay terminal of the electrical wiring substrate, and a connecting portion configured to connect between the first connection end and the second connection end; a sealant configured to cover an electrical connection portion including at least the electrical connection member, the electrode terminal, and the relay terminal; Equipped with The liquid ejection unit, wherein the electrical connection member has at least one bending point at the joint.

[0071] (Configuration 2) A liquid ejection unit as described in configuration 1, wherein the at least one bending point of the connecting portion of the electrical connection member includes a first bending point and a second bending point, and of the at least one bending point, the first bending point is closest to the first connection end and the second bending point is closest to the second connection end.

[0072] (Configuration 3) A liquid ejection unit as described in configuration 2, wherein the distance between the first bending point and the first connection end of the electrical connection member when projected onto a plane perpendicular to the ejection direction of the liquid is shorter than the distance between the second bending point and the second connection end.

[0073] (Configuration 4) A liquid ejection unit according to configuration 3, wherein the liquid ejection direction is changed to a normal direction of a surface on which the electrode terminals of the recording element substrate are exposed, a normal direction of a surface on which the relay terminals of the electrical wiring substrate are exposed, or a direction approximating any of these three directions.

[0074] (Configuration 5) A liquid ejection unit described in any one of configurations 2 to 4, having a horizontal portion between the first bending point and the second bending point of the electrical connection member that is approximately parallel to the open portion surface on which the electrode terminals of the recording element substrate are arranged.

[0075] (Configuration 6) The liquid ejection unit according to configuration 5, wherein the horizontal portion of the electrical connection member is also approximately parallel to a surface of the electrical wiring board on which the relay terminals are disposed.

[0076] (Configuration 7) 7. The liquid ejection unit according to configuration 5 or 6, wherein the horizontal portion of the electrical connection member has a length of 50 μm or more and 500 μm or less.

[0077] (Configuration 8) A liquid ejection unit described in any one of configurations 2 to 7, wherein the angle of a line segment connecting the second bending point and the second connection end of the electrical connection member with respect to the surface on which the relay terminal of the electrical wiring board is arranged is greater than or equal to 10 degrees and less than or equal to 90 degrees.

[0078] (Configuration 9) the recording element substrate has a plurality of the energy generating elements and a plurality of the electrode terminals, the energy generating elements and the electrode terminals being electrically connected to each other; the electric wiring board has a plurality of the relay terminals corresponding to the plurality of electrode terminals, a plurality of the electrical connection members are provided to electrically connect the electrode terminals and the relay terminals to each other, A liquid ejection unit described in any one of configurations 1 to 8, wherein each of the multiple electrical connection members has a different maximum height from the open surface on which the electrode terminals of the recording element substrate are arranged, compared to adjacent electrical connection members.

[0079] (Configuration 10) the recording element substrate has a plurality of the energy generating elements and a plurality of the electrode terminals, the energy generating elements and the electrode terminals being electrically connected to each other; the electric wiring board has a plurality of the relay terminals corresponding to the plurality of electrode terminals, a plurality of the electrical connection members are provided to electrically connect the electrode terminals and the relay terminals to each other, The liquid ejection unit according to any one of configurations 1 to 8, wherein the position of the second connection end of each of the plurality of electrical connection members is shifted in the extension direction of the electrical wiring board with respect to an adjacent electrical connection member.

[0080] (Configuration 11) The electrical connection member, in which the second connection end is spaced apart from the first connection end by a distance shorter than a predetermined distance, has at least one of the bending points in the joint portion, The electrical connection member in which the second connection end is spaced from the first connection end by a distance longer than the predetermined distance does not have the bending point in the joint portion. 11. A liquid ejection unit according to configuration 10.

[0081] (Configuration 12) At least a portion of the plurality of electrical connection members does not have the bending point at the joint portion. 11. A liquid ejection unit according to configuration 10.

[0082] (Configuration 13) 13. The liquid ejection unit according to any one of configurations 1 to 12, wherein the electrical connection member is plastically deformed at at least one bending point included in the at least one bending point.

[0083] (Configuration 14) a recording element substrate having ejection ports for ejecting liquid, energy generating elements for generating energy for ejecting liquid from the ejection ports, and electrode terminals electrically connected to the energy generating elements; an electric wiring board having relay terminals for electrically connecting to the electrode terminals; an electrical connection member having a first connection end connected to the electrode terminal of the recording element substrate, a second connection end connected to the relay terminal of the electrical wiring substrate, and a connecting portion configured to connect between the first connection end and the second connection end; a sealant configured to cover an electrical connection portion including at least the electrical connection member, the electrode terminal, and the relay terminal; Equipped with the recording element substrate has a plurality of the energy generating elements and a plurality of the electrode terminals, the energy generating elements and the electrode terminals being electrically connected to each other; the electric wiring board has a plurality of the relay terminals corresponding to the plurality of electrode terminals, a plurality of the electrical connection members are provided to electrically connect the electrode terminals and the relay terminals to each other, A liquid ejection unit in which each of the plurality of electrical connection members has a different maximum height from a surface of an open portion on which the electrode terminals of the recording element substrate are disposed, relative to adjacent electrical connection members.

[0084] (Configuration 15) a recording element substrate having ejection ports for ejecting liquid, energy generating elements for generating energy for ejecting liquid from the ejection ports, and electrode terminals electrically connected to the energy generating elements; an electric wiring board having relay terminals for electrically connecting to the electrode terminals; an electrical connection member having a first connection end connected to the electrode terminal of the recording element substrate, a second connection end connected to the relay terminal of the electrical wiring substrate, and a connecting portion configured to connect between the first connection end and the second connection end; a sealant configured to cover an electrical connection portion including at least the electrical connection member, the electrode terminal, and the relay terminal; Equipped with the recording element substrate has a plurality of the energy generating elements and a plurality of the electrode terminals, the energy generating elements and the electrode terminals being electrically connected to each other; the electric wiring board has a plurality of the relay terminals corresponding to the plurality of electrode terminals, a plurality of the electrical connection members are provided to electrically connect the electrode terminals and the relay terminals to each other, The liquid ejection unit has a second connection end portion of each of the plurality of electrical connection members that is shifted from an adjacent electrical connection member in an extending direction of the electrical wiring board.

[0085] (Configuration 16) At least some of the electrical connection members have at least one bending point at the joint. 16. A liquid ejection unit according to configuration 14 or 15.

[0086] (Method 1) a disposing step of disposing a recording element substrate having an ejection port for ejecting liquid, an energy generating element for generating energy for ejecting liquid from the ejection port, and an electrode terminal electrically connected to the energy generating element, and an electric wiring substrate having a relay terminal for electrically connecting to the electrode terminal, so that the electrode terminal and the relay terminal are adjacent to each other; a connecting step of connecting a first connection end of an electrical connection member having a first connection end, a second connection end, and a connecting portion configured to connect between the first connection end and the second connection end to the electrode terminal of the recording element substrate, and connecting the second connection end of the electrical connection member to the relay terminal of the electrical wiring board; a covering step of covering at least the electrical connection portion including the electrical connection member, the electrode terminal, and the relay terminal with a sealant; having In the connecting step, the electrical connection member is molded so that the electrical connection member has at least one bending point at the joint portion. A method for manufacturing a liquid ejection unit. [Explanation of symbols]

[0087] 101 Liquid discharge unit 102 Recording element substrate 103 Electrical wiring board 104 Sealant 106 Electrical connection parts 107 Electrode terminal 108 Energy generating element 109 Discharge port 110 Relay terminal

Claims

1. a recording element substrate having an ejection port for ejecting a liquid, an energy generating element for generating energy for ejecting the liquid from the ejection port, and an electrode terminal electrically connected to the energy generating element; an electric wiring substrate having a relay terminal for electrically connecting to the electrode terminal and joined to the recording element substrate; and a wire for connecting the electrode terminal of the recording element substrate and the relay terminal of the electric wiring substrate; the recording element substrate has a plurality of the energy generating elements and a plurality of the electrode terminals, the energy generating elements and the electrode terminals being electrically connected to each other; the electric wiring board has a plurality of the relay terminals corresponding to the plurality of the electrode terminals, a plurality of wires are provided to electrically connect the electrode terminals and the relay terminals to each other; The relay terminals are arranged so as to be shifted alternately with respect to adjacent relay terminals in an extending direction of the wire, The plurality of wires include first wires and second wires that are adjacent to each other and alternate in an arrangement direction of the plurality of wires, the second wires having a length in the extension direction greater than that of the first wires, a disposing step of disposing an electric wiring board so as to be in contact with the recording element board; a connecting step of connecting the electrode terminals of the recording element substrate and the relay terminals of the electric wiring substrate with the wires by wire bonding; a covering step of covering at least the electrical connection portion including the wire, the electrode terminal, and the relay terminal with a sealant; having In the connecting step, the first wire is shaped so as to have at least one plastically deformed bending point and so as to have a greater maximum height from a surface of an opening portion of the recording element substrate on which the electrode terminals are disposed, than the adjacent second wire. A method for manufacturing a liquid ejection unit.

2. In the connecting step, the first connection end of the wire has a first connection end, a second connection end, and a connecting portion configured to connect between the first connection end and the second connection end, the first connection end of the wire is connected to the electrode terminal of the recording element substrate, and the second connection end of the wire is connected to the relay terminal of the electrical wiring board, The method for manufacturing a liquid discharge unit according to claim 1 , wherein at least one of the bending points is provided in the connecting portion of the first wire.

3. The method for manufacturing a liquid discharge unit according to claim 2 , wherein in the connecting step, the second wire is formed so as not to have a bending point at the connecting portion.

4. a recording element substrate having an ejection port for ejecting a liquid, an energy generating element for generating energy for ejecting the liquid from the ejection port, and an electrode terminal electrically connected to the energy generating element; an electric wiring board having relay terminals for electrically connecting to the electrode terminals and joined to the recording element board; a wire having a first connection end connected to the electrode terminal of the recording element substrate, a second connection end connected to the relay terminal of the electric wiring substrate, and a connecting portion configured to connect between the first connection end and the second connection end; a sealant configured to cover an electrical connection portion including at least the wire, the electrode terminal, and the relay terminal; A liquid ejection unit comprising: the recording element substrate has a plurality of the energy generating elements and a plurality of the electrode terminals, the energy generating elements and the electrode terminals being electrically connected to each other; the electric wiring board has a plurality of the relay terminals corresponding to the plurality of the electrode terminals, a plurality of wires are provided to electrically connect the electrode terminals and the relay terminals to each other; The relay terminals are arranged so as to be shifted alternately with respect to adjacent relay terminals in an extending direction of the wire, The plurality of wires include a first wire and a second wire that is longer than the first wire in the extending direction and that is alternately arranged adjacent to each other in an arrangement direction of the plurality of wires, the first wire has at least one plastically deformed bending point at the connecting portion; The liquid ejection unit according to claim 1, wherein the first wire has a greater maximum height from a surface of an open portion of the recording element substrate, the surface being provided with the electrode terminals, than the adjacent second wire.

5. The liquid ejection unit according to claim 4 , wherein the electric wiring board is fixed to the recording element board by the sealant.

6. The liquid ejection unit of claim 4, wherein the at least one bend point of the connecting portion of the first wire includes a first bend point and a second bend point, and of the at least one bend point, the first bend point is closest to the first connection end and the second bend point is closest to the second connection end.

7. The liquid ejection unit according to claim 6, wherein the distance between the first bend point and the first connection end of the first wire when projected onto a plane perpendicular to the liquid ejection direction is shorter than the distance between the second bend point and the second connection end.

8. The liquid ejection unit according to claim 6 , further comprising a horizontal portion between the first bend point and the second bend point of the first wire, the horizontal portion being approximately parallel to a surface of an open portion on which the electrode terminal of the recording element substrate is disposed.

9. The liquid ejection unit according to claim 8 , wherein the horizontal portion of the first wire is also approximately parallel to a surface of the electric wiring board on which the relay terminal is disposed.

10. The liquid ejection unit according to claim 8 , wherein the horizontal portion of the first wire has a length of 50 μm or more and 500 μm or less.

11. A liquid ejection unit as described in claim 6, wherein an angle of a line segment connecting the second bend point and the second connection end of the first wire with respect to a surface on which the relay terminal of the electrical wiring board is disposed is greater than or equal to 10 degrees and less than or equal to 90 degrees.

12. The liquid ejection unit according to claim 4 , wherein the second wire does not have a bending point at the connecting portion.

13. The liquid ejection unit according to claim 4 , wherein the energy generating element is a piezoelectric element.

14. A liquid ejection unit described in any one of claims 4 to 12, wherein the sealant includes a filler.

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