Liquid ejection head and manufacturing method thereof

Abstract

To provide a liquid ejection head ensuring the reliability of an electric connection portion between a recording element substrate and an electrical wiring substrate.SOLUTION: A liquid ejection head 1 includes: a recording element substrate 2 having an ejection port 9, an energy generating element 8 that generates energy for ejection, and an electrode terminal 7 electrically connected to the energy generating element; and an electrical wiring substrate 3 electrically connected to the electrode terminal 7 by wire bonding or the like. The electrode terminal 7 is disposed on a connection surface 25, which is one surface of the recording element substrate 2, and, at an end of the electrical wiring substrate 3, is provided with a connection region that is electrically connected to the electrode terminal 7. The end of the electrical wiring substrate 3 is disposed apart from the electrode terminal 7 on a surface of the recording element substrate 2 which surface is on a side of the connection surface 25.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] A liquid ejection head, typified by an inkjet recording head, is provided with 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. Electrical wiring boards such as FPCs (flexible printed circuits) and TABs (tape automated bonding) are used to supply power, signals, and the like from the main body of a liquid ejection device equipped with the liquid ejection head to the recording element substrate. Patent Document 1 discloses that, in a liquid ejection head, the electrical wiring board and the electrode terminals of the recording element substrate are electrically connected by wire bonding, and that this electrical connection is further protected by a sealant. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 9,950,511 Summary of the Invention [Problem to be solved by the invention]

[0004] When wire bonding is performed, heat, pressure, ultrasonic waves, etc. are applied at the connection position, so it is necessary to support the components to be connected. The liquid ejection head shown in Patent Document 1 does not have a member to support the electrical wiring board, so it is necessary to support the electrical wiring board with a jig during wire bonding. When using a jig, steps may occur due to thickness tolerances, making stable support impossible, and the reliability of the electrical connection may be compromised.

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid ejection head in which reliability is ensured in the electrical connection between the recording element substrate and the electrical wiring substrate, and a method for manufacturing the same. [Means for solving the problem]

[0006] A liquid ejection head according to the present invention comprises: 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; and an electric wiring substrate electrically connected to the electrode terminals; The ejection ports are arranged on one surface of the recording element substrate, The electrode terminals are The other side is the reverse side of one side. The end of the electrical wiring board is electrically connected to the electrode terminal. Contains conductors A connection area is provided, Connection Area teeth, Affixed to the other surface by adhesive, spaced apart from the electrode terminal. Placed On the other surface of the recording element substrate, a groove is formed between the connection area and the electrode terminal. It is characterized by the presence of [Effects of the Invention]

[0007] According to the present invention, it is possible to obtain a liquid ejection head in which reliability is ensured in the electrical connection between the recording element substrate and the electrical wiring substrate. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing a liquid ejection head according to a first embodiment to which the present invention can be applied; [Figure 2] 3A and 3B are diagrams illustrating electrical connection portions in the first embodiment. [Figure 3] 10A and 10B are diagrams illustrating electrical connection portions in the second embodiment. [Figure 4] 10A and 10B are diagrams illustrating electrical connection portions in the third embodiment. [Figure 5] 10A and 10B are diagrams illustrating electrical connection portions in a fourth embodiment. [Figure 6] 10A and 10B are diagrams illustrating electrical connection portions in the fifth embodiment. [Figure 7] 13A and 13B are diagrams illustrating an electrical connection portion in the sixth embodiment. [Figure 8] 10A and 10B are diagrams illustrating a liquid ejection head according to a seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Next, embodiments to which the present invention can be applied will be described with reference to the drawings. A liquid ejection head based on the present invention has at least a recording element substrate and an electrical wiring substrate. The recording element substrate has 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. The electrical wiring substrate is electrically connected to the electrode terminals of the recording element substrate. Several embodiments of such a liquid ejection head based on the present invention will be described below, but these embodiments do not limit the scope of the present invention.

[0010] As an example, the following embodiments describe a thermal liquid ejection head that uses electrothermal transducers as energy generating elements to apply heat to the liquid, generating bubbles and ejecting the liquid from the ejection ports. However, the present invention can also be applied to liquid ejection heads other than thermal liquid ejection heads. In particular, the present invention is suitable for piezoelectric liquid ejection heads that use piezoelectric elements as energy generating elements. In a piezoelectric liquid ejection head, the number of individual flow paths is equal to the number of ejection ports that eject droplets, and each individual flow path is equipped with a piezoelectric element that generates pressure for ejection. To achieve high-density ejection port arrangement without changing the dimensions of the recording element substrate, the number of piezoelectric elements must be increased, which in turn increases the number of electrode terminals. To accommodate the electrode terminals within a limited area, the pitch between the electrode terminals must be narrowed. According to the present invention, high reliability can be achieved in the electrical connection between the recording element substrate and the electrical wiring board, even when the pitch between the electrode terminals is narrow.

[0011] [First embodiment] 1 and 2 are diagrams showing a liquid ejection head according to a first embodiment to which the present invention can be applied. FIG. 1(a) is a perspective view of the liquid ejection head 1, FIG. 1(b) is an exploded perspective view showing the liquid ejection head 1 in a state in which the recording element substrate 2 and the electrical wiring substrate 3 are separated, and FIG. 1(c) is a cross-sectional view taken along line CC in FIG. 1(b) showing a main portion of the recording element substrate 2. FIG. 2(a) is a cross-sectional view taken along line AA in FIG. 1(a) showing a main portion of the liquid ejection head 1 in a state in which the electrical wiring substrate 3 is connected to the recording element substrate 2, and FIG. 2(b) is a plan view showing the electrical connection portion between the recording element substrate 2 and the electrical wiring substrate 3. For ease of understanding, the sealant 4 and adhesive 5 are not depicted in FIG. 2(b).

[0012] As shown in FIG. 1(a), the liquid ejection head 1 includes a recording element substrate 2 and an electric wiring board 3 connected to the recording element substrate 2. A plurality of ejection ports 9 for ejecting liquid are arranged on one surface (the upper surface in the figure) of the recording element substrate 2. As shown in FIG. 1(b), the electric wiring board 3 is a thin, flexible, elongated member made of, for example, an FPC or a TAB, and is used to supply power and signals from the main body of a liquid ejection device incorporating the liquid ejection head to the recording element substrate. At one end of the electric wiring board 3 in the longitudinal direction (the direction in which the wiring inside the electric wiring board 3 extends), a plurality of connection areas 10 are formed, where the conductors are exposed in the form of pads and are used for connection with the electrode terminals 7 of the recording element substrate 2. At the other end of the electric wiring board 3 in the longitudinal direction, a plurality of connection terminals 31 are formed, where the conductors are exposed in the form of pads. The connection areas 10 and the connection terminals 31 are electrically connected one-to-one by a plurality of conductor patterns 32 (see FIG. 2(b)) formed on a conductor layer inside the electric wiring board 3.

[0013] As shown in FIG. 1( c), the recording element substrate 2 is mainly composed of energy generating elements 8, a discharge port forming member 21 in which discharge ports 9 are formed, a wiring layer 22, and a base portion 23 made of a silicon substrate. The discharge port forming member 21 is disposed on one surface of the base portion 23. Electrode terminals 7 are formed on the other surface of the base portion 23, resulting in a plurality of electrode terminals 7 being disposed on the other surface of the recording element substrate 2. In the following description, of the pair of surfaces of the recording element substrate 2, the surface on which the electrode terminals 7 are formed is also referred to as a connection surface 25. In this embodiment, the surface of the base portion 23 made of a silicon substrate opposite to the surface on which the discharge port forming member 21 is provided constitutes the connection surface 25. Recesses are formed on the surface of the discharge port forming member 21 facing the base portion 23 at and near the positions where the discharge ports 9 are formed, and these recesses constitute pressure chambers 24 that communicate with the discharge ports 9. The energy generating elements 8 are arranged so as to impart energy to the liquid in the pressure chambers 24, and the wiring layer 22 is configured to electrically connect the energy generating elements 8 to the electrode terminals 7. When the energy generating elements 8 are electrothermal converters, the energy generating elements 8 are arranged on one surface of the base portion 23, and the wiring layer 22 is arranged on the joint surface between the one surface of the base portion 23 and the ejection port forming member 21. In this case, the wiring layer 22 formed on one surface of the base portion 23 and the electrode terminals 7 formed on the other surface are electrically connected by, for example, via holes. On the other hand, when the energy generating elements 8 are piezoelectric elements, the piezoelectric elements and the wiring layer 2 are formed inside the base portion 23, for example, and a vibration plate is arranged between the piezoelectric elements and the pressure chambers. Note that a circuit (not shown) including a transistor, an integrated circuit, etc. may be provided between the energy generating elements 8 and the electrode terminals 7, and the energy generating elements 8 may be electrically connected to the electrode terminals 7 via this circuit.

[0014] Next, the connection between the recording element substrate 2 and the electrical wiring substrate 3 will be described. The recording element substrate 2 and the electrical wiring substrate 3 are electrically connected by connecting the electrode terminals 7 of the recording element substrate 2 to the connection areas 10 of the electrical wiring substrate 3 using an electrical connection member 6. The electrical connection member 6 is typically a conductor wire (i.e., a bonding wire) for connection, and is bonded to the electrode terminals 7 and the connection areas 10, respectively, using a wire bonding technique. In this embodiment, the electrical connection member 6 is, for example, a gold wire. The electrical connection member 6 is not limited to a gold wire, but may be any material primarily composed of, for example, any one of gold, copper, aluminum, and silver, or an alloy containing two or more of these metals. As is well known, in wire bonding, when a connecting wire is bonded to a connection target, at least one of heat, pressure, and ultrasonic waves must be applied to the interface, i.e., the joint, between the wire and the connection target. Therefore, the connection target must be supported in some form during wire bonding. In this embodiment, the recording element substrate 2 is rigid. Therefore, by placing the recording element substrate 2 on a workbench or the like with the electrode terminals 7 facing upward, the recording element substrate 2 can be stably supported for wire bonding. In contrast, the electrical wiring substrate 3 is thin and flexible, so it must be intentionally supported during wire bonding. If a jig were used to support the electrical wiring substrate 3, differences in the thickness of the jig, recording element substrate 2, and electrical wiring substrate 3 could result in unevenness, making the support of the electrical wiring substrate 3 unstable and preventing the appropriate application of pressure or ultrasonic waves. This could result in a decrease in the reliability of the electrical connection between the recording element substrate 2 and electrical wiring substrate 3. While it is possible to prevent unevenness during wire bonding by attaching a support member to the recording element substrate 2 in advance to support the electrical wiring substrate 3, this would increase component and manufacturing costs.

[0015] Therefore, in the liquid ejection head 1 of this embodiment, the electrical wiring substrate 3 is supported by the recording element substrate 2 itself during wire bonding, thereby avoiding unstable support due to the generation of steps and the need for additional support members. Specifically, as shown in FIG. 2 , in the liquid ejection head 1 of this embodiment, one end of the electrical wiring substrate 3 is located on the other surface of the recording element substrate 2, i.e., the surface on which the electrode terminals 7 are formed, and is spaced apart from the electrode terminals 7. One end of the electrical wiring substrate 3 is provided with a connection area 10 for electrical connection with the electrode terminals 7, and the connection area 10 is located on the other surface of the recording element substrate 2. The entire electrical connection between the recording element substrate 2 and the electrical wiring substrate 3, including the electrode terminals 7 of the recording element substrate 2, the connection area 10 of the electrical wiring substrate 3, and the electrical connection member 6, is sealed and protected by a sealant 4. It is preferable that the sealant 4 have rigidity to protect the electrical connection from external forces and also have the function of suppressing corrosion from the ejection liquid, humidity in the environment, and the like. For this reason, a material such as epoxy resin is preferably used for the sealant 4, but any appropriate material can be used for the sealant 4 depending on the performance required of the sealant 4. In the illustrated example, one end of the electrical wiring board 3 is fixed to the other surface of the recording element board 2, i.e., the connection surface 25, with an adhesive 5.

[0016] Next, the procedure for connecting the electrical wiring board 3 to the recording element substrate 2 will be described. Once the recording element substrate 2 is completed during the manufacturing process of the liquid ejection head 1, the recording element substrate 2 is supported so that the connection surface 25, i.e., the surface on which the electrode terminals 7 are provided, faces upward. For example, the recording element substrate 2 is placed on a fixed flat surface such as a workbench. Next, one end of the electrical wiring board 3 is placed on the connection surface 25 of the recording element substrate 2, spaced apart from the electrode terminals 7, so that the connection area 10 is located above the connection surface 25. While it is possible to leave the electrical wiring board 3 unattached to the recording element substrate 2, it is preferable to use a material such as an adhesive 5 or adhesive sheet to secure the electrical wiring board 3 to the recording element substrate 2, which stabilizes the position between the two and enables a more reliable electrical connection. Instead of using the adhesive 5 or adhesive sheet, any method that can fix the position of one end of the electrical wiring board 3 can be used. Next, the electrode terminals 7 and the connection area 10 of the electrical wiring board 3 are electrically connected using an electrical connection member 6. The electrical connection portion, including the electrode terminals 7, the electrical connection member 6, and the connection area 10, is then covered and protected with a sealant 4. As a result, the liquid ejection head 1 shown in FIG. 1(a) is completed.

[0017] In this embodiment, the electrode terminals 7 and the electrical wiring board 3 are connected by wire bonding using the electrical connection member 6. When performing wire bonding, a bonding tool is used to apply heat, pressure, ultrasonic waves, and the like while the electrical connection member 6 is brought into contact with the electrode terminals 7 and the connection region 10. As a result, one end of the electrical connection member 6 is bonded to the electrode terminals 7 and the other end is bonded to the connection region 10, completing the electrical connection between the electrode terminals 7 and the connection region 10. The bonding region of the electrode terminals 7 is located on the connection surface 25, i.e., the flat upper surface, of the recording element substrate 2 placed on the work table. Because the recording element substrate 2 is a highly rigid member, heat, pressure, ultrasonic waves, and the like can be efficiently transmitted to the interface between the electrical connection member 6 and the electrode terminals 7. This enables stable bonding between the electrode terminals 7 and the electrical connection member 6. Furthermore, because the connection region 10 of the electrical wiring board 3 is also located above the connection surface 25 of the recording element substrate 2, heat, pressure, ultrasonic waves, and the like, which are necessary conditions for stable wire bonding, can be efficiently transmitted to the interface between the electrical connection member 6 and the connection region 10. This enables stable bonding between the connection region 10 and the electrical connection member 6. Ultimately, according to this embodiment, a highly reliable electrical connection can be established between the recording element substrate 2 and the electrical wiring board 3 without using a jig or providing an additional support member, thereby obtaining a liquid ejection head with a highly reliable electrical connection. Furthermore, compared to the one disclosed in Patent Document 1, the length of the electrical connection member 6 itself, which is a bonding wire, can be shortened. This reduces power loss and makes it less susceptible to noise, thereby preventing problems in signal transmission. Furthermore, shortening the length of the electrical wiring member 6, which is, for example, a gold wire, also reduces the amount of wire used, thereby enabling a reduction in component costs.

[0018] [Second embodiment] FIG. 3 shows a liquid ejection head 1 according to a second embodiment. FIG. 3(a) is a cross-sectional view similar to FIG. 2(a) showing a main portion of the liquid ejection head 1 with the recording element substrate 2 and the electrical wiring substrate 3 connected thereto. FIG. 3(b) is a plan view similar to FIG. 2(b) showing the electrical connection between the recording element substrate 2 and the electrical wiring substrate 3. In these figures, the same components as those in the first embodiment are designated by the same reference numerals, and redundant description of these components will not be repeated below. As described in the first embodiment, when one end of the electrical wiring substrate 3 is fixed to the connection surface 25 of the recording element substrate 2 with adhesive 5 or the like, the position of the electrical wiring substrate 3 is stabilized, enabling stable wire bonding. However, if the distance between the tip of one end of the electrical wiring substrate 3 and the electrode terminal 7 is small or if the amount of adhesive 5 applied is too large, the adhesive 5 may overflow onto the electrode terminal 7 and adhere to the electrode terminal 7 when the electrical wiring substrate 3 is fixed with the adhesive 5. If the adhesive 5 adheres to the electrode terminals 7, it may adversely affect wire bonding and reduce the reliability of the electrical connection. Therefore, in the liquid ejection head of the second embodiment, grooves 15 are formed in advance on the connection surface 25 of the recording element substrate 2 between the electrode terminals 7 and a position where the tip of one end of the electrical wiring board 3 will be located. By forming the grooves 15 on the connection surface 25, excess adhesive that spills out when the electrical wiring board 3 is adhesively fixed to the recording element substrate 2 is captured in the grooves 15, thereby preventing the adhesive 5 from spilling out onto the electrode terminals 7. In the illustrated example, the grooves 15 are formed as a single linear groove, but the shape and number of the grooves 15 can be changed as appropriate depending on the state of the spilled adhesive 5. For example, the grooves 15 can be formed in a U-shape on the connection surface 25 of the recording element substrate 2, or the grooves 15 may be formed by multiple divided grooves.

[0019] [Third embodiment] FIG. 4 shows a liquid ejection head 1 according to a third embodiment. FIG. 4(a) is a cross-sectional view similar to FIG. 2(a) showing a main portion of the liquid ejection head 1 with the recording element substrate 2 and the electrical wiring substrate 3 connected thereto. FIG. 4(b) is a plan view similar to FIG. 2(b) showing the electrical connection between the recording element substrate 2 and the electrical wiring substrate 3. In the second embodiment, grooves 15 are formed on the connection surface 25 of the recording element substrate 2 to prevent the adhesive 5 from spilling out toward the electrode terminals 7. In the third embodiment, grooves 16 are formed on the surface of the electrical wiring substrate 3 facing the recording element substrate 2 to prevent the adhesive 5 from spilling out. The grooves 16 formed on the electrical wiring substrate 3 are provided at one end of the electrical wiring substrate 3, between the tip and the position where the connection region 10 is formed. By providing such grooves 16 on the electrical wiring substrate 3, it is possible to prevent the adhesive 5 from spilling out toward the electrode terminals 7 and also to prevent the adhesive 5 from creeping up toward the connection region 10 of the electrical wiring substrate 3. According to this embodiment, adhesion of the adhesive 5 to both components involved in the electrical connection, i.e., the electrode terminal 7 and the connection region 10, can be suppressed, enabling stable wire bonding. In the illustrated example, the groove 16 is formed as a single linear groove, but the shape and number of the grooves 16 can be changed as appropriate depending on the state of overflow of the adhesive 5. For example, the groove 16 can be provided in a U-shape on the surface of the electrical wiring board 3, or the groove 16 may be formed by a plurality of divided grooves.

[0020] [Fourth embodiment] FIG. 5 shows a liquid ejection head 1 according to a fourth embodiment. FIG. 5(a) is a cross-sectional view similar to FIG. 1(c) showing a main portion of a recording element substrate 2, and FIG. 5(b) is a cross-sectional view similar to FIG. 2(a) showing a main portion of the liquid ejection head 1 with an electrical wiring board 3 connected to the recording element substrate 2. The liquid ejection head 1 according to the fourth embodiment is similar to the liquid ejection head 1 according to the first embodiment, but differs in that a surface 17 is formed that forms a step between the recording element substrate 2 and the connection surface 25, and one end of the electrical wiring board 3 is adhesively fixed to the surface 17. The surface 17 is the bottom surface of a recess formed by the step in the connection surface 25, and one end of the electrical wiring board 3 is received and positioned in this recess. The step is formed by removing a portion of the base portion 23 that constitutes the recording element substrate 2. Due to the provision of the surface 17 that forms the step, one end of the electrical wiring board 3 is positioned lower than the position where the electrode terminals 7 are provided on the connection surface 25 of the recording element substrate 2. By forming a step in this way and placing the electrical wiring board 3 on the lower surface 17 formed by the step, it is possible to prevent the adhesive 5 from spilling out toward the electrode terminals 7. Furthermore, since the electrical wiring board 3 has two bonding surfaces to the recording element substrate 2, the adhesive strength is increased, and the electrical wiring board 3 is more firmly fixed to the recording element substrate 2, thereby enabling more stable wire bonding.

[0021] [Fifth embodiment] FIG. 6 shows a liquid ejection head 1 according to a fifth embodiment. FIG. 6(a) is a cross-sectional view similar to FIG. 1(c) showing a main portion of a recording element substrate 2, and FIG. 6(b) is a cross-sectional view similar to FIG. 2(a) showing a main portion of the liquid ejection head 1 with an electrical wiring board 3 connected to the recording element substrate 2. The liquid ejection head 1 according to the fifth embodiment is similar to that according to the first embodiment, but differs in that a convex portion 18 with a flat top surface is provided on the connection surface 25 of the recording element substrate 2, and one end of the electrical wiring board 3 is adhesively fixed to the top surface of this convex portion 18. Based on the position where the electrode terminal 7 is provided on the connection surface 25 of the recording element substrate 2, one end of the electrical wiring board 3 is positioned higher than that position. By adhesively fixing one end of the electrical wiring board 3 to the convex portion 18, the distance from this adhesive portion to the electrode terminal 7 is extended, and therefore, even in this embodiment, overflow of the adhesive 5 toward the electrode terminal 7 can be suppressed.

[0022] [Sixth embodiment] FIG. 7 is a diagram showing a liquid ejection head 1 of a sixth embodiment, and is a cross-sectional view similar to FIG. 2( a ), illustrating a main portion of the liquid ejection head 1 with the recording element substrate 2 and the electrical wiring substrate 3 connected thereto. In the liquid ejection heads 1 of the first to fifth embodiments, the surface on which the electrode terminals 7 are formed on the recording element substrate 2, i.e., the connection surface 25, is the surface opposite to the surface on which the ejection ports 9 are formed. However, the present invention is not limited to this. The electrode terminals 7 may also be provided on the surface on which the ejection ports 9 are formed on the recording element substrate 2, and this surface may serve as the connection surface 25. The liquid ejection head 1 of the sixth embodiment shown in FIG. 7 is the liquid ejection head 1 of the first embodiment, except that the electrode terminals 7 are formed on the surface on which the ejection ports 9 are formed on the recording element substrate 2. The connection region 10 of the electrical wiring substrate 3 is connected to the electrode terminals 7 by wire bonding using the electrical connection member 6. Here, the energy generating elements 8 are assumed to be electrothermal converters, and the energy generating elements 8 and a wiring layer 22 connected to the energy generating elements 8 are formed on one surface of the base portion 23. One surface of the base portion 23 has an area where the ejection port forming member 21 is not laminated, and the wiring layer 22 extends to this area, forming the electrode terminal 7. The electrical wiring board 3 is spaced from the electrode terminal 7, and one end of the electrical wiring board 3 is fixed to one surface of the base portion 23 with an adhesive 5. In this case, the connection area 10 of the electrical wiring board 3 is located on one surface of the base portion 23. The electrode terminal 7 and the connection area 10 are electrically connected by wire bonding using an electrical connection member 6. This electrical connection is sealed with a sealant 4. The structure shown in this embodiment has the advantage that, when applied to a thermal liquid ejection head in which the energy generating elements 8 are arranged on the surface of the pair of surfaces of the base portion 23 on which the ejection port forming member 21 is formed, it is not necessary to form via holes or the like in the base portion 23.

[0023] [Seventh embodiment] FIG. 8 is a perspective view showing a liquid ejection head 1 according to a seventh embodiment. When the number of ejection ports 9 and the number of energy generating elements 8 in the liquid ejection head 1 are increased, the number of electrode terminals 7 must also be increased. The number of electrode terminals 7 also needs to be increased when the drive current supplied to the recording element substrate 2 is large or when the number of signals is large. Because it is difficult to narrow the pitch between the electrode terminals 7 beyond a certain level, in such cases, it is possible to arrange the electrode terminals 7 on both longitudinal sides of the recording element substrate 2. In this case, the electrode terminals 7 are arranged in two rows, and an electric wiring board 3 is provided for each row of the electrode terminals 7, and the electrode terminals 7 and the electric wiring board 3 are electrically connected. As a result, as shown in FIG. 8, two electric wiring boards 3 are connected to the recording element substrate 2 in the liquid ejection head 1, and these two electric wiring boards 3 extend in opposite directions across the recording element substrate 2. Even in this configuration, the configurations described in the first to sixth embodiments can be applied to the electrical connection between the electrode terminals 7 of the recording element substrate 2 and the connection area 10 of the electric wiring board 3. In the above example, when the electrode terminals 7 are formed in two rows, the rows of electrode terminals 7 are formed along each of a pair of long sides of the recording element substrate 2, but the arrangement of the rows of electrode terminals 7 is not limited to this, and the number of rows of electrode terminals 7 can also be three or more. Rows of electrode terminals 7 can be arranged along any side of the recording element substrate 2, and an electric wiring board 3 can be provided for each such row, and the electric wiring board 3 can be electrically connected to the electrode terminals 7 in the corresponding row. In other words, multiple rows of electrode terminals 7 can be provided on the connection surface 25 of one recording element substrate 2, and an electric wiring board 3 can be connected to each row of electrode terminals 7.

[0024] The above describes embodiments to which the present invention can be applied. In recent years, liquid ejection technology or inkjet recording technology has been applied to media other than paper, such as printed wiring boards. Liquid ejection heads used in such applications and liquid ejection devices equipped with liquid ejection heads require high reliability as industrial equipment, and the liquid ejection head based on the present invention can meet this reliability requirement. Furthermore, the liquid ejection head of the present invention can be used to configure a liquid ejection recording device that can maintain high recording quality even during high-speed recording.

[0025] The liquid ejection head according to the present invention is capable of ejecting various liquids in addition to inks used in inkjet recording to perform recording. Furthermore, the liquid ejection head according to the present invention can be used to perform various processes (recording, processing, coating, irradiation, etc.) on various media. The target media here include so-called recording media as well as various media to which a liquid can be applied, whether in sheet form or not, such as paper, plastic, film, textile, metal, flexible substrate, etc. [Explanation of symbols]

[0026] 1 Liquid ejection head 2. Recording element board 3 Electrical wiring board 6 Electrical connection parts 7 Electrode terminal 8 Energy generating element 9 Discharge port 10 Connection Area

Claims

1. a recording element substrate including 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 electrically connected to the electrode terminal; Equipped with the ejection ports are arranged on one surface of the recording element substrate, and the electrode terminals are arranged on the other surface of the recording element substrate, which is the reverse side of the one surface; a connection region including a conductor for electrically connecting with the electrode terminal is provided at an end of the electrical wiring board, the connection region being spaced apart from the electrode terminal and fixed to the other surface by an adhesive; A liquid ejection head, characterized in that a groove is formed on the other surface of the recording element substrate between the connection area and the electrode terminal.

2. A liquid ejection head as described in claim 1, wherein the adhesive is captured in the groove portion.

3. 3. The liquid ejection head according to claim 1, wherein the electrical wiring board does not overlap the electrode terminals when viewed from a direction perpendicular to the other surface of the recording element substrate.

4. 4. The liquid ejection head according to claim 1, wherein the electrode terminal and the conductor are electrically connected by an electrical connection member having one end joined to the electrode terminal and the other end joined to the conductor.

5. 5. The liquid ejection head according to claim 4, wherein the electrical connection member is a bonding wire.

6. 6. A liquid ejection head according to claim 4, wherein an electrical connection portion between said recording element substrate and said electrical wiring substrate, including said electrode terminals, said connection region and said electrical connection member, is sealed with a sealant.

7. The liquid ejection head according to claim 1 , wherein a step is formed on the other surface, and the connection region is disposed on the surface forming the step.

8. A liquid ejection head according to any one of claims 1 to 6, wherein a convex portion is formed on the other surface, the connection area is arranged on the top surface of the convex portion, and the electrode terminal is arranged at a position on the other surface other than the area where the convex portion is formed.

9. 9. The liquid ejection head according to claim 1, wherein a plurality of rows of the electrode terminals are provided on the other surface of the recording element substrate, and the electric wiring substrate is connected to each row of the electrode terminals.

10. the recording element substrate includes an ejection port forming member in which the ejection ports are formed, and a silicon substrate; The liquid ejection head according to claim 1 , wherein the connection region is disposed on a surface of the silicon substrate.

11. The liquid ejection head according to claim 10 , wherein the connection region is disposed on a surface of the silicon substrate opposite to the surface on which the ejection port forming member is provided.

12. A method for manufacturing a liquid ejection head, comprising: a recording element substrate; and an electric wiring substrate electrically connected to the recording element substrate, the 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, the ejection ports being arranged on one surface of the recording element substrate, the electrode terminals being arranged on the other surface of the recording element substrate which is the reverse side of the one surface, and grooves being formed on the other surface, With the recording element substrate supported such that the other surface faces upward, the connection region formed at the end of the electrical wiring substrate is disposed on the other surface of the recording element substrate so that the connection region including the conductor for electrically connecting with the electrode terminal is separated from the electrode terminal across the groove, and the connection region is fixed to the other surface with an adhesive; Thereafter, the electrode terminal and the conductor are electrically connected by wire bonding.

13. A manufacturing method as described in claim 12, wherein when the connection area is fixed to the other surface with the adhesive, any excess adhesive is captured in the groove portion.

14. A manufacturing method described in claim 12 or 13, wherein after electrically connecting the electrode terminal and the conductor, the electrical connection portion between the recording element substrate and the electrical wiring substrate, including the electrode terminal, the connection area and the bonding wire, is sealed with a sealant.

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