Liquid ejection head

Abstract

To provide a technique that can improve reliability on temperature change of an electric wiring board joined to a support member.SOLUTION: A liquid discharge head comprises: a recording element board having an energy generating element that generates energy for discharging liquid from a discharging port; an electric wiring board, electrically connected to the recording element board, which supplies an electric signal for driving the energy generating element; a first support member that supports the recording element board; and a second support member that supports the first support member and is larger in linear expansion coefficient than the electric wiring board. The electric wiring board is joined to a first surface of the first support member and a second surface of the second support member, where an adhesive for joining the electric wiring board to the second surface is lower in elastic modulus than an adhesive for joining the electric wiring board to the first surface.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection head mounted in a liquid ejection recording apparatus. [Background technology]

[0002] A typical liquid ejection recording device includes a liquid ejection head, a carriage on which the liquid ejection head is mounted, a means for transporting the recording medium, and a control means for controlling these. Recording methods include, for example, serial scan and page wide. The serial scan method is a method in which the recording operation is performed while the carriage is moved. The page wide method is a method in which the liquid ejection head, sized to correspond to the width of the recording medium, is used, and the recording operation is performed while the carriage is fixed and the recording medium is transported.

[0003] Compared to serial scan types, page-wide type recording devices can perform more recording simultaneously, resulting in faster recording speeds. For this reason, page-wide type recording devices are adopted as liquid ejection recording devices used for high-speed recording. In page-wide type liquid ejection heads, the print chips (ejection modules) that make up the nozzles that eject liquid are arranged across the entire width of the recording medium.

[0004] The print chip has a recording element substrate equipped with ejection ports for ejecting liquid and energy generating elements for generating energy for ejecting the liquid from the ejection ports. The recording element substrate is electrically connected to other substrates by an electric wiring board to supply electric signals to the recording element substrate for driving the energy generating elements.

[0005] An electric wiring board may be joined and fixed to a support member, for example, by adhesive. The support member may be heated and expanded due to, for example, a heat curing process for hardening a sealing material that insulates an electrical connection portion, or due to a temperature rise during use. The thermal expansion of the support member applies tensile stress to the electric wiring board joined to the support member. This may result in problems such as stress being applied to the electrical wiring of the electric wiring board or peeling of the joint. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6537242 [Patent Document 2] Japanese Patent Application Publication No. 2020-97159 Summary of the Invention [Problem to be solved by the invention]

[0007] As a means of avoiding problems with electrical wiring, Patent Document 1 proposes a method of electrically connecting a support member while it is preheated. By electrically connecting the support member while it is heated, the support member shrinks when it returns to room temperature, causing loosening at the electrical connection. Even if the temperature of the support member rises again, the loosening prevents tensile stress from being applied to the electrical connection.

[0008] However, in a page-wide liquid ejection head in which multiple chips are arranged with high precision, the heating process may reduce the precision of the arrangement. For example, when the ejection modules are arranged on a support member with a large linear expansion coefficient, such as a resin, the influence of heating on the precision of the arrangement becomes more pronounced.

[0009] As a means for improving the reliability of the electric wiring board against temperature changes, Patent Document 2 discloses a method for joining the electric wiring board by providing slack in the electric wiring board using a fixing tool on the device side. We propose a method.

[0010] However, the amount of slack in the electrical wiring board varies depending on the positional deviation of the fixing tool or the variations in the dimensions of the components. Furthermore, when the electrical wiring board is pressed and fixed with the fixing tool, the placement accuracy of the print chip may be reduced.

[0011] An object of the present invention is to provide a technique for improving the reliability of an electric wiring board joined to a support member against temperature changes. [Means for solving the problem]

[0012] A first aspect of the present invention is a recording element substrate having energy generating elements that generate energy for ejecting liquid from ejection ports; an electric wiring board electrically connected to the recording element board and supplying electric signals for driving the energy generating elements; a first support member that supports the recording element substrate; a second support member that supports the first support member and has a linear expansion coefficient greater than that of the electrical wiring board; The electric wiring board is bonded to a first surface of the first support member and a second surface of the second support member, and the electric wiring board is bonded to the second surface. I'm The adhesive bonds the electrical wiring board to the first surface. I'm Lower modulus than adhesives The liquid ejection head is characterized by the above features.

[0013] A second aspect of the present invention is a recording element substrate having energy generating elements that generate energy for ejecting liquid from ejection ports; an electric wiring board electrically connected to the recording element board and supplying electric signals for driving the energy generating elements; a first support member that supports the recording element substrate; a second support member that supports the first support member and has a linear expansion coefficient greater than that of the electrical wiring board; The electrical wiring board is connected to a first surface of the first support member and a Intersection and a third surface of the second support member. The second support member has an end portion of the first surface and a second support member that is in contact with the first surface. Intersection do The aforementioned Between the end of the third surface, With respect to the first surface Incline did has a second surface that is a surface The liquid ejection head is characterized by the above features. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a technique for improving the reliability of an electric wiring board joined to a support member against temperature changes. [Brief explanation of the drawings]

[0015] [Figure 1] 2A and 2B are a perspective view and an exploded view of a liquid ejection head; [Figure 2] 1 is a cross-sectional view of a liquid ejection head according to a first embodiment. [Figure 3] 10A and 10B are diagrams illustrating thermal expansion of a support member. [Figure 4] FIG. 2 is a cross-sectional view of the liquid ejection head according to the first embodiment during thermal expansion. [Figure 5] FIG. 10 is a cross-sectional view of a liquid ejection head according to a second embodiment. [Figure 6] 10A and 10B are diagrams illustrating a second support member of a liquid ejection head according to a second embodiment. [Figure 7] FIG. 10 is a cross-sectional view of a liquid ejection head according to a second embodiment during thermal expansion. DETAILED DESCRIPTION OF THE INVENTION

[0016] First Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a perspective view and an exploded view of a liquid ejection head. A liquid ejection head 10 according to this embodiment is a page-wide type liquid ejection head in which recording element substrates 100 that eject liquid are arranged in the longitudinal direction. The liquid ejection head according to this embodiment is applicable to devices such as printers, copiers, and facsimiles as image forming apparatuses. The liquid ejection head may also be mounted in a device such as a printer as a cartridge formed integrally with a tank that supplies liquid to the liquid ejection head.

[0017] FIG. 1(A) is a perspective view of a liquid ejection head 10 to which this embodiment is applied. FIG. 1(B) is a perspective view of a portion of the liquid ejection head 10. FIG. 1(B) shows a state before an electric wiring board 200 is bent. FIG. 1(C) is a perspective view of each part of the liquid ejection head 10 disassembled. FIG. 1(D) is a cross-sectional view of a recording element substrate 100. FIG. 2 is a cross-sectional view of the liquid ejection head 10 according to the first embodiment. FIG. 2 shows a cross-sectional view of a portion including the electric wiring board 200, of the AA cross section in the perspective view of FIG. 1(B). FIG. 2 shows a state after the electric wiring board 200 has been bent.

[0018] The liquid ejection head 10 has a recording element substrate 100, a first support member 300, a second support member 400, and an electric wiring substrate 200. The recording element substrate 100 has ejection ports 110, electrodes 120, and energy generating elements 130.

[0019] The ejection ports 110 are openings for ejecting ink as a liquid for recording an image on a recording medium, and a plurality of ejection ports 110 are provided on the recording element substrate 100. The electrodes 120 are connected to first connection terminals 210 of the electric wiring substrate 200, and receive electrical signals from the electric wiring substrate 200. The electrodes 120 are connected to the first connection terminals 210 by, for example, wire bonding.

[0020] The energy generating elements 130 are elements that are driven by power supplied from the connection terminals 210 and generate energy for ejecting ink from the ejection ports 110, and are provided opposite each ejection port 110. The energy generating elements 130 are, for example, heat generating resistor elements or piezoelectric elements that generate thermal energy.

[0021] The recording element substrate 100 has a flow path (not shown) for ink to be ejected from the ejection ports 110. The recording element substrate 100 has an opening (not shown) on the back side through which ink supplied from the first support member 300 flows. The ink flow path of the recording element substrate 100 is formed by connecting the opening provided on the back side to the ejection ports 110.

[0022] The first support member 300 has a first surface 901 that supports the recording element substrate 100 and the electric wiring substrate 200. One end of the electric wiring substrate 200 is bonded to the first surface 901 with an adhesive 801.

[0023] The portion of the electric wiring board 200 where the first connection terminals 210 are arranged is bonded to the first surface 901. Therefore, in order to reliably ensure electrical connection with the recording element substrate 100, it is desirable that the electric wiring board 200 be firmly fixed to the first support member 300 on the first surface 901 so that displacement does not occur.

[0024] The first support member 300 has a flow path (not shown) that supplies ink to the recording element substrate 100. An opening 310 through which ink flows is provided on the first surface 901. The first support member 300 has another opening (not shown) on the surface opposite (back side) to the surface on which the opening 310 is provided. A flow path for supplying ink to the recording element substrate 100 is formed by connecting the opening provided on the opposite surface with an opening 310. In order to support the recording element substrate 100, the first support member 300 is preferably made of a reliable material having a predetermined flatness, such as ceramics such as alumina.

[0025] The second support member 400 has a support surface 900 that supports the first support member 300, and has an opening 410 for supplying ink from a liquid supply unit (not shown) such as an ink tank to the first support member 300. The opening 410 communicates with an opening provided on the back side of the opening 310. The second support member 400 is preferably formed from, for example, a resin material containing a filler.

[0026] The second support member 400 also has second surfaces 902 formed on both sides of the support surface 900, extending in the longitudinal direction and positioned higher than the support surface 900. The second support member 400 also has a third surface 903 that is approximately perpendicular to the first surface 901 of the first support member 300. The second surfaces 902 are located between the end of the first surface 901 of the first support member 300 and the end of the third surface 903 that is approximately perpendicular to the first surface.

[0027] Note that the third surface 903 being approximately perpendicular to the first surface 901 does not necessarily mean that the third surface 903 is perpendicular to the first surface 901. The third surface 903 may be a surface extending in a direction forming an angle with respect to the first surface 901 that is greater than or less than 90 degrees.

[0028] As shown in FIGS. 1A and 1B, the second support member 400 supports a plurality of print chip units, each including a recording element substrate 100, an electrical wiring substrate 200, and a first support member 300, arranged in a longitudinal direction. Specifically, the second support member 400 is a support member elongated in a width direction perpendicular to the conveyance direction of the recording medium, and a plurality of print chip units are arranged in the width direction on a single second support member 400. Therefore, due to the difference in size (volume) of the members, the effect of the thermal expansion described above is relatively more pronounced on the second support member 400 than on the first support member 300. Therefore, the conformability of the unit adhesive joints to the second support member 400 becomes important. However, the configuration of the liquid ejection head 10 to which the present invention is applicable is not limited to the configuration exemplified here, and it goes without saying that the target components for which adhesive joint conformability is required are determined relatively depending on the device configuration.

[0029] The electric wiring board 200 supplies electric signals that drive the energy generating elements to the recording element substrate 100. The electric wiring board 200 is joined to the first support member 300 and the second support member 400 in a manner that spans between the first surface 901 and the second surface 902.

[0030] Adhesive 802 that bonds electric wiring board 200 to second surface 902 has a lower modulus of elasticity than adhesive 801 that bonds electric wiring board 200 to first surface 901. Modulus of elasticity is a physical property that indicates resistance to deformation, and is expressed by the relationship between stress and strain in elastic deformation (modulus of elasticity = stress / strain). Modulus of elasticity can be measured, for example, using a DMS (viscoelasticity measuring device) under conditions of 25°C and 10 kHz.

[0031] When the elastic modulus of adhesive 802 is lower than that of adhesive 801, adhesive 802 is relatively more likely to deform than adhesive 801. In this case, the elastic modulus of adhesive 801 is higher than that of adhesive 802, and adhesive 801 is relatively less likely to deform than adhesive 802.

[0032] The reason why the modulus of elasticity of adhesive 801 is set to be higher than the modulus of elasticity of adhesive 802 is to prevent displacement or deformation from occurring in the portion where first connection terminal 210 of electric wiring board 200 is arranged. to the first surface 901 of the first support member 300. By firmly fixing the first connection terminals 210 of the electric wiring board 200 to the first surface 901, the electric wiring board 200 can reliably ensure electrical connection with the recording element board 100.

[0033] The portion of electric wiring board 200 spanning between first surface 901 and second surface 902 may be filled with adhesive 804. It is preferable that adhesive 804 has a lower modulus of elasticity than adhesive 802 that bonds electric wiring board 200 to second surface 902. However, the modulus of elasticity of adhesive 804 only needs to be lower than the modulus of elasticity of adhesive 801 that bonds electric wiring board 200 to first surface 901, and there are no restrictions on the magnitude relationship with the modulus of elasticity of other adhesives.

[0034] Electric wiring board 200 is a flexible wiring board in which a conductive copper foil printed wiring is sandwiched between two thin, soft insulating polyimide films and bonded together. Electric wiring board 200 has a thickness of about 0.1 to 0.3 mm.

[0035] One of the polyimide films sandwiching the copper foil printed wiring is smaller than the other polyimide film, so both ends of the copper foil printed wiring are exposed. The first connection terminal 210 and the second connection terminal 220 are formed on the exposed portions at both ends of the copper foil printed wiring.

[0036] The first connection terminals 210 are electrically connected to the electrodes 120 of the recording element substrate 100 by wire bonding. The second connection terminals 220 are used as connection terminals with the outside, and are electrically connected to an electric substrate 600 that generates electric signals.

[0037] The electrodes 120 of the recording element substrate 100, the first connection terminals 210 of the electrical wiring substrate 200, and the wires connecting the electrodes 120 and the first connection terminals 210 are insulated and coated with a sealing material 500 to prevent electrical failure due to liquid intrusion, etc.

[0038] A cover member 700 is disposed around the recording element substrate 100, forming a surface against which a suction recovery cap for removing bubbles in the flow path comes into contact. The cover member 700 covers the second surface 902 and the third surface 903 of the electric wiring board 200 and the second support member 400. An adhesive 805 may be filled between the cover member 700 and the second support member 400. The elastic modulus of the adhesive 805 only needs to be lower than the elastic modulus of the adhesive 801 that bonds the electric wiring board 200 to the first surface 901, and there are no restrictions on the magnitude relationship with the elastic modulus of the other adhesives.

[0039] The electric wiring board 200 is electrically connected to the recording element board 100. One end of the electric wiring board 200 is joined to the support member 300 at a first surface 901. When joining the cover member 700 to the second support member 400, it is preferable that the electric wiring board 200 be joined to the second support member 400 at a third surface 903 in addition to a second surface 902 to prevent interference with the cover member 700.

[0040] Third surface 903 of second support member 400 is a surface that is approximately perpendicular to first surface 901. Adhesive 803 that bonds electric wiring board 200 to third surface 903 preferably has a lower elastic modulus (is relatively more easily deformed) than adhesive 801 that bonds electric wiring board 200 to first surface 901. In addition, adhesive 803 preferably has a higher elastic modulus (is relatively less easily deformed) than adhesive 802 that bonds electric wiring board 200 to second surface 902.

[0041] That is, it is preferable that the elastic modulus of the adhesives increases in the order of adhesive 801, adhesive 803, and adhesive 802. In electric wiring board 200, the portion where first connection terminal 210 is arranged is firmly fixed to first surface 901, and second surface 902 is joined by adhesive 802, which has a lower elastic force than adhesive 801, in order to absorb tensile stress due to thermal expansion.

[0042] Furthermore, electric wiring board 200 is bonded on third surface 903, which is located farther from first surface 901 than second surface 902, with adhesive 803 having a higher elastic modulus than adhesive 802 on second surface 902. By using adhesive 803 having a higher elastic modulus at positions farther from first surface 901 than at positions closer to first surface 901, electric wiring board 200 can be firmly fixed to each support member.

[0043] With the above-described configuration, the liquid ejection head 10 according to the first embodiment can reduce the tensile stress in the electric wiring board 200 and prevent wiring defects, even when thermal expansion of the second support member 400 occurs due to temperature changes. The tensile stress is a force that occurs inside the electric wiring board 200 when a tensile force from the support member 400 acts on the electric wiring board 200.

[0044] 3, a mechanism for reducing the tensile stress on the electric wiring board 200 when the second support member 400 thermally expands will be described. FIG. 3(A) is a cross-sectional view of the periphery of the electric wiring board 200 at room temperature. The electric wiring board 200 is bonded to a first surface 901 of the first support member 300 and a second surface 902 of the second support member 400 with an adhesive 801 and an adhesive 802, respectively. The third surface 903 and the electric wiring board 200 may be bonded with an adhesive 803.

[0045] First, thermal expansion of a liquid ejection head according to a comparative example will be described with reference to Fig. 3(B). Fig. 3(B) is a cross-sectional view of the periphery of the electric wiring board 200 when the second support member 400 thermally expands toward the cover member 700. Fig. 3(B) shows an example in which an adhesive 802x having a higher elastic modulus than the adhesive 801 used to bond the electric wiring board 200 to the second surface 902 is used. As in the case of Fig. 3(A), the third surface 903 and the electric wiring board 200 may be bonded by the adhesive 803.

[0046] If the adhesive 802x on the second surface 902 has a higher elastic modulus than the adhesive 801 on the first surface 901, the electric wiring board 200 is firmly bound to the first surface 901 and the second surface 902. When the support member 400 thermally expands due to a temperature change, the distance between the end of the first surface 901 and the end of the second surface 902 increases. Because the adhesive 802x on the second surface 902 does not deform, a force is generated in the electric wiring board 200 in a direction in which the portion bonded to the first surface 901 and the portion bonded to the second surface 902 pull against each other, as shown by the arrows in FIG. 3(B).

[0047] For example, if the linear expansion coefficient of second support member 400 is greater than that of electric wiring board 200, a change in the ambient temperature will cause second support member 400 to expand by an amount greater than that of electric wiring board 200. When second support member 400 thermally expands, tensile stress is generated in electric wiring board 200 in accordance with the tensile force indicated by the arrows in FIG. 3(B). The tensile stress may cause wiring problems in electric wiring board 200.

[0048] Next, thermal expansion of the liquid ejection head according to the first embodiment will be described with reference to Fig. 4. Fig. 4 shows an example in which an adhesive 802 having a lower modulus of elasticity than an adhesive 801 for bonding the electric wiring board 200 to the first surface 901 is used as the adhesive for bonding the electric wiring board 200 to the second surface 902. Even if the second support member 400 thermally expands to an amount greater than the amount of thermal expansion of the electric wiring board 200, the adhesive 802 on the second surface 902, which has a lower modulus of elasticity (is relatively more easily deformed), deforms and follows, thereby alleviating the tensile stress on the electric wiring board 200.

[0049] The linear expansion coefficient of the first support member 300 is smaller than that of the second support member 400, and the difference in the linear expansion coefficient between the first support member 300 and the electrical wiring board 200 is This is smaller than the difference in the coefficient of linear expansion between support member 400 and electrical wiring board 200. For this reason, it is necessary to provide a higher degree of conformance to second support member 400 than to first support member 200. For this reason, it is preferable to use, as the adhesive for bonding electrical wiring board 200 to second surface 902, adhesive 802 having a lower modulus of elasticity than adhesive 801 for bonding electrical wiring board 200 to first surface 901.

[0050] Third surface 903 and electric wiring board 200 may be joined by adhesive 803. The modulus of elasticity of adhesive 803 is not particularly limited, but is preferably lower than the modulus of elasticity of adhesive 801. Furthermore, when second support member 400 thermally expands, the tensile stress on the third surface of electric wiring board 200 is smaller than the tensile stress on the second surface. Therefore, adhesive 803, which fixes electric wiring board 200 to second support member 400, preferably has a modulus of elasticity higher than that of adhesive 802. From the viewpoint of cost, it is preferable to use the same type of adhesive rather than using multiple types of adhesives. For example, it is preferable to use the same type of adhesive as adhesive 802 for adhesive 803 and adhesive 805, i.e., to use adhesives with similar moduli of elasticity.

[0051] Second Embodiment In the second embodiment, the configuration different from the first embodiment will be mainly described, and a description of the configuration related to the common parts will be omitted. Fig. 5 is a cross-sectional view of a liquid ejection head 10 according to the second embodiment. Fig. 5 shows a cross-sectional view of a portion including an electric wiring board 200, of the AA cross section in the perspective view of Fig. 1(B).

[0052] The electric wiring board 200 is electrically connected to the recording element board 100, and one end thereof is bonded at a first surface 901 to the support member 300 with an adhesive 801. The electric wiring board 200 is also bonded at a third surface 903 to the second support member 400 with an adhesive 803. The third surface 903 is a surface that is approximately perpendicular to the first surface 901.

[0053] Figure 6 is a diagram illustrating a second support member 400 according to the second embodiment. Figure 6(A) is an enlarged perspective view of the second support member 400 of the liquid ejection head 10 according to the second embodiment. Figure 6(B) is a BB cross-sectional view of the second support member 400 of Figure 6(A) in a state in which the first support member 300, the electric wiring board 200, and the cover member 700 are joined to the second support member 400.

[0054] 6(A) and 6(B), second surface 902 of second support member 400 is an inclined surface that has an angle of 0 degrees or more and less than 90 degrees with respect to first surface 901 of first support member 300. In addition, second surface 902, which is an inclined surface, is formed so as to be lower in the height direction perpendicular to first surface 901 than a joining surface 904 between cover member 700 and second support member 400, i.e., the inner surface of cover member 700.

[0055] 6(B), the bonding surface 904 is formed so as to be at the same height as the first surface 901 of the first support member 300. Therefore, the second surface 902 is formed at a lower position than the first surface 901 in a height direction perpendicular to the first surface 901. Typically, the height direction substantially coincides with the ink ejection direction (opening direction of the ejection ports 110) in the liquid ejection head, but may differ depending on the device configuration.

[0056] With this configuration, a gap is formed between the second surface 902 and the inner surface of the cover member 700. By forming a gap between the second surface 902 and the inner surface of the cover member 700, the electric wiring board 200 is joined to the third surface 903 with slack in the portion that contacts (faces) the second surface 902. Note that the liquid ejection head 10 is not limited to the configurations shown in FIGS. 6(A) and 6(B), and may be configured in any way so long as a gap is formed between the second surface 902 and the inner surface of the cover member 700 and slack is generated in the electric wiring board 200.

[0057] Second surface 902 is formed so that the amount of step between second surface 902 and bonding surface 904 (the distance between second surface 902 and the inner surface of cover member 700) is at least greater than the thickness of electric wiring board 200. With this configuration, slack occurs in the portion of electric wiring board 200 that contacts second surface 902, and even if second support member 400 thermally expands, the tensile stress acting on electric wiring board 200 is reduced.

[0058] 6(B), the joining surface 904 of the second support member 400 is formed to be at approximately the same height as the upper surface of the first support member 300. In other words, the second surface 902 is formed to be lower in height than the upper surface of the first support member 300.

[0059] 5, electric wiring board 200 has a shape with an inclination along the inclined surface (second surface 902) of second support member 400. Since second surface 902 is formed lower than first surface 901, electric wiring board 200 is joined to third surface 903 in a loose state.

[0060] As shown in FIG. 7, even if thermal expansion of the second support member 400 occurs due to a temperature change, the slack in the electric wiring board 200 allows the expansion of the second support member 400 due to the thermal expansion to be absorbed.

[0061] Therefore, no tensile stress is applied to electric wiring board 200 when the temperature changes, and the occurrence of wiring defects is suppressed. Although electric wiring board 200 and second surface 902 are not joined (fixed) to each other, adhesive 804 having a lower elastic modulus (relatively more easily deformed) than adhesive 801 joining electric wiring board 200 to first surface 901 may be filled therebetween. It is more preferable to use adhesive 804 having a lower elastic modulus (relatively more easily deformed) than adhesive 803 joining electric wiring board 200 to third surface 903.

[0062] According to the above configuration, even when the second support member of the liquid ejection head 10 thermally expands due to a temperature change, no tensile stress is applied to the electric wiring board 200, and wiring breakage can be suppressed.

[0063] The above-described embodiments describe preferred modes for the elastic modulus of the adhesive, but are not limited to these modes. It is sufficient that the elastic modulus of adhesive 801 that bonds electrical wiring board 200 to first surface 901 is higher than the elastic modulus of other adhesives 802 to 805, and there are no particular limitations on the magnitude relationship between the elastic moduli of the other adhesives. [Explanation of symbols]

[0064] 10: liquid ejection head, 100: recording element substrate, 200: electric wiring board, 300: first support member, 400: second support member, 801: adhesive for bonding the electric wiring board 200 to the first surface, 802: adhesive for bonding the electric wiring board 200 to the second surface, 901: first surface, 902: second surface

Claims

1. a recording element substrate having energy generating elements that generate energy for ejecting liquid from ejection ports; an electric wiring board electrically connected to the recording element board and supplying an electric signal for driving the energy generating elements; a first support member that supports the recording element substrate; a second support member that supports the first support member and has a linear expansion coefficient larger than that of the electrical wiring board; The electric wiring board is bonded to a first surface of the first support member and a second surface of the second support member, and an adhesive bonding the electric wiring board to the second surface has a lower elastic modulus than an adhesive bonding the electric wiring board to the first surface. A liquid ejection head comprising:

2. The electric wiring board is bonded to a third surface that is substantially perpendicular to the first surface, and an adhesive that bonds the electric wiring board to the third surface has a lower elastic modulus than an adhesive that bonds the electric wiring board to the first surface.

2. The liquid ejection head according to claim 1.

3. The electric wiring board is bonded to the third surface located farther from the first surface than the second surface by an adhesive having a higher elasticity than an adhesive used for bonding to the second surface.

3. The liquid ejection head according to claim 2.

4. a recording element substrate having energy generating elements that generate energy for ejecting liquid from ejection ports; an electric wiring board electrically connected to the recording element board and supplying an electric signal for driving the energy generating elements; a first support member that supports the recording element substrate; a second support member that supports the first support member and has a linear expansion coefficient larger than that of the electrical wiring board; the electrical wiring board is joined to a first surface of the first support member and a third surface of the second support member intersecting the first surface; The second support member has a second surface that is an inclined surface with respect to the first surface between an end of the first surface and an end of the third surface that intersects with the first surface. A liquid ejection head comprising:

5. The second surface is formed at a position lower than the first surface in a height direction perpendicular to the first surface.

5. The liquid ejection head according to claim 4.

6. a cover member that covers the electric wiring board and the second surface and the third surface of the second support member, The second surface is formed to be lower than the inner surface of the cover member in a height direction perpendicular to the first surface.

6. The liquid ejection head according to claim 4, wherein the liquid ejection head is a liquid ejection head.

7. The distance between the second surface and the inner surface of the cover member is greater than the thickness of the electric wiring board.

7. The liquid ejection head according to claim 6.

8. The adhesive that bonds the cover member to the second support member has a lower elastic modulus than the adhesive that bonds the electric wiring board to the first surface.

8. The liquid ejection head according to claim 6, wherein the liquid ejection head is a liquid ejection head.

9. The third surface is approximately perpendicular to the first surface.

9. The liquid ejection head according to claim 4, wherein the liquid ejection head is a liquid ejection head.

10. The second surface is a surface inclined with respect to the third surface.

10. The liquid ejection head according to claim 4,

11. the first surface is a surface to which a portion of the electric wiring board, on which a connection terminal for supplying power to the recording element board is arranged, is joined; 11. The liquid ejection head according to claim 1,

12. The second support member supports a plurality of units, each of which includes the recording element substrate, the electric wiring substrate, and the first support member, in a state in which the units are arranged in a longitudinal direction.

12. The liquid ejection head according to claim 1,

13. A difference in linear expansion coefficient between the first support member and the electric wiring board is smaller than a difference in linear expansion coefficient between the second support member and the electric wiring board.

13. The liquid ejection head according to claim 1,

Images